WO2024260546A1

WO2024260546A1 - Method and arrangements regarding positioning of a relay node to relay communication for wireless device(s) in a wireless communication network

Info

Publication number: WO2024260546A1
Application number: PCT/EP2023/066737
Authority: WO
Inventors: Niklas JALDÉN; Anders FURUSKÄR; Thomas Lejon
Original assignee: Telefonaktiebolaget LM Ericsson AB
Current assignee: Telefonaktiebolaget LM Ericsson AB
Priority date: 2023-06-21
Filing date: 2023-06-21
Publication date: 2024-12-26
Anticipated expiration: 2025-12-21

Abstract

Method and arrangements regarding positioning of a first relay node (115) for relaying communication between a first radio network node (110) of a wireless communication network (100) and one or more first wireless devices (120a-b) located in a certain area (125; 152a; 152b). It is initiated to move (503; 801) a measurement node (115; 215) along a path (216; 316; 416) comprising one or more candidate positions (218;318; 418) for positioning of the relay node (115). It is initiated to evaluate (508; 802) at least one of said one or more candidate positions (218; 318; 418) to find a candidate position (218-5; 318-10; 418-6) for positioning of the first relay node (115) to perform said relaying. The evaluation of a respective candidate position is based on measurements performed by the first measurement node (115; 215) on both relay-link (122) and a access-link (124) when positioned in the respective candidate position.

Description

METHOD AND ARRANGEMENTS REGARDING POSITIONING OF A RELAY NODE TO RELAY COMMUNICATION FOR WIRELESS DEVICE(S) IN A WIRELESS COMMUNICATION NETWORK

TECHNICAL FIELD

Embodiments herein concern methods and arrangements that relate to wireless communication networks and evaluation of candidate positions for positioning of a relay node to relay communication for one or more wireless devices located in a certain area of the wireless communication network. The relayed communication is via the relay node between a first radio network node of a wireless communication network and said one or more first wireless devices.

BACKGROUND

Communication devices such as wireless communication devices, that simply may be named wireless devices, may also be known as e.g. user equipments (UEs), mobile terminals, wireless terminals and/or mobile stations. A wireless device is enabled to communicate wirelessly in a wireless communication network, wireless communication system, or radio communication system, e.g. a telecommunication network, sometimes also referred to as a cellular radio system, cellular network or cellular communication system. The communication may be performed e.g. between two wireless devices, between a wireless device and a regular telephone and/or between a wireless device and a server via a Radio Access Network (RAN) and possibly one or more core networks, comprised within the cellular communication network. The wireless device may further be referred to as a mobile telephone, cellular telephone, laptop, Personal Digital Assistant (PDA), tablet computer, just to mention some further examples. Wireless devices may be so called Machine to Machine (M2M) devices or Machine Type of Communication (MTC) devices, i.e. devices that are not associated with a conventional user.

The wireless device may be, for example, portable, pocket-storable, hand-held, computer-comprised, or vehicle-mounted mobile device, enabled to communicate voice and/or data, via the RAN, with another entity, such as another wireless device or a server.

The wireless communication network may cover a geographical area which is divided into cell areas, wherein each cell area is served by at least one base station, or Base Station (BS), e.g. a Radio Base Station (RBS), which sometimes may be referred to as e.g. “eNB”, “eNodeB”, “NodeB”, “B node”, “gNB”, or BTS (Base Transceiver Station), depending on the technology and terminology used. The base stations may be of different classes such as e.g. macro eNodeB, home eNodeB or pico base station, based on transmission power and thereby also cell size. A cell is typically identified by one or more cell identities. The base station at a base station site may provide radio coverage for one or more cells. A cell is thus typically associated with a geographical area where radio coverage for that cell is provided by the base station at the base station site. Cells may overlap so that several cells cover the same geographical area. By the base station providing or serving a cell is typically meant that the base station provides radio coverage such that one or more wireless devices located in the geographical area where the radio coverage is provided may be served by the base station in said cell. When a wireless device is said to be served in or by a cell this implies that the wireless device is served by the base station providing radio coverage for the cell. Further, each base station may support one or several communication technologies. The base stations communicate over the air interface operating on radio frequencies with the wireless device within range of the base stations.

The expression downlink (DL) may be used for the transmission path from the base station to the wireless device. The expression uplink (UL) may be used for the transmission path in the opposite direction i.e. from the wireless device to the base station.

In some RANs, several base stations may be connected, e.g. by landlines or microwave, to a radio network controller, e.g. a Radio Network Controller (RNC) in Universal Mobile Telecommunication System (UMTS), and/or to each other. The radio network controller, also sometimes termed a Base Station Controller (BSC) e.g. in GSM, may supervise and coordinate various activities of the plural base stations connected thereto. GSM is an abbreviation for Global System for Mobile Communication (originally: Groupe Special Mobile), which may be referred to as 2nd generation or 2G.

UMTS is a third generation mobile communication system, which may be referred to as 3rd generation or 3G, and which evolved from the GSM, and provides improved mobile communication services based on Wideband Code Division Multiple Access (WCDMA) access technology. UMTS Terrestrial Radio Access Network (UTRAN) is essentially a radio access network using wideband code division multiple access for wireless devices. High Speed Packet Access (HSPA) is an amalgamation of two mobile telephony protocols, High Speed Downlink Packet Access (HSDPA) and High Speed Uplink Packet Access (HSUPA), defined by 3rd Generation Partnership Project (3GPP), that extends and improves the performance of existing 3rd generation mobile telecommunication networks utilizing the WCDMA. Such networks may be named WCDMA/HSPA.

The 3GPP has undertaken to evolve further the LITRAN and GSM based radio access network technologies, for example into evolved LITRAN (E-UTRAN) used in Long Term Evolution (LTE). In LTE, base stations, referred to as eNodeBs or eNBs, may be directly connected to other base stations and may be directly connected to one or more core networks. LTE is often referred to as 4th generation or 4G.

3GPP has specified and development work has continued with a fifth generation (5G) of wide area wireless communication networks, and even development with a further generation (6G) has begun.

There is an ongoing increasing demand for higher connection speed, improved quality of service and increasing number of connected wireless devices. This requires a continuous growth in network capacity. This has been addressed, and is continued to be addressed, by each new generation of wireless communication network and technology and by improvements to existing technologies. However, several studies indicate that at some point in time it will no longer be sufficient to meet traffic demands by just additional frequencies, improved antennas and/or more computational power on existing sites. Another solution is to densify the network by adding more sites.

One large component in the cost for deploying a new site is ‘backhaul’, i.e. some communication means connecting the base station on the site to the rest of the network. This can be handled e.g. via fiber connections, or wireless links using either micro-wave technology. One initiative to reduce the transmission cost is to use cellular technology also for the link connecting the base station with the network. This is commonly referred to as relaying.

Another large cost component is the cost for acquiring and renting the site location itself, e.g. a place on a roof for an antenna and a penthouse for a base station. To reduce this cost, and to be flexible in the placement of the new node, it has been proposed to let drones, small aircrafts, carry base stations, and fly in positions where it is desired to place a site. In “Deployment of UAV-Mounted Access Points According to Spatial User Locations in Two-Tier Cellular Networks", B. Galkin, J. Kibilda and LA. DaSilva, published at 2016 Wireless Days (WD) they show the gains of using drone based small cells compared to classically deployed small sites. SUMMARY

In view of the above, an object is to enable or provide one or more improvements or alternatives in relation to the prior art, such as to support or facilitate higher capacity and/or quality of service, for example higher connection speed and increasing number of connected wireless devices, in a wireless communication network.

According to a first aspect of embodiments herein, the object is achieved by a method, performed by one or more devices, regarding positioning of a first relay node for relaying communication between a first radio network node of a wireless communication network and one or more first wireless devices located in a certain area. It is initiated to move a measurement node along a path comprising one or more candidate positions for positioning of the first relay node. It is initiated to evaluate at least one of said one or more candidate positions according to one or more criteria to find a candidate position for positioning of the first relay node to perform said relaying. The evaluation of a respective candidate position of said at least one of said one or more candidate positions is based on measurements performed by the first measurement node on both a first relay-link and a first access-link when positioned in the respective candidate position. Said first relay-link corresponds to a communication link between said first measurement node and the first radio network node. Said first access-link corresponds to at least one communication link between said first measurement node and said one or more first wireless devices in said certain area.

According to a second aspect of embodiments herein, the object is achieved by a computer program comprising instructions that when executed by one or more processors causes a controller node to perform the method according to the first aspect.

According to a third aspect of embodiments herein, the object is achieved by a carrier comprising the computer program according to the second aspect.

According to a fourth aspect of embodiments herein, the object is achieved by one or more devices for supporting positioning of a first relay node for relaying communication between a first radio network node of a wireless communication network and one or more first wireless devices located in a certain area. The one or more devices are configured to initiate to move a first measurement node along a path comprising one or more candidate positions for positioning of the first relay node. The one or more devices are further configured to initiate to evaluate at least one of said one or more candidate positions according to one or more criteria to find a candidate position for positioning of the first relay node to perform said relaying. The evaluation of a respective candidate position of said at least one of said one or more candidate positions is based on measurements performed by the first measurement node on both a first relay-link and a first access-link when positioned in the respective candidate position. Said first relay-link corresponds to a communication link between said first measurement node and the first radio network node. Said first access-link corresponds to at least one communication link between said first measurement node and said one or more first wireless devices in said certain area.

Thanks to embodiments herein, and that both the relay-link(s) and access-link(s) are measured and taken into in evaluation of candidate positions, more suitable candidate positions can be found compared to if for example only the relay link is considered. The way candidate positions are utilized and evaluated also allows for finding suitable candidate positions faster over time. It is thereby possible to more efficiently employ relay nodes to accomplish better capacity and/or quality of service in wireless communication networks. Especially if there are certain area(s) in the network where a radio network node has difficulties to directly by itself serve wireless devices with sufficient capacity and/or quality of service.

BRIEF DESCRIPTION OF THE DRAWINGS

Examples of embodiments herein are described in more detail with reference to the appended schematic drawings, which are briefly described in the following.

Figure 1 is a block diagram schematically depicting a wireless communication network in which embodiments herein may be implemented and utilized.

Figure 2 is a block diagram schematically depicting a simplified example with three exemplary candidate paths

Figure 3 is a block diagram schematically depicting a simplified example with another exemplary candidate path that is dynamically determined.

Figure 4 is a block diagram schematically depicting an example of a candidate path based on previous measurements.

Figure 5 is a combined signalling diagram and flowchart for describing and discussing some examples and embodiments herein.

Figure 6 is a flowchart for describing and discussing embodiments that involve previous measurements. Figure 7 is a combined signalling diagram and flowchart for describing and discussing some examples and embodiments herein, specifically regarding previous measurements that may be performed with purpose to explore and find suitable and/or potential candidate positions for later use.

Figure 8 is a flowchart schematically illustrating embodiments of a method, performed by one or more devices or nodes, according to embodiments herein.

Figure 9 is a schematic block diagram for illustrating embodiments of how one or more devices or nodes may be configured to perform the method and actions discussed in connection with Figure 8.

Figure 10 is a schematic drawing illustrating some embodiments relating to computer program(s) and carriers thereof to cause one or more network nodes to perform the method and related actions discussed in connection with Figure 9.

DETAILED DESCRIPTION

Throughout the following description similar reference numerals may be used to denote similar elements, units, modules, circuits, nodes, parts, items or features, when applicable. Features that appear only in some embodiments are, when embodiments are illustrated in a figure, typically indicated by dashed lines.

Embodiments herein are illustrated by exemplary embodiments. It should be noted that these embodiments are not necessarily mutually exclusive. Components from one embodiment may be tacitly assumed to be present in another embodiment and it will be obvious to a person skilled in the art how those components may be used in the other exemplary embodiments.

As part of the development of embodiments herein, the situation and problems indicated in the Background will first be further elaborated upon.

