TECHNICAL FIELD

[0001] This invention relates generally to paging a user equipment in a wireless communication system and, more specifically, relates to paging using beam parameters for beam-based operation.

BACKGROUND

[0002] This section is intended to provide a background or context to the invention disclosed below. The description herein may include concepts that could be pursued, but are not necessarily ones that have been previously conceived, implemented or described. Therefore, unless otherwise explicitly indicated herein, what is described in this section is not prior art to the description in this application and is not admitted to be prior art by inclusion in this section. Abbreviations that may be found in the specification and/or the drawing figures are defined below, at the beginning of the detailed description section.

[0003] In Release 17 (Rel-17), it is expected there will be an introduction of New Radio- Light (NR-Light) to address use cases that cannot be met by NR Enhanced Mobile Broadband (eMBB), Ultra-Reliable Low Latency Communication (URLLC), or Enhanced Machine Type Communication (eMTC) / Narrowband IoT (NB-IoT). NR-Light is also referred to as NR-based IoT or NR-IoT. NR-Light will support the following requirements:

[0004] 1) Higher data rate and reliability and lower latency than eMTC and NB-IoT;

[0005] 2) Lower cost/complexity and longer battery life than NR eMBB; and

[0006] 3) Wider coverage than eMBB.

[0007] Specifically, NR-Light will address the following objectives and use case:

[0008] 1) Moderate data rates up to, e.g., 100 Mbps to support, e.g., live video feed, visual production control, and/or process automation;

[0009] 2) Moderate latency of around 10-30 ms to support, e.g., remote drone operation, cooperative farm machinery, time-critical sensing and feedback, remote vehicle operation;

[0010] 3) Low complexity device with module cost comparable to Long Term Evolution

(LTE); [0011] 4) Coverage enhancement of 10-15 dB compared to eMBB;

[0012] 6) Low power consumption with battery life, e.g., 2-4 times longer than eMBB; and

[0013] 7) Possible positioning accuracy of 30 cm to 1 m to support, e.g., indoor asset tracking, coordinated vehicle control, remote monitoring.

[0014] NR-Light will be supported in both frequency ranges FR1 (450-6000 MHz) and FR2 (24250 - 52600 MHz). In FR2, beam-based or multi-beam operation (i.e., using narrow beams to communicate with a user equipment, UE) is the typical operation mode. Using narrow beams for communication can cause problems, e.g., with paging.

BRIEF SUMMARY

[0015] This section is intended to include examples and is not intended to be limiting.

[0016] In an exemplary embodiment, a method is disclosed that includes, at a base station in a wireless network, wherein the base station communicates with multiple user equipment using multiple beams, in response to receiving a paging request intended for a selected one of the multiple user equipment, retrieving beam parameter information comprising an indication of a selected one of the multiple beams that was last-used by the selected user equipment to communicate with the base station. The method includes sending paging from the base station toward the selected user equipment using the selected beam and based on the beam parameter information.

[0017] An additional exemplary embodiment includes a computer program, comprising code for performing the method of the previous paragraph, when the computer program is run on a processor. The computer program according to this paragraph, wherein the computer program is a computer program product comprising a computer-readable medium bearing computer program code embodied therein for use with a computer. Another example is the computer program according to this paragraph, wherein the program is directly loadable into an internal memory of the computer.

[0018] An exemplary apparatus includes one or more processors and one or more memories including computer program code. The one or more memories and the computer program code are configured to, with the one or more processors, cause the apparatus to perform operations comprising: at a base station in a wireless network, wherein the base station communicates with multiple user equipment using multiple beams, in response to receiving a paging request intended for a selected one of the multiple user equipment, retrieving beam parameter information comprising an indication of a selected one of the multiple beams that was last-used by the selected user equipment to communicate with the base station; and sending paging from the base station toward the selected user equipment using the selected beam and based on the beam parameter information.

[0019] An exemplary computer program product includes a computer-readable storage medium bearing computer program code embodied therein for use with a computer. The computer program code includes: code for at a base station in a wireless network, wherein the base station communicates with multiple user equipment using multiple beams, in response to receiving a paging request intended for a selected one of the multiple user equipment, retrieving beam parameter information comprising an indication of a selected one of the multiple beams that was last-used by the selected user equipment to communicate with the base station; and code for sending paging from the base station toward the selected user equipment using the selected beam and based on the beam parameter information.

[0020] In another exemplary embodiment, an apparatus comprises: means, at a base station in a wireless network, wherein the base station communicates with multiple user equipment using multiple beams, in response to receiving a paging request intended for a selected one of the multiple user equipment, for retrieving beam parameter information comprising an indication of a selected one of the multiple beams that was last-used by the selected user equipment to communicate with the base station; and means for sending paging from the base station toward the selected user equipment using the selected beam and based on the beam parameter information.

