Link selection for idle or inactive user equipment

Abstract

A remote user equipment (UE) configured to access a network via one of a direct link with a base station or a relay link with a relay UE performs a method, the method comprising: receiving a link selection criterion, the link selection criterion being configured by the network; identifying that the relay UE is available for pre-camping; selecting the relay UE based on the link selection criterion; pre-camping on the relay link corresponding to the relay UE; and initiating a network access procedure via the relay link.

Description

Background Art

[0001] A user equipment (UE) may establish a connection with at least one of a plurality of networks or network types. In some scenarios, the UE may communicate with the network using a direct communication link to a base station of the corresponding network. In other scenarios, the UE may communicate with the network using a UE-to-network relay. For example, a UE may establish a direct communication link with another UE that is camped on a base station of the corresponding network. In this type of arrangement, data and information sent by a UE to the network may initially be transmitted to another UE, and then relayed to the base station on behalf of the UE by the other UE. For downlink communications intended for a UE, data and information may initially be sent to another UE, and then relayed to the UE by the other UE on behalf of the network.

[0002] The network may configure the UE to utilize criteria for link selection. For example, the UE may initially search for a base station and / or another UE to camp on. The UE may detect multiple base stations and relay UEs available for camping. The UE may then select one of the multiple base stations and relay UEs based on the link selection criteria. The UE may then attempt to access the network via the selected base station or another UE. Summary of the invention

[0003] Some exemplary embodiments include a method performed by a remote user equipment (UE), the remote UE being configured to access a network via one of a direct link with a base station or a relay link with a relay UE. The method includes: receiving a link selection criterion, the link selection criterion being configured by the network; identifying that the relay UE is available for pre-camping; selecting the relay UE based on the link selection criterion; pre-camping on the relay link corresponding to the relay UE; and initiating a network access procedure via the relay link.

[0004] Other exemplary embodiments include a remote user equipment (UE) comprising a transceiver configured to access a network via one of a direct link with a base station or a relay link with a relay UE. The UE also includes a processor configured to perform operations including: receiving link selection criteria, the link selection criteria being configured by the network; identifying that the relay UE is available for pre-camping; selecting the relay UE based on the link selection criteria; pre-camping on the relay link corresponding to the relay UE; and initiating a network access procedure via the relay link.

[0005] Yet another exemplary embodiment includes an integrated circuit comprising: a circuit system configured to receive a link selection criterion, the link selection criterion being configured by a network; a circuit system configured to identify a relay UE available for pre-camping; a circuit system configured to select the relay UE based on the link selection criterion; a circuit system configured to cause a user equipment (UE) to pre-camp on a relay link corresponding to the relay UE; and a circuit system configured to initiate a network access procedure via the relay link. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] Figure 1 Exemplary network arrangements are shown according to various exemplary embodiments.

[0007] Figure 2 An exemplary UE according to various exemplary embodiments is shown.

[0008] Figure 3 Methods for link selection according to various exemplary embodiments are shown.

[0009] Figures 4a to 4d Each illustrates an exemplary scenario related to a remote UE camping on a selected link.

[0010] Figure 5a to Figure 5b Each shows an exemplary signaling diagram related to an authentication procedure for camping on a relay link.

[0011] Figure 6 Methods for selecting a link based on link selection criteria according to various exemplary embodiments are shown.

[0012] Figure 7 A signaling diagram related to when a remote UE may initiate link selection is shown.

[0013] Figure 8 A signaling diagram related to when a remote UE may initiate link selection is shown. DETAILED DESCRIPTION

[0014] The exemplary embodiments may be further understood with reference to the following description and the associated drawings, wherein similar elements have the same reference numerals. The exemplary embodiments describe devices, systems, and methods for implementing various link selection mechanisms. As will be described below, link selection generally refers to selecting a communication link to be used for direct or indirect communication with a network.

[0015] The exemplary embodiments are described with respect to UE. However, the use of UE is provided for illustration purposes only. The exemplary embodiments may be used with any electronic component configured with hardware, software and / or firmware for exchanging information (e.g., control information) and / or data with a network. Therefore, the UE described herein is used to represent any suitable electronic device.

[0016] In order to perform the full range of functionality generally available to a UE via a network connection, the UE may communicate directly or indirectly with a base station of the corresponding network. The UE may communicate directly with the currently occupied base station. The UE may communicate indirectly with the base station using a UE-to-network relay. For example, a UE may be configured with a direct communication link to another UE, and the other UE may occupy a base station. In this type of arrangement, the other UE may act as a relay for the UE. Therefore, data and information sent by the UE to the network may initially be transmitted to another UE, and then relayed to the base station by the other UE on behalf of the UE. For downlink communications intended for a UE, data and information may initially be sent to another UE, and then relayed to the UE by the other UE on behalf of the network.

[0017] An exemplary embodiment may characterize the UE-to-network relay as a layer 2 (L2) relay. From a protocol stack perspective, the L2 relay may include one or more layers between a UE and another UE, one or more layers between a UE and a base station, one or more layers between a UE and a core network, one or more layers between another UE and a base station, and one or more layers between a base station and a core network. However, those skilled in the art will appreciate that the exemplary embodiments are not limited to L2 relays and may also be applicable to layer 3 (L3) relays or any other suitable type of relay. Therefore, throughout this specification, the term "UE-to-network relay" may represent any suitable configuration in which an electronic component (e.g., another UE) operates as a relay between a UE and a base station.

[0018] Exemplary embodiments relate to link selection. Throughout this specification, the term "link selection" generally refers to selecting a communication link that a UE is to use to access a network. The UE may perform various operations during the link selection procedure, such as, but not limited to, searching for a base station or another UE to pre-empt, collecting measurement data, selecting a communication link, attempting to access the network, etc. However, the criteria utilized by the UE during the link selection procedure may be configured by the network. Throughout this specification, references to a network performing an operation may refer to operations performed at a base station, a radio access network (RAN), a core network, a network function, a network service backbone, a network server, any other type of network component, or any combination thereof.

