Radio resource control connection procedure for remote wireless devices

Abstract

The present disclosure relates to a radio resource control connection procedure for remote wireless devices. In particular, a method comprising: by a relay wireless device: receiving, from a plurality of remote wireless devices, respective radio resource control, RRC, connection requests; and relaying, between a cellular base station and each remote wireless device of the plurality of remote wireless devices, RRC messages to establish an RRC connection with the cellular base station, the RRC messages comprising respective RRC setup complete messages, wherein each RRC setup complete message is relayed between the respective remote wireless device of the plurality of remote wireless devices and the cellular base station on a Uu link between the relay wireless device and the cellular base station and is transmitted on the Uu link with a respective remote wireless device identifier to distinguish the respective RRC setup complete messages for different remote wireless devices.

Description

[0001] This application is a divisional application of the invention patent application filed on August 13, 2019, with application number 201910746189.1 and entitled "Radio Resource Control Connection Process for Remote Wireless Device". Technical Field

[0002] This patent application relates to wireless communication, including a radio resource control connection process for a remote wireless device in a wireless communication system. Background Technology

[0003] The use of wireless communication systems is growing rapidly. Furthermore, wireless communication technology has evolved from voice communication only to include the transmission of data (such as the internet and multimedia content).

[0004] Mobile electronic devices can take the form of smartphones or tablets that users typically carry. Wearable devices (also known as accessory devices) are a newer form of mobile electronic device, an example being a smartwatch. Additionally, low-cost, low-complexity wireless devices designed for static or dynamic deployment are rapidly increasing as part of the development of the “Internet of Things”. In other words, the required devices are becoming increasingly diverse in terms of complexity, capabilities, traffic patterns, and other characteristics. Generally, it should be expected that improved support for a wide range of desired wireless communication features will be recognized and provided. Therefore, improvements in this field are anticipated. Summary of the Invention

[0005] This article presents implementation schemes for systems, apparatuses, and methods, particularly for performing radio resource control connection processes on remote wireless devices in wireless communication systems.

[0006] As mentioned above, the number of use cases for different types of wireless devices with broad variability and usage expectations is increasing. One direction for expanding potential use cases supported by wireless communication technologies may include the development of low-cost and / or low-power wireless devices. The practicality of such low-cost and / or low-power wireless devices can be increased by enabling them to establish radio resource control connections and gain access to cellular networks through intermediate relay wireless devices.

[0007] Therefore, the techniques described herein include techniques for: a remote wireless device providing an RRC message relayed to a cellular base station to a relay wireless device; a cellular base station providing an RRC message relayed to a remote wireless device to a relay wireless device; and a relay wireless device relaying such messages between a cellular base station and a remote wireless device.

[0008] In addition, the techniques described herein include techniques for combining remote radio resource control connection detection of link failures and link failure handling, both of which are used for wireless links between remote wireless devices and relay wireless devices, as well as for wireless links between relay wireless devices and cellular base stations.

[0009] The techniques described herein may be implemented in and / or used in conjunction with several different types of devices, including but not limited to any one of the following computing devices: cellular phones, tablets, accessory and / or wearable computing devices, portable media players, cellular base stations and other cellular network infrastructure devices, servers, and various other computing devices.

[0010] The present invention is intended to provide a brief overview of some of the subjects described in this document. Therefore, it should be understood that the above features are merely illustrative and should not be construed as narrowing the scope or essence of the subjects described herein in any way. Other features, aspects, and advantages of the subjects described herein will become apparent from the following detailed description, drawings, and claims. Attached Figure Description

[0011] A better understanding of the subject matter can be obtained by considering the following detailed description of the implementation scheme in conjunction with the accompanying drawings.

[0012] Figure 1 An exemplary wireless communication system including accessory devices according to some embodiments is shown;

[0013] Figure 2 An exemplary wireless communication system is shown, according to some embodiments, in which two wireless devices are able to perform direct device-to-device communication;

[0014] Figure 3 This is a block diagram illustrating an exemplary wireless device according to some implementation schemes;

[0015] Figure 4 This is a block diagram illustrating an exemplary base station according to some implementation schemes;

[0016] Figure 5 This is a communication flowchart illustrating an exemplary method for performing presence detection in a wireless communication system according to some implementation schemes;

[0017] Figure 6 Aspects of possible wireless communication relay between a remote UE, a relay UE, and a gNB according to some implementation schemes are illustrated;

[0018] Figures 7 to 8Exemplary aspects of a possible protocol stack architecture for user plane and control plane communication in a 3GPP-based UE-to-network relay framework are shown according to some implementation schemes.

[0019] Figure 9 This is a signal flow diagram illustrating various aspects of an exemplary scenario according to some implementation schemes, in which multiple remote UEs attempt to establish an RRC connection with a gNB via the same relay UE;

[0020] Figure 10 This is a signal flow diagram illustrating an aspect of an exemplary scenario according to some implementations, in which a single remote UE attempts to establish an RRC connection with a gNB via a relay UE;

[0021] Figure 11 This is a signal flow diagram illustrating an aspect of an exemplary scenario according to some implementations, in which a single remote UE attempts to re-establish an RRC connection with the gNB via a relay UE;

[0022] Figure 12 This is a signal flow diagram illustrating an aspect of an exemplary scenario according to some implementations, in which a single remote UE attempts to restore its RRC connection with the gNB via a relay UE;

[0023] Figure 13 This is a signal flow diagram illustrating an aspect of an exemplary scenario according to some implementation schemes, wherein the gNB releases a remote RRC connection with a remote UE via a relay UE;

[0024] Figure 14 This is a signal flow diagram illustrating an aspect of an exemplary scenario according to some implementations, wherein the gNB reconfigures a remote RRC connection with a remote UE via a relay UE;

[0025] Figure 15 This is a signal flow diagram illustrating an aspect of an exemplary scenario according to some implementations, where the establishment of a remote RRC connection fails due to a link failure between the relay UE and the gNB;

[0026] Figure 16 This is a signal flow diagram illustrating an aspect of an exemplary scenario according to some implementations, in which remote RRC connection re-establishment fails due to a link failure between the relay UE and the gNB;

[0027] Figure 17 This is a signal flow diagram illustrating an aspect of an exemplary scenario according to some implementations, where a remote RRC connection recovery failure occurs due to a link failure between the relay UE and the gNB;

[0028] Figure 18This is a signal flow diagram illustrating an aspect of an exemplary scenario according to some implementations, in which a relay UE uses a response validity timer to detect link failure between the relay UE and the remote UE;

[0029] Figure 19 This is a signal flow diagram illustrating an aspect of an exemplary scenario according to some implementations, in which a relay UE uses a response validity timer to detect a PC5 interface failure between the relay UE and the remote UE;

[0030] Figure 20 This is a signal flow diagram illustrating an aspect of an exemplary scenario according to some implementation schemes, in which, in response to a link failure between a remote UE and a relay UE, the remote UE uses a response protection timer.

[0031] Figure 21 This is a signal flow diagram illustrating an aspect of an exemplary scenario according to some implementation schemes, where the establishment of a remote RRC connection fails due to a link failure between the relay UE and the remote UE;

[0032] Figure 22 This is a signal flow diagram illustrating an aspect of an exemplary scenario according to some implementations, where remote RRC connection re-establishment fails due to a link failure between the relay UE and the remote UE; and

[0033] Figure 23 This is a signal flow diagram illustrating an aspect of an exemplary scenario according to some implementations, where a remote RRC connection recovery failure occurs due to a link failure between the relay UE and the remote UE.

[0034] While the features described herein are susceptible to various modifications and alternatives, specific embodiments thereof are shown by way of example in the accompanying 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 this document to the specific forms disclosed, but rather are intended to cover all modifications, equivalents and alternatives falling within the substance and scope of the subject matter as defined by the appended claims. Detailed Implementation

[0035] acronym

[0036] The following acronyms are used in this disclosure.

[0037] 3GPP: Third Generation Partnership Project

[0038] 3GPP2: Third Generation Partnership Project 2

[0039] GSM: Global System for Mobile Communications

[0040] UMTS: Universal Mobile Telecommunications System

[0041] LTE: Long Term Evolution

[0042] IoT: Internet of Things

[0043] NB: Narrowband

[0044] D2D: Device to Device

[0045] OOC: Outside of coverage area

[0046] the term

[0047] The following are definitions of the terms used in this disclosure:

[0048] Memory media—any of various types of nontransitory memory devices or storage devices. The term "memory media" is intended to include mounting media such as CD-ROMs, floppy disks, or magnetic 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. Memory media may also include other types of nontransitory memory or combinations thereof. Furthermore, memory media may reside in a first computer system executing a program, or may reside in a different second computer system connected to the first computer system via a network such as the Internet. In the latter case, the second computer system may provide program instructions to the first computer for execution. The term "memory media" may include two or more memory media that may reside in different locations on different computer systems connected via a network, for example. Memory media may store program instructions (e.g., manifested as a computer program) that can be executed by one or more processors.

[0049] Carrier media—memory media as described above, and physical transmission media such as buses, networks, and / or other physical transmission media that transmit signals such as electrical signals, electromagnetic signals, or digital signals.

[0050] Programmable hardware elements—including a variety of hardware devices comprising multiple programmable functional blocks connected via programmable interconnects. Examples include FPGAs (Field-Programmable Gate Arrays), PLDs (Programmable Logic Devices), FPOAs (Field-Programmable Object Arrays), and CPLDs (Complex PLDs). Programmable functional blocks can vary from fine-grained (combinatorial logic units or lookup tables) to coarse-grained (arithmetic logic units or processor cores). Programmable hardware elements may also be referred to as “configurable logic units.”

[0051] Computer system—any of all types of computing or processing systems, including personal computer systems (PCs), mainframe computer systems, workstations, network devices, internet devices, personal digital assistants (PDAs), television systems, grid computing systems, or other devices or combinations thereof. In general, the term "computer system" can be broadly defined to encompass any device (or combination of devices) having at least one processor that executes instructions from a memory medium.

[0052] User equipment (UE) (or “UE device”) – any of various types of computer systems or devices that are mobile or portable and perform wireless communications. Examples of UE devices include mobile phones or smartphones (e.g., iPhone). TM Based on Android TM Phones), tablets (e.g., iPads) TM Samsung Galaxy TM ), portable gaming devices (e.g., Nintendo DS) TM PlayStation Portable TM Gameboy Advance TM iPhone TM Laptops, wearable devices (e.g., smartwatches, smart glasses), PDAs, portable internet devices, music players, data storage devices, or other handheld devices, etc. Generally, the term "UE" or "UE device" can be broadly defined as any electronic device, computing device, and / or telecommunications device (or combination of devices) that is easily transportable by the user and capable of wireless communication.