[0021] In an exemplary embodiment, a method is disclosed that includes, at a network node in a wireless network, receiving a paging message intended for a selected user equipment registered via a corresponding base station in the wireless network. The method includes determining by the network node based on the paging message the selected user equipment, its corresponding base station, and a beam parameter indicating at least a selected one of multiple beams last used by the base station to communicate with the selected user equipment. The method also includes sending a paging request from the network node toward the base station indicating the selected user equipment and the beam parameter.

[0022] An additional exemplary embodiment includes a computer program, comprising code for performing the method of the previous paragraph, when the computer program is run on a processor. The computer program according to this paragraph, wherein the computer program is a computer program product comprising a computer-readable medium bearing computer program code embodied therein for use with a computer. Another example is the computer program according to this paragraph, wherein the program is directly loadable into an internal memory of the computer.

[0023] An exemplary apparatus includes one or more processors and one or more memories including computer program code. The one or more memories and the computer program code are configured to, with the one or more processors, cause the apparatus to perform operations comprising: at a network node in a wireless network, receiving a paging message intended for a selected user equipment registered via a corresponding base station in the wireless network; determining by the network node based on the paging message the selected user equipment, its corresponding base station, and a beam parameter indicating at least a selected one of multiple beams last used by the base station to communicate with the selected user equipment; and sending a paging request from the network node toward the base station indicating the selected user equipment and the beam parameter.

[0024] An exemplary computer program product includes a computer-readable storage medium bearing computer program code embodied therein for use with a computer. The computer program code includes: code for, at a network node in a wireless network, receiving a paging message intended for a selected user equipment registered via a corresponding base station in the wireless network; code for determining by the network node based on the paging message the selected user equipment, its corresponding base station, and a beam parameter indicating at least a selected one of multiple beams last used by the base station to communicate with the selected user equipment; and code for sending a paging request from the network node toward the base station indicating the selected user equipment and the beam parameter.

[0025] In another exemplary embodiment, an apparatus comprises: means, at a network node in a wireless network, for receiving a paging message intended for a selected user equipment registered via a corresponding base station in the wireless network; means for determining by the network node based on the paging message the selected user equipment, its corresponding base station, and a beam parameter indicating at least a selected one of multiple beams last used by the base station to communicate with the selected user equipment; and means for sending a paging request from the network node toward the base station indicating the selected user equipment and the beam parameter.

BRIEF DESCRIPTION OF THE DRAWINGS [0026] In the attached Drawing Figures:

[0027] FIG. 1 is a block diagram of one possible and non-limiting exemplary system in which the exemplary embodiments may be practiced;

[0028] FIG. 2 illustrates an example of beam-based operation;

[0029] FIG. 3 illustrates an example of paging for beam-based operation;

[0030] FIG. 4 is a signaling diagram of an exemplary embodiment for paging using beam parameters for beam-based operation, in accordance with an exemplary embodiment; and

[0031] FIGS. 5, 6, and 7 are logic flow diagrams performed by a UE, base station, and AMF, respectively, for paging using beam parameters for beam-based operation, in accordance with exemplary embodiments.

DETAILED DESCRIPTION OF THE DRAWINGS

[0032] The following abbreviations that may be found in the specification and/or the drawing figures are defined as follows:

[0033] 3 GPP third generation partnership project

[0034] 5G fifth generation

[0035] 5GC 5G core network

[0036] AMF access and mobility management function

[0037] BW bandwidth

[0038] CE control element

[0039] CIoT Cellular Internet of Things

[0040] CN core network [0041] CU central unit

[0042] DCI Downlink Control Information

[0043] DL downlink

[0044] DU distributed unit

[0045] eMBB Enhanced Mobile Broadband

[0046] eMTC Enhanced Machine Type Communication

[0047] eNB (or eNodeB) evolved Node B (e.g., an LTE base station)

[0048] EN-DC E-UTRA-NR dual connectivity

[0049] en-gNB or En-gNB node providing NR user plane and control plane protocol terminations towards the UE, and acting as secondary node in EN-DC

[0050] EPC evolved packet core

[0051] E-UTRA evolved universal terrestrial radio access, i.e., the LTE radio access technology

[0052] FDM frequency-division multiplex (or multiplexing)

[0053] FR Frequency Range

[0054] FR1 FR one, 450-6000 MHz

[0055] FR2 FR two, 24250 - 52600 MHz

[0056] gNB (or gNodeB) base station for 5G/NR, i.e., a node providing NR user plane and control plane protocol terminations towards the UE, and connected via the NG interface to the 5GC

