Method, apparatus and computer program

Abstract

There is provided a mobile phone user equipment comprising: means for detecting, for each of a plurality of cells, a number of transmission and reception points (TRPs) that are associated with each ce

Description

TECHNICAL FIELD

[0001] Various examples of this disclosure relate to methods, apparatuses, and computer programs for a communication network. BACKGROUND

[0002] A communication network can be seen as a facility that enables communications between two or more communication devices, or provides communication devices access to a data network. A mobile or wireless communication network is one example of a communication network. A communication device may be provided with a service by an application server.

[0003] Such communication networks operate in accordance with standards such as those provided by 3GPP (Third Generation Partnership Project) or ETSI (European Telecommunications Standards Institute). Examples of standards are the so-called 5G (5th Generation) standards provided by 3GPP. SUMMARY

[0004] Some examples of this disclosure will be described with respect to certain aspects. These aspects are not intended to indicate key or essential features of the embodiments of this disclosure, nor are they intended to be used to limit the scope thereof. Other features, aspects, and elements will be readily apparent to a person skilled in the art in view of this disclosure. For example, it should be appreciated that further aspects may be provided by the combination of any two or more of the various aspects described below.

[0005] According to a first aspect, there is provided a user equipment comprising: means for obtaining, for each of a plurality of cells, information that indicates a number of transmission and reception points, TRPs, that are associated with each cell, wherein each of the plurality of cells are candidates for serving the user equipment; means for selecting a cell from the plurality of cells based on the number of TRPs that are associated with each of the plurality of cells; and means for initiating a connection establishment with the cell that has been selected.

[0006] According to a second aspect, there is provided a method performed by a user equipment, the method comprising: obtaining, for each of a plurality of cells, information that indicates a number of transmission and reception points, TRPs, that are associated with each cell, wherein each of the plurality of cells are candidates for serving the user equipment; selecting a cell from the plurality of cells based on the number of TRPs that are associated with each of the plurality of cells; and initiating a connection establishment with the cell that has been selected.

[0007] According to a third aspect, there is provided a user equipment comprising: at least one processor, and at least one memory storing instructions that, when executed by the at least one processor, cause the user equipment to perform: obtaining, for each of a plurality of cells, information that indicates a number of transmission and reception points, TRPs, that are associated with each cell, wherein each of the plurality of cells are candidates for serving the user equipment; selecting a cell from the plurality of cells based on the number of TRPs that are associated with each of the plurality of cells; and initiating a connection establishment with the cell that has been selected.

[0008] According to a fourth aspect, there is provided a computer program comprising instructions, which when executed by a user equipment, cause the user equipment to perform at least the following: obtaining, for each of a plurality of cells, information that indicates a number of transmission and reception points, TRPs, that are associated with each cell, wherein each of the plurality of cells are candidates for serving the user equipment; selecting a cell from the plurality of cells based on the number of TRPs that are associated with each of the plurality of cells; and initiating a connection establishment with the cell that has been selected.

[0009] According to a fifth aspect, there is provided a user equipment comprising: circuitry configured to perform: obtaining, for each of a plurality of cells, information that indicates a number of transmission and reception points, TRPs, that are associated with each cell, wherein each of the plurality of cells are candidates for serving the user equipment; circuitry configured to perform: selecting a cell from the plurality of cells based on the number of TRPs that are associated with each of the plurality of cells; and circuitry configured to perform: initiating a connection establishment with the cell that has been selected.

[0010] The following are applicable to each (e.g., one or more, including all) of the above first to fifth aspects.

[0011] In some examples, a TRP that is associated with a cell is a TRP that has been detected by the user equipment, for the cell.

[0012] In some examples, the user equipment further is caused to perform: obtaining information about the plurality of cells, wherein each of the plurality of cells are candidates for serving the user equipment.

[0013] In some examples, the obtaining of the information comprises: determining, for each of the plurality of cells, the number of TRPs that are detected for each cell based on measurements performed by the user equipment

[0014] In some examples, a TRP is determined to be detected for a respective cell when a measured signal associated with the TRP is above a threshold level.

[0015] In some examples, the obtaining of the information comprises: receiving, from a network entity, the information that indicates the number of TRPs that are associated with each cell.

[0016] In some examples, the user equipment is further caused to perform: determining a value for ranking associated with each cell of the plurality of cells based on measurements performed by the user equipment; determining which cell of the plurality of cells has the highest value for ranking; determining which cells of the plurality of cells are within a threshold value of the value for ranking associated with the cell determined to have the highest value for ranking, wherein the cell that is selected for connection establishment is selected from the cells that are within the threshold value.

[0017] In some examples, the selecting of the cell comprises: selecting the cell, from the cells that are within the threshold value, with the highest number of TRPs.

[0018] In some examples, the selecting of the cell comprises: when there are two cells with the same highest number of TRPs, selecting the cell with the higher value for ranking.

[0019] In some examples, the selecting of the cell comprises: when there are two cells with the same highest number of TRPs, obtaining a number of beams associated with each of the two cells; and selecting the cell from the two cells based on the number of beams.

[0020] In some examples, the selected cell from the two cells is associated with a number of beams that are above a threshold amount of beams.

[0021] In some examples, the number of beams are determined perTRP associated with each cell, or are determined as a total number of beams across all TRPs that are associated with each cell.

[0022] In some examples, the user equipment is caused to perform: determining a number of beams associated with each of the cells that are within the threshold value of the cell determined to have the highest value for ranking, wherein the selecting of the cell is based on: the number of TRPs that are associated with respective cell, and the number of beams associated with the respective cell.

[0023] In some examples, the threshold value is configured using one of: system information, or radio resource control signalling.

[0024] In some examples, the selecting of the cell from the plurality of cells based on the number of TRPs that are associated with each of the plurality of cells comprises: determining, for each of the cells, whether the number of TRPs that are associated with the respective cell is above a threshold number, wherein the cell that is selected is a cell that is associated with a number of TRPs that is above the threshold number.

[0025] According to a sixth aspect, there is provided a user equipment comprising: means for obtaining, for each of a plurality of cells, information that indicates a number of transmission and reception points, TRPs, that are associated with each cell, wherein each of the plurality of cells are candidates for serving the user equipment; means for selecting a cell from the plurality of cells based on a value for ranking that is associated with each of the plurality cells, wherein, for each cell, the value for ranking is determined based on the number of TRPs that are associated with the respective cell; and means for initiating a connection establishment with the cell that has been selected.

[0026] According to a seventh aspect, there is provided a method performed by a user equipment, the method comprising: obtaining, for each of a plurality of cells, information that indicates a number of transmission and reception points, TRPs, that are associated with each cell, wherein each of the plurality of cells are candidates for serving the user equipment; selecting a cell from the plurality of cells based on a value for ranking that is associated with each of the plurality cells, wherein, for each cell, the value for ranking is determined based on the number of TRPs that are associated with the respective cell; and initiating a connection establishment with the cell that has been selected.

[0027] According to an eighth aspect, there is provided a computer program comprising instructions, which when executed by a user equipment, cause the user equipment to perform at least the following: obtaining, for each of a plurality of cells, information that indicates a number of transmission and reception points, TRPs, that are associated with each cell, wherein each of the plurality of cells are candidates for serving the user equipment; selecting a cell from the plurality of cells based on a value for ranking that is associated with each of the plurality cells, wherein, for each cell, the value for ranking is determined based on the number of TRPs that are associated with the respective cell; and initiating a connection establishment with the cell that has been selected.

[0028] According to a ninth aspect, there is provided a user equipment comprising: at least one processor, and at least one memory storing instructions that, when executed by the at least one processor, cause the user equipment to perform: obtaining, for each of a plurality of cells, information that indicates a number of transmission and reception points, TRPs, that are associated with each cell, wherein each of the plurality of cells are candidates for serving the user equipment; selecting a cell from the plurality of cells based on a value for ranking that is associated with each of the plurality cells, wherein, for each cell, the value for ranking is determined based on the number of TRPs that are associated with the respective cell; and initiating a connection establishment with the cell that has been selected.

[0029] According to a tenth aspect, there is provided a user equipment comprising: circuitry configured to perform: obtaining, for each of a plurality of cells, information that indicates a number of transmission and reception points, TRPs, that are associated with each cell, wherein each of the plurality of cells are candidates for serving the user equipment; circuitry configured to perform: selecting a cell from the plurality of cells based on a value for ranking that is associated with each of the plurality cells, wherein, for each cell, the value for ranking is determined based on the number of TRPs that are associated with the respective cell; and circuitry configured to perform: initiating a connection establishment with the cell that has been selected.

[0030] The following are applicable to each (e.g., one or more, including all) of the above sixth to tenth aspects.

[0031] In some examples, a TRP that is associated with a cell is a TRP that has been detected by the user equipment, for the cell.

[0032] In some examples, the user equipment is further caused to perform: obtaining information about the plurality of cells, wherein each of the plurality of cells are candidates for serving the user equipment.

[0033] In some examples, the obtaining of the information comprises: determining, for each of the plurality of cells, the number of TRPs that are detected for each cell based on measurements performed by the user equipment.

[0034] In some examples, a TRP is determined to be detected for a respective cell when a measured signal associated with the TRP is above a threshold level.

[0035] In some examples, the obtaining of the information comprises: receiving, from a network entity, the information that indicates the number of TRPs that are associated with each cell.