[0053] Wireless device – any of various types of computer systems or devices that perform wireless communication. A wireless device can be portable (or mobile), or it can be fixed or stationary. A UE is an example of a wireless device.

[0054] Communication device – any of various types of computer systems or devices that perform communication, which may be wired or wireless. A communication device may be portable (or mobile), or it may be fixed or stationary. A wireless device is one example of a communication device. A UE is another example of a communication device.

[0055] Base station – The term “base station” has the full range of its common meaning and includes at least a wireless communication station that is installed in a fixed location and used for communication as part of a wireless communication system.

[0056] Link budget constrained—encompassing the full range of its general meaning, and at least including the characteristics of a wireless device (e.g., a UE) that exhibits limited communication capabilities or limited power relative to devices that are not link budget constrained or relative to devices for which a Radio Access Technology (RAT) standard has been developed. Link budget constrained wireless devices may suffer from relatively limited receiving and / or transmitting capabilities, which may be due to one or more factors such as device design, device size, battery size, antenna size or design, transmit power, receive power, current transmission medium conditions, and / or other factors. Such devices may be referred to herein as “link budget constrained” (or “link budget limited”) devices. Devices may be inherently link budget constrained due to their size, battery power, and / or transmit / receive power. For example, a smartwatch communicating with a base station via LTE or LTE-A may be inherently link budget constrained due to its reduced transmit / receive power and / or reduced antenna. Wearable devices such as smartwatches are generally link budget constrained devices. Alternatively, the device may not be inherently link budget limited, for example, it may have sufficient size, battery power, and / or transmit / receive power for normal communication via LTE or LTE-A, but may be temporarily link budget limited due to current communication conditions, such as a smartphone at the cell edge. It should be noted that the term "link budget limited" includes or encompasses power limitations, and therefore a link-limited device can be considered a link budget-limited device.

[0057] A processing element (or processor) is a component or combination of components capable of performing the functions of a device (such as a user equipment device or a cellular network device). A processing element may include, for example: a processor and associated memory, portions or circuitry of individual processor cores, an entire processor core, a single processor, a processor array, circuitry such as an ASIC (Application-Specific Integrated Circuit), programmable hardware components such as a Field-Programmable Gate Array (FPGA), and any combination thereof.

[0058] Automatic—refers to actions or operations performed by a computer system (e.g., software executed by the computer system) or device (e.g., circuitry, programmable hardware components, ASICs, etc.) without requiring direct user input to specify or perform the actions or operations. Therefore, the term "automatic" contrasts with actions performed or specified manually by the user, where the user provides input to directly perform the action. An automatic process can be initiated by user-provided input, but the subsequent actions performed "automatically" are not specified by the user; that is, they are not performed "manually," where the user specifies each action to be performed. For example, a user filling out a form by selecting each field and providing input specifying information (e.g., by typing information, selecting a checkbox, selecting a radio component, etc.) is equivalent to manually filling out the form, even though the computer system must update the form in response to the user's actions. The form can be automatically filled out by a computer system, where the computer system (e.g., software executed on the computer system) analyzes the fields of the form and fills it out without any user input specifying answers for the fields. As indicated above, the user can invoke the automatic filling of the form but does not participate in the actual filling of the form (e.g., the user does not manually specify answers for the fields, but they are completed automatically). This manual provides various examples of operations that are automatically performed in response to actions taken by the user.

[0059] "Configured as" – Various components can be described as being "configured to" perform one or more tasks. In such contexts, "configured as" is a broad expression generally referring to a "structure" that "has" perform one or more tasks during operation. Thus, a component can be configured to perform a task even when it is not currently performing one (e.g., a set of electrical conductors can be configured to electrically connect one module to another, even when the two modules are not connected). In some contexts, "configured as" can be a broad expression generally referring to a structure that "has" perform one or more tasks during operation. Thus, a component can be configured to perform a task even when it is not currently powered on. Typically, the circuit system forming the structure corresponding to "configured as" may include hardware circuitry.

[0060] 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". The statement that a component is configured to perform one or more tasks is explicitly intended not to invoke the interpretation of paragraph 6 of §112 of 35 U.S.SC for that component.

[0061] Figures 1-2 Wireless communication system

[0062] Figure 1 An example of a wireless cellular communication system is illustrated. It should be noted that... Figure 1This represents one of many possibilities, and the features of this disclosure can be implemented in any of various systems as needed. For example, the embodiments described herein can be implemented in any type of wireless device.

[0063] As shown in the figure, an exemplary wireless communication system includes a cellular base station 102 that communicates with one or more wireless devices 106A, 106B, etc., and an accessory device 107 via a transmission medium. Wireless devices 106A, 106B, and 107 may be user equipment, which may be referred to herein as a "user equipment" (UE) or UE device.

[0064] Base station 102 may be a transceiver base station (BTS) or a cell site and may include hardware and / or software to enable wireless communication with UE devices 106A, 106B, and 107. If base station 102 is implemented in an LTE environment, it may be referred to as an "eNodeB" or "eNB". If base station 102 is implemented in a 5G NR environment, it may alternatively be referred to as a "gNodeB" or "gNB". Base station 102 may also be equipped to communicate with network 100 (e.g., the core network of a cellular service provider, telecommunications networks such as the Public Switched Telephone Network (PSTN), and / or the Internet, and various other possibilities). Therefore, base station 102 may facilitate communication between UE devices 106 and 107 and / or communication between UE devices 106 / 107 and network 100. Also as used herein, in relation to a UE, a base station may sometimes be considered to represent a network, taking into account both uplink and downlink communication of the UE. Therefore, a UE communicating with one or more base stations in the network may also be interpreted as a UE communicating with the network.

[0065] In other specific implementations, base station 102 may be configured to provide communication via one or more other wireless technologies, such as an access point supporting one or more WLAN protocols, such as 802.11a, b, g, n, ac, ad and / or ax, or LTE in an unlicensed band (LAA).

[0066] The communication area (or coverage area) of base station 102 may be referred to as a "cell". Base station 102 and UE 106 / 107 may be configured to communicate using any of the following technologies via a transmission medium: Radio Access Technology (RAT), LTE, Advanced LTE (LTE-A), NR, HSPA, 3GPP2 CDMA2000 (e.g., 1xRTT, 1xEV-DO, HRPD, eHRPD), Wi-Fi, etc.

[0067] Therefore, base station 102 and other similar base stations (not shown) operating according to one or more cellular communication technologies can be provided as a cell network that can provide continuous or near-continuous overlapping services to UE devices 106A-N and 107 and similar devices within a geographical area via one or more cellular communication technologies.

[0068] It should be noted that, at least in some cases, UE devices 106 / 107 may be able to communicate using any of a variety of wireless communication technologies. For example, UE devices 106 / 107 may be configured to communicate using one or more of the following: GSM, UMTS, CDMA2000, LTE, LTE-A, NR, WLAN, Bluetooth, one or more Global Navigation Satellite Systems (GNSS, such as GPS or GLONASS), one and / or more mobile television broadcasting standards (e.g., ATSC-M / H). Other combinations of wireless communication technologies (including more than two wireless communication technologies) are also possible. Similarly, in some cases, UE devices 106 / 107 may be configured to communicate using only a single wireless communication technology.

[0069] UEs 106A and 106B may include handheld devices such as smartphones or tablets, and / or may include any of a variety of devices with cellular communication capabilities. For example, one or more of UEs 106A and 106B may be wireless devices designed for static or dynamic deployment, such as home appliances, measuring devices, control devices, etc. UE 106B may be configured to communicate with UE device 107, which may be referred to as accessory device 107. Accessory device 107 may be any of a variety of wireless devices, typically a wearable device with a small form factor and limited battery, output power, and / or communication capabilities relative to UE 106. As a common example, UE 106B may be a smartphone carried by a user, and accessory device 107 may be a smartwatch worn by the same user. UE 106B and accessory device 107 may communicate using any of a variety of short-range communication protocols such as Bluetooth or Wi-Fi. In some cases, UE106B and accessory device 107 may perform direct peer-to-peer communication using Proximity Service (ProSe) technology (e.g., in a manner supported by a cellular base station). For example, such ProSe communication may be performed as part of a relay link to support a radio resource control connection between accessory device 107 and BS 102, as described in the various embodiments herein.

[0070] UE 106B can also be configured to communicate with UE 106A. For example, UE 106A and UE 106B may be able to perform direct device-to-device (D2D) communication. D2D communication may be supported by cellular base station 102 (e.g., easily discovered by BS 102, and with various possible forms of assistance), or may be performed in a manner not supported by BS 102. For example, it is possible that UE 106A and UE 106B can deploy and perform D2D communication (e.g., including discovery communication) even when BS 102 and other cellular base stations have no coverage.

[0071] Figure 2 An exemplary BS 102 is shown communicating with UE device 106, which in turn communicates with accessory device 107. UE device 106 and accessory device 107 can be mobile phones, tablets or any other type of handheld device, smartwatches or other wearable devices, media players, computers, laptops, or virtually any type of wireless device. In some embodiments, the accessory device may be a wireless device designed to have low cost and / or low power consumption and may support communication with BS 102 thanks to a relay link with UE device 106 (and / or another companion device). For example, in Figure 2 In the exemplary scenarios described herein, a device that communicates with a cellular base station using a relay link with another wireless device may also be referred to herein as a remote wireless device, a remote device, or a remote UE device, and a wireless device providing such a relay link may also be referred to herein as a relay wireless device, a relay device, or a relay UE device. According to some implementations, such BS 102, UE 106, and accessory device 107 may be configured to perform radio resource control procedures on the remote wireless device according to the various techniques described herein.

[0072] Both UE 106 and accessory device 107 may include a device or integrated circuit referred to as a cellular modem for facilitating cellular communication. The cellular modem may include one or more processors (processing elements) configured to execute program instructions stored in memory and / or various hardware components described herein. UE 106 and / or accessory device 107 may each perform any of the method embodiments described herein by executing such stored instructions. Alternatively or in addition, UE 106 and / or accessory device 107 may also include programmable hardware elements, such as FPGAs (Field-Programmable Gate Arrays), integrated circuits, and / or any of various other possible hardware components configured to perform (e.g., individually or in combination) any of the method embodiments described herein or any portion thereof. The cellular modem described herein can be used in UE devices as defined herein, wireless devices as defined herein, or communication devices as defined herein. The cellular modem described herein can also be used in base stations or other similar network-side devices.

