WO2020035155A1

WO2020035155A1 - Apparatus, method and computer program

Info

Publication number: WO2020035155A1
Application number: PCT/EP2018/072368
Authority: WO
Inventors: Anna Sillanpaa
Original assignee: Nokia Technologies Oy
Current assignee: Nokia Technologies Oy
Priority date: 2018-08-17
Filing date: 2018-08-17
Publication date: 2020-02-20
Anticipated expiration: 2021-02-17

Abstract

An apparatus. The apparatus comprises means for receiving, at the apparatus, a request to initiate one or more sessions to support one or more applications at a user equipment; and in response to the request, causing an update of one or more data radio bearers, when it is determined by the apparatus that the update is necessary in order to accommodate the one or more sessions at the user equipment.

Description

Apparatus, method and computer program

Field

This disclosure relates to communications, and more particularly to resource allocation in a wireless communication system. More particularly the disclosure relates to data radio bearers.

Background

In telecom and mobile systems, data radio bearers are allocated between a UE and a radio network over the air interface. This enables data to be conveyed between the UE and the radio network. Typically each UE supports a specific number of data radio bearers (DRBs).

Statement of invention

According to a first aspect there is provided an apparatus comprising means for: receiving, at the apparatus, a request to initiate one or more sessions to support one or more applications at a user equipment; and in response to the request, causing an update of one or more data radio bearers, when it is determined by the apparatus that the update is necessary in order to accommodate the one or more sessions at the user equipment.

According to an example, the causing an update of one or more data radio bearers comprises one or more of: adding one or more data radio bearers; removing one or more existing data radio bearers; modifying one or more existing data radio bearers.

Therefore according to an example the apparatus comprises means for performing the adding and/or removing and/or modification of the data radio bearers.

According to an example, the apparatus comprises means for determining that the one or more sessions to be initiated require one or more new quality of service flows and/or addition of one or more packet data unit sessions, the causing an update of one or more data radio bearers for accommodating the one or more new quality of service flows and/or one or more packet data unit sessions. According to an example, the one or more new quality of service flows are identified by a quality of service identifier.

According to an example, the causing an update of one or more data radio bearers is in accordance with one or more pre-configured rules.

According to an example, the causing an update of one or more data radio bearers comprises removing one or more existing data radio bearers, the removing one or more existing data radio bearers being in accordance with a pre-configured rule, the pre-configured rule configured to cause the apparatus to remove existing data radio bearers in an order from a data radio bearer having a lowest quality requirement to a data radio bearer having a highest quality requirement.

According to an example, the quality requirement comprising one or more of: a guaranteed bit-rate requirement; a non-guaranteed bit-rate requirement; a 5G quality of service indicator (501); an Ultra-Reliable Low-Latency Communications (URLLC) requirement; a critical communication requirement.

According to an example, the apparatus configured to cause re-mapping of one or more quality of service flows from a removed data radio bearer to another of the existing data radio bearers, wherein the re-mapping comprises re-mapping the quality of service flows to a data radio bearer next in the order from lowest quality requirement to highest quality requirement.

According to an example, the apparatus is configured to exclude one or more data radio bearers from removal.

According to an example, a data radio bearer comprising a quality of service flow separation indication is excluded from removal. According to another example, mission critical services data radio bearers are excluded from removal. According to an example a voice data radio bearer is excluded from removal. For example this could be an IMS voice with 5QI=1 , and a related possible signalling DRB, e.g. with 5QI = 5.

According to an example, the removing one or more existing data radio bearers being based on inactivity information of the one or more existing data radio bearers. According to an example, the inactivity information comprises information of an inactivity timer or an inactivity counter of the one or more data radio bearers.

According to an example, the removing one or more existing data radio bearers causes removal of an existing session, the apparatus comprising means for indicating the removal of the one or more data radio bearers towards the user equipment, and/or the apparatus comprising means for indicating the removal of the session to the core network.

According to an example the removed session comprises a removed packet data unit session.

According to an example, the apparatus comprises means for subsequently re- allocating a removed data radio bearer.

According to an example, the causing an update of one or more data radio bearers comprises adding one or more data radio bearers.

According to an example, the adding one or more data radio bearers is in response to determining that existing data radio bearers are unsuitable for the requested one or more sessions.

According to some examples, existing data radio bearers may be considered unsuitable for quality of service flows associated with a requested session, if the quality of sen/ice flows are not for a same packet data unit session and/or they do not meet the quality of service flow requirements or exceed them, which may make existing data radio bearers suboptimal from an operator system usage point of view.

According to an example, the causing an update of one or more data radio bearers comprises modifying one or more existing data radio bearers.

According to an example, the modifying the one or more existing data radio bearers comprises re-mapping one or more quality of service flows between the one or more existing data radio bearers, according to one or more rules.

According to an example, the one or more rules comprises a rule that the one or more quality of service flows are to be re-mapped according to a pre-configured order. According to an example the pre-configured order comprises an order that a quality of service flow is to be re-mapped to a data radio bearer having a next higher quality requirement than the data radio bearer from which the re-mapped quality of service flow originated from.

According to an example, the quality requirement comprising one or more of: a guaranteed bit-rate requirement; a non-guaranteed bit-rate requirement; a 5G quality of service indicator (5QI); an Ultra-Reliable Low-Latency Communications (URLLC) requirement; a critical communication requirement.

According to an example, the apparatus comprising means for using information of a maximum number of data radio bearers that can be supported by the user equipment, to determine whether a maximum number of data radio bearers of the user equipment has been exceeded.

According to an example, the maximum number indicating an absolute maximum number of data radio bearers that the user equipment can support, or the maximum number indicating a maximum number that the user equipment can support in addition to data radio bearers already used at the user equipment.

According to an example, the information of a maximum number of data radio bearers that can be supported by the user equipment being received in response to a request to initiate one or more additional data radio bearers at the user equipment.

According to an example, the information of a maximum number of data radio bearers that can be supported by the user equipment being explicitly received at the apparatus.

According to an example, the information of a maximum number of data radio bearers that can be supported by the user equipment being determined by the apparatus based on information received at the apparatus, for example information of IMEI software version of the user equipment.

According to an example the information of a maximum number of data radio bearers that the user equipment can support being received at the apparatus from a core network, for example based on operator policies. According to an example, the apparatus comprising means for storing the information of a maximum number of data radio bearers that can be supported by the user equipment.

According to an example, the information stored at the apparatus of a maximum number of data radio bearers that can be supported by the user equipment comprises information of one or more previous error cases and/or information of a number of supported data radio bearers in the user equipment.

According to an example the apparatus comprises means for using information that the user equipment is not able to support one or more additional data radio bearers, to determine whether the maximum number of data radio bearers has been exceeded. According to an example, the information comprises information that an error occurred indicating that the user equipment has run out of data radio bearers that can be supported by the user equipment, the information being explicitly received at the apparatus. According to an example, the information that no more data radio bearers can be supported by the user equipment being explicitly received at the apparatus, for example from the user equipment or core network.

According to an example, the apparatus comprises means for using information of whether the user equipment is able to support one or more additional data radio bearers to determine whether the maximum number of data radio bearers has been exceeded.

According to an example, the information that the user equipment is able to support one or more additional data radio bearers being explicitly received at the apparatus, for example from the user equipment or core network. According to an example, the one or more sessions to be initiated comprising one or more of: a packet data unit session; a packet data network session.

According to an example, the one or more sessions being identifiable by a unique set of: IP address; data network name (DNN) or an access point name (APN); and/or a PDU type. According to an example, the request to initiate one or more sessions may comprise a request to initiate one or more quality of service flows.

According to an example, the one or more applications comprise one or more of: an operator hosted application such as cable television; a third party hosted application reachable via internet or otherwise such as video streaming; real time or tactile gaming service(s); IMS voice service over 5G and/or LTE; IMS emergency service over 5G and/or LTE; IMS video over 5G and/or LTE; loT service(s).

According to an example the causing an update of one or more data radio bearers comprises sending an instruction from the apparatus to the user equipment.

According to an example the apparatus comprises a base station, for example a gNB.

According to an example, the means comprises at least one memory and at least one processor.

According to a second aspect there is provided an apparatus comprising means for: receiving an instruction from a base station to update one or more data radio bearers at the apparatus; and updating the one or more data radio bearers in order to accommodate a requested session to be initiated at the apparatus to support one or more applications at the apparatus.

According to an example, the updating the one or more data radio bearers comprising one or more of: adding one or more data radio bearers; removing one or more existing data radio bearers; modifying one or more existing data radio bearers.

According to an example, the apparatus comprising means for updating the one or more data radio bearers in accordance with one or more pre-configured rules.

According to an example, the updating the one or more data radio bearers comprising removing one or more existing data radio bearers, the removing one or more existing data radio bearers being in accordance with a pre-configured rule, the pre-configured rule configured to cause the apparatus to remove existing data radio bearers in an order from a data radio bearer having a lowest quality requirement to a data radio bearer having a highest quality requirement.

According to an example, the apparatus comprising means for providing data radio bearer inactivity information to the base station.

According to an example, the updating one or more data radio bearers comprises modifying one or more existing data radio bearers, and wherein the modifying the one or more existing data radio bearers comprises re-mapping one or more quality of service flows between the one or more existing data radio bearers, according to one or more rules.

According to an example, the one or more rules comprises a rule that the one or more quality of service flows are to be re-mapped according to a pre-configured order, the pre-configured order comprising an order that a quality of service flow is to be re-mapped to a data radio bearer having a next higher quality requirement than the data radio bearer from which the re-mapped quality of service flow originated from.

