Relay UE-Assisted RAN Notification Area Update Procedure

Abstract

The present disclosure relates to a relay user equipment (UE) assisting one or more remote UEs in performing a radio access network notification area (RNA) update procedure in a cellular communication system. The relay UE establishes a first relay connection with a first remote device. The first relay connection relays communication between the first remote device and the network. The relay UE transmits a first message initiating the RNA update procedure for the first remote device to the network, receives an acknowledgement message including updated connection information of the first remote device from the network, and transmits the updated connection information to the first remote device.

Description

Technical Field

[0001] This application relates to wireless communications and, more particularly, to systems, apparatuses, and methods for performing relay UE-assisted radio access network notification area (RNA) updates for one or more remote user equipments (UEs) in an inactive state in a cellular communication system.

[0002] Description of the Related Art

[0003] The use of wireless communication systems is growing rapidly. In recent years, wireless devices such as smart phones and tablet computers have become increasingly sophisticated. In addition to supporting telephone calls, many mobile devices (i.e., user equipment devices or UEs) now also provide access to the Internet, email, text messaging, and navigation using the Global Positioning System (GPS), and are capable of operating sophisticated applications that utilize these functions. Additionally, there are many different wireless communication technologies and wireless communication standards. Some examples of wireless communication standards include GSM, UMTS (e.g., associated with the WCDMA or TD-SCDMA air interfaces), LTE, LTE-Advanced (LTE-A), HSPA, 3GPP2 CDMA2000 (e.g., 1xRTT, 1xEV-DO, HRPD, eHRPD), IEEE 802.11 (WLAN or Wi-Fi), BLUETOOTH TM etc.

[0004] The introduction of an increasing number of features and functions in wireless communication devices has also created a continuing need for improved wireless communication and improved wireless communication devices. Specifically, it is important to ensure the accuracy of signals transmitted and received by user equipment (UE) devices (e.g., via wireless devices such as cellular phones, base stations, and relay stations used in wireless cellular communication). In addition, increasing the functionality of UE devices can place a significant strain on the battery life of the UE devices. Therefore, it is also very important to reduce the power requirements in UE device designs while allowing the UE devices to maintain good transmission and reception capabilities to improve communication.

[0005] To increase coverage and better serve the increasing demands and scope of the intended use of wireless communication, in addition to the above communication standards, there are also wireless communication technologies being developed, including fifth-generation (5G) New Radio (NR) communication. Therefore, there is a need to improve the areas that support such development and design. Summary of the Invention

[0006] Embodiments of apparatuses, systems, and methods for performing a relay UE-assisted RNA update process for one or more remote UEs in an inactive state in a cellular communication system are presented herein.

[0007] In some embodiments, a relay UE establishes a first relay connection with a first remote device. The first relay connection relays communication between the first remote device and the network. The relay UE may additionally establish a second relay connection with a second remote device, where the second connection relays communication between the second remote device and the network.

[0008] In some embodiments, the relay UE transmits a first message initiating a radio access network-based notification area (RNA) update procedure for the first remote device and / or for the second remote device to the network. The relay UE may receive an acknowledgement message from the network, the acknowledgement message including updated connection information for the first remote device and / or the second remote device. The relay UE may transmit the updated connection information to the first remote device and / or the second remote device.

[0009] Note that the techniques described herein may be implemented in and / or used with several different types of devices, including but not limited to base stations, access points, cellular telephones, portable media players, tablet computers, wearable devices, and various other computing devices.

[0010] This summary is intended to provide a brief overview of some of the subject matter described in this document. Accordingly, it should be understood that the above features are merely examples and should not be construed in any way as narrowing the scope or essence of the subject matter described herein. Other features, aspects, and advantages of the subject matter described herein will become apparent from the following detailed description, the drawings, and the claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 An exemplary (and simplified) wireless communication system is shown in accordance with some embodiments;

[0012] Figure 2 An exemplary base station communicating with an exemplary wireless user equipment (UE) device is shown in accordance with some embodiments;

[0013] Figure 3 An exemplary block diagram of a UE is shown in accordance with some embodiments;

[0014] Figure 4 An exemplary block diagram of a base station is shown in accordance with some embodiments;

[0015] Figure 5 is a communication flow diagram showing a method for transitioning from a connected state to an inactive state in a cellular communication system in accordance with some embodiments;

[0016] Figure 6is a communication flowchart showing aspects of an exemplary possible model for the inactive state in a cellular communication system according to some embodiments;

[0017] Figure 7 Shows the user plane protocol stack for layer 2 UE to NW relay according to some embodiments;

[0018] Figure 8 Shows the control plane protocol stack for layer 2 UE to NW relay according to some embodiments;

[0019] Figure 9 Shows the deployment scenario for UE to NW relay according to some embodiments;

[0020] Figure 10 Is a table showing various combinations of radio resource control (RRC) connection states for remote UE and relay UE according to various embodiments;

[0021] Figure 11 Shows the deployment scenario where the remote UE moves into the direct coverage area of the gNB in the UE to NW relay;

[0022] Figure 12 Shows how the UE to NW relay can increase the coverage area of the RNA according to some embodiments;

[0023] Figure 13 Is a communication flowchart showing a method for a relay UE and a remote UE to enter the RRC inactive state and restore the connection of these UEs to the network according to some embodiments;

[0024] Figure 14 Is a communication flowchart showing a method for a relay UE in the RRC connected state to assist a remote UE in an RNA update process according to some embodiments;

[0025] Figure 15 Is a communication flowchart showing a method for a relay UE in the RRC inactive state to assist a remote UE in an RNA update process according to some embodiments;

[0026] Figure 16 Is a communication flowchart showing a method for a relay UE to assist multiple remote UEs in an RNA update process according to some embodiments;

[0027] Figure 17 Is a communication flowchart showing a method for a relay UE in the RRC inactive state to assist multiple remote UEs in an RNA update process according to some embodiments;

[0028] Figure 18is a communication flowchart showing a method for a relay UE in an RRC connected state to assist multiple remote UEs in an RNA update process according to some embodiments; and

[0029] Figure 19 is a flowchart showing a method for a relay UE to assist one or more remote UEs in performing an RNA update process according to some embodiments.

[0030] Although the features described herein are susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and are described in detail herein. However, it should be understood that the drawings and the detailed description thereof are not intended to limit the present disclosure to the specific forms disclosed, but on the contrary, are intended to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the subject matter as defined by the appended claims. Detailed Description

[0031] Acronyms

[0032] Various acronyms are used throughout this disclosure. The definitions of the most prominent acronyms that may appear throughout this disclosure are as follows:

[0033] ● UE: User Equipment

[0034] ● RF: Radio Frequency

[0035] ● BS: Base Station

[0036] ● GSM: Global System for Mobile Communications

[0037] ● UMTS: Universal Mobile Telecommunications System

[0038] ● LTE: Long Term Evolution

[0039] ● NR: New Radio

[0040] ● RAN: Radio Access Network

[0041] ● RNA: RAN Notification Area

[0042] ● TX: Transmission

[0043] ● RX: Reception

[0044] ● LAN: Local Area Network

[0045] ● WLAN: Wireless LAN

[0046] ● AP: Access Point

[0047] ● RAT: Radio Access Technology

[0048] ●IEEE: Institute of Electrical and Electronics Engineers

[0049] ●Wi-Fi: A radio access technology (RAT) for wireless local area networks (WLANs) based on the IEEE 802.11 standard

[0050] Terminology

[0051] The following is a glossary of terms that will appear in this application:

[0052] Memory medium - Any of various types of non-transitory memory devices or storage devices. The term "memory medium" is intended to include installation media such as CD-ROMs, floppy disks, or tape devices; computer system memory or random access memory such as DRAM, DDR RAM, SRAM, EDO RAM, Rambus RAM, etc.; non-volatile memory such as flash memory, magnetic media such as hard disk drives or optical storage devices; registers, or other similar types of memory elements, etc. The memory medium may also include other types of non-transitory memory or combinations thereof. In addition, the memory medium may be located in a first computer system that executes a program, or may be located in a different second computer system that is connected to the first computer system via a network such as the Internet. In the latter instance, the second computer system may provide program instructions to the first computer system for execution. The term "memory medium" may include two or more memory media that may reside at different locations in different computer systems connected, for example, via a network. The memory medium may store program instructions (e.g., embodied as a computer program) executable by one or more processors.