[0073] UE 106 and / or accessory device 107 may include one or more antennas for communicating according to one or more RAT standards using one or more wireless communication protocols. In some embodiments, one or both of UE 106 or accessory device 107 may be configured to communicate using a single shared radio component. The shared radio component may be coupled to a single antenna or to multiple antennas (e.g., for MIMO) for performing wireless communication. Typically, the radio component may include any combination of a baseband processor, analog 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 component may use the aforementioned hardware to implement one or more receive chains and transmit chains.

[0074] Alternatively, UE 106 and / or accessory device 107 may include two or more radio components. For example, in some embodiments, UE 106 or accessory device 107 may include separate transmit and / or receive chains (e.g., including separate antennas and other radio components) for each wireless communication protocol configured to communicate therewith. As another possibility, UE 106 and / or accessory device 107 may include one or more radio components shared among multiple wireless communication protocols, as well as one or more radio components uniquely used by a single wireless communication protocol. For example, UE 106 and / or accessory device 107 may include shared radio components for communication using either LTE or CDMA2000 1xRTT (or LTE or NR, or LTE or GSM), and for communication using Wi-Fi and BLUETOOTH. TM Each component communicates independently. Other configurations are also possible.

[0075] Figure 3 Block diagram of UE device

[0076] Figure 3 A possible block diagram of a UE device, such as UE device 106 or 107, is shown. As shown, UE device 106 / 107 may include a system-on-a-chip (SOC) 300, which may include components for various purposes. For example, as shown, SOC 300 may include: a processor 302 that executes program instructions for UE device 106 / 107; and a display circuitry system 304 that performs graphics processing and provides display signals to a display 360. SOC 300 may also include a motion sensing circuitry system 370 that may detect motion of UE 106, for example, using a gyroscope, accelerometer, and / or any of various other motion sensing components. Processor 302 may also be coupled to memory management unit (MMU) 340, which may be configured to receive addresses from processor 302 and translate those addresses into locations in memory (e.g., memory 306, read-only memory (ROM) 350, flash memory 310) and / or other circuitry or devices, such as display circuitry system 304, radio components 330, 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 in the figure, the SOC 300 can be coupled to various other circuits of the UE 106 / 107. For example, the UE 106 / 107 may include various types of memory (e.g., including NAND flash memory 310), connector interface 320 (e.g., for coupling to computer systems, docking stations, charging stations, etc.), display 360, and wireless communication circuitry 330 (e.g., for LTE, LTE-A, NR, CDMA2000, Bluetooth, Wi-Fi, NFC, GPS, etc.).

[0078] UE device 106 / 107 may include at least one antenna and, in some embodiments, may include multiple antennas 335a and 335b for performing wireless communication with a base station and / or other devices. For example, UE device 106 / 107 may use antennas 335a and 335b to perform wireless communication. As described above, UE device 106 / 107 may be configured in some embodiments to perform wireless communication using multiple wireless communication standards or radio access technologies (RATs).

[0079] The wireless communication circuitry system 330 may include a Wi-Fi logic component 332, a cellular modem 334, and a Bluetooth logic component 336. The Wi-Fi logic component 332 enables the UE device 106 / 107 to perform Wi-Fi communication over an 802.11 network. The Bluetooth logic component 336 enables the UE device 106 / 107 to perform Bluetooth communication. The cellular modem 334 may be a low-power cellular modem capable of performing cellular communication according to one or more cellular communication technologies.

[0080] As described herein, UE 106 / 107 may include hardware and software components for implementing embodiments of this disclosure. The processor 302 of UE device 106 / 107 may be configured to implement some 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, 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). Furthermore, processor 302 may be coupled to, for example, Figure 3Other components shown and / or interoperable with them can perform radio resource control procedures for remote wireless devices according to various embodiments disclosed herein. Processor 302 may also implement various other applications and / or end-user applications running on UE 106. Alternatively or additionally, one or more components of the wireless communication circuitry 330 of UE device 106 / 107 (e.g., cellular modem 334) may be configured, for example, by executing program instructions stored on a memory medium (e.g., a non-transitory computer-readable memory medium), a processor configured as an FPGA (Field-Programmable Gate Array), and / or a processor using dedicated hardware components that may include ASICs (Application-Specific Integrated Circuits) to implement part or all of the methods described herein.

[0081] Figure 4 Block diagram of a base station

[0082] Figure 4 An exemplary block diagram of a base station 102 according to some embodiments is shown. It should be noted that... Figure 4 The base station shown is merely one example of a possible base station. As illustrated, base station 102 may include a processor 404 capable of executing program instructions specific to base station 102. Processor 404 may also be coupled to a memory management unit (MMU) 440 (which may be configured to receive addresses from processor 404 and translate those addresses into locations in memory (e.g., memory 460 and read-only memory (ROM) 450)) or to other circuitry or devices.

[0083] Base station 102 may include at least one network port 470. (As mentioned above...) Figure 1 and Figure 2 As described herein, network port 470 can be configured to be coupled to a telephone network and provide access to multiple devices, such as UE devices 106 / 107, that have access to the telephone network.

[0084] Network port 470 (or an additional network port) may be further configured, or alternatively configured, to be coupled to a cellular network, such as the core network of a cellular service provider. This core network may provide mobility-related services and / or other services to multiple devices such as UE devices 106 / 107. For example, the core network may include, for instance, a Mobility Management Entity (MME) for providing mobility management services, a Serving Gateway (SGW) and / or a Packet Data Network Gateway (PGW) for providing external data connections such as to the Internet, and so on. In some cases, network port 470 may be coupled to a telephone network via the core network, and / or the core network may provide a telephone network (e.g., between other UE devices served by the cellular service provider).

[0085] Base station 102 may include at least one antenna 434 and possibly multiple antennas. One or more antennas 434 may be configured to operate as wireless transceivers and may be further configured to communicate with UE devices 106 / 107 via radio component 430. One or more antennas 434 communicate 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 configured to communicate via various wireless communication standards, including but not limited to LTE, LTE-A, NR, GSM, UMTS, CDMA2000, Wi-Fi, etc.

[0086] Base station 102 can be configured to perform wireless communication using multiple wireless communication standards. In some cases, base station 102 may include multiple radio components that enable base station 102 to communicate according to multiple wireless communication technologies. For example, as one possibility, base station 102 may include an LTE radio component for performing communication according to LTE and a Wi-Fi radio component for performing communication according to Wi-Fi. In such a case, base station 102 may be able to operate as both an LTE base station and a Wi-Fi access point. As another possibility, base station 102 may include a multimode radio component capable of performing communication according to any of multiple wireless communication technologies (e.g., LTE and NR, LTE and Wi-Fi, LTE and UMTS, LTE and CDMA2000, UMTS and GSM, etc.).

[0087] As further described herein, BS 102 may include hardware and software components for implementing or supporting embodiments of the features described herein. According to some embodiments, the processor 404 of base station 102 may be configured to implement some 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 a FPGA (Field-Programmable Gate Array), or as an ASIC (Application-Specific Integrated Circuit), or a combination thereof. Alternatively (or additionally), in conjunction with one or more of other components 430, 432, 434, 440, 450, 460, 470, the processor 404 of BS 102 may be configured to implement or support the implementation of radio resource control procedures for remote wireless devices according to various embodiments disclosed herein and / or various other features described herein.

[0088] Figure 5 Communication flowchart

[0089] Figure 5This is a communication flowchart illustrating a method for performing radio resource control procedures on a remote wireless device in a wireless communication system, according to some embodiments. In various embodiments, some of the method elements shown may be performed simultaneously in a different order than shown, may be replaced by other method elements, or may be omitted. Additional method elements may also be performed as needed.

[0090] Figure 5 Various aspects of the method can be derived from wireless devices and / or cellular base stations, such as in Figures 1 to 4 Shown in and relative to Figures 1 to 4 The UE 106A-B and / or BS 102 described herein may be implemented, or more generally, may be implemented in other devices in combination with any of the computer systems or devices shown in the above figures, as needed. It should be noted that while described in a manner involving the use of communication technologies and / or features associated with LTE, NR, and / or 3GPP specification documents... Figure 5 This description describes at least some elements of the method, but it is not intended to limit this disclosure and can be used in any suitable wireless communication system as needed. Figure 5 The method can be implemented in various aspects, as shown in the figure.

[0091] In 502, a wireless device (“first wireless device” or “remote wireless device”) 107 may perform a radio resource control (RRC) procedure with a cellular base station 102 via another wireless device (“second wireless device” or “relay wireless device”) 106. The remote wireless device may be any of various types of wireless devices capable of indirectly performing wireless communication with the cellular base station via an intermediate relay wireless device. As an option, the remote wireless device may be an accessory device, such as a smartwatch or other wearable device configured as a low-cost and / or low-power wireless device. The relay wireless device may be any of various types of wireless devices capable of supporting wireless communication between the remote wireless device and the cellular base station by acting as an intermediate relay wireless device. As an option, the relay wireless device may be a smartphone capable of acting as a companion device to the remote wireless device. Many other types of wireless devices may also serve as remote wireless devices and / or relay wireless devices. The cellular base station may be any of various types of base stations capable of indirectly performing wireless communication with the remote wireless device via an intermediate relay wireless device and capable of providing access to the cellular network. As an option, the cellular base station may be a 3GPP 5G NR gNB. Alternatively (or otherwise), cellular base stations may be able to operate according to any of a variety of other possible cellular communication standards.

[0092] The RRC procedure may include any of a variety of RRC procedures. At least according to some implementations, the RRC procedure may be used to attempt to establish an RRC connection between a remote wireless device and a cellular base station. For example, the remote wireless device may attempt to perform an RRC connection procedure, an RRC reconstruction procedure, or an RRC recovery procedure. As another possibility, the RRC procedure may be used to reconfigure an existing RRC connection between the remote wireless device and the cellular base station (e.g., the cellular base station may attempt to perform an RRC reconfiguration procedure) or to release an existing RRC connection between the remote wireless device and the cellular base station (e.g., the cellular base station may attempt to perform an RRC release procedure).