A problem when it comes to network densification is where to best place the new nodes. It may be labor-intense manual work and hence both time consuming and costly. If it is based on measurements or models of propagation, it is also sensitive to errors in those. Further, if the conditions change, the procedure must be repeated. In the prior art mentioned in the Background, it is disclosed a scheme designed to optimize the locations of drone cells to cover an area. There, as well as for example in “Optimal 3D U AV Base Station Placement by Considering Autonomous Coverage Hole Detection, Wireless Backhaul and User Demand", Shahriar Abdullah Al-Ahmed, Muhammad Zeeshan Shakir, and Syed AH Raza Zaidi, JOURNAL OF COMMUNICATIONS AND NETWORKS, VOL. 22, NO. 6, DECEMBER 2020, the focus is only on the link between the Unmanned Aerial Vehicle (UAV) and UE(s), not covering the required backhaul from the UAV to the network.

It appears likely that use of UAV based small cell may become a solution for the future, at least to supplement stationary solutions. However, for this to be beneficial, there is needed methods for supporting or even securing high quality regarding the complete link from UE to network. Further, it is realized that the solution should be automized to as great extent as possible.

With the above in mind, a solution for relay node placements that can be performed automatic, in other words that the solution at least supports automation, is sought for. Such solution would achieve the object set forth above.

Embodiments herein relate to such solution and are based on realization of the following:

- with a relay node involved the signal path between the network and the UE is made up of at least two links (an relay link between the network and the relay node and an access-link between the relay node and UE),

- the quality of the total path depends on all of the included links, and

- the position of the relay node affects both its relay-link and access-link.

In short, embodiments herein are based on an idea where a mobile relay-node, or multiple such relay nodes, are moved to and/or over candidate positions while monitoring the quality of both the relay-link and the access-link, followed by placing the relay-node in a position that, based on what has been monitored, that is, has been measured, maximizes, or reaches a targeted level of, combined link quality. Quality can for example be measured by data rate, delay, path gain or a combination thereof.

As used herein, candidate position is used as name for a position for possible position of a relay node for relaying communication.

Information, for example from an map, 3D, pure 2D or 2D supplemented with 3D info, regarding an area can be utilized to find potentially suitable positions for the relay node. The relay node(s), preferably in the form of a UAV, may additionally have sensors that can provide and/or supplement 3D information about the area, for example regarding high buildings, areas with indication of poor coverage, etc. 3D information can this way be improved over time and for example stored in association with an existing 2D or 3D map that will improve over time with useful information about where a relay node can be placed, and the information can of course be shared between relay nodes.

Before discussing a solution and embodiments thereof, a wireless communication network and nodes will be disclosed and in which embodiments herein may be implemented and utilized.

Figure 1 is a block diagram where the lower part schematically depicts a wireless communication network 100 in which embodiments herein may be implemented and utilized. The upper part of the figure exemplifies a situation where the wireless communication network 100 utilizes a first relay node 115 for serving wireless devices, here exemplified by a first wireless devices 120-1 , 120-2.

The wireless communication network 100 may comprise a Radio Access Network (RAN) 101 part and a Core Network (CN) 102 part. The wireless communication network 100 may be a telecommunication network or system, such as a cellular communication network that supports at least one Radio Access Technology (RAT), e.g. LTE, or 4G, and/or 5G, New Radio (NR) based systems in general, and, including also further generations beyond 5G, such as 6G, etc.

The wireless communication network 100 comprises network nodes that are communicatively interconnected. The network nodes may be logical and/or physical and are located in one or more physical devices. The wireless communication network 100, typically the RAN 101, comprises one or more radio network nodes, for example a first radio network node 110 as shown in the figure. The first radio network node 110, such as a eNB or gNB, may be or comprise radio transmitting and/or receiving device(s), such as base station(s) and/or controlling node(s), that control one or more radio transmitting and/or receiving devices. The first radio network node 110 is configured to serve and/or control and/or manage one or more wireless communication devices, e.g. said first wireless devices 120-1 and 120-2, and or one or more relay nodes, such as a first relay node 115. In general, a radio network node may provide one or more radio coverages, e.g. corresponding to one or more radio coverage areas, i.e. radio coverage that enables communication with one or more wireless devices that it serves and/or one or more relay nodes that it may control and/or manage. For example, there may be a serving area 125 provided by the first radio network node 110 for serving the first wireless devices 120-1 , 120-2- and/or communicating with the first relay node 115. The serving area 125 may correspond to a radio coverage area with radio coverage provided by the first radio network node 110 and which radio coverage is supported or supplemented by means of the first relay node 115.

The first wireless devices 120-1, 120-2 are for communication with and via the wireless communication network 100, for example by being served by the wireless communication network 100 by means of one or more radio network nodes, e.g. the first radio network node 110 when within its radio coverage, for example when located in the serving area 125. Embodiments herein relates to situations when there is relay node such as the first relay node 115 involved and that relays communication between one or more wireless devices, such as the first wireless devices 120-1 , 120-2, and a radio network node, such as the first radio network node 110. Radio communication between a wireless device and a radio network node of the wireless communication network, with or without involvement of a relay node, typically takes part over one or more radio channels.

A wireless device as mentioned above is a wireless communication device and may correspond to a UE etc. as mentioned in the Background. Each radio coverage may be provided by and/or associated with a particular Radio Access Technology (RAT). A cell is a logical entity in which wireless devices are served through radio coverage. The serving area 125 may correspond a cell, such as a macro cell, or cells if there are several cells, for example provided by the first radio network node 110, that may have overlapping coverage for serving wireless devices in the serving area 125. The radio coverage may be provided simultaneously in a relatively large geographical area for serving of wireless devices in that area and/or by one or more radio beams, that simply may be named beams. As should be recognized by the skilled person, a beam is a more dynamic and relatively narrow and directional radio coverage compared to how radio coverage has been provided conventionally, and may be accomplished by so called beamforming. A beam is typically for serving one or a few wireless devices at the same time, and may be specifically set up for serving these. Such beam may be changed dynamically by beamforming to provide desirable coverage for the one or more wireless devices being served by the beam. There may be more than one beam provided by one and the same radio network node. The first relay node 115 may communicate with the first radio network node 110 and/or the wireless devices 120-1, 120-2 using beams if the involved RAT is using beamforming. As should be realized, embodiments herein are not dependent on a particular RAT.

The first relay node 115 may be used to improve, or even enable, radio coverage for one or more parts, or sub-areas, of the serving area 125 and thereby improve serving of wireless devices in these parts. Where such parts are located may be known in advance, that is, may be predetermined, and/or been determined from quality of communication between the first radio network node 110 and one or more wireless devices during normal operation without involving any relay node. For example based on that it during normal operation is detected that it is difficult or impossible to communicate with sufficient quality when wireless devices are in certain parts of the serving area 125. More generally, it may be known from experience and/or from infrastructure and/or geographical information where such “difficult” parts of the serving area 125 are located. For example, there may be one or several building or other structures between the radio network node 110 and some part(s) of the serving area 125 that makes it difficult or impossible for the first radio network node 125 to directly provide radio coverage to such part(s) and/or, if wireless device(s) are located in such part(s), that makes it difficult or impossible to serve wireless device(s) with a sufficient quality of service. There are two exemplary such parts of the serving area 125 shown in the figure, in the form of a first area 152a and a second area 152b. The areas 152a-b are drawn as sub-areas of the serving area 125. In terms of radio coverage it may be so that the radio network node 125 cannot directly provide sufficient radio coverage for serving one or more wireless devices in the first area 152a and/or the second area 152b. The first wireless device 120-1 is in the shown example located in the first area 152a and in the second area 152b that overlaps with the first area 152a. The first wireless device 120-2 is in the shown example located in the second area 152b.

Further, there are two exemplary buildings 150a and 150b shown in the figure to illustrate that radio coverage directly from the radio network node 110 may be screened, shielded and/or disturbed in some way due to that the buildings are in the way for direct radio coverage by the radio network node 110 and makes it difficult for the radio network node 110 to itself directly serve wireless devices in these areas. The first relay 115 node is shown between the two buildings and it is realized that if the first radio network node 110 can utilize and communicate via the relay node 115, it is possible to via the first relay node 115 provide better radio coverage and to better serve the wireless devices in the areas 152a-b.

Said first relay node 115 is preferably comprised in or is in the form of an UAV, often referred to as a drone, that may be fully or partly controlled by the wireless communication network, e.g. by or via the first radio network node 110, and/or be fully or at last partly autonomous. To what extent the first relay node 115 itself performs actions relating to embodiments herein, differs between embodiments.

In some embodiments herein, the first relay node 115 is, instead of an UAV, an unmanned land based vehicle, e.g. corresponding to a car. In any case, the first relay node 115 should have a capacity to automatically move and change position in relation to the first radio network node 110 and one or more wireless devices. Except for functionality more directly relating to embodiments herein, the relay node 115 may have conventional autonomous functionality for a UAV or autonomous car, such as collision avoidance, emergency stop and/or emergency landing, other security functions, auto-navigational functionality, return-to-base functionality in case of certain events and/or errors, etc. Although not necessary it may for practical reasons be advantageous to have a base of the first relay node 115 near or at, such as co-located with, the first radio network node 110. The first relay node 115 should at least start from a location with stable communication with, and preferably within line of sight of, the radio network node 110.

When the first relay node 115 is involved in communication between the first radio network node 110 and the first wireless devices 120-1, 120-2, the radio communication between the first radio network node 110 and the first relay node 115 is taking place over a relay-link 122 and the radio communication between wireless device(s) and the first relay node 115 is taking place over access link(s). For example, as shown in the figure, there is a first access-link 124-1 between the wireless device 120-1 and the first relay node 115 and a second access-link 124-2 between the wireless device 120-2 and the first relay node 115. When a relay node is involved there is thus communication links to and from the relay node that correspond to a relay link and one or more access links. Further, radio network nodes of the wireless communication network 100, such as the first radio network node 110, may be communicatively connected, such as configured to communicate, over, or via, a certain communication interface and/or communication link with each other and/or other network nodes.

The wireless communication network 100, or rather the CN 102, typically comprises one or more core network nodes. These may be communicatively connected to each other and other network nodes, such as configured to communicate, over, or via, a communication interface and/or communication link, with radio network nodes of the RAN 101 , e.g. with the first radio network node 110.

The figure also shows a further node 141 and a further network 140, as examples of one or more such further nodes and networks. The further node 201 may be located outside the wireless communication network 100, i.e. be an external node, as indicated in the figure, or alternatively (not indicated in the figure) be comprised in the wireless communication network 100 and thus be a network node thereof, such as a management node thereof. Likewise, the further network 140 may be located outside the wireless communication network 100, i.e. be an external network, as indicated in the figure, for example corresponding to a so-called computer cloud, often simply referred to as cloud, that may provide and/or implement services and/or functions for and/or relating to the wireless communication network 100, and for example including control and/or management of the relay node 115. The further network 140 may alternatively (not indicated in the figure) be comprised in the wireless communication network 100 and thus e.g. correspond to a subnetwork thereof. It is implied that a network, such as any one of the wireless communication network 100 and the further network 140, comprises communicatively interconnected network nodes. The further network 140 and further network node 141 may in principle be any network and network node communicatively connected to the wireless communication network, e.g. to support it in some way. The further node 141 may be comprised in the further network 140 and may then be referred to and be example of a network node of the further network 140.

The RAN 101 may, at least partly, be and/or may at least partly be implemented as, and/or may comprise, an open RAN, such as O-RAN specified by the O-RAN Alliance, and for example comprising a lower layer split (LLS), such as according to O-RAN Open Fronthaul specifications. The radio network node 110, e.g. gNB, may comprise one or more Open Radio Units (O-RUs), and in some embodiments also a O-RU Controller, while in other embodiments, another network or node comprise the O-RU Controller, e.g. the further node 141 or further network 140, e.g. a computer cloud. In these embodiments the O-RU Controller may be implemented as function in the cloud. In some embodiments the first relay node 115 may correspond to or comprise a O-RU and/or at least partly be controlled by an O-RU Controller.

Attention is drawn to that Figure 1 is only schematic and for exemplifying purpose and that not everything shown in the figure may be required or relevant for all embodiments herein, as should be evident to the skilled person. Also, a wireless communication network or networks that correspond(s) to the wireless communication network 100, will typically comprise several further network nodes, such as further radio network nodes, e.g. base stations, network nodes, e.g. both radio and core network nodes, etc., as realized by the skilled person, but which are not shown herein for the sake of simplifying. There may for example be multiple radio network nodes and serving areas that are controlled and that may cooperate and that the first relay node 115 can be used with etc.

