WO2024172721A1

WO2024172721A1 - Handling cell deactivation

Info

Publication number: WO2024172721A1
Application number: PCT/SE2024/050103
Authority: WO
Inventors: Badawi YAMINE; Henrik RYDÉN; Angelo Centonza
Original assignee: Telefonaktiebolaget LM Ericsson AB
Current assignee: Telefonaktiebolaget LM Ericsson AB
Priority date: 2023-02-15
Filing date: 2024-02-06
Publication date: 2024-08-22
Anticipated expiration: 2025-08-15

Abstract

The present disclosure relates to a method performed by a UE (105) for handling cell deactivation in a communications system (100). The UE (105) is currently served by a second network node (101) in a second cell (103). The UE (105) obtains a cell deactivation time parameter indicating duration of deactivation of coverage of a first cell (103). The UE obtains cell identity information of other cells (103) that may at least partly cover an area of the first cell (103) when the first cell (103) is deactivated. The UE (105) determines that the UE (105) moves away from the second cell (103) and approaches a third cell (103). The UE (105) compares the cell identity of the third cell (103) with the corresponding cell identity in the obtained cell identity information and acts according to a result of the comparison.

Description

HANDLING CELL DEACTIVATION

TECHNCIAL FIELD

The present disclosure relates generally to a User Equipment (UE), a method performed by the UE, a first network node, a method performed by the first network node, a second network node and a method performed by the second network node. More particularly, the present disclosure relates to handling cell deactivation in a communications system. The present disclosure relates to communicating deactivation time, e.g., outage time, between network nodes and other entities in a communications system.

BACKGROUND

In any wireless mobile network, the UE might lose the radio coverage from its serving cell running on a certain Radio Access Technology (RAT), e.g. Fifth Generation (5G). A cell outage may be the cause of the UE losing its radio coverage. Even though this should happen rarely, the UE might however encounter such situation at any time and at any geographical location in the wireless network. The following are some examples of the reasons why a UE might lose its radio coverage from the serving cell, e.g. cell 1 .

Celli goes down due to a planned outage. By planned outage is meant an activity, e.g. a site restart, planned in advance by the operator or by any autonomous tool implemented at the network, e.g. at (Operations Support System (OSS), that takes at a specific time one or more cell down.

Celli goes suddenly into an outage, e.g. due to an equipment failure, e.g. the Radio Unit that feeds cell 1 goes down due to a hardware failure.

The subscriber carrying the UE has moved away from cell 1 radio coverage towards an area where there is no radio coverage, e.g. the subscriber went underground where there is no antenna relay to extend the outside 5G radio coverage to the underground.

The subscriber has moved to an outdoor area where there is a hole of the serving cell radio coverage, e.g., due to lack of good radio coverage optimization that was performed by the operator or due to some other reasons, e.g., obstacles in that area, e.g., tall building etc. Some problems in the prior art:

Problem#1 : With actual standards specifications the duration of the outage is not communicated to neighboring cells

Suppose that, for any reason, a 5G cell, e.g. cell 1 , is subject to an outage for which the outage duration of the cell outage is known.

Actually, based on the latest Third Generation Partnership Project (3GPP) protocols when a cell goes down, the cell’s status is communicated to other entities. However, as it will be described in the following two sections, the duration of the period of outage is not communicated to neighbour nodes. This is a problem because the information about the period of outage may be used to better infer the optimum mobility actions to take at the source Radio Access Network (RAN) node. For example, the source RAN node implementing an Artificial Intelligence (Al)/Machine Learning (ML) based mobility optimisation algorithm, may deduce that in 10 seconds a new neighbour cell will become available and therefore it may predict that it is better to wait to offload UEs, until the currently deactivated cell would become active again. In another example, a RAN node that is aware of an outage for a neighbour cell for a given time window may decide not to take energy saving actions planned for a specific time because those actions may cause lack of coverage and capacity. A deactivated or disabled cell may be referred to as an outage or it may comprise or lead to an outage.

XnAP protocol

If a cell becomes disabled, e.g. the cell is switched off for energy saving reasons, the status of such cell, represented via element “Deactivation Indication”, which is part of the Information Element (IE) “Served Cells To Update NR”, is communicated to neighboring cells as shown in below Table 1 .

Note that the IE “Served Cells To Update NR” is carried via XnAP message NG-RAN NODE CONFIGURATION UPDATE.

Table 1 : Cell status indication in XnAP protocol

F1AP protocol

Based on latest F1 application protocol (F1 AP), i.e. 3GPP specification 38.473, the cell status is communicated between the Next-Generation NodeB Central Unit (gNB-CU) and Next-Generation NodeB Distributed Unit (gNB-DU), however as it is the case with Xn Application Protocol (XnAP) the period of outage is not communicated. This is illustrated as in the below Table 2 and Table 3. In Table 2, from gNB-CU to gNB-DU, extracted from section 9.2.1.10 of 3GPP specification 38.473, v16.12.0, 2023-01-06, the cell status, represented below via Cells to be Deactivated List Item, is communicated via F1AP message GNB-CU CONFIGURATION UPDATE Table 2 - Cell status communicated in 38.473 from gNB-CU to gNB-DU

InTable 3, gNB-DU -> gNB-CU, the cell status, represented below via Service Status, is communicated via F1AP message GNB-DU CONFIGURATION UPDATE.

Table 3 - Cell status communicated in 38.473 from gNB-DU to gNB-CU

Problem#2: The duration of the outage is not communicated to the UE in neighboring cells

Suppose that one cell, e.g. 5G cell 1 has another 5G cell, e.g. 5G cell2, among other adjacent neighbors, and that the area of 5G cell 1 is covered also by a Fourth Generation (4G) cell, e.g. 4G cell 1 . Actually, when 5G cell 1 goes into outage the value of the period of outage, it is NOT communicated to neighbors of 5G cell 1 that are of the same RAT as 5G cell 1 , e.g. neighbor 5G cell2. As a consequence, after 5G cell 1 outage, a UE that is moving from 5G cell2 towards the direction of 5G celU it will detect radio coverage of 4G celU and as a result depending on whether the UE is in idle mode or inactive mode or in connected mode it will experience one of the following two issues:

Issue 1 : For a UE idle mode or inactive mode, e.g. UE1 , moving from 5G cell2 towards areal _after_cell1_outage as it will detect radio signal from 4G celU , THEN, based on actual standard procedures it will camp on 4G cell 1 and will trigger, without any delay, a signaling procedure on 4G cell 1 , e.g. attach procedure to 4G network and a location update procedure, etc.

After, duration of the cell outage has expired, as UE1 will detect again radio coverage form 5G cell 1 it will camp on 5G cell 1 and then again based on actual standard procedures it will trigger other signaling procedures on 5G cell 1 , e.g. a location update on 5G celU etc.

As a result, Issue 1 consists of having UE1 triggering a first set of signaling procedures on 4G celUwhen the outage on 5G celU was executed and a second set of signaling procedures on 5G celU after the outage is ceased. This is a problem when considering that, in a 5G cell, thousands of UEs, e.g. including smart sensors of all types, might be triggering this ping pong set of procedures on the 4G cell and then on the 5G cell.

Issue 2: For a UE in connected mode. Due to air interface capacity and network latency, it might happen that some type of call applications works on one RAT but do not work on other RAT. In one example, an application that works on Sixth Generation (6G) but not on 5G nor on 4G. In another example, some type of call applications works on 5G but do not work on 4G nor on Third Generation (3G).

Suppose that a UE, e.g., UE2, running an application that is supported by 5G but not supported by a 4G, is moving from 5G cell2 towards the area of 5G celU outage. In prior art, once UE2 detects the radio coverage of 4G celU , it will trigger an inter-RAT handover procedure from 5G cell2 towards 4G celU . BUT in this example, as UE2 is running an application that is not supported by 4G cell, the inter-RAT handover is rejected and while UE2 is moving towards the area of 4G celU at a certain time it will lose its connection from 5G cell2, hence it will release a drop call. Once it is in idle or inactive mode on 4G celU it could trigger a new call setup of any type of call that is supported by 4G cell. Such UE2 behavior is considered as a problem.

Therefore, there is a need to at least mitigate or solve this issue.

SUMMARY An objective is to obviate at least one of the above disadvantages and to improve handling of cell deactivation in a communications system.

According to a first aspect, the objective is achieved by a method performed by a UE for handling cell deactivation in a communications system. The UE is currently served by a second network node in a second cell. The UE obtains a cell deactivation time parameter indicating duration of deactivation of coverage of a first cell. The first cell is a neighbor cell to the second cell. The UE obtains cell identity information of other cells that may at least partly cover an area of the first cell when the first cell is deactivated. The UE determines that the UE moves away from the second cell and approaches a third cell. The UE compares the cell identity of the third cell with the corresponding cell identity in the obtained cell identity information. The UE acts according to a result of the comparison.

According to a second aspect, the objective is achieved by a UE for handling cell deactivation in a communication system. The UE is arranged to be currently served by a second network node in a second cell. The UE is arranged to obtain a cell deactivation time parameter indicating duration of deactivation of coverage from of a first cell. The first cell is a neighbor cell to the second cell. The UE is arranged to obtain cell identity information of other cells that may at least partly cover an area of the first cell when the first cell is deactivated. The UE is arranged to determine that the UE moves away from the second cell and approaches a third cell. The UE is arranged to compare the cell identity of the third cell with the corresponding cell identity in the obtained cell identity information. The UE is arranged to, based on a result of the comparison, determine to camp on the third cell with or without performing a prior art signaling procedure, or to wait until the cell deactivation time has expired. The UE is arranged to act according to a result of the comparison.

According to a third aspect, the objective is achieved by a method performed by a first network node for handling cell deactivation in a communications system. The first network node serves a first cell. The first network node provides, to a second network node, a cell deactivation time parameter indicating duration of deactivation of coverage from a first cell. The first cell is a neighbor cell to the second cell served by the second network node. The first network node provides, to the second network node, cell identity information of other cells that may at least partly cover an area of the first cell when the first cell is deactivated.

According to a fourth aspect, the objective is achieved by a first network node for handling cell deactivation in a communications system. The first network node is arranged to serve a first cell. The first network node is arranged to provide, to a second network node, a cell deactivation time parameter indicating duration of deactivation of coverage from a first cell. The first cell is a neighbor cell to the second cell served by the second network node. The first network node is arranged to provide, to the second network node, cell identity information of other cells that may at least partly cover an area of the first cell when the first cell is deactivated.

According to a fifth aspect, the objective is achieved by a method performed by a second network node for handling cell deactivation in a communications system. The second network node serves a second cell. The second network node obtains, from a first network node, a cell deactivation time parameter indicating duration of deactivation of coverage from a first cell. The first cell is a neighbor cell to the second cell. The second network node provides the cell deactivation time parameter to a UE. The second network node obtains, from the first network node, cell identity information of other cells that may at least partly cover an area of the first cell when the first cell is deactivated. The second network node provides the cell identity information to the UE.

According to a sixth aspect, the objective is achieved by a second network node for handling cell deactivation in a communications system. The second network node is arranged to serve a second cell. The second network node is arranged to obtain, from a first network node, a cell deactivation time parameter indicating duration of deactivation of coverage from a first cell. The first cell is a neighbor cell to the second cell. The second network node is arranged to provide the cell deactivation time parameter to a UE. The second network node is arranged to obtain, from the first network node, cell identity information of other cells that may at least partly cover an area of the first cell when the first cell is deactivated. The second network node is arranged to provide the cell identity information to the UE. According to a seventh aspect, the objective is achieved by computer program product comprising program code for performing, when executed by the processing circuitry, the method of any of the first, third and/or fifth aspects.

According to an eight aspect, the objective is achieved by a non-transitory computer- readable storage medium comprising instructions, which when executed by the processing circuitry, cause the processing circuitry to perform the method of any of the first, third and/or fifth aspects.

Thanks to the cell deactivation time parameter indicating duration of deactivation of coverage from a first cell, the handling of cell deactivation in the communications system is improved.

The present disclosure herein affords many advantages, of which a non-exhaustive list of examples follows:

When a cell outage occurs, the communication of the cell deactivation time parameter, e.g. a value of the estimated period of outage, cell deactivation time parameter, may bring the following advantages:

When the cell deactivation time parameter is communicated between the network nodes, such information may be used to better infer the optimum mobility actions or energy saving actions to take at the source network node. For example, the source network node implementing an AI/ML based mobility optimisation algorithm, may deduce that in 10 seconds a new neighbour cell will become available and therefore it may predict that it is better to wait to offload UEs, until the currently deactivated cell would become active again. This could have a good added value for the network equipment vendors as well as for the operators.

The case when a UE is running an application that works on a first RAT, e.g. 5G but does not work on a second RAT, e.g. 4G. Suppose that a 5G cell, e.g. 5G cell 1 , goes into an outage and that a 4G cell, e.g. 4G cell 1 , covers the area of 5G cell 1 . By communicating the value of cell deactivation time parameter of 5G cell 1 to all its neighbour cells, in particular to 5G neighbour cells, e.g. 5G cell2, THEN when a UE that is running an application that works on 5G and that is moving towards the area of 5G cell 1 , detects the radio signal of 4G cell 1 , its behaviour will be as follows:

In prior art, the 5G call is dropped and there is no way to resume it when 5G cell 1 outage is ceased.

- With the present disclosure, when the UE has moved, after the outage, to the area of 5G cell 1 and has detected radio signal from 4G cell 1 , there is a chance that the 5G call that was suspended on 4G cell 1 to be resumed on 5G cell 1 after the outage on 5G cell 1 is ceased. This could have a good added value for the manufacturers of UE and for the subscriber as well.

Instead of communicating the value of the cell deactivation time parameter over the air interface which requires few bits of coding in the Radio Resource Control (RRC) protocol, the value of the cell deactivation time parameter might be hardcoded in the UE and in such scenario, as it will be described in later, and in such scenario only 1 bit is needed in the RRC protocol.

The present disclosure is not limited to the features and advantages mentioned above. A person skilled in the art will recognize additional features and advantages upon reading the following detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure will now be described in more detail by way of example only in the following detailed description by reference to the appended drawings in which:

Fig. 1 is a schematic drawing illustrating a communications system.

Fig. 2 is a flow chart illustrating a method.

Fig. 3 is a flow chart illustrating a method.

Fig. 4 is a schematic drawing illustrating the communications system before 5G celU outage.

Fig. 5 is a schematic drawing illustrating the communications system after 5G celU outage.

Fig. 6 is a flow chart illustrating a method.

Fig. 7 is a schematic drawing illustrating the communications system after 5G celU outage. Fig. 8 is a flow chart illustrating a method.

Fig. 9 is a flow chart illustrating a method.

Fig. 10 is a flow chart illustrating a method.

Fig. 11 is a flow chart illustrating a method.

Fig. 12 is a flow chart illustrating a method.

Fig. 13a is a schematic drawing illustrating a UE.

Fig. 13b is a schematic drawing illustrating a UE.

Fig. 14a is a schematic drawing illustrating a network node.

Fig. 14b is a schematic drawing illustrating a network node.

Fig. 15 is a schematic drawing illustrating of a communications system.

Fig. 16 is a block diagram illustrating a host.

Fig. 17 shows a communication diagram of a host communicating via a network node with a UE over a partially wireless connection.

The drawings are not necessarily to scale, and the dimensions of certain features may have been exaggerated for the sake of clarity. Emphasis is instead placed upon illustrating the principle.