[0093] To perform an RRC (Redirect RRC) procedure, a relay radio device can relay RRC messages between a remote radio device and a cellular base station. For example, to perform an RRC connection procedure, the remote radio device can transmit an RRC connection request to the relay radio device, which in turn can transmit the RRC connection request to the cellular base station on behalf of the remote radio device. In response to the RRC connection request, the cellular base station can transmit an RRC setup message, configured to facilitate the RRC connection setup with the remote radio device, to the relay radio device. The relay radio device can then transmit the RRC setup message to the remote radio device on behalf of the cellular base station, including, for example, configuration information for establishing the RRC connection. The remote radio device can also transmit an RRC setup complete message to the relay radio device, which can then transmit the RRC setup complete message to the cellular base station on behalf of the remote radio device.

[0094] It should be noted that the RRC messages relayed by the relay radio device between the remote radio device and the cellular base station may differ for different RRC procedures. According to some implementations, some or all of the RRC message content may be relayed completely by the relay radio device. Alternatively, some or all of the RRC message content may not be relayed, and / or additional information may be added to some or all of the relayed RRC messages. For example, in some cases, the configuration information used to establish a remote RRC connection may include information used by the relay radio device to establish one or more relay signaling radio bearers between the relay radio device and the cellular base station, information that the remote radio device may not need to establish a remote RRC connection.

[0095] As another possibility, when a relay radio device provides an RRC message to a cellular base station on behalf of a remote radio device, it can provide the cellular base station with identification information associated with the remote radio device, such as indicating to the cellular base station that the RRC message is provided on behalf of the remote radio device. Similarly, when a relay radio device provides an RRC message to a relay radio device on behalf of a remote radio device, the cellular base station can provide the relay radio device with identification information associated with the remote radio device, such as indicating to the relay radio device that it is providing the RRC message on behalf of the remote radio device. In some cases, providing such identification information can be used to distinguish between RRC messages related to an RRC connection between the relay radio device and the cellular base station and RRC messages related to an RRC connection between the remote radio device and the cellular base station. This distinction is also possible by using a different signaling radio bearer for relay RRC messages than for RRC messages related to an RRC connection between the relay radio device and the cellular base station. If the relay radio device is configured to relay RRC messages between a cellular base station and each of a plurality of remote radio devices, providing such identification information can also be used to identify which RRC messages are associated with which RRC connections; for example, in this case, each RRC message relayed between the cellular base station and the corresponding remote radio device may include remote radio device identification information for the corresponding remote radio device.

[0096] According to at least some implementations, the relay radio device may transmit a discovery broadcast message (e.g., event-driven or periodically triggered) indicating that the relay radio device supports relay RRC messages. The remote radio device may receive the discovery broadcast message from the relay radio device (and possibly from one or more other radio devices capable of supporting relay RRC messages). The remote radio device may perform link selection to determine the radio link on which to attempt to establish a relay RRC connection with the cellular base station, and may select the relay radio device at least in part based on the discovery broadcast message received from the relay radio device. The remote radio device may attempt to perform the RRC procedure with the cellular base station via the relay radio device at least in part based on the link selection.

[0097] Since a remote RRC connection may rely on multiple radio links (e.g., a radio link between the remote wireless device and the relay wireless device, and a radio link between the relay wireless device and the cellular base station), it may be beneficial to provide techniques for handling radio link interruptions. According to some implementations, one or both of the remote wireless device or the relay wireless device may utilize a response timer to help determine whether a link failure has occurred in the radio link between the remote wireless device and the relay wireless device. For example, the relay wireless device may start a response validity timer based at least in part on relaying a Radio Resource Control message to the remote wireless device, and may stop the response validity timer when a response is received from the remote wireless device. If the response validity timer expires without receiving a response, the relay wireless device may determine that a link failure has occurred in the radio link between the relay wireless device and the remote wireless device. If the relay wireless device determines that a link failure has occurred in the radio link between the relay wireless device and the remote wireless device, for example, in this manner or in any of a variety of other ways, the relay wireless device may provide an indication of the link failure of the radio link between the relay wireless device and the remote wireless device to the cellular base station. In at least some cases, a relay wireless device can receive an indication from a cellular base station to release the remote wireless device in response to an indication of a link failure in the wireless link between the relay wireless device and the remote wireless device.

[0098] In some implementations, the remote wireless device may initiate a response protection timer at least in part based on providing a radio resource control message to the relay wireless device, and may stop the response protection timer when a response to the radio resource control message is received from the relay wireless device. If the response protection timer expires without receiving a response, the remote wireless device may determine that a link failure has occurred in the wireless link between the remote wireless device and the relay wireless device. In this case, the remote wireless device may perform link selection to determine the radio resource control connection on which it attempts to establish a relay with the cellular base station, for example, based at least in part on the link failure of the wireless link between the remote wireless device and the relay wireless device.

[0099] According to some implementations, acknowledgment can typically be provided in response to an RRC message transmitted as part of a remote RRC procedure (e.g., the relay signaling radio bearer used may be configured to acknowledged mode or AM). Based on such acknowledgment (or its absence) and / or in any of a variety of other ways, the relay radio device can also determine whether a link failure has occurred in the radio link between the relay radio device and the cellular base station. If such a link failure is detected, the relay radio device can provide an indication of the link failure to the remote radio device. This indication may include any of the following explicit indications: a link failure has occurred in the radio link between the relay radio device and the cellular base station, an indication to suspend the radio link between the relay radio device and the remote radio device, or an indication to release the radio link between the relay radio device and the remote radio device. Based on the indication (e.g., if an indication to release the radio link between the first and second radio devices is received), the remote radio device can perform link selection to re-determine the radio resource control connection on which it is attempting to establish a relay with the cellular base station. Alternatively (e.g., if an instruction to suspend the radio link between the relay radio device and the remote radio device is received), the remote radio device may wait for a specific period of time before performing link selection, for example, in the case where the relay radio device is able to re-establish the radio link with the cellular network and resume relaying RRC messages with the cellular network on behalf of the remote radio device.

[0100] Therefore, using the techniques described herein, a remote wireless device may establish and manage an RRC connection to a cellular network via a relay wireless device, and the remote wireless device, the relay wireless device, and the cellular network may handle potential link failures of the wireless link used to support the remote RRC connection. At least according to some implementations, such techniques can be used to support cellular communication for a wider range of wireless devices, potentially helping to expand the range of possible wireless devices that can further utilize cellular communication to achieve low-cost and / or low-power wireless devices.

[0101] Figures 6 to 23 and additional information

[0102] Provided Figures 6 to 23 And the additional information below, which illustrates the relevant Figure 5 Further considerations and possible specific implementation details of the method are provided, and are not intended to limit this disclosure in general. Various variations and alternatives to the details provided below are possible and should be considered to fall within the scope of this disclosure.

[0103] 3GPP 5G NR cellular communication technologies are being developed for a variety of applications, including enhanced mobile broadband (eMBB), ultra-reliable low-latency communication (URLLC), and massive machine-type communication (mMTC). mMTC use cases can include the widespread deployment of wireless devices designed to have relatively low cost and / or low power consumption. Such devices can include any of wearable devices, equipment, process control equipment, measurement equipment, and / or a variety of other types of devices. In at least some implementations (e.g., in some cases, wearable devices), it is possible that such devices are typically located relatively close to another wireless device (e.g., in some cases, a smartphone) that can be used as a relay for communicating with the cellular network. Therefore, in at least some implementations, it is advantageous to support UE-to-NW communication relay frameworks, for example, to help support the operation of low-cost and / or low-power wireless devices that can benefit from such frameworks. For example, Figure 6 An aspect of a possible exemplary wireless communication relay between a remote UE 602, a relay UE 604, and a cellular base station 606 is illustrated. As shown, in the illustrated scenario, the remote UE 602 can communicate with the cellular base station 606 via a relay link between the remote UE 606 and the relay UE 602, and via a Uu link between the relay UE 604 and the cellular base station 604.

[0104] Depending on the implementation scheme, several possible types of UE-to-NW relay frameworks may exist. As one possibility, at least in some cases, Layer 3 relay, which can be implemented without affecting the access layer communication layer, can be used. As another possibility, Layer 2 relay can be used, for example, by establishing and maintaining a terminated radio resource control connection between the remote UE and the cellular base station. Figures 7 to 8 An exemplary aspect of a possible protocol stack architecture for user plane and control plane communication in a 3GPP-based UE-to-network relay framework is shown according to some implementations, wherein the communication relay is implemented at layer 2.

[0105] More specifically, Figure 7 A user plane radio protocol stack for a Layer 2 UE-to-network relay is illustrated. This network relay utilizes the PC5 interface between the remote UE 702 and the relay UE 704 to provide a communication link between the remote UE 702 and the eNB 706, and provides a communication link to the core network 708 that provides access to the eNB 706. Similarly, Figure 8A control plane radio protocol stack for a Layer 2 UE-to-network relay is illustrated. This network relay utilizes the PC5 interface between the remote UE 802 and the relay UE 804 to provide a communication link between the remote UE 802 and the eNB 806, and provides a communication link to the core network 808 that provides access to the eNB 806. As shown, the relay can operate above the RLC sublayer. The Uu PDCP and RRC links can be terminated between the remote UE and the eNB, while the RLC, MAC, and PHY, as well as non-3GPP transport layers, are terminated in each link (e.g., the link between the remote UE and the relay UE, and the link between the relay UE and the eNB).

[0106] Currently, RRC connection procedures can be performed between a UE and the network via a direct connection on the Uu interface, for example, according to 3GPP-based cellular communication. For RRC connection procedures between remote UEs, where the peer RRC entity is terminated at both the remote UE and the network, RRC message transmission can be relayed via a relay UE. This allows for an additional relay link between the relay UE and the remote UE, in addition to the Uu link between the relay UE and the network. Since the Uu link and the relay link can be maintained independently, a remote RRC procedure may fail due to an interruption of either the relay link or the Uu link. Therefore, carefully designing the RRC procedure framework to support the ability of remote UEs to perform RRC procedures may be important.

[0107] According to some implementation schemes, RRC message delivery by a remote UE via a Uu link can be performed via a relay signaling radio bearer (SRB) established between the network and the relay UE. The network may be able to establish one or more relay SRBs. It is possible that all relay SRBs are configured in Radio Link Control (RLC) Acknowledged Mode (AM). When using multiple relay SRBs, different relay SRBs can be used for different types of signaling. For example, as a possibility, relay SRB0 can be used for 3GPP SRB0 transmission, relay SRB1 for 3GPP SRB1 transmission, and relay SRB2 for 3GPP SRB2 transmission. Note that other configurations are also possible. A relay SRB may be common to all remote UEs that have established a relay link with a given relay UE. It is possible that each RRC message from a remote UE is transmitted along with a remote UE identifier, for example, to distinguish RRC messages from different remote UEs within a single relay SRB.