[0019] In order to distinguish between UEs, reference will be made to "remote UE" and "relay UE". The term "remote UE" may be used to identify a UE that will operate as a remote endpoint from a base station. The remote UE may be directly connected to the base station or communicate indirectly with the base station using a UE-to-network relay. Throughout this specification, the terms "UE" and "remote UE" may be used interchangeably. The term "relay UE" may be used to identify a UE that may act as a relay for a remote UE. The term "relay UE" is not intended to indicate that a relay UE is actively acting as a relay. Rather, the term relay UE indicates that the UE has the ability to operate as a relay for a remote UE. In addition, a relay UE may also be configured to act as a remote UE at the same time. Throughout this specification, the terms "UE", "another UE" and "relay UE" may be used interchangeably. However, any reference to a remote UE and a relay UE is for illustrative purposes only, and different networks may refer to similar concepts by different names.

[0020] An exemplary embodiment relates to a remote UE operating in a radio resource control (RRC) idle state or an RRC inactive state. When the remote UE is in the RRC idle state or the RRC inactive state, the remote UE may perform link selection. RRC refers to the radio resource control (RRC) protocol. Those skilled in the art will appreciate that when the remote UE is in the RRC idle state, the remote UE is not exchanging data with the network, and within the network, radio resources are not being allocated to the remote UE. However, when the remote UE is operating in the RRC idle state, the remote UE may listen to transmissions from the network and / or relay UEs. Those skilled in the art will also appreciate that when the remote UE is in the RRC inactive state, the remote UE is in a low power mode and is not exchanging data with the network. When the remote UE is in the RRC inactive state, the remote UE may still listen to transmissions from the network and / or relay UEs. The difference between the RRC idle state and the RRC inactive state is that when the remote UE is in the RRC inactive state, context information may be saved at the remote UE / network, and procedures may be available that enable the remote UE to transition between the RRC inactive state and the RRC connected state faster than the remote UE to transition between the RRC idle state and the RRC connected state.

[0021] As described above, exemplary embodiments relate to link selection. Some exemplary scenarios described below may involve a remote UE determining whether to camp on a relay UE or a base station, the remote UE determining whether to attempt to access a network via a base station or via a relay UE, and when the attempt to access the network is unsuccessful, the remote UE selecting a different communication link. As described above, link management may include various operations performed by the remote UE. However, the criteria used by the remote UE during link selection may be configured by the network.

[0022] Figure 1An exemplary network arrangement 100 according to various exemplary embodiments is shown. The exemplary network arrangement 100 includes UEs 110, 112. Those skilled in the art will appreciate that UEs 110, 112 may be any type of electronic component configured to communicate via a network, such as a mobile phone, a tablet, a smart phone, a tablet phone, an embedded device, a wearable device, an Internet of Things (IoT) device, a massive machine type communication (mMTC) device, etc. It should also be appreciated that a practical network arrangement may include any number of UEs used by any number of users. Therefore, an example with two UEs 110, 112 is provided for illustration purposes only.

[0023] UE 110, 112 can communicate directly with one or more networks. In the example of network configuration 100, the networks with which UE 110, 112 can wirelessly communicate are 5G New Radio (NR) Radio Access Network (5G NR-RAN) 120, LTE Radio Access Network (LTE-RAN) 122, and Wireless Local Area Network (WLAN) 124. However, UE 110, 112 can also communicate with other types of networks, and UE 110, 112 can also communicate with the network through a wired connection. Therefore, UE 110, 112 may include a 5G NR chipset that communicates with 5G NR-RAN 120, an LTE chipset that communicates with LTE-RAN 122, and an ISM chipset that communicates with WLAN 124.

[0024] 5G NR-RAN 120 and LTE-RAN 122 may be part of a cellular network that may be deployed by a cellular provider (e.g., Verizon, AT&T, Sprint, T-Mobile, etc.). These networks 120, 122 may include, for example, cells or base stations (NodeB, eNodeB, HeNB, eNBS, gNB, gNodeB, macrocell base station, microcell base station, small cell base station, femtocell base station, etc.) configured to send and receive traffic from a UE equipped with an appropriate cellular chipset. In this example, 5G NR-RAN 120 is shown with gNB 120A and gNB 120B, and LTE-RAN 122 is shown with eNB 122A. However, in an actual system arrangement, any appropriate number of cells and base stations may be deployed. WLAN 124 may include any type of wireless local area network (WiFi, hotspot, IEEE 802.11x network, etc.).

[0025] The base station (e.g., gNB 120A, gNB 120B, eNB 122A) may include one or more communication interfaces to exchange data and / or information with the occupied UE, the corresponding RAN, the cellular core network 130, the Internet 140, etc. In addition, the base station may include a processor configured to perform various operations. For example, the processor of the base station may be configured to perform operations related to link selection. However, reference to the processor is for illustrative purposes only. The operation of the base station may also be represented as an independent combined component of the base station, or may be a modular component coupled to the base station, such as an integrated circuit with or without firmware. For example, an integrated circuit may include an input circuit for receiving a signal and a processing circuit for processing the signal and other information. In addition, in some base stations, the functionality of the processor is shared between two or more processors such as a baseband processor and an application processor. The exemplary embodiment may be implemented in any of these or other configurations of the base station.

[0026] Those skilled in the art will appreciate that any associated process may be performed for the UE 110, 112 to connect to the 5G NR-RAN 120 and the LTE-RAN 122. For example, as discussed above, the 5G NR-RAN 120 and the LTE-RAN 122 may be associated with a particular cellular provider at which the UE 110, 112 and / or its user has a contract and credential information (e.g., stored on a SIM card). Upon detecting the presence of the 5G NR-RAN 120, the UE 110, 112 may transmit the corresponding credential information in order to associate with the 5G NR-RAN 120. More specifically, the UE 110, 112 may be associated with a particular base station (e.g., gNB 120A of the 5G NR-RAN 120, gNB 120B of the 5G NR-RAN 120, eNB 122A of the LTE-RAN 122).