DETAILED DESCRIPTION

Fig. 1 depicts a non-limiting example of a communications system 100, which may be a wireless communications system, sometimes also referred to as a wireless communications network, cellular radio system, or cellular network, in which the present disclosure may be implemented. The communications system 100 may be a 5G system, 5G network, NR-U or Next Gen system or network. The communications system 100 may alternatively be a younger system or older system than a 5G system, such as e.g. a 2G system, a 3G system, a 4G system, a 6G system a 7G system etc. The communications system 100 may support other technologies such as, for example, Long-Term Evolution (LTE), LTE-Advanced/LTE-Advanced Pro, e.g. LTE Frequency Division Duplex (FDD), LTE Time Division Duplex (TDD), LTE Half-Duplex Frequency Division Duplex (HD-FDD), LTE operating in an unlicensed band, NB-loT. Thus, although terminology from 5G/NR and LTE may be used in this disclosure to exemplify, this should not be seen as limiting to only the aforementioned systems. The communications system 100 comprises one or a plurality of network nodes, whereof a first network node 101a and a second network node 101 b are depicted in the nonlimiting example of fig. 1 . Any of the first network node 101 a, and the second network node 101 b may be a radio network node, such as a radio base station, or any other network node with similar features capable of serving a user equipment, such as a wireless device or a machine type communication device, in the communications system 100. The first network node 101 a may be an eNB and the second network node 101 b may be a gNB. The first network node 101 a may be a first eNB, and the second network node 101 b may be a second eNB. The first network node 101 a may be a first gNB, and the second network node 101 b may be a second gNB. The first network node 101 a may be a MeNB and the second network node 101 b may be a gNB. Any of the first network node 101 a and the second network node 101 b may be co-localized, or they may be part of the same network node. The first network node 101 a may be referred to as a source node or source network node, whereas the second network node 101 b may be referred to as a target node or target network node. When the reference number 101 is used herein without the letters a or b, it refers to a network node in general, i.e. it refers to any of the first network node 101 a or second network node 101 b.

The communications system 100 covers a geographical area which may be divided into cell areas, wherein each cell area may be served by a network node, although, one network node may serve one or several cells. In fig. 1 , the communications system 100 comprises a first cell 103a and a second cell 103b. Note that two cells are exemplified in fig. 1 only as an example, and that any n number of cells may be comprised in the communication system 100, where n is any positive integer. A cell is a geographical area where radio coverage is provided by the network node at a network node site. Each cell is identified by an identity within the local network node area, which is broadcast in the cell. In fig. 1 , first network node 101 a serves the first cell 103a, and the second network node 101 b serves the second cell 103b. Any of the first network node 101 a and the second network node 101 b may be of different classes, such as, e.g., macro base station (BS), home BS or pico BS, based on transmission power and thereby also cell size. Any of the first network node 101 a and the second network node 101 b may be directly connected to one or more core networks, which are not depicted in fig. 1 for the sake of simplicity. Any of the first network node 101 a and the second network node 101 n may be a distributed node, such as a virtual node in the cloud, and it may perform its functions entirely on the cloud, or partially, in collaboration with another network node. The first cell 103a may be referred to as a source cell, whereas the second cell 103b may be referred to as a target cell. When the reference number 103 is used herein without the letters a or b, it refers to a cell in general, i.e. it refers to any of the first cell 103a or second cell 103b.

One or a plurality of UEs 105 is comprised in the communication system 100. Only one UE 105 is exemplified in fig. 1 for the sake of simplicity. A UE 105 may also be referred to simply as a device. The UE 105, e.g. an LTE UE or a 5G/NR UE or a 6G UE, may be a wireless communication device which may also be known as e.g., a wireless device, a mobile terminal, wireless terminal and/or mobile station, a mobile telephone, cellular telephone, or laptop with wireless capability, just to mention some examples. The UE 105 may be a device by which a subscriber may access services offered by an operator’s network and services outside operator’s network to which the operator’s radio access network and core network provide access, e.g. access to the Internet. The UE 105 may be any device, mobile or stationary, enabled to communicate over a radio channel in the communications system 100, for instance but not limited to e.g. UE, mobile phone, smart phone, sensors, meters, vehicles, household appliances, medical appliances, media players, cameras, Machine to Machine (M2M) device, Internet of Things ( IOT) device, terminal device, communication device or any type of consumer electronic, for instance but not limited to television, radio, lighting arrangements, tablet computer, laptop or Personal Computer (PC).The UE 105 may be portable, pocket storable, hand held, computer comprised, or vehicle mounted devices, enabled to communicate voice and/or data, via the radio access network, with another entity, such as another UE, a server, a laptop, a Personal Digital Assistant (PDA), or a tablet, Machine-to-Machine (M2M) device, device equipped with a wireless interface, such as a printer or a file storage device, modem, or any other radio network unit capable of communicating over a radio link in the communications system 100.

The UE 105 is enabled to communicate wirelessly within the communications system 100. The communication may be performed e.g. between two UEs 105, between a UE 105 and a regular telephone, between the UE 105 and a network node, between network nodes, and/or between the UE 105 and a server via the radio access network and possibly one or more core networks and possibly the internet. The first network node 101 a may be configured to communicate in the communications system 100 with the UE 105 over a first communication link 108a, e.g., a radio link. The second network node 101 b may be configured to communicate in the communications system 100 with the UE 105 over a second communication link 108b, e.g., a radio link. The first network node 101 a may be configured to communicate in the communications system 100 with the second network node 101b over a third communication link 108c, e.g., a radio link or a wired link, although communication over more links may be possible. When the reference number 108 is used herein without the letters a, b or c, it refers to a communication link in general, i.e. it refers to any of the first communication link 108a, the second communication link 108b and the third communication link 108c.

It should be noted that the communication links 108 in the communications system 100 may be of any suitable kind comprising either a wired or wireless link. The link may use any suitable protocol depending on type and level of layer (e.g. as indicated by the Open Systems Interconnection (OSI) model) as understood by the person skilled in the art.

A new parameter, denoted here as cell deactivation time parameter, is communicated between network nodes 101 , e.g. between two radio nodes. The cell deactivation time parameter, e.g. the value of the cell deactivation time parameter, may be provided from a network node 101 to all UEs 105 in the cell 103 whether they are in idle or inactive or in connected mode, together with a list of cell identity, e.g. Physical Cell Identity (PCI), of neighboring cells.

The cell deactivation time parameter, e.g. the value of the cell deactivation time parameter, may be provided only to UEs 105 that are in connected mode and in addition they are running an application that works on serving cell, e.g. running on RAT 1 , but not on a neighboring cell, e.g. running on another RAT2.

The cell deactivation time parameter may indicate the time of duration of a cell deactivation. Cell deactivation may be referred to as cell outage. During cell deactivation, a UE 105 in coverage of a network node 101 serving the deactivated cell will not receive any signals from the network node 101 and/or deactivated cell. The cell deactivation time parameter may have a value, e.g., 4 milliseconds, 8 milliseconds, 1 second, 2 seconds or any other suitable value.

A deactivated or disabled cell may be referred to as an outage or it may comprise or lead to an outage.

How to determine the cell deactivation time parameter

A cell outage, also referred to as cell deactivation, may be classified into one of the following two categories:

- Case 1 : A planned cell outage.

- Case 2: An unexpected cell outage.

Case 1 : A planned outage is executed at the cell 103

The following are three examples of planned cell outage activities:

- A cell lock/unlock: such activity might be required on some occasions in order to make the change of some parameters on the cell 103 to take effect.

- A site restart, which is needed on many occasions, e.g. when a new software has to be downloaded on the network node 101. In fact, every period of time a software upgrade is required in the network node 101 in order to take into considerations new features proposed by the standards or by the equipment vendors and/or new solutions to previous software issues etc.

- Automatic cell lock/unlock or automatic site restart that is triggered by troubleshooting autonomous tools installed at OSS or at the network node side. In one example, the operator could configure such tools to execute the following action: When a particular fault or alarm appears then a cell lock/unlock, or a site restart might be automatically triggered by that tool.

In such case, examples of how the cell deactivation time parameter may be calculated with an accuracy above an accuracy threshold, e.g. a high accuracy, are given below:

- A UE 105 is camped on a cell, e.g., celH . After restarting the network node 101 , e.g. RN1 , that is carrying celH , the difference in time between time t1 when the UE 105 has lost its radio coverage due to RN1 restart and time t2 when the UE 105 detects again radio signal from cell1 103 will be equal to the cell deactivation time parameter. Note that the calculation of t1 and t2 could be performed by a tester who just looks at the presence and absence of radio signal on his mobile phone or for a more accuracy by a software tool that is implemented for that purpose at a UE side. Note that the value of the cell deactivation time parameter differs for each type of cell outage, e.g., for cell lock/unlock activity the value of the cell deactivation time parameter might be less than the value of the cell deactivation time parameter in case a site restart is executed. However, herein the cell deactivation time parameter is used independently of the activity as the proposed methods work independently of the activity of the cell outage.

- The cell deactivation time parameter may take a preplanned value, e.g., configured by the operator at the OSS system and signalled to network nodes 101. In this case even triggering a cell outage might be associated to a different cell deactivation time parameter duration. For example, the value of the cell deactivation time parameter in cases of cell outage due to cell parameters configuration changes might be shorter than the cell deactivation time parameter used for cell outages due to a network node software upgrade.

Case 2: A cell 103 goes unexpectedly into an outage

It might always happen that, at any time, one cell 103 in the communications system 100 goes down. This could be, like any other electronic equipment, due to a software or a hardware issue. In such a scenario, the accuracy of the estimation of the cell deactivation time parameter might not always be high. In many scenarios that outage period might be a high value, e.g. few minutes. The following is an example of the calculation of the cell deactivation time parameter when a cell goes unexpectedly into an outage:

An alarm, e.g. denoted alarml , appears on OSS and a cell 103 is down. An autonomous tool at OSS, e.g. denoted tooll , will try to clear the alarm using a set of preconfigured actions and hence rectify the cell 103. Suppose that the alarm is about an issue on the Radio Unit (RU) that is connected to the cell 103. The RU is comprised in the network node.

In one example, one action of tooll is to restart the RU and if it does not work maybe restart the whole site.

Note that if alarml has occurred at previous instances then, If a restart RU has cleared it, hence has restored celll 103, THEN one action of tooll is to send a notification to all the neighbors of celll 103 indicating to them the cell deactivation time parameter which is here equal to the value of a duration of a RU restart.

Otherwise, if for alarml a restart RU is not helpful and a site visit is needed to replace the RU, then tooll might send a notification to all neighbor cells of celll 103 telling them that the value of the cell deactivation time parameter is infinite, e.g., when the time to visit site and replace the RU exceeds a certain configured number of minutes.

Note that in this latest example, e.g. when a site visit to replace the hardware of the network node 101 is needed or in other scenarios the setting of the value of the cell deactivation time parameter might be set by the operator by simply writing the value, e.g.

2 hours, on OSS and that value will be dispatched to the neighboring cells 103. in cases of a non-planned cell outage due to failures or unexpected events, the value of the cell deactivation time parameter might be set by means of historical values collected for the same event(s) causing the outage. Alternatively, the value of the cell deactivation time parameter might be calculated by an AI/ML algorithm which might take as inputs the events and data preceding the failure/unexpected event and inferring the outage time for the cell 103.

Communicating the period of the deactivation between network nodes 101

When a cell outage occurs in the communications system 100, the network node 101 serving the cell 103 in outage or for other nodes/systems, e.g., the OSS, knowing of the cell outage event, to communicate to network nodes 101 serving cells 103 neighbouring the cell 103 in outage and other network entities, the value of the estimated period of outage, denoted herein as the cell deactivation time parameter.

Initial state:

Once, cell, e.g., 5G celll went into an outage.

The expected period of outage is represented by the cell deactivation time parameter. This may be applied to a network node to network node interface, e.g. a RAN node to RAN node interface, e.g. the XnAP protocol, and/or to a network node internal interface, e.g. RAN node internal interface, e.g. the F1AP protocol. Communicating the cell deactivation time parameter via XnAP protocol

An IE, e.g., denoted here cell deactivation time parameter, may be added to an existing or new message signalled over a peer to peer interface between network nodes 101 . This IE may be added to the Served Cells To Modify NR IE, signalled over the Xn interface in addition to the “Deactivation Indication”. Such parameter may be denoted ‘Cell deactivation time’ and it might represent the value of the cell deactivation time parameter. This is exemplified in Table 4 below.

Table 4 - Example of addition of the Cell deactivation time, expressing the duration of the cell deactivation time parameter

By signalling the cell deactivation time, a first network node 101 informs a second network node 101 about the time a served cell might be out of service. This helps the second network node 101 to optimize and better manage the following processes: It helps optimize mobility and load balancing. o In one example the second network node 101 may modify the neighbour relations between the cell in outage and its served neighbouring. For example, if the Cell deactivation time is higher than a certain value, neighbour cell relations with the cell in outage might be removed. o In another example, the second network node 101 may take optimized decisions concerning traffic offload actions. For instance, if the cell 103 in outage will be activated in the near future, the second network node 101 may wait to offload traffic to other cells 103 and offload, i.e. handover, UEs 105 to the cell 103 in outage, once it has become active again. o In another example, the second network node 101 may decide to handover the UE 105 on target cells 103 that are not the best targets from a radio signal point of view. The reason is that such other target cells 103 may be using a different frequency layer from the source and outage cell 103 and on such frequency layer coverage might be uniform and not subject to discontinuity, while on the frequency layer of the source and outage cell coverage is discontinuous due to the outage.

It helps optimize Energy Saving. o In one example, the second network node 101 , knowing the duration of the cell deactivation time, can take better decisions on energy saving actions such as cell deactivations. If the cell 103 in outage is, for example, covering an area also in part or in full covered by a cell 103 that is planned to be deactivated for energy saving reasons, the second network node 101 may decide to delay the energy saving cell deactivation until the cell in outage returns into operation, namely until after the cell deactivation time expires.

The cell deactivation time also helps the second network node 101 to take better AI/ML based decisions. o In one example, the second network node 101 is able to use the cell deactivation time for the cell 103 in outage as one of the inputs to perform inference on mobility optimization actions or on load balancing actions or on energy saving actions. For instance, the second network node 101 may predict what will be the radio condition of its served UEs 105 once the cell deactivation time expires and the cell 103 in outage returns into operation. This would allow to anticipate or to delay UE mobility and offloading actions until the cell deactivation time expires.

Communicating the cell deactivation time parameter via F1AP protocol

An IE may be added to an existing or new message signalled over a RAN internal interface. In one example, this IE may be added to the Cells to be Deactivated List IE or to the Cells Status List IE, signalled over the F1 interface.

In the direction gNB-CU 101 to gNB-DU 101 : A parameter, denoted here as Cell deactivation time and which represent the value of the cell deactivation time parameter, may be added under existing ‘Cells to be Deactivated List Item’ as shown in Table 5 below.

Table 5 - Adding the parameter ‘Cell deactivation time’ to existing standards in direction gNB-CU to gNB-DU

The gNB-CU 101 in this case knows the duration of the cell deactivation time and communicates it to the gNB-DU 101 . The gNB-DU 101 may benefit of knowing such parameter, some examples are provided below:

The gNB-DU 101 is able to better manage its served cells and to optimize cells shape in order to cover for the lack of coverage coming from the cell outage. With the cell deactivation time the gNB-DU 101 is also able to pre-plan when cell shapes will be reversed to the status in place before the cell outage occurred.

The gNB-DU 101 is able to optimize layer 1 /Layer 2 mobility for UEs 103 moving among its served cells. As an example, the gNB-DU 101 is able to take optimize L1/L2 mobility actions with knowledge that the cell in outage will remain out of service for the cell deactivation time In the direction gNB-DU 101 to gNB-CU 101 : A parameter, denoted here as ‘Cell deactivation time’ and which represent the value of the cell deactivation time parameter, may be added under existing ‘Cells Status Item’ as shown in Table 6 below.