According to an example, the apparatus comprises means for providing to the base station information of a maximum number of data radio bearers that can be supported by the apparatus.

According to an example, the apparatus comprising a user equipment.

According to a third aspect there is provided an apparatus comprising at least one processor; and at least one memory including computer program code; the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus at least to perform: receiving, at the apparatus, a request to initiate one or more sessions to support one or more applications at a user equipment; and in response to the request, causing an update of one or more data radio bearers, when it is determined by the apparatus that the update is necessary in order to accommodate the one or more sessions at the user equipment.

According to an example, the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus at least to perform determining that the one or more sessions to be initiated require one or more new quality of service flows and/or addition of one or more packet data unit sessions, the causing an update of one or more data radio bearers for accommodating the one or more new quality of service flows and/or one or more packet data unit sessions.

According to an example, at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus at least to perform identifying the one or more new quality of service flows by a quality of service identifier.

According to an example, the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus at least to perform the causing an update of one or more data radio bearers in accordance with one or more pre-configured rules.

According to an example, the quality requirement comprising one or more of: a guaranteed bit-rate requirement; a non-guaranteed bit-rate requirement; a 5G quality of service indicator (5QI); an Ultra-Reliable Low-Latency Communications (URLLC) requirement; a critical communication requirement. According to an example, the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus at least to perform re-mapping of one or more quality of service flows from a removed data radio bearer to another of the existing data radio bearers, wherein the re-mapping comprises re-mapping the quality of service flows to a data radio bearer next in the order from lowest quality requirement to highest quality requirement.

According to an example, the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus at least to perform excluding one or more data radio bearers from removal.

According to an example, the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus at least to perform removing one or more existing data radio bearers based on inactivity information of the one or more existing data radio bearers.

According to an example, the inactivity information comprises information of an inactivity timer or an inactivity counter of the one or more data radio bearers.

According to an example, the apparatus comprises means for subsequently re- allocating a removed data radio bearer. According to an example, the causing an update of one or more data radio bearers comprises adding one or more data radio bearers.

According to an example, the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus at least to perform adding one or more data radio bearers in response to determining that existing data radio bearers are unsuitable for the requested one or more sessions.

According to an example, the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus at least to perform modifying the one or more existing data radio bearers comprising re-mapping one or more quality of service flows between the one or more existing data radio bearers, according to one or more rules.

According to an example, the one or more rules comprises a rule that the one or more quality of service flows are to be re-mapped according to a pre-configured order.

According to an example the pre-configured order comprises an order that a quality of service flow is to be re-mapped to a data radio bearer having a next higher quality requirement than the data radio bearer from which the re-mapped quality of service flow originated from.

According to an example, the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus at least to perform using information of a maximum number of data radio bearers that can be supported by the user equipment, to determine whether a maximum number of data radio bearers of the user equipment has been exceeded. According to an example, the maximum number indicating an absolute maximum number of data radio bearers that the user equipment can support, or the maximum number indicating a maximum number that the user equipment can support in addition to data radio bearers already used at the user equipment. According to an example, the information of a maximum number of data radio bearers that can be supported by the user equipment being received in response to a request to initiate one or more additional data radio bearers at the user equipment.

According to an example the information of a maximum number of data radio bearers that the user equipment can support being received at the apparatus from a core network, for example based on operator policies.

According to an example, the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus at least to perform storing the information of a maximum number of data radio bearers that can be supported by the user equipment.

According to an example, the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus at least to perform using information that the user equipment is not able to support one or more additional data radio bearers, to determine whether the maximum number of data radio bearers has been exceeded. According to an example, the information comprises information that an error occurred indicating that the user equipment has run out of data radio bearers that can be supported by the user equipment, the information being explicitly received at the apparatus.

According to an example, the information that no more data radio bearers can be supported by the user equipment being explicitly received at the apparatus, for example from the user equipment or core network.

According to an example, the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus at least to perform using information of whether the user equipment is able to support one or more additional data radio bearers to determine whether the maximum number of data radio bearers has been exceeded.

According to an example, the information that the user equipment is able to support one or more additional data radio bearers being explicitly received at the apparatus, for example from the user equipment or core network.

According to an example, the one or more sessions to be initiated comprising one or more of: a packet data unit session; a packet data network session.

According to an example, the one or more sessions being identifiable by a unique set of: IP address; data network name (DNN) or an access point name (APN); and/or a PDU type.

According to an example, the request to initiate one or more sessions may comprise a request to initiate one or more quality of service flows.

According to an example, the one or more applications comprises one or more of: an operator hosted application such as cable television; a third party hosted application reachable via internet or otherwise such as video streaming; real time or tactile gaming service(s); IMS voice service over 5G and/or LTE; IMS emergency service over 5G and/or LTE; IMS video over 5G and/or LTE; loT service(s).

According to an example the causing an update of one or more data radio bearers comprises sending an instruction from the apparatus to the user equipment. According to an example the apparatus comprises a base station, for example a gNB.

According to a fourth aspect there is provided an apparatus comprising at least one processor; and at least one memory including computer program code; the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus at least to perform: receiving an instruction from a base station to update one or more data radio bearers at the apparatus; and updating the one or more data radio bearers in order to accommodate a requested session to be initiated at the apparatus to support one or more applications at the apparatus.

According to an example, the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus at least to perform the updating the one or more data radio bearers by one or more of: adding one or more data radio bearers; removing one or more existing data radio bearers; modifying one or more existing data radio bearers.

According to an example, the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus at least to perform updating the one or more data radio bearers in accordance with one or more pre-configured rules.

According to an example, the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus at least to perform removing one or more existing data radio bearers, the removing one or more existing data radio bearers being in accordance with a pre-configured rule, the pre- configured rule configured to cause the apparatus to remove existing data radio bearers in an order from a data radio bearer having a lowest quality requirement to a data radio bearer having a highest quality requirement.

According to an example, the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus at least to perform re-mapping of one or more quality of service flows from a removed data radio bearer to another of the existing data radio bearers, wherein the re-mapping comprises re-mapping the quality of service flows to a data radio bearer next in the order from lowest quality requirement to highest quality requirement.

According to an example, the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus at least to perform providing data radio bearer inactivity information to the base station.

According to an example, the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus at least to perform modifying one or more existing data radio bearers, and wherein the modifying the one or more existing data radio bearers comprises re-mapping one or more quality of service flows between the one or more existing data radio bearers, according to one or more rules.

According to an example, the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus at least to perform providing to the base station information of a maximum number of data radio bearers that can be supported by the apparatus.

According to an example, the apparatus comprises a user equipment.

According to a fifth aspect there is provided a method comprising: receiving, at an apparatus, a request to initiate one or more sessions to support one or more applications at a user equipment; and in response to the request, causing an update of one or more data radio bearers, when it is determined by the apparatus that the update is necessary in order to accommodate the one or more sessions at the user equipment.

According to an example, the causing an update of one or more data radio bearers comprises one or more of: adding one or more data radio bearers; removing one or more existing data radio bearers; modifying one or more existing data radio bearers. According to an example, the method comprises determining that the one or more sessions to be initiated require one or more new quality of service flows and/or addition of one or more packet data unit sessions, the causing an update of one or more data radio bearers for accommodating the one or more new quality of service flows and/or one or more packet data unit sessions.

According to an example, the method comprises identifying the one or more new quality of service flows by a quality of service identifier.

According to an example, the method comprises causing the update of one or more data radio bearers in accordance with one or more pre-configured rules.

According to an example, the causing an update of one or more data radio bearers comprises removing one or more existing data radio bearers, the removing one or more existing data radio bearers being in accordance with a pre-configured rule, the method comprising, in accordance with the pre-configured rule, removing existing data radio bearers in an order from a data radio bearer having a lowest quality requirement to a data radio bearer having a highest quality requirement .

According to an example, the quality requirement comprises one or more of: a guaranteed bit-rate requirement; a non-guaranteed bit-rate requirement; a 5G quality of service indicator (5QI); an Ultra-Reliable Low-Latency Communications (URLLC) requirement; a critical communication requirement.

According to an example, the method comprises re-mapping one or more quality of service flows from a removed data radio bearer to another of the existing data radio bearers, wherein the re-mapping comprises re-mapping the quality of service flows to a data radio bearer next in the order from lowest quality requirement to highest quality requirement.

According to an example, the method comprises excluding one or more data radio bearers from removal.

According to an example, the method comprises removing one or more existing data radio bearers based on inactivity information of the one or more existing data radio bearers.

According to an example, the removing one or more existing data radio bearers causes removal of an existing session, the method comprising indicating the removal of the one or more data radio bearers towards the user equipment, and/or the method comprising indicating the removal of the session to the core network.

According to an example, the method comprises subsequently re-allocating a removed data radio bearer.

According to an example, the method comprises modifying one or more existing data radio bearers.

According to an example, the method comprises using information of a maximum number of data radio bearers that can be supported by the user

equipment, to determine whether a maximum number of data radio bearers of the user equipment has been exceeded.

According to an example, the method comprises receiving the information of a maximum number of data radio bearers that can be supported by the user equipment in response to a request to initiate one or more additional data radio bearers at the user equipment.

According to an example, the method comprises explicitly receiving the information of a maximum number of data radio bearers that can be supported by the user equipment.

According to an example, the method comprises determining the information of a maximum number of data radio bearers that can be supported by the user equipment based on information received at the apparatus, for example information of IMEI software version of the user equipment.

