Methods and apparatuses for relay communication in wireless communication system

Abstract

Embodiments of present disclosure provide a method (800) performed by the network node (202) for communicating with a first User Equipment, UE (204-1) via a relay path (208) The method comprises configuring a second UE (204-2) as a relay UE for the first UE, said second UE being arranged between the first UE and the network node via a first link (306) and a second link (308), respectively. The method comprises transmitting aggregation configuration information for each of the first UE and the second UE. At least a part of the aggregation configuration information is intended for use at each of the first UE and the second UE in configuring aggregation of transmissions between the first UE and the second UE in a protocol layer below a PDCP layer of the first UE. Corresponding network node, first and second UEs, and computer program products are also disclosed.

Description

[0001] METHODS AND APPARATUSES FOR RELAY COMMUNICATION IN WIRELESS COMMUNICATION SYSTEM

[0002] TECHNICAL FIELD

[0003] The present disclosure relates generally to the field of wireless communication. More particularly, it relates to methods, network node, first User Equipment, UE, second UE, and computer program products for relay communication in a wireless communication system.

[0004] BACKGROUND

[0005] Fifth generation or 5G New Radio, NR, network overcomes limitations of existing cellular networks by allowing for higher data rates, higher throughput, less latency, and less energy consumption and satisfying ever increasing traffic demand. Thereby, achieving improved network performance. The network performance improvement is achieved by the NR network using a number of advanced techniques, which comprise, for example, beamforming, massive multiple-input multiple-output, MIMO, full dimensional MIMO, FD-MIMO, advanced antenna array techniques, large-scale antenna techniques, or the like.

[0006] In NR, a User Equipment, UE, is allowed to connect to a network node using multi-path scenarios. In an example scenario 1, the UE (hereinafter referred to as remote UE) connects to the network node using a direct path and a Side Link, SL, relay path, which contains a SL backhaul and an access link, Uu, hop. In an example scenario 2, the remote UE connects to the network node using the direct path and a relay path, which contains an ideal backhaul / inter-UE connection and the Uu hop. In both the scenarios, the remote UE communicates with the network node via a relay UE on the relay path. A difference between the two scenarios is a backhaul link defined between the remote UE and the relay UE.

[0007] In the example scenario 2, aggregation of transmissions between the remote UE and the relay UE with the ideal backhaul / inter-UE connection on the relay path may be achieved.

[0008] In some examples, the transmissions between the remote UE and the relay UE may be aggregated at a Packet Data Convergence Protocol, PDCP, integrated at the ideal-backhaul / inter-UE connection. A basic framework for such an aggregation is supported in Third Generation Partnership Project, 3GPP, Release-18. In some examples, transmissions between the remote UE and the relay UE may be aggregated at a protocol layer below the PDCP of the remote UE. A basic framework for such an aggregation will be studied in upcoming 3GPP Release 19.

[0009] SUMMARY

[0010] An object of the present disclosure is to provide a method, a network node, first and second User Equipments, UEs, and a computer program product for relay communication in a wireless communication network, which mitigate, alleviate, or eliminate all or at least some of the drawbacks of presently known solutions.

[0011] This and other objects are achieved by means of a method, a network node, a first User Equipment, UE, a second UE, and a computer program product as defined in the appended claims. The term exemplary is in the present context to be understood as serving as an instance, example or illustration.

[0012] According to a first aspect of the present disclosure, a method performed by a network node for communicating with a first User Equipment, UE, via a relay path is provided. The method comprises configuring a second UE as a relay UE for the first UE on the relay path. The second UE is arranged between the first UE and the network node via a first link and a second link, respectively. The method comprises transmitting aggregation configuration information for each of the first UE and the second UE. At least a part of the aggregation configuration information is intended for use at each of the first UE and the second UE in configuring aggregation of transmissions between the first UE and the second UE in a protocol layer below a Packet Data Convergence Protocol, PDCP, layer of the first UE.

[0013] In some embodiments, the protocol layer below the PDCP layer of the first UE is a Medium Access Control, MAC, layer.

[0014] In some embodiments, the aggregation configuration information comprises at least one of: configurations of User Plane, UP, and Control Plane, CP, protocol stacks for the first link, configurations of UP and CP protocol stacks for the second link, a first set of configurations for the first UE, a second set of configurations for the second UE, one or more access link, Uu, identifiers, IDs associated with the first set of configurations and the second set of configurations, Uplink, UL, resources configured for transmission of at least one Transport Block, TB, from the first UE to the network node via the second UE on the relay path, and a fixed size for the at least one TB. The at least one TB corresponds to MAC Protocol Data Units, PDUs, of the first link.

[0015] In some embodiments, the first set of configurations for the first UE comprises at least one of: a radio bearer configuration for Radio Bearers, RBs, or services of the first UE mapped to the relay path, a configuration of each of upper protocol layers for the first UE, wherein the upper protocol layers comprise protocol layers for a Service Data Adaptation Protocol, SDAP, a PDCP, and a Radio Link Control, RLC, and a MAC layer configuration for the MAC layer in the first link.