[0053] Carrier medium - The memory medium as described above, and physical transmission media such as buses, networks, and / or other physical transmission media that convey signals such as electrical, electromagnetic, or digital signals.

[0054] Computer system (or computer) - Any of various types of computing or processing systems, including personal computer systems (PCs), mainframe computer systems, workstations, network appliances, Internet appliances, personal digital assistants (PDAs), television systems, grid computing systems, or other devices or combinations of devices. Generally, the term "computer system" may be broadly defined as any device (or combination of devices) that includes at least one processor that executes instructions from a memory medium.

[0055] User equipment (UE) (or "UE device") - Any of various types of computer systems or devices that are mobile or portable and perform wireless communication. Examples of UE devices include mobile phones or smartphones (e.g., iPhone TM , based on Android TMphone), tablet computer (e.g., iPad TM , Samsung Galaxy TM ), portable gaming device (e.g., Nintendo DS TM , PlayStation Portable TM , Gameboy Advance TM , iPhone TM ), wearable device (e.g., smart watch, smart glasses), laptop, PDA, portable Internet device, music player, data storage device, or other handheld devices, etc. Generally, the term "UE" or "UE device" can be broadly defined as including any electronic device, computing device, and / or telecommunications device (or combination of devices) that is convenient for users to transport and capable of wireless communication.

[0056] Wireless device - Any one of various types of computer systems or devices that perform wireless communication. The wireless device can be portable (or mobile), or can be stationary or fixed at a certain location. UE is an example of a wireless device.

[0057] Communication device - Any one of various types of computer systems or devices that perform communication, where the communication can be wired or wireless. The communication device can be portable (or mobile), or can be stationary or fixed at a certain location. A wireless device is an example of a communication device. UE is another example of a communication device.

[0058] Base station (BS) - The term "base station" has the full scope of its ordinary meaning and at least includes a wireless communication station installed at a fixed location and used for communication as part of a wireless telephone system or radio system.

[0059] Processing element (or processor) - Refers to various elements or combinations of elements that can execute functions in a device (such as a user equipment device or a cellular network device). The processing element can include, for example: a processor and associated memory, parts or circuits of individual processor cores, entire processor cores, processor arrays, circuits such as ASIC (Application Specific Integrated Circuit), programmable hardware elements such as Field Programmable Gate Array (FPGA), and any one of various combinations above.

[0060] Wi-Fi - The term "Wi-Fi" has the full scope of its ordinary meaning and includes at least a wireless communication network or RAT that is served by wireless LAN (WLAN) access points and provides connectivity to the Internet through these access points. Most modern Wi-Fi networks (or WLAN networks) are based on the IEEE 802.11 standard and are marketed under the name "Wi-Fi". Wi-Fi (WLAN) networks are different from cellular networks.

[0061] Automatically - means that a computer system (e.g., software executed by a computer system) or a device (e.g., a circuit, a programmable hardware element, an ASIC, etc.) performs the action or operation without the action or operation being directly specified or performed through user input. Thus, the term "automatically" contrasts with a user manually performing or specifying an operation, where the user provides input to directly perform the operation. An automatic process can be initiated by input provided by the user, but the subsequent actions that are "automatically" performed are not specified by the user, i.e., are not "manually" performed, where the user specifies each action to be performed. For example, a user filling out a spreadsheet by selecting each field and providing input to specify information (e.g., by typing information, selecting checkboxes, radio selections, etc.) is manually filling out the spreadsheet, even though the computer system must update the spreadsheet in response to the user's actions. The spreadsheet can be filled out automatically by a computer system, where the computer system (e.g., software executed on the computer system) analyzes the fields of the spreadsheet and fills out the spreadsheet without any user input specifying the answers to the fields. As indicated above, the user can initiate the automatic filling out of the spreadsheet but does not participate in the actual filling out of the spreadsheet (e.g., the user does not manually specify the answers to the fields but they are completed automatically). This specification provides various examples of operations that are automatically performed in response to actions taken by the user.

[0062] Configured to - Various components can be described as "configured to" perform one or more tasks. In such an environment, "configured to" is a broad statement generally meaning "having" the "structure" to perform one or more tasks during operation. Thus, even when the component is not currently performing a task, the component can be configured to perform the task (e.g., a set of electrical conductors can be configured to electrically connect a module to another module, even when the two modules are not connected). In some contexts, "configured to" can be a broad statement generally meaning "having" the "circuitry" to perform one or more tasks during operation. Thus, even when the component is not currently powered on, the component can be configured to perform the task. Generally, the circuitry that forms the structure corresponding to "configured to" can include hardware circuitry.

[0063] For ease of description, various components may be described as performing one or more tasks. Such descriptions should be interpreted as including the phrase "configured to". A component configured to perform one or more tasks is expressly intended not to invoke the interpretation of 35 U.S.C. § 112(f) with respect to that component.

[0064] Figure 1 and Figure 2 - Exemplary communication system

[0065] Figure 1 FIG. shows an exemplary (and simplified) wireless communication system in which various aspects of the present disclosure may be implemented, according to some embodiments. Note that Figure 1 the system shown is only one example of a possible system, and the embodiment may be implemented in any of a variety of systems as needed.

[0066] As shown, the exemplary wireless communication system includes a base station 102 that communicates with one or more (e.g., any number) user equipments 106A, 106B, etc. up to 106N via a transmission medium. Each user equipment may be referred to herein as a "user equipment" (UE) or UE device. Thus, user equipment 106 is referred to as a UE or UE device.

[0067] The base station 102 may be a transceiver base station (BTS) or cell site and may include hardware and / or software for implementing wireless communication with UEs 106A - 106N. If the base station 102 is implemented in the context of LTE, it may be referred to as an "eNodeB" or "eNB". If the base station 102 is implemented in the context of 5G NR, it may alternatively be referred to as a "gNodeB" or "gNB". The base station 102 may also be equipped to communicate with a network 100 (e.g., the core network of a cellular service provider, a telecommunications network such as the Public Switched Telephone Network (PSTN), and / or the Internet, and various possible networks). Thus, the base station 102 may facilitate communication between user equipments and / or between user equipments and the network 100. The communication area (or coverage area) of the base station may be referred to as a "cell". Also as used herein, with respect to a UE, the base station may be considered to represent the network, sometimes taking into account the uplink and downlink communications of the UE. Thus, a UE that communicates with one or more base stations in the network may also be understood to communicate with the network.

[0068] The base station 102 and the user equipment may be configured to communicate via a transmission medium using any one of various radio access technologies (RATs), which are also referred to as wireless communication technologies or telecommunication standards, such as GSM, UMTS (WCDMA), LTE, advanced LTE (LTE-A), LAA / LTE-U, 5G NR, 3GPP2, CDMA2000 (e.g., 1xRTT, 1xEV-DO, HRPD, eHRPD), Wi-Fi, etc.

[0069] Base station 102 and other similar base stations operating according to the same or different cellular communication standards may thus provide a network of one or more cells that may provide continuous or near-continuous overlapping services to UE 106 and similar devices over a geographical area via one or more cellular communication standards.

[0070] Note that UE 106 is capable of communicating using multiple wireless communication standards. For example, UE 106 may be configured to communicate using either or both of the 3GPP cellular communication standards or the 3GPP2 cellular communication standards. UE 106 may also be configured or alternatively configured to communicate using WLAN, BLUETOOTH TM , one or more global navigation satellite systems (GNSS, e.g., GPS or GLONASS), one and / or more mobile television broadcast standards (e.g., ATSC-M / H), etc. Other combinations of wireless communication standards (including more than two wireless communication standards) are also possible.

[0071] In some embodiments, UE 106 may be configured to perform data communication when operating in the RRC inactive state at least according to the various methods described herein.

[0072] Figure 2An exemplary user equipment 106 (e.g., one of devices 106A to 106N) communicating with a base station 102 according to some embodiments is shown. The UE 106 can be a device with wireless network connectivity, such as a mobile phone, a handheld device, a wearable device, a computer, or a tablet, or substantially any type of wireless device. The UE 106 can include a processor (processing element) configured to execute program instructions stored in a memory. The UE 106 can execute any of the method embodiments described in the present invention by executing such stored instructions. Alternatively or additionally, the UE 106 can include programmable hardware elements, such as FPGAs (field programmable gate arrays), integrated circuits, and / or any of various other possible hardware components configured to execute (e.g., individually or in combination) any one or any part of the method embodiments described herein. The UE 106 can be configured to communicate using any one of a plurality of wireless communication protocols. For example, the UE 106 can be configured to communicate using two or more of CDMA2000, LTE, LTE-A, 5GNR, WLAN, or GNSS. Other combinations of wireless communication standards are also possible.