According to an example, the method comprises receiving the information of a maximum number of data radio bearers that the user equipment can support from a core network, for example based on operator policies. According to an example, the method comprises storing the information of a maximum number of data radio bearers that can be supported by the user equipment.

According to an example, the method comprises using information that the user equipment is not able to support one or more additional data radio bearers, to determine whether the maximum number of data radio bearers has been exceeded. According to an example, the information comprises information that an error occurred indicating that the user equipment has run out of data radio bearers that can be supported by the user equipment, the information being explicitly received at the apparatus.

According to an example, the method comprises using information of whether the user equipment is able to support one or more additional data radio bearers to determine whether the maximum number of data radio bearers has been exceeded.

According to an example, the request to initiate one or more sessions may comprise a request to initiate one or more quality of service flows. According to an example, the one or more applications comprise one or more of: an operator hosted application such as cable television; a third party hosted application reachable via internet or otherwise such as video streaming; real time or tactile gaming service(s); IMS voice service over 5G and/or LTE; IMS emergency service over 5G and/or LTE; IMS video over 5G and/or LTE; loT service(s).

According to an example, the method comprises causing the update of one or more data radio bearers by sending an instruction from the apparatus to the user equipment.

According to a sixth aspect there is provided a method, comprising: receiving, at an apparatus, an instruction from a base station to update one or more data radio bearers; and updating the one or more data radio bearers in order to accommodate a requested session to be initiated at the apparatus to support one or more applications at the apparatus.

According to an example, the method comprises updating the one or more data radio bearers in accordance with one or more pre-configured rules.

According to an example, the updating the one or more data radio bearers comprises removing one or more existing data radio bearers, the removing one or more existing data radio bearers being in accordance with a pre-configured rule, the pre-configured rule configured to cause the apparatus to remove existing data radio bearers in an order from a data radio bearer having a lowest quality requirement to a data radio bearer having a highest quality requirement.

According to an example, the method comprises re-mapping of one or more quality of service flows from a removed data radio bearer to another of the existing data radio bearers, wherein the re-mapping comprises re-mapping the quality of service flows to a data radio bearer next in the order from lowest quality requirement to highest quality requirement. According to an example, the method comprises providing data radio bearer inactivity information to the base station.

According to an example, the method comprises providing to the base station information of a maximum number of data radio bearers that can be supported by the apparatus.

According to an example, the apparatus comprises a user equipment.

According to a seventh aspect there is provided a computer program comprising instructions for causing an apparatus to perform at least the following: receiving, at the apparatus, a request to initiate one or more sessions to support one or more applications at a user equipment; and in response to the request, causing an update of one or more data radio bearers, when it is determined by the apparatus that the update is necessary in order to accommodate the one or more sessions at the user equipment.

According to an eighth aspect there is provided a computer program

comprising instructions for causing an apparatus to perform at least the following: receiving, at the apparatus, an instruction from a base station to update one or more data radio bearers; and updating the one or more data radio bearers in order to accommodate a requested session to be initiated at the apparatus to support one or more applications at the apparatus. According to a ninth aspect there is provided a non-transitory computer readable medium comprising program instructions for causing an apparatus to perform at least the following: receiving, at the apparatus, a request to initiate one or more sessions to support one or more applications at a user equipment; and in response to the request, causing an update of one or more data radio bearers, when it is determined by the apparatus that the update is necessary in order to accommodate the one or more sessions at the user equipment.

According to a tenth aspect there is provided a non-transitory computer readable medium comprising program instructions stored thereon for performing at least the following: receiving, at an apparatus, a request to initiate one or more sessions to support one or more applications at a user equipment; and in response to the request, causing an update of one or more data radio bearers, when it is determined by the apparatus that the update is necessary in order to accommodate the one or more sessions at the user equipment.

According to an eleventh aspect there is provided a non-transitory computer readable medium comprising program instructions for causing an apparatus to perform at least the following: receiving an instruction from a base station to update one or more data radio bearers at the apparatus; and updating the one or more data radio bearers in order to accommodate a requested session to be initiated at the apparatus to support one or more applications at the apparatus.

According to a twelfth aspect there is provided a non-transitory computer readable medium comprising program instructions stored thereon for performing at least the following: receiving an instruction from a base station to update one or more data radio bearers at an apparatus; and updating the one or more data radio bearers in order to accommodate a requested session to be initiated at the

apparatus to support one or more applications at the apparatus.

According to a thirteenth aspect there is provided an apparatus comprising: receiving circuitry configured to perform receiving, at the apparatus, a request to initiate one or more sessions to support one or more applications at a user equipment; and updating circuitry configured to perform, in response to the request, causing an update of one or more data radio bearers, when it is determined by the apparatus that the update is necessary in order to accommodate the one or more sessions at the user equipment.

According to a fourteenth aspect there is provided an apparatus comprising: receiving circuitry configured to perform receiving an instruction from a base station to update one or more data radio bearers at the apparatus; and updating circuitry configured to perform updating the one or more data radio bearers in order to accommodate a requested session to be initiated at the apparatus to support one or more applications at the apparatus.

Brief description of Figures

The invention will now be described in further detail, by way of example only, with reference to the following examples and accompanying drawings, in which:

Figure 1 shows a schematic example of a wireless communication system where the invention may be implemented;

Figure 2 is a signalling diagram showing a method according to an example;

Figure 3 is a signalling diagram showing a method according to an example;

Figure 4 is a signalling diagram showing a method according to an example;

Figure 5 is a signalling diagram showing a method according to an example;

Figure 6 is a signalling diagram showing a method according to an example;

Figure 7 is a signalling diagram showing a method according to an example;

Figure 8 is a signalling diagram showing a method according to an example;

Figure 9A is a flow chart showing a method according to an example;

Figure 9B is a flow chart showing a method according to an example;

Figure 10 shows an example of a communication device;

Figure 1 1 shows an example of a control apparatus;

Figure 12 schematically shows an example of a base station; Figure 13 schematically shows some parts of a 5G network.

Detailed description

Before explaining in detail the examples, certain general principles of a wireless communication system and mobile communication devices are briefly explained with reference to Figure 1 to assist in understanding the technology underlying the described examples.

In a wireless communication system 100, such as that shown in Figure 1 , a wireless communication devices, for example, user equipment (UE) or MTC devices 102, 104, 105 are provided wireless access via at least one base station or similar wireless transmitting and/or receiving wireless infrastructure node or point. Such a node can be, for example, a base station or an eNodeB (eNB), or in a 5G system a Next Generation NodeB (gNB), or other wireless infrastructure node. These nodes will be generally referred to as base stations. Base stations are typically controlled by at least one appropriate controller apparatus, so as to enable operation thereof and management of mobile communication devices in communication with the base stations. The controller apparatus may be located in a radio access network (e.g. wireless communication system 100) or in a core network (CN) (not shown) and may be implemented as one central apparatus or its functionality may be distributed over several apparatus. The controller apparatus may be part of the base station and/or provided by a separate entity such as a Radio Network Controller. In Figure 1 control apparatus 108 and 109 are shown to control the respective macro level base stations 106 and 107. In some systems, the control apparatus may additionally or alternatively be provided in a radio network controller. Other examples of radio access system comprise those provided by base stations of systems that are based on technologies such as 5G or new radio, wireless local area network (WLAN) and/or WiMax (Worldwide Interoperability for Microwave Access). A base station can provide coverage for an entire cell or similar radio service area.

In Figure 1 base stations 106 and 107 are shown as connected to a wider communications network 113 via gateway 112. A further gateway function may be provided to connect to another network.

The smaller base stations 116, 118 and 120 may also be connected to the network 113, for example by a separate gateway function and/or via the controllers of the macro level stations. The base stations 116, 118 and 120 may be pico or femto level base stations or the like. In the example, stations 1 16 and 1 18 are connected via a gateway 1 1 1 whilst station 120 connects via the controller apparatus 108. In some embodiments, the smaller stations may not be provided.

As mentioned above, in wireless systems such as 5G, data radio bearers (DRBs) are allocated between the UE and the radio network over the air interface. In Figure 1 a DRB is schematically shown at 122, between UE 102 and base station (e.g. gNB) 106. One or more DRBs can be used to convey application data for various applications with different quality of service (QoS) needs. Applications may be, for example, a voice application, a video application, an emergency call application etc. Some services may have stringent latency requirements, such as real time video, while another service may have stringent packet loss requirements but not so stringent latency requirements, such as file downloading.

Each UE typically supports a specific number of packet data unit (PDU) sessions. The PDU sessions may be indicated as UE capability information, and provided to the 5G RAN. The UE also supports a specific number of DRBs. The DRBs cater for various applications and their related QoS needs. For the supported DRBs, there may be further limitations, e.g. as to how many guaranteed bit rate (GBR), non- GBR or ultra-reliable low latency (URLLC) DRBs the UE may support. There may also be limitations of how many DRBs are supported for standalone (SA) mode and how many for non-standalone (NSA) mode. There may also be limitations of how many DRBs can be used for each or for a group of specific architecture variants such as 3, 3A and /or 3X, and how many in UL and DL.