[0016] In some embodiments, the second set of configurations for the second UE comprises at least one of: a physical layer configuration for a physical, PHY, layer in each of the first link and the second link, wherein the physical layer configuration is for channel processing of a Physical Data Shared Channel, PDCSH and a Physical Uplink Shared Channel, PUSCH on the relay path, a configuration to perform Hybrid Automatic Repeat Request, HARQ, processes on the relay path, and a MAC layer configuration for the MAC layer in each of the first link and the second link.

[0017] In some embodiments, the MAC layer configurations in the first set of configurations and the second set of configurations are the same or overlap with each other.

[0018] In some embodiments, the one or more Uu IDs associated with the first set and the second set of configurations are intended for services or logical channels of the first UE mapped to the relay path. The one or more Uu IDs being shared between the first UE and the second UE for transmissions and receptions on the relay path.

[0019] In some embodiments, at least one of the one or more Uu IDs associated with the first set and the second set of configurations comprises one or more of:

[0020] - a Cell Radio Network Temporary Identifier, C-RNTI, when the first UE and the second UE are enabled to identify a destination of the at least one TB when the at least one TB is to be transmitted towards or received from the network node; - a Configured Scheduling - RNTI, CS-RNTI, when the first UE and the second UE are performing transmissions towards or receptions from the network node on a Uu link using a semi-statically allocated resources by the network node;

[0021] - a resume ID or an Inactive RNTI, l-RNTI for the HARQ processes on the relay path, when the first UE and / or the second UE switch from an Radio Resource Control, RRC, inactive state to a RRC connected state, said resume ID or l-RNTI being used to determine a UE context associated with the first UE and / or the second UE;

[0022] - an UE ID of the first UE, when a radio channel quality of the direct path between the first UE and the network node is greater than a radio channel quality of the second link between the second UE and the network node; and

[0023] - an UE ID of the second UE, when the radio channel quality of the second link between the second UE and the network node is greater than the radio channel quality of the direct path between the first UE and the network node, wherein the UE IDs of the first UE and the second UE have been assigned by at least one of: the network node, the first UE, and the second UE.

[0024] In some embodiments, the at least the part of the aggregation configuration information is intended to cause the first UE to perform a first set of functions at the first link. The first set of functions comprising at least one of: building the at least one TB based on at least one of: the Uu IDs and the fixed size of the at least one TB and forwarding the at least one TB to the second UE over the first link. The at least one TB is to be transmitted to the network node via the second UE on the relay path.

[0025] In some embodiments, the at least the part of the aggregation configuration information is intended to cause the second UE to perform at least a second set of functions at the first link and the second link on the relay path. The second set of functions comprising at least one of the following:

[0026] - performing the HARQ processes on the relay path by managing at least a part of functions of the HARQ processes at the MAC layer and the PHY layer in the second link; - transmitting the at least one TB received from the first UE to the network node over the second link, in accordance with at least one of: the UL resources configured for the transmission of the at least one TB and the fixed size determined for the at least one TB;

[0027] - mapping each of the at least one TB received from the first UE to one of HARQ entities to operate transmissions and retransmissions of the at least one TB over the second link;

[0028] - performing channel processing of the PDSCH and the PUSCH on the relay path; and

[0029] - signaling of a HARQ feedback to the network node over the second link.

[0030] In some embodiments, the second set of functions further comprising at least one of the following:

[0031] - providing at least one service to the upper protocol layers in the second link, said at least one service comprising data transferring to the upper protocol layers and radio resource allocation;

[0032] - mapping between logical and transport channels for the transmissions and the receptions on the relay path;

[0033] - multiplexing of MAC Service Data Units, SDUs onto the at least one TB;

[0034] - de-multiplexing of the MAC SDUs from the at least one TB;

[0035] - reporting a schedule of the transmissions on the relay path to the network node;

[0036] - performing error correction of the transmissions through the HARQ processes; and

[0037] - prioritizing the logical channels on the relay path.

[0038] In some embodiments, the aggregation configuration information further comprises a configuration for an adaptation layer to be implemented at the first link on the relay path. Said configuration causes the adaptation layer to perform one or more of: adapting a difference between the second and first set of functions performed by the second and first UEs to achieve the transmissions and the receptions over the first link and the second link, and managing a difference of functions between different vendors providing the first UE and the second UE. The aggregation configuration information further comprises a configuration for an adaptation layer to be implemented at the second link on the relay path.

[0039] In some embodiments, the step of transmitting the aggregation configuration information comprises transmitting, to the first UE over the direct path, the aggregation configuration information, wherein the aggregation configuration information is transmitted by the first UE to the second UE over the first link. In some embodiments, the step of transmitting the aggregation configuration information comprises transmitting directly, to the first UE and the second UE, the aggregation configuration information.

