System and method for low power wake-up signaling in sidelink relay devices
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2026-02-02
- Publication Date
- 2026-08-13
Smart Images
Figure IB2026050955_13082026_PF_FP_ABST
Abstract
Description
[0001] SYSTEM AND METHOD FOR LOW POWER WAKE-UP SIGNALING IN SIDELINK RELAY DEVICES
[0002] Field of the Invention
[0003] The present invention relates to wireless communication systems, and more particularly to a system and method for supporting low power wake-up signaling in sidelink relay devices.
[0004] Background of the Invention
[0005] Wireless communication systems have become an integral part of modern society, enabling connectivity across vast distances and supporting a wide range of applications. As these systems continue to evolve, there is an increasing focus on improving energy efficiency and extending network coverage, particularly for devices operating in challenging environments or with limited power resources.
[0006] One area of development in wireless communications is the use of sidelink relay devices. These devices can act as intermediaries between a network base station and remote user equipment (UE), extending network coverage and improving connectivity in areas where direct communication with the base station may be difficult or impossible. Sidelink relay devices can be particularly useful for supporting Internet of Things (loT) devices, sensors, and other low-power devices that may be deployed in remote or hard-to-reach locations.
[0007] Another technology that has gained attention in recent years is the use of wake-up signaling. This approach allows devices to remain in a low-power sleep state for extended periods, conserving energy, while still maintaining the ability to quickly respond to network communications when needed. Wake-up signaling typically involves a low-power receiver that can detect specific signals and activate the device's main communication systems when necessary.
[0008] The combination of sidelink relay technology and wake-up signaling presents opportunities for further improving the energy efficiency andcoverage of wireless networks. However, implementing these technologies together also introduces new challenges. For example, managing wake-up signaling across multiple network hops, coordinating power-saving modes between relay devices and remote UEs, and ensuring reliable communication despite varying channel conditions all require careful consideration.
[0009] Furthermore, as wireless networks continue to support an increasing number of devices with diverse capabilities and requirements, there is a need for flexible and scalable solutions that can adapt to different network configurations and use cases. This includes supporting devices with varying levels of wake-up signal reception capabilities, as well as accommodating different types of traffic patterns and quality of service requirements.
[0010] As the demand for more efficient and reliable wireless communication continues to grow, researchers and engineers are exploring new approaches to address these challenges and improve the overall performance of wireless networks.
[0011] Objective of the Invention
[0012] The principal objective of the present invention is to provide a method and system for enabling LP-WUS operation in sidelink relay devices, allowing efficient wake-up signalling for both relay UEs and associated remote UEs while optimizing power consumption.
[0013] Another objective of the present invention is to enhance powersaving mechanisms in relay UEs by implementing an intelligent LP-WUS monitoring strategy that dynamically adapts based on network configurations and remote UE capabilities.
[0014] Another objective of the present invention is to introduce a systematic approach for managing wake-up signalling in sidelink relay devices, ensuring uninterrupted paging support even when some remote UEs do not support LP-WUS.Another objective of the present invention is to minimize the energy consumption of relay UEs by efficiently coordinating between LP-WUS and main radio (MR) monitoring, thereby achieving optimal power efficiency in NR networks.
[0015] Another objective of the present invention is to provide a scalable and adaptive method for relay UEs to request and utilize temporary LP-WUS identifiers for non-LP-WUS-capable remote UEs, ensuring seamless paging and wake-up operations.
[0016] A further objective of the present invention is to improve network reliability and coverage extension by enabling relay UEs to maintain efficient wake-up signalling while preserving overall power efficiency and communication performance.
[0017] Summary of the Invention
[0018] This summary is provided to introduce a selection of concepts in a simplified form that are further described below in the detailed description. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter.
[0019] According to an aspect of the present invention, a method is provided. The method includes establishing, by a relay user equipment (UE), an association with a remote UE. The relay UE indicates support for low power wake-up signal (LP-WUS) to the remote UE. The relay UE receives an indication from the remote UE of support for LP-WUS and a paging identifier and also ID which is used for wake-up indication of the remote UE. The relay UE monitors LP-WUS monitoring occasions (LO) associated with paging occasions (PO) of the relay UE and also the LOs associated with the POs of the remote UEs.