It may occur that a user is using services and applications typically requiring more DRBs than their UE supports. Thus, it has been identified by the present inventor that there is a need to be able to handle a situation where a UE does not support a requested or typical number of DRBs with applications being used or requested by the user. For 5G, 3GPP has mandated that a UE needs to support 16 DRBs, but they could support e.g. up to 29 or 36 DRBs. However, it may be the case that in reality UEs may support fewer DRBs e.g. 8 DRBs, due to vendor restrictions. At the same time, the core network (CN) typically decides the number of QoS flows and their 5Qls (5G quality of service indicator) with PCRF (policy and charging rules function), or other information, and the CN may not know the number of UE supported DRBs. The UE or CN may provide the number of UE supported DRBs to RAN, which will use its mapping rules to allocate DRBs for the QoS flows. The RAN can map several QoS flows to same DRB with specific 5QI, but typically RAN tries to map each QoS flow with different 5QI to a separate DRB. Typically an IMS emergency call may require two DRBs (one with 5QI1 , another with 5QI5). An IMS voice call may require two to three DRBs, and possibly some further operator specific DRBs for high priority services. It is therefore possible that the UE runs out of DRBs, dependent on the number of QoS flows and their allocated 5Qls. This disclosure describes at least in part a mechanism to recover from such a situation. In some examples the recovery may be based either on UE rejection (e.g. rejection of a request to add a new DRB) or, if supported, based on provided UE capability information indicating the number of supported DRBs. The recovery (or avoidance of a needed recovery) may be particularly useful if IMS (IP multimedia subsystem) emergency call is initiated, as the legacy recovery procedure can be heavy, requiring one or more RRC connection reconfigurations and RRC connection re-establishment. However, the recovery procedure may also be important with other services such as IMS voice call, URLLC or specific operator defined services.

Thus according to some examples a base station (BS, e.g. gNB) may cause an update of one or more data radio bearers, when it is determined by the base station that the update is necessary in order to accommodate a requested session at a user equipment. The update may be carried out at the UE, and may also be carried out to the radio network providing the service to the user equipment. To this end it will be understood that in examples the DRBs are established in the radio network, as well as in the UEs. The update may comprise one or more of: adding one or more DRBs; removing one or more existing DRBs; modifying one or more existing DRBs. Therefore in examples if a DRB is added, removed or modified, then this may have an effect in the UE and/or the radio network. In some examples the requested session comprises a packet data network (PDU) session. In another example the requested session may comprise a packet data network (PDN) session.

The requested session may support one or more applications at the UE. Examples of such applications include: an Internet service; an operator hosted application such as cable television; a third party hosted application reachable via internet or otherwise such as video streaming, real time or tactile gaming service; IMS voice service over 5G; IMS emergency service over 5G; IMS video over 5G; loT service(s). These applications may comprise of one or more application flows, for example IMS voice comprises of voice payload and SIP signalling. The application flows may be mapped to one or more QoS flows in 5G or evolved LTE (LTE connected to 5G core) systems requiring one or more DRBs. Typically application or QoS flows of different applications cannot be mapped to a same DRB as they are handled by different sessions (PDU sessions, PDN connections, etc) in 5G, evolved LTE and other communication systems. Such DRB(s) may be guaranteed bit-rate (GBR) service or a non-GBR service and the QoS flows they carry may on one hand tolerate but on another hand require or benefit from specific QoS aspects such as priority level, jitter, latency, packet delay budget etc and thus they may be allocated different 5Qls and other QoS functionality. In some examples the UE may comprise, or have been pre-allocated or pre-configured with a“default” DRB. The default DRB may be considered as a DRB to be used for QoS flows. In some examples the default DRB is considered the DRB to be used for QoS flows, unless a specific DRB is allocated to the QoS flow e.g. based on its 5QI etc.

In some examples the accommodating the requested session comprises mapping a flow or flows of the requested session in to the default DRB. In other words the base station may be configured to cause the requested session to be accommodated in a predetermined data radio bearer of the UE. In some examples the BS may re-map any flows that were already in the predetermined data radio bearer to one or more other data radio bearers of the UE.

In some examples the accommodating the requested session comprises mapping existing flows in the UE to the default DRB. By“existing” flows is meant flows already present or configured at the UE (and/or at the RAN), prior to receiving the request for the new session. In other words this may be considered rearranging or re- mapping existing flows at the UE.“Existing” DRBs may be considered to mean DRBs already present or configured at the UE (and/or at the RAN), prior to receiving the request for the new session.

According to some examples the newly requested session may need one or more new flows (e.g. QoS flows). Therefore, in some examples the causing an update of one or more data radio bearers is for accommodating one or more new QoS flows that it has been determined are required. The new QoS flows may be identified by one or more QoS identifiers. In some examples the requested session comprises an internet protocol (IP) session, comprising one or more associated IP flows.

Where the new requested session is accommodated by existing DRBs of the UE (rather than establishing one or more new DRBs at the UE), this may be done in response to determining by the BS that the flows for the new session comprise non- GBR or mostly non-GBR data.

As mentioned above, the updating of the DRBs may include removal of one or more existing DRBs. The removal of one or more DRBs may be in accordance with a preconfigured one or more rules. In an example the preconfigured rules are stored at the gNB. In one example the pre-configured rule may be a rule that causes the gNB to cause removal of existing data radio bearers in an order from a data radio bearer having a lowest quality requirement to a data radio bearer having a highest quality requirement. The quality requirement may comprise one or more of: a guaranteed bit-rate requirement; a non-guaranteed bit-rate requirement; a 5G quality of service indicator (5QI); an Ultra-Reliable Low-Latency Communications (URLLC)

requirement. For example consider that there are two DRBs, a first DRB and a second DRB. The first DRB has a higher quality requirement than the second DRB. Accordingly, the second DRB will be removed before the first DRB, in such an example.

According to some examples, removal of one or more DRBs may result in existing flows needing to be moved from one DRB to another DRB. The original DRB location of a flow prior to re-mapping of the flow may be considered an originating DRB, and the DRB to which the flow is moved may be considered a destination DRB. Therefore according to some examples the gNB is configured to re-map one or more quality of service flows from a removed (originating) DRB to another of the DRBs (destination DRB). According to some examples the re-mapping comprises re- mapping the quality of service flows from the removed DRB (originating DRB) to a DRB (destination DRB) next in an order from DRB having lowest quality requirement to DRB having highest quality requirement. For example consider three DRBs: a first DRB, a second DRB that has a quality requirement higher than the first DRB, and a third DRB that has a quality requirement higher than the second DRB. If the first DRB is removed, then QoS flows that were in the first DRB will be moved to the second DRB, and so on. According to some examples the removing one or more DRBs is based on inactivity information of the one or more DRBs. The inactivity information may comprise information from an inactivity counter or an inactivity timer. The inactivity counter or inactivity timer may be located at the UE, at the BS, or in the CN.

Therefore according to some examples, the BS is configured to determine whether an inactivity counting and/or timer has expired for any of the DRBs of the user equipment, in trying to accommodate the new session at the UE. In some examples the BS causes the UE to remove a DRB based on inactivity counting or expired inactivity timer. This frees up capacity at the UE to add one or more new DRBs to accommodate the newly requested session. According to some examples with more than one DRB having inactivity counting and/or expired inactivity timer, the first removed DRB is that which has been inactive for the longest. Thus in some examples the inactivity is counted and that information is used for the decision about removing or not removing the DRB(s). In some examples the inactivity information (e.g. timer or counting) can be the sole reason for the decision for removing or not removing DRB, or one input to the decision. However in some examples it is not necessary that some inactivity has taken place. According to some examples there may be provided a separate“re-mapping” inactivity timer, and all the DRBs for which this timer has expired are considered as eligible for removal if needed. In an example, this may be the only input to be used. In other examples this may be one of a number of inputs that is used.

According to some examples, where a gNB causes removal (or de-allocation) of one or more DRBs, then the gNB may subsequently re-allocate those one or more previously removed DRBs.

According to some examples the removal of one or more DRBs causes an end to a PDU session, for example if the removed DRB was the last remaining DRB. When it is determined that the DRB removal has caused an end to a PDU session, then the BS may in response indicate this to the UE and/or the CN.

In some examples the BS excludes certain DRBs at the UE from being removable. For example the BS may be configured to not cause removal of any or specific QoS flows and/or 5Qls, and their related DRBs.

According to some examples the BS may consider certain types of data as allocable or de-allocable. For example the BS may consider certain network data slices as being capable of being mapped or re-mapped amongst DRBs in order to accommodate the new request. Likewise the BS may consider certain network slices as being unmovable or“out of bounds” in terms of re-mapping. In other words the BS may perform mapping or re-mapping of existing flows at the UE in a manner dependent upon a data type of those flows. For example the BS may consider existing GBR flows as being unsuitable for re-mapping.

According to some examples the BS is configured to determine that the updating of UE’s DRBs is necessary, in response to using information indicating that a maximum number of data radio bearers of the user equipment has been exceeded. In some examples the information of a maximum number of DRBs that a UE can support is sent from the UE to the BS. For example a UE may support 16 DRBs. If all 16 DRBs are in use by the UE when the request for the new session is received then the UE may indicate this to the BS. The indication may be explicit or implicit. The BS may then map or re-map the existing flows, and the new flows, amongst the maximum number of DRBs of the UE.

According to some examples the BS may determine that DRB updating of the UE is necessary, based on information stored at the BS. For example the BS may be configured with DRB information of one or more UEs e.g. maximum number of DRBs. DRB information may be received at the BS in UE capability information messages from one or more UEs, and the BS may then store that information. In some examples the BS may learn DRB capability information of UEs over time. For example the BS may learn from previous error cases. For example an error case may be where a UE has indicated that its maximum number of DRBs is exceeded. In other examples other means can be used to establish UE capability information e.g. UE IMEI sv (software version), or some indication from core NW, etc.