Note that in some embodiments described in the following, a measurement node corresponding to the first relay node 115 is utilized to perform, for the relay node 115 relevant measurements, on relay-link(s) and access-link(s), but without having any relay functionality as such of its own and/or not actively participating in relaying. Those embodiments are instead about to measure and evaluate positions for possible later use by a relay node, such as the relay node 115, to relay communication. Such measurement node may operate in the wireless communication network correspondingly as or instead of the first relay node show in Figure 1, but without having any, or having inactivated, relay functionality.

Figure 2 is a block diagram schematically depicting a simplified example with three exemplary candidate paths, more particularly first, second and third candidate paths 216a-b. Respective path comprises a number of candidate positions for positioning of the first relay node 115 and from there perform measurements both on the relay-link and the access-link(s). Respective candidate position is evaluated based on the measurements from the respective candidate position. Hence, evaluation comprises a combined link quality regarding both the relay and access links. The figure and example will be used to explain and discuss certain aspects regarding embodiments herein relating to candidate paths and positions. The figure is based on part of the wireless communication system 100 as shown in Figure 1 and is drawn in a 2D coordinate system X-Y that may correspond to geographical coordinates, such as of a map. The first candidate path 216a has 5 candidate positions 218a-1..218a-5, although only some are explicitly labeled with numbers in the figure. The second candidate path 216b also has 5 exemplary candidate positions 218b-1..218b-5, with only some explicitly labelled with number in the figure. The third candidate path 216c has 5 exemplary candidate positions 218b-1..218b-5, but only some are explicitly labelled with numbers in the figure.

There being 5 candidate positions per candidate path is of course just an example and the same number being used for the three paths is to facilitate comparison. In practice there can be any number of candidate positions along each candidate path and do not need to be the same number on each. Variants and different types of candidate paths and candidate positions are further discussed below. What is shown and discussed in relation to Figure 2 is just to introduce some basics that are underlying embodiments herein.

To illustrate that the first relay node 115 is to be moved along candidate paths, the first relay node 115 is indicated as three examples with reference numerals 115a-c at the end of respective candidate path. Respective one of first relay nodes 115a-c thus corresponds to the first relay node 115 and the letters a-c just indicate candidate path association. Similarly, there are some relay-links and access links shown with numbers in the figure. There is shown a relay-link 122a between the first relay node 115a and the radio network node 110, and access-link 124a between the first relay node 115a and the first wireless device 120-1. Further, there is shown a relay link 122b between the first relay node 115b and the radio network node 110, an access-link 124b-1 between the relay node 115b and the wireless device 120-1 , and an access link 124b-2 between the relay node 115b and the wireless device 120-2.

Note that the respective first relay node 115, 115a-c shown in Figures 2-3 is also indicated as a respective second relay node 215, 215a-c in the figures, that the first radio network node 110 is also indicated as a second radio network node 210 and that the first wireless devices 120-1, 120-2 are also indicated as second wireless devices 220-1 , 220- 2. This is just in order to facilitate explanation of some embodiments further below where candidate positions are based on and/or evaluated based also on previous measurement that may have been performed in the past from the same candidate position by another node, such as the second relay node 215 that may be the first relay node 115 but at an earlier point in time, or another, but corresponding relay node, or a corresponding measurement node that do not have relay functionality. Measurements are performed on one or more second wireless devices in the same area. Some or all of the second wireless devices 220-1 , 220-2 may be the same as the first but are typically other wireless devices than the first wireless devices 120-1 and 120-2, which is indicated by the different numbering 220-1 , 220-2. Further, although the drawings due to this appear to indicate that the second wireless devices 220-1., 220-2 are in the same positions as the wireless devices 120-1, 120-2, this is not required or realistic. This being the case in the figure is just a result from that the same wireless device symbols are used in order not to clutter the figure with even more details. In case of utilizing previous measurements it may suffice that these measurements were made from the same candidate position on wireless device(s) in the same area, for example the areas 152a-b.lt may even be so that another, second, radio network node 210, may have been used for the previous measurements if it is sufficiently similar to the first network node 110 in relevant aspect(s) in addition to being at the same location. Previous measurements etc. are further commented below.

Some example scenarios will next be discussed with reference to Figure 2 to explain by example the concept of candidate paths and positions that embodiments herein are based on.

Example scenario A

It is here assumed that it has been decided to improve communication for the first wireless device 120-1 that is served in an area associated with the radio network node 110, such as the serving area 125, using the first relay node 115, or at least that it has been decided to perform measurements on the first wireless device 120-1 in the first area 152a to find out if the first relay node 115 can improve its quality of service and/or quality of service regarding the first area 152a. The decision may be based on that the first wireless device 120-1 , or group of wireless devices that it belongs to, is experiencing or will likely experience quality of service that it less than entitled to and/or that the wireless communication network 100, e.g. via the radio network node 110, has measured or in some other way has got indication, for example based on location, that it is not, or will soon not be possible, to serve the wireless device 120-1 , or the group, with sufficient quality of service.

The first area 152a may correspond to an area where the first wireless device 120-1 or group is known to be located and/or may likely stay in for a period of time. The first area 152a may be thus a known area, that is, predetermined area, where it is known to be difficult to directly serve wireless devices by the radio network node 110 with a sufficient quality of service. Location of the wireless device 120-1 , or group, in this area, or some indication that it is about to move into the area, may trigger said decision, and/or it may be triggered by indication that quality of service in communication with the first wireless device 120-1 , or group, is not sufficient or is deteriorating so that it soon may not be sufficient.

See further below for more details and examples of information that can be used to decide when to use a relay node to improve communication and for which wireless device(s).

Following the decision, the first relay node 115, in this example the example first relay node 115a, is moved towards the wireless device 120, for example towards its known, or its last, or estimated position, or just simply towards the first area 152a, along a first candidate path 216a, in the shown example a straight path but this is just an example, while avoiding obstacles along the way for example using conventional such functionality of UAVs. In general, a candidate path may be predetermined, e.g. be based on or correspond to a previously determined candidate path and/or positions, for example for a similar situation and/or a candidate path and/or positions determined for the first area 152a, and/or may be based on geographical and/or infrastructure information about the area of concern and/or knowledge of location of the first area 125a. Alternatively or additionally, the candidate path may have been, or is determined more dynamically. A more dynamic way of determining candidate path is separately discussed below. In the present example scenario, it is assumed that the first candidate path is straight as shown in the figure, towards the first area 152a and taking into account geographical and/or infrastructure information, 2D and/or 3D, predetermined and/or determined through measurements along the say, such as regarding the building 150a, to avoid collision or other real or potential dangers. Additionally or alternatively it may be taken into account what will facilitate communication with the wireless device 120-1 and the radio network node 110, for example avoiding to move in directions where radio communication quality over the relay and/or access links are getting below some critical limit, at least regarding the relay-link to make sure communication with the network is sufficient. In some embodiments, as further discussed below, the relay node evaluates its relay-link and access-link when moving along the candidate path and may determine where to move next based on the evaluation. In any case, along the candidate path 216a, the relay node will at certain positions corresponding to the candidate positions along it, perform measurements on the access-link and the relay link, with evaluation based on these measurements. More details and examples regarding said evaluation follows further below but basically it is about to find out if the communication with the first wireless device 120-1 is sufficiently improved or not when the relay node is in a candidate position. The measurements may be performed during movement of the relay node in case measurements can be performed quickly and stable enough, or the relay node 115 may stop at each candidate position, for example hover or even land, and perform the measurements. Where and/or how to select candidate positions to use is further discussed below as well. In the shown example it is assumed that the relay node starts from the position of the radio network node 110, with the 5 circles indicating candidate positions 218a-1..218a-5 along the candidate path 216a in ascending order. It may be so that in the first three candidate positions, ending with candidate position 218a-3, both regarding the access link and relay link experiences deterioration according to the measurements due to that the relay node 115 moves away from the radio network node 110 and move into worse positioning in relation to the building 150a for communication with the first wireless device 115a. However, at the 4^th candidate position 218a-4 it may be so that the building 150a does not disturb communication any longer, but evaluation based on measurements may still not be considered good enough for some reason until the relay node is in the 5^th candidate position 218a-5 where it is considered to be sufficient quality of service. The relay node 115a may then stay in this candidate position and participate in serving of the wireless device 120-1 by relaying. At the same time it may also relay communication for some further wireless device(s) in the first area 152a, in need and/or entitled for communication over via the first relay node 115.

Example scenario B

Another example scenario with reference to Figure 2. Focus is only on what differs compared to Example scenario A to avoid repeating some information. In this example there is a group of wireless devices exemplified by the first wireless device 120-1 , 120-2 located in the second area 152a. The candidate path used in this example is the candidate path 216b that, in the figure just as the other candidate paths, is shown from “above”, is straight aiming between the buildings 150a-b representing known obstacles and/or aiming towards the middle of the second area 152b and/or between the first wireless devices 120-1 , 120-2. The measurements performed by example relay node 115b from candidate positions 218b along the candidate path 216b are thus on both the access-links 124b-1 , 124b-2 and the relay-link 122b and take all these links into account in the evaluation. A sufficient improvement may for example have occurred according to evaluation based on measurements from the candidate position 218b-5.

Regarding the position and of and how the second area 152b extends it would make less sense to use the candidate path 216a that is directed towards, and may have been predetermined, for the first area 115a, although this candidate path of course could have been used also for the second area 152b but then may have not succeed to improve communication sufficiently for the wireless device 120-2 in any of its candidate positions, including candidate position 218a-5.

Example scenario C

This is an example with yet another candidate path 216c with candidate positions 218c that may be used to measure from using the relay node 215 regarding any one of example areas 152a-b and/or wireless devices 120-1 , 120-2, but where the result would not be any candidate position as good as in the example scenarios A-B regarding the first area 152a with wireless device 120-1 or the second area 152b with wireless device 120-2. The result from evaluation may be that none of the candidate positions 218a are sufficiently “good” to be used. If all three candidate paths 216a-c in Figure 2 with the respective candidate positions to measure from and evaluate, it is realized that it likely would be candidate position 218a-5 that would be best for the first area 152a and candidate position 218b-5 that would be best for the second area 152b. These two candidate positions and possibly also the measurement results as such may be stored and used later regarding the same area, for example be used and included in a new candidate path when the first relay node 115, or for example another corresponding to the second relay node 216, are to be used regarding the first area 152a and/or second area 152b. Such already known “good” position may be used as a first attempt.

Information about all or some candidate positions that have been measured, including for example measurement result and/or evaluation results, may be stored in association with their position information, for example coordinates corresponding to map and/or visual information, for example images, of the proximity of candidate position to be able to facilitate positioning later in the same position and/or to be able to identify changes that may have occurred and that may affect re-positioning. This way previous information regarding position, measurements data and/or evaluation may be (re)used later, for example in order to retry and/or reuse previously “good” candidate position and/or evaluate a candidate position taking into account also how it has performed in the past for example regarding wireless device(s) in the same area.

If a map is used, it may both be used to in advance to determine candidate positions and/or candidate paths to use, as well as to indicate candidate positions that have been used and their status, such as based on result from previous evaluations, for example according to some evaluation grouping, such as “poor”, “good” or “acceptable” according to some criteria, and/or if the candidate position successfully have been used in the past by a relay node to serve wireless devices successfully. The stored information about candidate positions, for example measurement result and/or result from evaluation, may also be associated with and for example stored with the time when the measurements were performed and/or information about a traffic situation of relevance that may have been present when the measurements were performed.

The three candidate paths 216a-c in Figure 2 may be part of a movement pattern, such as flying pattern, that may be a candidate path covering a larger area. This may be of particular interest to begin with if a new area is being investigated whereby many candidate positions may be of interest to cover, be measured and evaluated. Such path may be formed based on geographical and/or infrastructure information, such as from map information, at least get some candidate positions to start from and get measurement result from to begin with.