[0027] UE 110, 112 may also communicate indirectly with one or more networks using UE-to-network relay. For example, UE 110 may be a remote UE and UE 112 may be a relay UE. In this example, UE 112 may camp on gNB 120A of 5G NR-RAN 120, and UE 110 may camp on UE 112. Uplink communications from UE 110 may initially be transmitted to UE 112 over the communication link. Subsequently, UE 112 may relay the communications to gNB 120A on behalf of UE 110. Downlink communications from gNB 120A to UE 110 may initially be sent to UE 112. Subsequently, UE 112 may relay the communications to UE 110 on behalf of gNB 120A. Those skilled in the art will appreciate that in this example, gNB 120A, 5G NR-RAN 120 and / or core network 130 may manage the communication link between UE 110 and UE 112.

[0028] Throughout this specification, UE 110 may be referred to as a remote UE, and UE 112 may be referred to as a relay UE. However, this is for exemplary purposes only and is not intended to limit the exemplary embodiments in any way.

[0029] In addition to the networks 120, 122, and 124, the network arrangement 100 includes a cellular core network 130, the Internet 140, an IP multimedia subsystem (IMS) 150, and a network service backbone 160. The cellular core network 130 can be viewed as an interconnected collection of components that manage the operation and traffic of the cellular network. The cellular core network 130 also manages the traffic flowing between the cellular network and the Internet 140. The IMS 150 can be generally described as an architecture for delivering multimedia services to the UE 110 using the IP protocol. The IMS 150 can communicate with the cellular core network 130 and the Internet 140 to provide multimedia services to the UE 110. The network service backbone 160 communicates directly or indirectly with the Internet 140 and the cellular core network 130. The network service backbone 160 can be generally described as a set of components (e.g., servers, network storage arrangements, etc.) that implement a set of services that can be used to extend the functionality of the UE 110 to communicate with various networks.

[0030] Figure 2 An exemplary UE 110 is shown according to various exemplary embodiments. Figure 1100 is used to describe the UE 110. The UE 110 may include a processor 205, a memory arrangement 210, a display device 215, an input / output (I / O) device 220, a transceiver 225, and other components 230. The other components 230 may include, for example, a SIM card, an audio input device, an audio output device, a power supply, a data acquisition device, a port for electrically connecting the UE 110 to other electronic devices, etc. Those skilled in the art will understand that the UE 110 may represent any electronic component capable of operating as a remote UE and / or a relay UE.

[0031] The processor 205 may be configured to execute a plurality of engines of the UE 110. For example, the engines may include a link selection engine 235. The link selection engine 235 may perform various operations related to link selection, including but not limited to managing link selection criteria received from a network, collecting measurement data, selecting a link for pre-camping, and selecting a link for network access.

[0032] The above engines are each an application (e.g., a program) executed by the processor 205 for exemplary purposes only. The functions associated with the engine may also be represented as an independently integrated component of the UE 110, or may be a modular component coupled to the UE 110, such as an integrated circuit with or without firmware. For example, an integrated circuit may include an input circuit for receiving a signal and a processing circuit for processing the signal and other information. The engine may also be embodied as an application or multiple separate applications. In addition, in some UEs, the functionality described for the processor 205 is shared between two or more processors such as a baseband processor and an application processor. The exemplary embodiments may be implemented in any of these or other configurations of the UE.

[0033] The memory arrangement 210 may be a hardware component configured to store data related to operations performed by the UE 110. The display device 215 may be a hardware component configured to display data to a user, and the I / O device 220 may be a hardware component that enables user input. The display device 215 and the I / O device 220 may be separate components or may be integrated together (such as a touch screen). The transceiver 225 may be a hardware component configured to establish a connection with the 5G NR-RAN 120, LTE-RAN 122, WLAN 124, UE 112, etc. Thus, the transceiver 225 may operate on multiple different frequencies or channels (e.g., a continuous set of frequencies).

[0034] UE 110 may be configured to be in one of a plurality of different operating states. One operating state may be characterized as an RRC connected state, another operating state may be characterized as an RRC idle state, and another operating state may be characterized as an RRC inactive state. It will be appreciated by those skilled in the art that when UE 110 is in an RRC connected state, UE 110 may exchange information and / or data with a network. The exchange of information and / or data may enable UE 110 to perform functionality available via a network connection. It will also be appreciated by those skilled in the art that when UE 110 is in an RRC idle state, UE 110 is not exchanging data with a network, and within the network, radio resources are not being allocated to UE 110. However, when UE 110 is in an RRC idle state, UE 110 may listen to transmissions from a network or a relay UE. As with the RRC idle state, when UE 110 is in the RRC inactive state, UE 110 is not exchanging data with the network, however, UE 110 may still listen to transmissions from the network or relay UEs. The difference between the RRC idle state and the RRC inactive state is that for the RRC inactive state, some context information may be saved at UE 110 / network, and procedures may be available that make the transition between the RRC inactive state and the RRC connected state for UE 110 faster than the transition between the RRC idle state and the RRC connected state for a remote UE.

[0035] When deployed within a network, UE 110 may transition between operating states. For example, UE 110 may camp on a base station or relay UE of a corresponding network and experience connection problems. Subsequently, UE 110 may transition from an RRC connected state or an RRC inactive state to an RRC idle state. At this point, UE 110 still camps on a base station, but is now in an RRC idle state. When UE 110 is in an RRC idle state, UE 110 may not be able to exchange data with the network. In order to exchange data with the network, UE 110 may transition from an RRC idle state to an RRC connected state. Specifically, when in an RRC idle state, UE 110 may listen to information such as, but not limited to, the following: a primary synchronization signal (PSS) and a secondary synchronization signal (SSS), a master information block (MIB), a broadcast message, a system information block (SIB), a paging notification, and the like. In response, UE 110 may send a request to the network indicating that UE 110 wishes to be moved to an RRC connected state. A successful transition from the RRC idle state to the RRC connected state may include message exchanges between UE 110 and a base station (directly or indirectly via a UE-to-network relay). In the RRC connected state, a network context may be established between the network and UE 110. Thus, UE 110 may be allocated radio resources, and UE 110 may be able to exchange data with the network.