In some examples, the UE may provide DRB information as part of UE capability information provided to gNB. For example the information could comprise one or more of: number of DRBs; number of (standardized) non-GBR; GBR; URLLC; non-standard non-GBR 5QI; and/or non-standard GBR 5QI DRBs; number of DRBs per 5QI; UL and/or DL information.

In some examples the UE capability formats comprise one or more of: a number indicating the maximum number of supported DRBs; a plurality of numbers indicating the number of supported 5Qls/GBR and non-GBR DRBs; one or more numbers provided in an agreed order; a bitmap indicating each DRB supported and total number.

The UE capability formats could indicate DRB support, by way of example, as follows: 5 (standardized) non-GBR 5Qis, 3 (standardized) GBR 5Qls and 1 URLLC 5QI; 5 (standardized) non-GBR 5QI = 8/9, 3 (standardized) GBR 5QI =1/2 and 1 URLLC 5QI = A. The set could be specific to the number of DRBs or part of another set defining also other UE supported features.

In some examples the causing an update of one or more DRBs comprises causing one or more DRBs to be added. For example one or more DRBs may need to be added when it is determined that one or more existing DRBs are unsuitable for the session(s) that have been requested.

According to some examples, the causing an update of one or more DRBs comprises modifying one or more existing data radio bearers. The modifying may, in some examples, comprise an action other than adding or removing DRBs. For example the modification may comprise re-mapping flows between the existing DRBs, without adding or removing existing DRBs.

Figures 2 and 3 describe some examples in more detail. The examples of Figures 2 and 3 relate to new PDU session set-up. For example one or more DRBs may be set up for default DRB, and additional DRBs for QoS flows e.g. with various 5 Qis. Therefore Figures 2 and 3 may relate to where a request is made to initiate a new PDU session.

Figure 2 relates to an example of a new PDU session creation request, where there is no available DRB at a UE. In this example the context is 5G. A UE is schematically shown at 202, a base station (e.g. gNB) is schematically shown at 206, and CN is schematically shown at 224.

At S1 , BS 206 receives a PDU session creation request from the CN 224. For example the request may be received from an access management function (AMF) in the CN 224, over NGAP (NG application protocol) with PDU session resource setup request. In some examples the procedure could also be an initial context set-up, if the UE does not previously have UE context in RAN, including a case of no active PDU sessions with DRBs.

At S2, BS 206 determines from the request whether the request is for a new PDU session. At S2 the BS 206 also determines whether a new DRB is required in order to accommodate the new PDU session. When it is determined by BS 206 that a new DRB is required to satisfy the request, the base station 206 sends a request to the UE 202 for establishment of a new DRB. This is shown at S3. This request may be an RRC connection reconfiguration request.

In this example, at S4 the UE 202 determines that it does not have capacity to add another DRB. For example the maximum number of DRBs that the UE can support may already be used up.

At S5, the UE 202 informs the BS 206 that the UE cannot add the requested DRB. The message at S5 may also include a cause. For example, the cause may indicate“no more DRBs available”. Further information may also be comprised in the message at S5, for example a classifier such as“with requested 5QI”,“for non GBR”, “for GBR”,“for 5Qis x-y/x,y,z etc. In some examples the rejection at S5 is carried out by initiating RRC connection re-establishment with a re-establishment cause code “reconfiguration error, no more DRBs available”(or similar). For example the message at S5 may indicate“failure and new connection establishment”. The message at S5 may comprise an RRC re-establishment request. Therefore in some examples it may be considered that the UE needs to initiate RRC connection re-establishment procedure if RRC connection re-configuration fails e.g. if UE cannot support requested DRB(s).

In response to receiving the rejection, at S6 the BS 206 determines that the BS 206 needs to cause an update of one or more DRBs at the UE 202 in order to accommodate the new PDU session. At S6 the BS 206 also determines how to accommodate the DRBs (i.e. existing DRBs and newly requested DRB(s) at the UE 202. This may include allocation and/or reallocation of DRBs and/or new and existing flows within the DRBs. This, and the algorithms for doing so, are explained in more detail further below. In some examples, the determination at S6 determines that two or more DRBs need to be adjusted (or“pre-empted”). This may be the case if more than one 5QI is required, for example if an emergency call is established and both 5QI1 and 5QI5 DRBs need to be freed. S6 may comprise, for example, determining that an old or existing DRB needs to be removed, to be replaced with or re-allocated as a new DRB for the new PDU session

At S7, the BS 206 provides DRB allocation and/or re-allocation instructions to UE 202. The instructions comprise instructions of how the UE 202 should update its DRBs in order to accommodate the requested new PDU session. The DRB allocation instructions may include instructions for e.g. adding and/or removing DRBs. For example the adding/removing may be carried out with RRC connection re- establishment procedure or with new RRC connection reconfiguration request with adding or removing. That is in some examples the message at S7 comprises a RRC re-establishment message.

At S8, the UE implements the DRB(s) in accordance with the configured allocation and/or re-allocation.

Once the UE 202 has implemented the DRB(s), at S9 the UE 202 informs the BS 206 that the DRB set-up is complete. The message at S9 may comprise an RRC re-establishment complete message.

Then, at S10 the BS 206 completes DRB set-up procedure.

At S11 , the BS 206 acknowledges the completed DRB set-up to CN 224 . The message at S10 may be carried out over NGAP with PDU session resource setup response indicating the positive outcome.

In some examples the procedure may include the removal of a PDU session.

For example, if a last DRB of a PDU session is removed, this may be indicated to the CN at the end of the flow (e.g. at S11).

Figure 3 relates to an example where there is a new PDU session creation request, and the BS and/or CN are aware of the UE’s capability regarding maximum number of DRBs.

At S1 , BS 306 receives a PDU session creation request from the CN 324. For example the request may be received from an access management function (AMF) in the CN 324, over NGAP (NG application protocol) with PDU session resource setup request. In some examples the procedure could also be an initial context set-up, if the UE does not previously have UE context in RAN, including a case of no active PDU sessions with DRBs.

At S2, base station 306 determines from the request that it is for a new PDU session for the UE 302, and whether a new DRB is needed.

At S3 the base station 306 determines, based on an already (or“currently”) allocated number of DRBs at the UE 302 and the known maximum number of DRBs that the UE 302 can handle, whether the UE has capability to handle the further requested DRB. That is in this example the BS 306 is aware of DRB capability information of the UE 306. In other words the BS 306 is configured to determine whether DRB updating is necessary at UE 302, based on information stored at the apparatus 306. The information stored at the BS 306 may comprise one or more of: information of a number (i.e. quantity) of currently allocated DRBs for the UE; information of a maximum number (i.e. quantity) of the UE’s DRB capability; information that the UE does not have any free or available DRBs. In some examples the BS 306 may determine the maximum number of supported DRBs for the UE based on one or more of: UE capability information received from the UE 302; earlier rejection from the UE 302; an RRC feature group; an earlier explicit UE indication of DRB allocation/deallocation (e.g. 1 DRB left); UE IMEI/IMEI software version (and related configuration, etc.). At least for a case of requested 5QI, there could be UE specific limitations not only for a number of DRBs but for specific 5QI, GBR/non-GBR, URLLC etc.

At S4, the BS 306 determines how to update the existing DRBs at the UE 302 in order to accommodate the new DRB (if necessary).

At S5, the BS 306 instructs the UE 302 how to update its DRBs. The message at S4 may for example comprise a RRC connection reconfiguration request message. The message at S4 may for example comprise an instruction for the UE 302 to add or remove one or more DRBs.

At S6, the UE implements the instructed change to its DRBs.

At S7, the UE sends a response to the BS 306 indicating to the BS that the DRB updating has been completed. In some examples this comprises an RRC connection reconfiguration complete message.

At S8 the BS 306 completes DRB set-up procedure.

At S9, the BS 306 acknowledges the completed DRB set-up to CN 324. The message at S9 may be carried out over NGAP with PDU session resource setup response indicating the positive outcome.

In some examples, the new flow to be added (i.e. flow associated with the requested session at S1 of Figures 2 and 3) may be a quality of service (QoS) flow. In such examples the procedure is the same or similar to the procedure described with respect to Figures 2 and 3). Some differences may include that the NGAP procedure is typically PDU session resource modify request/response. Furthermore, the QoS flow may be mapped to a PDU session’s default DRB or another existing DRB. If this is not possible the DRB may be released.

This is explained in more detail with respect to Figures 4 and 5 which relate to QoS flow updates within PDU session(s). In such cases, the new DRB may not be absolutely required but may be beneficial e.g. if new GBR DRB is needed for IMS voice or IMS emergency call voice payload with 5QI1. Therefore in these examples the updating of DRBs may comprise modification to existing DRBs e.g. to re-map flows (e.g. QoS flows) between the DRBs.

Reference is now made to Figure 4. Figure 4 is similar to the flow chart of Figure

2, so for conciseness the differences are explained below.

The request at S1 may be for (a) a new PDU session with QoS flows and 5 Qls in addition to the default DRB, or (b) QoS flows in addition to an existing PDU session. The DRBs for the QoS flows may be established immediately or later at any time.

Between S1 and S2 there is shown ST, where the BS acknowledges the request of S1. Alternatively ST may occur at the end of the flow. The procedure may include the removal of a PDU session e.g. if the last DRB of a PDU session is removed, then this may be indicated to the core network with S1’ at the end of the flow.

S2 may follow immediately after S1 (e.g. in direct response to the request of S1), or may occur sometime later. In this example, at S2 it is determined that new

DRB(s) are needed for QoS flows.

Reference is now made to Figure 5. Figure 5 is similar to the flow chart of Figure

3, so for conciseness the differences are explained below.