[0073] The UE 106 can include one or more antennas for communicating using one or more wireless communication protocols according to one or more RAT standards. In some embodiments, the UE 106 can share one or more portions of a receive chain and / or a transmit chain among multiple wireless communication standards. The shared radio components can include a single antenna or can include multiple antennas for performing wireless communication (e.g., for MIMO). Generally, the radio components can include any combination of a baseband processor, analog radio frequency (RF) signal processing circuitry (e.g., including filters, mixers, oscillators, amplifiers, etc.), or digital processing circuitry (e.g., for digital modulation and other digital processing). Similarly, the radio components can use the foregoing hardware to implement one or more receive chains and transmit chains.

[0074] In some embodiments, the UE 106 can include separate transmit chains and / or receive chains (e.g., including separate antennas and other radio components) for each wireless communication protocol it is configured to communicate with. As another possibility, the UE 106 can include one or more radio components shared among multiple wireless communication protocols and one or more radio components uniquely used by a single wireless communication protocol. For example, the UE 106 can include shared radio components for communicating using any one of LTE or CDMA2000 1xRTT (or LTE or NR, or LTE or GSM), and radio components for using Wi-Fi and BLUETOOTH TMSeparate radio components for communicating with each of the above. Other configurations are also possible.

[0075] Figure 3 - Block diagram of an exemplary UE device

[0076] Figure 3 FIG. shows a block diagram of an exemplary UE 106 according to some embodiments. As shown, UE 106 may include a system-on-chip (SOC) 300, which may include portions for various purposes. For example, as shown, SOC 300 may include a processor 302 that can execute program instructions for UE 106, and a display circuit 304 that can perform graphics processing and provide a display signal to a display 360. Processor 302 may also be coupled to a memory management unit (MMU) 340, which may be configured to receive addresses from processor 302 and translate those addresses into locations in a memory (e.g., memory 306, read-only memory (ROM) 350, NAND flash memory 310) and / or other circuits or devices, such as display circuit 304, radio components 330, connector I / F 320, and / or display 360. MMU 340 may be configured to perform memory protection and page table translation or setup. In some embodiments, MMU 340 may be included as part of processor 302.

[0077] As shown, SOC 300 may be coupled to various other circuits of UE 106. For example, UE 106 may include various types of memory (e.g., including NAND flash 310), a connector interface 320 (e.g., for coupling to a computer system, docking station, charging station, etc.), a display 360, and a wireless communication circuit 330 (e.g., for LTE, LTE-A, NR, CDMA2000, BLUETOOTH TM , Wi-Fi, GPS, etc.). UE device 106 may include at least one antenna (e.g., 335a), and may include multiple antennas (e.g., shown by antennas 335a and 335b) for performing wireless communication with a base station and / or other devices. Antennas 335a and 335b are shown by way of example, and UE device 106 may include fewer or more antennas. Generally speaking, one or more antennas are collectively referred to as antenna 335. For example, UE device 106 may use antenna 335 via radio circuit 330 to perform wireless communication. As described above, in some embodiments, the UE may be configured to use multiple wireless communication standards for wireless communication.

[0078] As further described hereinbelow, the UE 106 (and / or the base station 102) may include hardware and software components for implementing methods for at least the UE 106 to function as a relay UE between one or more remote UEs and the network and to assist in a RAN-based notification area (RNA) update process for the remote UEs in a cellular communication system. The processor 302 of the UE device 106 may be configured to implement part or all of the methods described herein, for example, by executing program instructions stored on a memory medium (e.g., a non-transitory computer-readable memory medium). In other embodiments, the processor 302 may be configured as a programmable hardware element, such as an FPGA (field-programmable gate array) or as an ASIC (application-specific integrated circuit). Further, as Figure 3 shown, the processor 302 may be coupled to and / or interoperate with other components to perform an RNA update process in a cellular communication system according to the various embodiments disclosed herein. The processor 302 may also implement various other applications and / or end-user applications running on the UE 106.

[0079] In some embodiments, the radio component 330 may include separate controllers dedicated to controlling communications for various respective RAT standards. For example, as Figure 3 shown, the radio component 330 may include a Wi-Fi controller 332, a cellular controller (e.g., an NR controller) 334, and a BLUETOOTH TM controller 336, and in at least some embodiments, one or more or all of these controllers may be implemented as respective integrated circuits (simply referred to as ICs or chips) that communicate with each other and with the SOC 300 (more specifically with one or more processors 302). For example, the Wi-Fi controller 332 may communicate with the cellular controller 334 via a cell-ISM link or a WCI interface, and / or the BLUETOOTH TM controller 336 may communicate with the cellular controller 334 via a cell-ISM link or the like. Although three separate controllers are shown within the radio component 330, other embodiments may have fewer or more similar controllers for the various different RATs that may be implemented in the UE device 106.

[0080] Figure 4 - Block diagram of an exemplary base station

[0081] Figure 4 A block diagram of an exemplary base station 102 according to some embodiments is shown. Note that Figure 4The base station shown is only one example of a possible base station. As shown, base station 102 may include a processor 404 that can execute program instructions for base station 102. Processor 404 may also be coupled to a memory management unit (MMU) 440 or other circuits or devices, which may be configured to receive addresses from processor 404 and translate these addresses into locations in a memory (e.g., memory 460 and read-only memory (ROM) 450).

[0082] Base station 102 may include at least one network port 470. Network port 470 may be configured to couple to a telephone network and provide access to a plurality of devices such as UE device 106 to the telephone network as described above in Figure 1 and Figure 2 . Network port 470 (or an additional network port) may also be configured or alternatively configured to couple to a cellular network, such as the core network of a cellular service provider. The core network may provide mobility-related services and / or other services to a plurality of devices such as UE device 106. In some cases, network port 470 may be coupled to the telephone network via the core network, and / or the core network may provide the telephone network (e.g., in other UE devices served by the cellular service provider).

[0083] Base station 102 may include at least one antenna 434 and possibly a plurality of antennas. One or more antennas 434 may be configured to operate as a wireless transceiver and may be further configured to communicate with UE device 106 via radio component 430. Antenna 434 communicates with radio component 430 via communication link 432. Communication link 432 may be a receive link, a transmit link, or both. Radio component 430 may be designed to communicate via various radio telecommunications standards, which include but are not limited to NR, LTE, LTE-A, WCDMA, CDMA2000, etc. Processor 404 of base station 102 may be configured to implement and / or support the implementation of part or all of the methods described herein, for example by executing program instructions stored on a memory medium (e.g., a non-transitory computer-readable memory medium). Alternatively, processor 404 may be configured as a programmable hardware element such as an FPGA (field programmable gate array), or as an ASIC (application specific integrated circuit), or a combination thereof. In the case of certain RATs (e.g., Wi-Fi), base station 102 may be designed as an access point (AP), in which case network port 470 may be implemented to provide access to a wide area network and / or one or more local area networks, e.g., it may include at least one Ethernet port, and radio component 430 may be designed to communicate according to the Wi-Fi standard. Base station 102 may operate according to the various methods disclosed herein for enabling a wireless device to perform data communication in a cellular communication system while in an inactive state.

[0084] 5G NR - RRC Inactive State

[0085] Multiple cellular communication technologies include using a Radio Resource Control (RRC) protocol (e.g., which may facilitate connection establishment and release, radio bearer establishment, re - configuration and release) and / or various other possible signaling functions that support the air interface between a wireless device and a cellular base station.

[0086] A wireless device can generally operate in one of a number of possible states with respect to RRC. For example, in LTE, a wireless device can operate in an RRC connected state (e.g., where the wireless device can perform continuous data transmission, and where handovers between cells are managed by the network and the access stratum context information is reserved for the wireless device), or can operate in an RRC idle state (e.g., where the wireless device can operate in a more battery - efficient state when not performing continuous data transmission, where the wireless device can handle its cell reselection activities, and where the network may not reserve the access stratum context information for the wireless device).