[0020] According to other aspects of the present invention, the method may include one or more of the following features. The relay UE may receive a wake-up indication corresponding to an identifier associated with the remoteUE and send a wake-up indication to remote UE over PC5 link. The relay UE may receive a paging message in the monitored paging occasion. The relay UE may determine that the paging message contains a paging identifier associated with the remote UE. The relay UE may indicate the paging message to the remote UE via a PC5 link.
[0021] According to another aspect of the present invention, relay user equipment (UE) is provided. The relay UE includes a processor and a memory. The memory contains instructions executable by the processor whereby the relay UE is operative to: establish an association with a remote UE; indicate support for low power wake-up signal (LP-WUS) to the remote UE; receive an indication from the remote UE of non-support for LP-WUS, UE DRX and a paging identifier of the remote UE; request, from a network node, LP-WUS identifiers to be used for monitoring wake-up indications for the remote UE; receive, from the network node, configuration of LP-WUS identifiers for the remote UE; and monitor LP-WUS monitoring occasions associated with paging occasions of the relay UE and the LOs associated with the configured IDs of the remote UEs.
[0022] According to other aspects of the present invention, the relay UE may be further operative to: receive a wake-up indication corresponding to an identifier associated with the remote UE; indicate to a main radio of the relay UE to monitor a corresponding paging occasion; receive a paging message in the monitored paging occasion; determine that the paging message contains a paging identifier associated with the remote UE; and indicate the paging message to the remote UE via a PC5 link.
[0023] According to another aspect of the present invention, a non-transitory computer-readable storage medium is provided. The non-transitory computer-readable storage medium stores program instructions that, when executed by a processor of a relay user equipment (UE), cause the relay UE to: establish an association with a remote UE; indicate support for low power wake-up signal (LP-WUS) to the remote UE; receive an indicationfrom the remote UE of non-support for LP-WUS, UE DRX and a paging identifier of the remote UE; request, from a network node, LP-WUS identifiers to be used for monitoring wake-up indications for the remote UE; receive, from the network node, configuration of LP-WUS identifiers for the remote UE; and monitor LP-WUS monitoring occasions associated with paging occasions of the relay UE and the LOs associated with the configured IDs of the remote UEs.
[0024] According to other aspects of the present invention, the program instructions may further cause the relay UE to: receive a wake-up indication corresponding to an identifier associated with the remote UE; indicate to a main radio of the relay UE to monitor a corresponding paging occasion; receive a paging message in the monitored paging occasion; determine that the paging message contains a paging identifier associated with the remote UE; and indicate the paging message to the remote UE via a PC5 link.
[0025] The foregoing general description of the illustrative embodiments and the following detailed description thereof are merely exemplary aspects of the teachings of this disclosure and are not restrictive.
[0026] Brief description of the drawings
[0027] The figures described below depict various aspects of the system and methods disclosed herein. It should be understood that each figure depicts an embodiment of a particular aspect of the disclosed system and methods, and that each of the figures is intended to accord with a possible embodiment thereof. Further, wherever possible, the following description refers to the reference numerals included in the following figures, in which features depicted in multiple figures are designated with consistent reference numerals.
[0028] FIG. 1 illustrates a conventional wireless network architecture in which a user equipment (UE) operates as a UE to Network (U2N) sidelink relay device (100), in accordance with aspects of the present invention.FIG. 2 depicts a system diagram of a wireless communication system with low power wake-up radio support (200), in accordance with example embodiments.
[0029] FIG. 3 illustrates a scenario where both the remote UEs and the relay UE support the LP-WUS feature (300), in accordance with the present invention.
[0030] FIG. 4 illustrates a scenario where the remote UEs do not support the LP-WUS feature, while the relay UE does (400), according to one embodiment of the present invention.