[0036] When UE 110 is in the RRC connected state, UE 110 may transition to the RRC inactive state. As described above, the RRC inactive state is a low power mode and is not used to exchange data with the network. However, the context is stored at UE 110 / network, which will enable UE 110 to quickly transition back to the RRC connected state. The scenario described above is intended only to provide a general example of UE 110 transitioning between the RRC connected state, the RRC idle state, and the RRC inactive state. The exemplary embodiments described below relate to UE 110 performing link selection when operating in the RRC idle state or the RRC inactive state.

[0037] As described above, the remote UE 110 may camp on a base station (e.g., gNB 120A, gNB 120B) or a relay UE (e.g., UE 112). Those skilled in the art will appreciate that the interface between the 5G NR-RAN 120 and the UE 110 may be referred to as a Uu interface. Throughout this specification, a direct communication link between a UE and a base station of the 5G NR-RAN 120 may be referred to as a "Uu link". In addition, the term "relay link" may refer to a communication link with a relay UE that may be used by a remote UE to communicate indirectly with a network.

[0038] Figure 3 A method 300 for link selection is shown according to various exemplary embodiments. Figure 1 The network layout of 100 and Figure 2 The method 300 is described with reference to the UE 110 of FIG.

[0039] In 305, the remote UE 110 receives the link selection criteria. The link selection criteria may include various rules for link selection. The exemplary embodiments are described with reference to the link selection criteria being configured on the network side and then provided to the remote UE 110. However, the exemplary embodiments are not limited to configuring the link selection criteria on the network side. The exemplary embodiments may be applied to scenarios where the link selection criteria are configured by the UE itself or by a source external to the network (e.g., a manufacturer, software developer, user, etc.).

[0040] When the link selection criteria are configured on the network side, the link selection criteria may be provided in any of a number of different ways to the remote UE 110. For example, the link selection criteria may be included in an RRC procedure, transmitted to the remote UE 110 over a dedicated communication link, included in a broadcast, included in a configuration message, included in a software update, included in a carrier setup, included in a Tracking Area Update (TAU) procedure, included in a Routing Area Update (RAU) procedure, or may be provided to the remote UE 110 in any other suitable manner.

[0041] The remote UE 110 may store the link selection criteria in the memory arrangement 210. Thus, the link selection criteria provided by the network need not be provided to the remote UE 110 each time the remote UE 110 is configured to perform link selection. Instead, the network may pre-configure the remote UE 110 with the link selection criteria so that the link selection criteria may be used even when the remote UE 110 is out of coverage.

[0042] The link selection criteria may include any of a variety of different rules. For example, the link selection criteria may include rules related to quality criteria, link-based priority, service-based priority, device type priority, and allowed relay UEs.

[0043] The quality criteria may relate to the quality of the potential communication link. For example, the quality criteria may include a threshold value related to the link quality. If the measurement data meets the quality threshold value, the remote UE may camp on the corresponding base station or relay UE. The threshold value may be applicable to the link type, one or more frequency bands, one or more base stations, and one or more relay UEs. Thus, the remote UE 110 may be configured with multiple threshold values ​​and reference a specific threshold value when the remote UE is relevant to the current scenario.

[0044] The link-based priorities may indicate whether the remote UE 110 is to prioritize a certain type of link (e.g., Uu links over relay links or relay links over Uu links). The remote UE 110 may be configured to always prioritize a certain link type, or the remote UE 110 may be configured to prioritize Uu links over relay links under a first set of conditions and prioritize relay links over Uu links under a second set of conditions.

[0045] The service-based priority may indicate whether the remote UE 110 is to prioritize a link based on the type of service that the link can provide (e.g., voice, data, etc.). The remote UE 110 may be configured to always prioritize a certain type of service, or the remote UE 110 may be configured to prioritize a first one or more types of services under a first set of conditions and a second one or more types of services under a second set of conditions.

[0046] The device type priority may relate to the type of remote UE 110 to utilize the link selection criteria. For example, a wearable type remote UE and a smart phone type remote UE may each be configured with different link selection criteria. Thus, a first type of UE may be configured to perform link selection in a first manner, and a second type of UE may be configured to perform link selection in a second manner.

[0047] The link selection criteria may also indicate that the remote UE 110 is allowed to camp on certain relay UEs. For example, the link selection criteria may include one or more relayIDs, each of which identifies a specific relay UE. If a releyID is provided to the remote UE 110, the remote UE 110 may be allowed to camp on the relay UE associated with the relayID. If the releyID is not provided to the remote UE 110, the remote UE 110 may not be allowed to camp on the relay UE. Alternatively, if the relayID is not provided, the remote UE may request to connect to the relay UE or attempt to authenticate with the relay UE. Therefore, camping on a relay link may be based on an authentication procedure in which the relay UE and / or the network allows the remote UE 110 to camp on the relay link. Refer to the following Figure 5a to Figure 5b An example of an authentication procedure is described.

[0048] In 310, the remote UE 110 collects measurement data corresponding to one or more base stations and / or one or more relay UEs. The measurement data may indicate to the remote UE 110 whether the corresponding base station or relay UE is suitable for pre-occupation. For example, when the remote UE 110 is in an idle state or an inactive state, the remote UE 110 may tune its transceiver 225 to various frequency bands to search for base stations and relay UEs that the remote UE 110 can pre-occupy. The remote UE 110 may collect measurement data for any detected base station and / or relay UE. For a base station, the remote UE 110 may collect measurement data corresponding to a Uu interface. For a relay UE, the remote UE 110 may collect measurement data corresponding to a relay link. The measurement data may relate to layer 1 (L1), layer 3 (L3), or any other appropriate aspect of wireless communication. When the remote UE 110 is in an idle state or an inactive state, the remote UE 110 may be configured to periodically collect the measurement data according to a schedule or a timer. The remote UE 110 may also be configured to collect the measurement data based on the occurrence of predetermined conditions.