[0057] I/F interface

[0058] IMSI International Mobile Subscriber Identity

[0059] IoT Internet of Things

[0060] LTE long term evolution

[0061] MAC medium access control

[0062] MIB Master Information Block

[0063] MME mobility management entity

[0064] MPDCCH MTC Physical Downlink Control Channel

[0065] MTC machine-type communications [0066] NB-IoT Narrowband IoT

[0067] ng or NG next generation

[0068] ng-eNB or NG-eNB next generation eNB

[0069] NR new radio

[0070] N/W or NW network

[0071] PDCCH Physical Downlink Control Channel

[0072] PDCP packet data convergence protocol

[0073] PDSCH Physical Downlink Data Channel

[0074] PHY physical layer

[0075] PO Paging Occasion

[0076] PRB Physical Resource Block

[0077] P-RNTI Paging Radio Network Temporary Identifier

[0078] RAN radio access network

[0079] RE Resource Element

[0080] RF radio frequency

[0081] Rel release

[0082] RLC radio link control

[0083] RNTI Radio Network Temporary Identifier

[0084] RRH remote radio head

[0085] RRC radio resource control

[0086] RS Reference Signal

[0087] RSRP Reference Signal Received Power

[0088] RU radio unit

[0089] Rx receiver

[0090] SDAP service data adaptation protocol

[0091] SGW serving gateway

[0092] SIB System Information Block

[0093] SMF session management function

[0094] SSB Synchronization Signal Block

[0095] TDM time-division multiplex (or multiplexing) [0096] TS technical specification

[0097] Tx transmitter

[0098] UE user equipment (e.g., a wireless, typically mobile device) [0099] UPF user plane function

[00100] URLLC Ultra-Reliable Low Latency Communication

[00101] The word“exemplary” is used herein to mean“serving as an example, instance, or illustration.” Any embodiment described herein as“exemplary” is not necessarily to be construed as preferred or advantageous over other embodiments. All of the embodiments described in this Detailed Description are exemplary embodiments provided to enable persons skilled in the art to make or use the invention and not to limit the scope of the invention which is defined by the claims.

[00102] The exemplary embodiments herein describe techniques for paging using beam parameters for beam-based operation. Additional description of these techniques is presented after a system into which the exemplary embodiments may be used is described.

[00103] Turning to FIG. 1, this figure shows a block diagram of one possible and non-limiting exemplary system in which the exemplary embodiments may be practiced. A user equipment (UE) 110, radio access network (RAN) node 170, and network element(s) 190 are illustrated. In FIG. 1, a user equipment (UE) 110 is in wireless communication with a wireless network 100, which many also be called a communication system and may be a cellular communication system. A UE is a wireless, typically mobile device that can access a wireless network. The UE 110 includes one or more processors 120, one or more memories 125, and one or more transceivers 130 interconnected through one or more buses 127. Each of the one or more transceivers 130 includes a receiver, Rx, 132 and a transmitter, Tx, 133. The one or more buses 127 may be address, data, or control buses, and may include any interconnection mechanism, such as a series of lines on a motherboard or integrated circuit, fiber optics or other optical communication equipment, and the like. The one or more transceivers 130 are connected to one or more antennas 128. The one or more memories 125 include computer program code 123. The UE 110 includes a paging module 140, comprising one of or both parts 40-1 and/or 40- 2, which may be implemented in a number of ways. The paging module 40 may be implemented in hardware as paging module 40-1, such as being implemented as part of the one or more processors 120. The paging module 40-1 may be implemented also as an integrated circuit or through other hardware such as a programmable gate array. In another example, the paging module 40 may be implemented as paging module 40-2, which is implemented as computer program code 123 and is executed by the one or more processors 120. That is, the one or more memories 125 and the computer program code 123 may be configured to, with the one or more processors 120, cause the user equipment 110 to perform one or more of the operations as described herein. The UE 110 communicates with RAN node 170 via a wireless link 111.

[00104] The RAN node 170 is a base station that provides access by wireless devices such as the UE 110 to the wireless network 100. The RAN node 170 may be, for instance, a base station for 5G, also called New Radio (NR). In 5G, the RAN node 170 may be a NG-RAN node, which is defined as either a gNB or an ng-eNB. A gNB is a node providing NR user plane and control plane protocol terminations towards the UE, and connected via the NG interface to a 5GC (e.g., the network element(s) 190). In the text below, the RAN node 170 is considered primarily to be a gNB, although this is not required and is for exposition. The ng- eNB is a node providing E-UTRA user plane and control plane protocol terminations towards the UE, and connected via the NG interface to the 5GC. The NG-RAN node may include multiple gNBs, which may also include a central unit (CU) (gNB-CU) 196 and distributed unit(s) (DUs) (gNB-DUs), of which DU 195 is shown. Note that the DU may include or be coupled to and control a radio unit (RU). The gNB-CU is a logical node hosting RRC, SDAP and PDCP protocols of the gNB or RRC and PDCP protocols of the en-gNB that controls the operation of one or more gNB-DUs. The gNB-CU terminates the FI interface connected with the gNB-DU. The FI interface is illustrated as reference 198, although reference 198 also illustrates a link between remote elements of the RAN node 170 and centralized elements of the RAN node 170, such as between the gNB-CU 196 and the gNB-DU 195. The gNB-DU is a logical node hosting RLC, MAC and PHY layers of the gNB or en-gNB, and its operation is partly controlled by gNB-CU. One gNB-CU supports one or multiple cells. One cell is supported by only one gNB- DU. The gNB-DU terminates the FI interface 198 connected with the gNB-CU. Note that the DU 195 is considered to include the transceiver 160, e.g., as part of an RU, but some examples of this may have the transceiver 160 as part of a separate RU, e.g., under control of and connected to the DU 195. The RAN node 170 may also be an eNB (evolved NodeB) base station, for LTE (long term evolution), or any other suitable base station.