[0031] FIG. 5 illustrates a state machine diagram depicting operational states and transitions of a relay user equipment implementing LP-WUS functionality (500), according to another embodiment of the present invention.
[0032] FIG. 6 illustrates a block diagram of a network node implementing LP-WUS identifier allocation and management functionality (600), according to another embodiment of the present invention.
[0033] Persons skilled in the art will appreciate that elements in the figures are illustrated for simplicity and clarity and may have not been drawn to scale. For example, the dimensions of some of the elements in the figure may be exaggerated relative to other elements to help to improve understanding of various exemplary embodiments of the present disclosure.
[0034] Throughout the drawings, it should be noted that like reference numbers are used to depict the same or similar elements, features, and structures.
[0035] Detailed Description of the Invention
[0036] The following description with reference to the accompanying drawings is provided to assist in a comprehensive understanding of exemplary embodiments of the invention as defined by the claims and their equivalents. It includes various specific details to assist in that understanding but these are to be regarded as merely exemplary.Accordingly, those of ordinary skill in the art will recognize that various changes and modifications of the embodiments described herein can be made without departing from the scope and spirit of the invention. In addition, descriptions of well-known functions and constructions are omitted for clarity and conciseness.
[0037] The terms and words used in the following description and claims are not limited to the bibliographical meanings but are merely used by the inventor to enable a clear and consistent understanding of the invention. Accordingly, it should be apparent to those skilled in the art that the following description of exemplary embodiments of the present invention are provided for illustration purpose only and not for the purpose of limiting the invention as defined by the appended claims and their equivalents.
[0038] It is to be understood that the singular forms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to “a component surface” includes reference to one or more of such surfaces.
[0039] By the term “substantially” it is meant that the recited characteristic, parameter, or value need not be achieved exactly, but that deviations or variations, including for example, tolerances, measurement error, measurement accuracy limitations and other factors known to those of skill in the art, may occur in amounts that do not preclude the effect the characteristic is intended to provide.
[0040] Figures discussed below, and the various embodiments used to describe the principles of the present disclosure in this patent document are by way of illustration only and should not be construed in any way that would limit the scope of the disclosure. Those skilled in the art will understand that the principles of the present disclosure may be implemented in any suitably arranged system. The terms used to describe various embodiments are exemplary. It should be understood that these are provided to merely aid the understanding of the description, and that their use and definitions, inno way limit the scope of the invention. Terms first, second, and the like are used to differentiate between objects having the same terminology and are in no way intended to represent a chronological order, unless where explicitly stated otherwise. A set is defined as a non-empty set including at least one element.
[0041] Figure 1 illustrates a conventional wireless network architecture for supporting low power wake-up signal functionality. The wireless network architecture may include a network node (105), a relay node (110) that operates as a user equipment (UE) capable of establishing a radio link with the network node and relaying communications to one or more remote nodes, and one or more remote nodes (115) that are associated with the relay node for network connectivity.
[0042] In some cases, the network node (105), which may be a base station, gNB (gNodeB), or any other access point entity configured to transmit paging messages and control signalling, may communicate with the relay node (110) through a llu link. The llu link may represent a wireless interface between the network node and user equipment, defined in 3GPP specifications as the radio access link between a UE and the network.
[0043] The relay node (110), also referred to herein as a "relay user equipment" or "relay UE," operates as a Layer 2 UE-to-Network (U2N) relay device, a designation indicating that it functions as a user equipment from the network node's perspective while simultaneously providing relay services to one or more remote UEs. The term "user equipment" or "UE" as used throughout this specification refers to any wireless communication device capable of establishing a radio link with a network node and includes both standalone UEs and relay UEs. The term "remote UE" denotes a UE that is associated with the relay UE for the purpose of obtaining connectivity to the network node and may or may not support Low Power Wake-Up Signal (LP-WUS) functionality.In some cases, the network architecture may allow the relay node (110) to serve as an intermediary, forwarding communications between the network node 105 and remote node (115). This configuration may be useful when the remote nodes (115) are outside the direct coverage area of the network node (105).