Furthermore, in this situation and/or for a “new” area for relay node placements, the measurements may be performed on wireless devices that purposedly have been placed at various locations and with certain movement patterns that may be considered relevant, for example based on traffic information regarding wireless devices of real users. This may also be the case if measurements are to be performed when there are no or few real users present where it is desirable to measure, such as during night time, and/or that can be used for measurements. It is also possible to use another remotely controlled and/or at least partly autonomous mobile node, for example UAV, that act as wireless device to perform measurements on and that can be configured to send suitable reference signals, which may be beneficial in some situations compared to using more conventional wireless devices that may not be available and/or controllable to a sufficient extent. In any case, the result from such, for example first, measurements and evaluation based on the measurements for an area will result in some candidate positions that are likely better in general than others. Such, likely better, candidate positions may be included in and form new candidate paths, etc, so there will be found better and better candidate positions and candidate paths for the area.

Note that the measurements performed are such relevant for evaluation of a position for use by a relay node, such as the relay node 115, that itself may perform these measurements, but the measurements as such do not require relaying to be active and the measurements are thus typically not required to be performed by a node with relay functionality. Hence, above and in other examples herein, although the node performing the measurements may be the relay node 115 with relay functionality, this functionality need not be active, and it may even be beneficial that it is not active, until a sufficiently good candidate position has been found and a relay node is positioned in that candidate position and from there be relaying.

Figure 3 is a block diagram schematically depicting a simplified example with an exemplary candidate path 316. The figure exemplifies how a candidate path and candidate positions thereof can be determined dynamically. The view is a “side” view to illustrate that the principle also works with obstacles having a height, such as a high rise building, exemplified by building 350 in the figure, that could correspond to any of the buildings 150a-b. However, it should from the following be realized that the principle works in all three dimensions.

In the shown example it is assumed that the first relay node 115 starts from the location of the first radio network node 110, such as a gNB, but the principle works also with other starting points. The first relay node 115 starts to move in a determined initial direction 317 towards the wireless device(s) that the relay node shall perform measurement on from candidate positions, or towards an area, such as any one of the areas 152a-b, that the wireless device(s) is/are located in. The wireless device(s) is here represented by a first wireless device 120 that may correspond to any one of the first wireless devices 120-1 , 120-2 in the previous examples. The initial direction may be straight and may correspond to a direction corresponding to the direction of for example the first candidate path 216a. For example, the initial direction may be determined from Sounding Reference Signals (SRS) or Pre-coding Matrix Indicators (PMI), as further discussed below, or similar signals that may be available for the wireless device(s) in question. The first relay node 115 moves in the initial direction and performs measurements on both the relay-link and access link(s) from candidate positions along the way, for example from candidate positions 318-1 and 318-2 that are part of a candidate path 316 that is dynamically formed from how the relay node 215 travels. In embodiments based on this example, the candidate positions may be spaced apart with predetermined travelled distance, or ground distance, or distance in travel time so there will be candidate positions with suitable distance between them. Note that there is no need with equal distance between candidate positions although this may be convenient and/or be the case in practice, at least if candidate positions are not predetermined. At a certain candidate position, in the example assumed to be the candidate position 318-2, the relay node 315 may no longer be able to measure on the relay-link and/or the accesslink, or the measurements may be too weak or poor, and/or the evaluation of the measurements regarding both the relay and access links indicate a too poor or not good enough position according to some one or more criteria, and/or since the relay node 315, for example sensors thereof, has detected that it cannot or should not continue in a present travel direction, such as due to physical object blocking the way. The candidate position 318-2 may thus be considered a temporary stop position and/or direction change position. In the shown example the problem may be with the relay-link due to that the relay node 21 is too close to a building 350 that blocks signals to/from the wireless device 120. Another or additional reason for the relay node 215 to stop at a certain candidate position or other position along the candidate path may be that it detects a physical obstacle in the way, for example using conventional sensors used in drones and/or cars with autonomous navigation and/or collision avoidance. In any case, when experiencing a temporary stop position, such as at the candidate position 318-2, the relay node 115 may start to move in a suitable, for example predetermined, pattern 319-1 that become part of the candidate path 316 and is around and/or in the vicinity of the candidate position 318-2. For example, the relay node 315 may fly in a 3D pattern that may but not need to correspond to a sphere as indicated in the figure and perform measurements at spaced apart candidate positions along the way, thereby performing measurements from further candidate positions around said candidate position 318-2, including for example candidate position 318-3. Measurements are performed from the candidate positions along the pattern 319-1 and are evaluated. Some of these candidate positions will be better, best, or sufficiently good according to some one or more criteria that may be predetermined and/or in relation to previous measurements. It is in the example assumed that the candidate position 318-3 is such candidate position. The relay node then change direction and move in a direction corresponding to the direction from the candidate position 318-2 towards the candidate position 318-3, that is, in a new, typically straight, direction further extending the candidate path 316 and with new candidate positions along the way that measurements are performed from etc. In the example, it is realized that that there is likely improvement at least for the access-link based on measurements from candidate position 318-7 and 318-8, but none of them may be sufficiently good or it is just of interest to find out if there may be another yet better candidate position. The relay node continues in the direction it travels in and in next candidate position 318-9 it is in the example assumed to be some deterioration according to the measurements and/or the evaluation, compared to the previous candidate position 318-9 and/or that is considered significant to trigger a change, the rely mode may travel back to and start to move in a pattern 319-2 around or in the vicinity of the candidate position 318-2, that is, similar to as before but around the last “better” or sufficiently good candidate position. The pattern 319-2 may correspond to the pattern 319-1 or may be different than the pattern 319-1 , for example a predetermined other pattern for example associated with what has triggered the situation. In any case, the principle is the same with how this pattern is used, measurements are performed from at least one candidate position but likely many along the pattern 319-2, evaluations based on the measurements are performed, the best candidate position or the first one that is considered sufficiently good, is selected, which in the example is assumed to be candidate position 318-13. The relay node, in a corresponding manner as for the pattern 319-1 , starts to move in a new direction corresponding to the direction between the candidate positions 318-8 and 318-13. In the example it is assumed that the next candidate position in this direction, namely candidate position 318-14 is considered sufficiently good and/or an end position of the candidate path 316. For example, the candidate position 318-14 may be considered sufficiently good for improving quality of service for the wireless device 120 when serving the wireless device via the relay node 115 from this candidate position. If the wireless device 120 corresponds to a real users that the quality of service are to be improved for by means of the first relay node 115, the relay node may stay in this position and participate in serving the wireless device 120 through relaying as long as it is needed and/or possible and/or beneficial. If the first wireless device 120 is a device that has been located just for measurement to find and evaluate candidate positions, that is, for purpose as mentioned above, the relay node 115 may return to base, typically same as its start position, after the candidate position 318-14 has been identified, or continue to measure from and evaluate further candidate positions, for example after the first wireless device has moved to a new position. As indicated already above, information that indicates or identifies the candidate position as “good” should be stored in association with the position for later use, but it may be beneficial to store also additional information and/or information about also other, or even all, candidate positions that have been measured and evaluated, simply to collect as much data as possible that has been made available.

As already indicated in the foregoing, direction of radio signals may be used to direct a relay node such as the relay node 115 towards a wireless device or devices in an area. This, however, may require that the serving site is equipped with some type of advanced antenna array (AAS), which may not always be the case. A map, such as a digital map, for example of a city, in 2D or even better in 3D, may be used to alternatively or additionally determine directions and at least parts of candidate paths to use.

Problem areas, such as for example the first and second areas 152a-b, may be found through simulation that can predict likely problem areas of a serving site, for example in the serving area 125. When such problem are has been predicted, the relay node may be sent out, for example from the radio network node 110 serving the serving area 125, towards the predicted problem area while remaining within sufficient coverage of the radio network node 110. Pointing direction and/or beampattern are typically known parameters for a serving site and can be utilized. When starting to move towards such problem area, a procedure as discussed above in relation to Figure 3 may be used, possibly in combination with some parts of the candidate path predetermined based on map information.

Over time, as should be realized, some candidate positions for example initially found through measurements and evaluation based on what has been discussed above in relation to Figures 2-3 will likely turn out to be more effective and/or useful for improving communication in certain areas, for example for the first area 152a. In such situation and area, when it has been decided to use a relay node to improve quality or service for some wireless device(s) in the area, the relay node can directly move to and first measure from and/or attempt using such known “good” candidate position. If evaluation of measurements from this candidate position results in that the candidate position despite its “history” as a “good” candidate position does not provide sufficient improvement, the relay node 115 may move away from and along a candidate path that thus starts from the previous “good” candidate position and may include also other known previous “good” position(s) and other new candidate positions as well. In this way, iterative improvements regarding candidate paths and positions regarding an area, such as the first area 152a, are possible.

Moreover, a candidate position that according to evaluation corresponds to a sufficient improvement, for example is “good” or “acceptable” according to some one or more criteria, possibly with some margin, may be attempted to be slightly adjusted and tested as another, new, candidate position, such as to see if it further improves and/or if this provide some other advantage, for example that it thereby will be possible to land and/or park and/or charge the relay node, on a building roof and/or wall and/or wall attached platform. Such slightly adjusted “good” candidate position or an area, such as the first are 152a, may be planned and prepared in advance, for example first providing a platform, test it as a new candidate position later, and if it turns out to be good and useful, next provide it also with charging means for the relay node 115, etc.

Figure 4 is a block diagram schematically depicting an example of a candidate path 416 with candidate positions 418-1..418-6 based on previous measurements, here particularly involving candidate positions that based on previous measurements have been evaluated as “good” and/or that a relay node has been positioned in such candidate position and successfully therefrom, by relaying, been participating in serving wireless device(s) in the same area, in the example represented by the first area 152a. For example, the candidate path 416 may include candidate positions 418-6 and 418-3 that may correspond to candidate positions 218a-5 and 218b-5, respectively, that previously was evaluated as “good” positions for serving wireless devices in the first area 152a, such as discussed for example scenario A above in connection with Figure 2. It may also be so that the candidate position 218a-5 thereafter have been used by a relay node, for example the relay node 215, that by relaying has participated in successful serving of one or more wireless devices, which may further strengthen the position as “good” and worth to try again. Assume it has now, at some later occasion, been decided to use a relay node, that may be the same first relay node 115 or another relay node 415, in the serving of another wireless device, or devices, such as a wireless device 420, in the first area 152a, or associated area, for example a neighbouring or overlapping area as the second area 152. A candidate path may then be formed to, or it may be made sure that a candidate path. That partly may be formed dynamically as described above, will comprise such known “good” position(s), including for example said candidate positions 418-6 and 418-3. Any of these candidate positions, for example the one considered most likely to be the best for the area, such as the candidate position 418-6, may be attempted first, or even be the only one tried if it turns out to still be “good” and provide sufficient improvement when used, or it may be formed a candidate path, as indicated in the figure, that includes both previously “good” candidate positions, that is, according to previous measurements and evaluation, and new ones. For respective candidate position, both new and previous ones, it is performed measurements by the relay node, for example the relay node 415, on both the relay-link and the access-link(s) and which measurements thereafter are evaluated to determine if the relay node at the candidate position provides sufficient improvement or not. For example, the candidate positions 418-1, 418-2 and 418-4 may be additional, new, candidate positions located along the candidate path 416, for example located between previously known “good” candidate positions and/or that just along the candidate path 416 formed when the relay node is moving to a next known “good” position. Which candidate position that the relay node 415 may stay in and participate in the serving of the wireless device 420, may be determined by the evaluation of respective candidate position.

Figure 5 is a combined signalling diagram and flowchart for describing and discussing some examples and embodiments herein, and related actions.

The actions may be part of a method for or regarding positioning of a first relay node, exemplified in the following by the relay node 115, for example to improve communication for one or more first wireless devices, such as the first wireless device 120-1 and/or 120-2, collectively referred to as the first wireless device(s) 120 in the following for simplicity. The wireless device(s) 120 is located in a certain area, for example the serving area 125 and/or the first area 152a and/or the second area 152b. The communication is relayed by the relay node 115 between a first radio network node, exemplified in the following by the first radio network node 110, and said one or more first wireless device(s) 120.

The actions in the following are indicated in the figure to be performed by either or both of the first radio network node 110 and the first relay node 115. Some actions are better or may be preferred to be performed by either node but a lot of combinations are possible, as should be realized. In some embodiments, not indicated in the figure, also other nodes may participate in performing the actions, such as other nodes of the wireless communication network 100, or that are connected to it, such as the further network 140 and/or the further node 141.