[0036] In some examples, the apparatus is further caused to perform: determining an initial value for ranking for each of the plurality of cells based on measurements associated with the respective cell; and scaling the initial value for ranking for each of the plurality of cells based on the number of TRPs that are associated with the respective cell, to determine the value for ranking for each of the plurality of cells.

[0037] In some examples, the initial value for ranking for each of the plurality of cells is increased based on the number of TRPs that are associated with the respective cell.

[0038] In some examples, the initial value for ranking is increased per TRP that is associated with the respective cell, such that the initial value for ranking is increased by a set value per TRP.

[0039] In some examples, for a cell that is associated with a number, N, of TRPs, the initial value for ranking is increased by: a set value multiplied by N-1.

[0040] In some examples, the value for ranking for each of the plurality of cells is increased by a set value when the respective cell is associated with at least two TRPs.

[0041] In some examples, the apparatus is further caused to perform: determining a number of TRPs associated with a cell that is currently serving the user equipment based on measurements performed by the user equipment; comparing the number of TRPs associated with the cell that is currently serving the user equipment with the number of TRPs associated with each of the plurality of cells, wherein, for each cell, the value for ranking is determined based on a difference between the number of TRPs that are associated with the respective cell and the number of TRPs associated with the cell that is currently serving the user equipment.

[0042] According to a eleventh aspect, there is provided a user equipment comprising: means for detecting, for each of a plurality of cells, a number of transmission and reception points, TRPs, that are associated with each cell, wherein each of the plurality of cells are candidates for serving the user equipment, wherein the number of TRPs that have been detected for each cell is based on measurements performed by the user equipment, wherein the measurements are used to identify characteristics associated with specific TRPs; means for selecting a cell from the plurality of cells based on the number of TRPs that are associated with each of the plurality of cells; and means for initiating a connection establishment with the cell that has been selected.

[0043] According to an twelfth aspect, there is provided a method performed by a user equipment, the method comprising: detecting, for each of a plurality of cells, a number of transmission and reception points, TRPs, that are associated with each cell, wherein each of the plurality of cells are candidates for serving the user equipment, wherein the number of TRPs that have been detected for each cell is based on measurements performed by the user equipment, wherein the measurements are used to identify characteristics associated with specific TRPs; selecting a cell from the plurality of cells based on the number of TRPs that are associated with each of the plurality of cells; and initiating a connection establishment with the cell that has been selected.

[0044] According to a thirteenth aspect, there is provided a computer program comprising instructions, which when executed by a user equipment, cause the user equipment to perform at least the following: detecting, for each of a plurality of cells, a number of transmission and reception points, TRPs, that are associated with each cell, wherein each of the plurality of cells are candidates for serving the user equipment, wherein the number of TRPs that have been detected for each cell is based on measurements performed by the user equipment, wherein the measurements are used to identify characteristics associated with specific TRPs; selecting a cell from the plurality of cells based on the number of TRPs that are associated with each of the plurality of cells; and initiating a connection establishment with the cell that has been selected.

[0045] According to a fourteenth aspect, there is provided a user equipment comprising: at least one processor, and at least one memory storing instructions that, when executed by the at least one processor, cause the user equipment to perform: detecting, for each of a plurality of cells, a number of transmission and reception points, TRPs, that are associated with each cell, wherein each of the plurality of cells are candidates for serving the user equipment, wherein the number of TRPs that have been detected for each cell is based on measurements performed by the user equipment, wherein the measurements are used to identify characteristics associated with specific TRPs; selecting a cell from the plurality of cells based on the number of TRPs that are associated with each of the plurality of cells; and initiating a connection establishment with the cell that has been selected.

[0046] According to a fifteenth aspect, there is provided a user equipment comprising: circuitry configured to perform: detecting, for each of a plurality of cells, a number of transmission and reception points, TRPs, that are associated with each cell, wherein each of the plurality of cells are candidates for serving the user equipment, wherein the number of TRPs that have been detected for each cell is based on measurements performed by the user equipment, wherein the measurements are used to identify characteristics associated with specific TRPs; circuitry configured to perform: selecting a cell from the plurality of cells based on the number of TRPs that are associated with each of the plurality of cells; and circuitry configured to perform: initiating a connection establishment with the cell that has been selected.

[0047] The following are applicable to each (e.g., one or more, including all) of the above eleventh to fifteenth aspects.

[0048] In some examples, the user equipment is further caused to perform: obtaining information about the plurality of cells, wherein each of the plurality of cells are candidates for serving the user equipment.

[0049] In some examples, the characteristics associated with a TRP comprises at least one of: a configuration for an antenna associated with a TRP, or a reference signal associated with a TRP.

[0050] In some examples, a TRP is determined to be detected for a respective cell when a measured signal associated with the TRP is above a threshold level.

[0051] In some examples, a respective TRP is determined to be detected for a respective cell when it is determined that a reference signal, RS, of an antenna port associated with the respective TRP is detected with different antenna panels of the user equipment.

[0052] In some examples, the user equipment is further caused to perform: when the user equipment is configured with RSs of antenna ports that are associated with a set of TRPs that share the same time and frequency resources, performing a detection of RSs of antenna ports associated with the set of TRPs in order to detect the TRPs.

[0053] In some examples, the performing of the detection of RSs of antenna ports associated with the set of TRPs comprises: detecting a strongest interferer and corresponding channel estimates; emulating the strongest interferer using the detected antenna ports associated with corresponding sequences and the channel estimates; and subtracting the strongest regenerated interfere from a received signal.

[0054] In some examples, the user equipment is further caused to perform: based on the configured RSs associated with the set of TRPs, determining antenna port-specific channel estimates of RSs; based on the channel estimates, determining reference signal received powers, RSRPs, of the antenna ports and TRP-specific channel estimates; selecting a TRP from the set of TRPs with the highest RSRP value and subtracting an emulated received signal that is associated with the TRP with the highest RSRP.

[0055] In some examples, the antenna port specific channel estimates of reference signal resources are determined using a least square estimation between a received signal and known TRP-specific sequences.

[0056] A computer product stored on a medium may cause an apparatus to perform the methods as described herein.

[0057] A non-transitory computer readable medium comprising program instructions, that, when executed by an apparatus, cause the apparatus to perform the methods as described herein.

[0058] An electronic device may comprise apparatus as described herein.

[0059] Various other aspects and further embodiments are also described in the following detailed description and in the attached claims.

[0060] According to some aspects, there is provided the subject matter of the independent claims. Some further aspects are defined in the dependent claims. The embodiments that do not fall under the scope of the claims are to be interpreted as examples useful for understanding the disclosure.

[0061] List of Abbreviations: AF: Application Function AMF: Access and Mobility Management Function AN: Access Network BS: Base Station CN: Core Network DCI: Downlink control information DL: Downlink eNB: eNodeB gNB: gNodeB lloT: Industrial Internet of Things LTE: Long Term Evolution NEF: Network Exposure Function NG-RAN: Next Generation Radio Access Network NF: Network Function NR: New Radio NRF: Network Repository Function NW: MAC: MS: Network Medium access control Mobile Station Multiple-transmit / receive point mTRP: 5 PCF Policy Control Function PDSCH: Physical downlink shared channel PDCCH: Physical downlink control channel PUSCH: Physical uplink shared channel PUCCH: Physical uplink control channel 10 PLMN: Public Land Mobile Network RAN: Radio Access Network RF: Radio Frequency RRC: Radio resource control RS: Reference signal 15 RSRP: Reference signal received power RSRQ: Reference signal received quality SFN: Single frequency network SMF: Session Management Function SSB: Synchronisation signal block 20 STxMP: Simultaneous Transmission with Multi-Panel TRP: Transmission and reception point UE: User Equipment UDR: Unified Data Repository UDM: Unified Data Management 25 UL: Uplink UPF: User Plane Function 3GPP: 3rd Generation Partnership Project 5G: 5th Generation 5G Core network 30 5G-AN: 5G Radio Access Network 5GS: 5G System BRIEF DESCRIPTION OF DRAWINGS

[0062] Some examples will now be described, by way of illustrative and non-limiting example 35 only, with reference to the accompanying drawings in which:

[0063] FIG. 1 shows a schematic representation of a 5G communication system;

[0064] FIG. 2 shows a schematic representation of an apparatus for the 5G communication system of FIG. 1;

[0065] FIG. 3 shows a schematic representation of a communication device;

[0066] FIG. 4 shows schematic representation communication systems supporting transmissions according to multi-TRP operation;

[0067] FIG. 5 shows an example flowchart for a user equipment performing a cell selection procedure;

[0068] FIG. 6 shows another example flowchart for a user equipment performing a cell selection procedure;

[0069] FIG. 7 shows another example flowchart for a user equipment performing a cell selection procedure;

[0070] FIG. 8 shows an example method flow diagram performed by an apparatus;

[0071] FIG. 9 shows an example method flow diagram performed by an apparatus;

[0072] FIG. 10 shows another example method flow diagram performed by an apparatus; and

[0073] FIG. 11 shows a schematic representation of an apparatus. DETAILED DESCRIPTION

[0074] In multiple transmission and reception point (multi-TRP or mTRP) operation, a serving cell is able to schedule downlink (DL) transmissions to a communication device (e.g., a user equipment (UE)) from two or more TRPs. A UE is also able to provide uplink (UL) transmissions to two or more TRPs. A TRP is a network entity (or network element) that is capable of transmitting and receiving radio signals to / from a UE, e.g., according to physical layer properties and parameters inherent to that network entity. A network entity such as a base station, or gNodeB, is an example of a TRP. Other examples of TRPs include: macrocells (large coverage areas served by powerful base stations), small cells (compact base stations deployed in densely populated or indoor areas), pico-cells, femto-cells (even smaller cells for localized coverage, remote radio heads (distributed units connected to a central base station). Often, multi-TRP provides better coverage, higher reliability and / or better data rates for physical downlink shared channel (PDSCH), physical downlink control channel (PDCCH), physical uplink shared channel (PUSCH), and physical uplink control channel (PUCCH) compared to single TRP operations.