[0044] The relay node (110) may be positioned to facilitate communication with both the network node 105 and multiple remote nodes (115) through their respective wireless interfaces. In some implementations, the relay node (110) may support a low power wake up radio (LP-WUR) functionality. This functionality may allow the relay node (110) to operate in a powerefficient manner while maintaining connectivity with both the network node 105 and the remote node (115).
[0045] Figure 2 depicts a system diagram of a wireless communication system with low power wake-up radio support (200). The system may include a relay device (200) that communicates with a network node (205) and a remote device (225).
[0046] The relay device (200) may comprise three main components: a wake-up receiver (210), a main radio module (215), and a sidelink radio module (220). The "wake-up receiver" (210) is a dedicated, energy-efficient receiver component capable of detecting low-power wake-up signals over an extended period with minimal power consumption. The "main radio module" (215) is the primary RF transceiver of the relay device, capable of performing full-bandwidth, full-power communication including synchronization, paging message reception, data transmission, and protocol processing. The "sidelink radio module" (220) is configured specifically for device-to-device communication over the PC5 interface.
[0047] In some cases, network node (205) may communicate with the relay device (200) through two links - a llu link connected to the wake-up receiver (210) and a main radio link connected to the main radio module (215). Thewake-up receiver (210) may operate as a low-power receiver for detecting wake-up signals from the network node (205).
[0048] The main radio module (215) may handle the primary communication functions with network node (205). In some implementations, the sidelink radio module (220) may manage communications with the remote device (225) through PC5 links. The system may show connections to multiple instances of remote device (225), illustrating the relay device's ability to communicate with multiple remote devices simultaneously.
[0049] In some cases, the relay device (200) may serve as an intermediary node, receiving signals from the network node (205) through either the wake-up receiver (210) or main radio module (215), and forwarding relevant information to the remote device (225) through the sidelink radio module (220) via PC5 links.
[0050] The term "low power wake-up signal" or "LP-WUS" denotes a brief, low-power signal transmitted by the network node that is intended to alert a relay UE (or a UE receiving on behalf of a remote UE) that a paging message is imminent. The LP-WUS signal is designed to be detectable by the dedicated low-power wake-up receiver (210) while consuming substantially less power than maintaining continuous main radio monitoring. Upon reception of an LP-WUS indication, the relay device activates its main radio module (215) in time to receive the corresponding paging message during the designated paging occasion.
[0051] The relay device may monitor wake up indications for remote devices. In some implementations, the wake-up receiver may monitor wake up signals from the network node that are intended for both the relay device itself and for associated remote devices. This monitoring may allow the relay device to conserve power by keeping the main radio module in a low-power state until a wake-up signal is received.
[0052] When a wake-up signal intended for a remote device is detected by the wake-up receiver, the relay device may activate its main radio moduleto receive further information from the network node. The relay device may then use its sidelink radio module to forward relevant information or paging messages to the appropriate remote device over the PC5 link.
[0053] This architecture may enable power-efficient operation of the relay device while maintaining connectivity and forwarding capabilities for remote devices that may not have direct network access or may not support low power wake-up functionality themselves.
[0054] In one embodiment, the relay device (200) is associated with a plurality of remote devices (225) having heterogeneous LP-WUS capabilities. In such cases, the wake-up receiver (210) may be configured to monitor wake-up signals both for the relay device (200) itself and for remote devices (225) that lack LP-WUS support. This arrangement enables the relay device (200) to apply differentiated power-saving strategies for different remote devices based on their capabilities and service requirements, thereby improving overall energy efficiency and flexibility of the wireless communication system.
[0055] Figure 3 illustrates a sequence diagram (300) showing the communication flow between a remote user equipment (305), a relay user equipment (310), and a network node (315) for supporting low-power wakeup signal (LP-WUS) functionality.