The acknowledgement at ST may take place between S1 and S2 (as shown), or may take place at the end of the flow. The procedure may include removal of the PDU session e.g. if the last DRB of the PDU session is removed, then this may be indicated to the CN 524 with S1’ at the end of the flow.

At S2 the BS 506 determines if new DRB(s) are needed for QoS flow(s).

Figures 6 and 7 provide some 5G specific examples. The flow chart of Figure 6 is similar to the flow chart of Figure 2, and the flow chart of Figure 7 is similar to the flow chart of Figure 3, although as mentioned from a 5G implementation perspective.

Referring to Figure 6, it can be seen that initially the UE is in an RRC connected state.

The session request message at S1 comprises a PDU session resource setup request.

At S2 it is determined if the request is for a new PDU session. At S3, the request sent to the UE 602 for a new or additional DRB is comprised in an RRC connection reconfiguration message.

At S4, the UE 202 determines that it cannot add the new DRB. In this example this is considered an error situation or error condition, requiring RRC connection reestablishment with an implementable DRB setting.

Accordingly, at S5 the UE 602 sends an RRC connection re-establishment request message to gNB 606.

At S6, the gNB 606 determines how to accommodate the DRBs.

Following the determination at S6, the gNB sends a DRB allocation to UE 602 at S7. In this example this is carried out by way of an RRC connection re-establishment message.

At S8 the UE 202 implements the DRBs according to the instruction.

At S9 the UE 602 indicates that the RRC connection re-establishment is complete.

At S10 the gNB 606 completes the DRB set-up.

At S11 the gNB 606 indicates the completed set-up to the CN 624. In this example this is by means of a PDU session resource setup response message.

Referring to Figure 7, it can be seen that the UE is initially in an RRC connected state.

At S1 , the CN 724 sends a PDU session resource setup request message to gNB 706.

At S2 the gNB 706 determines that the request is for a new PDU.

At S3, the gNB 706 determines if the UE can handle or support a new DRB.

At S4, the gNB 706 determines how to update DRBs at the UE.

At S5, the gNB 706 sends an instruction to UE 702 for implementing DRBs. In this example this is by means of an RRC connection reconfiguration message.

At S6, the UE 702 implements the instructed DRB configuration.

At S7 the UE 702 informs the gNB 706 that the DRB updating has been implemented by the DRB, in this example by means of an RRC connection reconfiguration complete message.

At S8 the gNB 706 completes the DRB set-up.

At S9 the gNB 706 indicates the completed DRB set-up by means of a PDU session resource setup response message to CN 724 at S9. There will now be described in more detail some algorithms or rules which may be implemented when freeing or releasing or removing one or more DRBs at a UE. For example, when a UE comprises a plurality of DRBs (e.g. 8, 16, 29, 36), these rules may be used when determining which of those DRBs to free or release, when it is determined that a DRB needs to be freed or released in order to accommodate a new session request. These rules may be stored at the BS or at the UE. Likewise these rules may be implemented at the UE or at the BS. In one example these rules are stored and implemented at the BS.

According to some examples the rules specify an order in which DRBs are to be removed or released.

According to an example rule, a DRB to be released comprises a lowest non- GBR (GBR/URLLC/non-standard non-GBR/GBR) 5QI DRB of each PDU session, when there is another non-GBR (GBR...) DRB to which a QoS flow(s) can be mapped. Therefore a rule may specify that a non-GBR DRB should be freed.

According to an example rule, a DRB to be released may comprise a lowest non- default (i.e. non pre-determined) non-GBR (GBR/URLLC/non-standard non- GBR/GBR) 5QI DRB of each PDU session. Therefore a rule may specify that DRBs other than certain, default DRBs can be released.

According to an example rule, DRBs may be released in a preconfigured order. For example there could be one configuration for all 5Qls, or separate ones, e.g. for some or all of the following: non-GBR 5Qls, GBR 5Qls, non-standard 5Qls (GBR and non-GBR separately), URLLC 5Qls. Therefore DRBs may be released in a preconfigured order, according to DRB type. According to some examples, specific values may be excluded from eligible 5Qls, e.g. default DRB of the PDU session, URLLC 5QI(s), specific non-standard 5QI(s). In addition, 5QI1 (IMS voice payload DRB), 5QI5 (IMS voice SIP signaling DRB). According to an example, the preconfigured order in which DRBs are dropped could be starting from the lowest 5QI (excluding or including default DRB), e.g. first 5QI9 DRB if exists, after that 5QI8 DRB if exists, and so on.

According to an example rule, a DRB may be released based on inactivity (e.g. an inactivity timer). To this end the BS and/or UE may be configured with the timer. In one example, a DRB having the longest inactivity is released. Additionally or alternatively, one or more DRBs may be released after a specific (preconfigured) inactivity time. According to an example rule, DRBs with specific network slices may be considered as not to be released, or to be releasable. That is a rule may specify whether or not a DRB can be released, based on a type of data flow in that DRB. For example a DRB with a“QoS flow separation” indication may be excluded from eligible DRB candidates to be removed. Likewise a mission critical DRB may be excluded from removal. According to an example, one or more UE’s DRBs could be left in reserve, and thus not all allocated before starting to allocate different QoS flows to a same DRB. According to an example a pre-configured order for releasing DRBs may be based on types of data flows in the DRBs. That is some types of data flows may be considered more important than others and therefore given a higher priority. For example a first DRB may have a first data flow having a first priority. A second DRB may have a second data flow having a second priority. The first priority is higher than the second priority. Accordingly a rule may mandate that the second DRB is removed before the first DRB.

It is to be noted that ARP (allocation and retention priority) priority level, preemption vulnerability and capability may also be taken into account, as standardized by 3GPP, as well as with the above aspects. In some examples standardized ARP rules may be used first, and when ARP values are equal, use the above described rules or algorithms.

According to some examples, RAN may also use the UE provided number of supported PDU sessions in making a decision of which DRBs to release. For example if the UE has already reached a maximum number of supported PDU sessions then RAN should reject the request towards the core network if the newly received request is for a new PDU session.

There will now be described in more detail some algorithms or rules which may be implemented when mapping or re-mapping QoS flow(s) or 5QI(s) to and/or between one or more DRBs. For example, in order to accommodate a new session request in to a UE’s DRBs, it may be necessary to re-map or redistribute existing flows amongst the DRBs. Again, the rules may define a pre-configured order of DRBs between which the flows should be moved. For example the pre-configured order may comprise an order that a QoS flow is to be re-mapped to a DRB having a next higher quality requirement than a DRB from which the re-mapped QoS flow originated from. For example say there are three DRBs: a first DRB having a first quality requirement, and a second DRB having a second quality requirement that is higher than the first quality requirement, and a third DRB having a third quality requirement that is lower than the first quality requirement. When being re-mapped, a QoS flow originating from the first DRB may be re-mapped to the second DRB rather than the third DRB, according to an example.

In an example, RAN may use a configurable (or a preconfigured) numeric limit for a“typical” PDU session and/or DRB amount. For example, as long as the number is not exceeded, new DRBs are allocated for the UE. For example if a UE has capacity for 8 DRBs but is only utilising 7 when a new session request is received, then the remaining available DRB may simply be allocated for the new session request. Conversely, if the maximum value is exceeded, then existing flows (e.g. QoS flows) may be re-mapped amongst existing DRBs in order to accommodate the new request. As previously discussed there may be exceptions to this. For example flows of the following type may be excluded from re-mapping (or at least be given a higher priority so as to reduce a likelihood of re-mapping): IMS voice; IMS emergency call; URLLC; NW slice; and/or other configured 5QI e.g. for operator specific applications such as MEC, DRB interactive gaming.

RAN may also use the UE provided or an otherwise known number of supported DRB in deciding mapping/re-mapping of flows. For example there may be configurable (or preconfigured) offset values indicating that if a UE has e.g. 2 DRBs left then no more DRBs are allocated or only allocated for some specific cases, e.g. specific 5Qls, NW slices, ARP values etc. Accordingly in some examples the BS and/or UE may be configured to always configure one or more unused or reserved DRBs at the UE. The reserved DRB(s) can be used to accommodate flows of new session requests, and/or accommodate existing flows in certain situations.

In an example rule, flows may be mapped or re-mapped based on lowest or highest non-GBR (GBR/URLLC/non-standard non-GBR/GBR) 5QI DRB of each PDU session. Likewise a rule may mandate that flows are mapped or re-mapped in a preconfigured and/or configurable order. For example there could be an order for all 5Qls, or selected 5Qls, and/or grouped 5Qls e.g. for any combination of: non-GBR 5Qls, GBR 5Qls, non-standard 5Qls (GBR and non-GBR separately), URLLC 5Qls, and based on the configuration each 5QI QoS flow may be allocated to corresponding 5QI DRB. For example 5QI=7 and 5QI=8 may be be mapped to 5QI=9. That is in some examples a mapping order granularity may be configurable. That is in some examples not all QoS flows are treated equally, and some QoS flows may be given higher or lower priority than other QoS flows. In some examples a specific value may be allocated to specific 5QI DRBs, e.g. default DRBs of the PDU session, specific URLLC, specific non-std 5QI, etc. In addition, DRBs such as 5QI1 (IMS voice payload DRB), 5QI5 (IMS voice SIP signaling DRB) may be given priority. In some examples the pre-configured order could be starting from the lowest (or highest) 5QI (excluding or including default DRB), e.g. first 5QI9 DRB if exists, after that 5QI8 DRB if exists, and so on. In some examples DRBs with specific network slices can be considered (configured/pre-configured) according to specific rules, e.g. DRB always allocated per 5QI, only one DRB always allocated, or specific rules per specific 5QI(s), or specific order for the 5Qls. According to an example a DRB with“QoS flow separation” indication can be excluded from eligible DRB candidates.