[0108] As previously described, link failure detection can be an important consideration for supporting remote RRC procedures. For bidirectional RRC procedures (e.g., expecting a response for each message in the RRC procedure), the relay UE may be able to utilize a response validity timer to control RRC response messages from the remote UE via the relay link. For example, the relay UE may start the response validity timer when sending an RRC message to the remote UE and stop the timer when the relay UE receives the expected RRC response from the remote UE. When the timer expires (e.g., if an RRC response is received from the remote UE while the timer is running), the relay UE can determine that the RRC message transmitted via the relay link has failed.

[0109] For each possible RRC procedure, if the relay UE can detect that an RRC message transmission failure has occurred (e.g., in a trunk link or Uu link), the relay UE can take action in response to the RRC message transmission failure. For example, in the case of a trunk link failure, the relay UE can notify the network of the trunk link failure. In the case of a Uu link failure, the relay UE can provide information to the remote UE based on the Uu link failure, which can facilitate the remote UE in performing link reselection. For example, as one possibility, the relay UE can send an indication of Uu link failure to the remote UE. As another possibility, the relay UE can send an indication to suspend the trunk link to all remote UEs with which it has established a trunk link. As yet another possibility, the relay UE can directly close the trunk link with the remote UE (e.g., without explicitly indicating that a Uu link failure has occurred).

[0110] Figures 9 to 14 This is a signal flow diagram that shows further details of various possible remote RRC procedures. Figure 9 Various aspects of an exemplary scenario according to some implementations are illustrated, in which multiple remote UEs attempt to establish RRC connections with a gNB via the same relay UE. In the exemplary scenario, RRC message delivery for remote UEs in a Uu link can be performed on a relay SRB established between the relay UE and the network.

[0111] As shown in the figure, in the illustrated scenario, at 910, relay UE 906 can establish an RRC connection with gNB 908, potentially including establishing a relay SRB configuration. This may include establishing a network for relay SRB1 for remote UE SRB0 transmissions and relay SRB2 for remote UE SRB1 and SRB2 transmissions. At 912, first remote UE 902 can provide an RRC connection request to relay UE 906. At 914, relay UE 906 can provide a connection request to gNB 908 on behalf of first remote UE 902, including, for example, identification information for first remote UE 902. The connection request can be provided using relay SRB1, for example, because it can relay SRB0 transmissions from first remote UE 902. At 916, second remote UE 904 can provide an RRC connection request to relay UE 906. In 918, relay UE 906 may provide a connection request to gNB 908 on behalf of the second remote UE 904, including, for example, identification information for the second remote UE 904. The connection request may be provided using relay SRB1, for example, because it may relay SRB0 transmissions from the first remote UE 902.

[0112] In 920, gNB 908 may provide relay UE 906 with an RRC setup message intended for use with a first remote UE 902. The RRC setup message intended for use with the first remote UE 902 may include identification information for the first remote UE 902. In 922, relay UE 906 may provide an RRC setup message to the first remote UE 902 on behalf of gNB 908. Similarly, in 924, gNB 908 may provide relay UE 906 with an RRC setup message intended for use with a second remote UE 904. The RRC setup message intended for use with the second remote UE 904 may include identification information for the second remote UE 904. In 926, relay UE 906 may provide an RRC setup message to the second remote UE 904 on behalf of gNB 908. Note that relay SRB1 may be used again for both RRC setup messages provided by gNB 908.

[0113] In 928, the first remote UE 902 can provide an RRC setup complete message to the relay UE 906. In 930, the relay UE 906 can provide an RRC setup complete message to the gNB 908 on behalf of the first remote UE 902, including, for example, identification information for the first remote UE 902. The RRC setup complete message can be provided using relay SRB2, for example, because it can relay SRB1 transmissions from the first remote UE 902. In 932, the second remote UE 904 can provide an RRC setup complete message to the relay UE 906. In 934, the relay UE 906 can provide an RRC setup complete message to the gNB 908 on behalf of the second remote UE 904, including, for example, identification information for the second remote UE 904. The RRC setup complete message can be provided using relay SRB2, for example, because it can relay SRB1 transmissions from the second remote UE 904. Note that different types of remote UE identification information may be used for different SRBs. For example, for SRB0 transmissions, remote UE identification information can be assigned by the relay UE, while for SRB1 transmissions, remote UE identification may include complete or partial Cell Radio Network Temporary Identifier (CRNTI) information.

[0114] Figure 10An exemplary scenario according to some implementations is illustrated, in which a single remote UE attempts to establish an RRC connection with a gNB via a relay UE. As shown, in the illustrated scenario, in 1008, remote UE 1002 may provide an RRC connection request to relay UE 1004. In 1010, remote UE 1002 and relay UE 1004 may be connected. In 1012, relay UE 1004 may use a relay SRB to provide an RRC connection request to gNB 1006 and indicate the identification information of remote UE 1002. In 1014, gNB 1006 may use a relay SRB to provide an RRC connection establishment message to relay UE 1004. The RRC connection setup message may include the C RNTI information of the remote UE 1002, as well as any of the following: relay link configuration information, bearer configuration information, Uu data radio bearer configuration information, mapping configuration information, and / or various information supporting the establishment of a remote RRC connection between gNB 1006 and the remote UE 1002. In 1016, the relay UE 1004 may provide the RRC connection setup message to the remote UE 1002, including at least some information received from gNB 1006, such as any information required by the remote UE 1002 as part of establishing a remote RRC connection between gNB 1006 and the remote UE 1002 (e.g., relay link configuration information, bearer configuration information). In 1018, the remote UE 1002 may connect to gNB 1006. In 1020, remote UE 1002 can establish an RRC connection with gNB 1006 by providing an RRC setup complete message to relay UE 1004. In 1022, relay UE 1004 can use a relay SRB to provide an RRC setup complete message to gNB 1006 and indicate the identification information of remote UE 1002. In 1024, gNB 1006 can also connect to remote UE 1002.

[0115] Figure 11An exemplary scenario according to some implementations is illustrated, in which a single remote UE attempts to re-establish an RRC connection with a gNB via a relay UE. As shown, in the illustrated scenario, in 1108, remote UE 1102 and relay UE 1104 can be connected. In 1110, remote UE 1102 can provide an RRC re-establishment request to relay UE 1104. In 1112, relay UE 1104 can use a relay SRB to provide an RRC re-establishment request to gNB 1106 and indicate the identification information of remote UE 1102. In 1114, gNB 1106 can use a relay SRB to provide an RRC re-establishment message to relay UE 1104. The RRC re-establishment message may include CRNTI information of the remote UE 1102, as well as any of the following: relay link configuration information, bearer configuration information, Uu data radio bearer configuration information, mapping configuration information, and / or various information supporting the re-establishment of the remote RRC connection between gNB 1106 and the remote UE 1102. In 1116, the relay UE 1004 may provide the RRC re-establishment message to the remote UE 1102, including at least some information received from gNB 1106, such as any information required by the remote UE 1102 as part of the re-establishment of the remote RRC connection between gNB 1106 and the remote UE 1102 (e.g., relay link configuration information, bearer configuration information). In 1118, the remote UE 1102 may connect to gNB 1106. In 1120, remote UE 1102 can re-establish its RRC connection with gNB 1106 by providing an RRC re-establishment completion message to relay UE 1104. In 1122, relay UE 1104 can use its relay SRB to provide an RRC re-establishment completion message to gNB 1106 and indicate the identification information of remote UE 1102. In 1124, gNB 1106 can also connect to remote UE 1102.

[0116] Figure 12An exemplary scenario according to some implementations is illustrated, in which a single remote UE attempts to restore an RRC connection with a gNB via a relay UE. As shown, in the illustrated scenario, in 1208, remote UE 1202 can provide an RRC restoration request to relay UE 1204. In 1210, remote UE 1202 and relay UE 1204 can be connected. In 1212, relay UE 1204 can provide an RRC restoration request to gNB 1206 using a relay SRB and indicate the identification information of remote UE 1202. In 1214, gNB 1206 can provide an RRC restoration message to relay UE 1204 using a relay SRB. The RRC recovery message may include the CNNTI information of the remote UE 1202, as well as any of the following: relay link configuration information, bearer configuration information, Uu data radio bearer configuration information, mapping configuration information, and / or various information supporting the restoration of the remote RRC connection between gNB 1206 and remote UE 1202. In 1216, the relay UE 1204 may provide the RRC recovery message to the remote UE 1202, including at least some information received from gNB 1206, such as any information required by the remote UE 1202 as part of restoring the remote RRC connection between gNB 1206 and remote UE 1202 (e.g., relay link configuration information, bearer configuration information). In 1218, the remote UE 1202 may connect to gNB 1206. In 1220, remote UE 1202 can complete the RRC recovery process with gNB 1206 by providing an RRC recovery completion message to relay UE 1204. In 1222, relay UE 1204 can use a relay SRB to provide an RRC recovery completion message to gNB 1206 and indicate the identification information of remote UE 1202. In 1224, gNB 1206 can also connect to remote UE 1202.

[0117] Figure 13An exemplary scenario according to some implementations is illustrated, in which a gNB releases a remote RRC connection with a remote UE via a relay UE; as shown, in the illustrated scenario, at 1308, remote UE 1302 and relay UE 1304 are each connected to each other and have an RRC connection with gNB 1306. At 1310, gNB 1306 can provide an RRC release message to relay UE 1304 using a relay SRB. The RRC release message may include identification information of remote UE 1302, and any of the following: relay link configuration information, bearer configuration information, Uu data radio bearer configuration information, mapping configuration information, and / or various information supporting the release of the remote RRC connection between gNB 1306 and remote UE 1302. In 1312, the relay UE 1304 may provide an RRC release message to the remote UE 1302, including at least some information received from the gNB 1306, such as any information required by the remote UE 1302 as part of releasing the remote RRC connection between the gNB 1306 and the remote UE 1302 (e.g., relay link configuration information, bearer configuration information). In 1314, the remote UE 1302 may enter an idle mode due to the release of the remote RRC connection. It should be noted that, as an alternative, at least according to some implementations, the remote UE 1302 may be released to an inactive mode.