Which one of the first radio network node 110 or other node of the wireless communication network, and the first relay node 115 that are performing the actions, or main part of the actions, may be determined by the degree of autonomy that is attributed the relay node 115 and/or its capacity. If the relay node 115 is mainly controlled by another node, e.g. by any one of the other mentioned nodes that may be involved in performing the actions, the relay node may perform only actions it needs to be involved in, corresponding to a minimal number of the total of actions. If on the other the first relay node 115 can and shall operate very autonomous and for example keep down communication with the network except for the relaying as such, it may perform a large extent of the actions itself, possible with some support from the network and for example to inform the network of results from actions, logging and/or storing, such as backing up information, for later use by the network and/or other relay nodes.

The actions below may be taken in any suitable order and/or be carried out fully or partly overlapping in time when this is possible and suitable.

Action 500

The involved nodes, the first radio network node 110 and the first wireless device(s) 120 and the first relay node 115 may be configured if and to the extent needed to be able to participate in and carry out the actions, e.g. regarding reference signals to be used to perform measurements on, although in some embodiments it is used reference signals that the wireless devices are already using in communication with the first radio network node 110, for example gNB. Anyhow, the present action may involve to configure the first radio network node 110 and/or the first wireless device(s) 120 to send reference signals that the first relay node 115 can measure on and link quality be estimated from. The present action may additionally involve to configure the first relay node 115 to listen to these reference signals.

Examples of reference signals that a radio network node, such as the first radio network node 110, may send or be configured to send and that can be used with embodiments herein, include Common Reference Signals (CRSs), Channel State Information Reference Signal (CSI-RS), and Synchronization Signal Blocks (SSBs), such as used in wireless communication networks based on 5G/NR, but similar or corresponding reference signals are present and are expected to be present also in prior and later generation wireless communication networks, as recognized by the skilled person. The radio network node may also set up an active session with the relay node if it for example is expected that the wireless device specific beamforming may have a significantly different coverage compared to cell-specific signals as mentioned above.

Examples of reference signals that a wireless device, such as the first wireless device(s) 120, may send or be configured to send and that can be used with embodiments herein, are Sounding Reference Signals (SRS), Demodulation Reference Signals (DMRS) and similar. The SRSs are known signals and may be detected by anyone even if not the intended receiver. Reference signals like this are often available in wireless communication networks, for example transmitted by wireless communication devices and/or radio network nodes.

The relay node, for example the first relay node 115, may in the present action be configured to listen to the relevant, for example configured, reference signals from the first radio network node 110 and first wireless device(s) 120.

Action 501

It is decided to use the relay node 115 to improve communication for the first wireless device(s) 120 in the certain area.

The decision may be taken by the wireless communication network 100 and/or node(s) thereof and is typically involving the first radio network node 110 but also other nodes of the network may participate. The first relay node 115 may take the decision, but may be no particular benefit with that since the information to trigger the decision typically must come from the network anyway and relate to some problems of serving the first wireless device 120 directly by the radio network node 110. Hence, the first radio network node 110 may at least initiate the decision. The decision may be based on information already discussed above, for example that the wireless device(s) is located in an area known to be problematic or are moving towards such area, and/or that the first radio network node 110 when directly serving the first wireless device(s) 120 considers that there are problems that may be improved or solved if a relay node is used. Another trigger for the decision may be that the quality of service for the wireless device(s) or user(s) thereof, gets below some limit or threshold, or are not good enough in relation to what user(s) of the wireless devices are entitled for, for example since they are entitled to a certain level of service, such as a certain guaranteed bandwidth and/or quality of service level.

Furthermore, it may be possible for an operator to trigger and/or take the decision manually. For example, if an operator is aware that a certain area will be crowded at a certain time in the future, for example due to a particular event, the operator may preemptively want to have relay node(s) suitably positioned, and for example in advance have made sure that candidate positions have been measured and evaluated for the area.

Additionally or alternatively, the decision may be based on evaluation of existing measurements by the first radio network mode 110 and/or the first wireless device(s) 120, without involvement of any relay node, on for example the macro cell, such as provided by the first radio network node 110 and that may have an at least theoretical coverage corresponding to the serving area 125. Through this it may for example be determined that first wireless device(s) 120 experiences received power, or throughput, lower than a predefined or predetermined threshold or threshold value. To be able to find out some information about where the first wireless device(s) 120 is/are located, e.g. if no location data and/or map information is available, existing previous measurements and data regarding the first wireless device(s) 120 in question may be analyzed and may provide indication of a direction from the first radio network node 110 towards where the first wireless device(s) is/are located. For example:

• The direction to wireless device(s) may be determined by spatial processing of SRS signal(s), for example based on oversampled Fast Fourier Transforms (FFTs) or other beam space transforms. Another possibility is to use some other tabular and/or Artificial Intelligence (Al) based method where a reported position of a wireless device may be connected through some reference signal, such as SRS and/or DM RS, fingerprinting. Training may be made through some drive tests with measurements or other measurements during deployment of a site.

• If/when no SRS signal(s) or information is available, or not useful, which may be the case for some coverage limited wireless devices, the radio network node may instead resort to codebook-based reports, where e.g. a PMI report may indicate a beam most preferred by the wireless device and that can be used to extract a direction.

Note that this action is about decision to use the relay node 115 for relaying, but this does not mean that the relay node is directly starting to relay communication and participate in serving of the first wireless device(s) 120.

Action 502

It is obtained a candidate path, or rather information identifying such path, for the relay node 115. The candidate path may be as discussed above and is for positioning of the relay when it is used for relaying the first wireless device(s) 120 in said certain area. The relay node 115 may obtain the candidate path from the network, receiving it from the first radio network node 110 or may obtain it by forming it, for example in any of the ways discussed above. Alternatively, any other of the nodes mentioned above for performing the actions may obtain the candidate path by forming it and/or receiving information about it.

Action 503

The first relay node 115 is moved along or according to, the candidate path. This action involves the first relay node 110 that either with direct knowledge of the candidate path, if it for example has obtained the candidate path it in Action 502, controls itself to move according to it, or is controlled by another node, for example by or via the first radio network mode 110, to follow the candidate path.

Acton 504

The first relay node 115 performs measurements on relay-link and access-link from candidate positions along candidate path. The one or more candidate positions along the candidate path, that is the positions to measure from, may be determined as discussed above, for example be predetermined, and/or determined dynamically, and/or with certain distance between consecutive candidate positions along the candidate path, even using partly random positions along the candidate path is possible. In some embodiments all or some of the candidate positions are determined by the network or node(s) thereof or connected to it, e.g. the first radio network node 110, and are then communicated to the first relay node,. Alternatively, if the first relay node is controlled, such as triggered, to perform the measurements at these positions, for example by and when a node(s) controlling the first relay node has been informed that the first relay node 110 is at a position that is, or shall be, a candidate position to measure from.

Action 505

The relay node 115 and/or node or nodes of the wireless communication network or node(s) connected to it, form, based on said measurements, link quality metrics for candidate positions, respectively, for both relay-link and access-link. Forming link quality metrics typically involves, and/or is a result from, estimating link quality from the measurements.

To be able to form quality metric directly and quickly from results of the measurements, without the need to communicate with the network and use communication bandwidth for it, it may be advantageous that the first relay node 115 performs this action, but in principle results from the measurements can be sent to node or nodes of the network or node(s) connected to it, and such node may thereafter perform the present action.

Said link quality metrics may be one or more of the following types: data rate, latency, path gain, Signal to Noise Ratio (SNR), Signal to Interference and Noise Ratio (SINR), received power, Block Error Rate (BLER), Reference Signal Received Power (RSRP) and Reference Signal Received Quality (RSRQ).

In some embodiments, the link quality metrics are based on several measurements by the first relay node 115 when positioned in the respective candidate position and this is then taken into account by the link quality metrics so they indicate stability over a period of time during which said several measurements for respective candidate position were performed. This is further discussed below.

The link quality metrics may be formed by computations for example according to conventional computations to compute and/or estimate corresponding quality metric in question from measurement on links to a wireless device and/or radio network node. Of course, the type of measurements that are performed may have been selected or determined in advance, that is, may be predetermined, so that a suitable and desirable type of link quality metric, such as any of the mentioned ones, are formed from the measurements.

In some embodiments, the link quality metrics comprising relay-link quality metrics and/or said one or more access-link quality metrics, are based on several same type of measurements by the first relay node 115 on the same link when positioned in a candidate position it performs measurements from. This may be done so that the formed link quality metrics indicate stability, at least over a period of time during which said several measurements for respective candidate position were performed.

With several same type of measurements per candidate position for some period of time per candidate position, the metrics can contain information and/or indicate stability and reliability over time, which often is important and may be more important than just knowing that a candidate can be good but perhaps only occasionally. Average for metrics mentioned above during the period of time can of course be formed and/or with some measure, e.g. variance, regarding spread or variability during the period of time. The metrics can then be weighed in relation to each other, for example in connection when forming a single metric,, or example by using a cost or score function, as mentioned below. For example, high spread in path-gain may be considered unreliable and not be preferred over a candidate position with more stable path-gain even though average path gain may be lower but still sufficient. There may be some spread that may be considered to indicate too much instability and disqualify the candidate position irrespective of other metrics for example regarding average for that candidate position. This way, for example path gain variability can be used as a quality metric. Other quality metrics that may be formed taking into account reliability and based on several same type of measurements may be based on lowest number of dropped packets and/or lowest variation in power for the period the measurements are performed,

An additional way to include stability in quality metrics may be to perform said several same type of measurements from a candidate position with small movements around the candidate position between the measurements so that the measurements and/or how the quality metric is formed based on these, will take into account changes due to the small movements. If the changes are substantial this indicate that the candidate position may not be a good choice for stable relaying.

Action 506

The link quality metrics may be stored in association with candidate positions, respectively. Storage may be in connection with forming of the metrics, by and/or in the same node that formed them, and may be stored in or via several different nodes. Reason for storing them may both be for short terms and long term (re)use as already indicated above. If the real node 115 forms the link quality metrics it is reasonable that it also stores them locally, at least for short term use and evaluation based on them, but may alternatively or additionally send them to the network or node(s) thereof or connected to them, for example in order for these node(s) to further process the metrics and/or use them and/or for long term storage.

Action 507

It is formed single metrics for said candidate positions, respectively, based on at least link quality metrics, that is, based on one or more first relay-link quality metrics and one or more first access-link quality metrics. The single metric may thus take into account and be with regard to a total link quality and may correspond to a estimation of a total quality of involved links from respective candidate position. Forming the single metric may thus involve and/or is a result from estimating total link quality from the measurements. Estimating the of total path quality and/or forming said single metric may be made by for example taking the minimum of the estimated individual link data rates, as also exemplified elsewhere herein.

The total link and/or path quality estimated, for example when forming the single metric, may in addition to being based on measurements on the relay and access links, on for example reference signals, may also take into account other information that may be available and relevant, such as regarding power, bandwidth and interference.

The present action may for similar reasons as Action 505 be performed by the first relay node 115, but since the single metric for respective candidate position may be specific for embodiments herein and typically not conventional as the link quality metrics, it may in some situations be desirable to let another node than the first relay node 115 to form, e.g. compute, the single metric based on the link quality metrics. However, bandwidth and delays can be saved if the single quality metrics are formed by the relay node 115 and then sent to the network instead of sending the all link quality metrics to the network since the link quality metrics typically correspond to a much larger amount of information than the single metrics.

For example, in case of data rate as link quality metric, the measurements on each link may result in an average data rate for the access-link to a wireless device and another average data rate for the relay-link. Since the lower data rate may be considered to correspond to the maximum achievable data rate over both links, it may be used as the single metric in this case.

Note that when there are more than one wireless device and thus several accesslinks, and thus more than one communication link between respective one of these wireless devices and the relay node, a combinational, e.g. average, quality metric for the access-link may be first formed from the first quality metrics of respective communication link. For example in the data rate case, the average access link data rate for the wireless devices may be used as the quality metric for the access-link. Then, as already mentioned above, the data rate quality metric that is lowest of the access-link and the relay link may be chosen as the single metric. Another way to form a combinational metric is the so called “x-percentile”. For example, with x=5, that is, the 5th-percentile, the quality metric is about the worst 5% have, and hence if these can be made to experience “good enough” quality, the other 95% should thus experience better quality than that.