[0075] There are two different operational modes to schedule multi-TRP PDSCH transmissions, namely single downlink control information (single-DCI) and multi-DCI. For both modes, control of uplink and downlink operation may be done by the physical layer and / or the medium access control (MAC) layer within the configuration provided by the radio resource control (RRC) layer. In single-DCI mode, the UE is scheduled by the same DCI for all TRPs and in multi-DCI mode, the UE is scheduled by independent DCIs from each TRP.

[0076] There are two different modes for multi-TRP PDCCH transmissions, namely PDCCH repetition and single frequency network (SFN)-based PDCCH transmission. In both modes, the UE can receive two PDCCH transmissions, one from each TRP, carrying the same DCI. In PDCCH repetition mode, the UE may receive the two PDCCH transmissions carrying the same DCI from two linked search spaces, wherein each search space is associated with a different CORESET. In SFN-based PDCCH transmission mode, the UE may receive the two PDCCH transmissions carrying the same DCI from a single search space / CORESET using different transmission configuration indication (TCI) states.

[0077] For multi-TRP PUSCH repetition, according to indications in a single DCI or in a semistatic configured grant provided over RRC, a UE performs PUSCH transmission of the same contents toward two TRPs with corresponding beam directions associated with different spatial relations. For multi-TRP PUCCH repetition, a UE performs PUCCH transmission of the same contents toward two TRPs with corresponding beam directions associated with different spatial relations.

[0078] When in inter-cell multi-TRP operation, for multi-DCI PDSCH transmission, one or more TCI states may be associated with a synchronisation signal block (SSB) with a physical layer cell identifier (PCI) different from the serving cell PCI. The activated TCI states may be associated with, at most, one PCI different from the serving cell PCI at one time.

[0079] For inter-cell and intra-cell multi-DCI multi-TRP operation, up to two timing advance groups (TAGs) with associated TAG IDs may be configured per serving cell. Each UL / joint TCI state is associated with a TAG ID and the UE applies the timing advance of the TAG ID associated with the UL / joint TCI state utilized for UL transmission.

[0080] For single-DCI multi-TRP Simultaneous Transmission with Multi-Panel (STxMP) spatial domain multiplexing (SDM) PUSCH transmission, different layers of one PUSCH are separately transmitted towards two TRPs. For single-DCI multi-TRP STxMP SFN PUSCH transmission, same layers of one PUSCH are transmitted towards two TRPs. For multi-DCI based multi-TRP STxMP PUSCH+PUSCH transmission, two PUSCHs are transmitted towards two TRPs. For single-DCI multi-TRP STxMP SFN PUCCH transmission, one PUCCH is transmitted towards two TRPs.

[0081] FIG. 4 shows schematic representation communication systems supporting transmissions according to multi-TRP operation.

[0082] As described above, there is single-DCI mTRP (depicted in FIG. 4A), as well as multi-DCI mTRP(depicted in FIG. 4B). As shown in FIG. 4A, there is a first TRP 401 and a second TRP 403 which are connected to a first UE 405. The first TRP 401 transmits a first PDCCH (labelled as ‘PDCCH #1’) with first DCI (labelled as ‘DCI #1’) to the first UE 405. The first TRP 401 also transmits a first PDSCH (labelled as ‘PDSCH #T) to the first UE 405. The second TRP 403 also transmits the first PDSCH (labelled as ‘PDSCH #T) to the first UE 405. In this manner, the first UE 405 is scheduled by the same DCI (i.e., DCI #1) for both TRPs 401, 403.

[0083] As shown in FIG. 4B, there is a third TRP 451 and a fourth TRP 453 which are connected to a second UE 455. The third TRP 451 transmits a first PDCCH (labelled as ‘PDCCH #T) with first DCI (labelled as ‘DCI #T) to the second UE 455. The third TRP 451 also transmits a first PDSCH (labelled as ‘PDSCH #T) to the second UE 455. The fourth TRP 453 transmits a second PDCCH (labelled as ‘PDCCH #2’) with second DCI (labelled as ‘DCI #2’) to the second UE 455. The fourth TRP 453 also transmits a second PDSCH (labelled as ‘PDSCH #2’) to the second UE 455. In this manner, the UE 405 is scheduled by the different DCIs for each TRPs 451, 453.

[0084] When communication devices (e.g., UEs) are connected to a serving cell, the communication devices are also performing measurements of other neighbouring cells to determine whether the signal quality would be improved if connected to another cell. Similarly, when a communication device does not currently have access to a network (i.e., no serving cell), then the communication device may utilise performed measurements to determine suitable cells for an initial access.

[0085] Communication devices may determine which cell from candidate cells is most suitable to attempt to connect to using a cell selection criterion (or cell ranking). The cell selection criterion often takes into account the signal strength (e.g., RSRP) and / or signal quality (e.g., RSRQ) associated with the candidate cells.

[0086] For example, in a cell ranking procedure (3GPP TS 38.304) for5G NR: Intra-frequency and equal priority inter-frequency cell Reselection criteria, wherein the cell-ranking criterion Rs for the serving cell and Rn for neighbouring cells is defined by: Rs = Qmeas,s +Qhyst - Qoffsettemp Rn = Qmeas.n -Qoffset - Qoffsettemp

[0087] where Qmeas = RSRP measurement quantity used in cell re-selections, Qoffset = For intra-frequency: equal to (Qoffset s,n) if (Qoffset s,n) is valid, otherwise equal to zero. For inter-frequency: equal to (Qoffset s,n) + (Qoffset frequency) if (Qoffset s,n) is valid, otherwise this is equals to (Qoffset frequency), and (Qoffset temp) = Offset temporarily applied to a cell as specific in TS 38.331.

[0088] A UE may perform ranking of all cells that fulfil a cell selection criterion. The cells may be ranked by calculating the R values, e.g., using averaged RSRP results. A UE may perform cell reselection to the highest ranked cell. In such cases, the UE may reselect the new cell if the following conditions are met: the new cell is better than the serving cell according to the cell reselection criteria during a time interval, and more than 1 second has elapsed since the UE camped on the current serving cell.

[0089] However, even though a new serving cell is determined based on the signal strength or signal quality, the ‘best’ serving cell may not always been selected by the UE. There may be other cells that would be more suitable for serving the UE.

[0090] One or more of the following examples aim to address one or more of the problems that have been identified above.

[0091] In examples, there is provided a method performed by an apparatus (e.g., a user equipment) that comprises: obtaining, for each of a plurality of cells, information that indicates a number of transmission and reception points, TRPs, that are associated with each cell, wherein each of the plurality of cells are candidates for serving the user equipment, and selecting a cell from the plurality of cells based on the number of TRPs that are associated with each of the plurality of cells. The method further comprises initiating a connection establishment with the cell that has been selected.

[0092] In examples, there is provided a method performed by an apparatus (e.g., a user equipment), that comprises: detecting, for each of a plurality of cells, a number of transmission and reception points, TRPs, that are associated with each cell, wherein each of the plurality of cells are candidates for serving the user equipment, wherein the number of TRPs that have been detected for each cell is based on measurements performed by the user equipment, wherein the measurements are used to identify characteristics associated with specific TRPs. The method further comprising selecting a cell from the plurality of cells based on the number of TRPs that are associated with each of the plurality of cells, and initiating a connection establishment with the cell that has been selected.

[0093] In examples, there is provided a method performed by an apparatus (e.g., user equipment), that comprises: obtaining, for each of a plurality of cells, information that indicates a number of transmission and reception points, TRPs, that are associated with each cell, wherein each of the plurality of cells are candidates for serving the user equipment. The method further comprising: selecting a cell from the plurality of cells based on a value for ranking that is associated with each of the plurality cells, wherein, for each cell, the value for ranking is determined based on the number of TRPs that are associated with the respective cell. The method further comprising: initiating a connection establishment with the cell that has been selected.

[0094] These examples will be described in more detail below, alongside FIGS. 5 to 11.

[0095] Before explaining the examples above in greater detail, an example communication device (as shown in FIG. 3) that is capable of performing a cell ranking or cell selection procedure will be described. The communication device is part of a communication system (as shown in FIG. 1). The communication device is able to communicate with one or more of the entities of the communication system (as shown in FIG. 1) via an apparatus (as shown in FIG. 2), which may be part of / comprised in a base station. A base station may provide a cell that serves the communication device, or may provide a candidate cell that the communication device may connect to in a cell re-selection procedure, or initial connection procedure.

[0096] Certain general aspects of the communication system and the communication device are briefly explained with reference to FIGS. 1 to 3 to assist in understanding the technology underlying the described examples.