[0056] The sequence begins with an association step (320) where the remote user equipment (305) may be associated with the relay user equipment (310). Following this association, the relay user equipment (310) may indicate its support for LP-WUS to the remote user equipment (305). In response, the remote user equipment (305) may indicate its support of LP-WUS, along with its Paging ID, UE DRX parameters and also ID which is used for wake-up indication.
[0057] In another embodiment, when the network node (315) does not immediately configure LP-WUS identifiers for the remote user equipment (305), the relay user equipment (310) may independently determineprovisional LP-WUS identifiers for the remote user equipment (305) using a deterministic mapping algorithm based on the remote user equipment’s Paging ID and DRX parameters. The independently determined identifiers may be used by the wake-up receiver of the relay user equipment (310) to monitor LP-WUS occasions corresponding to predicted paging occasions of the remote user equipment (305) until explicit configuration is received from the network node (315). Once the network node (315) provides LP-WUS identifiers through higher-layer signalling, the relay user equipment (310) may replace the provisional identifiers with network-assigned identifiers to maintain consistent operation with network policies.
[0058] A monitoring block (325) may then occur where the wake-up receiver of the relay user equipment (310) may monitor LP-WUS for both it and the remote user equipment (305) during listening occasions associated with both devices. This monitoring may occur provided the conditions for using the wake-up receiver are satisfied. Specifically, the relay UE calculates a "paging occasion" or "PO" for each device including the relay UE itself and each associated remote UE based on that device's unique identity and its discontinuous reception (DRX) cycle parameters. A paging occasion is the designated time window during which the network node transmits paging messages for that device.
[0059] When an LP-WUS indication carrying the wake-up ID of the remote user equipment (305) is received from the network node (315), an indication block (330) may begin. During this phase, the relay user equipment (310) may send a wake-up indication to the remote UE over the PC5 interface; the wake-up receiver of the relay user equipment (310) may instruct the main radio module to wake up and monitor the paging occasion for the remote user equipment (305).
[0060] Upon receiving a paging message containing the ID of the remote user equipment (305) from the network node (315), the relay userequipment (310) may forward this paging indication to the remote user equipment (305) over the PC5 interface, as shown in step 300.
[0061] In some cases, if the relay user equipment (310) is not configured with wake-up IDs for the remote user equipment (305), the relay user equipment (310) may stop using the wake up receiver for wake up indication and may move the main radio module to an active state to monitor paging occasions of the remote user equipment (305).
[0062] This communication flow may enable power-efficient operation of the relay user equipment while maintaining connectivity and forwarding capabilities for the remote user equipment 305 that may not have direct network access or may not support low power wake-up functionality.
[0063] Figure 4 illustrates a scenario where the remote UEs do not support the LP-WUS feature, while the relay UE does (400), showing the communication flow between a remote user equipment (405), a relay user equipment (410), and a gNB (415) for supporting Low Power Wake-Up Signal (LP-WUS) functionality.
[0064] The sequence begins with a step (420) where the remote user equipment (405) may be associated with the relay user equipment (410). Following this association, the relay user equipment (410) may indicate its support for LP-WUS to the remote user equipment (405). In response, the remote user equipment (405) may indicate its non-support of LP-WUS along with its Paging ID and UE DRX parameters to the relay user equipment (410).
[0065] In a further embodiment, when LP-WUS operation is temporarily unavailable, for example due to interference on the LP-WUS channel or depletion of LP-WUS identifiers at the network node (415), the relay user equipment (410) may transition to a fallback mode in which the main radio module performs MR-only monitoring of paging occasions for one or more affected remote user equipments (405). In this mode, the relay user equipment (410) may selectively apply MR-only monitoring only to thoseremote user equipments (405) that require higher reliability or low-latency service, while continuing to use LP-WUS -based monitoring for other remote user equipments. When LP-WUS support is restored, the relay user equipment (410) may revert from MR-only monitoring to LP-WUS-based monitoring according to configuration received from the gNB (415), thereby providing graceful degradation and restoration of power-efficient operation.