Table 6 - Adding parameter ‘Cell deactivation time’ to existing standards in direction gNB-DU 101 to gNB-CU 101

In this case, the gNB-CU 101 is not aware of the cell deactivation time, but the gNB-DU 101 knows for how long a cell 103 will need to remain deactivated. This might be due to the fact that the gNB-DU 101 is aware of the event that is triggering the cell outage and its duration. The gNB-CU 101 may benefit of knowing such parameter, some examples are provided below:

The gNB-CU 101 is able to better manage traffic offloading and mobility within its cells by knowing that the cell 103 in outage will remain out of service for the cell deactivation time.

The gNB-CU 101 is able to better manage traffic offloading and mobility with neighbor nodes. As an example, the gNB-CU 101 is able to reject offloading requests from neighbouring network nodes 101 in view of the fact that traffic served by the cell 103 in outage will need to be redistributed among its cells 103, hence increasing the load per cell 103.

The gNB-CU 101 is able to better perform predictions on mobility, radio conditions, energy efficiency actions, by knowing that for the cell deactivation time the cell in outage will be out of service while after expiration of the cell deactivation time it will be back in service, hence generating new radio and mobility conditions. Communicating cell deactivation time parameter via the OSS

An alternative method to singalling the ‘Cell deactivation time’ via network node 101 to network node 101 , or via network node internal interfaces consists of using OSS. In one example, if between gNB1 101 and eNB1 101 there is no Xn interface then when a cell 103 in one network node 101 goes down, e.g., celH 103 of gNB1 101 goes down, then gNB1 101 communicates to eNB1 101 the status of celH 103, i.e. information 1 , and the value of cell deactivation time parameter, i.e. information 2, via the OSS. In fact, gNB1 101 could send a new notification to the OSS that comprises information 1 and information 2 with target node equal to eNB1 101 . Once the new notification is received at the OSS it will send another OSS notification to eNB1 101 comprising information 1 and information 2.

Fig. 2 is a flow chart illustrating a method. The method is performed by a network node 101 , e.g., the first network node 101 and/or the second network node 101. The method comprises at least one of the following steps, which steps may be performed in any suitable order than described below.

Step 200

Two procedures to calculate the value of the cell deactivation time parameter:

1 ) In case of a cell planned outage a value of cell deactivation time parameter for each type of outage, e.g. a cell lock/unlock, a site restart etc., might be calculated in advance, e.g. the tester takes a first timestamp, timestampl , when the UE 105 loses its radio coverage due to a restart of a network node 101 . After network node recovery the tester takes another timestamp, timestamp2, at time the UE receives again radio coverage. In such a test, cell deactivation time parameter for cell 1 = timestamp2 - timestampl .

2) In case of a non-planned cell outage due to failures or unexpected events, the value of the cell deactivation time parameter might be set by means of historical values collected for the same event(s) causing the outage. Alternatively, the value of the cell deactivation time parameter might be calculated by an AI/ML algorithm which might take as inputs the events and data preceding the failure/unexpected event and inferring the outage time for the cell. Step 210

The value of the cell deactivation time parameter may be communicated between the network nodes 101 . Below are two alternatives of how the parameter is communicated between the network nodes 101 :

1 ) An IE, denoted ‘Cell dactivation time’ that represent the value of cell deactivation time parameter, is added to an existing or new message signalled over a peer to peer interface between network nodes 101 . Such IE could be added to XnAP protocol and to F1AP protocol.

2) An alternative method to singalling the ‘Cell dactivation time’ via network node 101 to network node 101 or via network node internal interfaces consists of using OSS.

Following are some examples of benefits from communicating the cell deactivation time parameter between network nodes 101 :

It helps optimizing mobility and load balancing.

It helps optimizing energy saving.

The cell deactivation time also helps the second network node 101 to take better AI/ML based decisions.

Dual or multi-connectivity operation -> don’t setup dual connectivity with the outage cell.

Carrier aggregation -> don’t setup CA with the to be outage cell.

Network node actions upon reception of outage period

Action 1 : Setting network node configuration parameters

Upon reception of the outage period of the neighboring cell, the neighboring cell 103 could, in addition to the examples listed earlier for example configure parameters related to the following procedures:

T raffic/load balancing -> avoid configuring UEs 105 to measure on the outage cell 103 for load distribution procedures. mobility operations -> avoid configuring UEs 105 to perform a handover on the outage cell 103. For example, by setting specific parameters related to the handover events. dual or multi-connectivity operation -> don’t setup dual connectivity with the outage cell 103. Carrier aggregation (CA) -> don’t setup Carrier aggregation with the to be outage cell 103.

Energy savings operations/settings -> Avoid energy saving operation modes when a neighboring cell 103 goes into planned outage.

Action 2: Communicating the period of outage to all UEs 105 in neighboring cells 103 Once the cell deactivation time parameter is received by a network node 101 in a neighbor cell 103, e.g. 5G cell2 , the network node 101 in cell2 103 broadcasts the cell deactivation time parameter to all UEs 105 in cell2 103. This may be described with the below steps, which are also illustrated in fig. 3. Fig. 3 is a flow chart illustrating a method where a 4G cell 103 with PCI11 will be covering the area of 5G celU 103 after the outage on 5G celU 103 is executed. The method in fig. 3 comprises at least one of the following steps, which steps may be performed in any suitable order than described below:

Initial state:

Once cell 103, e.g., celU of RAT1 , e.g. 5G, that covers one geographical area, denoted areal , goes into outage at t1 .

The period of the planned outage on celU 103 is known and it is denoted cell deactivation time parameter.

An outage is planned at time t1 on 5G celU that covers one geographical area, denoted areal .

The value of cell deactivation time parameter that represents the duration of outage of celU 103 is communicated to all neighbors of 5G celU 103, e.g. 5G cell2 103.

Step 300:

Cell deactivation time parameter is communicated via new Xn or F1 procedure to network nodes 101 in all neighbors of celU 103, e.g., 5G cell2 103. The received cell deactivation time parameter is communicated, via new XnAP and F1AP procedures (described above), to all UEs 105 in cells 103 that are neighbors to 5G celll 103.

Once the cell deactivation time parameter is received by a network node 101 in a neighbor cell 103, 5G cell2 103, that value is then communicated on the air interface to all the UEs 105 in cell2 103. Such communication might be communicated via one System Information Block (SIB) and for UEs 105 in connected mode the communication of cell deactivation time parameter could be done by adding a new parameter on an existing RRC message, e.g. RRCReconfiguration.

Suppose that a UE 105, e.g. UE1 105, that was under 5G cell2 103, is moving towards 5G celll 103 and that after the outage of 5G celll 103 it detects radio signal from a 4G cell 103, e.g. 4G celll 103. Equipped by the cell deactivation time parameter while being on 5G cell2 103, the method comprises a new UE behavior when UE1 105 detects radio signal from 4G celll 103 after 5G celll outage. Such behavior is described as follows and it differs based on whether UE1 105 is in idle mode, or inactive mode or in connected mode.

Step 300-1 : This may be a substep of step 300. UE1 105 is in idle mode or inactive state.

When UE1 105 moving towards the area of 5G celll 103 detects radio signal from 4G celll 103 it will then execute the following actions:

In prior art, UE1 105 triggers a signaling procedure on 4G celll 103, e.g., location update procedure, then when outage is ceased on 5G celll 103, that is after cell deactivation time parameter expiry, UE1 105 will detect again radio coverage from 5G celll 103 and triggers a new location update procedure on 5G celll 103.

HOWEVER, in the present disclosure, thanks to providing UE1 105 with cell deactivation time parameter while it was on 5G cell2 103, then when it detects 4G celll 103, after 5G celll outage, UE1 105 will execute a new UEjorocedure for UE 105 in idle mode or inactive mode that is: It will camp on 4G celll 103 but not perform any radio signaling procedure on 4G celll 103, e.g. e.g. it will not trigger a location update procedure as in prior art. RATHER it will wait until the expiry of cell deactivation time parameter so that the outage on 5G cell 1 103 is ceased and THEN it will camp on 5G cell1 103.

A benefit of Step 300-1 may be that the UE1 105 has spared, in comparison to prior art, two signaling procedures: A first location update procedure on 4G celH 103 when it has detected radio coverage from 4G celH 103 and a second location update procedure on 5G celH 103 after the outage on 5G cell 1 103 is ceased.

Step 300-2: This may be a substep of step 300. UE1 105 is in connected mode.

If UE1 105 is in connected mode,

In prior art, when UE1 105 detects 4G celH 103 and camps on it, it will be able to make a new call setup on 4G celH 103. However the communication that was running on 5G cell2 103 is lost.

HOWEVER, in the present disclosure, thanks to providing UE1 105 with the cell deactivation time parameter while it was on 5G cell2 103, then when it detects 4G celH 103, after 5G celH outage, UE1 105 will execute a new UEjorocedure for UE 105 in connected mode that is: It will camp on 4G cell 1 103 but not perform any radio signaling procedure on 4G cell 1 103, e.g. e.g. it will not trigger a new call setup as in prior art. RATHER it will wait until the expiry of cell deactivation time parameter so that the outage on 5G celH 103 is ceased and THEN it will reestablish its call on 5G celH 103.

Advantages of Step 300-2: In prior art the call that was running on 5G cell2 is released once UE1 camps on 4G celH . However by applying Action 2, the UE1 105 could recover its released communication on 5G celH 103.

Step 310: The list of cell identities of cells surrounding 5G celH 103 are also communicated to the UEs 105 together with the value of the cell deactivation time parameter. The cell identity may be for example PCI, New Radio (NR) Cell Global Identity, or Public Land Mobile Network identifier (PLMN-ld) or a 36bit NR cell identity (NCI).

A list of cell identities is communicated to neighbor cells 103 of cell 1 103 and then to their UEs105. Before the execution of 5G celH outage, the neighbor cells 103 of 5G cell 1 103, e.g. 5G cell2 103 will broadcast, to the UEs 105 being served by these cells 103, two types of info:

Information 1 ): The value of cell deactivation time parameter.

Information 2): The list of cell identities of the 4G cells that are most likely to cover the area_cell1 , e.g., PCI1 1 of 4G cell 1 103.

The difference between this step 310 and previous step may be one or more of the following:

In Step 300 only the value of cell deactivation time parameter is communicated to the UEs 105.

In this Step 310, in addition to the cell deactivation time parameter, a list of cell identities of potential cells 103 that will be covering the area of 5G celU 103 after its outage is also communicated to the UEs 105. This is done in order to avoid a problem, denoted problem wrong neigbor cell and described below.

For simplicity of description and in order to make relevant the following scenario of cells and UEs 105 is illustrated in fig. 4 as follows:

On the left hand of 5G cell2 103 there are two cells 5G celU 103 and on top of it, an overlayer cell, a 4G celU 103 whereas on the right hand of 5G cell2 103 there is no 5G radio coverage rather there are two cells a 4G cell3 103 and a 2G cell2 103.

Suppose that two UEs 105 in idle mode or inactive mode, UE1 105 and UE2 105 are being served by 5G cell2 103 as follows: o before 5G celU outage, UE1 105 is moving towards the left side while UE2 105 is moving in the opposite direction that is towards the right side.

Fig. 4 illustrates a scenario before 5G celU outage. In fig. 4, one area is covered by three 5G cells 103 as a first layer and another three 4G cells 103 as an additional layer. Areal is covered by six cells 103, two of them running on 5G. The part above the horizontal dotted line represents layer 4G covering area, and the part above the horizontal dotted line represents layer 5G covering area 1 .

Description of problem_wrong_neigbor_cell

If UE2 105 was given the cell deactivation time parameter without the list of potential cell identities, then when UE2 105 reaches 4G cell3 103non the right side of 5G cell2 103 if it applies (new UE behavior) THEN this will be an inefficient procedure. In fact, waiting for cell deactivation time parameter under 4G cell3 area will not change anything because in that area UE2 105 will never detect 5G cell 1 radio coverage but rather it will always be getting radio coverage from 4G cell3 103 before and after the planned outage on 5G celH 103.

In order to overcome the problem wrong neigbor cell the following procedure may be used:

Before the execution of 5G celH outage, the neighbor cells of 5G celH 103, e.g. 5G cell2 103 will broadcast two types of info: o Information 1 ): That comprises the value of the cell deactivation time parameter, o Information 2) The list of cell identities of the 4G cells 103 that are most likely to cover the areal , will be also communicated to all UEs 105 on 5G cell2 103. In this example, as shown in fig. 9 below, we suppose that only one 4G cell 103, that is 4G celH 103 with cell identity 11 , e.g. PCI1 1 , will cover the area that was covered by 5G celH 103 before cell 1 outage.

Fig. 5 illustrates a scenario after cell 1 outage. It illustrates that a 4G cell 103 with cell identity 1 1 , e.g. PCI11 , will be covering the area of 5G cell 1 103 after the outage on 5G celH 103 is executed.

Now returning to fig. 3.

Step 320:

The UEs 105 reactions after receiving cell deactivation time parameter and the list of cell identities.

If the UE 105, in idle, inactive or in connected modem, detects a 4G cell 103, e.g. 4G cell 1 103 with cell identity = cell identity 11 , e.g. PCI = PCI1 1 , as in the broadcasted, i.e. information 2, the UE 105 will execute a new UE procedure that is: Camping on 4G celH 103 but not performing, as in prior art, any radio signaling procedure e.g. a location update procedure, RATHER it will wait until the expiry of cell deactivation time parameter so that the outage on 5G cell 1 103 is ceased and THEN it will reconnect to 5G cell 1 103. Otherwise, if the UE 105 detects any 4G cell 103, e.g. 4G cell3 103, with cell identity that is different than the cell identity broadcasted in information 2, THEN prior art method applies, that is it will camp on 4G cell3 103 and triggers immediately a signaling procedure, e.g. a location update procedure or new call setup

The UE1 105 and UE2 105 reaction, whether they are in idle, inactive or in connected mode, based on new UE behavior may be as follows:

For UE1 105, when it detects a 4G cell 103 with cell identity equal to cell identity 11 , e.g. PCI=PCI11 , as in broadcasted information 2, UE1 103 will execute (new UEjorocedure), described above in steps 300-1 & 300-2, that is it will not perform any radio signaling procedure on 4G celU 103, e.g. it will not trigger a location update procedure on 4G celU 103. RATHER it will wait until the expiry of the cell deactivation time parameter so that the outage on 5G celU 103 is ceased and THEN it will resume on 5G cell1.

For UE2 105 in idle or inactive mode as it detects a 4G cell 103 with cell identity = cell identity 33, e.g. PCI = PCI33, which is not equal to the cell identity broadcasted in information 2, THEN prior art method applies, that is UE2 105 will camp on 4G cell3 103 and will trigger immediately, without waiting, any requested signaling procedure, e.g. triggering a location update procedure on 4G cell3 103.

Step 330:

Not necessary all UEs 105 that have received the list of potential cell identities and the cell deactivation time parameter will be triggering the new UE procedure but some particular UEs 105 depending on some factors, e.g. UE mobility prediction and UE traffic prediction.

In order to limit the need for all UEs 105 to receive the value of outage for neighboring cells, only some UEs 105 when they meet some conditions will execute the new UE procedure. Following are some examples of conditions: UE high mobility: In one example, a highly mobile UE 105 might highly benefit from such information since it is more likely to be in coverage of the outage cell in a future tie instance.