[0097] FIG. 1 shows a schematic representation of a 5G communication system 100. In this manner, FIG. 1 illustrates an example of a communication network to which examples disclosed herein may be applied. The communication network or a cellular communication network may comprise a network node 110 providing one or more cells, such as cell 100, and a network node 112 providing one or more other cells, such as cell 102. Each cell may be, e.g., a macro cell, a micro cell, femto, or a pico cell, for example. The cell may define a coverage area or a service area of the corresponding access node.

[0098] The network node 110 may provide a user equipment (UE) 120 (one or more UEs) with wireless access to the communication network. The wireless access may comprise downlink (DL) communication from the network node to the UE 120 and uplink (UL) communication from the UE 120 to the network node. Examples of uplink channels comprise physical uplink control channel (PUCCH) for transmitting control information and physical uplink shared channel (PUSCH) for transmitting data towards the network. Examples of downlink channels comprise physical downlink control channel (PDCCH) for transmitting control information and physical downlink shared channel (PDSCH) for transmitting data towards the user equipment.

[0099] There may be a plurality of UEs 120, 122 in the system. Each of them may be served by the same or by different network nodes 110, 112. UE may be configured with dual connectivity (DC), wherein the UE, e.g. UE 120, may be connected to multiple network nodes 110, 112. The UEs 120, 122 may communicate with each other, in case device-to-device (D2D) communication interface is established between them via a so-called sidelink (SL). Such D2D communications may be referred to as machine-to-machine, peer-to-peer (P2P) communications, or vehicle-to-vehicle (V2V), for example.

[0100] In the case of multiple network nodes in the communication network, the network nodes may be connected to each other via an interface. LTE specifications call such an interface as X2 interface. An interface between an LTE node and a 5G node, or between two 5G nodes may be called Xn interface.

[0101] The network nodes 110 and 112 may be further connected via another interface to a core network 116 of the communication network. The LTE specifications specify the core network as an evolved packet core (EPC), and the core network may comprise e.g. a mobility management entity (MME) and a gateway node. The MME may handle mobility of terminal devices in a tracking area encompassing a plurality of cells and handle signalling connections between the terminal devices and the core network. The gateway node may handle data routing in the core network and to / from the terminal devices. The 5G specifications specify the core network as a 5G core (5GC). The 5G core may comprise e.g. an access and mobility management function (AMF) and a user plane function / gateway (UPF) and other functions. The AMF may handle termination of non-access stratum (NAS) signalling, NAS ciphering &integrity protection, registration management, connection management, mobility management, access authentication and authorization, security context management. The UPF node may support packet routing and forwarding, packet inspection and quality of service (QoS) handling, for example.

[0102] FIG. 2 illustrates an example of an apparatus 200. The apparatus 200 may be for the 5G communication system of FIG. 1. The apparatus 200 may be for controlling a function of one or more network entities and / or network functions, such as the entities of the 5G-RAN or the 5GC as illustrated on FIG. 1. The apparatus 200 comprises at least one random access memory (RAM) 211a, at least one read only memory (ROM) 211b, at least one processor 212, 213 and an input / output interface 214. The at least one processor 212, 213 is coupled to the RAM 211a and the ROM 211b. The at least one processor 212, 213 may be configured to execute an appropriate software code 215. The software code 215 may for example allow to perform one or more steps to perform one or more of the present aspects or examples. The software code 215 may be stored in the ROM 211b. The apparatus 200 may be interconnected with another apparatus 200 controlling another entity / function of the 5G-AN or the 5GC. . In some examples, apparatus 200 may be configured to provide one or more functions of the 5G-AN or the 5GC. For example, apparatus 200 may be configured to perform at least some functionality of a particular function of the 5G-AN or the 5GC. For example, apparatus 200 may be configured to operate as a particular function of the 5G-AN or the 5GC. In alternative examples, apparatus 200 may be configured to perform at least some functionality of two or more functions of the 5G-AN and / or the 5GC. For example, apparatus 200 may be configured to operate as two or more functions of the 5G-AN and / or the 5GC. The apparatus 200 may comprise one or more circuits, or circuitry (not shown) which may be configured to perform one or more of the present aspects or examples.

[0103] FIG. 3 illustrates an example of a communication device 300. The communication device 300 may be similar to the communication device 102 illustrated in FIG. 1. The communication device 300 may be provided by any device capable of sending and receiving radio signals. Non-limiting examples of a communication device 300 are a user equipment, a terminal, a mobile station (MS) or mobile device such as a mobile phone or what is known as a ’smart phone’, a computer provided with a wireless interface card or other wireless interface facility (e.g., USB dongle), a personal data assistant (PDA) or a tablet provided with wireless communication capabilities, a machine-type communications (MTC) device, a Cellular Internet of things (CloT) device, or a terrestrial / maritime / aerial vehicle such as a car, a truck, a boat, an air plane, or a drone, or any combinations of these or the like. The communication device 300 may provide, for example, communication of data for carrying communications. The communications may be one or more of voice, electronic mail (email), text message, multimedia, data, machine data and so on.

[0104] The communication device 300 may receive signals over an air or radio interface 307 via appropriate apparatus for receiving and may transmit signals via appropriate apparatus for transmitting radio signals. In FIG. 3, a transceiver apparatus is designated schematically by block 306. The transceiver apparatus 306 may be provided for example by means of a radio part and associated antenna arrangement. The antenna arrangement may be arranged internally or externally to the mobile device.

[0105] The communication device 300 may be provided with at least one processor 301, at least one memory ROM 302a, at least one RAM 302b and other possible components 303 for use in software and hardware aided execution of tasks it is designed to perform, including control of access to and communications with access systems and other communication devices. The at least one processor 301 is coupled to the RAM 302b and the ROM 302a. The at least one processor 301 may be configured to execute an appropriate software code 308. The software code 308 may for example allow to perform one or more of the present aspects. The software code 308 may be stored in the ROM 302a. The communication device 300 may comprise one or more circuits, or circuitry (not shown) which may be configured to perform one or more of the present aspects or examples.

[0106] The processor, storage and other relevant control apparatus may be provided on an appropriate circuit board and / or in chipsets. This feature is denoted by reference 304. The communication device may optionally have a user interface such as keypad 305, touch sensitive screen or pad, combinations thereof or the like. Optionally one or more of a display, a speaker and a microphone may be provided depending on the type of the device.

[0107] In one or more of the following examples, the number of TRPs that are associated with a (candidate) cell is utilised to determine a cell ranking, e.g., for an intra and / or inter-frequency cell selection / cell reselection.

[0108] FIG. 5 shows an example flowchart for a user equipment performing a cell selection procedure.

[0109] At S501, a UE (or other communication device) obtains information that indicates a plurality of cells, wherein each of the plurality of cells is a candidate to be serving cell for the UE. Stated differently, the UE identifies the plurality of cells as candidates to be serving cell for the UE. The UE may perform measurements (e.g. on reference signals (RS)) to identify to the plurality of cells. In other examples, the UE may receive the information used to identify the plurality of cells. The plurality of cells may be cells that neighbour the serving cell of the UE, or neighbour the location of the UE (if the UE does not have a serving cell).

[0110] The UE determines, for each of the plurality of cells, a value for ranking based on measurements. The measurements may be performed by the UE, wherein the measurements are associated with each of the plurality of cells. The value for ranking may be referred to as the ‘R’ value, as described above. The UE may utilise RSRP and / or RSRQ values associated with each of the plurality of cells to determine (or calculate) the value for ranking for the respective cell. In this manner, the value for ranking is based on the measurements (e.g., RSRP, or RSRQ).

[0111] The value for ranking may be given any suitable name, such as, ‘R value’, ‘value for quality’, ‘value for signal quality’, or simply ‘value’. These terms may be used interchangeably. Herein, the ‘value for ranking’ will be referred to as the ‘R value’.

[0112] The UE determines which cell from the plurality of cells has the highest (or largest) R value (based on the determined R value for each cell). The cell determined to have the highest R value will be referred to as the ‘highest cell’ (or highest ranking cell). It should be understood that any suitable label may be used to describe the cell determined to have the highest R value from the plurality of cells.

[0113] At S502, the UE determines which of the cells of the plurality of cells have a (determined) R value within a threshold value of the R value of the highest cell. The threshold value may be received from a network entity (e.g., gNB). In other examples, the threshold value is pre-configured at the UE, or otherwise determined by the UE itself. The threshold value may be given any suitable name. For example, instead of ‘threshold value’, the term ‘relative threshold’, ‘TRP threshold’, or ‘relative_TRP’ may be used.

[0114] For example, if the threshold value is 3 decibels (dB), then the cells within the threshold value will be higher or lower than the R value of the highest cell by 3 dB. In some examples the threshold value is applied to determine the cells that are within the threshold value range of the highest cell. It should be understood that 3 dB is given as an example only. In other examples, the threshold value is higher, or lower, than 3 dB.

[0115] At S503, for each of the cells determined to be within the threshold value, the UE obtains information that indicates a number of TRPs that are associated with each cell. It should be understood that the cells determined to be within the threshold value includes the highest cell itself. In this manner, the set of cell for S503 includes the highest cell and the cells determined to have an R value within the threshold value of the R value of the highest cell.

[0116] One or more of the cells determined to be within the threshold value may support multi-TRP. In this manner, these cells may be associated with a plurality of TRPs (i.e., multi-TRP). One or more of the cells determined to be within the threshold value may not support multi-TRP. Cells that do not support multi-TRP will have a single (i.e., 1) TRP associated with the cell.