[0040] In some embodiments, the step of configuring the second UE as the relay UE for the first UE is preceded by the steps of receiving a first report related to the first UE. The first report comprising at least one of: assistance information, measurement results, and a request for aggregating transmissions between the first UE and the relay UE on the relay path. The method comprises determining in accordance with the first report, whether to enable the requested aggregation for the first UE on the relay path. When it has been determined to enable the requested aggregation for the first UE on the relay path, the method comprises determining, from the first report, at least one second UE being operable as the relay UE for the first UE. The method comprises receiving a second report related to each of the determined at least one second UE. The second report comprising capability information and measurement results related to each of the at least one second UE. The method comprises selecting in accordance with evaluation of the second report, the second UE from the at least one second UE as the relay UE for the first UE.

[0041] In some embodiments, the first report related to the first UE comprises the assistance information identifying at least one of: Quality of Service, QoS, requirements associated with the services of the first UE and traffic pattern characteristics and buffer status of the first UE. The first report further comprises the measurement results, each measurement result indicating a radio channel quality of the first link between the first UE and one of the at least one second UE.

[0042] In some embodiments, the second report related to each of the at least one second UE comprises the capability information indicating whether the second UE is operable as the relay UE when it is determined to enable the requested aggregation for the first UE. The second report further comprises the measurement results indicating a radio channel quality of each of the first link between the first UE and the second UE and the second link between the second UE and the network node.

[0043] In some embodiments, the first link is an inter-UE interface and the second link is a Uu interface. According to a second aspect of the present disclosure, a method performed by a first User Equipment, UE, for managing a communication with a network node via a second UE on a relay path is provided. The second UE being arranged between the first UE and the network node using via a first link and a second link, respectively. The method comprises receiving aggregation configuration information. Based on at least a part of the received aggregation configuration information, the method comprises configuring aggregation of transmissions between the first UE and the second UE in a protocol layer below a Packet Data Convergence Protocol, PDCP, layer of the first UE and performing a first set of functions at the first link.

[0044] According to a third aspect of the present disclosure, a method performed by a second User Equipment, UE, for managing a communication between a first UE and a network node on a relay path is provided. The second UE being arranged between the first UE and the network node via a first link and a second link, respectively. The method comprises receiving, from one of the network node and the first UE, aggregation configuration information. Based on at least a part of the aggregation configuration information, the method comprises configuring aggregation of transmissions between the first UE and the second UE in a protocol layer below a Packet Data Convergence Protocol, PDCP, layer of the first UE and performing a second set of functions at the first link and the second link.

[0045] According to a fourth aspect of the present disclosure, an apparatus of a network node configured for communicating with a first User Equipment, UE, via a relay path is provided. The apparatus comprises a controlling circuitry configured to cause configuration of a second UE as a relay UE for the first UE on the relay path. The second UE is arranged between the first UE and the network node via a first link and a second link, respectively. The controlling circuitry is configured to cause transmission of aggregation configuration information for each of the first UE and the second UE. At least a part of the aggregation configuration information is intended for use at each of the first UE and the second UE in configuring aggregation of transmissions between the first UE and the second UE in a protocol layer below a Packet Data Convergence Protocol, PDCP, layer of the first UE.

[0046] A fifth aspect is a network node comprising the apparatus of the fourth aspect. According to a sixth aspect of the present disclosure, a first User Equipment, UE, configured for managing a communication with a network node via a second UE on a relay path is provided. The second UE being arranged between the first UE and the network node using via a first link and a second link, respectively. The first UE comprises a controlling circuitry configured to cause reception of aggregation configuration information. Based on at least a part of the received aggregation configuration information, the method comprises configuring aggregation of transmissions between the first UE and the second UE in a protocol layer below a Packet Data Convergence Protocol, PDCP, layer of the first UE and performing a first set of functions at the first link.

[0047] According to a seventh aspect of the present disclosure, a second User Equipment, UE, configured for managing a communication between a first UE and a network node on a relay path is provided. The second UE being arranged between the first UE and the network node via a first link and a second link, respectively. The second UE comprises a controlling circuitry configured to cause reception of aggregation configuration information from one of the network node and the first UE. Based on at least a part of the aggregation configuration information, the controlling circuitry is further configured to cause configuring aggregation of transmissions between the first UE and the second UE in a protocol layer below a Packet Data Convergence Protocol, PDCP, layer of the first UE and performing of a second set of functions at the first link and the second link.

[0048] According to an eighth aspect of the present disclosure, there is provided a computer program product comprising a non-transitory computer readable medium, having thereon a computer program comprising program instructions. The computer program is loadable into a data processing unit and configured to cause execution of the method according to any of the first to third aspects when the computer program is run by the data processing unit.

[0049] In some embodiments, any of the above aspects may additionally have features identical with or corresponding to any of the various features as explained above for any of the other aspects.

[0050] An advantage of some embodiments is that alternative and / or improved approaches are provided for achieving aggregation of transmissions between a first UE and a second UE at a protocol layer below a PDCP layer of the first UE. Such an aggregation may provide lower resource consumption, higher throughput, higher reliability, and lower latency, compared to aggregation of transmissions between the first UE and the second UE at the PDCP layer.

[0051] An advantage of some embodiments is that with the aggregation of transmissions between the first UE and the second UE at the protocol layer below the PDCP layer of the first UE, transmissions and receptions may be performed on the relay path with improved uplink and downlink capability and reliability.