[0118] Figure 14An exemplary scenario according to some implementations is illustrated, in which the gNB reconfigures a remote RRC connection with a remote UE via a relay UE; as shown, in the illustrated scenario, at 1408, the remote UE 1402 and the relay UE 1404 are each connected to each other and have an RRC connection with the gNB 1406. At 1410, the gNB 1406 can provide an RRC reconfiguration message to the relay UE 1404 using a relay SRB. The RRC reconfiguration message may include identification information of the remote UE 1402, as well as relay link configuration information, bearer configuration information, Uu data radio bearer configuration information, mapping configuration information, and / or any of various information supporting the reconfiguration of the remote RRC connection between the gNB 1406 and the remote UE 1402. In 1412, the relay UE 1404 may provide the remote UE 1402 with an RRC reconfiguration message, including at least some information received from the gNB 1406, such as any information required by the remote UE 1402 as part of reconfiguring the remote RRC connection between the gNB 1406 and the remote UE 1402 (e.g., relay link configuration information, bearer configuration information). In 1414, the remote UE 1402 may provide the relay UE 1404 with an RRC reconfiguration complete message, and in 1416, the relay UE 1404 may use the relay SRB to provide the RRC reconfiguration complete message to the gNB 1406 and indicate the identification information of the remote UE 1402.

[0119] In addition to providing a framework for relaying RRC messages between a remote UE and a gNB, a framework for detecting and handling link failures in conjunction with remote RRC connections can also be provided. One aspect of this framework is that the relay SRB might be configured with Radio Link Control (RLC) Acknowledgment Mode (AM). Therefore, if the remote UE's RRC message transmission fails due to a link failure between the relay UE and the network, the relay UE can detect the RLC failure and trigger a Radio Link Failure (RLF). In a Uu link, the relay UE can perform an RRC connection reconstruction procedure or a Secondary Cell Group (SCG) failure recovery procedure. Relative to the relay link, the relay UE can send a Uu link failure indication to the remote UE, or send a pause relay link indication to the remote UE (and possibly any other remote UEs connected to the relay UE), or directly shut down the relay link.

[0120] A remote UE can perform link reselection based on a Uu link failure. For example, if the ongoing procedure is for establishment / re-establishment / recovery, the remote UE can retry the procedure on the newly selected link. If the ongoing switching is for another procedure such as reconfiguration, the remote UE can perform a re-establishment procedure on the newly selected link if Access Stratum (AS) security is activated. Otherwise, if AS security is not activated, the UE can perform an RRC connection establishment procedure on the newly selected link. It should be noted that if the remote UE's RRC message transmission fails while the network is transmitting to the relay UE, the network may be able to reconfigure the relay SRB and retransmit the message.

[0121] Figures 15 to 17 This is a signal flow diagram illustrating aspects of various possible scenarios where the RRC process between a remote UE and a gNB fails due to a link failure between the relay UE and the gNB, according to various implementation schemes.

[0122] Specifically, Figure 15Some aspects of an exemplary scenario according to some implementations are illustrated, where remote RRC connection establishment fails due to a link failure between the relay UE and the gNB. As shown in the illustrated scenario, in 1508, remote UE 1502 can provide an RRC connection request to relay UE 1504. In 1510, remote UE 1502 and relay UE 1504 can be connected. In 1512, relay UE 1504 can provide an RRC connection request to gNB 1506 using a relay SRB and indicate the identification information of remote UE 1502. In 1514, gNB 1506 can provide an RRC connection establishment message to relay UE 1504 using a relay SRB. In 1516, relay UE 1504 can provide an RRC connection setup message to remote UE 1502. In 1518, remote UE 1502 can connect to gNB 1506. In step 1520, remote UE 1502 may attempt to establish an RRC connection with gNB 1506 by providing an RRC setup complete message to relay UE 1504. In step 1522, relay UE 1504 may use a relay SRB to provide an RRC setup complete message to gNB 1506 and indicate the identification information of remote UE 1502. However, RRC setup complete message delivery may fail, and in step 1524, relay UE 1504 may declare a Uu link RLF. In step 1526, relay UE 1504 may stop providing discovery broadcasts, and in step 1528, it may provide an indication to remote UE 1502 to suspend the relay link between remote UE 1502 and relay UE 1504. In step 1530, remote UE 1502 may enter idle mode. In step 1532, relay UE 1504 and gNB 1506 may perform an RRC connection re-establishment procedure. In 1534, remote UE 1502 can perform link reselection. In 1536, relay UE 1504 can resume providing discovery broadcasts. In 1538, remote UE 1502 can, for example, transmit a new RRC connection request to relay UE 1504 or possibly to another radio device, depending on the result of the link selection.

[0123] Figure 16Some aspects of an exemplary scenario according to some implementations are illustrated, in which remote RRC connection re-establishment fails due to a link failure between the relay UE and the gNB. As shown, in the illustrated scenario, in 1608, remote UE 1602 can provide an RRC re-establishment request to relay UE 1604. In 1610, remote UE 1602 and relay UE 1604 can be connected. In 1612, relay UE 1604 can provide an RRC re-establishment request to gNB 1606 using the relay SRB and indicate the identification information of remote UE 1602. However, the delivery of the RRC re-establishment request may fail, and in 1614, relay UE 1604 can declare a Uu link RLF. In 1616, relay UE 1604 can stop providing discovery broadcasts, and in 1618, an indication that a Uu failure has occurred can be provided to remote UE 1602. In step 1620, relay UE 1604 and gNB 1606 can perform the RRC connection re-establishment procedure. In step 1622, remote UE 1602 can perform link reselection. In step 1624, relay UE 1604 can resume providing discovery broadcasts. In step 1626, remote UE 1602 can, for example, transmit a new RRC re-establishment request to relay UE 1604 or possibly to another radio device, depending on the link selection result.

[0124] Figure 17This is a signal flow diagram illustrating aspects of an exemplary scenario according to some implementations, where a remote RRC connection recovery failure occurs due to a link failure between the relay UE and the gNB. As shown, in the illustrated scenario, in 1708, the remote UE 1702 can provide an RRC recovery request to the relay UE 1704. In 1710, the remote UE 1702 and the relay UE 1704 can be connected. In 1712, the relay UE 1704 can use the relay SRB to provide an RRC recovery request to the gNB 1706 and indicate the identification information of the remote UE 1702. In 1714, the gNB 1706 can use the relay SRB to provide an RRC recovery message to the relay UE 1704. In 1716, the relay UE 1704 can provide the RRC recovery message to the remote UE 1702. In 1718, the remote UE 1702 can connect to the gNB 1706. In 1720, remote UE 1702 may attempt to complete the RRC recovery process with gNB 1706 by providing an RRC recovery complete message to relay UE 1704. In 1722, relay UE 1704 may use a relay SRB to provide an RRC recovery complete message to gNB 1706 and indicate the identification information of remote UE 1702. However, RRC recovery complete message delivery may fail, and in 1724, relay UE 1704 may declare a Uu link RLF. In 1726, relay UE 1704 may stop providing discovery broadcasts, and in 1728, it may provide an indication to remote UE 1702 to suspend the relay link between remote UE 1702 and relay UE 1704. In 1730, remote UE 1702 may enter inactive mode. In 1732, relay UE 1704 and gNB 1706 may perform an RRC connection re-establishment process. In 1734, remote UE 1702 can perform link reselection. In 1736, relay UE 1704 can resume providing discovery broadcasts. In 1738, remote UE 1702 can, for example, transmit a new RRC recovery request to relay UE 1704 or possibly to another radio device, depending on the result of the link selection.

[0125] Besides detecting Uu link failures, providing relay link failure detection and handling techniques may also be useful. As such, for bidirectional RRC procedures (e.g., where RRC messages are provided in both the uplink and downlink), the relay UE might be able to rely on a validity timer to control RRC response messages from the remote UE via the relay link. For example, Figure 18An exemplary scenario according to some implementations is illustrated, in which a relay UE uses a response validity timer to detect link failure between the relay UE and a remote UE; as shown, in the illustrated scenario, in 1808, a connection may be initially established between the remote UE 1802 and the relay UE 1804. In 1810, the gNB 1806 may provide an RRC reconfiguration message to the relay UE 1804 using a relay SRB. The RRC reconfiguration message may include identification information of the remote UE 1802. In 1812, the relay UE 1804 may provide an RRC reconfiguration message to the remote UE 1802, including at least some information received from the gNB 1806. In 1814, when an RRC message is sent to the remote UE 1802, the relay UE 1804 may start a response validity timer. Note that the relay UE 1804 may stop the timer when a response is received from the remote UE 1802. In version 1816, remote UE 1802 can transmit an RRC reconfiguration complete message to relay UE 1804, but relay UE 1804 may not receive this message. In version 1818, the response validity timer may expire, and relay UE 1804 may consider that an RRC message transmission failure has occurred on the relay link. It should be noted that this response validity timer can be configured by relay UE 1804 itself, or by gNB 1806, for example, within the RRC message.

[0126] Figure 19 This is a signal flow diagram illustrating an aspect of an exemplary scenario according to some implementations, in which a relay UE uses a response validity timer to detect a PC5 interface failure between the relay UE and the remote UE. Figure 19 The scenario can be similar to at least some of the scenarios. Figure 18In most scenarios, but more specifically, the PC5 RRC message validity timer can be used to detect trunk link failures when the PC5 interface is used for a trunk link between a remote and a trunk device. As shown in the diagram, in the illustrated scenario, in 1908, a connection can be initially established between the remote UE 1902 and the trunk UE 1904. In 1910, the gNB 1906 can provide an RRC reconfiguration message to the trunk UE 1904, which may include instructions for configuring the PC5 message validity timer. In 1912, the trunk UE 1904 can provide a PC5 reconfiguration message to the remote UE 1902. In 1914, when the PC5 reconfiguration message is sent to the remote UE 1902, the trunk UE 1904 can start the response validity timer. Note that the trunk UE 1904 can stop the timer when a response is received from the remote UE 1902. In 1916, remote UE 1902 can transmit a PC5 reconfiguration complete message to relay UE 1904, but relay UE 1904 may not receive this message. In 1918, the response validity timer may expire, and relay UE 1904 can assume that a relay link failure has occurred. Note that this PC5 RRC message validity timer can be configured by relay UE 1904 itself or by gNB 1906, for example, in the RRC message, as shown in the figure. Also note that, in a general sense, this method can be used to detect link failure of either UE when the two UEs are equivalent UEs performing sidelink communication. Furthermore, note that this method can be used in conjunction with any of various PC5 RRC messages, such as PC5 reconfiguration (e.g., as shown in the figure), UE capability requests, and / or any of various other possible messages.