[0049] In 315, the remote UE 110 selects a link to camp on based on the link selection criteria. For example, the remote UE 110 may apply the link selection criteria to a set of suitable base stations and relay UEs detected in 310. Thus, the remote UE 110 may camp on a relay link of a relay UE, camp on a Uu link of a base station, or camp on both a relay link and a Uu link. As will be described below, the remote UE 110 may attempt to access the network on the camped link. Figure 6 Method 600 of UE 110 describes an example of how remote UE 110 may utilize link selection criteria to select a link.

[0050] Figures 4a to 4d Each illustrates an exemplary scenario related to remote UE 110 camping on a selected link. Figure 4aA scenario 400 is shown in which a remote UE 110 is camping on a gNB 120A. While camping on gNB 120A, the remote UE 110 may receive paging information and system information from gNB 120A via a Uu link. In this arrangement, the remote UE 110 may also attempt to access the network via the Uu link with gNB 120A.

[0051] Figure 4b A scenario 410 is shown in which remote UE 110 is camping on relay UE 112. While camping on relay UE 112, remote UE 110 may receive paging information and system information from the network via the relay link with relay UE 112. In this arrangement, remote UE 110 may also attempt to access the network via the relay link with relay UE 112.

[0052] Figure 4c A scenario 420 is shown in which remote UE 110 is camping on both gNB 120A and relay UE 112. In this arrangement, remote UE 110 may decide whether to utilize gNB 120A or relay UE 112 to obtain paging information and system information. Remote UE 110 may make this determination on any appropriate basis. Remote UE 110 may utilize the selected one of gNB 120A and relay UE 112 to attempt to access the network.

[0053] Figure 4d Scenario 430 is shown in which remote UE 110 is within coverage area 432 of gNB 120A but not within coverage area 434 of gNB 120B. In scenario 430, relay UE 112 is within coverage area 410 of gNB 120B. In this type of arrangement, remote UE 110 may select the Uu link of gNB 120A for camping. Remote UE 110 may also select the relay link of relay UE 112 for camping. Thus, UE-to-network relay may enable remote UE 110 to communicate with a base station even when remote UE 110 is not within the coverage area of ​​the base station.

[0054] In scenario 430, remote UE 110 may select one of a Uu link with gNB 120A or a relay link with relay UE 112 for pre-camping. To provide an example, if the link selection criteria indicate that the Uu link will take precedence over the relay link, the remote UE 110 may be configured to select only relay UEs within the coverage area of ​​the same base station for pre-camping. Therefore, in this example, remote UE 110 may not select relay UE 112 for pre-camping. To provide another example, if the link selection criteria indicate that the relay link will take precedence over the Uu link, the remote UE 110 may be configured to pre-camp on the relay UE regardless of whether the remote UE and the relay UE are within the coverage area of ​​the same base station. Therefore, in this example, remote UE 110 may select relay UE 112 for pre-camping. The scenarios and examples described above are provided for illustrative purposes only and are not intended to limit the exemplary embodiments in any way.

[0055] Returning to method 300, in 320, the remote UE 110 may attempt to access the network via the currently camped link. For example, if the remote UE 110 selects to camp on the relay link of the relay UE 112 in 315, the remote UE 110 may attempt to access the network via the relay link. If the remote UE 110 selects to camp on the Uu link of the gNB 120A in 315, the remote UE 110 may attempt to access the network via the Uu link. In order to access the network, the remote UE 110 may perform various operations, including but not limited to downlink synchronization, uplink synchronization, random access (RA) procedures, establishing a dedicated connection, etc. However, the exemplary embodiments are not limited to accessing the network in any particular manner and may be applied to remote UEs 110 that utilize any appropriate access mechanism.

[0056] In 325, the remote UE 110 determines whether the attempt to access the network via the currently camped link was successful. If the attempt was successful, the method 300 may end, and the remote UE 110 may perform the full range of functionality normally available to the UE 110 via the network connection. If the attempt was unsuccessful, the method 300 may continue to 330.

[0057] In 330, the remote UE 110 may initiate a link reselection procedure or switch to a different link and attempt to access the network again.

[0058] As described above, remote UE 110 and relay UE 112 may participate in an authentication procedure for determining whether remote UE 110 is allowed to camp on the relay link of relay UE 112. Figure 5a to Figure 5b An example of an authentication procedure is shown in .

[0059] Figure 5a to Figure 5bEach shows an exemplary signaling diagram related to an authentication procedure for camping on a relay link. Figure 5a A signaling diagram 500 between a remote UE 110 and a relay UE 112 is shown. In 505, the remote UE 110 searches for a link to camp on. During the search, the relay UE 112 may be detected by the remote UE 110. For example, in 510, the relay UE 112 may broadcast a solicitation signal. The solicitation signal may indicate to the remote UE 110 that the relay UE 112 is capable of providing a relay link, and may include a relay ID and a cell ID corresponding to the base station on which the relay UE 110 is camping.

[0060] In 515, the remote UE 110 determines whether the remote UE 110 is allowed to camp on the relay UE 112 by referring to a set of relayIDs stored at the remote UE 110. For example, the remote UE 110 may have received a set of relayIDs that the remote UE 110 is allowed to camp on in the link selection criteria. If the relayID included in the solicitation signal matches the releyID included in the link selection criteria, the remote UE 110 may camp on the relay UE 112.

[0061] At 520, remote UE 110 may transmit a discovery response to relay UE 112. The discovery response may indicate to relay UE 112 that remote UE 110 is allowed to camp on relay UE 112. At 525, relay UE 112 may record the identity of remote UE 110.