UE mobility prediction: With use cases such as connected cars and drones, or UEs 105 moving on trains/metro, the expected future location of a UE 105 is more deterministic in comparison to for example pedestrian movement. The future location of a UE 105 could also be signaled, for example the drone trajectory report specified in 3GPP. Also, vehicles could signal its trajectory using similar type of reporting. Based on the geo-location trajectory of the UE 105, the network node 101 can use deployment information to estimate the UE serving cell in a future time instance.

In case the UE 105 is to be predicted to be in vicinity of an outage cell, the network node 101 can indicate such outage information.

UE traffic prediction: The decision whether the UE 105 to receive an outage period T of a neighboring cell can be based on detailed information on traffic prediction. In case the UE 105 is to be predicted to have data transmission/reception at time of an outage cell, the network node 101 can indicate such outage information.

Action 3: Communicating the period of outage in neighboring cells to UEs 105 that supports call on neighbor cell 103 of RAT1 but does not support call on the new cell 103 of RAT2 that has covered the area of outage

The following applied for action 2 described above and illustrated in fig. 3: whatever is UE mode: idle mode, inactive state or in connected mode, AND whatever is the type of call.

However, the following may apply for action 3, only for UE 105 in connected mode, AND for one type of call. The type of call is about a running application that is not supported on target cell, e.g. the UE 105 is running a particular application that works on 5G but not on 4G. in this document such application is denoted application_only_5G. Fig. 6 is a flow chart illustrating action 3. The method may be performed by the first network node 101 and/or the second network node 101 . The method comprises at least one of the following steps, which steps may be performed in any suitable order than described below.

Initial state:

5G celH 103 will go into an outage, as shown in fig. 7. 4G celH 103 will cover the area of 5G celH 103 after it went down. All cells 103 that are neighbors of celll 103, including 5G cell2 103, will receive the value of the estimated period of outage of celll 103, cell deactivation time parameter.

An outage is planned at time t1 on celll 103 that covers one geographical area, denoted areal . The value of the estimated period of outage of one cell, e.g. 5G celll 103, cell deactivation time parameter, is known. All neighbors of celll 103, e.g. 5G cell2 103, will receive cell deactivation time parameter, via new XnAP or F1 AP procedures.

Now returning to fig. 6.

Step 600:

On each neighbor cell 103, e.g., on 5G cell2 103, the communication of the cell deactivation time parameter is done only for UEs 105 that verifies the following below two conditions:

1 ) UEs 105 that are running an application that works on 5G serving, e.g. 5G cell 1 103 but not on 4G, e.g. a neighbour 4G cell 2 103. Denoted here as application_only_5G.

2) UEs 105 are moving towards the area of 5G celll 103. Two novel procedures, as described in next Step 610, are proposed in order to let the UE 105 guess whether it is moving towards areal or not.

Step 610:

Two procedures may be used by 5G cell2 103 to know whether the UE 105 is moving towards the area of 5G celll 103 or not.

In order to let the network knows whether the UE 105 is moving towards the area of 5G celll 103 or not, the following two procedures are proposed: Procedure 1 : Based on a radio coverage map: A new software entity, e.g. denoted entity 1 , and implemented on the radio side, e.g. on OSS, has the role to keep updated a radio coverage map that is made of all cells 103 in the communications system 100. In particular in this scenario after a cell outage, e.g. 5G celH 103, an algorithm will look only at the cell identity of all cells 103 that covers the area of the cell 103 that went into outage. In the example of fig. 7 above, when 5G celH 103 goes down then 4G celH 103, e.g. with cell identity=11 and 5G cell2 103 will be covering the area of 5G cell1 103. A table, e.g. table 1 , about neighboring cells 103, will be communicated to each cell 103 in the communications system 100 as follows: if a neighbor cellX 103 with cell identity x of RATx is down, then cell identity y and/or cell identity z of RATx or RATy will be covering the area of that cellx 103.

Going back to step 620-2 (New procedure) described in the previous step, when 5G cell2 103 receives a RRC MeasurementReport for an inter RAT handover, for a call that could run only on 5G, it looks at the cell identity value in that MeasurementReport that is the one for which the UE 105 is triggering a handover. Then 5G cell2 103 will consult the received table provided by entity 1 and compares it with cell identity = 11 of 4G celH 103, if they are equal then 5G cell2 103 will conclude that the UE 105 is moving towards 5G cell 1 103 otherwise the UE 105 is not moving towards the area of 5G cel 11 103.

Note that tablel is updated by entity 1 each time a new cell in the area is added and/or the antennas of neighboring cells 103 have been adjusted, e.g. antennas were uptilted or downtilted.

A radio coverage map is composed from all cells 103 in the communications system 100. When a cell 103 goes down, e.g. 5G cell 1 103, a new tool, e.g. on OSS, consists of collecting from that radio coverage map the cell identity of all cells 103 that cover areal of cell1 and send that list of cell identities to neighbors of cell 1 103.

Procedure 2: In real time: When 5G celH 103, goes down, UEs 105 that are in connected mode in 5G cell 1 103 will have their call connection being released by cell1 103. From the UE side it will experience a Radio Link Failure (RLF) and it will go into an idle mode or inactive mode. Based on specification 38.331 , the UE 105 will store RLF information, e.g. cell identity, geographical location where the RLF has occurred and others into a log called rlf-Report. When the UE 105 tries to make a call reestablishment on any cell of same RAT as 5G cell 1 103, e.g. on 5G cell2 103, or any signaling connection, e.g. new call setup, on any cell of different RAT than 5G celll 103, e.g. 4G celll 103, then that stored log rlf-Report might be collected by the network. In particular it is received by the cell 103 and then forwarded to the OSS.

In one example, the rlf-report of all the UEs 105 that were in connected mode are collected at the OSS and a software algorithm, e.g. denoted algorithml , will look at all the rlf-Report that were received at the time of 5G celll outage, and deduce from them to which neighboring cell(s) 103 the UEs 105 that were disconnected from 5G celll 103 has connected to. In the example of fig. 3, some UEs 105 might have triggered a call reestablishment on 5G cell2 103 whereas other UEs 105 might have triggered a new call setup on 4G celll 103. In that way algorithml could detect in real time all the identity, hence the cell identity, of all the potential cells 103 that could be covering the area of 5G celll 103 after its outage.

A tool, e.g. at OSS, looks in all rlfreport sent to the network by any UE 105 that has experienced a handover or a call failure. Based on the rlfreport that contains the identity of the cell 103 where the failure occurred, 5G celll 103 in this example, and based on the identity of the cell 103 where the UE 105 has reported its rlfreport, cell2 103 in this example, the tool could get the cell identity of cells 103 covering celll 103.

Step 620:

Procedure for communicating the value of the cell deactivation time parameter only for UEs 105 in connected mode and they are running an application that works on serving cell 103 but not on the neighboring cell 103. Such procedure might be illustrated with the below steps:

1 ) After the outage occurs on 5G celll 103 and while the UE 105 is running a particular call, application_only_5G, and while it is moving away from 5G cell2 103, based on the scenario shown in fig. 3, at a certain point the UE 105 will have to trigger an inter RAT handover, e.g. in this example, from 5G cell 103 towards a 4G cell 103, as in both sides of 5G cell2 103 a 4G cell 103 is located.

2) By looking at the cell identity of the target cell 103 that is sent in RRC MeasurementReport carrying the inter RAT handover event, the network, in particular 5G cell2 103, checks, as described in step 620, whether the UE 105 is moving towards the area of outage that is towards 4G celll 103, or towards another area, e.g. towards 4G cell3 103. Then one of the following two procedures is executed: Step 620-1 (Prior art procedure): If the UE 105, e.g. UE2 105, is NOT moving towards the area of 5G cell1 103, e.g. towards 4G cell3 103 in this example, then the value of cell deactivation time parameter is NOT communicated from 5G cell2 103 to UE2 105and prior art procedure is executed as follows: The inter-RAT handover is rejected by 4G cell3 103 and as UE2 105 continues moving deeper inside 4G cell3 103 then at a certain point it will lose its radio connection from 5G cell2 103 and as a consequence the application_only_5G call is dropped and UE2 105 will be camping in idle mode or inactive mode on 4G cell2 103 and as it could not run application_only_5G call on 4G cell3 103 it could establish only a new call that applies on 4G.

Step 620-2 (New procedure): If the UE 105, e.g., UE1 105, is moving towards the area of 5G celU 103, that is towards 4G celU 103 in this example, then the value of cell deactivation time parameter is communicated from the network node 101 in 5G cell2 103 to UE1 105 and the following actions are executed: o The inter-RAT handover is rejected by 4G celU 103 as application_only_5G call is not supported on a 4G cell 103. As UE1 105 continues moving deeper inside 4G celU 103 then at a certain point it will lose its radio connection from 5G cell2 103 and as a consequence the call is dropped and UE1 105 will be camping in idle mode or inactive mode on 4G celU . HOWEVER unlike the case of prior art described above in step 620-1 , UE1 105 will execute a new UE procedure as follows:

■ After UE1 105 camps on 4G celU 103 it does not perform any radio signaling procedure on 4G celU 103, e.g. e.g. it will not attach to 4G network nor trigger a new call setup as in prior art. RATHER it will wait until the expiry of cell deactivation time parameter so that the outage on 5G celU 103 is ceased and THEN it will reestablish its call on 5G celU 103.

When cell2 103 receives a RRC MeasurementReport to trigger a handover from cell2 103 towards any neighboring cell 103, cell2 algorithm will look at the cell identity in MeasurementReport & compares this cell identity with the list of cell identities of cells 103 covering celU 103. If the cell identity is not included: the UE 105 is NOT moving towards areal & prior art procedures are used and as a consequence, the call is released because the running application on UE 105 does not work on 4G

If the cell identity is included -> the UE 105 is moving towards areal & new UE procedure is executed as follows: o After UE1 105 camps on cell2 103 it does not perform any radio signaling procedure on cell2 103. RATHER it will wait until the expiry of cell deactivation time parameter and THEN the UE 150 will reestablish its call on celH 103.

Action 3-1 : The cell deactivation time parameter is not communicated to the UE 105 by the cell 103 rather it may be hardcoded in the UE 105

Fig. 8 is a flow chart illustrating action 3-1 . The method may be performed by the first network node 101 and/or the second network node 101 and/or the UE 105. The method comprises at least one of the following steps, which steps may be performed in any suitable order than described below.

With action 3 described in previous section, the cell deactivation time parameter is communicated from the network node 101 in the cell 103 to the UE 105 via dedicated signaling message. An alternative method comprises hardcoding one value of cell deactivation time parameter, e.g. 2 seconds, on its software. Action 3-1 could be composed of the following two steps:

Initial state:

5G celH 103 will go into an outage and as shown in fig. 7 and 4G celH 103 will cover the area of 5G cell1 103 after it went down.

The value of cell deactivation time parameter may be hardcoded in the UE 105.

The list of cell identities of the 4G cells 103 that are most likely to cover the areal , will be also communicated to all neighbors of 5G celH 103, e.g. including 5G cell2 103.

A new parameter, e.g. denoted use_hardcoded_cell_deactivation_time_parameter and coded into 1 bit, is added to the RRC protocol. If the value is 1 then the UE 105 will use the hardcoded value of cell deactivation time parameter otherwise, i.e. when value = 0, it will not use it.

The UE 105 is running an application that works on a 5G cell 103 but not on a 4G cell 103.

Step 800:

UE behaviour after celU outage is executed and when the UE 105 is moving from 5G cell2 103 towards a 4G cell 103. UE reaction while moving, after 5G celU outage, from 5G cell2 103 towards a 4G cell 103.

If the UE 105, e.g. UE1 105, is running a particular call, application_only_5G, that works on 5G but not on 4G, then the procedure will vary depending on which direction UE1 105 is moving and which could be summarize in the following two scenarios:

Scenario 1 : UE1 105 is moving from 5G cell2 103 towards the area of 5G celU 103, that is towards 4G celU 103 in this example, then the following actions are executed:

- At a certain point, an inter-RAT handover is triggered by UE1 105 by sending a RRC MeasurementReport, containing a radio measurement event, to 5G cell2 103 and in this example it comprises the cell identity of 4G celU . Based on prior art procedures, as in this example the call is not supported on 4G celU 103, the inter RAT handover is rejected. Herein, 5G cell2 103 will look at target PCI and as it is in list of cell identities that will cover 5G celU 103 after celU outage, the value of the new parameter use_hardcoded_cell_deactivation_time_parameter is set to 1 and it is sent to UE1 105.

- As UE1 105 continues moving deeper inside 4G celU 103 then at a certain point it will lose its radio connection from 5G cell2 103 and as a consequence the call is dropped and UE1 103 will be camping in idle mode or inactive mode on 4G celU . HOWEVER unlike the case of prior art described above where UE1 105 release the 5G call and triggers new signaling on 4G celU 103, here a new procedure is triggered by UE1 105 as follows: o After UE1 105 camps on 4G celU 103 it does not perform any radio signaling procedure on 4G celU 103, e.g. it will not trigger a location update procedure etc... . RATHER it will wait until the expiry of cell deactivation time parameter so that the outage on 5G celU 103 is ceased and THEN it will re-establish its call on 5G celU 103. Scenario 2: UE1 105 is NOT moving towards the area of 5G celH 103, that is UE1 105 is moving towards 4G cell3 103 in this example, then the follow actions are executed:

The inter-RAT handover is rejected by 4G cell3 103 as application_only_5G call is not supported on a 4G cell 103 AND an indication via the new parameter use_hardcoded_cell_deactivation_time_parameter = 0 is sent to the UE 105 in order NOT to use cell deactivation time parameter when it detects radio coverage from a 4G cell 103.

As UE1 105 continues moving deeper inside 4G cell3 103 then at a certain point it will lose its radio connection from 5G cell2 103 and as a consequence the call is dropped and UE1 105 go to idle mode or inactive mode. It will then follow prior art procedures, which is the UE1 105 camps on 4G cell3 103 and triggers immediately on that 4G cell 103 the prior art signaling procedures, e.g. location update procedure, attach procedure, a new call setup etc.

During the inter-RAT handover procedure from 5G cell2 103 towards a neighboring 4G cell 103, the UE will report in RRC MeasurementReport the cell identity of target 4G cell 103.

5G cell2 algorithm compares the received cell identity with the list of cell identities of cells 103 covering celU 103.

If the cell identity is not included: the UE 105 is NOT moving towards areal and prior art procedures are used. As a consequence, the call is released because the running application on UE 105 does not work on 4G.

If the cell identity is included: the UE 105 is moving towards areal . THEN 5G cell2 103 will set use_hardcoded_cell_deactivation_time_parameter = 1 and a new UE procedure is executed by the UE 105 as follows:

After UE1 105 camps on 4G celU it does not perform any radio signaling procedure on 4G celU . RATHER it will wait until the expiry of cell deactivation time parameter and THEN the UE 105 will re-establish its call on 5G celU 103.

The method for handling cell deactivation will now be described with reference to the flowchart depicted in fig. 9. The method is performed by the UE 105. Prior to the first step in fig. 9, the first network node 101 may have provided the cell deactivation time parameter to the second network node 101 . The cell deactivation time parameter may have been determined by the first network node 101 . At the start of the method, the UE 105 is currently served by the second network node 101 , e.g., 5G cell 2 103.

In fig. 9, the following examples are used:

Cell 1 103: 5G cell 1 103

Cell 2 103: 5G cell 2 103

Cell 3 103: 4G cell 3 103

Note that the above is only an example, and that any other suitable RAT technologies, number of and type of cells 103 are equally applicable.

The method comprises the following steps, which steps may as well be carried out in another suitable order than described below.

Step 901

This step corresponds to step 310 in fig. 3. The UE 105 obtains the cell deactivation time parameter and a list of cell identities of cells that may cover area of cell 1 103. The cell deactivation time parameter may be obtained by receiving it from the network node 101 currently serving the UE 103, e.g. second network node 101 , or by being hardcoded in the UE 105 at some earlier time instance.