[00105] The RAN node 170 includes one or more processors 152, one or more memories 155, one or more network interfaces (N/W I/F(s)) 161, and one or more transceivers 160 interconnected through one or more buses 157. Each of the one or more transceivers 160 includes a receiver, Rx, 162 and a transmitter, Tx, 163. The one or more transceivers 160 are connected to one or more antennas 158. The one or more memories 155 include computer program code 153. The CU 196 may include the processor(s) 152, memories 155, and network interfaces 161. Note that the DU 195 may also contain its own memory/memories and processor(s), and/or other hardware, but these are not shown.

[00106] The RAN node 170 includes a paging module 150, comprising one of or both parts 150-1 and/or 150-2, which may be implemented in a number of ways. The paging module 150 may be implemented in hardware as paging module 150-1, such as being

implemented as part of the one or more processors 152. The paging module 150-1 may be implemented also as an integrated circuit or through other hardware such as a programmable gate array. In another example, the paging module 150 may be implemented as paging module 150- 2, which is implemented as computer program code 153 and is executed by the one or more processors 152. For instance, the one or more memories 155 and the computer program code 153 are configured to, with the one or more processors 152, cause the RAN node 170 to perform one or more of the operations as described herein. Note that the functionality of the paging module 150 may be distributed, such as being distributed between the DU 195 and the CU 196, or be implemented solely in the DU 195.

[00107] The one or more network interfaces 161 communicate over a network such as via the links 176 and 131. Two or more RAN nodes 170 communicate using, e.g., link 176. The link 176 may be wired or wireless or both and may implement, e.g., an Xn interface for 5G, an X2 interface for LTE, or other suitable interface for other standards.

[00108] The one or more buses 157 may be address, data, or control buses, and may include any interconnection mechanism, such as a series of lines on a motherboard or integrated circuit, fiber optics or other optical communication equipment, wireless channels, and the like. For example, the one or more transceivers 160 may be implemented as a remote radio head (RRH) 195 for LTE or a distributed unit (DU) 195 for gNB implementation for 5G, with the other elements of the RAN node 170 possibly being physically in a different location from the RRH/DU, and the one or more buses 157 could be implemented in part as, e.g., fiber optic cable or other suitable network connection to connect the other elements (e.g., a central unit (CU), gNB-CU) of the RAN node 170 to the RRH/DU 195. Reference 198 also indicates those suitable network link(s).

[00109] It is noted that description herein indicates that“cells” perform functions, but it should be clear that the RAN node that forms the cell will perform the functions. The cell makes up part of a RAN node. That is, there can be multiple cells per RAN node. For instance, there could be three cells for a single carrier frequency and associated bandwidth, each cell covering one-third of a 360 degree area so that the single RAN node’s coverage area covers an approximate oval or circle. Furthermore, each cell can correspond to a single carrier and a RAN node may use multiple carriers. So, if there are three 120 degree cells per earner and two carriers, then the RAN node has a total of 6 cells.

[00110] The wireless network 100 includes an Access and Mobility Management Function (AMF) 190 that can communicate with a Session Management Function (SMF) 148 via link(s) 181, and the SMF 148 can communicate with a User Plane Function (UPF) 146. Such core network functionality for LTE may include MME (Mobility Management Entity)/SGW (Serving Gateway) functionality. The RAN node 170 is coupled via a link 131 to a network element 190. The link 131 may be implemented as, e.g., an NG interface for 5G, or an SI interface for LTE, or other suitable interface for other standards. The network element 190 includes one or more processors 175, one or more memories 171, and one or more network interfaces (N/W I/F(s)) 180, interconnected through one or more buses 185. The AMF 190 includes a paging module 140, comprising one of or both parts 140-1 and/or 140-2, which may be implemented in a number of ways. The paging module 140 may be implemented in hardware as paging module 140-1, such as being implemented as part of the one or more processors 175. The paging module 140-1 may be implemented also as an integrated circuit or through other hardware such as a programmable gate array. In another example, the paging module 140 may be implemented as paging module 140-2, which is implemented as computer program code 173 and is executed by the one or more processors 175. The one or more memories 171 include computer program code 173. The one or more memories 171 and the computer program code 173 may be configured to, with the one or more processors 175, cause the network element 190 to perform one or more operations as described herein.

[00111] The wireless network 100 may implement network virtualization, which is the process of combining hardware and software network resources and network functionality into a single, software-based administrative entity, a virtual network. Network virtualization involves platform virtualization, often combined with resource virtualization. Network virtualization is categorized as either external, combining many networks, or parts of networks, into a virtual unit, or internal, providing network-like functionality to software containers on a single system. Note that the virtualized entities that result from the network virtualization are still implemented, at some level, using hardware such as processors 152 or 175 and memories 155 and 171, and also such virtualized entities create technical effects.