[0117] In some examples, a UE may consider a cell to be a valid candidate when the number of TRPs for a cell is above a threshold number of TRPs. In some examples, a TRP may be considered as a ‘detected’ TRP when at least one DL RS associated with the TRP is detected and is above a threshold signal quality value.

[0118] In some examples, the obtaining of the information comprises the UE detecting (or determining) the number of TRPs associated with each of the cells that are within the threshold value. The UE may perform one or more measurements in order to detect the number of TRPs. This will be described in more detail below.

[0119] In some examples, the obtaining of the information comprises the UE receiving the information from a network entity (e.g., via the serving cell of the UE).

[0120] In some examples, a TRP that is associated with a cell refers to a detected TRP of a cell. Stated differently, a TRP that has been detected for a cell.

[0121] In some examples, a TRP that is associated with a cell refers to a detected TRP of a cell from one or more TRPs configured for use in a cell.

[0122] In some examples, associated TRPs of a cell refers to a number of supported / configured TRPs in a cell. In some examples, a TRP is associated with a cell but is not detected by a UE. In some examples, a TRP is associated with a cell, and is detected for the cell (by a UE) when the detected cell is above a threshold strength / quality. For example, a first cell may be associated with four TRPs (i.e., is configured with four TRPs / comprises four TRPs). However, dependent on measurements performed by a UE, the UE may detect (only) two of the four TRPs (due to the signal quality measured by the UE of the four TRPs). It should be appreciated that this is an example only.

[0123] In some examples, the terms ‘detected’ and ‘associated’ may be used interchangeably in the context of TRPs and their relationship with cells.

[0124] The threshold value may be configured by system information (SI), in some examples. In other examples, the threshold value is received from a network with radio resource control (RRC) signalling.

[0125] In the example of FIG. 5, it is assumed that the TRPs that are associated with each cell have been detected by the UE (‘detected TRPs’). A detected TRP may be a TRP that has both been discovered by the UE and determined to have a suitable strength and / or quality. A detected TRP may refer to a TRP that has an associated DL RS signal quality above a threshold signal quality value. A detected TRP may refer to a TRP that has an average signal quality of associated DL RSs above a threshold signal quality value.

[0126] At S504, the UE determines which cell, or cells, have the largest number of detected (or associated) TRPs. The UE determines whether multiple cells (i.e., more than 1 cell) has the same (largest) number of TRPs.

[0127] When the determination at S504 is ‘NO’ (i.e., there is only a single cell that has the largest number of TRPs), the flow continues to S505. When the determination at S504 is ‘YES’ (i.e., multiple cells have the same largest number of TRPs), the flow continues to S506.

[0128] At S505, the UE selects the cell that has the largest number of (detected) TRPs. In this manner, the cell that has been selected is within the threshold value of the highest cell (or is the highest cell itself) and has the largest number of (detected) TRPs.

[0129] The UE initiates (or triggers) a connection establishment with the cell that has been selected. In some examples, the UE has a current serving cell, and then initiates a cell reselection with the cell that has been selected (e.g., a handover).

[0130] At S506, from the multiple cells which have the largest number of TRPs, the UE selects the cell that has the higher associated R value. The UE then initiates (or triggers) a connection establishment with the cell that has been selected.

[0131] FIG. 6 shows another example flowchart for a user equipment performing a cell selection procedure.

[0132] S501 to S505 as described for FIG. 5 are also present in the flowchart of FIG. 6. These common steps are given the same labelling in FIG. 5 and FIG. 6. When the determination at S504 is ‘NO’ (i.e., there is only a single cell that has the largest number of TRPs), the flow continues to S505. When the determination at S504 is ‘YES’ (i.e., multiple cells have the same largest number of TRPs), the flow continues to S606.

[0133] At S606, for the multiple cells which have the largest number of TRPs, the UE determines how many beams are associated with each of the cells. An associated beam may be considered to be a discovered (or measured) beam that is measured to be above a beam threshold value. In this manner, the UE determines a number of beams, for each cell, that are considered as “usable” or “suitable”. Stated differently, the beams considered as “usable” or “suitable” may have quality above a certain beam threshold value. The beam threshold value may be configured by network (e.g., via system information (or via dedicated signalling). The beam threshold value may also be a detection threshold value. Stated differently, the beam threshold value may be a threshold signal quality value of when a beam (downlink reference signal) may be considered to be detected. In some examples, the number of beams (per cell) is determined across all TRPs for that cell. In other examples, the number of beams is the highest number of beams for one TRP.

[0134] In some examples, the UE compares the number of (suitable) beams for a cell to a threshold number. The UE may consider a cell to be a valid candidate when the number of beams is above the threshold number of beams. Stated differently, for the cell (or a TRP of a cell) to be considered by the UE, the cell (or TRP) is to have more (suitable) beams than the threshold number of beams. The threshold number of beams may be configured by SI, or may be received from a network with RRC signalling.

[0135] In some examples, a beam is determined to be associated with a cell when measurements associated with the beam are above a threshold strength (or threshold quality).

[0136] The ‘threshold number’ may be given any suitable name. For example, instead of ‘threshold number, the term ‘beam threshold’, or ‘relative_Beam’ may be used.

[0137] At S607, the UE determines which cell, or cells, have the largest number of (detected) beams. The UE determines whether multiple cells (i.e., more than 1 cell) have the same (largest) number of beams.

[0138] When the determination at S607 is ‘NO’ (i.e., there is only a single cell that has the largest number of associated beams), the flow continues to S608. When the determination at S607 is ‘YES’ (i.e., multiple cells have the same largest number of beams), the flow continues to S608.

[0139] At S608, the UE selects the cell that has the largest number of (detected) beams. In this manner, the cell that has been selected is within the threshold value of the highest cell (or is the highest cell itself), has the largest number of associated TRPs, and has the largest number of beams.

[0140] The UE initiates (or triggers) a connection establishment with the cell that has been selected. In some examples, the UE has a current serving cell, and then initiates a cell reselection with the cell that has been selected (e.g., a handover).

[0141] At S609, when two or more cells have the same (largest) number of (detected) beams, the UE selects the cell from the two or more cells that has the higher R value. The UE initiates (or triggers) a connection establishment with the cell that has been selected.

[0142] FIG. 7 shows another example flowchart for a user equipment performing a cell selection procedure.

[0143] S501 to S502 as described for FIG. 5 are also present in the flowchart of FIG. 7. These common steps are given the same labelling in FIG.5 and FIG. 7.

[0144] At S703, for each of the cells determined to be within the threshold value, the UE determines how many beams are associated with each of the cells. An associated beam may be considered to be a discovered (or measured) beam that is measured to be above a beam threshold value. In this manner, the UE determines a number of beams, for each cell, that are considered as “usable” or “suitable”. Stated differently, the beams considered as “usable” or “suitable” may have quality above a certain beam threshold value.

[0145] In some examples, the number of beams (per cell) is determined across all TRPs for that cell. In other examples, the number of beams is the highest number of beams for one TRP.

[0146] In some examples, the UE compares the number of beams of a cell to a threshold number. The UE may consider a cell to be a valid candidate when the number of beams is above the threshold number of beams.

[0147] In some examples, a beam is determined to be detected in a cell when measurements associated with the beam are above a threshold strength (or threshold quality).

[0148] At S704, the UE determines which cell, or cells, have the largest number of (detected) beams. The UE determines whether multiple cells (i.e., more than 1 cell) have the same (largest) number of associated beams.

[0149] When the determination at S704 is ‘NO’ (i.e., there is only a single cell that has the largest number of associated beams), the flow continues to S705. When the determination at S704 is ‘YES’ (i.e., multiple cells have the same largest number of beams), the flow continues to S706.

[0150] At S705, the UE selects the cell that has the largest number of beams. In this manner, the cell that has been selected is within the threshold value of the highest cell (or is the highest cell itself), and has the largest number of beams.

[0151] The UE initiates (or triggers) a connection establishment with the cell that has been selected. In some examples, the UE has a current serving cell, and then initiates a cell reselection with the cell that has been selected (e.g., a handover).

[0152] At S706, the UE obtains information that indicates a number of TRPs associated with each cell (with the largest number of associated beams).

[0153] One or more of the cells with the largest number of beams may support multi-TRP. In this manner, these cells may be associated with a plurality of TRPs (i.e., multi-TRP) (e.g., with multiple TRPs that the UE determines it has detected with at least one beam / DL RS). One or more of the cells may not support multi-TRP. Cells that do not support multi-TRP will have a single (i.e., 1) TRP associated with the cell.

[0154] In some examples, the obtaining of the information comprises: the UE detecting (or determining) the number of TRPs associated with each of the cells. The UE may perform one or more measurements in order to detect the number of TRPs. This will be described in more detail below.

[0155] In some examples, the obtaining of the information comprises the UE receiving the information from a network entity (e.g., via the serving cell of the UE).

[0156] In some examples, the UE determines, for each cell, whether the number of detected TRPs for the respective cell is above a threshold amount of TRPs. The UE may consider the respective cell to be a valid candidate when the number of detected TRPs is above the threshold amount of TRPs.

[0157] In some examples, the UE determines, for each cell, whether the number of TRPs associated (i.e. configured) with the respective cell is above a threshold amount of TRPs. The UE may consider the respective cell to be a valid candidate when the number of detected TRPs is above the threshold amount of TRPs.