In some embodiments, the single metric is also based on one or more further metrics, such as from previous measurements and/or based on one or more quality of service levels associated with the first wireless device(s). Previous measurements and such service levels are further discussed below.

It is realized the single metric facilitates comparison between candidate positions and is a way where several different types of metrics can be combined and in the process for example be weighted according to how important they are considered in relation to each other.

Action 508

The candidate positions are evaluated based on the single metrics and one or more criteria in order to find a candidate position to use to accomplish improved communication. That is, to find a candidate position that works well and improves the situation compared to if no relay node is used and for example the radio network node 110 directly communicates with the wireless device(s) 120. The criteria may be predetermined and/or may be adjusted in response to change of how much improvement is required through use if the relay node 115. There may be several improvement levels associated with different predetermined criteria, respectively.

The evaluation may be performed be the first relay node 115 itself, and/or it may be convenient to let the same node(s) that performed Acton 507 also perform the present action, or there may be separate nodes involved. The evaluation is further discussed below.

The candidate position, if any, that accomplishes improved communication, may be one with its single metric corresponding to at least an acceptable total link quality, for example above a threshold and/or that is best among the candidate positions of the candidate path. If no candidate position that is sufficiently good is found, that is, no position providing a sufficient improvement, the candidate path may be extended and/or new candidate positions added, measured from, evaluated, etc, until there is a candidate position found that is sufficiently good according to the evaluation.

Action 509

The first relay node 115 is then positioned in such found candidate position and may from there, by relaying, participate in serving of the first wireless device(s) 120.

Although not indicated as a specific action in Figure 5, information identifying the candidate positions evaluated in Action 508 and considered good enough for use, or potential use, according to some criteria for this that may be predetermined, may be stored for later (re)use. For example stored together with associated data, such as the link metrics and/or the single metric. The storing may involve the same node(s) involved in storing of link quality metrics as in Action 506.

It should be realized that all or some of the actions described above may be repeated periodically and/or if/when the total link quality changes, such as gets too poor when the relay node is positioned in a candidate position although it previously was evaluated provide improvement and/or sufficient total link quality.

Moreover, when moving the first relay node 115 and/or when determining candidate path(s) to use, it may be taken into account transmit power needed and/or transport power for the relay mode, such as battery power available and/or needed. Transport power may be less need to consider if the relay node can use positions where it can land and/or charge If the first relay node 115 need to move away to charge and cannot longer perform relaying from a found suitable candidate position, it may in time signal this to for example the network or to a replacement relay node, and a replacement relay node may be moved to the position or to a proximity position and take over the relaying before it is negatively affected. Such replacement relay node may, in advance, be provided with all relevant information it needs so the replacement can be performed as smooth and seamless as possible, with no or minimal disturbance regarding the relaying.

Figure 6 is a flowchart for describing and discussing embodiments indicated above that involve previous measurements. Action 601

This action may correspond to Action 501 and is thus about that a decision is taken at some point in time to use a relay node, for example the relay node 115, to improve communication for one or more first wireless devices, such as the wireless device 120-1 and/or 120-2 referred to as the wireless device(s) 120 in the following for simplicity, located in a certain area, for example the serving area 125 and/or the first area 152a and/or the second area 152b.

Action 602

It is then checked if there exists previously measured candidate position(s) for said certain area.

Action 603

If previously measured candidate position(s) exists for said area, it is decided whether to use these or not.

Decision to use may follow if the previous candidate positions have some indication of that they likely will or may provide improvements also for the present situation, for example if they previously have been evaluated as “good” or at least “acceptable”, or even been successfully used by a relay node in the past.

Action 604

Both in case there are no previously measured candidate positions to use or if it is decided not to use such, the candidate path to be used in response to the decision of Action 601 will include only new candidate positions. Provision of the candidate path and new candidate positions thereof may be as described elsewhere herein for such situation.

Action 605

In case there exists, and is decided to use, previously measured candidate positions, the candidate path to be used in response to the decision of Action 601 will include one or more such previously measured candidate positions. As already described above, the candidate path may contain only such previously measured candidate position(s), or it may also contain new candidate positions. Provision of the candidate path including previously measured candidate positions may be as described elsewhere herein for such situation.

Previously measured candidate positions and some aspects of them and their use are also further commented below.

Figure 7 is a combined signalling diagram and flowchart for describing and discussing some examples and embodiments herein, and related actions, specifically regarding what above was referred to as previous measurements that may be performed with purpose to explore and find suitable and/or potential candidate positions for later use by an relay node, such as the relay node 115. This may be of particular interest for new areas without any previous known and/or potentially useful candidate positions but may alternatively or additionally be used to find new and potentially better candidate positions for an area that already has some associated candidate positions. Actions as exemplified in Figure 7 may thus be performed separate from any decision, and for example need, to actually use a relay node for relaying. Except for this, the method and actions relating to Figure 7 may in many aspects be similar or same as discussed in relation to Figure 5, similar and corresponding measurements and evaluation may be performed etc. The following will primarily focus on differences to avoid repeating information.

The actions may be part of a method regarding positioning of a relay node, such as the first relay node 115, even though a relay node as such need no be involved in the actions. Although some of the actions in the figure are indicated as being performed by the second relay node 215, it is not actually needed that a relay node performs these actions. Instead of the second relay node 215 performing the actions, they may be performed by a node with moving and measuring capabilities relevant for a relay node, such as the first relay node 115, but that need not to have any relay functionality itself or that have non-active relay functionality when the actions are performed. Such node without relay functionality may be referred to as a measurement node herein.

The purpose with the relaying as such is as above, such as to facilitate and/or improve communication for one or more wireless devices located in a certain area, for example the serving area 125 and/or the first area 152a and/or the second area 152b. The purpose with the method and actions of Figure 7 may instead be to find candidate positions for positioning of a relay node from where it later can relay communication and thereby participate in serving one or more wireless devices in said certain area. The wireless devices are in Figure 7 represented by wireless device 220-1 and/or 220-2, referred to as the wireless device(s) 220 in the following for simplicity, and are located in said certain area.

The actions in the figure and in the following are indicated as being performed by either or both of the second radio network node 210 and the second relay node 215, which may or may not be the same nodes as the first radio network node 110 and the first relay node 115, as already been discussed. Similarly as mentioned in connection with the method of Figure 5, some actions are better or may be preferred to be performed by either one of the second radio network node 210 and the second relay node 215, but a lot of combinations are possible. Same as for Figure 5, in some embodiments, although not indicated in the figure, other nodes may participate in performing the actions, such as other nodes of the wireless communication network 100, or that are connected to it, for example the further network 140 and/or the further node 141.

The actions may be taken in any suitable order and/or be carried out fully or partly overlapping in time when this is possible and suitable.

Action 700

This action may correspond to Action 500. However, in the present method it may be more likely that configuration of wireless devices are taken place since these may be controlled and for example employed for purpose of participating in the method, that is, for measuring purposes, and may thus be available for manipulation in a way that may not be the case for wireless devices that are associated with real users, as typically is the case with the method of Figure 5. It is of course also possible, as in Action 500, to utilize reference signals, such as SRS, if such are known and available without having to configure any wireless device(s).

Action 701

It is obtained a measurement path corresponding to a candidate path discussed above. The different naming is to accentuate that for embodiments of the present method the purpose is rather to find positions corresponding to candidate positions to measure from and evaluate, so good or potentially good ones are found and can be used later. For example be part of candidate paths as discussed above in relation to Figure 5.

Except for this, the measurement path may be obtained as has been described above regarding candidate paths, for example under Action 502, with only new candidate positions along it or containing also candidate positions based on previous measurements, and/or previous evaluations based on these measurements. Action 702

This action corresponds to Action 503 and the second relay node 215 is moved along or according to, the measurement path.

Acton 703

This action corresponds to Action 504. The second relay node 215 performs measurements on relay-link and access-link from measurement positions along the measurement path. The one or more candidate positions along the measurement path, that is, the positions to measure from, may be determined as discussed above.

Action 704

This action corresponds to Action 505. The second relay node 215 and/or node or nodes of the wireless communication network 100 or node(s) connected to it, form, based on said measurements, link quality metrics for candidate positions, respectively, for both relay-link and access-link.

Action 705

This action corresponds to Action 506. The link quality metrics may be stored in association with their candidate positions, respectively.

Action 706

Based on the formed link quality metrics, the measurement positions may be evaluated and some be determined as at least potentially good or acceptable candidate positions for later use by a relay node, for example as in the method of Figure 5. This may involve evaluation and/or forming a single metric as in Action 507 and/or 508, and the present action may at least partly correspond to these actions. However, when the purpose is just to find likely or potentially good or acceptable candidate positions for later use, there is no need to be satisfied after only a single good or acceptable candidate position has been found as may be the case when performing the method of Figure 5. It may also be of less benefit to form a single metric in the present method and/or evaluate the positions in the exact same way as in the method of Figure 5. However, it may be of interest to do this in any case just to get the same data from both methods and keep things as similar as possible. Action 707

At least the measurement positions that are evaluated and determined as at least potentially good or acceptable candidate positions, should be stored, preferably in association with said certain area. Also their link quality metrics may be stored, and a single quality metric if such has been formed. They may be stored just as any candidate positions that have been evaluated as sufficiently good, for example as in the method of Figure 5, or potentially good or acceptable candidate positions found trough the present method may be stored as special ones, especially if these have been determined and for example evaluated in a different way than candidate positions evaluated as part of the method of Figure 5. Except for this, storage may be performed similarly and with involvement of same or corresponding nodes as for the storage of candidate positions, and for example link metrics, as in the method of Figure 5.

Previous measurements regarding a certain area, such as above and/or for example quality metrics from previous executions of methods as discussed above, for example in relation to Figures 5-7, may of course also be stored.

Previous measurements may make it possible to find better and/or quicker candidate paths and positions to use with embodiments herein, e.g. in the method of Figure 5. The measurement results and/or resulting quality metrics from such previous measurement may also be considered when a single metric is formed per candidate positions when performing the method as described in relation to Figure 5.

For example, based on result from such previous measurements it may be known that certain candidate positions: provide more stable quality of service over longer periods of time that may be of interest to take into account, e.g. give such positions some increased weight or priority over other regarding reuse, and/or provide better or worse quality of service at certain times or time intervals during the day, which also may be of interest to take into account if such time interval is relevant when performing the method.

Note that as already mentioned, the second relay node 215 may be the same or a different node than the first relay node 115, for example a node able to perform measurements as in embodiments herein, and possibly also to evaluate these as described herein, but that may not have relay capability. When the involved relay node(s) and/or measurement node differ, they should have same or sufficiently close relevant properties so that the previous measurements, for example performed by the second relay node 215 or the measurement node, are relevant also for the first relay node 115. This also applies for the second radio network node 210, mutatis mutandis, that is preferred to be the same as the first radio network 110 node but may be a different one. If the second radio network node 210 is not the same as the first radio node 110, its location and relevant properties should be the same or sufficiently close to those of the first radio network node 110 to make previous measurements relevant. The skilled person is able to determine if previous measurements involving a second relay node 215 or measurement node without relay capabilities, and/or second radio network 210 that differ from the first relay node 115 and/or first radio network node 110, are relevant later or not, and this may be taken into account for example in a decision as in Action 603.