[0052] An advantage of some embodiments is that Uu links of multiple UEs may be aggregated to produce higher data rate and more reliable transmissions or receptions between the multiple UEs and the network node.

[0053] An advantage of some embodiments is that a first link / inter-UE interface provided between the first UE and the second UE comprises an ideal backhaul with low latency and high throughput. Such an ideal backhaul may aid in achieving faster delivery of data transmissions.

[0054] An advantage of some embodiments is that sharing one or more Uu IDs between the first UE and the second UE on the relay path enables the second UE to maintain only a minimum set of LI and L2 functions corresponding to LI and L2 layers, respectively.

[0055] BRIEF DESCRIPTION OF THE DRAWINGS

[0056] The foregoing will be apparent from the following more particular description of the example embodiments, as illustrated in the accompanying drawings in which like reference characters refer to the same parts throughout the different views. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating the example embodiments.

[0057] Figs 1A-1D show example concepts disclosed in Third Generation Partnership Project, 3PPP specification.

[0058] Fig. 1A discloses a user plane stack for a Layer 2, L2, User Equipment, UE-to-Network Relay UE, according to 3GPP TR 23.752 23.752 version 17.0.0;

[0059] Fig. IB discloses a control plane stack for a L2 UE-to Network Relay UE according to 3GPP TR 23.757 23.752 version 17.0.0; Fig. 1C discloses a L2 structure for downlink, DL, with Carrier Aggregation, CA, configured according to 3GPP TS 38.300 version 17.5.0;

[0060] Fig. ID discloses a L2 structure for uplink, UL, with CA configured according to 3GPP TS 38.300 version 17.5.0;

[0061] Fig. 2 discloses an example wireless communication network;

[0062] Fig. 3 discloses an example wireless communication network for relay communication;

[0063] Fig. 4A discloses an example user plane protocol stack for each of a first link between a first UE and second a UE and a second link between the second UE and a network node;

[0064] Fig. 4B discloses an example control plane protocol stack for each of a first link between a first

[0065] UE and second a UE and a second link between the second UE and a network node;

[0066] Fig. 5A is a signaling diagram illustrating example signaling for achieving aggregation of transmissions between a first UE and a second UE at a protocol layer below a Packet Data Convergence Protocol, PDCP, layer of the first UE;

[0067] Fig. 5B is a signaling diagram illustrating example signaling for releasing of enabled aggregation of transmissions between a first UE and a second UE at a protocol layer below a PDCP layer of the first UE;

[0068] Figs. 6A, 6B, and 6C disclose transmission of aggregation configuration information for each of a first UE and a second UE according to some examples;

[0069] Fig. 7 discloses an example illustration of handling relay communication in a wireless communication network while achieving aggregation of transmissions between a first UE and a second UE at a protocol layer below a PDCP layer of the first UE;

[0070] Fig. 8 is a flowchart illustrating example method steps of a method performed for communicating with a first UE via a relay path;

[0071] Fig. 9 is a flowchart illustrating example method steps of a method performed for communicating with a network node via a second UE on a relay path; Fig. 10 is a flowchart illustrating example method steps of a method performed for managing communication between a first UE and a network node on a relay path;

[0072] Fig. 11 is a schematic block diagram illustrating an example apparatus;

[0073] Fig. 12 is a schematic block diagram illustrating an example apparatus;

[0074] Fig. 13 is a schematic block diagram illustrating an example apparatus;

[0075] Fig. 14 is a block diagram of a telecommunication network connected via an intermediate network to a host computer, according to some examples;

[0076] Fig. 15 is a block diagram of a host computer communicating via a base station with a UE over a partially wireless connection, according to some examples;

[0077] Fig. 16 is a block diagram of example methods implemented in a communication system including a host computer, a base station, and a UE;

[0078] Fig. 17 is a block diagram of example methods implemented in a communication system including a host computer, a base station, and a UE;

[0079] Fig. 18 is a block diagram of example methods implemented in a communication system including a host computer, a base station, and a UE;

[0080] Fig. 19 is a block diagram of example methods implemented in a communication system including a host computer, a base station, and a UE; and

[0081] Fig. 20 discloses an example computing environment.

[0082] DETAILED DESCRIPTION

[0083] Aspects of the present disclosure will be described more fully hereinafter with reference to the accompanying drawings. The apparatus and methods disclosed herein can, however, be realized in many different forms and should not be construed as being limited to the aspects set forth herein. Like numbers in the drawings refer to like elements throughout.

[0084] Embodiments of the present disclosure will be described and exemplified more fully hereinafter with reference to the accompanying drawings. The solutions disclosed herein can, however, be realized in many different forms and should not be construed as being limited to the embodiments set forth herein.

[0085] It will be appreciated that when the present disclosure is described in terms of a method, it may also be embodied in one or more processors and one or more memories coupled to the one or more processors, wherein the one or more memories store one or more programs that perform the steps, services and functions disclosed herein when executed by the one or more processors.