[00112] The computer readable memories 125, 155, and 171 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, flash memory, magnetic memory devices and systems, optical memory devices and systems, fixed memory and removable memory. The computer readable memories 125, 155, and 171 may be means for performing storage functions. The processors 120, 152, and 175 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) and processors based on a multi-core processor architecture, as non-limiting examples. The processors 120,

152, and 175 may be means for performing functions, such as controlling the UE 110, RAN node 170, and other functions as described herein.

[00113] Having thus introduced one suitable but non- limiting technical context for the practice of the exemplary embodiments of this invention, the exemplary embodiments will now be described with greater specificity.

[00114] NR-Light will be supported in both frequency range FR1 (450-6000 MHz) and FR2 (24250 - 52600 MHz). In FR2, beam-based or multi-beam operation (i.e., using narrow beams to communicate with UE) is the typical operation mode. This means that, in FR2, NR uses beam-based operation with many beams per cell. Each beam covers only a fraction of the cell coverage area (e.g., up to 64 SSBs, each associated with a beam, may be configured in a cell). This is illustrated in FIG. 2, where a RAN node 170 creates beams 1 through N, illustrated as beams 210-1, 210-2, ..., 210-N. In addition, RF-beamforming (or analog beamforming) is likely to be used in FR2, which means that only one beam can be formed for the entire system bandwidth. Therefore, UEs are typically TDM instead of FDM (i.e., an entire BW is given to one UE at a time in TDM) unless the gNB 170 can find two UEs 110 to schedule using the same beam.

[00115] For beam-based operation, when a UE 110 is being paged, the gNB 170 does not know which beam to use for the UE, since the UE may be in idle or inactive mode (also called a state) and not reporting beam parameter information to the gNB 170. The gNB 170 can sequentially page the UE using one beam at a time (e.g., which is lower overhead but very high latency), or the gNB 170 can page the UE 110 using all beams (e.g., which is low latency but very high overhead). In addition, when multiple UEs 110 are being paged in the same PO, the PDSCH contains a common paging message for all UEs, as the gNB 170 does not know to which beam each UE belongs.

[00116] Paging for beam-based operation is illustrated in FIG. 3. In this example, there are N subframes 330-1 through 330-N, each of which comprises a corresponding PDCCH 310-1 through 310-N and a corresponding PDSCH 320-1 through 320-N, for a single paging occasion (PO) 300. Each subframe 330-1 through 330-N corresponds to a beam 210-1 through 210-N. It is seen that the paging message, for possibly multiple UEs, must be sent N times, where N is the number of beams 210. For example, each beam may require one subframe to transmit the scheduling control information and paging message. However, in most cases, only one or two UEs are being paged within each paging occasion 300. The overhead for paging is therefore very high for beam-based operation.

[00117] For IoT devices as UEs 110, a substantial fraction of them maybe stationary (e.g., assembly robots, cameras, sensors, and the like). In addition, many devices have low mobility or may be stationary for a long period of time (e.g., factory equipment, spare parts, automated guided vehicles when not being used, and the like). These devices may always have the same preferred beam or rarely change the preferred beam. Current paging does not address this. [00118] Therefore, a method is needed to overcome this high paging overhead when using beam-based operation.

[00119] Previous attempts to address paging or using other elements for paging have been through the following.

[00120] 1) The paging using beaming, as previously described.

[00121] 2) There is already a parameter in the paging message from 5GC informing about“supported band list NR for paging”, which indicates the bands supported by the UE.

[00122] 3) Coverage enhancement (CE) levels: RAN’s last decided CE-level while in connected is stored during idle at the EPC and informed to RAN again in the paging messages.

[00123] 4) The principle of storing RAN-related information in the CN is already known. One example case of this is when a CIoT UE is suspended, see 3 GPP TS 23.401, clause 5.3.4A. See 3GPP TS 23.401 V16.2.0 (2019-03). However, in this case, the UE context is kept in the eNB, UE and the MME.

[00124] However, none of these overcome high paging overhead when using beam-based operation.

[00125] The instant exemplary embodiments address this. For largely stationary UEs, for instance, it would benefit the gNB 170 when paging those UEs to know their preferred beams, as the gNB can send the paging message directly on the preferred beam(s) and not on other beams. And exemplary embodiment herein provides this. For this type and other UEs, information for a previously-used beam or previously-used beams may be stored and retrieved for use for paging the UEs. Other exemplary embodiments are described below.

[00126] As an introduction, FIG. 4 illustrates how an exemplary embodiment can be implemented in the UE and network. FIG. 4 is a signaling diagram of an exemplary embodiment for paging using beam parameters for beam-based operation. Paging call flow impact is shown as an example case. Note the control plane CIoT data is used in step 3, however, this figure is missing the actual data delivery to the UE, because the techniques here have no impact on that.