Regarding quality of service levels as mentioned herein and for example above in connection with Action 507. For example: In some embodiments, at least such where the first wireless device(s) 120 comprises or corresponds to a wireless device prioritized to experience a certain quality of service level according to some criteria that may be predetermined, for example set by the operator of the wireless communication network 100, and that may translate to that this wireless device at least always be able to access a data rate of X Mbps. A quality of service level may correspond to a user eligible to a certain quality of service that can be provided through a relay node, for example when a stationary radio network node, such as the first radio network node 110 cannot provide this. Respective wireless device may be associated with a number or similar indicating such quality of service level and which number may be used as a further metric that the single metric is based on. Assume, in a more specific example, that there is link quality metric such as above that is computed based on present measurements on two first wireless devices 120-1, 120-2 from a candidate position #1 , that corresponds to a total link quality metric that corresponds to that Y1 Mbps data rate is available for respective one of these wireless devices. If any one of the first wireless devices 120-1, 120-2 is entitled to a quality of service level that correspond to X Mbps that is higher than Y1 , then the candidate position may be disqualified to be used in this situation since it is not good enough or acceptable taking the service level into account. The single metric may therefore simply be set to something that will have such effect, for example if a total link quality metric for the candidate position is Y1, Y1 may simply set to 0 Mbps when taking into account also quality of service level. For other candidate positions #2-#3 assume the computed link quality metrics correspond to Y2 and Y3 Mbps and that the links regarding the first wireless device associated with the X1 quality of service level from respective one of these candidate positions have respective data rate link quality metric above X Mbps. The single metric for these candidate positions may then simply be Y2 and Y3. In the evaluation of the candidate positions #1-#3 is based on the single metric, the one or more criteria to find the single candidate position may in this example be to find the candidate position with highest single metric, in the example highest Mbps, but that at least must be above Z Mbps, that may correspond to a general minimum improvement level to be reached by respective first wireless device. It is here implied that Z<X. Hence, in the example, the evaluation would result in a candidate position of #2 or #3 to be used, for example the position first above Z since the single metric in this example will be set to 0 Mbps if the link quality metric for the first wireless device with the X service level would be below X Mbps.

In some embodiments, the single metric mentioned herein is a cost or score value formed according to a predetermined cost or score function. The evaluation can then comprise to find out which cost(s) or score(s) that are below or above a certain cost threshold or score threshold, meaning that they are or should be able to accomplish said improved communication. The candidate position associated with a cost or score passing such threshold may be then be selected as said single candidate position, e.g. the candidate position with cost or score first passing such threshold, and/or the candidate position with the lowest cost or highest score may be found in the evaluation and correspond to said found candidate position. Said one or more criteria may thus in this case comprise or correspond to a cost or score threshold. Cost or score function may be beneficial to use when there are several different type of metrics involved, e.g. one or more type of first quality metrics and/or one or more type of further metrics since then the evaluation become straightforward and relatively simple, and it is also possible to adjust, such as add and/or remove, metrics used and adjust the function, without changing the one or more criteria for finding singe candidate position since the one or more criteria simply may be the candidate position with the lowest cost or highest score below or above a cost or score threshold.

Figure 8 is a flowchart schematically illustrating embodiments of a method, performed by one or more devices or nodes, according to embodiments herein and based on the above discussed examples and embodiments. The method is for or regarding positioning of a first relay node, exemplified in the following by the first relay node 115, for relaying communication, such as in order to improve communication, between a first radio network node, exemplified in the following by the first radio network node 110, and one or more first wireless device(s), such as the first wireless device 120-1 and/or 120-2, referred to as first wireless device(s) 120 in the following for simplicity, located in a certain area. Said certain area may for example be the serving area 125 and/or the first area 152a and/or the second area 152b..

The method and/or actions thereof may be performed by a single device or node or be performed distributed by more than one device or node. For example, the method and/or actions thereof may be performed by either or both of the first radio network node 110 and the first relay node 115, and/or by other nodes, such as other nodes of the wireless communication network 100, or that are connected to it, such as the further network 140 and/or the further node 141, where the latter may be the case if the method, or part of it, is provided as a cloud service or similar.

Actions below that are about to “initiate” another action are to cover if there is a node or nodes that controls and for example trigger another node(s) to perform the action(s) that is being initiated. The decision to perform is in this case in the initiating node(s) and it is justified that the claims are covering such node and not only the node(s) that are actually performing the actions that are being initiated. Note that in case a node or nodes perform an action itself, such node(s) also initiate the action when it starts to perform the action, either in response to an internal decision or trigger to do so, or in response to that the node(s) has been triggered to do so externally, for example by another node(s) that “only” initiated the action.

The actions below that may form the method may be taken in any suitable order and/or be carried out fully or partly overlapping in time when this is possible and suitable.

Action 801

Said device(s) or node(s) initiate to move a first measurement node along a path, for example a measurement path or candidate path as mentioned elsewhere herein, for example anyone of the candidate paths 216, 316, 416. The path comprises one or more candidate positions, such as candidate positions labelled with 118, 318 and 418 in the above examples, for positioning of the first relay node 115.

Said first measurement node may be the first relay node 115 or the second relay node 215. In some embodiments the first measurement node is a node with relevant measurement capabilities as has been discussed herein and that can be moved and be positioned as the first relay node 115, but that itself may lack relaying capabilities. This action may fully or partly correspond to Action 503 or 702.

Action 802

Said device(s) or node(s) initiate to evaluate at least one of said one or more candidate positions according to one or more criteria to find a candidate position, or one or more candidate positions, for positioning of the first relay node 115 to perform said relaying. The evaluation of a respective candidate position of said at least one of said one or more candidate positions is based on measurements performed by the first measurement node on both a first relay-link, in the following exemplified by the first relay link 122, and a first access-link, in the following exemplified by the first access link 124, when the first measurement node is positioned in the respective candidate position. Said first relay-link 122 corresponds to a communication link between said first measurement node and the first radio network node 110. Said first access-link 124 corresponds to at least one communication link between said first measurement node and said one or more first wireless devices 120 in said certain area.

Said evaluation of the respective candidate may be based on one or more first relay-link quality metrics and on one or more first access-link quality metrics associated with the respective candidate position. These metrics being formed from said measurements performed by the first measurement node on the first relay-link 122 and on the first access-link 124 from the respective candidate position.

Said one or more first relay-link quality metrics and said one or more first accesslink quality metrics may be of one or more of the following types: data rate, latency, path gain, Signal to Noise Ratio (SNR), Signal to Interference and Noise Ratio (SINR), received power, BLock Error Rate (BLER), Reference Signal Received Power (RSRP), Reference Signal Received Quality (RSRQ).

In some embodiments, said one or more first relay-link quality metrics and/or said one or more first access-link quality metrics are based on several same type of measurements by the first measurement node on the same link when positioned in the respective candidate position. Said one or more first relay-link quality metrics and/or said one or more first access-link quality metrics may thereby comprise metrics indicating stability over a period of time during which said several measurements for respective candidate position were performed.

Further, the evaluation of the respective candidate position of said at least one candidate positions 218; 318; 418 may be based on a respective single metric formed for the respective candidate position and that is based on both said one or more first relaylink quality metrics and said one or more first access-link quality metrics.

Said respective single metric, in addition to said quality metrics regarding the relaylink and the access-link, may be based on one or more further metrics associated with the respective candidate position. Said one or more further metrics may be metrics based on one or more of the following: previous measurements performed by a second measurement node, for example the second relay mode 215 or another measurement node that itself is not used for relaying, from the respective candidate position on a second relay-link, for example the second relay-link 222, between the second measurement node and a second radio network node, for example the second radio network node 211 , corresponding to the first radio network node 111, and on a second access-link, for example the second relay-link 224, between said second measurement node and one or more second wireless device, for example one or more of the second wireless devices 220-1 , 220-2, located in said certain area: and one or more quality of service levels based on wireless device identity and associated with at least one of said one or more first wireless devices 120.

In some embodiments, the single metric is a cost or score value formed according to a predetermined cost or score function.

This action may fully or partly correspond to Action 508 or 706.

Action 803

Said device(s) or node(s) may initiate to position, if said evaluation resulted in a found candidate position, said first relay node 115 in such found candidate position to from there perform said relaying, or in other words relay said communication.

This action may fully or partly correspond to Action 509.

Figure 9 is a schematic block diagram for illustrating embodiments of how one or more devices or nodes, for example device(s) 900, may be configured to perform the method and actions discussed in connection with Figure 8. The device(s) 900 may correspond to the node(s) discussed above for performing the method and/or actions.

Said device(s) 900 may thus be for supporting performance of the method, such as for supporting evaluation of candidate positions for positioning of the first relay node 115 to improve communication for said one or more first wireless devices 120 located in said certain area by relayed communication, via the first relay node 115, between the first radio network node 110 of the wireless communication network 100 and said one or more first wireless devices 120.

The device(s) 900 may comprise processing module(s) 901, such as a means, one or more hardware modules, including e.g. one or more processors, and/or one or more software modules for performing said method and/or actions.

The device(ls) 900 may further comprise memory 902 that may comprise, such as contain or store, computer program(s) 903. The computer program(s) 903 comprises 'instructions' or 'code' directly or indirectly executable by the device(s) 900 to perform said method and/or actions. The memory 902 may comprise one or more memory units and may further be arranged to store data, such as configurations and/or applications involved in or for performing functions and actions of embodiments herein.

Moreover, the device(s) 900 may comprise processor(s) 904, i.e. one or more processors, as exemplifying hardware module(s) and may comprise or correspond to one or more processing circuits. In some embodiments, the processing module(s) 901 may comprise, e.g. ‘be embodied in the form of’ or ‘realized by’ processor(s) 904. In these embodiments, the memory 902 may comprise the computer program 903 executable by the processor(s) 904, whereby the device(s) 900 is operative, or configured, to perform said method and/or actions.

Typically the device(s) 900, e.g. the processing module(s) 901, comprises Input/Output (I/O) module(s) 905, configured to be involved in, e.g. by performing, any communication to and/or from other network nodes and/or units and/or devices, such as sending and/or receiving information to and/or from other nodes. The I/O module(s) 905 may be exemplified by obtaining, e.g. receiving, module(s) and/or providing, e.g. sending, module(s), when applicable.

Further, in some embodiments, the device(s), e.g. the processing module(s) 901, comprises one or more of initiating module(s), movement module(s), evaluating module(s=, positioning module(s), as exemplifying hardware and/or software module(s) for carrying out actions of embodiments herein. These modules may be fully or partly implemented by the processor(s) 904.

Hence:

The device(s) 900, and/or the processing module(s) 901, and/or the processor(s) 904, and/or the I/O module(s) 905, and/or the initiating module(s) are operative, or configured, to initiate to move the first measurement node along the path comprising said one or more candidate positions for positioning of the relay node 115. The device(s) 900, and/or the processing module(s) 901 , and/or the processor(s) 904, and/or the I/O module(s) 905, and/or the initiating module(s) are operative, or configured, to initiate to evaluate at least one of said one or more candidate positions according to said one or more criteria to find said candidate position for positioning of the first relay node 115 to perform said relaying.

Further, the device(s) 900, and/or the processing module(s) 901 , and/or the processor(s) 904, and/or the I/O module(s) 905, and/or the initiating module(s) may be operative, or configured, to initiate to position, if said evaluation resulted in a found candidate position, said first relay node in said found candidate position to from there perform said relaying.

Figure 10 is a schematic drawing illustrating some embodiments relating to computer program(s) and carrier(s) thereof to cause said device(s) 900 discussed above to perform the associated method and actions. The computer program(s) may be the computer program 903 and comprises instructions that when executed by the processing circuit(s) 904 and/or the processing module(s) 901, causes the device(s) to perform as described above. In some embodiments there is provided a carrier, or more specifically a data carrier, e.g. a computer program product, comprising the computer program. The carrier may be one of an electronic signal, an optical signal, a radio signal, and a computer readable storage medium, e.g. a computer readable storage medium 1001 as schematically illustrated in the figure. One or more of the computer program(s) 903 may thus be stored on the computer readable storage medium 1001. By carrier may be excluded a transitory, propagating signal and the data carrier may correspondingly be named non-transitory data carrier. Non-limiting examples of the data carrier being a computer readable storage medium is a memory card or a memory stick, a disc storage medium, or a mass storage device that typically is based on hard drive(s) or Solid State Drive(s) (SSD). The computer readable storage medium 1001 may be used for storing data accessible over a computer network 1002, e.g. the Internet or a Local Area Network (LAN). One or more of the computer program(s) 903 may furthermore be provided as pure computer program(s) or comprised in a file or files. The file or files may be stored on the computer readable storage medium 1001 and e.g. available through download e.g. over the computer network 1002 as indicated in the figure, e.g. via a server. The server may e.g. be a web or File Transfer Protocol (FTP) server. The file or files may e.g. be executable files for direct or indirect download to and execution on said device(s) to cause performance as described above, e.g. by execution by the processing circuit(s) 904. The file or files may also or alternatively be for intermediate download and compilation involving the same or another processor to make them executable before further download and execution causing said device(s) 900 to perform as described above.