[0158] In the example of FIG. 7, it is assumed that the TRPs that are associated with each cell have been detected by the UE (‘detected TRPs’). A detected TRP may be a TRP that has both been discovered by the UE and determined to have a suitable strength and / or quality. A detected TRP may refer to a TRP that has an associated DL RS signal quality above a threshold signal quality value. A detected TRP may refer to a TRP that has an average signal quality of associated DL RSs above a threshold signal quality value.

[0159] At S707, the UE determines which cell, or cells, have the largest number of TRPs. The UE determines whether multiple cells (i.e., more than 1 cell) has the same (largest) number of TRPs.

[0160] When the determination at S707 is ‘NO’ (i.e., there is only a single cell that has the largest number of TRPs), the flow continues to S708. When the determination at S707 is ‘YES’ (i.e., multiple cells have the same largest number of TRPs), the flow continues to S709.

[0161] At S708, the UE selects the cell that has the largest number of (detected) TRPs. In this manner, the cell that has been selected is within the threshold value of the highest cell (or is the highest cell itself), has the higher number of (detected) beams, and has the largest number of (detected) TRPs. The UE then initiates (or triggers) a connection establishment with the cell that has been selected.

[0162] At S709, from the multiple cells which have the largest number of (detected) TRPs, the UE selects the cell that has the higher associated R value. The UE then initiates (or triggers) a connection establishment with the cell that has been selected.

[0163] In some examples, a cell is accounted for, by a UE (e.g., associated with the flowcharts of any of FIGS. 5 to 7) in cell ranking for TRP based re-selection or considered suitable for TRP based cell selection when a specified number of TRPs are considered as detected. A TRP may be considered detected by the UE when a quality detected for the TRP exceeds a certain threshold (and therefore be deemed detected). The specified number of TRPs may be preconfigured, in some examples. In other examples, the specified number is signalled by the network to the UE.

[0164] In this manner, the number of TRPs associated with a cell, that has been detected by a UE, may not be accounted for in the cell selection unless the number of TRPs is above the specified number. For example, 2 cells are determined to be within threshold value (of the R value of the highest cell), wherein a first cell has 1 suitable TRP and a second cell has 2 suitable TRPs. However, in this example, the specified number is 3 TRPs. This means that neither the first cell or the second cell is ranked higher or lower relative to each other based on number of TRPs (alone).

[0165] In some examples, a UE determines an R value for each candidate cell for a cell selection, wherein the R value for each cell is calculated based on the number of TRPs that are associated with (or detected for) each respective cell. The R value may be increased based on the number of associated TRPs.

[0166] The R value (for each cell) may be increased by a set value (herein referred to as ‘X’ dB) for each TRP detected that is in addition to a first TRP (each cell will be associated with at least one TRP). For example, when the UE detects 2 TRPs for a first cell, the R value of the R cell is increased by X dB. Stated differently, an initial R value for the first cell is determined based on measurements related to the first cell. The initial R value of the first cell is then scaled (or altered, etc) based on the number of TRPs associated with the first cell. In another example, when the UE detects 2 or more TRPs for a first cell, the R value is increased by a set value (e.g., X dB). In another example, when a UE detects that N TRPs are associated with a first cell, then the R value for the first cell is increased using the following: R = R + (N-1) * XdB. Stated differently, for a cell that is associated with a number, N, of TRPs, the initial R value is increased by X dB multiplied by N-1. In another example, an initial R value of a first cell is increased by a UE based on a difference between the number of TRPs that are associated with the first cell and the number of TRPs associated with a cell that is currently serving the user equipment.

[0167] Once the initial R value for each cell has been scaled based on the number of TRPs associated with (or detected for) each respective cell, the UE selects a cell from the candidate cells. The UE selects the cell with the highest R value (after scaling). The UE then initiates (or triggers) a connection establishment with the cell that has been selected.

[0168] In some examples, a UE determines an R value for each TRP that is associated with (or detected for) a candidate cell for a cell selection, such that a signal quality / signal strength of individual TRPs is utilised to rank the candidate cells. The UE may obtain information that indicates how many TRPs are associated with each of a plurality of cells. The UE may detect how many TRPs are associated with each of the plurality of cells (e.g., perform measurements to discover TRPs for a cell and then determine whether the discovered TRP is “suitable” or “usable”). Each of the plurality of cells are candidate cells to serve the UE. For any of the cells that do not support multi-TRP, then the number of TRPs associated with that cell will be 1. The UE then, per cell, determines an R value for each of the (associated / detected) TRPs. In this manner, a measured signal strength and / or signal quality associated with each TRP may be utilised to determine each R value. Based on the R values that have been determined, the UE identifies (or determines) the TRP that has the highest R value. The UE then selects the cell that is associated with the TRP that has the highest R value. The R value may be selected for each cell based on the R value of at least one TRP. The UE then initiates (or triggers) a connection establishment with the cell that has been selected.

[0169] As described above (e.g., in FIGS. 5 to 7), a UE obtains information about a number of TRPs that are associated with a cell. The UE may perform measurements on signals being transmitted by nearby cells / TRPs (e.g., reference signals). In some examples, the UE determines the number of TRPs based on a configuration of an antenna (e.g., a configuration of an antenna panel) that associated with a TRP. The configuration of the antenna may be considered to be a characteristic associated with the TRP. Different configurations for antennas of a TRP may allow a UE to differentiate between different TRPs, and allow a UE to determine a number of different TRPs. In other examples, the UE determines the number of TRPs based on a RSs associated with a TRP. The RS (or RSs) associated with a TRP may be considered to be a characteristic associated with the TRP.

[0170] In some examples, a UE may consider that a TRP has been detected (for the purposes of ranking for cell selection, as described above) when an RS of an antenna port associated with a TRP is detected with different antenna panels of the UE.

[0171] In some examples, when a UE is configured with RSs of antenna ports associated with set of TRPs sharing the same time and frequency resources, the UE may perform the detection of RSs of antenna ports associated with the set of TRPs by applying non-linear receiver processing for received RSs. This may include, for example, the following:

[0172] S1: Based on configured RSs associated with set of TRPs, a UE determines channel estimates, specific to an antenna port, for RSs. For example, by using least square estimation between a received signal and known TRP specific sequences.

[0173] S2: Using the results of S1, the UE determines an RSRP of the antenna port and TRP-specific channel estimates.

[0174] S3: The UE selects the highest RSRP value of a TRP and subtracts an emulated received signal (e.g., TRP specific sequence times channel estimates across all RX antenna ports) associated with the highest RSRP for the TRP.

[0175] S4: The UE repeats S1 to S3 in order to detect all TRPs that have RSRP above a configured threshold.

[0176] In this manner, as shown in S1 to S4, the UE subtracts known sequences in order to remove interference.

[0177] In some examples, in an alternative to the non-linear receiver processing described above, the UE may perform the detection of RSs of antenna ports associated with the set of TRPs as follows. The UE may perform a detection of a strongest interferer and then determine corresponding channel estimates. The UE then performs a re-generating (or emulating) of the strongest interferer (e.g., by using detected antenna ports associated with corresponding sequences as well as the channel estimates). Following this, the strongest re-generated interferer is subtracted from a received signal at the UE. Then, a second strongest interferer associated with the antenna port and corresponding sequence is detected by the UE. The UE then performs a re-generating (or emulating) of the second strongest interference, and then subtracted from the received signal. The iterative process is continued until all known TRPs / indicated TRPs are detected.

[0178] As described above (e.g., in FIGS. 5 to 7), a UE obtains information about a number of TRPs that are associated with a cell. The UE may obtain this information using any suitable method, e.g., detecting the number of associated TRPs by performing measurements. Measurements performed on different signals may allow the UE to identify different TRPs (e.g., signals may comprise characteristics that associate the signal with a specific TRP). For example, a characteristic associated with a TRP is a configuration for an antenna associated with the TRP. Another example of a characteristic associated with a TRP is reference signal associated with the TRP.

[0179] In some examples, the signal quality of a TRP may be determined by a UE based on an average quality of downlink reference signals (DL RSs) associated with a certain TRP. The average quality may be compared to a threshold to determine whether the signal quality of a TRP is suitable. Stated differently, the UE may consider a TRP to be detected when the average quality is above the threshold. The threshold may be network configured.

[0180] In some examples, the signal quality of a TRP may be determined by a UE based on a quality of a (DL) RS of an antenna port that is associated with a certain TRP. For example, the signal quality of the TRP may be determined based on the measured RS with the highest quality. In another example, the signal quality of the TRP may be determined based on the RS (or RSs) having a quality above a threshold. Each antenna port is associated with a specific set of reference signals such that the channel over which a symbol is transmitted on that antenna port may be distinguished from the channel over which another symbol is conveyed on the same antenna port.

[0181] In some examples, a detection of a TRP may be determined based on a signal quality threshold which may be: a DL RS detection threshold, a network configured threshold value (e.g. ‘TRP_detection_threshold_reselection’), or a network configured maximum power difference between a highest quality measured RS and measured RSs having quality above a detection threshold. The network may configure a minimum number of RSs associated with a certain TRP to be above a configured detection threshold in order to be ‘detected’.

[0182] In some examples, a UE considers that a TRP is detected when the signal quality of the TRP is above a threshold.

[0183] In some examples, the signal quality (or R value) of a TRP may be associated with a measured receive level (e.g., RSRP or RSRQ) of the TRP.