[00127] As prerequisites (step 0), it is assumed, in RRC CONNECTED mode for the UE, there would be a beam indication and update procedure so that the RAN node 170 is aware of the preferred beam(s) for the UE. In response to UE going into IDLE/INACTIVE mode, this starts the process where the RAN would then send the latest information about the preferred beam(s) to the AMF. Although both IDLE and INACTIVE are considered in this example, it is also possible to start the process in response to only one of these, such as IDLE mode, and not start the process in response to the INACTIVE mode, for instance. It is also noted that 5G vocabulary talks about a registration procedure for a UE, where a registered UE can be in RRC Idle (also indicated as IDLE), RRC Inactive (also indicated as INACTIVE) or RRC Connected (also indicated as CONNECTED) states. So, the UE registers to the network (e.g., the core network) via a base station such as the RAN node 170. The“registered” terminology is used herein, although this is not meant to exclude (and is meant to include) other types of mobility management such as attachment under LTE.

[00128] In step 1, the RAN node 170 informs the AMF 190 of the currently used beams using a message of the UE’s beam parameter with corresponding included information. See, e.g., block 610 in FIG. 6, which illustrates possible information for a beam parameter. This allows the AMF to know which beam (or beams) the UE last-used (e.g., used previously or is currently using). The beam parameter includes information to allow the RAN node 170 to form a beam to the UE.

[00129] In step 2, the AMF 190 stores the beam parameter along with associated RAN ID and UE ID for future use. These IDs allow the AMF 190 to subsequently determine corresponding beam to use for a particular RAN node 170 and UE 110.

[00130] With respect to step 3, subsequently, the UPF 146 sends a forward data message comprising DL data. The SMF 148 in step 4 sends, in response, a Namf_NlN2 MessageTransfer message with corresponding data.

[00131] In step 5, the AMF 190 determines the UE 110 and RAN node 170 for paging using the corresponding stored UE ID and RAN ID, and from this determines the corresponding beam parameter. Subsequently, when the AMF 190 sends an N2 paging message towards the same UE 10 in step 6, the AMF 190 includes the stored beam parameter for that UE 110, e.g., with the RAN ID in the N2 paging request. The beam parameters may be valid only within a certain RAN node, and based on RAN ID, the RAN node can verify whether the received paging parameters are still useful in the current paging case. That is, the beam parameter might not be usable in other RAN nodes, so the RAN ID parameter is included in the corresponding information for the beam parameter in order for the RAN node to detect whether the beam parameter stored in the AMF was detected by the same RAN node or a different one and to decide whether to use the received beam parameter or not. Note that the N2 paging request is a current message, but this message is modified in this example to add the beam parameter. Other options are also possible.

[00132] In step 7, the RAN node 170 determines beam parameters considering also the beam parameter received from the AMF 190. For example, the RAN node 170 may consider the RAN ID associated with the beam parameters when determining the validity of the beam parameter, and only use the beam parameters that were received from the AMF only in response to the beam parameters were earlier stored to AMF by the same RAN ID.

[00133] In step 8, the RAN node 170 pages the UE 110 using the beam locally determined by the RAN node and augmented by the stored beam information that was received from the AMF 190. For instance, the RAN node 170 may determine the beam for paging by enhancing whatever logic the RAN node uses by the additional beam parameter and RAN ID information that is received from the AMF.

[00134] The figure can be modified for other implementations, such as sending DCI on common control channel(s) over specific beam(s) and also using different RNTI associated with the beam(s). Examples of these are described below.

[00135] FIGS. 5, 6, and 7 are implemented by a UE, base station, and AMF, respectively, for paging using beam parameters for beam-based operation. These figures introduce additional examples.

[00136] Turning to FIG. 5, this figure is a logic flow diagram performed by a UE for paging using beam parameters for beam-based operation, in accordance with exemplary embodiments. FIG. 5 illustrates the operation of exemplary methods, a result of execution of computer program instructions embodied on a computer readable memory, functions performed by logic implemented in hardware, and/or interconnected means for performing functions in accordance with exemplary embodiments. The UE 110 performs the blocks in FIG. 5, e.g., under control of the paging module 40. [00137] In one embodiment, in response to the UE going to an IDLE/INACTIVE state from a CONNECTED state, the UE stores last-used beam parameter information. See block 510. Examples of the last-used beam parameter information are illustrated in FIG. 6. This storage in block 510 may not be necessary, because the UE should perform beam selection every time the UE tries to access the network 100, but is added here for completeness.

[00138] The UE 110 in block 520, in response to a command from the network, may store the beam parameter information for the beam the UE is currently using. This is similar to block 510, except caused by the network instead of a transition between states. In block 530, the UE determines whether it is time to search for paging. If not (block 530 = NO), the UE waits. If it is time for paging (block 530 = Yes), the UE in block 540 uses the stored beam parameter information for paging reception. As stated previously, this may not be necessary, because the UE should perform beam selection every time the UE tries to access the system the network 100, but is possible.