[0062] Figure 5b A signaling diagram 550 between a remote UE 110 and a relay UE 112 is shown. In 555, UE 110 transmits an access request to relay UE 112. In 560, if relay UE 112 determines that remote UE 110 is allowed to camp on the corresponding relay link, relay UE 112 may transmit an access accept message to remote UE 110. Alternatively, in 560, if relay UE 112 determines that remote UE 110 is not allowed to camp on the corresponding relay link, relay UE 112 may transmit an access reject message to remote UE 110. Therefore, in signaling diagram 550, relay UE 112 explicitly indicates to remote UE 110 whether remote UE 110 is allowed to camp on the corresponding relay link.

[0063] In 565, the relay UE 112 may record the identity of the remote UE 110. The signaling diagrams 500, 550 are intended only to provide examples of authentication procedures between the remote UE 110 and the relay UE 112 and are not intended to limit the exemplary embodiments in any way. Those skilled in the art will appreciate that any suitable authentication procedure may be implemented.

[0064] Figure 6 A method 600 for selecting a link based on link selection criteria is shown according to various exemplary embodiments. Figure 1 Network layout 100, Figure 2 UE 110 and Figure 3 Method 600 is described with reference to method 300 .

[0065] As described above, with reference to 315 of method 300, during the link selection procedure, the remote UE 110 may select a link to pre-empt using a link selection criterion configured by the network. Method 600 provides an example of how the remote UE 110 may select a link to pre-empt using, at least in part, a link selection criterion. However, the link selection criterion may be configured by the network in any of a variety of different ways. Thus, method 600 provides a general example of selecting a link using a link selection criterion, and is not intended to limit the exemplary embodiment to the link selection criterion described with reference to method 600. The exemplary embodiment may be applied to a link selection criterion configured by the network in any suitable manner.

[0066] In 605, the remote UE 110 searches for a base station to camp on. For example, the remote UE 110 may tune the transceiver 225 to various frequency bands. During the search, the remote UE 110 may collect measurement data corresponding to potential serving base stations. The remote UE 110 may also include information from the base station to be used to determine whether the corresponding link is suitable for camping.

[0067] In 610, the remote UE 110 determines whether the base station detected in 605 can be a suitable serving base station. For example, the measurement data corresponding to the base station can be compared with a threshold. If the measurement data meets the threshold, this can indicate to the remote UE 110 that the corresponding base station can be a suitable serving base station. Alternatively, the remote UE 110 may be out of coverage, and therefore, the base station may not be detected in 605. However, the above example is provided for illustrative purposes only, and the remote UE 110 may make this determination in any suitable manner.

[0068] If the remote UE 110 determines that there is no suitable serving base station, the remote UE 110 is out of coverage, and thus the remote UE 110 may search for a relay link to camp on. The search for a relay link will be described below with reference to 615-650.

[0069] In 615, the remote UE 110 determines whether a relayID has been provided to the remote UE 110 in the previously received link selection criteria. As described above, the remote UE 110 may receive a set of link relayIDs that the remote UE 110 is allowed to camp on in the link selection criteria. The link selection criteria may be stored in the memory arrangement 210 and may be used for scenarios where the remote UE 110 is out of coverage. As will be explained below, the relayID included in the link selection criteria may not be the only relay UE that the remote UE 110 is allowed to camp on.

[0070] If the remote UE 110 does not have access to a set of relay IDs from the link selection criteria, the method 600 continues to 635. If the remote UE 110 has access to a relay ID from the link selection criteria, the method 600 continues to 620. In 620, the remote UE 110 searches for a relay UE associated with the relay ID included in the link selection criteria. In 625, the remote UE 110 collects measurement data for any relay UE detected in 620 to determine the quality of the corresponding relay link.

[0071] In 630, the remote UE 110 determines whether the relay link associated with the relayID included in the link selection criteria can be a suitable serving relay link. For example, the measurement data can be compared with a quality criterion threshold. However, this example is for illustrative purposes only, and the remote UE 110 can make this determination in any suitable manner.

[0072] If the remote UE 110 determines that the relay link associated with the relayID included in the link selection criteria is a suitable serving relay link, the method 600 continues to 650 where the remote UE 110 camps on the relay link.

[0073] If the remote UE 110 determines that the relay link associated with the relayID included in the link selection criteria is not a suitable serving relay link, the method 600 continues to 635 .

[0074] In 635, the remote UE 110 searches for any relay UEs to camp on. In 640, the remote UE 110 determines that the relay link identified in 635 can serve as a suitable serving relay link.

[0075] In 645, the remote UE 110 may determine whether the remote UE 110 is allowed to camp on the relay link determined to be a suitable serving relay link. For example, the remote UE 110 and the relay UE corresponding to the relay link may participate in an authentication procedure (e.g., signaling diagrams 500, 550, or any other suitable procedure). If the remote UE 110 is not allowed to camp on the relay UE, the method 600 returns to 640. If the remote UE 110 is allowed to camp on the relay UE, the method 600 continues to 650. In 650, the remote UE 110 camps on the relay UE. Subsequently, the method 600 ends.

[0076] Returning to 610, if the base station is determined to be a suitable serving base station, the method 600 continues to 655. In 655, the remote UE 110 camps on the Uu link of the serving base station. When camping on the serving base station, the remote UE 110 may receive the link selection criteria, or the remote UE 110 may have previously received the link selection criteria. The link selection criteria may be implemented when the remote UE 110 camps on the base station.

[0077] At 660, the remote UE 110 determines whether the remote UE 110 is allowed to camp on the relay link. If the remote UE 110 is not allowed to camp on the relay link, the method 600 ends with the remote UE 110 camping on the Uu link of the serving base station. If the remote UE 110 is allowed to camp on the relay link, the method 600 continues to 665.

[0078] In 665 , the remote UE 110 searches for a relay UE corresponding to the relayID included in the link selection criteria. In 670 , the remote UE 110 collects measurement data corresponding to any relay UE detected in 665 .

[0079] In 675, the remote UE 110 determines whether the relay link corresponding to the relayID included in the link selection criteria can be a suitable relay service link. If the remote UE 110 determines that there is a suitable relay service link, the method 600 continues to 650, in which the remote UE 110 camps on the relay link. If the remote UE 110 determines that there is no suitable relay service link, the method 600 continues to 680.