It is to be noted that ARP priority level, pre-emption vulnerability and capability can be taken into account with the above aspects, e.g. considered first, and when ARP values are equal, use the above rules.

Figure 8 shows a signaling flow from 3GPP TS37.340. The flow is between a UE, a master node (MN), a secondary node (SN), a serving gateway (S-GW) and a mobility management entity (MME). This flow shows a basic successful 3x signaling flow on E-RAB/DRB addition for an additional 3x split bearer. This flow is a generic option for EN-DC and 3/3X/3a flow, and not necessarily specific to 3X.

According to some examples of this disclosure, if the MN knows, based on UE capability or previous error condition from UE, that the UE does not have any more free DRBs, then the MN adds new E-RAB/DRB(s) and removes the same number of existing E-RAB/RB(s) from the UE. This process may be incorporated in the flow of Figure 4 (e.g. using the RRC messages).

If the UE does not have any more free DRBs and the MN is unaware, the flow may start as shown in Figure 4. The RRC connection reconfiguration may be rejected by the UE, by invoking RRC connection re-establishment initiated with cause code “reconfiguration error” towards MN. An additional code may be added indicating that the UE has no more DRBs to be allocated (for EN-DC).

The MN may then either:

• Cancel adding the E-RAB/DRB: Remove the added 3X E-RAB/DRB by initiating new SgNB modification request procedure towards SN. The Random access procedure towards SN as well as all the steps 7-1 1 may be omitted; or • MN could add new E-RAB/DRB(s) and remove same number of E- RAB/DRB(s), e.g if ARP indicates so This could be done with the same flow of Figure 4, starting afresh after the RRC connection re-establishment.

Figure 9A is a flow chart schematically showing a method according to an example, viewed from the perspective of an apparatus such as a base station.

At S1 , the method comprises receiving, at an apparatus, a request to initiate one or more sessions to support one or more applications at a user equipment.

At S2, the method comprises causing an update of one or more data radio bearers, when it is determined by the apparatus that the update is necessary in order to accommodate the one or more sessions at the user equipment.

Figure 9B is a flow chart schematically showing a method according to an example, viewed from the perspective of an apparatus such as a user equipment.

At S1 , the method comprises receiving, at an apparatus, an instruction from a base station to update one or more data radio bearers.

At S2, the method comprises updating the one or more data radio bearers in order to accommodate a requested session to be initiated at the apparatus to support one or more applications at the apparatus.

A possible wireless communication device which may be used in conjunction with the described examples will now be described in more detail with reference to Figure 10 showing a schematic, partially sectioned view of a communication device 1600. Such a communication device is often referred to as user equipment (UE) or terminal. An appropriate mobile communication device may be provided by any device capable of sending and receiving radio signals. Non-limiting examples comprise a mobile station (MS) or mobile device such as a mobile phone or what is known as a ’smart phone’, a computer provided with a wireless interface card or other wireless interface facility (e.g., USB dongle), personal data assistant (PDA) or a tablet provided with wireless communication capabilities, or any combinations of these or the like. A mobile communication device may provide, for example, communication of data for carrying communications such as voice, electronic mail (email), text message, multimedia and so on. Users may thus be offered and provided numerous services via their communication devices. Non-limiting examples of these services comprise two- way or multi-way calls, data communication or multimedia services or simply an access to a data communications network system, such as the Internet. Users may also be provided broadcast or multicast data. Non-limiting examples of the content comprise downloads, television and radio programs, videos, advertisements, various alerts and other information.

A wireless communication device may be for example a mobile device, that is, a device not fixed to a particular location, or it may be a stationary device. The wireless device may need human interaction for communication, or may not need human interaction for communication. In the present teachings the terms UE or“user” are used to refer to any type of wireless communication device.

The wireless device 1600 may receive signals over an air or radio interface 1607 via appropriate apparatus for receiving and may transmit signals via appropriate apparatus for transmitting radio signals. In Figure 10 transceiver apparatus is designated schematically by block 1606. The transceiver apparatus 1606 may be provided for example by means of a radio part and associated antenna arrangement. The antenna arrangement may be arranged internally or externally to the wireless device.

A wireless device is typically provided with at least one data processing entity 1601 , at least one memory 1602 and other possible components 1603 for use in software and hardware aided execution of tasks it is designed to perform, including control of access to and communications with access systems and other communication devices. The data processing, storage and other relevant control apparatus can be provided on an appropriate circuit board and/or in chipsets. This feature is denoted by reference 1604. The user may control the operation of the wireless device by means of a suitable user interface such as key pad 1605, voice commands, touch sensitive screen or pad, combinations thereof or the like. A display 1608, a speaker and a microphone can be also provided. Furthermore, a wireless communication device may comprise appropriate connectors (either wired or wireless) to other devices and/or for connecting external accessories, for example hands-free equipment, thereto. The communication devices 1602, 1604, 1605 may access the communication system based on various access techniques.

Figure 1 1 shows an example of a control apparatus for a communication system, for example to be coupled to and/or for controlling a station of an access system, such as a RAN node, e.g. a base station, gNB, a central unit of a cloud architecture or a node of a core network such as an MME or S-GW, a scheduling entity such as a spectrum management entity, or a server or host. The control apparatus may be integrated with or external to a node or module of a core network or RAN. In some embodiments, base stations comprise a separate control apparatus unit or module. In other embodiments, the control apparatus can be another network element such as a radio network controller or a spectrum controller. In some embodiments, each base station may have such a control apparatus as well as a control apparatus being provided in a radio network controller. The control apparatus 1700 can be arranged to provide control on communications in the service area of the system. The control apparatus 1700 comprises at least one memory 1701 , at least one data processing unit 1702, 1703 and an input/output interface 1704. Via the interface 1704 the control apparatus can be coupled to a receiver and a transmitter of the base station. The receiver and/or the transmitter may be implemented as a radio front end or a remote radio head. For example the control apparatus 1700 or processor 1701 can be configured to execute an appropriate software code to provide the control functions.

Although in some examples the base station (e.g. 206, 306, 406, 506, 606, 706) is shown as a single entity, it will be understood that the base station may comprise a central unit (CU) and a distributed unit (DU). There may be an interface between the CU(s) and DU(s). The message flows described herein may include messaging between the CU(s) and DU(s). Figure 12 schematically shows such a gNB 1006. In this example the gNB 1006 comprises a gNB-CU 1050. In this example the gNB 1006 comprises gNB-DUs 1052 and 1054, which communicate with gNB-CU 1050 over the F1 interface. Generally speaking a gNB 1006 may comprise one or more gNB-CUs and one or more gNB-DUs.

Figure 13 schematically shows some aspects of a 5G network 1300 for context. The 5G network 1300 shows a UE 1302 in communication with RAN 1304. The RAN 1304 is in communication with user plane function (UPF) 1306, which is in turn in communication with data network (DN) 1308. The UPF 1306 is further in communication with session management function (SMF) 1310. Also shown are access and mobility management function (AMF) 1312, policy control function (PCF) 1314, and application function (AF) 1316. AMF 1312 is also communicatively connected to Network Slice Selection Function (NSSF) 1318 and Authentication Server Function (AUSF) 1320. A Unified Data Management entity (UDM) is further shown at 1322. It will be understood that some examples may operate in such a 5G network. Although some of the described examples relate to 5G, it will be understood that examples may also relate to“evolved LTE” (LTE connected to 5G core), or indeed other access technologies.

In general, the various embodiments may be implemented in hardware or special purpose circuits, software, logic or any combination thereof. Some aspects of the invention may be implemented in hardware, while other aspects may be implemented in firmware or software which may be executed by a controller, microprocessor or other computing device, although the invention is not limited thereto. While various aspects of the invention may be illustrated and described as block diagrams, flow charts, or using some other pictorial representation, it is well understood that these blocks, apparatus, systems, techniques or methods described herein may be implemented in, as non-limiting examples, hardware, software, firmware, special purpose circuits or logic, general purpose hardware or controller or other computing devices, or some combination thereof.

As used in this application, the term“circuitry” may refer to one or more or all of the following: (a) hardware-only circuit implementations (such as implementations in only analog and/or digital circuitry) and(b) combinations of hardware circuits and software, such as (as applicable): (i) a combination of analog and/or digital hardware circuit(s) with software/fimnware and (ii) any portions of hardware processor(s) with software (including digital signal processor(s)), software, and memory(ies) that work together to cause an apparatus, such as a mobile phone or server, to perform various functions) and (c) hardware circuit(s) and or processor(s), such as a microprocessor(s) or a portion of a microprocessor(s), that requires software (e.g., firmware) for operation, but the software may not be present when it is not needed for operation. This definition of circuitry applies to all uses of this term in this application, including in any claims. As a further example, as used in this application, the term circuitry also covers an implementation of merely a hardware circuit or processor (or multiple processors) or portion of a hardware circuit or processor and its (or their) accompanying software and/or firmware. The term circuitry also covers, for example and if applicable to the particular claim element, a baseband integrated circuit or processor integrated circuit for a mobile device or a similar integrated circuit in server, a cellular network device, or other computing or network device.