[00139] Referring to FIG. 6, this figure is a logic flow diagram performed by a base station (e.g., RAN node 170) for paging using beam parameters for beam-based operation, in accordance with exemplary embodiments. FIG. 6 illustrates the operation of exemplary methods, a result of execution of computer program instructions embodied on a computer readable memory, functions performed by logic implemented in hardware, and/or interconnected means for performing functions in accordance with exemplary embodiments. The RAN node 170 performs the blocks in FIG. 6, e.g., under control of the paging module 150. Below, it is assumed the RAN node is a gNB, but this is merely exemplary.

[00140] In one embodiment (see block 605), in response to RRC signaling from the gNB 170 that moves the UE 110 to an IDLE or INACTIVE state from a CONNECTED state, the gNB 170 stores last-used beam parameter information. Beam parameter information can include (see block 610) one of more of the following: beam configuration such as SSB index, beam index, precoder codebook and precoder index, beamforming coefficients, reference signal configuration, CSI report, antenna port, gNB Tx/Rx point (Transmission Reception Point or TRP, such as an RRH or RU) identifier, or time stamp. This is most beneficial for a stationary or low-mobility UE. So, storing the last-used beam may be dependent on UE subscription information, e.g., if the UE is stationary or if the UE is determined to be stationary (e.g., RSRP measurements are stable, i.e., differences among several measurements less than a threshold, or based on location information). Information about whether a UE is stationary may also be indicated and stored by the AMF. As indicated by block 615, the last-used beam may be a preferred or best beam as reported by the UE in the UE location when the UE was in

CONNECTED state. The preferred beam may be an educated guess to try to re-use the previously used beam. This is of course under assumption that the UE has not moved much since the CONNECTED state or that the beam is sufficiently wide to cover expected UE movement (e.g. a beam may cover the factory area where the UE is confined to). As indicated by block 618, the beam parameter information may be for a last-used beam or last-used few beams, e.g., 2-3 beams. It is possible to send paging to one beam at a time (out of the few), or to send paging on all the last-used beams. As previously indicated, the last-used beam may be a previously- used or currently-used beam.

[00141] In one embodiment, the gNB 170 commands the UE 110 to store the beam parameter information the UE is currently using. See block 620. This could be the RRC message that moves the UE from CONNECTED state to either the IDLE or INACTIVE state. Alternatively, the gNB 170 could also just command the UE to store the information, for instance, in case the information is needed later. As previously indicated, this may not be necessary, because the UE should perform beam selection every time the UE tries to access the network 100.

[00142] In one embodiment, the gNB 170 provides the last-used beam parameter information (e.g., and a RAN ID) to the AMF 190. See block 625. This could be all the information in block 610, or some subset of the information, e.g., perhaps enough to that a gNB 170 can determine the last-used beam(s) by the UE 110 and the gNB 170 would“fill in” any missing information with stored information for the beam(s). The RAN ID is an ID used to uniquely determine this RAN node from other RAN nodes. This can be sent in block 625, or it may be possible for the AMF 190 to determine this via another technique (e.g., perhaps a network address).

[00143] In block 630, the gNB 170 receives beam parameter information (e.g., and a corresponding RAN ID) provided by the AMF and performs paging message transmission using the beam parameter information provided by the AMF, in response to the gNB considering the beam parameter information valid. For instance, the beam parameter information from another eNB might not be valid in a new eNB until after UE mobility (e.g., handover). As an example, the AMF may store beam information for gNB2, but until the UE handovers to gNB2, this information is not valid, as the information is gNB-specific. So beam information of gNBl cannot be used in gNB2. This would be applicable if the UE is in the coverage area of multiple gNBs but is only listening to one gNB at a time. Note that the beam parameter information may include all or some subset of the information in block 610.

[00144] In one embodiment, in response to there being more than one UE to be paged on a paging occasion with each of the UEs having a different last known beam, the gNB 170 sends different PDCCH on each of the beams with different RNTI (beam specific RNTI) instead of using a common RNTI. See block 635.

[00145] In another embodiment, the gNB reserves multiple P-RNTI with one P- RNTI assigned for each of the beams. See block 640. The corresponding P-RNTI would be used for each beam.

[00146] In a further exemplary embodiment, the gNB 170 receives indication from the AMF 190 that paging is re-transmission and the paging needs to be sent over multiple beams, and sends multiple DCI in different beams (e.g., one DCI in each beam) but with the same PDSCH allocation. See block 645. The multiple beams may be multiple preferred beams or all beams. As is known, DCI contains the scheduling information for the paging message. DCI is sent on the control channel PDCCH and the paging message is sent on the data channel PDSCH. The DCI can also indicate the beams to be used for receiving the PDSCH, as in block 650. This would allow the PDSCH (paging message) to be sent using a different beam than the PDCCH (DCI). This might be beneficial, e.g., if the DCI is narrow-beam but PDSCH is wider-beam to cover more cell area.