Note that any processing module(s) and circuit(s) mentioned in the foregoing may be implemented as a software and/or hardware module, e.g. in existing hardware and/or as an Application Specific Integrated Circuit (ASIC), a field-programmable gate array (FPGA) or the like. Also note that any hardware module(s) and/or circuit(s) mentioned in the foregoing may e.g. be included in a single ASIC or FPGA, or be distributed among several separate hardware components, whether individually packaged or assembled into a System-on-a-Chip (SoC).

Those skilled in the art will also appreciate that the modules and circuitry discussed herein may refer to a combination of hardware modules, software modules, analogue and digital circuits, and/or one or more processors configured with software and/or firmware, e.g. stored in memory, that, when executed by the one or more processors may make any node(s), device(s), apparatus(es), network(s), system(s), etc. to be configured to and/or to perform the above-described methods and actions.

Identification by any identifier herein may be implicit or explicit. The identification may be unique in a certain context, e.g. in the wireless communication network or at least in a relevant part or area thereof.

The term "network node" or simply “node” as used herein may as such refer to any type of node that may communicate with another node in and be comprised in a communication network, e.g. Internet Protocol (IP) network or wireless communication network. Further, such node may be or be comprised in a radio network node (described below) or any network node, which e.g. may communicate with a radio network node. Examples of such network nodes include any radio network node, a core network node, Operations & Maintenance (O&M), Operations Support Systems (OSS), Self-Organizing Network (SON) node, etc.

The term "radio network node" as may be used herein may as such refer to any type of network node for serving a wireless communication device, e.g. a so called User Equipment or UE, and/or that are connected to other network node(s) or network element(s) or any radio node from which a wireless communication device receives signals from. Examples of radio network nodes are Node B, Base Station (BS), MultiStandard Radio (MSR) node such as MSR BS, eNB, eNodeB, gNB, network controller, RNC, Base Station Controller (BSC), relay, donor node controlling relay, Base Transceiver Station (BTS), Access Point (AP), New Radio (NR) node, transmission point, transmission node, node in distributed antenna system (DAS) etc.

Each of the terms "wireless communication device", “wireless device”, "user equipment" and "UE", as may be used herein, may as such refer to any type of wireless device arranged to communicate with a radio network node in a wireless, cellular and/or mobile communication system. Examples include: target devices, device to device UE, device for Machine Type of Communication (MTC), machine type UE or UE capable of machine to machine (M2M) communication, Personal Digital Assistant (PDA), tablet, mobile, terminals, smart phone, Laptop Embedded Equipment (LEE), Laptop Mounted Equipment (LME), Universal Serial Bus (USB) dongles etc.

While some terms are used frequently herein for convenience, or in the context of examples involving other a certain, e.g. 3GPP or other standard related, nomenclature, it must be appreciated that such term as such is non-limiting

Also note that although terminology used herein may be particularly associated with and/or exemplified by certain communication systems or networks, this should as such not be seen as limiting the scope of the embodiments herein to only such certain systems or networks etc.

As used herein, the term "memory" may refer to a data memory for storing digital information, typically a hard disk, a magnetic storage, medium, a portable computer diskette or disc, flash memory, random access memory (RAM) or the like. Furthermore, the memory may be an internal register memory of a processor.

Also note that any enumerating terminology such as first device or node, second device or node, first base station, second base station, etc., should as such be considered non-limiting and the terminology as such does not imply a certain hierarchical relation. Without any explicit information in the contrary, naming by enumeration should be considered merely a way of accomplishing different names.

As used herein, the expression "configured to" may e.g. mean that a processing circuit is configured to, or adapted to, by means of software or hardware configuration, perform one or more of the actions described herein.

As used herein, the terms "number" or "value" may refer to any kind of digit, such as binary, real, imaginary or rational number or the like. Moreover, "number" or "value" may be one or more characters, such as a letter or a string of letters. Also, "number" or "value" may be represented by a bit string. As used herein, the expression “may” and "in some embodiments" has typically been used to indicate that the features described may be combined with any other embodiment disclosed herein.

In the drawings, features that may be present in only some embodiments are typically drawn using dotted or dashed lines.

As used herein, the expression "transmit" and "send" are typically interchangeable. These expressions may include transmission by broadcasting, uni-casting, group-casting and the like. In this context, a transmission by broadcasting may be received and decoded by any authorized device within range. In case of unicasting, one specifically addressed device may receive and encode the transmission. In case of group-casting, e.g. multicasting, a group of specifically addressed devices may receive and decode the transmission.

When using the word "comprise" or "comprising" it shall be interpreted as nonlimiting, i.e. meaning "consist at least of'. The embodiments herein are not limited to the above described preferred embodiments. Various alternatives, modifications and equivalents may be used. Therefore, the above embodiments should not be taken as limiting the scope of the present disclosure, which is defined by the appending claims.

Claims

1 . A method, performed by one or more devices (100; 110; 115; 140; 141), regarding positioning of a first relay node (115) for relaying communication between a first radio network node (110) of a wireless communication network (100) and one or more first wireless devices (120) located in a certain area (125; 152a; 152b), wherein the method comprises:

- initiating to move (503; 801) a first measurement node (115; 215) along a path (216; 316; 416) comprising one or more candidate positions (218;318; 418) for positioning of the first relay node (115), and

- initiating to evaluate (508; 802) at least one of said one or more candidate positions (218; 318; 418) according to one or more criteria to find a candidate position (218-5; 318-10; 418-6) for positioning of the first relay node (115) to perform said relaying, wherein the evaluation of respective candidate position of said at least one of said one or more positions (218; 318; 418) is based on measurements performed by the first measurement node (115; 215) on both a first relay-link (122) and a first access-link (124) when positioned in the respective candidate position, wherein said first relay-link (122) corresponds to a communication link between said first measurement node (115;215) and the first radio network node (110), and wherein said first access-link (124) corresponds to at least one communication link between said first measurement node (115; 215) and said one or more first wireless devices (120) in said certain area (125; 152a; 152b).

2. The method as claimed in claim 1 , wherein the method further comprises:

- initiating to position (509; 803), if said evaluation resulted in a found candidate position, said first relay node (115) in said found candidate position (218-5; 318-10; 418-6) to from there perform said relaying.

3. The method as claimed in any one of claims 1-2, wherein said evaluation of the respective candidate position is based on one or more first relay-link quality metrics and on one or more first access-link quality metrics associated with the respective candidate position and that are formed from said measurements performed by the first measurement node (115; 215) on the first relay-link (122) and on the first access-link (124) from the respective candidate position.

4. The method as claimed in claim 3, wherein said one or more first relay-link quality metrics and said one or more first access-link quality metrics are of one or more of the following types: data rate, latency, path gain, Signal to Noise Ratio, Signal to Interference and Noise Ratio, received power, Block Error Rate, Reference Signal Received Power, Reference Signal Received Quality.

5. The method as claimed in claim 4, wherein said one or more first relay-link quality metrics and/or said one or more first access-link quality metrics are based on several same type of measurements by the first measurement node (115; 215) on the same link when positioned in the respective candidate position, whereby said one or more first relay-link quality metrics and/or said one or more first access-link quality metrics comprise metrics indicating stability over a period of time during which said several measurements for respective candidate position were performed.

6. The method as claimed in any one of claims 3-5, wherein the evaluation of the respective candidate position is based on a respective single metric formed for the respective candidate position and that is based on both said one or more first relaylink quality metrics and said one or more first access-link quality metrics.

7. The method as claimed in claim 6, wherein said respective single metric, in addition to said quality metrics regarding the relay-link and the access-link, is based on one or more further metrics associated with the respective candidate position.

8. The method as claimed in claim 7, wherein said one or more further metrics are metrics based on one or more of the following: previous measurements performed by a second measurement node (215) from the respective candidate position on a second relay-link (222) between the second measurement node (215) and a second radio network node (211) corresponding to the first radio network node (111) and on a second access-link (224) between said second measurement node (215) and one or more second wireless device (220) located in said certain area (125; 152a; 152b); one or more quality of service levels based on wireless device identity and associated with at least one of said one or more first wireless devices (120).

9. The method as claimed in any one of claims 6-8, wherein the single metric is a cost or score value formed according to a predetermined cost or score function.

10. Computer program (703) comprising instructions that when executed by one or more processors (704) causes one or more devices (100; 110; 115; 140; 141) to perform the method according to any one of claims 1-9.

11. Carrier comprising the computer program (703) according to claim 10, wherein the carrier is one of an electronic signal, optical signal, radio signal or computer readable storage medium (1001).

12. One or more devices (100; 110; 115; 140; 141) for supporting positioning of a first relay node (115) for relaying communication between a first radio network node (110) of a wireless communication network (100) and one or more first wireless devices (120a-b) located in a certain area (125; 152a; 152b), wherein said one or more devices are configured to: initiate to move (503; 801) a first measurement node (115; 215) along a path (216; 316; 416) comprising one or more candidate positions (218;318; 418) for positioning of the first relay node (115), and initiate to evaluate (508; 802) at least one of said one or more candidate positions (218; 318; 418) according to one or more criteria to find a candidate position (218-5; 318-10; 418-6) for positioning of the first relay node (115) to perform said relaying, wherein the evaluation of a respective candidate position of said at least one of said one or more candidate positions (218; 318; 418) is based on measurements performed by the first measurement node (115; 215) on both a first relay-link (122) and a first access-link (124) when positioned in the respective candidate position, wherein said first relay-link (122) corresponds to a communication link between said first measurement node (115; 215) and the first radio network node (110), and wherein said first access-link (124) corresponds to at least one communication link between said first measurement node (115; 215) and said one or more first wireless devices (120) in said certain area (125; 152a; 152b).

13. The one or more devices as claimed in claim 12, wherein said one or more devices are further configured to: initiate to position (509; 803), if said evaluation resulted in a found candidate position, said first relay node (115) in said found candidate position (218-5; 318-10; 418-6) to from there perform said relaying.

14. The one or more devices as claimed in any one of claim 12-13, wherein said evaluation of the respective candidate position is based on one or more first relaylink quality metrics and on one or more first access-link quality metrics associated with the respective candidate position and that are formed from said measurements performed by the first measurement node (115; 215) on the first relay-link (122) and on the first access-link (124) from the respective candidate position.

15. The one or more devices as claimed in claim 14, wherein said one or more first relay-link quality metrics and said one or more first access-link quality metrics are of one or more of the following types: data rate, latency, path gain, Signal to Noise Ratio, Signal to Interference and Noise Ratio, received power, Block Error Rate, Reference Signal Received Power, Reference Signal Received Quality.

16. The one or more devices as claimed in claim 15, wherein said one or more first relay-link quality metrics and/or said one or more first access-link quality metrics are based on several same type of measurements by the first measurement node (115; 215) on the same link when positioned in the respective candidate position, whereby said one or more first relay-link quality metrics and/or said one or more first access-link quality metrics comprise metrics indicating stability over a period of time during which said several measurements for respective candidate position were performed.

17. The one or more devices as claimed in any one of claims 14-16, wherein the evaluation of the respective candidate position is based on a respective single metric formed for the respective candidate position and that is based on both said one or more first relay-link quality metrics and said one or more first access-link quality metrics.

18. The one or more devices as claimed in claim 16, wherein said respective single metric, in addition to said quality metrics regarding the relay-link and the access- link, is based on one or more further metrics associated with the respective candidate position.

19. The one or more devices as claimed in claim 18, wherein said one or more further metrics are metrics based on one or more of the following: previous measurements performed by a second measurement node (215) from the respective candidate position on a second relay-link (222) between the second measurement node (215) and a second radio network node (211) corresponding to the first radio network node (111) and on a second access-link (224) between said second measurement node (215) and one or more second wireless device (220) located in said certain area (125; 152a; 152b); one or more quality of service levels based on wireless device identity and associated with at least one of said one or more first wireless devices (120).

20. The one or more devices as claimed in any one of claims 17-19, wherein the single metric is a cost or score value formed according to a predetermined cost or score function.