[0127] In at least some cases, similar methods of using response timers to detect trunk link failures can also be used by the remote UE, or alternatively. For example, for bidirectional RRC procedures, the remote UE can also rely on validity timers to control RRC response messages from the trunk UE via the trunk link. Figure 20An exemplary scenario according to some implementations is illustrated, in which the remote UE uses a response protection timer in response to a link failure between the remote UE and the relay UE. As shown, in the illustrated scenario, in 2008, gNB 2006 may indicate the protection timer duration to relay UE 2004, which relay UE 2002 may broadcast the protection timer duration as part of discovery (e.g., as a configuration parameter) or as part of connection establishment to the remote UE. In 2010, relay UE 2004 may be connected, while in 2012, remote UE 2002 may be inactive. In 2014, remote UE 2002 may provide an RRC recovery request to relay UE 2004, and in 2016, a response protection timer may be started, which may be stopped after remote UE 2002 receives a response from relay UE 2004. However, the RRC recovery request delivery may fail, so in 2018, the response protection timer may expire, and a relay link transmission failure is detected. In 2020, remote UE 2002 can detect trunk link failure based on trunk link transmission failure. In 2022, remote UE 2002 can perform link selection, and in 2024, it can transmit an RRC recovery request to attempt to restore the RRC connection with gNB 2006, possibly to trunk UE 2004, or possibly to another radio device, for example, based on the result of link selection. It should be noted that the trunk UE can reuse the current RRC timer (e.g., t319) as a protection timer for the remote UE, or the gNB can configure a different expiration duration for the remote UE (e.g., as in the illustrated scenario), or the trunk UE can autonomously configure the protection timer duration among various possibilities for determining the protection timer duration.

[0128] When the relay UE detects a relay link failure, for example using... Figures 18 to 19 In the illustrated scenario, using a timer-based method, or any of various other possible methods (e.g., RLC failure-based, radio link failure detection based on radio link monitoring, etc.), the relay UE can notify the network of a relay link failure according to at least some implementation schemes. In this scenario, the network may be able to immediately terminate the current RRC procedure with the remote UE, and the relay UE can, for example, delete the remote UE by itself or according to network configuration.

[0129] Figures 21 to 23 This is a signaling flow diagram illustrating link failure handling aspects of various exemplary scenarios according to some implementation schemes, where the remote RRC procedure fails due to a link failure between the relay UE and the remote UE.

[0130] More specifically, Figure 21This is a signal flow diagram illustrating an aspect of an exemplary scenario according to some implementations, where remote RRC connection establishment fails due to a link failure between the relay UE and the remote UE. As shown, in the illustrated scenario, in 2108, the remote UE 2102 can provide an RRC connection request to the relay UE 2104. In 2110, the remote UE 2102 and the relay UE 2104 can be connected. In 2112, the relay UE 2104 can use the relay SRB to provide an RRC connection request to the gNB 2106 and indicate the identification information of the remote UE 2102. In 2114, the gNB 2106 can use the relay SRB to provide an RRC connection establishment message to the relay UE 2104. In 2116, the relay UE 2104 can provide an RRC connection setup message to the remote UE 2102. In 2118, the remote UE 2102 can connect to the gNB 2106. In 2120, remote UE 2102 can attempt to establish an RRC connection with gNB 2106 by providing an RRC setup complete message to relay UE 2104. However, the delivery of the RRC setup complete message may fail, and in 2122, remote UE 2102 can detect a relay link failure. In 2124, remote UE 2102 can perform link selection, and in 2126, it can trigger an attempt to re-establish the RRC connection using the newly selected link. In 2128, relay UE 2104 can also detect a relay link failure. In 2130, relay UE 2104 can provide gNB 2106 with a remote UE relay link transmission failure indication, which may indicate the identification information of remote UE 2102. In 2132, gNB 2106 can terminate the connection establishment process, and in 2134, it can provide relay UE 2104 with a remote UE removal message, including indication of the identification information for remote UE 2102.

[0131] Figure 22Some aspects of an exemplary scenario according to some implementations are illustrated, in which remote RRC connection re-establishment fails due to a link failure between the relay UE and the remote UE. As shown in the illustrated scenario, in 2208, the remote UE 2202 can provide an RRC re-establishment request to the relay UE 2204. In 2210, the remote UE 2202 and the relay UE 2204 can be connected. In 2212, the relay UE 2204 can provide an RRC re-establishment request to the gNB 2206 using the relay SRB and indicate the identification information of the remote UE 2202. In 2214, the gNB 2206 can provide an RRC re-establishment message to the relay UE 2204 using the relay SRB. In 2216, the relay UE 2204 can provide an RRC re-establishment message to the remote UE 2202. However, the delivery of the RRC re-establishment message may fail, and in 2218, the relay UE 2204 can detect a relay link failure. In 2220, relay UE 2204 can provide an indication (e.g., as an optimal action) to release the relay link to remote UE 2202. In 2222, remote UE 2202 can perform link selection, and in 2224, an attempt can be triggered to re-establish the RRC connection using the newly selected link. In 2226, relay UE 2204 can provide gNB 2206 with a remote UE relay link transmission failure indication, which can indicate the identification information of remote UE 2202. In 2228, gNB 2206 can terminate the re-establishment process, and in 2230, a remote UE removal message can be provided to relay UE 2204, including an indication of the identification information for remote UE 2202.

[0132] Figure 23Some aspects of an exemplary scenario according to some implementations are illustrated, in which a remote RRC connection recovery failure occurs due to a link failure between a relay UE and a remote UE. As shown in the illustrated scenario, in 2308, the remote UE 2302 can provide an RRC recovery request to the relay UE 2304. In 2310, the remote UE 2302 and the relay UE 2304 can be connected. In 2312, the relay UE 2304 can use a relay SRB to provide an RRC recovery request to the gNB 2306 and indicate the identification information of the remote UE 2302. In 2314, the gNB 2306 can use a relay SRB to provide an RRC recovery message to the relay UE 2304. In 2316, the relay UE 2304 can provide an RRC recovery message to the remote UE 2302. In 2318, the remote UE 2302 can connect to the gNB 2306. In 2320, remote UE 2302 can attempt to complete the RRC recovery process using gNB 2304 by providing an RRC recovery completion message to relay UE 2306. However, RRC recovery message delivery may fail, and in 2322, remote UE 2302 can detect a relay link failure. In 2324, remote UE 2302 can perform link selection, and in 2326, it can trigger an attempt to re-establish the RRC connection using the newly selected link. In 2328, relay UE 2304 can also detect a relay link failure. In 2330, relay UE 2304 can provide gNB 2306 with a remote UE relay link transmission failure indication, which may indicate the identification information of remote UE 2302. In 2332, gNB 2306 can terminate the recovery process, and in 2334, it can provide relay UE 2304 with a remote UE removal message, including indication of the identification information for remote UE 2302.

[0133] Further exemplary implementations are provided below.

[0134] One set of embodiments may include an apparatus comprising: a processor configured to cause a relay wireless device to: establish a radio resource control connection with a cellular base station; receive a radio resource control connection request from a remote wireless device; and relay radio resource control messages between the remote wireless device and the cellular base station.

[0135] According to some implementations, the processor is also configured to cause the relay wireless device to: transmit a discovery broadcast message indicating that the relay wireless device supports relay radio resource control messages; wherein at least in part, a radio resource control connection request is received from a remote wireless device in response to the discovery broadcast message.

[0136] According to some implementations, the processor is also configured to enable the relay wireless device to: detect a link failure of the wireless link between the relay wireless device and the cellular base station; and provide an indication of the link failure of the wireless link between the relay wireless device and the cellular base station to a remote wireless device.

[0137] According to some implementation schemes, an indication of link failure of the wireless link between the relay wireless device and the cellular base station includes one or more of the following: an indication that the wireless link between the relay wireless device and the cellular base station has failed; an indication to suspend the wireless link between the relay wireless device and the remote wireless device; or an indication to release the wireless link between the relay wireless device and the remote wireless device.

[0138] According to some implementations, the processor is further configured to cause the relay wireless device to stop providing discovery broadcast messages to remote wireless devices, at least in part, based on the failure of the wireless link between the relay wireless device and the cellular base station.

[0139] According to some implementations, the processor is further configured to enable the relay wireless device to: detect a link failure of the wireless link between the relay wireless device and the remote wireless device; and provide an indication of the link failure of the wireless link between the relay wireless device and the remote wireless device to the cellular base station.

[0140] According to some implementations, the processor is further configured to cause the relay wireless device to: receive an indication of releasing the remote wireless device from the cellular base station in response to an indication of link failure of the wireless link between the relay wireless device and the remote wireless device.

[0141] According to some implementations, the processor is further configured to cause the relay wireless device to: initiate a response validity timer at least in part based on relaying radio resource control messages to the remote wireless device; and detect link failure of the wireless link between the relay wireless device and the remote wireless device based on the expiration of the response validity timer.

[0142] According to some implementations, the processor is further configured to enable the relay wireless device to relay radio resource control messages between the cellular base station and each of a plurality of remote wireless devices, wherein each radio resource control message relayed between the cellular base station and the corresponding remote wireless device includes remote wireless device identification information for the corresponding remote wireless device.

[0143] Another set of embodiments may include a cellular base station, comprising: an antenna; a radio component operatively coupled to the antenna; and a processor operatively coupled to the radio component; wherein the cellular base station is configured to: receive a radio resource control message from a relay radio device, wherein the radio resource control message includes information relayed from a remote radio device to the cellular base station by the relay radio device; and transmit the radio resource control message to the relay radio device, wherein the radio resource control message includes information configured to be relayed from the relay radio device to a remote radio device.

[0144] According to some implementation schemes, radio resource control messages include radio resource control connection establishment requests, wherein radio resource control messages include radio resource control connection setup messages.

[0145] According to some implementation schemes, radio resource control messages include radio resource control connection re-establishment requests, wherein radio resource control messages include radio resource control re-establishment messages.

[0146] According to some implementation schemes, radio resource control messages include radio resource control connection restoration requests, wherein radio resource control messages include radio resource control restoration messages.

[0147] According to some implementation schemes, the cellular base station is further configured to transmit a radio resource control release message to a relay radio device, wherein the radio resource control release message is configured to be relayed by the relay radio device to a remote radio device.

[0148] According to some implementation schemes, the cellular base station is further configured to transmit a radio resource control reconfiguration message to a relay radio device, wherein the radio resource control reconfiguration message is configured to be relayed by the relay radio device to a remote radio device.

[0149] Another set of embodiments may include a method comprising: a first wireless device providing a first radio resource control message to a second wireless device, wherein the first radio resource control message includes information configured to be relayed by the second wireless device to a cellular base station; and receiving a second radio resource control message from the second wireless device, wherein the second radio resource control message includes information relayed by the second wireless device from the cellular base station to the first wireless device.