[0086] Generally, all terms used herein are to be interpreted according to their ordinary meaning in the relevant technical field, unless a different meaning is clearly given and / or is implied from the context in which it is used. All references to a / an / the element, apparatus, component, means, step, etc. are to be interpreted openly as referring to at least one instance of the element, apparatus, component, means, step, etc., unless explicitly stated otherwise. The steps of any methods and / or procedures disclosed herein do not have to be performed in the exact order disclosed, unless a step is explicitly described as following or preceding another step and / or where it is implicit that a step must follow or precede another step. Any feature of any of the embodiments disclosed herein can be applied to any other embodiment, wherever appropriate. Likewise, any advantage of any of the embodiments can apply to any other embodiments, and vice versa. Other objectives, features and advantages of the enclosed embodiments will be apparent from the following description.

[0087] Furthermore, the following terms are used throughout the description given below:

[0088] - User Equipment: As used herein, a "UE" is a non-limiting term and refers to any type of wireless device that has access to (i.e., is served by) a wireless communication network by communicating wirelessly with network nodes and / or other wireless devices. Communicating wirelessly can involve transmitting and / or receiving wireless signals using electromagnetic waves, radio waves, infrared waves, and / or other types of signals suitable for conveying information through air. Some examples of a wireless device include, but are not limited to, smart phones, mobile phones, cell phones, voice over IP, VoIP, phones, wireless local loop phones, desktop computers, personal digital assistants, PDAs, wireless cameras, gaming consoles or devices, music storage devices, playback appliances, wearable devices, wireless endpoints, mobile stations, tablets, laptops, laptop-embedded equipment, LEE, laptop-mounted equipment, LME, smart devices, wireless customer-premise equipment, CPE, mobile-type communication, MTC, devices, Universal Serial Bus, USB, dongles, Internet-of-Things, loT, devices, vehicle-mounted wireless terminal devices, D2D UEs, V2X UEs, etc. Unless otherwise noted, the term "UE" is used interchangeably herein with the term "wireless device".

[0089] - Network Node: As used herein, a "network node" is any node that is part of a radio access network. Functionally, a network node is equipment capable, configured, arranged, and / or operable to communicate directly or indirectly with a UE and / or with other network nodes or equipment in the cellular communications network, to enable and / or provide wireless access to the UE, and / or to perform other functions (e.g., administration) in a cellular communications network. Examples of the network node include, but are not limited to, a radio access network, RAN, a NodeB, a MeNB, a SeNB, a network node belonging to a master cell group, MCG, or a secondary cell group, SCG, a base station, BS, and a multi-standard radio, MSR, a radio node such as a MSR BS, an eNodeB, a gNodeB, a network controller, a radio network controller, RNC, a base station controller, BSC, a relay, a donor node controlling relay, a base transceiver station, BTS, a Central Unit, CU, (for example, in a gNB), Distributed Unit, DU (for example, in a gNB), Baseband Unit, BBU, Centralized BaseBand, C-RAN, access points, APs, transmission points, transmission nodes, a remote radio unit, RRU, and a remote radio head, RRH, nodes in distributed antenna system, DAS, a core network node (for example, a mobile switching center, MSC, a mobility management entity, MME, or the like), an operation & management, O&M, node, an operations support system, OSS, node a self-optimized network, SON, a positioning node (for example, an evolved serving mobile location center, E-SMLC), a minimization drive test, MDT, test equipment (for example, a physical node or software), and so on

[0090] In some embodiments, generic terminology, "radio network node" or simply "network node, NW" may be used. It can be any kind of network node, which may comprise base station, radio base station, base transceiver station, base station controller, network controller, eNB, gNB, relay node, Access Point, AP, radio AP, RRU, RRH, CU, DU, BU, C-RAN, access point, and so on.

[0091] - Direct path: As used herein, "direct path" refers to a direct connection between a remote UE and a network node. - Relay path / lndirect path: As used herein, "relay / indirect path" is an indirect connection between the remote UE and the network node via an intermediate node referred as a relay UE.

[0092] - Upper layer aggregation: As used herein "upper layer aggregation" refers to aggregation of transmissions between two UEs (a remote / first UE and a relay / second UE) at a Packet Data Convergence Protocol, PDCP, layer;

[0093] - Lower layer aggregation / Ll / L2 layer aggregation: As used herein "lower layer aggregation" refers to aggregation of transmissions between two UEs (a remote / first UE and a relay / second UE) at a protocol layer below a PDCP layer of the remote / first UE.

[0094] Note that the description given herein focuses on a 3GPP cellular communications system and, as such, 3GPP terminology or terminology similar to 3GPP terminology is generally used. However, the concepts disclosed herein are not limited to a 3GPP system. Other wireless systems, including without limitation Wide Band Code Division Multiple Access, WCDMA, Worldwide Interoperability for Microwave Access, WiMax, Ultra Mobile Broadband, UMB, and Global System for Mobile Communications, GSM, may also benefit from the concepts, principles, and / or embodiments described herein.

[0095] In addition, functions and / or operations described herein as being performed by a wireless device or a network node may be distributed over a plurality of wireless devices and / or network nodes. Furthermore, although the term "cell" is used herein, it should be understood that (particularly with respect to 5G NR and beyond) beams may be used instead of cells and, as such, concepts described herein apply equally to both cells and beams.