[0087] In addition to the RRC connected state and the RRC idle state, at least according to some embodiments, one or more other types of RRC states for wireless devices may also be supported. For example, for 5G NR, an RRC inactive state may be supported, in which a wireless device may be able to operate in a battery - efficient state while the network also retains at least some access stratum (AS) context information. At least according to some aspects, this state may be based on the mobility of the wireless device, e.g., such that the wireless device can move within a Radio Access Network Notification Area (RNA) without notifying the Radio Access Network (RAN). When in this state, the wireless device can perform cell reselection and system information acquisition for itself. Meanwhile, the last - serving base station (e.g., gNB) can maintain the wireless device context and the NR connection to the 5G Core Network (CN) associated with the wireless device, e.g., to facilitate an easier transition back to the RRC connected state. When paging a wireless device in the RRC inactive state, the RAN can use RNA - specific parameters, e.g., including UE - specific DRX and UE identity index values (e.g., I - RNTI).

[0088] According to various embodiments, e.g., when a wireless device moves out of its currently configured RNA to a different RNA, a wireless device operating in this RRC inactive state can perform RNA updates periodically (e.g., based on a configured periodic RNA update timer) and / or in an event - based manner. Exemplary embodiments herein describe methods and devices for a relay UE to assist one or more remote UEs in performing an RNA update process.

[0089] In at least some cases, using the RRC Inactive state can help reduce the network signaling overhead for a wireless device connection. For example, for a wireless device with infrequent data transmissions, using this RRC Inactive state can reduce the amount of mobility-related signaling (e.g., for handovers) required compared to using the RRC Connected state. For example, because the wireless device may be able to manage its own cell reselection process when moving between cells. For such wireless devices, using the RRC Inactive state can also reduce the amount of connection establishment-related signaling required compared to using the RRC Idle state. For example, because the network can retain at least some context information for the wireless device. This can directly reduce the signaling latency associated with transitioning to the RRC Connected state.

[0090] As another potential benefit, for example, compared to operating in the RRC Idle state, this state can reduce the control plane latency of the wireless device. For example, for the RRC Inactive state relative to the RRC Idle state, it is possible to shorten the access stratum connection establishment period and / or the non-access stratum connection establishment period. Therefore, the time from the battery active state to the start of continuous data transmission can be reduced.

[0091] Additionally, for example, compared to operating in the RRC Connected state, this state can improve the power saving ability of the wireless device. For example, compared to when in the RRC Inactive state, when in the RRC Connected state, services and / or neighbor cell measurements may be required more frequently. For example, at least in line with the connected state discontinuous reception (C-DRX) cycle of the wireless device.

[0092] Figure 5 is a communication flow diagram showing a method for a UE to establish an RRC connection and transition to the RRC Inactive state. At 502, the wireless device and the cellular base station can establish an RRC connection. For example, the wireless device can attach to a cell provided by the cellular base station. At least according to some embodiments, establishing the RRC connection can include configuring various parameters for communication between the wireless device and the cellular base station, establishing context information for the wireless device, and / or any of various other possible features. For example, it involves establishing an air interface for the wireless device to perform cellular communication with the cellular network associated with the cellular base station. After establishing the RRC connection, the wireless device can operate in the RRC Connected state. At least in some embodiments, when in the RRC Connected state, the wireless device can undergo a handover from one serving cell (e.g., provided by the cellular base station) to another serving cell (e.g., provided by a different cellular base station).

[0093] In 504, a wireless device may transition from the RRC connected state to the RRC inactive state. The transition from the RRC connected state to the RRC inactive state may include the wireless device receiving an indication to release or deactivate the RRC connection and / or otherwise determining that a trigger for releasing or deactivating the RRC connection has occurred. At least in part based on the indication (and / or other trigger), the wireless device may transition from the RRC connected state to the RRC inactive state. The indication may be received from a cellular base station (e.g., the base station with which the RRC connection was established, or possibly a different cellular base station if handover has occurred one or more times). When in the RRC inactive state, if the network has data based on the association of the wireless device with the current RNA, the wireless device may be paged via the cell of the current RNA.

[0094] The RRC inactive state is an operating mode supported in 5G NR, which can reduce the signaling overhead and power consumption for the UE compared to the RRC connected state, while improving the UE access latency compared to the RRC idle state. For example, for UEs with infrequent data transmissions, operating in the RRC inactive state can reduce mobility-related signaling (e.g., handovers can be avoided) compared to operating in the RRC connected state, and operating in the RRC inactive state can reduce connection setup-related signaling compared to operating in the RRC idle state. The time to transition from the battery active state to the start of continuous data transmission (e.g., control plane latency) can also be reduced. For example, compared to a UE in the RRC active state, a UE in the RRC inactive state can reduce the control plane latency caused by the access stratum connection establishment and non-access stratum connection establishment time periods. The power consumption can be reduced compared to operating in the RRC connected state, e.g., because measurements may be performed less frequently (e.g., in the RRC connected state, it may be the case that measurements must meet the connection state measurement requirements based on the connection state discontinuous reception (C-DRX) cycle).

[0095] At least according to some embodiments, the transition between the RRC inactive state and the RRC connected state may be performed without affecting the core network. The UE and the RAN (e.g., the UE's previous serving gNB) may store the UE access stratum context when the UE is in the RRC inactive state. Mobility in the RRC inactive state may be handled in a UE-centric manner (e.g., similar to the RRC idle state), where cell reselection is being performed by the UE. Such mobility activities and the exact RRC state of the UE may be hidden from the core network. State changes from the RRC inactive state to the RRC connected state or vice versa, and changes from the RRC inactive state to the RRC idle state may be possible. Note that at least in some cases, the transition from the RRC idle state to the RRC inactive state may not be supported.

[0096] Similar to the core network tracking area concept used to support UE mobility in the idle state, the inactivity state can use a RAN notification area (RNA) that can be configured by the gNB on a per-UE basis. Via RAN-initiated paging (e.g., according to the UE-specific DRX cycle), using the RAN-configured UE ID (I-RNTI), e.g., by all gNBs within the RNA, the UE is reachable within its configured RNA. RNA updates can be triggered periodically (e.g., based on a configured periodic RNA update timer) and when moving outside the configured RNA.

[0097] Figure 6 is a communication flowchart showing a possible signaling procedure for performing an RNA update procedure when in the RRC inactive state. As shown, at 610, the UE 602 may provide a RRCConnectionResumeRequest (e.g., with an indication for performing an RNA update) to its current serving gNB 604. At 612, the current serving gNB 604 may provide a retrieve UE context request to the previous serving gNB 606. At 614, the previous serving gNB 606 may provide a retrieve UE context response to the current serving gNB 604. At 616, the current serving gNB 604 may provide a RRCConnectionRelease / Resume message to the UE 602. At 618, the current serving gNB 604 may also provide a data forwarding address indication to the previous serving gNB 606. At 620, the current serving gNB 604 may also provide a path switch request to the AMF 608 (e.g., the AMF serving the RNA). At 622, the AMF 608 may provide a path switch request confirmation to the current serving gNB 604. At 624, the current serving gNB 604 may provide a UE context release message to the previous serving gNB 606.

[0098] UE to NW Relay

[0099] In some embodiments, a UE such as UE 106A - 106N may act as a relay UE to relay communications between a remote UE and a network (NW). As an example, the relay UE may be a smart phone, and the remote UE may be an accessory or a wearable device that utilizes the relay connection with the smart phone to access the cellular network. Alternatively, in various embodiments, each of the remote device and the relay device may be any one of various types of UE devices. The term "relay UE" herein is not intended to refer to a specific type of UE device, but rather a functional description of the relay UE acting as a repeater between the remote UE and the NW. Similarly, "remote UE" is a functional term used to refer to a UE device that is communicating with the NW using a sidelink connection with the relay UE.

[0100] Generally, relaying is performed above the radio link control (RLC) sublayer of the protocol architecture for both the user plane and the control plane. For example, Figure 7 and Figure 8 respectively illustrate the user plane protocol stack and the control plane protocol stack for layer 2 UE - to - NW relaying. As shown, Uu PDCP and RRC terminate between the evolved ProSe remote UE and the gNB, while RLC, MAC, and PHY terminate in each link. Figure 9 Illustrates a deployment scenario where the relay UE is within the communicable range of the gNB and acts as a repeater for communications between a remote UE (which is not within the communicable range of the gNB but is within the communicable range of the relay UE) and the gNB.