[0080] In 680, the remote UE 110 searches for any relay UE to camp on. In 685, the remote UE 110 determines that the relay link identified in 680 can serve as a suitable serving relay link. In 690, the remote UE 110 determines whether the remote UE 110 is allowed to access the relay link. For example, the remote UE 110 and the relay UE corresponding to the relay link may participate in an authentication procedure (e.g., signaling diagrams 500, 550 or any other suitable procedure). If the remote UE 110 is not allowed to access the relay link, the method 600 ends with the remote UE 110 camping on the Uu link of the serving base station. If the remote UE 110 is allowed to access the relay link, the method 600 continues to 695.

[0081] The remote UE 110 determines whether the relay link is prioritized over the Uu link in 695. For example, in the link selection criteria, the network may indicate that the relay link is to be prioritized over the Uu link, or the Uu link is to be prioritized over the relay link.

[0082] If the relay link is prioritized, the method 600 continues to 650 where the remote UE 110 camps on the relay link. If the relay link is not prioritized, the method 600 ends with the remote UE 110 camping on the Uu link of the serving base station.

[0083] Figure 7 A signaling diagram 700 is shown relating to when a remote UE 110 may initiate link selection. Figure 1 Network layout 100, Figure 2 UE 110 and Figure 3 The method 300 is described in a signaling diagram 700 .

[0084] Signaling diagram 700 includes remote UE 110, relay UE 112, and gNB 120A. Initially, remote UE 110 is not camped on relay UE 112 or gNB 120A and is in RRC idle state. Therefore, the link selection procedure is initiated before camping on the link.

[0085] The remote UE 110 searches for base stations and relay links to camp on at 705. During the search, the remote UE 110 may collect measurement data to determine whether a base station or relay UE detected while searching can provide a suitable serving link.

[0086] In 710, gNB 120A may broadcast configuration information to remote UE 110. The configuration information may include link selection criteria. In this example, the link selection criteria may indicate to remote UE 110 that remote UE 110 is allowed to camp on relay UE 112 and that the relay link takes precedence over the Uu link. gNB 120A may perform the broadcast during the search in 705.

[0087] In 715, relay UE 112 may broadcast configuration information. The configuration information indicates to remote UE 110 that relay UE 112 is in the vicinity of remote UE 110. Relay UE 112 may perform the broadcast during the search in 705. Thus, during the search 705, remote UE 110 may have received configuration information from both relay UE 112 and gNB 120A.

[0088] In 720, remote UE 110 and relay UE 112 perform an authentication procedure. In 725, remote UE 110 camps on the relay link of relay UE 112. As described above, in this example, the relay link takes precedence over the Uu link, and therefore, remote UE 110 selects the relay link of relay UE 112 for camping.

[0089] When camping on the relay link, the remote UE 110 is configured to receive a signal from the gNB 120A via the relay link. Thus, in 730, the gNB 120A transmits a signal to the remote UE 110. The signal may be broadcast information, system information, paging, or any other suitable type of information that can be received by the remote UE 110 while the remote UE 110 is in the RRC idle state (or RRC inactive state).

[0090] Since remote UE 110 camps on the relay link of relay UE 112, the signal sent by gNB 120A to remote UE 110 in 730 is initially sent to relay UE 112. In 735, relay UE 112 relays the signal to remote UE 110 on behalf of gNB 120A.

[0091] The remote UE 110 initiates an RRC procedure to transition from the RRC idle state to the RRC connected state in 740. Thus, the RRC connection is established, and the remote UE 110 is able to access the network via the relay link.

[0092] Figure 8 A signaling diagram 800 is shown relating to when a remote UE 110 may initiate link selection. Figure 1 Network layout 100, Figure 2 UE 110 and Figure 3 The method 300 is described in a signaling diagram 800 .

[0093] Signaling diagram 800 includes remote UE 110, relay UE 112, and gNB 120A. Initially, in 805, remote UE 110 camps on the Uu link of gNB 120A. Therefore, the link selection procedure is initiated when remote UE 110 camps on the link.

[0094] At 810, gNB 120A may broadcast configuration information to remote UE 110. The configuration information may include link selection criteria. In this example, the link selection criteria may indicate to remote UE 110 that remote UE 110 is allowed to camp on relay UE 112 and that the relay link takes precedence over the Uu link. gNB 120A may perform the broadcast when remote UE 110 camps on the Uu link of gNB 120A.

[0095] In 815, relay UE 112 may broadcast configuration information. The configuration information indicates to remote UE 110 that relay UE 112 is in the vicinity of remote UE 110. Relay UE 112 may perform the broadcast during the search in 705. Thus, when remote UE 110 camps on the Uu link of gNB 120A, remote UE 110 may have received configuration information from both relay UE 112 and gNB 120A.

[0096] In 820, remote UE 110 and relay UE 112 perform an authentication procedure. In 825, remote UE 110 camps on the relay link of relay UE 112. As described above, in this example, the relay link takes precedence over the Uu link, and therefore, remote UE 110 selects the relay link of relay UE 112 for camping.

[0097] The remote UE 110 initiates an RRC procedure to transition from the RRC idle state to the RRC connected state in 830. Thus, the RRC connection is established, and the remote UE 110 is able to access the network via the relay link.

[0098] If the remote UE 110 cannot access the network via the selected link, the remote UE 110 may perform link selection and attempt to access the network via the selected link. Therefore, the remote UE 110 may attempt to access the network on a relay link or a Uu link. Alternatively, if the link is a suitable service link, the remote UE 110 may directly select another type of link and attempt to access the network via the selected link. Therefore, the remote UE 110 may attempt to access the network using a type of link that was not used in a previous unsuccessful attempt. For example, if the remote UE 110 cannot establish an RRC connection using a relay link in the signaling diagrams 700, 800, the remote UE 110 may attempt to establish an RRC connection using the Uu link of the gNB 120A.