[0096] As mentioned above, Figs. 1A-1D illustrate example concepts disclosed in Third Generation Partnership Project, 3PPP specification.

[0097] In NR, a User Equipment, UE, (hereinafter referred as remote UE) is allowed to communicate with a network node via a direct path and via a relay path. In the direct path, the remote UE communicates with the network node via a direct connection, for example access link, Uu, interface. In the relay path, the remote UE communicates with the network node via a relay UE. The relay UE acts as an intermediate node between the remote UE and the network node via an ideal backhaul / inter-UE connection and the Uu interface, respectively. In Third Generation Partnership Project, 3GPP, Release-18, it is interpreted that that the remote UE establishes / maintains the relay path by reusing L2 UE-to-Network, U2N, relay solutions. In the L2 U2N relay solutions, the relay UE (referred as L2 UE-to-Network Relay UE) provides a forwarding functionality for relaying any type of traffic over a PC5 link. The PC5 link may be an interface between two devices for device-to-device communication. The L2 UE-to-Network Relay UE also provides a functionality to support connectivity to a Fifth Generation, 5G, system, 5GS for the remote UE(s). In the L2 U2N relay solutions, the remote UE may be a UE, which has been successfully established the PC5 link to the L2 UE-to-Network Relay UE. The remote UE can be located within New Generation, NG, Radio Access Network, RAN, NG-RAN, coverage or outside of the NG-RAN coverage.

[0098] Fig. 1A discloses an example user plane protocol stack related to a Packet Data Unit, PDU, session, including a L2 UE-to-Network Relay UE.

[0099] As disclosed in Fig. 1A, the user plane protocol stack comprises a PDU layer at a remote UE. The PDU layer corresponds to PDU carried between the remote UE and a Data Network, DN, over the PDU session. Further, the user plane protocol stack comprises two endpoints of Packet Data Convergence Protocol, PDCP, link. The two endpoints of the PDCP link are the remote UE and a network node. A relay function is performed below a PDCP layer of the remote UE. Performing the relay function below the PDCP layer ensures data security between the remote UE and the network node without exposing raw data at the L2 UE-to-Network Relay UE.

[0100] The user plane protocol stack disclosed in Fig. 1A further comprises an adaptation relay layer within the L2 UE-to-Network Relay UE. The adaptation relay layer can differentiate between Signaling Radio Bearers, SRBs and Data Radio Bearers, DRBs, for a particular remote UE. The adaptation layer is also responsible for mapping PC5 trafficto one or more DRBs of a Uu interface. The adaptation layer is disclosed in 3GPP TSG RAN WG2.

[0101] Fig. IB discloses a protocol stack of Non-Access Stratum, NAS, connection for a remote UE to a NAS-Mobility Management, MM, and NAS-Session Management, SM. In the NAS connection, NAS messages are transparently transferred between a remote UE and a 5G-Access Network, 5G- AN, over a L2 UE-to-Network Relay UE using: - Packet Data Convergence Protocol, PDCP, end-to-end connection, where a role of the L2 UE- to-Network Relay UE is to relay Packet Data Units, PDUs, over a signaling radio bearer without any modifications;

[0102] - N2 connection between the 5G-AN and an Access Management Function, AMF over N2; and

[0103] - Nil connection AMF and SMF over Nil.

[0104] Herein, a role of the L2 UE-to-Network Relay UE is to relay the PDUs from the signaling radio bearer without any modifications.

[0105] In the L2 U2N solutions, as described in Figs. 1A and IB, for each radio bearer mapped to the relay path, the remote UE and the network node maintain respective PDCP entities. Such an operation may enable aggregation of transmissions between the remote UE and the L2 UE-to- Network Relay at the PDCP layer of the remote UE (referred to as upper layer aggregation). The L2 UE-to-Network Relay performs a relay functionality below the PDCP layer of the remote UE. Thus, the upper layer aggregation may be achieved by applying dual connectivity similar solutions.

[0106] Similarly, the transmissions between the remote UE and the relay UE can be aggregated at a protocol layer below the PDCP of the remote UE (referred to as lower layer aggregation). In some examples, the lower layer aggregation may be achieved by applying Carrier Aggregation, CA, similar solutions.

[0107] However, the CA similar solutions do not describe any procedures and details on protocol stacks to achieve / support aggregation of the transmissions between the remote UE and the relay UE at the protocol layer below the PDCP layer of the remote UE.

[0108] Figs. 1C and ID disclose a Layer 2, L2, structure for downlink, DL, and Uplink, UL, in a Uu Carrier Aggregation, CA, framework.