[0101] In some embodiments, UE - to - NW relaying may be implemented in a 5G NR communication environment where one or both of the remote UE and the relay UE operate in the RRC inactive state. The embodiments herein present communication enhancements to improve the effectiveness and / or efficiency of UE - to - NW relaying communications in these environments. For example, it may be desirable to quickly resume the RRC connection for a remote UE operating in the RRC inactive state.

[0102] Figure 10It is a table summarizing various scenarios in which one or both of the remote UE and the relay UE are operating in the RRC inactive state. For example, the remote UE may operate in the RRC inactive state while the relay UE operates in the RRC connected state, RRC inactive state, or RRC idle state. When the remote UE is in the RRC inactive state and the relay UE is in the RRC connected state or inactive state, the embodiments herein present a method for achieving fast RRC connection recovery for the remote UE, such as by utilizing the relay UE to assist in the RNA update process for the remote UE. Conversely, when the remote UE is in the RRC inactive state and the relay UE is in the RRC idle state, it may not be desirable to implement the methods described herein because the latency for restoring the end-to-end connection with the remote UE may be large due to the latency from the idle relay UE involved in the communication. In an exemplary embodiment, once the PC5 link between the remote UE and the relay UE has been established, a method for the relay UE to assist the remote UE in RNA update can be executed. For example, if the remote UE is not connected to the relay UE, the gNB may not be reachable to implement the embodiments described herein.

[0103] In 5G NR, a UE in the RRC inactive state retains its UE inactive access stratum (AS) context. Generally, the UE AS context can be divided into an upper layer and a lower layer. The upper layer includes bearer configurations such as signaling radio bearer 1 (SRB1), signaling radio bearer 2 (SRB2), data radio bearer 1 (DRB1), etc., and associated security configurations. The lower layer includes master cell group (MCG) configurations (including MCG SCell) and multi-RAT dual connectivity (MR-DC) related configurations (including secondary cell group (SCG) related information). When the relay UE restores its RRC connection (i.e., when the relay UE transitions from RRC inactive to RRC connected), it may be desirable for the relay UE to quickly resume its forwarding relay function. To address these and other issues, in some embodiments, additional relay information may be added to the UE inactive AS context stored by both the relay UE and the NW. For example, the UE inactive AS context may store the association between the relay UE and one or more remote UEs to which the relay UE is providing relay. Additionally or alternatively, the bearer mapping in the adaptation layer may be stored in the UE inactive AS context, which specifies which end-to-end Uu bearer (in the PDCP layer) is mapped to the Uu bearer between the relay UE and the gNB.

[0104] Figure 11A deployment scenario is shown in which a relay UE is connected to a first gNB (gNB1) and a first remote UE and a second remote UE (remote UE1 and remote UE2). The remote UE2 can be reached via the relay UE via RAN paging for the RAN notification area. If the remote UE 2 moves within the range of a second gNB (gNB2), the remote UE2 can continue to directly receive RAN paging for the RAN notification area from gNB2.

[0105] A remote UE operating in RRC idle or inactive mode can trigger a Tracking Area Update (TAU) and an RNA update, which is similar to a UE directly connected to the network. For example, a remote UE in the RRC inactive state can perform a RAN paging process, an RRC resume process, and an RNA update process. If the remote UE is not connected to the relay UE, the remote UE may need to first select / connect to the relay UE to perform these processes. The TAU process is in the non-access stratum (NAS) layer, where the role of "L2 relay" may be invisible. For example, the L2 relay may not be known to the AMF and may be transparent in the NAS layer.

[0106] In contrast to the NAS, the use of the L2 relay can be known to the gNB and is not transparent in the RRC layer. The RNA can be used for RAN paging. If a gNB belongs to an RNA, all sidelink (SL) relays pre-empted in that gNB can also be responsible for RAN paging via the relay UE to the remote UEs connected to that relay UE.

[0107] Figure 12 It shows how a relay UE can be used to extend the coverage area of an RNA by utilizing the communicable range of the relay UE along the perimeter of the RNA. In some embodiments, the relay UE can be used to assist a remote UE in triggering and / or performing an RNA update process as part of an RRC resume process to transition from RRC inactive to RRC connected. In some embodiments, if the remote UE and the relay UE have an active PC5-RRC connection, the T380 timer expires, and the remote UE detects that the remote UE has moved out of the configured RN, an RNA update process can be triggered, as described in more detail below. Additionally or alternatively, the RRC resume process can be triggered by the upper layer for other reasons.

[0108] When a remote UE is connected to a gNB via a relay UE, the RNA is typically set to be the same as that used for the relay UE, and t380 can be allocated to the remote UE for triggering the RNA update procedure. The remote UE can utilize the sidelink (SL) connection with the relay UE during a mobility scenario to determine the behavior of the remote UE regarding the RNA update procedure. For example, if the relay UE moves away from the remote UE (i.e., out of the range of the remote UE) and the remote UE does not find a new relay UE, the remote UE will be out-of-coverage (OOC) and may not be able to update the RNA of the remote UE. Thus, the NW can release the remote UE to the RRC idle state after the T380 timer expires. Alternatively, when the remote UE loses its connection with the first relay UE and discovers a new relay UE, the remote UE can perform communication to determine whether the new relay UE belongs to the same RNA as the first relay UE. If the new relay UE is in the same RNA and the T380 timer of the remote UE has not expired, there may be no need to perform the RNA update procedure. As another example, in a group mobility scenario (i.e., when the relay UE and the remote UE move simultaneously, such as in a case where both the relay UE and the remote UE are carried by a single user or vehicle), the relay UE can notify the remote UE when the relay UE experiences an RNA change, so that the remote UE can trigger an RNA update.

[0109] In some embodiments, a method can be used by a remote UE to obtain RNA information from a relay UE. As a first option, the relay UE can broadcast the System Information Block 1 (SIB1) that the relay UE received from the gNB, and the SIB1 indicates the RNA to which the relay UE is connected. The remote UE can consider the RNA broadcast by the SIB1 when deciding which of two or more available relay UEs to use for relay communication (e.g., the remote UE can preferentially select a relay UE that is connected to the same or a different RNA as the remote UE). As a second option, the relay UE may not broadcast the RNA information, but can directly transmit the RNA information to the remote UE after establishing a relay connection with the remote UE. In some embodiments, when the remote UE needs to perform an RNA update, the remote UE can first check whether the remote UE is connected to a repeater.

[0110] Figure 13is a communication flow diagram showing a method for relaying a UE 1206 and a remote UE 1202 into the RRC Inactive state and restoring the connection of these UEs to the gNB 1208 according to some embodiments. As shown, at 1210, a relay connection is established and the relay UE is used as a repeater for forwarding uplink and downlink communications to transfer end-to-end traffic between the remote UE and the gNB. At 1212, the gNB determines that the remote UE does not yet have any traffic activity within a pre-determined period of time and determines to suspend the RRC connection of the remote UE. To achieve this, at 1214, the gNB transmits an RRCRelease message to the remote UE via the relay UE. Upon receiving the RRCRelease message, at 1216, the remote UE stores the access stratum (AS) inactive context of the remote UE and enters the RRC Inactive state. In addition, at 1218, the gNB transmits a second RRCRelease message to the relay UE to cause the relay UE to suspend the relay connection and enter the RRC Inactive state. At 1220, the relay UE stores the configuration information related to the relay connection as part of the UE inactive access stratum (AS) context. In some embodiments, the configuration information includes the identity of the remote UE and the bearer mapping as part of the AS inactive context. For example, the configuration information may specify a bearer mapping configuration in the adaptation layer, where the bearer mapping configuration specifies the end-to-end Uu bearer in the Packet Data Convergence Protocol (PDCP) layer to be mapped to the Uu bearer operating between the relay UE and the network. At 1222, the gNB stores the relay UE / remote UE association and the bearer mapping as part of the AS inactive context of the relay UE.