[00147] Turning to FIG. 7, this figure is a logic flow diagram performed by an AMF 190 for paging using beam parameters for beam-based operation, in accordance with exemplary embodiments. FIG. 7 illustrates the operation of exemplary methods, a result of execution of computer program instructions embodied on a computer readable memory, functions performed by logic implemented in hardware, and/or interconnected means for performing functions in accordance with exemplary embodiments. The AMF 190 performs the blocks in FIG. 7, e.g., under control of the paging module 145.

[00148] In one embodiment, in block 710, the AMF 190 receives and stores all the received beam parameter information together with UE identification and gNB identification information, e.g., as part of UE context in AMF (clause 5.2.2.2.2 for 3GPP TS 23.502 V16.1.1 (2019-06)). In more detail, the AMF stores all the beam parameter information that the AMF receives from the RAN node, associated with the RAN ID. This stored information may be considered to be a block of RAN-related information that the AMF stores on behalf of RAN node for possible later use. The exact content of this information can be implementation-specific or defined through other techniques, such as a standard.

[00149] In one embodiment, the AMF 190 provides the stored beam parameter information to the gNB during a paging procedure, as illustrated by block 720. There are multiple ways to implement block 720. One possible implementation is illustrated by block 740, where the AMF 190 sends the beam parameter and associated RAN ID with the expectation that RAN node ignores beam parameters detected by another RAN node. This might involve sending the beam parameter to multiple gNBs (as RAN nodes), e.g., to which a UE can register or may have registered in the past. While it is expected that all but the gNB with the correct RAN ID will ignore the beam parameter, it is possible that a gNB with a different RAN node will not. Consider a large warehouse with known dimensions and multiple similar gNBs (e.g., mounted on the ceiling) to cover the floor of the warehouse. Assume each gNB has multiple beams to cover smaller rectangles in the warehouse, where each gNB covers the extent of a“y” direction and will handover UEs traveling in an“x” direction (x, y perpendicular). If a UE is moving in a line, in the“x” direction, the same beam configuration could be used for multiple gNBs along that line. If a UE is handed over from one to another gNB, while traveling in the x direction, and then is paged, the other gNB might be able to use the beam parameter information meant for the original gNB from which the UE has been handed over. Different RAN nodes could also be aware of each others’ beam forms, and consequently any beam form used by any RAN node could determine the location with sufficient accuracy for another RAN node to determine its own corresponding beam form for the location. As an alternative, as illustrated by block 750, the AMF 190 could send a beam parameter only to the RAN node that matches with the RAN ID. [00150] In another embodiment, in block 730, the AMF 190 will indicate to the gNB that the paging is a re-transmission and the paging needs to be sent over multiple beams. In this case, the gNB 170 sends multiple DCI in different beams but with the same PDSCH allocation. In this embodiment, the DCI can also indicate the beams to be used for receiving the PDSCH. See corresponding blocks 645 and 650 of FIG. 6.

[00151] Without in any way limiting the scope, interpretation, or application of the claims appearing below, a technical effect of one or more of the example embodiments disclosed herein is a significant reduction the overhead associated with paging in beam-based operation in certain cases (e.g., stationary or low-mobility UE). For instance, if a cell is using 16 beams and only one UE is being paged, the gNB 170 transmits the paging message in only one subframe based on the stored preferred beam instead of in 16 subframes. Additionally, the RAN node can use this beam parameter information to page the UE more efficiently by omitting paging on all beams and just attempting the last-used beam or beams (based on the stored beam parameter information). This yields capacity saving in the unused beams.

[00152] As used in this application, the term“circuitry” may refer to one or more or all of the following:

[00153] (a) hardware-only circuit implementations (such as implementations in only analog and/or digital circuitry) and

[00154] (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 mobile phone or server, to perform various functions) and

[00155] (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.”

[00156] 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.

[00157] Embodiments herein may be implemented in software (executed by one or more processors), hardware (e.g., an application specific integrated circuit), or a combination of software and hardware. In an example embodiment, the software (e.g., application logic, an instruction set) is maintained on any one of various conventional computer-readable media. In the context of this document, a“computer-readable medium” may be any media or means that can contain, store, communicate, propagate or transport the instructions for use by or in connection with an instruction execution system, apparatus, or device, such as a computer, with one example of a computer described and depicted, e.g., in FIG. 1. A computer-readable medium may comprise a computer-readable storage medium (e.g., memories 125, 155, 171 or other device) that may be any media or means that can contain, store, and/or transport the instructions for use by or in connection with an instruction execution system, apparatus, or device, such as a computer. A computer-readable storage medium does not comprise

propagating signals.

[00158] If desired, the different functions discussed herein may be performed in a different order and/or concurrently with each other. Furthermore, if desired, one or more of the above-described functions may be optional or may be combined.

[00159] Although various aspects of the invention are set out in the independent claims, other aspects of the invention comprise other combinations of features from the described embodiments and/or the dependent claims with the features of the independent claims, and not solely the combinations explicitly set out in the claims.

[00160] It is also noted herein that while the above describes example

embodiments of the invention, these descriptions should not be viewed in a limiting sense.

Rather, there are several variations and modifications which may be made without departing from the scope of the present invention as defined in the appended claims.