[0109] The Uu CA framework may be used as a baseline for achieving aggregation of transmissions between a remote UE and a relay UE in a layer below a Packet Data Convergence Protocol, PDCP layer of the remote UE (such an aggregation may be hereinafter referred to as lower layer aggregation). However, in order to achieve the lower layer aggregation, at least, the following drawbacks are to be expected (as disclosed in Figs. 1C and ID):

[0110] - in case of using the Uu CA framework, a multi-carrier nature of a Physical, PHY, layer is only exposed to a Medium Access Control, MAC, layer for which one Hybrid Automatic Repeat Request, HARQ, entity is required per serving cell; and

[0111] - in both the UL and the DL, there is one independent HARQ entity per serving cell and one transport block is generated per assignment / grant per serving cell in the absence of spatial multiplexing. Each transport block and its potential HARQ retransmissions are mapped to a single serving cell.

[0112] Consequently, there is a need to provide an essential framework for the lower layer aggregation.

[0113] Fig. 2 discloses an example wireless communication system 200. Although the subject matter described herein may be implemented in any appropriate type of system using any suitable components, the examples disclosed herein are described in related to the wireless communication system 200 (also be referred to as wireless communication network). The wireless communication system 200 may comprise and / or interface with any type of communication, telecommunication, data, cellular, and / or radio network or other similar type of system. In some examples, the wireless communication system 200 may be configured to operate according to specific standards or other types of predefined rules of procedures. Thus, particular examples of the wireless communication system 200 may implement communication standards / Radio Access Technologies, RATs, such as, but are not limited to, global system for mobile communications, GSM, universal mobile telecommunications system, UMTS, long term evolution, LTE, and / or other suitable 2G, 3G, 4G, or 5G standards, wireless local area network, WLAN, standards such as, IEEE 802.11 standards, and / or any other appropriate wireless communication standards, such as, worldwide interoperability for microwave access, WiMax, Bluetooth, Z-Wave and / or ZigBee standards. The wireless communication system 200 may provide communication and other type of services to one or more wireless devices to facilitate the wireless devices' access to and / or use of the services provided by, or via, the wireless communication system 200. For simplicity, as disclosed in Fig. 2, the wireless communication system 200 comprises a network node 202 and a plurality of User Equipments, UEs 204-1 - 204-N.

[0114] The network node 202 refers to equipment capable, configured, arranged, and / or operable to communicate with the UEs 204-1 - 204-N and / or with other network nodes or equipment in the wireless communication system 200 to enable and / or provide wireless access to UEs 204-1 - 204- N and / or to perform other functions (for example, administration) in the wireless communication system 200.

[0115] A UE of the plurality of UEs 204-1 - 204-N refers to a device capable, configured, arranged and / or operable to communicate wirelessly with the network node 202 and / or other UEs. Unless otherwise noted, the term "UE" may be used interchangeably herein with "wireless device". Communicating wirelessly may involve transmitting and / or receiving wireless signals using electromagnetic waves, radio waves, infrared waves, and / or other types of signals suitable for conveying information through air.

[0116] The UE of the plurality of UEs 204-1 - 204-N is allowed to communicate with the network node via a direct path or a relay path. For example, as disclosed in Fig. 2, a UE 204-1 is capable of communicating with the network node 202 using an access link, Uu, interface on the direct path 206. Also, the UE 204-1 is capable of communicating with the network node 202 through another UE (for example, a UE 204-2) on the relay path 208.

[0117] In some examples, when the UE 204-1 is communicating with the network node 202 through the UE 204-2 on the relay path 208, transmissions between the UE 204-1 and the UE 204-2 may be aggregated at a Packet Data Convergence Protocol, PDCP, layer of the UE 204-1 (hereinafter referred as upper layer aggregation). Further, the UE 204-2 may apply a relay functionality below the PDCP layer to relay the aggregated transmissions to the network node 202 on the relay path 208. For the upper layer aggregation, the UE 204-1 and the network node 202 have to maintain respective PDCP entities corresponding to the PDCP layer. A framework for the upper layer aggregation is disclosed in 3GPP Release 18.

[0118] In some examples, when the UE 204-1 is communicating with the network node 202 through the UE 204-2 on the relay path 208, transmissions between the UE 204-1 and the UE 204-2 may be aggregated at a protocol layer below the PDCP layer of the UE 204-1 (hereinafter referred as lower layer aggregation). The lower layer aggregation may be activated using a Uu Carrier Aggregation, CA, framework as baseline. However, in case of the CA, a multi-carrier nature of a Physical, PHY, layer is only exposed to a MAC layer for which one Hybrid Automatic Repeat Request, HARQ, entity is required per serving cell. Further, in both the UL and the DL, there is one independent HARQ entity per serving cell and one transport block is generated per assignment / grant per serving cell in the absence of spatial multiplexing. Each transport block and its potential HARQ retransmissions are mapped to a single serving cell.

[0119] Therefore, the CA framework does not provide any procedures or details on protocol stacks or other configurations to be used for the lower layer aggregation.

[0120] Therefore, the network node 202 herein implements a method to communicate with a UE, for example, UE 204-1 via a relay path 208, by achieving the lower layer aggregation. Hereinafter, the UE 204-1 is referred as a first UE 204-1. The term "first UE" may be used interchangeably herein with "remote UE", "target UE", "aggregated UE", or the like.