[0184] In some examples, a beam detection performed by a UE may be based on a signal quality threshold which may be: a DL RS detection threshold, a network configured threshold value e.g., ‘beam_detection_threshold’), or a network configured relative difference between a highest quality measured RS and a measured RSs (e.g., and having a having quality above a detection threshold).

[0185] In some examples, system information provided to a UE may indicate whether the UE should perform a cell selection based on: the number of TRPs associated with a cell, or the number of beams associated with a cell.

[0186] In some examples, when the threshold value (TRP threshold) is accessible to a UE (e.g., has been received from a network), then the UE selects a cell based on the number of associated TRPs.

[0187] In some examples, when the threshold value is accessible to a UE (e.g., has been received from a network) and the UE also supports mTRP, then the UE selects a cell based on the number of associated TRPs.

[0188] In some examples, when both the threshold value and the threshold number are accessible to a UE number and the UE also supports mTRP, then the UE selects a cell based on the number of associated TRPs.

[0189] In some examples, when both the threshold value and the threshold number are accessible to a UE number and the UE also supports mTRP, then the UE selects a cell based on the number of associated TRPs and the number of associated beams.

[0190] In some examples, when the threshold value is not accessible to a UE, the UE does not select a cell based on the TRP level information.

[0191] In some examples, the threshold value that is used to determine cells that are within threshold of the cell with highest R value, is also reused for TRP detection. In some examples, at least one DL RS associated with a TRP is determined to be within the threshold value of the cell with the highest R value to be considered as a detected TRP.

[0192] In some examples, the threshold value that is used to determine cells that are within threshold of the cell with highest R value, is also reused for TRP detection and beam selection.

[0193] In some examples, the threshold value is used: to determine cells that are within threshold of the cell with highest R value, and to determine which beams associated with a cell have a sufficient strength / quality.

[0194] FIG. 8 shows an example method flow performed by an apparatus. The apparatus may be a communication device, such as a terminal device, user equipment, or other mobile device. In other examples, the apparatus may be comprised in a communication device (e.g., UE).

[0195] In S801, the method comprises: obtaining, for each of a plurality of cells, information that indicates a number of transmission and reception points, TRPs, that are associated with each cell, wherein each of the plurality of cells are candidates for serving the user equipment.

[0196] In S803, the method comprises: selecting a cell from the plurality of cells based on the number of TRPs that are associated with each of the plurality of cells.

[0197] In S805, the method comprises: initiating a connection establishment with the cell that has been selected.

[0198] It should be understood that, in some examples, one or more additional method steps are included in the method flow of FIG. 8 and are performed by the apparatus. In some examples, one or more of the method steps of FIG. 8 detailed above may not be performed, or may be performed in a different order.

[0199] FIG. 9 shows an example method flow performed by an apparatus. The apparatus may be a communication device, such as a terminal device, user equipment, or other mobile device. In other examples, the apparatus may be comprised in a communication device (e.g., UE).

[0200] In S901, the method comprises: obtaining, for each of a plurality of cells, information that indicates a number of transmission and reception points, TRPs, that are associated with each cell, wherein each of the plurality of cells are candidates for serving the user equipment.

[0201] In S903, the method comprises: selecting a cell from the plurality of cells based on a value for ranking that is associated with each of the plurality cells, wherein, for each cell, the value for ranking is determined based on the number of TRPs that are associated with the respective cell.

[0202] In S905, the method comprises: initiating a connection establishment with the cell that has been selected.

[0203] It should be understood that, in some examples, one or more additional method steps are included in the method flow of FIG. 9 and are performed by the apparatus. In some examples, one or more of the method steps of FIG. 9 detailed above may not be performed, or may be performed in a different order.

[0204] FIG. 10 shows an example method flow performed by an apparatus. The apparatus may be a communication device, such as a terminal device, user equipment, or other mobile device. In other examples, the apparatus may be comprised in a communication device (e.g., UE).

[0205] In S1001, the method comprises: detecting, for each of a plurality of cells, a number of transmission and reception points, TRPs, that are associated with each cell, wherein each of the plurality of cells are candidates for serving the user equipment, wherein the number of TRPs that have been detected for each cell is based on measurements performed by the user equipment, wherein the measurements are used to identify characteristics associated with specific TRPs.

[0206] In S1003, the method comprises: selecting a cell from the plurality of cells based on the number of TRPs that are associated with each of the plurality of cells.

[0207] In S1005, the method comprises: initiating a connection establishment with the cell that has been selected.

[0208] It should be understood that, in some examples, one or more additional method steps are included in the method flow of FIG. 10 and are performed by the apparatus. In some examples, one or more of the method steps of FIG. 10 detailed above may not be performed, or may be performed in a different order.

[0209] FIG. 11 shows a schematic representation of an apparatus. FIG. 11 shows, byway of example, a block diagram of an apparatus 10. The apparatus 10 comprises, for example, at least one processor 12 and at least one memory 14 storing instructions 15 that, when executed by the at least one processor, cause the apparatus 10 at least to perform the method or methods as disclosed herein, and any of the embodiments thereof. In an example, the at least one memory and the instructions (e.g. a computer program code, software), are configured, with the at least one processor, to cause the apparatus 10 to perform the method or methods as disclosed herein, and any of the embodiments thereof.

[0210] A processor 12 may comprise circuitry, or be constituted as circuitry or circuitries, the circuitry or circuitries being configured to perform phases of methods in accordance with example embodiments described herein. As used in this application, the term “circuitry” may refer to one or more or all of the following: (a) hardware-only circuit implementations, such as implementations in only analog and / or digital circuitry, and (b) combinations of hardware circuits and software, such as, as applicable: (i) a combination of analog and / or digital hardware circuit(s) with software / firmware and (ii) any portions of hardware processor(s) with software (including digital signal processor(s)), software, and memory(ies) that work together to cause an apparatus, such as a user equipment, to perform various functions) and (c) hardware circuit(s) and or processor(s), such as a microprocessor(s) or a portion of a microprocessor(s), that requires software (e.g., firmware) for operation, but the software may not be present when it is not needed for operation. This definition of circuitry applies to all uses of this term in this application, including in any claims. As a further example, as used in this application, the term circuitry also covers an implementation of merely a hardware circuit or processor (or multiple processors) or portion of a hardware circuit or processor and its (or their) accompanying software and / or firmware. The term circuitry also covers, for example and if applicable to the particular claim element, a baseband integrated circuit or processor integrated circuit for a mobile device or a similar integrated circuit in server, a cellular network device, or other computing or network device.

[0211] The memory 14 may be implemented using any suitable data storage technology. The memory may comprise a database for storing data. The memory 14 may be at least in part external to apparatus 10 but accessible to apparatus 10.

[0212] The instructions 15 may be comprised in a computer readable medium or a non-transitory computer readable medium. A term non-transitory, as used herein, is a limitation of the medium itself (i.e. tangible, not a signal) as opposed to a limitation on data storage persistency (e.g. random access memory, RAM, vs. read only memory, ROM).

[0213] For example, the apparatus 10 is a terminal device, such as the UE associated with the FIGS. 5 to 7. As another example, the apparatus is comprised in such a terminal device, e.g. as a chipset configured to control the terminal device. The apparatus 10 may be caused or configured to perform at least the method of any of FIGS. 8 to 10 and / or any one or more of the examples described.

[0214] As another example, the apparatus 10 is a network node, e.g. the network entity (gNB) described above. In another embodiment, the apparatus is comprised in such a network node, e.g. as a chipset configured to control the network node. The apparatus 10 may comprise one or more entities of any of protocol layers, such as a MAC entity, an RRC entity, an RLC entity, a PDCP entity or a PHY entity.

[0215] The apparatus 10 comprises a radio interface 16. The radio interface 16 may provide the apparatus 10 with communication capabilities. The radio interface 16 may comprise a receiver configured to receive information in accordance with at least one cellular or non-cellular standard. The radio interface 16 may comprise a transmitter configured to transmit information in accordance with at least one cellular or non-cellular standard. The receiver may comprise more than one receiver. The transmitter may comprise more than one transmitter. The radio interface 16 may comprise a transceiver configured to receive and transmit information in accordance with at least one cellular or non-cellular standard. The transceiver may comprise more than one transceiver.

[0216] The apparatus 10 may comprise a user interface 18 comprising, for example, at least one of a keypad, a microphone, a touch display, a display, a speaker, etc. The user interface 18 may be used to control the apparatus by the user. The user interface 18 may be external to the apparatus 10. For example, the apparatus 10 may be connected to another device, such as a computer, either via wireless or wired connection, and the apparatus 10 is controlled by the user via the computer.

[0217] In an embodiment, at least some of the processes described herein may be carried out by an apparatus comprising means for carrying out at least some of the described processes. Means for performing method steps as disclosed herein may include software and / or hardware components of the apparatus 10. For example, the at least one processor 12, the memory 14, and the computer program code form means for carrying out the method or methods as disclosed herein, and any of the embodiments thereof. As used herein the term “means” is to be construed in singular form, i.e. referring to a single element, or in plural form, i.e. referring to a combination of single elements. Therefore, terminology “means for [performing A, B, C]”, is to be interpreted to cover an apparatus in which there is only one means for performing A, B and C, or where there are separate means for performing A, B and C, or partially or fully overlapping means for performing A, B, C. Further, terminology “means for performing A, means for performing B, means for performing C” is to be interpreted to cover an apparatus in which there is only one means for performing A, B and C, or where there are separate means for performing A, B and C, or partially or fully overlapping means for performing A, B, C. It is noted that while the above describes example embodiments, there are several variations and modifications which may be made to the disclosed solution without departing from the scope of the present invention.