Step 902

This step corresponds to step 320 and step 303 in fig. 3. The UE 105 moves away from cell 2 103, e.g. a 5G cell2 103, and detects, e.g. receives, at least one signal from cell 3 103, e.g. a 4G cell 3 103. The signal from cell 3 103 may comprise a cell identity of cell 3 103 or information indicating the cell identity of cell 3 103, or the cell identity of cell 3 103 may be derivable from the signal from cell 3 103.

Step 903

This step corresponds to step 320 and step 330 in fig. 3. The UE 105 checks if the cell identity of cell 3 103 is the same as in the cell identity list from step 901 . If the cell identity of cell 3 is the same as in the cell identity list, as indicated with yes in fig. 9, then the method proceeds to step 906. If the cell identity of cell 3 103 is not the same as in the cell identity list, as indicated with no in fig. 9, then the method proceeds to step 904. When the cell identity of cell 3 103 is the same as in the cell identity list it is an indication of that the UE 105 moves towards an area covered by cell 1 103. When the cell identity of cell 3 103 is not the same as in the cell identity list, it is an indication of that the UE 105 does not move towards an area covered by cell 1 103.

Step 904

This step corresponds to steps 320 and 330 in fig. 3, steps 600, 610, 620 in fig. 6 and step 800 in fig. 8. This step is performed when the cell identity of cell 3 103 is not the same as in the cell identity list, i.e. the UE 105 does not move towards an area covered by cell 1 . The UE 105 determines to camp on cell 3 103, e.g. the 4G cell 3 103.

Step 905

This step corresponds to steps 320 and 330 in fig. 3, steps 600, 610, 620 in fig. 6 and step 800 in fig. 8. When the UE 105 has determined to camp on cell3 103, it performs a prior art signaling procedure, e.g., an attach procedure. Using other words, the UE 105 establishes the communication connection, e.g. the communication with a network node 101.

Step 906

This step corresponds to steps 320 and 330 in fig. 3, steps 600, 610, 620 in fig. 6 and step 800 in fig. 8. The UE 105 determines if it is in connected mode and runs a particular application. If the UE 105 is both in connected mode and also runs a particular application, as indicated with yes in fig. 9, the method proceeds to step 910. If the UE 105 is not both in connected mode and also runs a particular application, as indicated with no in fig. 9, the method proceeds to step 907.

Step 907

This step corresponds to steps 320 and 330 in fig. 3, steps 600, 610, 620 in fig. 6 and step 800 in fig. 8. This step is performed when the UE 105 is not both in connected mode and also runs a particular application. The UE 105 determines to camp on cell 3 103 without performing a prior at signaling procedure, e.g. an attach procedure.

After step 907 has at least partly been performed, the UE 105 does not remain on cell3 103 being camped without performing any signaling procedure. It will wait for the cell deactivation time parameter to expire and then return camping on celH 103. The UE 105 does not need to perform any signaling procedure on celH 103 as it was already registered there.

Step 908

This step corresponds to steps 320 and 330 in fig. 3, steps 600, 610, 620 in fig. 6 and step 800 in fig. 8. This step is performed after step 907. The UE 105 determines to wait until the cell deactivation time parameter has expired.

Step 909

This step corresponds to steps 320 and 330 in fig. 3, steps 600, 610, 620 in fig. 6 and step 800 in fig. 8. This step is performed after step 908. When the cell deactivation time parameter has expired, the UE 105 detects a signal from cell 1 103, e.g., 5G cell 1 103, and determines to camp on cell 1 103.

Between steps 906 and 909, the UE 105 is moving from second cell 103. The first cell 103 is deactivated then the UE 105 camps on third cell that is covering the first cell 103. It is assumed the UE 105 has totally moved away from second cell 103, i.e. lost the radio coverage from second cell 103, otherwise it could remain on second cell without issue.

Step 910

This step corresponds to steps 320 and 330 in fig. 3, steps 600, 610, 620 in fig. 6 and step 800 in fig. 8. This step is performed when the UE 105 is both in connected mode and also runs a particular application. The UE 105 determines to wait until the cell deactivation time has expired.

Step 911

This step corresponds to steps 320 and 330 in fig. 3, steps 600, 610, 620 in fig. 6 and step 800 in fig. 8. This step is performed after step 910. The UE 105 detects a signal from cell 1 103, e.g. 5G cell 1 103.

912

This step is performed after step 911 . The UE 105 determines to resume running the particular application. The method described above will now be described seen from the perspective of the UE. Fig. 10 is a flowchart describing the present method in the UE 105 for handling cell deactivation in the communications system 100. The UE 105 is currently served by a second network node 101 in a second cell 103. The UE 105 may be idle mode, inactive state or connected mode. The method comprises at least one of the following steps to be performed by the UE 105, which steps may be performed in any suitable order than described below:

Step 1001

This step may correspond to step 310 in fig. 3 and step 901 in fig. 9. The UE 105 obtains a cell deactivation time parameter indicating duration of deactivation of coverage from the first cell 103. The first cell 103 is a neighbor cell to the second cell 103.

The neighbouring cell 103 may have been established via Automatic Neighbor Relation (ANR), neighbouring cells 103 may be in geographic vicinity of each other etc. Note that ANR is a feature of 5G NR that automatically discovers and establishes neighbor relations between cells 103.

The cell deactivation time parameter associated with the first cell 103 may be obtained by receiving it from the network node 101 which broadcasted it, or by being hardcoded in the UE 105 at some earlier time instance.

When the second network node 101 of the second cell 103 has obtained the value of cell deactivation time parameter from first network node 101 of the first cell 103, the second network node 101 may broadcast the value of the cell deactivation time parameter to all UEs 105 in the second cell 103.

Step 1002

This step may correspond to step 310 in fig. 3 and step 901 in fig. 9. The UE 105 obtains cell identity information of other cells 103 that may at least partly cover an area of the first cell 103 when the first cell 103 is deactivated. The cell identify information may be PCI, a list of PCIs, a NR Cell Global Identity, or a PLMN-ld or a 36bit NCI etc. The cell identify information may be obtained from a network node 101 . Step 1003

This step may correspond to steps 320 and 330 in fig. 3 and step 902 in fig. 9. The UE 105 determines that the UE 105 moves away from the second cell 103 and approaches a third cell 103.

Step 1004

This step may correspond to steps 320 and 330 in fig. 3 and step 903 in fig. 9. The UE 105 compares the cell identity of the third cell 103 with the corresponding cell identity in the obtained cell identity information.

Step 1005

This step may correspond to steps 904 and 907 in fig. 9. This step corresponds to steps 904 and 907 in fig. 9. The UE 105 acts according to the result of the comparison.

Based on a result of the comparison, the UE 105 may determine to: camp on the third cell 103 with or without establishing a communication connection with a third network node 101 , e.g. without performing a prior art signaling procedure, or to not monitor paging signals on the third cell 103 until the cell deactivation time has expired, e.g. wait until the cell deactivation time has expired.

The term camping refers herein to an idle mode UE 105 that monitors the paging messages from a network node 101 , e.g. a third network node 101.

Step 1006

This step may correspond to steps 320, 330 in fig. 3, steps 600, 610 and 620 in fig. 6, step 800 in fig. 8 and step 904 in fig. 9. When the result of the comparison in step 1004 indicates in step 1005 that the cell identity of the third cell 103 is not the same as in the obtained cell identity information, then the UE 105 may determine that the UE 105 is not moving towards an area covered by the first cell 103.

Step 1007

This step may correspond to steps 320, 330 in fig. 3, steps 600, 610 and 620 in fig. 6, step 800 in fig. 8 and step 904 in fig. 9. This step may be performed after step 1006. The UE 105 may determine to camp on the third cell 103. Step 1008

This step may correspond to steps 320, 330 in fig. 3, steps 600, 610 and 620 in fig. 6, step 800 in fig. 8 and step 904 in fig. 9. This step may be performed after step 1006. The UE 105 may establish a communication connection, e.g. a communication connection with the third network node 101 . Using other words, the UE 105 may perform the prior art signaling procedure.

Step 1009

This step may correspond to steps 320, 330 in fig. 3, steps 600, 610 and 620 in fig. 6, step 800 in fig. 8 and step 906 in fig. 9. When the result of the comparison in step 1004 indicates in step 1005 that the cell identity of the third cell 103 is the same as in the obtained cell identity information, the UE 105 may determine that the UE 105 is moving towards an area covered by the first cell 103.

Step 1006 described earlier is about when the UE 105 has moved in an area where cell identity is not included in the received list, and the prior art applies where the UE 105 does not wait, whereas step 1009 is when the UE 105 has moved to the area where the cell identity is included in the list. Here the UE 105 does not apply prior art and has to wait for the cell deactivation time parameter to expire in order to return to the first cell after outage is ceased on it.

Step 1010

This step may correspond to steps 320, 330 in fig. 3, steps 600, 610 and 620 in fig. 6, step 800 in fig. 8 and step 906 in fig. 9. This step may be performed after step 1009. The UE 105 may determine whether or not the UE 105 is both in connected mode and runs a predetermined application.

The predetermined application may be an application that works in the second cell 103, but not in the first cell 103.

Step 1011

This step may correspond to steps 320, 330 in fig. 3, steps 600, 610 and 620 in fig. 6, step 800 in fig. 8 and step 907 in fig. 9. When the result of the determining in step 1010 indicates that the UE 105 is not both in connected mode and runs the predetermined application, then the UE 105 may determine to camp on the third cell 103 during the cell deactivation time and without establishing a communication connection, e.g. a communication connection with the third cell 103. In other words, without performing the prior art signaling procedure on the third cell 103.

The term “UE is not both in connected mode and runs the predetermined application” refers to that the UE 105 is not in connected mode AND is not running the predetermined application. The term “UE is not both in connected mode and runs the predetermined application” does not refer to that the UE 105 is not in connected mode or/but is running a predetermined application, because then the UE 105 is in idle mode or inactive mode. If the UE 105 is not in connected mode, it cannot be running any application at all, and consequently it cannot be running the predetermined application.

Step 1012

This step may correspond to steps 320, 330 in fig. 3, steps 600, 610 and 620 in fig. 6, step 800 in fig. 8 and step 908 in fig. 9. This step is performed after step 1011. The UE 105 may determine to camp on the first cell 103 wait until the cell deactivation time has expired.

Step 1013

This step may correspond to steps 320, 330 in fig. 3, steps 600, 610 and 620 in fig. 6, step 800 in fig. 8 and step 909 in fig. 9. This step is performed after step 1012. The UE 105 may detect a signal from the first cell 103 after the cell deactivation time has expired. The signal may comprise of the Primary Synchronization Signal (PSS), where the PSS is a periodic signal that helps the UE 105 to identify the cell's physical layer timing. It may also comprise of Synchronization Signal Block (SSB), which are used for synchronization and initial cell acquisition by UE 105 in NR.

Step 1014

This step may correspond to steps 320, 330 in fig. 3, steps 600, 610 and 620 in fig. 6, step 800 in fig. 8 and step 909 in fig. 9. This step is performed after step 1013. The UE 105 may determine to camp on the first cell 103 when the signal from the first cell 103 has been detected. Step 1015

This step may correspond to steps 320, 330 in fig. 3, steps 600, 610 and 620 in fig. 6, step 800 in fig. 8 and step 909 in fig. 9. When the result of the determining in step 1010 indicates that the UE 105 is both in connected mode and also runs the predetermined application, then the UE 105 may determine to wait on the third cell 103 until the cell deactivation time has expired.

Step 1016

This step may correspond to steps 320, 330 in fig. 3, steps 600, 610 and 620 in fig. 6, step 800 in fig. 8 and step 909 in fig. 9. This step is performed after step 1015. The UE 105 may detect a signal from the first cell 103 after the cell deactivation time has expired.

Step 1017

This step may correspond to steps 320, 330 in fig. 3, steps 600, 610 and 620 in fig. 6, step 800 in fig. 8 and step 911 in fig. 9. This step is performed after step 1016. The UE 105 may determine to resume running the predetermined application when the signal from the first cell has been detected.

The method described above will now be described seen from the perspective of the first network node 101 . Fig. 11 is a flowchart describing the present method in the first network node 101 for handling cell deactivation in the communications system 100. The first network node 101 serves a first cell 103. The method comprises at least one of the following steps to be performed by the first network node 101 , which steps may be performed in any suitable order than described below:

Step 1100

This step corresponds to step 200 in fig. 2. The first network node 101 may determine the cell deactivation time parameter.

The cell deactivation parameter may be determined by one or more of the following:

- in case of a planned cell deactivation, the cell deactivation time parameter is determined in advance of the cell deactivation; and/or - in case of an unplanned cell deactivation, the cell deactivation time parameter is determined based on historic values obtained for the same event(s) causing the cell deactivation; and/or

- in case of an unplanned cell deactivation, the cell deactivation time parameter is determined, e.g. by using and AI/ML algorithm, based on information associated with event(s) and data preceding the cell deactivation and inferring the deactivation time for the cell 103.

Step 1101

This step corresponds to step 210 in fig. 2 and step 901 in fig. 9. The first network node 101 provides, to a second network node 101 , a cell deactivation time parameter indicating duration of deactivation of coverage from a first cell 103. The first cell 103 is a neighbor cell to the second cell 103 served by the second network node 101 .

Recall that the cell deactivation time parameter may be provided from the second network node 101 to the UE 105, or it may be hardcoded in the UE 105. When the cell deactivation time parameter is hardcoded in the UE 105, then steps 1100 and 1101 may not necessarily be performed.

Step 1102

This step corresponds to step 200 in fig. 2. The first network node 101 may determine the cell identify information by one or both of:

- extracting the cell identity information from a radio coverage map that comprises radio coverage of all cells 103 of all technologies at each geographical location of the communications system 100; and/or obtaining the cell identify information from another network node 101 , e.g. tool e.g. at OSS, which looks in all rlfreport sent to the network by any UE 105 that has experienced a handover or a call failure. The other network node 101 may be the first network node 101.

Step 1103

This step corresponds to step 210 in fig. 2, step 310 in fig. 3 and step 901 in fig. 9. The first network node 101 provides, to a second network node 101 , cell identity information of other cells 103 that may at least partly cover an area of the first cell 103 when the first cell 103 is deactivated.

The method described above will now be described seen from the perspective of the first network node. Fig. 12 is a flowchart describing the present method in the second network node 101 for handling cell deactivation in the communications system 100. The second network node 101 serves a second cell 103. The method comprises at least one of the following steps to be performed by the second network node 101 , which steps may be performed in any suitable order than described below:

Step 1201

This step corresponds to step 300 in fig. 3 and 901 in fig. 9. The second network node 101 may obtain, from a first network node 101 , a cell deactivation time parameter indicating duration of deactivation of coverage from a first cell 103. The first cell 103 is a neighbor cell 103 to the second cell 103.

The cell deactivation time parameter obtained from the first network node 101 may be obtained in an IE comprised in an existing message or a new message and obtained from the first network node 101 via a peer to peer interface, or the deactivation time parameter may be obtained from the first network node 101 via a RAN to RAN or RAN internal interface and by using an OSS.

Step 1202

This step corresponds to step 300 in fig. 3 and 901 in fig. 9. The second network node 101 may provide the cell deactivation time parameter to a UE 105.

Recall that the cell deactivation time parameter may be provided from the second network node 101 to the UE 105, or it may be hardcoded in the UE 105. When the cell deactivation time parameter is hardcoded in the UE 105, then steps 1201 and 1202 may not be performed.