[0066] In some cases, the relay user equipment (410) may forward this information to the gNB (415) through a "SIAssistancelnformation" message (also referred to as a "SIUEAssistanceMessage"). The "SIAssistancelnformation" message is a Layer 3 signalling message whereby a relay UE indicates to the network node its support for LP-WUS functionality and provides a list of associated remote UEs that lack LP-WUS support, along with their paging identifiers and DRX parameters. This message may include a flag indicating the relay user equipment 410's support for LP-WUS and a list of remote user equipment (405) without LP-WUS support. By sending this message, the relay user equipment (410) may request LP-WUS IDs or group IDs from the gNB (415) for the remote user equipment (405) that do not support LP-WUS.
[0067] The gNB (415) may respond with an "RRCReconfiguration" message. This message may contain a list of LP-WUS identifiers for the relay user equipment (410) to use when monitoring wake-up indications. An "LP-WUS identifier" or "wake-up identifier" is any identifier, code, or group identifier used by the relay UE and network to correlate a received LP-WUS indication with a particular remote UE. The identifier may be assigned by the network (as in this scenario) or independently determined by the relay UE according to a predefined algorithm. In this way, the gNB (415) may configure the relay user equipment (410) with identifiers for monitoring LP-WUS based wake-up indications for the remote user equipment (405).
[0068] A monitoring box (425) in the sequence diagram (400) shows that if conditions to use the wake-up receiver are satisfied, the wake-up receivermay monitor LP-WUS for both the relay user equipment (410) and the remote user equipment (405) during listening occasions associated with both devices.
[0069] When an LP-WUS indication carrying a wake-up ID of the remote user equipment (405) is received, an indication box (430) shows that the wake-up receiver of the relay user equipment (410) may indicate to the main radio module to wake up and listen to the Paging Occasion (PO) of the remote user equipment (405).
[0070] The gNB (415) may then send a paging message carrying the UE ID of the remote user equipment (405). Upon receiving this paging message, the relay user equipment (410) may forward a paging indication over the PC5 interface to the remote user equipment (405).
[0071] This communication sequence may enable power-efficient operation of the relay user equipment (410) while maintaining connectivity and forwarding capabilities for the remote user equipment (405) that may not have direct network access or may not support low power wake-up functionality.
[0072] In some cases, the relay UE indicates the support for LP-WUS reception and the list of associated remote UEs to the gNB as part of RRC signalling such as SIAssistancelnformation message. The network associates the LP-WUS ID of the relay UE to the associated remote UEs and signals wake up indication for paging for both relay UE and all remote UEs. This method reduces the monitoring occasion for LR. The network stops using LP-WUS ID of relay UE for a remote UE if the association between that relay UE and remote UE changes. The relay UE updates the network about any change in association of remote UE. The network stops using LP-WUS ID of relay for the remote UEs whose association with that relay UE has changed.
[0073] Figure 5 illustrates a state machine diagram (500) depicting the operational states and transitions of a relay user equipment (UE)implementing low power wake-up signal (LP-WUS) functionality wherein. The relay UE cycles through four states: SLEEP state (505), LP-WUS MONITORING state (510), MR ACTIVE IDLE state (515), and MR PAGING state (520).
[0074] The term "state machine" as used herein refers to a computational model in which the relay UE operates in one of several discrete operational states and transitions between states based on external events (such as network broadcasts or signal receptions) and timing conditions.
[0075] The SLEEP state (505) represents the lowest power mode with approximately one microwatt (1pW) consumption, where all radio components are deactivated. The relay UE enters SLEEP upon completion of a paging occasion with no relevant messages received, wherein sleep state refers to a condition in which all radio components are deactivated, and power consumption is minimal.
[0076] The LP-WUS MONITORING state (510) activates the low-power wake-up receiver to monitor for wake-up signal indications, consuming approximately five milliwatts (5mW). The relay UE enters this state upon network broadcast of LP-WUS support capability, wherein LP-WUS MONITORING state refers to a condition in which the wake-up receiver is active and monitoring for wake-up signal indications while the main radio module remains inactive.