[0218] The examples may thus vary within the scope of the attached claims. In general, some embodiments may be implemented in hardware or special purpose circuits, software, logic or any combination thereof. For example, some aspects may be implemented in hardware, while other aspects may be implemented in firmware or software which may be executed by a controller, microprocessor or other computing device, although embodiments are not limited thereto. While various embodiments may be illustrated and described as block diagrams, flow charts, or using some other pictorial representation, it is well understood that these blocks, apparatus, systems, techniques or methods described herein may be implemented in, as non limiting examples, hardware, software, firmware, special purpose circuits or logic, general purpose hardware or controller or other computing devices, or some combination thereof.

[0219] The examples may be implemented by computer software stored in a memory and executable by at least one data processor of the involved entities or by hardware, or by a combination of software and hardware. Further in this regard it should be noted that any procedures may represent program steps, or interconnected logic circuits, blocks and functions, or a combination of program steps and logic circuits, blocks and functions. The software may be stored on such physical media as memory chips, or memory blocks implemented within the processor, magnetic media such as hard disk or floppy disks, and optical media such as for example DVD and the data variants thereof, CD.

[0220] The term “non-transitory”, as used herein, is a limitation of the medium itself (i.e. tangible, not a signal) as opposed to a limitation on data storage persistency (e.g. RAM vs ROM).

[0221] As used herein, “at least one of the following:” and “at least one of: ” and similar wording, where the list of two or more elements are joined by “and”, or “or”, mean at least any one of the elements, or at least any two or more of the elements, or at least all of the elements.

[0222] The memory may be of any type suitable to the local technical environment and may be implemented using any suitable data storage technology, such as semiconductor-based memory devices, magnetic memory devices and systems, optical memory devices and systems, fixed memory and removable memory. The data processors may be of any type suitable to the local technical environment, and may include one or more of general purpose computers, special purpose computers, microprocessors, digital signal processors (DSPs), application specific integrated circuits (ASIC), gate level circuits and processors based on multi core processor architecture, as non-limiting examples.

[0223] As used herein, the terms “means for”, “means for performing operations including”, “means configured to perform operations including”, or “means configured to perform” (or similar) may be any means that are suitable for performing the feature(s). The “means” may be configured to perform one or more of the functions and / or method steps previously described. For example, the “means” may include one or more of: at least one processor, at least one memory, transceiver circuitry, antenna circuitry, etc. It should be understood that these are provided as non-limiting examples.

[0224] Alternatively, or additionally some examples may be implemented using circuitry. The circuitry may be configured to perform one or more of the functions and / or method steps previously described. That circuitry may be provided in the base station and / or in the communications device.

[0225] As used in this application, the term “circuitry” may refer to one or more or all of the following: (a) hardware-only circuit implementations (such as implementations in only analogue and / or digital circuitry); (b) combinations of hardware circuits and software, such as: (i) a combination of analogue and / or digital hardware circuit(s) with software / firmware and (ii) any portions of hardware processor(s) with software (including digital signal processor(s)), software, and memory(ies) that work together to cause an apparatus, such as the communications device or base station to perform the various functions previously described; and (c) hardware circuit(s) and or processor(s), such as a microprocessor(s) or a portion of a microprocessor(s), that requires software (e.g., firmware) for operation, but the software may not be present when it is not needed for operation.

[0226] This definition of circuitry applies to uses of the term “means” in this application, including in any claims. As a further example, as used in this application, the term circuitry also covers an implementation of merely a hardware circuit or processor (or multiple processors) or portion of a hardware circuit or processor and its (or their) accompanying software and / or firmware. The term circuitry also covers, for example integrated device. The term circuitry also covers, for example and if applicable to the particular claim element, a baseband integrated circuit or processor integrated circuit for a mobile device or a similar integrated circuit in a server, a cellular network device, or other computing or network device.

[0227] The foregoing description has provided by way of exemplary and non-limiting examples a full and informative description of some embodiments. However, various modifications and adaptations may become apparent to those skilled in the relevant arts in view of the foregoing description, when read in conjunction with the accompanying drawings and the appended claims. However, all such and similar modifications of the teachings will still fall within the scope as defined in the appended claims.

Claims

1. A user equipment comprising:means for detecting, for each of a plurality of cells, a number of transmission and reception points, TRPs, that are associated with each cell,wherein each of the plurality of cells are candidates for serving the user equipment, wherein the number of TRPs that have been detected for each cell is based on measurements performed by the user equipment, wherein the measurements are used to identify characteristics associated with specific TRPs;means for selecting a cell from the plurality of cells based on the number of TRPs that are associated with each of the plurality of cells; andmeans for initiating a connection establishment with the cell that has been selected.

2. The user equipment according to claim 1, wherein the characteristics associated with a TRP comprises at least one of: a configuration for an antenna associated with a TRP, or a reference signal associated with a TRP.

3. The user equipment according to claim 1 or claim 2, wherein a TRP is determined to be detected for a respective cell when a measured signal associated with the TRP is above a threshold level.

4. The user equipment according to any of claims 1 to 3, wherein a respective TRP is determined to be detected for a respective cell when it is determined that a reference signal, RS, of an antenna port associated with the respective TRP is detected with different antenna panels of the user equipment.

5. The user equipment according to any of claims 1 to 4, further comprising:means for, when the user equipment is configured with RSs of antenna ports that are associated with a set of TRPs that share the same time and frequency resources, performing a detection of RSs of antenna ports associated with the set of TRPs in order to detect the TRPs.

6. The user equipment according to claim 5, wherein the performing of the detection of RSs of antenna ports associated with the set of TRPs comprises:detecting a strongest interferer and corresponding channel estimates;emulating the strongest interferer using the detected antenna ports associated with corresponding sequences and the channel estimates; andsubtracting the strongest regenerated interfere from a received signal.

7. The user equipment according to claim 5, further comprising:means for, based on the configured RSs associated with the set of TRPs, determining antenna port-specific channel estimates of RSs;means for, based on the channel estimates, determining reference signal received powers, RSRPs, of the antenna ports and TRP-specific channel estimates;means for selecting a TRP from the set of TRPs with the highest RSRP value and subtracting an emulated received signal that is associated with the TRP with the highest RSRP.

8. The user equipment according to claim 7, wherein the antenna port specific channel estimates of reference signal resources are determined using a least square estimation between a received signal and known TRP-specific sequences.

9. A method performed by a user equipment, the method comprising:detecting, for each of a plurality of cells, a number of transmission and reception points, TRPs, that are associated with each cell,wherein each of the plurality of cells are candidates for serving the user equipment,wherein the number of TRPs that have been detected for each cell is based on measurements performed by the user equipment, wherein the measurements are used to identify characteristics associated with specific TRPs;selecting a cell from the plurality of cells based on the number of TRPs that are associated with each of the plurality of cells; andinitiating a connection establishment with the cell that has been selected.

10. The method according to claim 9, wherein the characteristics associated with a TRP comprises at least one of: a configuration for an antenna associated with a TRP, ora reference signal associated with a TRP.

11. The method according to claim 9 or claim 10, wherein a TRP is determined to be detected for a respective cell when a measured signal associated with the TRP is above a threshold level.

12. The method according to any of claims 9 to 11, wherein a respective TRP is determined to be detected for a respective cell when it is determined that a reference signal,RS, of an antenna port associated with the respective TRP is detected with different antenna panels of the user equipment.

13. The method according to any of claims 9 to 12, further comprising:when the user equipment is configured with RSs of antenna ports that are associated with a set of TRPs that share the same time and frequency resources, performing a detection of RSs of antenna ports associated with the set of TRPs in order to detect the TRPs.

14. The method according to claim 13, wherein the performing of the detection of RSs of antenna ports associated with the set of TRPs comprises:detecting a strongest interferer and corresponding channel estimates;emulating the strongest interferer using the detected antenna ports associated with corresponding sequences and the channel estimates; andsubtracting the strongest regenerated interfere from a received signal.

15. The method according to claim 13, further comprising:based on the configured RSs associated with the set of TRPs, determining antenna port-specific channel estimates of RSs;based on the channel estimates, determining reference signal received powers, RSRPs, of the antenna ports and TRP-specific channel estimates;selecting a TRP from the set of TRPs with the highest RSRP value and subtracting an emulated received signal that is associated with the TRP with the highest RSRP.

16. The method according to claim 15, wherein the antenna port specific channel estimates of reference signal resources are determined using a least square estimation between a received signal and known TRP-specific sequences.

17. A computer program comprising instructions, which when executed by a user equipment, cause the user equipment to perform at least the following:detecting, for each of a plurality of cells, a number of transmission and reception points, TRPs, that are associated with each cell, wherein each of the plurality of cells are candidates for serving the user equipment, wherein the number of TRPs that have been detected for each cell is based on measurements performed by the user equipment, wherein the measurements are used to identify characteristics associated with specific TRPs;selecting a cell from the plurality of cells based on the number of TRPs that are associated with each of the plurality of cells; andinitiating a connection establishment with the cell that has been selected.36

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