Step 1203

This step corresponds to step 310 in fig. 3 and 901 in fig. 9. The second network node 101 obtains, from the first network node 101 , cell identity information of other cells 103 that may at least partly cover an area of the first cell 103 when the first cell 103 is deactivated.

Step 1204

This step corresponds to step 310 in fig. 3 and 901 in fig. 9. The second network node 101 provides the cell identity information to the UE 105.

To perform the method steps shown in fig. 10 for handling cell deactivation in the communications system 100, the UE 105 may comprise an arrangement as shown in fig. 13a and/or fig. 13b. The UE 105 is currently served by a second network node 101 in a second cell 103. The UE 105 may be idle mode, inactive state or connected mode. Fig. 13a and fig. 13b depict two different examples of the arrangement that the UE 105 may comprise. The UE 105 may comprise the following arrangement depicted in fig 13a.

The UE 105 is arranged to, e.g. by means of an obtaining unit 1300, obtain a cell deactivation time parameter indicating duration of deactivation of coverage from a first cell 103. The first cell 103 is a neighbor cell 103 to the second cell 103. The obtaining unit 1300 may also be referred to as an obtaining module unit, an obtaining means, an obtaining circuit, means for obtaining etc. The obtaining unit 1300 may be a processor 1301 of the UE 105 or comprised in the processor 1301 of the UE 105.

The cell deactivation time parameter associated with the first cell may be obtained by receiving it from the network node 101 which broadcasted it, or by being hardcoded in the UE 105 at some earlier time instance.

The UE 105 is arranged to, e.g. by means of the obtaining unit 1301 , obtain cell identity information of other cells 103 that may at least partly cover an area of the first cell 103 when the first cell 103 is deactivated. The cell identify information may be PCI, a list of PCIs, NR Cell Global Identity, PLMN-ld or a 36bit NCI etc. The cell identify information may be obtained from a network node 101 .

The UE 105 is arranged to, e.g. by means of a determining unit 1303, determines that the UE 105 moves away from the second cell 103 and approaches a third cell 103. The determining unit 1303 may also be referred to as a determining module, a determining means, a determining circuit, means for determining etc. The determining unit 1303 may be a processor 1301 of the UE 105 or comprised in the processor 1301 of the UE 105.

The UE 105 is arranged to, e.g. by means of a comparing unit 1305, compares the cell identity of the third cell 103 with the corresponding cell identity in the obtained cell identity information. The comparing unit 1305 may also be referred to as a comparing module, a comparing means, a comparing circuit, means for comparing etc. The comparing unit 1305 may be a processor 1301 of the UE 105 or comprised in the processor 1301 of the UE 105.

The UE 105 may be arranged to, e.g. by means of the determining unit 1303, based on a result of the comparison, determine to camp on the third cell 103 with or without performing a prior art signaling procedure, or to wait until the cell deactivation time has expired.

The UE 105 may be arranged to, e.g. by means of the determining unit 1303, when the result of the comparison in step 1004 indicates in step 1005 that the cell identity of the third cell 103 is not the same as in the obtained cell identity information, then the UE 105 may be arranged to determine that the UE 105 is not moving towards an area covered by the first cell 103.

The UE 105 may be arranged to, e.g. by means of the determining unit 1303, determine to camp on the third cell 103.

The UE 105 may be arranged to, e.g. by means of a performing unit 1308, perform the prior art signaling procedure. The performing unit 1308 may also be referred to as a performing module, a performing means, a performing circuit, means for performing etc. The performing unit 1308 may be a processor 1301 of the UE 105 or comprised in the processor 1301 of the UE 105. The UE 105 may be arranged to, e.g. by means of the determining unit 1303, when the result of the comparison in step 1004 indicates in step 1005 that the cell identity of the third cell 103 is the same as in the obtained cell identity information, the UE 105 may be arranged to determine that the UE 105 is moving towards an area covered by the first cell 103.

The UE 105 may be arranged to, e.g. by means of the determining unit 1303, determine whether or not the UE 105 is both in connected mode and runs a predetermined application. The predetermined application may be an application that works in the second cell, but not in the first cell 103.

The UE 105 may be arranged to, e.g. by means of the determining unit 1303, when the result of the determining in step 1009 indicates that the UE 105 is not both in connected mode and runs the predetermined application, then the UE 105 may be arranged to determine to camp on the third cell 103 during the cell deactivation time and without performing the prior art signaling procedure on the third cell 103.

The UE 105 may be arranged to, e.g. by means of the determining unit 1303, determine to wait until the cell deactivation time has expired.

The UE 105 may be arranged to, e.g. by means of a detecting unit 1310, detect a signal from the first cell 103 after the cell deactivation time has expired. The detecting unit 1310 may also be referred to as a detecting module, a detecting means, a detecting circuit, means for detecting etc. The detecting unit 1310 may be a processor 1301 of the UE 105 or comprised in the processor 1301 of the UE 105.

The UE 105 may be arranged to, e.g. by means of the determining unit 1303, determine to camp on the first cell 103 when the signal from the first cell 103 has been detected.

The UE 105 may be arranged to, e.g. by means of the determining unit 1303, when the result of the determining in step 1009 indicates that the UE 105 is both in connected mode and also runs the predetermined application, then the UE 105 may be arranged to determine to wait on the third cell 103 until the cell deactivation time has expired. The UE 105 may be arranged to, e.g. by means of the detecting unit 1303, detect a signal from the first cell after the cell deactivation time has expired.

The UE 105 may be arranged to, e.g. by means of the determining unit 1303, determine to resume running the predetermined application when the signal from the first cell 103 has been detected.

The present disclosure related to the UE 105 may be implemented through one or more processors, such as a processor 1301 in the UE 105 depicted in fig. 13a, together with computer program code for performing the functions and actions described herein. A processor, as used herein, may be understood to be a hardware component. The program code mentioned above may also be provided as a computer program product, for instance in the form of a data carrier carrying computer program code for performing the present disclosure when being loaded into the UE 105. One such carrier may be in the form of a CD ROM disc. It is however feasible with other data carriers such as a memory stick. The computer program code may be provided as pure program code on a server and downloaded to the UE 105.

The UE 105 may comprise a memory 1315 comprising one or more memory units. The memory 1315 is arranged to be used to store obtained information, store data, configurations, schedulings, and applications etc. to perform the methods herein when being executed in the UE 105.

The UE 105 may receive information from, e.g. the network node 101 , through a receiving port 1320. The receiving port 1320 may be, for example, connected to one or more antennas in UE 105. The UE 105 may receive information from another structure in the communications system 100 through the receiving port 1320. Since the receiving port 1320 may be in communication with the processor 1301 , the receiving port 1320 may then send the received information to the processor 1301 . The receiving port 1320 may also be configured to receive other information.

The processor 1301 in the UE 105 may be configured to transmit or send information to e.g. network node 101 or another structure in the communications system 100, through a sending port 1323, which may be in communication with the processor 1301 , and the memory 1315.

The UE 105 may comprise the obtaining unit 1300, the determining unit 1303, the comparing unit 1305, the performing unit 1308, the detecting unit 1310 and other unit(s) 1313.

Those skilled in the art will also appreciate that the obtaining unit 1300, the determining unit 1303, the comparing unit 1305, the performing unit 1308, the detecting unit 1310 and other unit(s) 1313 described above may refer to a combination of analogue and digital circuits, and/or one or more processors configured with software and/or firmware, e.g., stored in memory, that, when executed by the one or more processors such as the processor 1001 , perform as described above. One or more of these processors, as well as the other digital hardware, may be comprised in a single Application-Specific Integrated Circuit (ASIC), or several processors and various digital hardware may be distributed among several separate components, whether individually packaged or assembled into a System-on-a-Chip (SoC).

The different units described above may be implemented as one or more applications running on one or more processors such as the processor 1301 .

Thus, the methods described herein for the UE 105 may be respectively implemented by means of a computer program 1325 product, comprising instructions, i.e., software code portions, which, when executed on at least one processor 1301 , cause the at least one processor 1301 to carry out the actions described herein, as performed by the UE 105. The computer program 1325 product may be stored on a computer-readable storage medium 1328. The computer-readable storage medium 1013, having stored thereon the computer program 1325, may comprise instructions which, when executed on at least one processor 1301 , cause the at least one processor 1301 to carry out the actions described herein, as performed by the UE 105. The computer-readable storage medium 1013 may be a non-transitory computer-readable storage medium, such as a CD ROM disc, or a memory stick. The computer program 1325 product may be stored on a carrier containing the computer program 1325 just described, wherein the carrier is one of an electronic signal, optical signal, radio signal, or the computer-readable storage medium, as described above.

The UE 105 may comprise a communication interface configured to facilitate communications between the UE 105 and other nodes or devices, e.g., the network node 101 , or another structure. The interface may comprise a transceiver configured to transmit and receive radio signals over an air interface in accordance with a suitable standard.

The UE 105 may comprise the following arrangement depicted in fig. 13b. The UE 105 may comprise a processing circuitry 1330, e.g., one or more processors such as the processor 1301 , in the UE 105 and the memory 1315. The UE 105 may also comprise a radio circuitry 1333, which may comprise e.g., the receiving port 1320 and the sending port 1323. The processing circuitry 1330 may be configured to, or operable to, perform the method actions according to fig. 2-fig.12 in a similar manner as that described in relation to fig. 13a. The radio circuitry 1333 may be configured to set up and maintain at least a wireless connection with the UE 105. Circuitry may be understood herein as a hardware component.

Hence, the present disclosure also relates to the UE 105 operative to operate in the communications system 100. The UE 105 may comprise the processing circuitry 1101 and the memory 1315. The memory 1315 comprises instructions executable by said processing circuitry 1301 . The UE 105 is operative to perform the actions described herein in relation to the UE 105, e.g., in figs. 2-12.

Figs. 14a and fig. 14b depict two different examples in panels a) and b), respectively, of the arrangement that the network node 101 may comprise. The network node 101 may comprise the following arrangement depicted in fig. 14a. The network node 101 may be the first network node or the second network node, or any other network node in the communications system 100. The first network node 101 serves a first cell 103 and the second network node 101 serves a second cell 103.

The first network node 101 may be arranged to, e.g., by means of a determining unit 1400, determine the cell deactivation time parameter. The cell deactivation parameter may be determined by one or more of the following: in case of a planned cell deactivation, the cell deactivation time parameter is determined in advance of the cell deactivation; and/or in case of an unplanned cell deactivation, the cell deactivation time parameter is determined based on historic values obtained for the same event(s) causing the cell deactivation; and/or in case of an unplanned cell deactivation, the cell deactivation time parameter is determined, e.g. by using and AI/ML algorithm, based on information associated with event(s) and data preceding the cell deactivation and inferring the deactivation time for the cell.

The determining unit 1400 may also be referred to as a determining module, a determining means, a determining circuit, means for determining etc. The determining unit 1400 may be a processor 1401 of the network node 101 or comprised in the processor 1401 of the network node 101 .

The first network node 101 may be arranged to, e.g., by means of a providing unit 1403, provide, to a second network node 101 , a cell deactivation time parameter indicating duration of deactivation of coverage from a first cell 103. The first cell 103 is a neighbor cell 103 to the second cell 103. The providing unit 1403 may also be referred to as a providing module, a providing means, a providing circuit, means for providing etc. The providing unit 1403 may be a processor 1401 of the network node 101 or comprised in the processor 1401 of the network node 101 . The providing unit 1403 may be a transmitter, a transceiver or sending port of the first network node 101 .

The first network node 101 may be arranged to, e.g., by means the determining module 1400, determine the cell identify information by one or both of:

- extracting the information from a radio coverage map that comprises radio coverage of all cells 103 of all technologies at each geographical location of the network 100; and/or

- obtaining the cell identify information from another node, e.g. tool, e.g. at OSS, which looks in all rlfreport sent to the network by any UE 105 that has experienced a handover or a call failure.

The first network node 101 may be arranged to, e.g. by means of the providing unit

1403, provide to a second network node 101 , cell identity information of other cells 103 that may at least partly cover an area of the first cell 103 when the first cell 103 is deactivated.

The second network node 101 may be arranged to, e.g. by means of an obtaining unit 1405, obtain, from a first network node 101 , a cell deactivation time parameter indicating duration of deactivation of coverage from a first cell 103. The first cell 103 is a neighbor cell to the second cell 103. The obtaining unit 1405 may also be referred to as an obtaining module, an obtaining means, an obtaining circuit, means for obtaining etc. The obtaining unit 1405 may be a processor 1401 of the network node 101 or comprised in the processor 1401 of the network node 101 . The obtaining unit 1405 may be a receiver, a transceiver or receiving port of the second network node 101 .

The cell deactivation time parameter obtained from the first network node 101 may be obtained in an IE, comprised in an existing message or a new message and obtained from the first network node 101 via a peer to peer interface, or the deactivation time parameter may be obtained from the first network node 101 via a RAN to RAN or RAN internal interface and by using an OSS.

The second network node 101 may be arranged to, e.g. by means of the providing unit 1403, provide the cell deactivation time parameter to a UE 105.

The second network node 101 may be arranged to, e.g. by means of the obtaining unit 1405, obtain, from the first network node 101 , cell identity information of other cells 103 that may at least partly cover an area of the first cell 103 when the first cell 103 is deactivated.

The second network node 101 may be arranged to, e.g. by means of the providing unit 1403, provide the cell identity information to the UE 105.

The present disclosure associated with the network node 101 may be implemented through one or more processors, such as a processor 1401 in the network node 101 depicted in fig. 14a, together with computer program code for performing the functions and actions described herein. A processor, as used herein, may be understood to be a hardware component. The program code mentioned above may also be provided as a computer program product, for instance in the form of a data carrier carrying computer program code for performing the present disclosure when being loaded into the network node 101 . One such carrier may be in the form of a CD ROM disc. It is however feasible with other data carriers such as a memory stick. The computer program code may be provided as pure program code on a server and downloaded to the network node 101 .

The network node 101 may comprise a memory 1410 comprising one or more memory units. The memory 1410 is arranged to be used to store obtained information, store data, configurations, schedulings, and applications etc. to perform the methods herein when being executed in the network node 101 .

The network node 101 may receive information from, e.g., the UE 105, through a receiving port 1414. The receiving port 1414 may be, for example, connected to one or more antennas in network node 101. The network node 101 may receive information from another structure in the communications system 100 through the receiving port 1414. Since the receiving port 1414 may be in communication with the processor 1401 , the receiving port 1414 may then send the received information to the processor 1401 . The receiving port 1414 may also be configured to receive other information.

The processor 1401 in the network node 101 may be configured to transmit or send information to e.g., the UE 105, or another structure in the communications system 100, through a sending port 1405, which may be in communication with the processor 1401 , and the memory 1410.

The network node 101 may comprise the determining unit 1400, the providing unit 1403, the obtaining unit 1405, and other unit(s) 1408.

Those skilled in the art will also appreciate that the determining unit 1400, the providing unit 1403, the obtaining unit 1405, and other unit(s) 1408 etc. described above may refer to a combination of analog and digital circuits, and/or one or more processors configured with software and/or firmware, e.g., stored in memory, that, when executed by the one or more processors such as the processor 1401 , perform as described above. One or more of these processors, as well as the other digital hardware, may be comprised in a single ASIC, or several processors and various digital hardware may be distributed among several separate components, whether individually packaged or assembled into a SoC.

Also, the different units described above may be implemented as one or more applications running on one or more processors such as the processor 1401 .