[0111] At 1224, the end-to-end Uu service is resumed by the remote UE, and the remote UE transmits the service to the relay UE to resume the relay connection and forward the service to the gNB. For example, those services can be new end-to-end Uu RRC messages for allowing the UE to resume the RRC_CONNECTED state, or RNA (RAN notification area) update messages, or any other control plane or user plane services generated by the AS (access stratum) layer or upper layer of the remote UE. At 1226, since the relay UE is currently in the RRC inactive state, the relay UE buffers the end-to-end service received from the remote UE. At 1228, the relay UE exchanges RRC resume signaling with the gNB to re-enter the RRC connected state and resume the suspended RRC connection between the relay UE and the gNB. When resuming the relay connection, the relay UE can restore the configuration information of the UE inactive AS context. For example, at 1230, the bearer mapping is restored as part of the UE AS inactive context, and the relay UE enters the RRC connected state. At 1232, the gNB also restores the bearer mapping as part of the UE AS inactive context. Finally, at 1234, the relay UE forwards the end-to-end service received from the remote UE to the gNB.

[0112] Figure 14 is a communication flowchart showing a method for a relay UE 704 to assist a remote UE 702 in performing an RNA update process with a gNB 706 when the relay UE is in the RRC connected mode. As shown, at 708, the gNB transmits an RRCRelease message to the remote UE, and then the remote UE enters the RRC inactive state and starts the T380 timer. Note that the RRCRelease message is transmitted directly to the remote UE without being relayed by the relay UE. Subsequently, the remote UE enters OOC and searches for the relay UE to reconnect to the network. The remote UE and the relay UE perform relay discovery 710, PC5 link establishment 712, and at step 714 the remote UE transmits a system information (SI) request to the relay UE, and at step 716 the relay UE responds with a relay SI response including RNA information. After establishing a relay connection between the remote UE and the relay UE, the remote UE updates its RNA with the information received from the relay UE. If the RNA of the relay UE is different from the previous RNA of the remote UE, the remote UE can trigger an RNA update. At step 720, the remote UE transmits an RRCResumeRequest message to the gNB via the relay UE. In response, at step 726, the gNB updates the remote UE context and transmits an RRCRelease to the remote UE to restart the remote UE's T380 timer.

[0113] Figure 15is a communication flow diagram showing a method for a relay UE 804 to assist a remote UE 802 in performing an RNA update process with a gNB 806 when the relay UE is in the RRC inactive mode. Figure 15 The method shown is in some aspects similar to Figure 14 the method shown. For example, at 808, the gNB transmits an RRCRelease message to the remote UE, whereupon the remote UE enters the RRC inactive state and starts the T380 timer. Note that the RRCRelease message is transmitted directly to the remote UE without being relayed by the relay UE. Subsequently, the remote UE enters OOC and searches for the relay UE to reconnect to the network. The remote UE and the relay UE perform relay discovery 810, PC5 link establishment 812, and at step 814 the remote UE transmits a system information (SI) request to the relay UE, and at step 816 the relay UE responds with a relay SI response including RNA information. After establishing a relay connection between the remote UE and the relay UE, the remote UE aligns the RNA of the remote UE with the RNA of the relay UE. If the RNA of the relay UE is different from the previous RNA of the remote UE, the remote UE may trigger an RNA update. At 820, the remote UE transmits an RRCResumeRequest message to the relay UE. The relay UE buffers the RRCResumeRequest message. At 822, the relay UE and the gNB exchange RRCResume message transfers. After establishing an RRC connection between the relay UE and the gNB, at step 824, the relay UE forwards the buffered RRCResumeRequest message to the gNB. Finally, at step 826, the gNB responds to the remote UE via the relay UE with an RRCRelease message instructing the remote UE to restart the T380 timer of the remote UE.

[0114] In some embodiments, a single relay UE may be connected to multiple remote UEs. If the relay UE is not in the RRC connected state, there may be significant overhead for the relay UE in the case where each remote UE triggers an RNA update at a different time. To address these and other issues, in some embodiments, the relay UE may perform an RNA update on behalf of all remote UEs associated with the relay UE by reporting the IDs of all these remote UEs in a single transmission. As long as the remote UE remains connected to the relay UE (e.g., via PC5-S keep-alive messaging), it may not be necessary to trigger an RNA update when the T380 timer expires.

[0115] In some embodiments, the relay UE may perform an RNA update once as an aggregate update for all connected remote UEs (and itself in the case where the remote UE is in the RRC inactive state). Providing the identifiers of the remote UEs connected to the relay UE to the gNB may allow the gNB to perform additional functions for the remote UEs, such as handover procedures and scheduling and other possibilities. Advantageously, the aggregate update process may significantly reduce signaling overhead.

[0116] In some embodiments, a remote UE may disconnect from its relay UE (e.g., in the case where the remote UE moves out of range), in which case the remote UE may resume its UE-triggered RNA update process based on the T380 timer or RNA area mismatch.

[0117] Figure 16 is a communication flow diagram showing a method for a relay UE 906 to assist multiple remote UEs in an RNA update process. Figure 16 The method shown starts after each of the remote UE1 904 and the remote UE2 902 has established a relay connection with the gNB908 via the relay UE. At 910, user plane data is forwarded to the remote UE 1 and UE 2 via the relay UE. At 912, the gNB assigns the T380 timer to each of the two remote UEs. At 914, the gNB transmits an RRCRelease message to the remote UE1 via the relay UE to cause the remote UE1 to enter the RRC inactive state and start the T380 timer. At 916, the remote UE1 may notify the relay UE of the start of the T380 timer with an RNAUpdateInfo message. At 918, the gNB transmits an RRCRelease message to the remote UE2 via the relay UE to cause the remote UE2 to enter the RRC inactive state and start the T380 timer. At 920, the remote UE2 may notify the relay UE of the start of the T380 timer with an RNAUpdateInfo message.

[0118] The relay UE can determine which of the remote UEs, UE 1 and UE 2, has an earlier expiration time of its respective T380 timer, and can set the earlier expiration timer as the RNA timer to trigger the RNA update procedure for the two remote UEs (and possibly also for the relay UE). Before the T380 timer expires, the relay UE can exchange PC5 keep-alive messaging with remote UE1 924 and remote UE2 922. The relay UE can trigger the RNA update procedure for the two remote UEs based on the expiration of the RNA timer. To this end, the relay UE can transmit a single RelayRNAUpdate message to the gNB at 926, where the RelayRNAUpdate message includes a list of all remote UEs served by the relay UE. If the relay UE is in the RRC inactive state and also wishes to perform the RNA update procedure, the RelayRNAUpdate can also specify the identifier of the relay UE. The gNB can extend the expiration time of all remote UE contexts (and possibly also the relay UE) based on the RelayRNAUpdate message received from the relay UE. At 928, the gNB responds to the relay UE with a RelayRNAUpdateACK message that specifies the subsequent time for performing the next RNA update procedure. At 930 and 932, the relay UE can transmit RNAUpdateTimer messages to remote UE 1 and UE 2 via the PC5 interface, respectively, to notify the remote UEs of the updated timing for the subsequent RNA update procedure.

[0119] Blocking RNA updates for remote UEs

[0120] In some embodiments, rather than having the remote UEs monitor their own T380 timers to initiate the RNA update procedure, the relay UE can directly receive the T380 timer information from the network. For example, when the gNB releases a remote UE to the RRC inactive state via UE-to-NW relay, the gNB can instruct the remote UE to block the RAN update procedure (e.g., by automatically restarting the remote UE's T380 timer). In these embodiments, the timing for performing the RAN update procedure can be determined by the relay UE, which can be done differently depending on whether the relay UE is in the RRC connected state or the inactive state. When the relay UE is in the RRC inactive state, the gNB can configure an RNA update timer for the relay UE when placing the relay UE in the RRC inactive state with an RRCRelease message. When the RNA update timer expires, the relay UE can automatically include a list of its remote UEs in the RRCResumeRequest message from the relay UE to the gNB, thereby triggering the RNA update of the remote UE.

[0121] This process is atFigure 17 It is described in detail in the communication flow chart shown. Figure 17 The method shown starts after each of the remote UEs 1004 and 1002 has established a relay connection with the gNB 1008 via the relay UE 1006. At 1010, user plane data is forwarded to remote UEs 1 and 2 via the relay UE. At 1012, the gNB assigns the T380 timer to each of the two remote UEs. At 1014 and 1016, the gNB transmits RRCRelease messages to remote UE1 and remote UE2 via the relay UE respectively, to cause remote UEs 1 and 2 to enter the RRC inactive state and prevent RNA updates with the automatic restart of the T380 timer.