[0099] If remote UE 110 is currently camped on a Uu link of a first base station (e.g., gNB 120A) and then moves to the coverage area of ​​a second base station (e.g., gNB 120B), a link selection procedure may be initiated. Thus, if the second base station allows remote UE 110 to access the network via a relay link, remote UE 110 may perform a search and attempt to access the network using a relay UE within the coverage area of ​​the second base station.

[0100] Those skilled in the art will appreciate that the exemplary embodiments described above may be implemented with any suitable software configuration or hardware configuration or combination thereof. Exemplary hardware platforms for implementing the exemplary embodiments may include, for example, Intel x86-based platforms with compatible operating systems, Windows OS, Mac platforms and MAC OS, mobile devices with operating systems such as iOS, Android, etc. In other examples, the exemplary embodiments of the above methods may be embodied as a program including lines of code stored on a non-transitory computer-readable storage medium, which, when compiled, may be executed on a processor or microprocessor.

[0101] It is understood that the use of personally identifiable information should be subject to privacy policies and practices that are generally recognized to meet or exceed industry or government requirements for maintaining 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 the authorized use should be clearly stated to users.

[0102] It will be apparent to those skilled in the art that various modifications may be made to the present disclosure without departing from the spirit or scope of the present disclosure. Therefore, the present disclosure is intended to cover modifications and variations of the present disclosure, provided that these modifications and variations are within the scope of the appended claims and their equivalents.

Claims

1. A method comprising: At a remote user equipment UE, the remote UE is configured to access a network via one of a direct link with a base station or a relay link with a relay UE: receiving a link selection criterion, the link selection criterion being configured by the network, wherein the link selection criterion comprises at least one relayID, the at least one relayID indicating at least one relay UE that the remote UE is allowed to camp on; Identifying a relay UE available for pre-camping, the identification being based on the relay UE being associated with one of the at least one relayID; Selecting the relay UE based on the link selection criterion; Pre-occupying the relay link corresponding to the relay UE; as well as A network access procedure via the relay link is initiated.

2. The method according to claim 1, further comprising: identifying the base station available for pre-camping; determining that the network access procedure via the relay link has failed; selecting the base station in response to determining that the network access procedure via the relay link has failed; camping on the direct link corresponding to the base station; as well as The network access procedure via the direct link is initiated. The method of claim 1 , wherein the link selection criteria indicates that the relay link is to be prioritized.

4. The method of claim 1, wherein identifying that the relay UE is available for camping comprises: The relayID associated with the relay UE is received in a signal broadcast by the relay UE, and wherein selecting the relay UE based on the link selection criteria includes identifying that the relayID included in the link selection criteria is the same as the relayID received in the broadcast from the relay UE.

5. The method of claim 1, wherein the link selection criteria comprises rules related to one or more of link quality, link-based priority, service-based priority, and device type priority.

6. The method according to claim 1, further comprising: Executing a link authentication procedure to the relay UE, the link authentication procedure comprising: transmitting an access request to the relay UE; and An access request accept message is received from the relay UE.

7. The method according to claim 1, further comprising: Executing a link authentication procedure to the relay UE, the link authentication procedure comprising: receiving a signal from the relay UE, the signal including a relayID associated with the relay UE; It is determined that the relayID included in the signal received from the relay UE matches the relayID stored on the remote UE.

8. The method according to claim 7, wherein the authentication procedure further comprises: A discovery response is transmitted to the relay UE.

9. The method of claim 1, wherein selecting the relay link occurs when the remote UE camps on the direct link of the base station.

10. The method of claim 1, wherein selecting the relay link occurs when the remote UE is not camped on any link.

11. A remote user equipment UE, comprising: a transceiver configured to access a network via one of a direct link with a base station or a relay link with a relay UE; and A processor configured to perform operations comprising: receiving a link selection criterion, the link selection criterion being configured by the network, wherein the link selection criterion comprises at least one relayID, the at least one relayID indicating at least one relay UE that the remote UE is allowed to camp on; Identifying a relay UE available for pre-camping, the identification being based on the relay UE being associated with one of the at least one relayID; Selecting the relay UE based on the link selection criterion; camping on the relay link corresponding to the relay UE; and A network access procedure via the relay link is initiated.

12. The remote UE of claim 11, the operations further comprising: identifying the base station available for pre-camping; determining that the network access procedure via the relay link has failed; selecting the base station in response to determining that the network access procedure via the relay link has failed; camping on the direct link corresponding to the base station; as well as The network access procedure via the direct link is initiated.

13. The remote UE of claim 11, wherein the link selection criteria indicates that the relay link is to be prioritized.

14. The remote UE of claim 11, wherein the link selection criteria comprises rules related to one or more of link quality, link-based priority, service-based priority, and device type priority.

15. An integrated circuit comprising: a circuit system configured to receive a link selection criterion, the link selection criterion configured by a network, wherein the link selection criterion includes at least one relayID, the at least one relayID indicating at least one relay UE that the remote UE is allowed to camp on; circuitry configured to identify a relay UE available for camping, the identification based on the relay UE being associated with one of the at least one relayID; circuitry configured to select the relay UE based on the link selection criteria; circuitry configured to cause a user equipment UE to camp on a relay link corresponding to the relay UE; and Circuitry configured to initiate a network access procedure via the relay link.

16. The integrated circuit of claim 15, wherein the link selection criteria comprises rules related to one or more of link quality, link-based priority, service-based priority, and device type priority.

17. The integrated circuit of claim 15, wherein identifying that the relay UE is available for camping comprises: The relayID associated with the relay UE is received from the relay UE, and wherein selecting the relay UE based on the link selection criteria includes identifying that the relayID included in the link selection criteria is the same as the relayID received from the relay UE.

18. The integrated circuit of claim 15, wherein selecting the relay link occurs i) when the remote UE is camped on a Uu link of a base station or ii) when the remote UE is not camped on any link.

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