Thus, the methods described herein for the network node 101 may be respectively implemented by means of a computer program 1420 product, comprising instructions, i.e., software code portions, which, when executed on at least one processor 1401 , cause the at least one processor 1401 to carry out the actions described herein, as performed by the network node 101 . The computer program 1420 product may be stored on a computer-readable storage medium 1423. The computer-readable storage medium 1423, having stored thereon the computer program 1420, may comprise instructions which, when executed on at least one processor 1401 , cause the at least one processor 1401 to carry out the actions described herein, as performed by the network node 101. The computer-readable storage medium 1423 may be a non- transitory computer-readable storage medium, such as a CD ROM disc, or a memory stick. The computer program 1420 product may be stored on a carrier containing the computer program 1420 just described, wherein the carrier is one of an electronic signal, optical signal, radio signal, or the second computer-readable storage medium 1423, as described above.

The network node 101 may comprise a communication interface configured to facilitate communications between the network node 101 and other nodes or devices, e.g., the UE 105, or another structure. The interface may, for example, comprise a transceiver configured to transmit and receive radio signals over an air interface in accordance with a suitable standard.

The network node 101 may comprise the following arrangement depicted in fig.14b. The network node 101 may comprise a processing circuitry 1425, e.g., one or more processors such as the processor 1401 , in the network node 101 and the memory 1410. The network node 101 may also comprise a radio circuitry 1428, which may comprise e.g., the receiving port 1414 and the sending port 1415. The processing circuitry 1425 may be configured to, or operable to, perform the method actions according to fig. 1 -12 in a similar manner as that described in relation to fig. 14a. The radio circuitry 1428 may be configured to set up and maintain at least a wireless connection with the network node 101 . Circuitry may be understood herein as a hardware component.

The network node 101 may be operative to operate in the communications system 100. The network node 101 may comprise the processing circuitry 2101 and the memory 1410. The memory 1410 comprises instructions executable by the processing circuitry 1425. The network node 101 is operative to perform the actions described herein in relation to the network node 101 , e.g., in figs. 1 -12.

Fig. 15 shows an example of a communication system 1500 in accordance with some embodiments.

In the example, the communication system 1500 includes a telecommunication network 1502 that includes an access network 1504, such as a radio access network (RAN), and a core network 1506, which includes one or more core network nodes 1508. The access network 1504 includes one or more access network nodes, such as network nodes 1510a and 1510b (one or more of which may be generally referred to as network nodes 1510), or any other similar 3^rd Generation Partnership Project (3GPP) access node or non-3GPP access point. The network nodes 1510 facilitate direct or indirect connection of user equipment (UE), such as by connecting UEs 1512a, 1512b, 1512c, and 1512d (one or more of which may be generally referred to as UEs 1512) to the core network 1506 over one or more wireless connections.

Example wireless communications over a wireless connection include transmitting and/or receiving wireless signals using electromagnetic waves, radio waves, infrared waves, and/or other types of signals suitable for conveying information without the use of wires, cables, or other material conductors. Moreover, in different embodiments, the communication system 1500 may include any number of wired or wireless networks, network nodes, UEs, and/or any other components or systems that may facilitate or participate in the communication of data and/or signals whether via wired or wireless connections. The communication system 1500 may include and/or interface with any type of communication, telecommunication, data, cellular, radio network, and/or other similar type of system. The UEs 1512 may be any of a wide variety of communication devices, including wireless devices arranged, configured, and/or operable to communicate wirelessly with the network nodes 1510 and other communication devices. Similarly, the network nodes 1510 are arranged, capable, configured, and/or operable to communicate directly or indirectly with the UEs 1512 and/or with other network nodes or equipment in the telecommunication network 1502 to enable and/or provide network access, such as wireless network access, and/or to perform other functions, such as administration in the telecommunication network 1502.

In the depicted example, the core network 1506 connects the network nodes 1510 to one or more hosts, such as host 1516. These connections may be direct or indirect via one or more intermediary networks or devices. In other examples, network nodes may be directly coupled to hosts. The core network 1506 includes one more core network nodes (e.g., core network node 1508) that are structured with hardware and software components. Features of these components may be substantially similar to those described with respect to the UEs, network nodes, and/or hosts, such that the descriptions thereof are generally applicable to the corresponding components of the core network node 1508. Example core network nodes include functions of one or more of a Mobile Switching Center (MSC), Mobility Management Entity (MME), Home Subscriber Server (HSS), Access and Mobility Management Function (AMF), Session Management Function (SMF), Authentication Server Function (AUSF), Subscription Identifier De-concealing function (SIDF), Unified Data Management (UDM), Security Edge Protection Proxy (SEPP), Network Exposure Function (NEF), and/or a User Plane Function (UPF).

The host 1516 may be under the ownership or control of a service provider other than an operator or provider of the access network 1504 and/or the telecommunication network 1502 and may be operated by the service provider or on behalf of the service provider. The host 1516 may host a variety of applications to provide one or more service. Examples of such applications include live and pre-recorded audio/video content, data collection services such as retrieving and compiling data on various ambient conditions detected by a plurality of UEs, analytics functionality, social media, functions for controlling or otherwise interacting with remote devices, functions for an alarm and surveillance center, or any other such function performed by a server.

As a whole, the communication system 1500 of Figure 15 enables connectivity between the UEs, network nodes, and hosts. In that sense, the communication system may be configured to operate according to predefined rules or procedures, such as specific standards that include, but are not limited to: Global System for Mobile Communications (GSM); Universal Mobile Telecommunications System (UMTS); Long Term Evolution (LTE), and/or other suitable 2G, 3G, 4G, 5G standards, or any applicable future generation standard (e.g., 6G); wireless local area network (WLAN) standards, such as the Institute of Electrical and Electronics Engineers (IEEE) 802.11 standards (WiFi); and/or any other appropriate wireless communication standard, such as the Worldwide Interoperability for Microwave Access (WiMax), Bluetooth, Z-Wave, Near Field Communication (NFC) ZigBee, LiFi, and/or any low-power wide-area network (LPWAN) standards such as LoRa and Sigfox.

In some examples, the telecommunication network 1502 is a cellular network that implements 3GPP standardized features. Accordingly, the telecommunications network 1502 may support network slicing to provide different logical networks to different devices that are connected to the telecommunication network 1502. For example, the telecommunications network 1502 may provide Ultra Reliable Low Latency Communication (URLLC) services to some UEs, while providing Enhanced Mobile Broadband (eMBB) services to other UEs, and/or Massive Machine Type Communication (mMTC)/Massive loT services to yet further UEs.

In some examples, the UEs 1512 are configured to transmit and/or receive information without direct human interaction. For instance, a UE may be designed to transmit information to the access network 1504 on a predetermined schedule, when triggered by an internal or external event, or in response to requests from the access network 1504. Additionally, a UE may be configured for operating in single- or multi-RAT or multistandard mode. For example, a UE may operate with any one or combination of Wi-Fi, NR (New Radio) and LTE, i.e. being configured for multi-radio dual connectivity (MR- DC), such as E-UTRAN (Evolved-UMTS Terrestrial Radio Access Network) New Radio - Dual Connectivity (EN-DC). In the example, the hub 1514 communicates with the access network 1504 to facilitate indirect communication between one or more UEs (e.g., UE 1512c and/or 1512d) and network nodes (e.g., network node 151 Ob). In some examples, the hub 1514 may be a controller, router, content source and analytics, or any of the other communication devices described herein regarding UEs. For example, the hub 1514 may be a broadband router enabling access to the core network 1506 for the UEs. As another example, the hub 1514 may be a controller that sends commands or instructions to one or more actuators in the UEs. Commands or instructions may be received from the UEs, network nodes 1510, or by executable code, script, process, or other instructions in the hub 1514. As another example, the hub 1514 may be a data collector that acts as temporary storage for UE data and, in some embodiments, may perform analysis or other processing of the data. As another example, the hub 1514 may be a content source. For example, for a UE that is a VR headset, display, loudspeaker or other media delivery device, the hub 1514 may retrieve VR assets, video, audio, or other media or data related to sensory information via a network node, which the hub 1514 then provides to the UE either directly, after performing local processing, and/or after adding additional local content. In still another example, the hub 1514 acts as a proxy server or orchestrator for the UEs, in particular in if one or more of the UEs are low energy loT devices.

The hub 1514 may have a constant/persistent or intermittent connection to the network node 151 Ob. The hub 1514 may also allow for a different communication scheme and/or schedule between the hub 1514 and UEs (e.g., UE 1512c and/or 1512d), and between the hub 1514 and the core network 1506. In other examples, the hub 1514 is connected to the core network 1506 and/or one or more UEs via a wired connection. Moreover, the hub 1514 may be configured to connect to an M2M service provider over the access network 1504 and/or to another UE over a direct connection. In some scenarios, UEs may establish a wireless connection with the network nodes 1510 while still connected via the hub 1514 via a wired or wireless connection. In some embodiments, the hub 1514 may be a dedicated hub - that is, a hub whose primary function is to route communications to/from the UEs from/to the network node 1510b. In other embodiments, the hub 1514 may be a non-dedicated hub - that is, a device which is capable of operating to route communications between the UEs and network node 151 Ob, but which is additionally capable of operating as a communication start and/or end point for certain data channels.

Fig. 16 is a block diagram of a host 1600, which may be an embodiment of the host 1516 of Figure 15, in accordance with various aspects described herein. As used herein, the host 1600 may be or comprise various combinations hardware and/or software, including a standalone server, a blade server, a cloud-implemented server, a distributed server, a virtual machine, container, or processing resources in a server farm. The host 1600 may provide one or more services to one or more UEs.

The host 1600 includes processing circuitry 1602 that is operatively coupled via a bus 1604 to an input/output interface 1606, a network interface 1608, a power source 1610, and a memory 1612. Other components may be included in other embodiments. Features of these components may be substantially similar to those described with respect to the devices of previous figures, such as Figures 13 and 14, such that the descriptions thereof are generally applicable to the corresponding components of host 1600.

The memory 1612 may include one or more computer programs including one or more host application programs 1614 and data 1616, which may include user data, e.g., data generated by a UE for the host 1600 or data generated by the host 1600 for a UE. Embodiments of the host 1600 may utilize only a subset or all of the components shown. The host application programs 1614 may be implemented in a container-based architecture and may provide support for video codecs (e.g., Versatile Video Coding (VVC), High Efficiency Video Coding (HEVC), Advanced Video Coding (AVC), MPEG, VP9) and audio codecs (e.g., FLAC, Advanced Audio Coding (AAC), MPEG, G.71 1 ), including transcoding for multiple different classes, types, or implementations of UEs (e.g., handsets, desktop computers, wearable display systems, heads-up display systems). The host application programs 1614 may also provide for user authentication and licensing checks and may periodically report health, routes, and content availability to a central node, such as a device in or on the edge of a core network. Accordingly, the host 1600 may select and/or indicate a different host for over-the-top services for a UE. The host application programs 1614 may support various protocols, such as the HTTP Live Streaming (HLS) protocol, Real-Time Messaging Protocol (RTMP), Real-Time Streaming Protocol (RTSP), Dynamic Adaptive Streaming over HTTP (MPEG-DASH), etc.

Fig. 17 shows a communication diagram of a host 1702 communicating via a network node 1704 with a UE 1706 over a partially wireless connection in accordance with some embodiments. Example implementations, in accordance with various embodiments, of the UE (such as a UE 105 of Figure 13a and/or UE 105 of Figure 13b), network node (such as network node 101 of fig. 14B and/or network node 101 of fig. 14B), and host (such as host 1516 of fig. 15 and/or host 1600 of fig. 16) discussed in the preceding paragraphs will now be described with reference to fig. 17.

Like host 1600, embodiments of host 1702 include hardware, such as a communication interface, processing circuitry, and memory. The host 1702 also includes software, which is stored in or accessible by the host 1702 and executable by the processing circuitry. The software includes a host application that may be operable to provide a service to a remote user, such as the UE 1706 connecting via an over-the-top (OTT) connection 1750 extending between the UE 1706 and host 1702. In providing the service to the remote user, a host application may provide user data which is transmitted using the OTT connection 1750.

The network node 1704 includes hardware enabling it to communicate with the host 1702 and UE 1706. The connection 1760 may be direct or pass through a core network (like core network 1506 of Figure 15) and/or one or more other intermediate networks, such as one or more public, private, or hosted networks. For example, an intermediate network may be a backbone network or the Internet.

The UE 1706 includes hardware and software, which is stored in or accessible by UE 1706 and executable by the UE’s processing circuitry. The software includes a client application, such as a web browser or operator-specific “app” that may be operable to provide a service to a human or non-human user via UE 1706 with the support of the host 1702. In the host 1702, an executing host application may communicate with the executing client application via the OTT connection 1750 terminating at the UE 1706 and host 1702. In providing the service to the user, the UE's client application may receive request data from the host's host application and provide user data in response to the request data. The OTT connection 1750 may transfer both the request data and the user data. The UE's client application may interact with the user to generate the user data that it provides to the host application through the OTT connection 1750.

The OTT connection 1750 may extend via a connection 1760 between the host 1702 and the network node 1704 and via a wireless connection 1770 between the network node 1704 and the UE 1706 to provide the connection between the host 1702 and the UE 1706. The connection 1760 and wireless connection 1770, over which the OTT connection 1750 may be provided, have been drawn abstractly to illustrate the communication between the host 1702 and the UE 1706 via the network node 1704, without explicit reference to any intermediary devices and the precise routing of messages via these devices.

As an example of transmitting data via the OTT connection 1750, in step 1708, the host 1702 provides user data, which may be performed by executing a host application. In some embodiments, the user data is associated with a particular human user interacting with the UE 1706. In other embodiments, the user data is associated with a UE 1706 that shares data with the host 1702 without explicit human interaction. In step 1710, the host 1702 initiates a transmission carrying the user data towards the UE 1706. The host 1702 may initiate the transmission responsive to a request transmitted by the UE 1706. The request may be caused by human interaction with the UE 1706 or by operation of the client application executing on the UE 1706. The transmission may pass via the network node 1704, in accordance with the teachings of the embodiments described throughout this disclosure. Accordingly, in step 1712, the network node 1704 transmits to the UE 1706 the user data that was carried in the transmission that the host 1702 initiated, in accordance with the teachings of the embodiments described throughout this disclosure. In step 1714, the UE 1706 receives the user data carried in the transmission, which may be performed by a client application executed on the UE 1706 associated with the host application executed by the host 1702.

In some examples, the UE 1706 executes a client application which provides user data to the host 1702. The user data may be provided in reaction or response to the data received from the host 1702. Accordingly, in step 1716, the UE 1706 may provide user data, which may be performed by executing the client application. In providing the user data, the client application may further consider user input received from the user via an input/output interface of the UE 1706. Regardless of the specific manner in which the user data was provided, the UE 1706 initiates, in step 1718, transmission of the user data towards the host 1702 via the network node 1704. In step 1720, in accordance with the teachings of the embodiments described throughout this disclosure, the network node 1704 receives user data from the UE 1706 and initiates transmission of the received user data towards the host 1702. In step 1722, the host 1702 receives the user data carried in the transmission initiated by the UE 1706.

One or more of the various embodiments improve the performance of OTT services provided to the UE 1706 using the OTT connection 1750, in which the wireless connection 1770 forms the last segment. More precisely, the teachings of these embodiments may improve the mobility, energy saving, etc.

In an example scenario, factory status information may be collected and analyzed by the host 1702. As another example, the host 1702 may process audio and video data which may have been retrieved from a UE for use in creating maps. As another example, the host 1702 may collect and analyze real-time data to assist in controlling vehicle congestion (e.g., controlling traffic lights). As another example, the host 1702 may store surveillance video uploaded by a UE. As another example, the host 1702 may store or control access to media content such as video, audio, VR or AR which it can broadcast, multicast or unicast to UEs. As other examples, the host 1702 may be used for energy pricing, remote control of non-time critical electrical load to balance power generation needs, location services, presentation services (such as compiling diagrams etc. from data collected from remote devices), or any other function of collecting, retrieving, storing, analyzing and/or transmitting data.