The embodiments of this invention may be implemented by computer software executable by a data processor of the mobile device, such as in the processor entity, or by hardware, or by a combination of software and hardware. Computer software or program, also called program product, including software routines, applets and/or macros, may be stored in any apparatus-readable data storage medium and they comprise program instructions to perform particular tasks. A computer program product may comprise one or more computer-executable components which, when the program is run, are configured to carry out embodiments. The one or more computer-executable components may be at least one software code or portions of it.

Further in this regard it should be noted that any blocks of the logic flow as in the Figures may represent program steps, or interconnected logic circuits, blocks and functions, or a combination of program steps and logic circuits, blocks and functions. The software may be stored on such physical media as memory chips, or memory blocks implemented within the processor, magnetic media such as hard disk or floppy disks, and optical media such as for example DVD and the data variants thereof, CD. The physical media is a non-transitory media.

The memory may be of any type suitable to the local technical environment and may be implemented using any suitable data storage technology, such as semiconductor based memory devices, magnetic memory devices and systems, optical memory devices and systems, fixed memory and removable memory. The data processors may be of any type suitable to the local technical environment, and may comprise one or more of general purpose computers, special purpose computers, microprocessors, digital signal processors (DSPs), application specific integrated circuits (ASIC), FPGA, gate level circuits and processors based on multi core processor architecture, as non-limiting examples.

Embodiments of the inventions may be practiced in various components such as integrated circuit modules. The design of integrated circuits is by and large a highly automated process. Complex and powerful software tools are available for converting a logic level design into a semiconductor circuit design ready to be etched and formed on a semiconductor substrate.

The foregoing description has provided by way of non-limiting examples a full and informative description of the exemplary embodiment of this invention. However, various modifications and adaptations may become apparent to those skilled in the relevant arts in view of the foregoing description, when read in conjunction with the accompanying drawings and the appended claims. However, all such and similar modifications of the teachings of this invention will still fall within the scope of this invention as defined in the appended claims. Indeed there is a further embodiment comprising a combination of one or more embodiments with any of the other embodiments previously discussed.

Claims

1. An apparatus comprising means for: receiving, at the apparatus, a request to initiate one or more sessions to support one or more applications at a user equipment; and in response to the request, causing an update of one or more data radio bearers, when it is determined by the apparatus that the update is necessary in order to accommodate the one or more sessions at the user equipment.

2. An apparatus according to claim 1 , wherein the causing an update of one or more data radio bearers comprises one or more of: adding one or more data radio bearers; removing one or more existing data radio bearers; modifying one or more existing data radio bearers.

3. An apparatus according to claim 1 or claim 2, wherein the apparatus comprises means for determining that the one or more sessions to be initiated require one or more new quality of service flows and/or addition of one or more packet data unit sessions, the causing an update of one or more data radio bearers for accommodating the one or more new quality of service flows and/or one or more packet data unit sessions.

4. An apparatus according to any preceding claim, wherein the causing an update of one or more data radio bearers is in accordance with one or more p re- configured rules.

5. An apparatus according to claim 2, wherein the causing an update of one or more data radio bearers comprises removing one or more existing data radio bearers, the removing one or more existing data radio bearers being in accordance with a pre-configured rule, the pre-configured rule configured to cause the apparatus to remove existing data radio bearers in an order from a data radio bearer having a lowest quality requirement to a data radio bearer having a highest quality

requirement.

6. An apparatus according to claim 5, the quality requirement comprising one or more of: a guaranteed bit-rate requirement; a non-guaranteed bit-rate requirement; a 5G quality of service indicator (5QI); an Ultra-Reliable Low-Latency Communications (URLLC) requirement; a critical communication requirement.

7. An apparatus according to claim 5 or claim 6, the apparatus configured to cause re-mapping of one or more quality of service flows from a removed data radio bearer to another of the existing data radio bearers, wherein the re-mapping comprises re-mapping the quality of service flows to a data radio bearer next in the order from lowest quality requirement to highest quality requirement.

8. An apparatus according to any of claims 5 to 7, wherein the apparatus is configured to exclude one or more data radio bearers from removal.

9. An apparatus according to any of claims 5 to 8, the removing one or more existing data radio bearers being based on inactivity information of the one or more existing data radio bearers.

10. An apparatus according to any of claims 5 to 9, wherein the removing one or more existing data radio bearers causes removal of an existing session, the

apparatus comprising means for indicating the removal of the one or more data radio bearers towards the user equipment, and/or the apparatus comprising means for indicating the removal of the session to the core network.

11. An apparatus according to claim 2, wherein the causing an update of one or more data radio bearers comprises adding one or more data radio bearers.

12. An apparatus according to claim 11 , wherein the adding one or more data radio bearers is in response to determining that existing data radio bearers are unsuitable for the requested one or more sessions.

13. An apparatus according to claim 2, wherein the causing an update of one or more data radio bearers comprises modifying one or more existing data radio bearers.

14. An apparatus according to claim 13, wherein the modifying the one or more existing data radio bearers comprises re-mapping one or more quality of service flows between the one or more existing data radio bearers, according to one or more rules.

15. An apparatus according to claim 14, wherein the one or more rules comprises a rule that the one or more quality of service flows are to be re-mapped according to a pre-configured order.

16. An apparatus according to any preceding claim, the apparatus comprising means for using information of a maximum number of data radio bearers that can be supported by the user equipment, to determine whether a maximum number of data radio bearers of the user equipment has been exceeded.

17. An apparatus according to claim 16, the maximum number indicating an absolute maximum number of data radio bearers that the user equipment can support, or the maximum number indicating a maximum number that the user equipment can support in addition to data radio bearers already used at the user equipment.

18. An apparatus according to claim 16 or claim 17, the information of a maximum number of data radio bearers that can be supported by the user equipment being received in response to a request to initiate one or more additional data radio bearers at the user equipment.

19. An apparatus according to any of claims 16 to 18, comprising means for storing the information of a maximum number of data radio bearers that can be supported by the user equipment.

20. An apparatus according to any preceding claim, the one or more sessions to be initiated comprising one or more of: a packet data unit session; a packet data network session.

21. An apparatus according to any preceding claim, wherein the one or more applications comprises one or more of: an operator hosted application such as cable television; a third party hosted application reachable via internet or otherwise such as video streaming; real time or tactile gaming service(s); IMS voice service over 5G and/or LTE; IMS emergency service over 5G and/or LTE; IMS video over 5G and/or LTE; loT service(s).

22. An apparatus comprising means for: receiving an instruction from a base station to update one or more data radio bearers at the apparatus; and updating the one or more data radio bearers in order to accommodate a requested session to be initiated at the apparatus to support one or more

applications at the apparatus.

23. An apparatus according to claim 22, the updating the one or more data radio bearers comprising one or more of: adding one or more data radio bearers; removing one or more existing data radio bearers; modifying one or more existing data radio bearers.

24. An apparatus according to claim 22 or claim 23, comprising means for updating the one or more data radio bearers in accordance with one or more p re- configured rules.

25. An apparatus according to claim 23, the updating the one or more data radio bearers comprising removing one or more existing data radio bearers, the removing one or more existing data radio bearers being in accordance with a pre-configured rule, the pre-configured rule configured to cause the apparatus to remove existing data radio bearers in an order from a data radio bearer having a lowest quality requirement to a data radio bearer having a highest quality requirement.

26. An apparatus according to claim 25, the apparatus configured to cause remapping of one or more quality of service flows from a removed data radio bearer to another of the existing data radio bearers, wherein the re-mapping comprises remapping the quality of service flows to a data radio bearer next in the order from lowest quality requirement to highest quality requirement.

27. An apparatus according to any of claims 22 to 26, the apparatus comprising means for providing data radio bearer inactivity information to the base station.

28. An apparatus according to claim 23, wherein the updating one or more data radio bearers comprises modifying one or more existing data radio bearers, and wherein the modifying the one or more existing data radio bearers comprises re- mapping one or more quality of service flows between the one or more existing data radio bearers, according to one or more rules.

29. An apparatus according to claim 28, wherein the one or more rules comprises a rule that the one or more quality of service flows are to be re-mapped according to a pre-configured order, the pre-configured order comprising an order that a quality of service flow is to be re-mapped to a data radio bearer having a next higher quality requirement than the data radio bearer from which the re-mapped quality of service flow originated from.

30. An apparatus according to any of claims 22 to 29, comprising means for providing to the base station information of a maximum number of data radio bearers that can be supported by the apparatus.

31. An apparatus according to any of claims 22 to 30, the apparatus comprising a user equipment.

32. A method comprising: receiving, at an apparatus, a request to initiate one or more sessions to support one or more applications at a user equipment; and in response to the request, causing an update of one or more data radio bearers, when it is determined by the apparatus that the update is necessary in order to accommodate the one or more sessions at the user equipment.

33. A method, comprising: receiving, at an apparatus, an instruction from a base station to update one or more data radio bearers; and updating the one or more data radio bearers in order to accommodate a requested session to be initiated at the apparatus to support one or more

applications at the apparatus.

34. A computer program comprising instructions for causing an apparatus to perform at least the following: receiving, at the apparatus, a request to initiate one or more sessions to support one or more applications at a user equipment; and in response to the request, causing an update of one or more data radio bearers, when it is determined by the apparatus that the update is necessary in order to accommodate the one or more sessions at the user equipment.

35. A computer program comprising instructions for causing an apparatus to perform at least the following: receiving, at the apparatus, an instruction from a base station to update one or more data radio bearers; and updating the one or more data radio bearers in order to accommodate a requested session to be initiated at the apparatus to support one or more

applications at the apparatus.