[0122] The gNB configures the relay UE with the T380 timer for performing the RNA update process, and the T380 timer is earlier than the T380 timer assigned to the remote UEs. At 1018, the gNB transmits an RRCRelease message to the relay UE for the relay UE to start the T380 timer. While the T380 timer of the relay UE is running, the relay UE performs keep-alive message transmission with remote UE 1 (1020) and remote UE 2 (1022) via the PC5 interface.

[0123] When the T380 timer of the relay UE expires, the relay UE triggers an RNA update process for remote UEs 1 and 2 and for the relay UE. To trigger the RNA update process, the relay UE may perform a random access (RACH) process 1024 with the gNB and transmit an RRCResumeRequest message 1026 identifying remote UEs 1 and 2 and the relay UE to the gNB. The gNB may extend the expiration time of the two remote UEs and respond to the relay UE with an RRCRelease message at 1028 to reset the T380 timer.

[0124] Alternatively, when the relay UE is in the RRC connected state, the gNB may configure a periodic registration timer for the relay UE to report the connected remote UEs. In these embodiments, a new Uu RRC message (e.g., RelayRNAUpdate) for notifying the network of the status of one or more remote UEs and / or the relay UE may be introduced. This process is described in detail in Figure 18 It is described in detail in the communication flow chart shown. Figure 18The method shown starts after each of the remote UEs 1104 and 1102 has established a relay connection with the gNB 1108 via the relay UE 1106. At 1110, user plane data is forwarded via the relay UE to remote UEs 1 and 2. At 1112, the gNB assigns the T380 timer to each of the two remote UEs. At 1114 and 1116, the gNB transmits RRCRelease messages to remote UE1 and remote UE2 via the relay UE respectively, to cause remote UEs 1 and 2 to enter the RRC Inactive state and prevent RNA updates with the automatic restart of the T380 timer.

[0125] The gNB configures the relay UE with the T380 timer for performing the RNA update procedure, and this T380 timer is earlier than the T380 timer assigned to the remote UEs. At 1118, the gNB transmits a RelayInfoUpdateConfig message to the relay UE for the relay UE to start the RNA update timer. While the T380 timer of the relay UE is running, the relay UE performs keep-alive messaging with remote UE 1 (1120) and remote UE 2 (1122) via the PC5 interface.

[0126] When the T380 timer of the relay UE expires, the relay UE triggers the RNA update procedure for remote UEs 1 and 2. To trigger the RNA update procedure, the relay UE may transmit a RelayInfoUpdate message 1126 identifying remote UEs 1 and 2 to the gNB. The gNB may extend the expiration time for both remote UEs 1 and 2.

[0127] If the relay UE enters the RRC Idle state and is unable to perform the RNA update procedure on behalf of the remote UEs, the relay UE may notify the connected remote UEs that the UE-triggered RNA update procedures for these remote UEs are no longer blocked.

[0128] Figure 19 - Flowchart for the relay UE-assisted RNA update procedure

[0129] Figure 19 is a flowchart showing a method for a relay UE to assist one or more remote UEs in performing an RNA update procedure according to some embodiments. Figure 19Aspects of the method may be implemented by a wireless device, such as in conjunction with a cellular base station (such as the UE 106 and BS 102 shown and described with respect to the various figures herein), or more generally, in conjunction with any of the computer circuits, systems, devices, elements, or components shown in the above figures as needed. For example, the processor (and / or other hardware) of such a device may be configured such that the device performs any combination of the shown method elements and / or other method elements. The described method steps may be performed by a UE acting as a relay UE between one or more remote UEs and the network.

[0130] Note that although at least some elements of the method are described in a manner related to the use of communication technologies and / or features associated with NR and / or 3GPP specification documents, such a description is not intended to limit the present disclosure, and as needed, Figure 19 aspects of the method may be used in any suitable wireless communication system. In various embodiments, some of the elements of the shown method may be executed simultaneously in a different order than shown, may be replaced by other method elements, or may be omitted. Additional method elements may also be executed as needed. As shown, Figure 19 the method may operate as follows. Figure 19 the method may operate as follows.

[0131] At 1902, a first relay connection with a first remote device is established. The first relay connection relays communication between the first remote device and the network. In some embodiments, the relay UE may additionally establish a second relay connection with a second remote device, where the second connection relays communication between the second remote device and the network. The relay UE may also additionally establish relay connections with one or more third remote UEs.

[0132] In some embodiments, the relay UE receives timer information from the first remote UE and / or the second remote UE. The timer information may include a T380 timer for the respective remote UE, and expiration of the T380 timer may indicate that the respective remote UE is scheduled to perform an RNA update procedure. Alternatively, in some embodiments, the relay UE directly receives timer information (e.g., a T380 timer value) related to the RNA update procedure for the first remote device and / or the second remote device from the network. In these embodiments, the network may have previously configured the first remote device and / or the second remote device to enter the RRC inactive state and blocked RNA updates, while the network directly transmits the timer information to the relay UE for performing the RNA update on behalf of the remote UE. In some embodiments, the relay UE transmits a keep-alive message to the first remote UE and / or the second remote UE via the PC5 interface before the timer expires.

[0133] At 1904, a first message initiating a radio access network-based notification area (RNA) update procedure for a first remote device is transmitted to a network (e.g., gNB). In some embodiments, when the relay UE is in the RRC inactive state, the first message may additionally initiate an RNA update procedure for the relay UE. In some embodiments, the first message is transmitted to the network in response to the expiration of a T380 timer associated with the remote UE. When the relay UE is serving multiple remote UEs, the relay UE may transmit the first message in response to the first expiration of any of the T380 timers of the remote UEs. Regardless of whether the relay UE receives the T380 timer from the remote UE or from the network, the relay UE may monitor the T380 timer to determine when the T380 timer has expired to trigger the transmission of the first message initiating the RNA update procedure. The network may update the UE context for the remote UE and / or the relay UE in response to receiving the first message.

[0134] In some embodiments, the UE has a connection established with the network in the RRC inactive state. In these embodiments, timer information may be received from the network in an RRC release message, and the first message may be transmitted to the network as part of a random access request to transition the established connection from the RRC inactive state to the RRC connected state.

[0135] Alternatively, in some embodiments, the UE has a connection established with the network in the RRC connected state. In these embodiments, the timer information may be received from the network via an RRC configuration message. The timer information may include a periodic registration timer for the UE to periodically transmit message transmissions to initiate an RNA update procedure.

[0136] At 1906, an acknowledgment message is received from the network, the acknowledgment message including updated connection information for the first remote device. The acknowledgment message may specify the next time for the first remote UE, the second remote UE, and / or the relay UE to perform a subsequent RNA update procedure.

[0137] At 1908, the updated connection information for the first remote device is transmitted to the first remote device. When the relay UE is serving multiple remote UEs, the relay UE may additionally transmit the corresponding updated connection information to the other remote UEs as well. The remote UE may reset the corresponding T380 timers of these remote UEs in response to receiving the updated connection information. Alternatively, when the T380 timer is directly maintained by the relay UE, the relay UE may reset the T380 timer when receiving the acknowledgment message from the network.

[0138] Another exemplary embodiment may include an apparatus that includes: an antenna; radio components coupled to the antenna; and a processing element operatively coupled to the radio components, wherein the apparatus is configured to implement any or all parts of the foregoing examples.

[0139] Yet another exemplary embodiment may include a non-transitory computer-accessible memory medium including program instructions that, when executed at a device, cause the device to implement any or all parts of any one of the foregoing examples.

[0140] Still another exemplary embodiment may include a computer program including instructions for performing any or all parts of any one of the foregoing examples.

[0141] Yet another exemplary embodiment may include an apparatus including means for performing any or all elements of any one of the foregoing examples.

[0142] Another exemplary embodiment may include an apparatus including a processing element configured to cause a wireless device to perform any element or all elements of any one of the foregoing examples.

[0143] It is well known that the use of personally identifiable information should follow privacy policies and practices that are generally recognized as meeting or exceeding industry or government requirements for maintaining user privacy. Specifically, personally identifiable information data should be managed and processed to minimize the risk of inadvertent or unauthorized access or use, and the nature of authorized use should be clearly explained to users.

[0144] Embodiments of the present invention may be implemented in any of a variety of forms. For example, in some embodiments, the present invention may be implemented as a computer-implemented method, a computer-readable memory medium, or a computer system. In other embodiments, the present invention may be implemented using one or more custom-designed hardware devices such as an ASIC. In still other embodiments, the present invention may be implemented using one or more programmable hardware elements such as an FPGA.