In some examples, a measurement procedure may be provided for the purpose of monitoring data rate, latency and other factors on which the one or more embodiments improve. There may further be an optional network functionality for reconfiguring the OTT connection 1750 between the host 1702 and UE 1706, in response to variations in the measurement results. The measurement procedure and/or the network functionality for reconfiguring the OTT connection may be implemented in software and hardware of the host 1702 and/or UE 1706. In some embodiments, sensors (not shown) may be deployed in or in association with other devices through which the OTT connection 1750 passes; the sensors may participate in the measurement procedure by supplying values of the monitored quantities exemplified above, or supplying values of other physical quantities from which software may compute or estimate the monitored quantities. The reconfiguring of the OTT connection 1750 may include message format, retransmission settings, preferred routing etc.; the reconfiguring need not directly alter the operation of the network node 1704. Such procedures and functionalities may be known and practiced in the art. In certain embodiments, measurements may involve proprietary UE signaling that facilitates measurements of throughput, propagation times, latency and the like, by the host 1702. The measurements may be implemented in that software causes messages to be transmitted, in particular empty or ‘dummy’ messages, using the OTT connection 1750 while monitoring propagation times, errors, etc.

Summarized, whether the cell 103 goes into an outage due to a planned activity, or whether it goes into outage due to other reasons, the value of the period of cell outage is exchanged between network nodes 101 so that some actions are taking after the occurrence of a cell outage. Once a neighboring network node 101 receives the period of a cell outage, that period is then forwarded to all UEs 105 being served by the cells 103 of that neighboring network node 101 .

The cell deactivation time parameter, e.g. value of the duration of the outage, denoted here as T_cell1_outage, on one cell, e.g. 5G celH , is communicated to one or more network nodes 101 serving cells 103 neighbouring celH . Such communication may be done by adding a new parameter that represent cell deactivation time parameter to existing or new signalling messages signalled over the interfaces enabling inter node communication. As an example, such interfaces may be the XnAP and the F1 AP protocol.

Once the cell deactivation time parameter, e.g. the value of the cell deactivation time parameter, is received by a network node 101 serving a cell 103 that is neighbor to celH 103, e.g. by 5G cell2 103, THEN that latest cell2 103 may communicate one or both of the following two information to some or all of UEs 105 served by 5G cell2 103:

- information 1 : the value of cell deactivation time parameter cell1 received via Cell deactivation time parameter. information 2: the value of cell identities, e.g. PCIs, of some or all cells 103 that might cover the area of cell 1 103 after the outage is executed on 5G cell 1 103, e.g. suppose that 4G celH 103, e.g. with cell identity=11 , e.g. PCI = 11 , covers the area of 5G celll 103 after 5G cell 1 outage.

Based on information 1 and information 2, when the UE 105 served by 5G cell2 103, whether that UE 105 is in idle or or inactive mode or in connected mode, e.g. running any type of call, moves away from 5G cell2 103 and detects a radio signal from a 4G cell 103, THEN,

If the cell identity, e.g. PCI, of the encountered cell 103 is equal to value in info 2, that is cell identity= 11 , e.g. PCI = 11 , in this example, THEN that means the UE 105 is moving towards the area of 5G celll 103, and in that case, it will execute a new UEjo raced u re as follows: o The UE 105 camps on 4G celll 103 without performing as in prior art any signaling procedure, e.g. an attach procedure on 4G celll 103 etc., rather it will wait till cell deactivation time parameter expiry and then reestablish the call to celll 103 after the outage is ceased.

Otherwise, if the cell identity, e.g. PCI, of the encountered 4G cell 103 is different from the value in info 2, that is cell identity= 11 , e.g. PCI = 11 , in this example, THEN that means the UE 105 is NOT moving towards the area of celll 103, and in that case, it will execute prior art procedure as follows: o The UE 105 camps on 4G celll 103 and triggers, without any delay, any prior art signaling procedure, e.g. an attach procedure on 4G celll 103 etc.

For UEs 105, e.g. UE1 105, served by 5G cell2 103 and that are in connected mode AND running an application, e.g. denoted application_only_5G, that works on 5G technology but not on 4G: When UE1 105 moves towards 4G celll 103 which is covering the area of 5G celll 103 after its outage then,

In prior art the call running application_only_5G is released and the UE 105 goes into idle mode or inactive mode in 4G celll 103.

The UE1 105 executes a new UE procedure used in the second embodiment, where it camps on 4G celll 103 for a period cell deactivation time parameter, without performing any signaling procedure on 4G celll 103. Rather it waits until cell deactivation time parameter expiry, and when it detects again 5G celU 103 the application_only_5G call is resumed and hence it is not released as in the case of prior art.

Rather than sending to the UE 105 the cell deactivation time parameter over the air interface, that value may be hardcoded at the UE side.

As used herein, the denotation of “5G”, “4G” are used as exemplary “radio access technologies” (RAT)s. In general, the assumption is that the 5G RAT can provide a better service than a 4G RAT for example. Other RATs can also comprise 2G,3G, and future RATs such as 6Gs. Note that the description given herein focuses on a 3GPP cellular communications system and, as such, 3GPP terminology or terminology similar to 3GPP terminology is oftentimes used. Note that, in the description herein, reference may be made to the term “cell;” however, particularly with respect to 5G NR (New Radio) concepts, beams may be used instead of cells and, as such, it is important to note that the concepts described herein are equally applicable to both cells and beams.

The methods described herein are agnostic to the type of RAT supported by a network node 101 or cell 103. For reasons of simplicity, non limiting examples are given where cells are identified as 5G or 4G. However, the methods could apply to any cells of any RAT and to cells 103 of the same RAT.

Generally, all terms used herein are to be interpreted according to their ordinary meaning in the relevant technical field, unless a different meaning is clearly given and/or is implied from the context in which it is used. All references to a/an/the element, apparatus, component, means, step, etc. are to be interpreted openly as referring to at least one instance of the element, apparatus, component, means, step, etc., unless explicitly stated otherwise. The steps of any methods disclosed herein do not have to be performed in the exact order disclosed, unless a step is explicitly described as following or preceding another step and/or where it is implicit that a step must follow or precede another step.

In general, the usage of “first”, “second”, “third”, “fourth”, and/or “fifth” herein may be understood to be an arbitrary way to denote different elements or entities, and may be understood to not confer a cumulative or chronological character to the nouns they modify, unless otherwise noted, based on context.

The present disclosure is not limited to the above. Various alternatives, modifications and equivalents may be used. Therefore, disclosure herein should not be taken as limiting the scope. A feature may be combined with one or more other features.

The term “at least one of A and B” should be understood to mean “only A, only B, or both A and B.”, where A and B are any parameter, number, indication used herein etc.

It should be emphasized that the term “comprises/comprising” when used in this specification is taken to specify the presence of stated features, integers, steps or components, but does not preclude the presence or addition of one or more other features, integers, steps, components or groups thereof. It should also be noted that the words “a” or “an” preceding an element do not exclude the presence of a plurality of such elements.

The term “configured to” used herein may also be referred to as “arranged to”, “adapted to”, “capable of’ or “operative to”.

The steps of the methods may be performed in another order than the order in which they appear herein.

Claims

1 . A method performed by a User Equipment, UE, (105) for handling cell deactivation in a communications system (100), the UE (105) is currently served by a second network node (101 ) in a second cell (103), the method comprising: obtaining (310, 901 , 1001) a cell deactivation time parameter indicating duration of deactivation of coverage of a first cell (103), wherein the first cell (103) is a neighbor cell to the second cell (103); obtaining (310, 901 , 1002) cell identity information of other cells (103) that may at least partly cover an area of the first cell (103) when the first cell (103) is deactivated; determining (320, 330, 902, 1003) that the UE (105) moves away from the second cell (103) and approaches a third cell (103); comparing (320, 330, 903, 1004) the cell identity of the third cell (103) with the corresponding cell identity in the obtained cell identity information; and acting (904, 907, 1005) according to a result of the comparison.

2. The method according to claim 1 , wherein the acting (904, 907, 1005) according to a result of the comparison comprises: based on a result of the comparison, determining (904, 907, 1005) to

- Camp on the third cell (103) with (905) or without (907) establishing a communication connection with a third network node (101 ), or to

- not monitor paging signals on the third cell (103) (909) until the cell deactivation time has expired.

3. The method according to any of claim 2, wherein when the result of the comparison indicates that the cell identity of the third cell (103) is not the same as in the obtained cell identity information, then the method comprises: determining (320, 330, 600, 610, 620, 800, 904, 1006) that the UE (105) is not moving towards the area covered by the first cell (103); determining (320, 330, 600, 610, 620, 800, 904, 1007) to camp on the third cell (103); and establishing (320, 330, 600, 610, 620, 800, 905, 1008) a communication connection.

4. The method according to any of claims 2-3, wherein when the result of the comparison indicates that the cell identity of the third cell (103) is the same as in the obtained cell identity information, then the method comprises: determining (320, 330, 600, 610, 620 800, 906, 1009) that the UE (105) is moving towards the area covered by the first cell (103); and determining (320, 330, 600, 610, 620, 800, 906, 1010) whether or not the UE (105) is both in connected mode and runs a predetermined application.

5. The method according to claim 4, wherein when the UE (105) is not both in connected mode and runs the predetermined application, then the method comprises: determining (320, 330, 600, 610, 620, 800, 907, 1011 ) to camp (907) on the third cell (103) during the cell deactivation time and without establishing the communication connection; determining (320, 330, 600, 610, 620, 800, 908, 1012) to wait to camp on the first cell (103) until the cell deactivation time has expired; detecting (320, 330, 600, 610, 620, 800, 909, 1013) a signal from the first cell (103) after the cell deactivation time has expired; and determining (320, 330, 600, 610, 620, 800, 909, 1014) to camp on the first cell (103) when the signal from the first cell (103) has been detected.

6. The method according to claim 3, wherein when the UE (105) is both in connected mode and runs the predetermined application, then the method comprises: determining (320, 330, 600, 610, 620, 800, 909, 1015) to wait to camp on the third cell (103) until the cell deactivation time has expired; detecting (320, 330, 600, 610, 620, 800, 910, 1016) a signal from the first cell (103) after the cell deactivation time has expired; and determining (320, 330, 600, 610, 620, 800, 911 , 1017) to resume running the predetermined application when the signal from the first cell (103) has been detected.

7. The method according to any of the preceding claims, wherein the cell deactivation time parameter associated with the first cell (103) is:

- received from a network node (101 ), or

- hardcoded in the UE (105).

8. The method according to any of the preceding claims, wherein the cell identity information is obtained (901 ) from a network node (101 ).

9. The method according to any of the preceding claims, wherein the cell identity is a Physical Cell Identity, PCI, or a New Radio, NR, Cell Global Identity, or a Public Land Mobile Network identifier, PLMN-ld or a 36bit NR cell identity, NCI.

10. A User Equipment, UE, (105) for handling cell deactivation in a communications system (100), the UE (105) is currently served by a second network node (101 ) in a second cell (103), wherein the UE is arranged to: obtain a cell deactivation time parameter indicating duration of deactivation of coverage of a first cell (103), wherein the first cell (103) is a neighbor cell to the second cell (103); obtain cell identity information of other cells (103) that may at least partly cover an area of the first cell (103) when the first cell (103) is deactivated; determine that the UE (105) moves away from the second cell (103) and approaches a third cell (103); compare the cell identity of the third cell (103) with the corresponding cell identity in the obtained cell identity information; and to act according to a result of the comparison.

11 . A method performed by a first network node (101 ) for handling cell deactivation in a communications system (100), wherein the first network node (101 ) serves a first cell (103), and wherein the method comprises: providing (210, 300, 901 , 1101 ), to a second network node (101 ), a cell deactivation time parameter indicating duration of deactivation of coverage of a first cell (103), wherein the first cell (103) is a neighbor cell to a second cell (103) served by the second network node (101); and providing (210, 310, 901 , 1103), to the second network node (101 ), cell identity information of other cells (103) that may at least partly cover an area of the first cell (103) when the first cell (103) is deactivated.

12. The method according to claim 11 , comprising: determining (200, 1 102) the cell identify information by:

- extracting the cell identity information from a radio coverage map that comprises radio coverage of all cells (103) of all technologies at each geographical location of the communications system (100); and/or obtaining the cell identify information from another network node (101 ) .

13. The method according to any of claims 1 1 -12, comprising: determining (200, 1100) the cell deactivation time parameter.

14. The method according to claim 13, wherein the cell deactivation time parameter is determined (200, 1100) by one or more of the following: in case of a planned cell deactivation, the cell deactivation time parameter is determined in advance of the cell deactivation; and/or in case of an unplanned cell deactivation, the cell deactivation time parameter is determined based on historic values obtained for a same event(s) causing the cell deactivation; and/or in case of the unplanned cell deactivation, the cell deactivation time parameter is determined based on information associated with an event(s) and data preceding the cell deactivation and inferring the deactivation time for the first cell (103).

15. A first network node (101 ) for handling cell deactivation in a communications system (100), wherein the first network node (101) serves a first cell (103), wherein the first network node (101 ) is arranged to . provide, to a second network node (101 ), a cell deactivation time parameter indicating duration of deactivation of coverage of a first cell (103), wherein the first cell (103) is a neighbor cell to a second cell (103) served by the second network node (101 ); and to provide, to the second network node (101 ), cell identity information of other cells (103) that may at least partly cover an area of the first cell (103) when the first cell (103) is deactivated

16. A method performed by a second network node (101 ) for handling cell deactivation in a communications system (100), wherein the second network node (101 ) serves a second cell (103), and wherein the method comprises: obtaining (300, 901 , 1201 ), from a first network node (101 ), a cell deactivation time parameter indicating duration of deactivation of coverage of a first cell (103), wherein the first cell (103) is a neighbor cell to the second cell (103); providing (300, 901 , 1202) the cell deactivation time parameter to a User Equipment, UE, (105); obtaining (310, 901 , 1203), from the first network node (101 ), cell identity information of other cells (103) that may at least partly cover an area of the first cell (103) when the first cell (103) is deactivated; and providing (310, 901 , 1204) the cell identity information to the UE (105).

17. The method according to claim 16, wherein the cell deactivation time parameter obtained from the first network node (101 ) is obtained in an information element, IE, comprised in an existing message or in a new message and obtained from the first network node (101) via a peer-to-peer interface; or wherein the deactivation time parameter is obtained from the first network node (101 ) via a Radio Access Network, RAN, to RAN or RAN internal interface and by using an Operations Support System, OSS.

18. A second network node (101 ) for handling cell deactivation, wherein the second network node (101 ) serves a second cell (103), wherein the second network node (101 ) is arranged to . obtain, from a first network node (101 ), a cell deactivation time parameter indicating duration of deactivation of coverage of a first cell (103), wherein the first cell (103) is a neighbor cell to the second cell (103); provide the cell deactivation time parameter to a User Equipment, UE, (105); obtain, from the first network node (101 ), cell identity information of other cells (103) that may at least partly cover an area of the first cell (103) when the first cell (103) is deactivated; and to provide the cell identity information to the UE (105).

19. A computer program product comprising program code for performing, when executed by the processing circuitry, the method of any of claims 1 -9 and/or 11 -14 and/or 16-17.

20. A non-transitory computer-readable storage medium comprising instructions, which when executed by the processing circuitry, cause the processing circuitry to perform the method of any of claims 1 -9 and/or 11-14 and/or 16-17.