[0077] Upon receipt of a wake-up signal indication, the relay UE transitions to the MR ACTIVE IDLE state (515), activating the main radio module and consuming approximately one hundred milliwatts (100mW) as it synchronizes to the network timing, wherein MR ACTIVE IDLE state is a transition condition in which the main radio module has been activated and is synchronizing to network timing in preparation for paging message reception.
[0078] The MR PAGING state (520) represents active reception of paging messages, consuming approximately five hundred milliwatts (500mW)during the designated paging occasion. Upon message reception, if the paging message is addressed to an associated remote UE, the relay UE forwards the indication via PC5 interface, wherein MR PAGING state refers to the condition in which the main radio module is actively receiving and processing paging messages, as described FIG. 3 and FIG. 4.
[0079] Upon termination of the paging occasion, the relay UE returns to SLEEP state, completing the state machine cycle. This continuous cycling through low-power and brief active states achieves approximately 90% power reduction compared to conventional continuous main radio monitoring, thereby enabling efficient relay UE operation while maintaining paging support for associated remote UEs, as described in the system architecture illustrated in FIG. 2.
[0080] Figure 6 illustrates a block diagram of a network node (600) implementing low power wake-up signal (LP-WUS) identifier allocation and management functionality. The network node (605) comprises functional components responsible for coordinating LP-WUS identifiers for relay user equipment’s (UEs) serving remote UEs that do not support LP-WUS.
[0081] The network node (605) includes a network interface (610) configured to communicate with relay UEs and other network elements via standard wireless interfaces. The network interface (610) receives SIAssistancelnformation messages from relay UEs indicating their LP-WUS support capability and lists of associated remote UEs lacking LP-WUS support.
[0082] In one example embodiment, the processor (615) may implement an LP-WUS identifier reuse policy in which identifiers previously assigned to remote UEs that have been detached, handed over to another relay UE, or whose association timers have expired are returned to an available pool maintained in the storage (625). When a new SIAssistancelnformation message indicates that a relay UE has associated with additional remote UEs lacking LP-WUS support, the processor (615) selects identifiers fromthis pool according to predefined allocation rules, such as minimizing collisions within a geographical region or within a particular DRX group. The updated identifier assignments are then communicated to the relay UE through an RRCReconfiguration message, allowing efficient utilization of a limited LP-WUS identifier space while supporting dynamic changes in relay UE-remote UE associations.
[0083] The processor (615) executes LP-WUS identifier allocation algorithms upon receipt of assistance information from relay UEs. The processor (615) determines available LP-WUS identifiers from a managed pool, maps each identifier to specific remote UEs within each relay UE's association list, and calculates timing relationships based on each remote UE's discontinuous reception (DRX) cycle parameters. The processor (615) generates "RRCReconfiguration" messages; Layer 3 signalling messages defined in 3GPP specifications, containing the allocated LP-WUS identifiers, monitoring occasion offsets, and associated configuration parameters, and transmits these messages to the relay UEs via the network interface (610).
[0084] The memory (620) stores real-time operational data including active LP-WUS identifier allocations, relay UE-to-remote UE associations, and DRX configuration parameters for each remote UE. The memory (620) enables the processor (615) to track and update allocations dynamically as relay UE associations change.
[0085] The storage (625) maintains persistent data such as LP-WUS identifier pools, allocation policies, and historical records. The storage (625) provides long-term retention of configuration data used for policy optimization and troubleshooting.
[0086] The network node architecture depicted in FIG. 6 supports the network-coordinated LP-WUS identifier allocation pathway described in connection with FIG. 4 (scenario where the relay UE requests and receives LP-WUS identifiers from the network for remote UEs lacking LP-WUS support). This architecture enables efficient management of LP-WUSresources across multiple relay UEs and their associated remote UEs, as described in the method claims and detailed description sections.
[0087] A number of implementations have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the disclosure. Accordingly, other implementations are within the scope of the following claims.