[0150] According to some implementations, the method further includes: performing link selection to determine a radio resource control connection to be attempted to be established with a cellular base station relay, wherein a first radio resource control message is provided to a second wireless device based at least in part on the link selection.

[0151] According to some implementations, the method further includes: initiating a response protection timer based at least in part on providing a radio resource control message to a second wireless device, wherein the response protection timer is stopped when a response to the resource control message is received from the second wireless device; determining, at least in part, that a link failure of the wireless link between the first and second wireless devices has occurred based on the expiration of the response protection timer; and performing link selection based at least in part on the link failure of the wireless link between the first and second wireless devices to determine the wireless link on which a radio resource control connection attempting to establish a relay with a cellular base station is sought.

[0152] According to some implementations, the method further includes: receiving an instruction to release a wireless link between a first wireless device and a second wireless device, and performing link selection based at least in part on the instruction to release the wireless link between the first wireless device and the second wireless device to determine a wireless link on which a radio resource control connection is attempted to be established with a cellular base station for relaying.

[0153] According to some implementation schemes, the first radio resource control message includes one of the following: a radio resource control connection establishment request; a radio resource control connection re-establishment request; or a radio resource control connection restoration request.

[0154] Another exemplary implementation may include a method comprising: a wireless device performing any or all of the foregoing examples.

[0155] Another exemplary embodiment may include a wireless device comprising: an antenna; a radio component coupled to the antenna; and a processing element operatively coupled to the radio component, wherein the device is configured to implement any or all of the foregoing examples.

[0156] Another exemplary embodiment may include an apparatus comprising a processing element configured to cause a wireless device to implement any or all of the foregoing examples.

[0157] Another set of exemplary embodiments may include a non-transitory computer-accessible memory medium comprising program instructions that, when executed at the device, cause the device to implement any or all of the portions of any of the foregoing examples.

[0158] Another exemplary set of implementations may include a computer program comprising instructions for performing any or all portions of any of the examples described above.

[0159] Another exemplary set of embodiments may include an apparatus that includes means for performing any or all elements of any of the examples described above.

[0160] As is widely recognized, the use of personally identifiable information should comply with privacy policies and practices that are generally accepted to meet or exceed industry or governmental requirements for protecting user privacy. Specifically, personally identifiable information data should be managed and processed to minimize the risk of unintentional or unauthorized access or use, and the nature of authorized use should be clearly explained to users.

[0161] In addition to the exemplary embodiments described above, further embodiments of this disclosure may be implemented in any of a variety of forms. For example, some embodiments may be implemented as computer-implemented methods, computer-readable storage media, or computer systems. Other embodiments may be implemented using one or more custom-designed hardware devices such as ASICs. Other embodiments may be implemented using one or more programmable hardware elements such as FPGAs.

[0162] In some embodiments, a non-transitory computer-readable storage medium may be configured to store program instructions and / or data, wherein if the program instructions are executed by a computer system, the computer system performs a method, such as any method embodiment of the method embodiments described herein, or any combination of the method embodiments described herein, or any subset or combination of any such subset of any method embodiments described herein.

[0163] In some embodiments, the apparatus (e.g., UE 106 or 107) may be configured to include a processor (or a set of processors) and a memory medium, wherein the memory medium stores program instructions, and the processor is configured to read from the memory medium and execute the program instructions, wherein the program instructions are executable to implement any of the various method embodiments described herein (or any combination of method embodiments described herein, or any subset of any method embodiments described herein, or any combination of such subsets). The apparatus may be implemented in any of a variety of forms.

[0164] 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 invention is intended that the following claims be interpreted to encompass all such variations and modifications.

Claims

1. A method for wireless communication, comprising: By relay wireless equipment: Receive corresponding Radio Resource Control (RRC) connection requests from multiple remote wireless devices; as well as RRC messages are relayed between the cellular base station and each of the plurality of remote wireless devices to establish an RRC connection with the cellular base station. The RRC messages include a corresponding RRC setup completion message. Each RRC setup complete message is relayed between the corresponding remote wireless device and the cellular base station in the plurality of remote wireless devices on the Uu link between the relay wireless device and the cellular base station, and is transmitted on the Uu link together with the corresponding remote wireless device identifier in order to distinguish the corresponding RRC setup complete messages of different remote wireless devices.

2. The method according to claim 1, further comprising: Transmit a discovery broadcast message, the discovery broadcast message indicating that the relay wireless device supports relay RRC messages; Specifically, at least in part, an RRC connection request is received from the plurality of remote wireless devices in response to the discovery broadcast message.

3. The method according to claim 1, further comprising: The wireless link between the relay wireless device and the cellular base station was detected to have failed. as well as Provide the plurality of remote wireless devices with an indication of link failure of the wireless link between the relay wireless device and the cellular base station.

4. The method of claim 3, wherein the indication of a link failure of the wireless link between the relay wireless device and the cellular base station includes one or more of the following: An indication has been received that a link failure has occurred in the wireless link between the relay wireless device and the cellular base station; An instruction to suspend the wireless link between the relay wireless device and at least one of the plurality of remote wireless devices; or An instruction to release the wireless link between the relay wireless device and at least one of the plurality of remote wireless devices.

5. The method according to claim 3, further comprising: At least in part, due to a link failure in the wireless link between the relay wireless device and the cellular base station, the transmission of discovery broadcast messages to the remote wireless device is stopped.

6. The method according to claim 1, further comprising: The wireless link between the relay wireless device and the first remote wireless device among the plurality of remote wireless devices is detected to be faulty; as well as The cellular base station is provided with an indication of a link failure in the wireless link between the relay wireless device and the first remote wireless device.

7. The method according to claim 6, further comprising: In response to an indication of a link failure in the wireless link between the relay wireless device and the first remote wireless device, an indication to release the first remote wireless device from the cellular base station is received.

8. An apparatus for wireless communication, comprising: Processor, the processor being configured to enable the relay wireless device to: Receive corresponding Radio Resource Control (RRC) connection requests from multiple remote wireless devices; as well as RRC messages are relayed between the cellular base station and each of the plurality of remote wireless devices to establish an RRC connection with the cellular base station. The RRC messages include a corresponding RRC setup completion message. Each RRC setup complete message is relayed between the corresponding remote wireless device and the cellular base station in the plurality of remote wireless devices on the Uu link between the relay wireless device and the cellular base station, and is transmitted on the Uu link together with the corresponding remote wireless device identifier in order to distinguish the corresponding RRC setup complete messages of different remote wireless devices.

9. The apparatus of claim 8, wherein the processor is further configured to cause the relay wireless device to: Transmit a discovery broadcast message, the discovery broadcast message indicating that the relay wireless device supports relay RRC messages; in, At least in part, RRC connection requests are received from the plurality of remote wireless devices in response to the discovery broadcast message.

10. The apparatus of claim 8, wherein the processor is further configured to cause the relay wireless device to: Detecting link failure in the wireless link between the relay wireless device and the cellular base station; and Provide the plurality of remote wireless devices with an indication of link failure of the wireless link between the relay wireless device and the cellular base station.

11. The apparatus of claim 10, wherein the indication of a link failure of the wireless link between the relay wireless device and the cellular base station includes one or more of the following: An indication has been received that a link failure has occurred in the wireless link between the relay wireless device and the cellular base station; An instruction to suspend the wireless link between the relay wireless device and at least one of the plurality of remote wireless devices; or An instruction to release the wireless link between the relay wireless device and at least one of the plurality of remote wireless devices.

12. The apparatus of claim 10, wherein the processor is further configured to cause the relay wireless device to: At least in part, based on the link failure of the wireless link between the relay wireless device and the cellular base station, the transmission of discovery broadcast messages to the remote wireless device is stopped.

13. The apparatus of claim 8, wherein the processor is further configured to cause the relay wireless device to: The system detects a link failure in the wireless link between the relay wireless device and the first remote wireless device among the plurality of remote wireless devices; and The cellular base station is provided with an indication of a link failure in the wireless link between the relay wireless device and the first remote wireless device.

14. The apparatus of claim 13, wherein the processor is further configured to cause the relay wireless device to: In response to an indication of a link failure in the wireless link between the relay wireless device and the first remote wireless device, an indication to release the first remote wireless device from the cellular base station is received.

15. A relay wireless device, comprising: Radio components; and One or more processors, operatively coupled to the radio component, wherein the one or more processors are configured to cause the relay wireless device to: Relaying multiple radio resource control messages between a cellular base station and each of the multiple remote wireless devices. Each radio resource control message is relayed on the Uu link between the corresponding remote radio device and the cellular base station among the plurality of remote radio devices, and is transmitted on the Uu link together with the corresponding remote radio device identifier in order to distinguish the corresponding radio resource control messages of different remote radio devices.

16. The relay wireless device of claim 15, wherein the one or more processors are further configured to cause the relay wireless device to: Transmit a discovery broadcast message, the discovery broadcast message indicating that the relay wireless device supports relay RRC messages; in, The relaying of the plurality of radio resource control messages between the cellular base station and each of the plurality of remote wireless devices is based at least in part on the response to the discovery broadcast message.

17. The relay wireless device of claim 15, wherein the one or more processors are further configured to cause the relay wireless device to: Detecting link failure in the wireless link between the relay wireless device and the cellular base station; and Provide the plurality of remote wireless devices with an indication of link failure of the wireless link between the relay wireless device and the cellular base station.

18. The relay wireless device of claim 17, wherein the indication of a link failure of the wireless link between the relay wireless device and the cellular base station includes one or more of the following: An indication has been received that a link failure has occurred in the wireless link between the relay wireless device and the cellular base station; An instruction to suspend the wireless link between the relay wireless device and at least one of the plurality of remote wireless devices; or An instruction to release the wireless link between the relay wireless device and at least one of the plurality of remote wireless devices.

19. The relay wireless device of claim 17, wherein the one or more processors are further configured to cause the relay wireless device to: The transmission of discovery broadcast messages to remote wireless devices is stopped, at least in part, due to a link failure in the wireless link between the relay wireless device and the cellular base station.

20. The relay wireless device of claim 15, wherein the one or more processors are further configured to cause the relay wireless device to: Detecting a link failure in the wireless link between the relay wireless device and the first remote wireless device among the plurality of remote wireless devices; and The cellular base station is provided with an indication of a link failure in the wireless link between the relay wireless device and the first remote wireless device.

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