[0145] In some embodiments, a non-transitory computer-readable memory medium (e.g., a non-transitory memory element) may be configured to store program instructions and / or data, wherein if the program instructions are executed by a computer system, the computer system is caused to perform a method, such as any one of the method embodiments described herein, or any combination of the method embodiments described herein, or any subset of any of the method embodiments described herein, or any combination of such subsets.

[0146] In some embodiments, a device (e.g., a UE) may be configured to include a processor (or a set of processors) and a memory medium (or memory elements), where the memory medium stores program instructions, where the processor is configured to read and execute the program instructions from the memory medium, and where the program instructions are executable to implement any one of the various method embodiments described herein (or any combination of the method embodiments described herein, or any subset of any of the method embodiments described herein or any combination of such subsets). The device may be implemented in any of a variety of forms.

[0147] Although the above embodiments have been described in considerable detail, many variations and modifications will become apparent to those skilled in the art once the above disclosure is fully understood. The present disclosure is intended that the following claims be construed to cover all such variations and modifications.

Claims

1. A user equipment (UE) comprising: radio components; and a processor operatively coupled to the radio components, wherein the UE is configured to: establish a first relay connection with a first remote device, wherein the first relay connection relays communication between the first remote device and a network; establish a second relay connection with a second remote device, wherein the second relay connection relays communication between the second remote device and the network; transmit a first message to the network for initiating a radio access network based notification area (RNA) update procedure for the first remote device, for the second remote device, and for the UE; receive an acknowledgement message from the network, the acknowledgement message including updated connection information of the first remote device and updated connection information of the second remote device; transmit the updated connection information of the first remote device to the first remote device; and transmit the updated connection information of the second remote device to the second remote device.

2. The UE according to claim 1, wherein the UE is further configured to: receive first timer information from the first remote device; determine, based on the first timer information, that a timer associated with the first remote device has expired, wherein the first message is transmitted to the network in response to determining that the timer has expired.

3. The UE according to claim 2, wherein the UE is further configured to: transmit a keep-alive message to the first remote device via a PC5 interface before the timer expires.

4. The UE according to claim 1, wherein the UE is further configured to: receive first timer information from the first remote device; receive second timer information from the second remote device; and determine, based on the first timer information or the second timer information, that a timer associated with the first remote device or the second remote device has expired, wherein the first message is transmitted to the network in response to determining that the timer has expired.

5. The UE according to claim 4, wherein the timer comprises a T380 timer.

6. The UE according to claim 1, wherein the first message further initiates the RNA update procedure for the UE.

7. The UE according to claim 1, wherein the UE is further configured to: receive timer information related to the RNA update procedure for the first remote device from the network; determine, based on the timer information, that a timer associated with the first remote device has expired; wherein the first message is transmitted to the network in response to determining that the timer has expired.

8. The UE according to claim 7, wherein the UE has a connection established with the network in a radio resource control (RRC) inactive state. wherein the timer information is received from the network in an RRC release message, and wherein the first message is transmitted to the network as part of a random access request to transition the established connection from the RRC inactive state to the RRC connected state.

9. The UE according to claim 7, wherein the UE has an established connection with the network in a Radio Resource Control (RRC) connected state, and wherein the timer information is received from the network via an RRC configuration message.

10. The UE according to claim 7, wherein the UE has an established connection with the network in a Radio Resource Control (RRC) connected state, and wherein the timer information includes a periodic registration timer for the UE to periodically transmit message transfers to initiate an RNA update process.

11. An apparatus for wireless communication, comprising: a processor configured to cause a User Equipment (UE) device to: establish a first relay connection with a first remote device, wherein the first relay connection relays communication between the first remote device and the network; establish a second relay connection with a second remote device, wherein the second relay connection relays communication between the second remote device and the network; transmit a first message to the network for the first remote device, for the second remote device, and for the UE to initiate a Radio Access Network-based Notification Area (RNA) update process; receive an acknowledgment message from the network, the acknowledgment message including updated connection information of the first remote device and updated connection information of the second remote device; transmit the updated connection information of the first remote device to the first remote device; and transmit the updated connection information of the second remote device to the second remote device.

12. The apparatus according to claim 11, wherein the processor is further configured to cause the UE to: receive first timer information from the first remote device; determine, based on the first timer information, that a timer associated with the first remote device has expired, wherein the first message is transmitted to the network in response to determining that the timer has expired.

13. The apparatus according to claim 12, wherein the processor is further configured to cause the UE to: transmit a keep-alive message to the first remote device via a PC5 interface before the timer expires.

14. The apparatus according to claim 11, wherein the processor is further configured to cause the UE to: receive first timer information from the first remote device; receive second timer information from the second remote device; and determine, based on the first timer information or the second timer information, that a timer associated with the first remote device or the second remote device has expired, wherein the first message is transmitted to the network in response to determining that the timer has expired.

15. The apparatus according to claim 14, wherein the timer includes a T380 timer.

16. The apparatus according to claim 11, Wherein the first message further initiates the RNA update process for the UE.

17. The apparatus according to claim 11, wherein the processor is further configured to cause the UE to: Receive timer information related to the RNA update process for the first remote device from the network, Determine, based on the timer information, that a timer associated with the first remote device has expired, Wherein the first message is transmitted to the network in response to determining that the timer has expired.

18. The apparatus according to claim 17, Wherein the UE has a connection established with the network in a Radio Resource Control (RRC) inactive state, Wherein the timer information is received from the network in an RRC release message, and wherein the first message is transmitted to the network as part of a random access request to transition the established connection from the RRC inactive state to an RRC connected state.

19. The apparatus according to claim 17, Wherein the UE has a connection established with the network in a Radio Resource Control (RRC) connected state, and Wherein the timer information is received from the network via an RRC configuration message.

20. The apparatus according to claim 17, Wherein the UE has a connection established with the network in a Radio Resource Control (RRC) connected state, and Wherein the timer information includes a periodic registration timer for the UE to periodically transmit message transfers to initiate the RNA update process.

21. A method performed by a relay User Equipment (UE) device, the method comprising: Establishing a first relay connection with a first remote device, wherein the first relay connection relays communication between the first remote device and a network; Establishing a second relay connection with a second remote device, wherein the second relay connection relays communication between the second remote device and the network; Transmitting a first message for initiating a Radio Access Network (RAN)-based Notification Area (RNA) update process for the first remote device, for the second remote device, and for the UE to the network; Receiving an acknowledgement message from the network, the acknowledgement message including updated connection information for the first remote device and updated connection information for the second remote device; Transmitting the updated connection information for the first remote device to the first remote device; And Transmitting the updated connection information for the second remote device to the second remote device.

22. The method according to claim 21, further comprising: Receiving first timer information from the first remote device; Determining, based on the first timer information, that a timer associated with the first remote device has expired, wherein the first message is transmitted to the network in response to determining that the timer has expired.

23. The method according to claim 22, further comprising: Before the timer expires, transmitting a keep-alive message to the first remote device via a PC5 interface.

24. The method according to claim 21, further comprising: Receiving first timer information from the first remote device; Receive second timer information from the second remote device; And Determine, based on the first timer information or the second timer information, that a timer associated with the first remote device or the second remote device has expired, Wherein the first message is transmitted to the network in response to determining that the timer has expired.

25. The method according to claim 24, Wherein the timer includes a T380 timer.

26. The method according to claim 21, Wherein the first message further initiates the RNA update procedure for the UE.

27. The method according to claim 21, further comprising: Receive timer information related to the RNA update procedure for the first remote device from the network, Determine, based on the timer information, that a timer associated with the first remote device has expired, Wherein the first message is transmitted to the network in response to determining that the timer has expired.

28. The method according to claim 27, Wherein the UE has a connection established with the network in the radio resource control (RRC) inactive state, Wherein the timer information is received from the network in an RRC release message, and wherein the first message is transmitted to the network as part of a random access request to transition the established connection from the RRC inactive state to the RRC connected state.

29. The method according to claim 27, Wherein the UE has a connection established with the network in the radio resource control (RRC) connected state, and Wherein the timer information is received from the network via an RRC configuration message.

30. The method according to claim 27, Wherein the UE has a connection established with the network in the radio resource control (RRC) connected state, and Wherein the timer information includes a periodic registration timer for the UE to periodically transmit message transfers to initiate the RNA update procedure.

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