Claims
We Claim:
1. A method for enabling Low Power Wake-Up Signal (LP-WUS) operation in a sidelink relay device, the method comprising:establishing an association between a relay user equipment (UE) and one or more remote UEs in a wireless communication network;receiving an indication from the remote UEs regarding their support or non-support for LP-WUS functionality;requesting, from a network node, a set of LP-WUS identifiers for remote UEs that do not support LP-WUS;receiving, from a network node, a configuration of LP-WUS identifiers corresponding to the remote UEs;monitoring LP-WUS occasions associated with the relay UE and the configured LP-WUS identifiers of the remote UEs;switching from LP-WUS to main radio (MR) monitoring for remote UEs lacking LP-WUS support when necessary; andforwarding paging messages received via MR monitoring to the respective remote UEs through a PC5 sidelink communication interface.
2. The method as claimed in claim 1 , further comprising:the relay UE independently determining LP-WUS identifiers for remote UEs that do not support LP-WUS, using predefined rules or algorithms, without relying on network configuration, and monitoring the corresponding LP-WUS occasions accordingly.
3. The method as claimed in claim 1 , further comprising:receiving a wake-up indication corresponding to an identifier associated with a remote UE; andactivating the main radio module of the relay UE to monitor the corresponding paging occasion.
4. The method as claimed in claim 3, further comprising:receiving a paging message in the monitored paging occasion; and determining whether the paging message contains a paging identifier corresponding to one of the remote UEs.
5. The method as claimed in claim 4, further comprising:transmitting the received paging message to the corresponding remote UE via a PC5 sidelink communication link.
6. The method as claimed in claim 1 , wherein the relay UE comprises:a wake-up receiver module for monitoring LP-WUS occasions; a main radio module for full-power operation when required; and a sidelink communication module for transmitting paging messages to remote UEs.
7. The method as claimed in claim 6, wherein the wake-up receiver module is configured to monitor LP-WUS occasions while the main radio module remains in a low-power state.
8. The method as claimed in claim 7, wherein upon detecting a wakeup signal intended for the remote UE, the wake-up receiver module activates the main radio module to receive further signalling from the network.
9. A relay user equipment (UE), comprising:a processor; anda memory storing instructions executable by the processor, wherein the relay UE is configured to:establish an association with one or more remote UEs in a wireless communication network;receive an indication from the remote UEs regarding their support or non-support for LP-WUS;request, from a network node, a set of LP-WUS identifiers for remote UEs that do not support LP-WUS;receive, from the network node, a configuration of LP-WUS identifiers corresponding to the remote UEs;monitor LP-WUS occasions associated with the relay UE and the configured LP-WUS identifiers of the remote UEs;switch from LP-WUS to main radio (MR) monitoring for remote UEs lacking LP-WUS support when necessary; andforward paging messages received via MR monitoring to the respective remote UEs through a PC5 sidelink communication interface.
10. The relay UE as claimed in claim 9, wherein the relay UE is further configured to:receive a wake-up indication corresponding to an identifier associated with a remote UE; andactivate its main radio module to monitor the corresponding paging occasion.
11. The relay UE as claimed in of claim 10, wherein the relay UE is further configured to:receive a paging message during the monitored paging occasion; anddetermine whether the paging message contains a paging identifier corresponding to a remote UE.
12. The relay UE as claimed in claim 11, wherein the relay UE is further configured to transmit the received paging message to the corresponding remote UE via a PC5 sidelink communication link.
13. The relay UE as claimed in claim 9, further comprising:a wake-up receiver module for monitoring LP-WUS occasions; a main radio module for full-power operation when required; anda sidelink communication module for transmitting paging messages to remote UEs.
14. The relay UE as claimed in claim 13, wherein the wake-up receiver module is configured to monitor LP-WUS occasions while the main radio module remains in a low-power state.
15. The relay UE as claimed in claim 14, wherein:Upon detecting a wake-up signal intended for a remote UE, the wake-up receiver module is configured to activate the main radio module to receive further signalling from the network.