[0121] For communicating with the first UE 204-1 via the relay path 208, the network node 202 configures a second UE, for example, UE 204-2 among the plurality of UEs 204-1 - 204-N, as a relay UE for the first UE 204-1 on the relay path 208. The term "second UE" may be used interchangeably herein with "relay UE", "anchor UE", "assisting UE", or the like. Although the method implemented by the network node 202 is applicable for the plurality of UEs 204-1 - 204- N, examples herein consider the UE 204-1 as the first UE and the UE 204-2 as the second UE for ease of understanding.

[0122] The second UE 204-2 is arranged between the first UE 204-1 and the network node 202 via a first link and a second link, respectively. In some examples, the first link may be an inter-UE interface (also be referred to as inter-UE connection) and the second link may be a Uu interface. The term "first link" may be used interchangeably herein with "inter-UE interface", "inter-UE connection", "ideal backhaul", or the like. The term "second link" may be used interchangeably herein with "Uu link", "Uu interface", or the like. Upon configuring the second UE 204-2 for the first UE 204-1 as the relay UE, the network node 202 transmits aggregation configuration information for each of the first UE 204-1 and the second UE 204-2. At least a part of the aggregation configuration information is intended for use at each of the first UE 204-1 and the second UE 204-2 in configuring aggregation of transmissions between the first UE 204-1 and the second UE 204-2 in a protocol layer below a PDCP layer of the first UE 204-1. Thereby, the lower layer aggregation is achieved, which provides lower resource consumption, higher throughput, higher reliability, and lower latency compared to the upper layer aggregation.

[0123] Various examples for handling the relay communication in the wireless communication, while achieving the lower layer aggregation are explained in conjunction with figures in the later parts of the description.

[0124] Fig. 3 discloses an example wireless communication system 200 for relay communication. The wireless communication system 200 comprises a first User Equipment, UE 204-1, a second UE 204-2, a Radio Access Network, RAN, 301, a Core Network, CN, 302, and an Application Server, AS, 304.

[0125] The RAN 301 comprises one or more network nodes 202, each providing radio coverage over one or more geographical areas. In some examples, the network node 202 may be a radio access node such as a radio network controller, an access point such as a Wireless Local Area Network, WLAN, access point or an Access Point Station, AP STA, an access controller, a base station, a base transceiver station, an Access Point base station, a base station router, a transmission arrangement of a radio base station, a standalone access point, or any other unit of the RAN capable of serving one or more UEs in the cell / service area. Examples of the base station may include, a gNodeB, gNB, an evolved Node B, eNB, and so on.

[0126] The CN 302 comprises a core network node for implementing network functions of the CN 302. For example, if the CN 302 comprises a 5G CN, 5GC, the CN may include the core network node implementing network functions of the CN 302 such as but are not limited to, an Access and Mobility Function, AMF, a User Plane Function, UPF, a Session Management Function, SMF, an Authentication Server Function, AUSF, a Network Slice Selection Function, NSSF, a Network Exposure Function, NEF, a Network Repository Function, NRF, a Policy Control Function, PCF, a Unified Data Management, UDM, and so on.

[0127] The AS 304 implements an Application Function, AF, within the CN 302. The AF provides application services to subscribed UEs.

[0128] The first and second UEs 204-1 and 204-2 communicate with the network node 202 via a direct path and a relay path. For simplicity, the relay path is illustrated in Fig. 3.

[0129] The network node 202 may initially start communicating with the first UE 204-1 via the direct path. Thereafter, the network node 202 decides to communicate with the first UE 204-1 via relay path and further decides to enable aggregation of transmissions between the first UE 204-1 and a relay UE on a relay path at a protocol layer below a Packet Data Convergence Protocol, PDCP, layer of the first UE 204-1 (referred hereinafter as lower layer aggregation). The protocol layer below the PDCP layer of the first UE 204-1 may be a Medium Access Control, MAC, layer.

[0130] The network node 202 may decide to enable the lower layer aggregation based on one or more parameters associated with the first UE 204-1. Examples of the parameters may include, but are not limited to, uplink radio channel quality, traffic pattern characteristics, uplink transmission power, Quality of Service, QoS, of services or the like, associated with the first UE 204-1.

[0131] Consider an example scenario, wherein the first UE 204-1 may not able to transmit data to the network node due to shortage of uplink transmission power. In such a scenario, if the lower layer aggregation is enabled, the first UE 204-1 may transmit the data to the network node 202 via the relay path while configuring the lower layer aggregation. Due to which, the data may be transmitted from the first UE 204-1 to the network node 202 via the relay path without any failure.

[0132] In some examples, the services being accessed by the first UE 204-1 from the network node 202 may be associated with critical requirements. Consider an example scenario, wherein a service is associated with a delay critical requirement. In such a scenario, if the network node 202 enables the lower layer aggregation for the first UE 204-1, the first UE 204-1 transmits data of the service to the network node 202 via the relay path while configuring the lower layer aggregation. Such a relay communication may be beneficial to reduce transmission latency for the data, since the relay path provides better connection than the direct path. Consider another example scenario, wherein the service is associated with non-critical QoS requirements. In such a scenario, if the first UE 204-1 transmits data of the service to the network node 202 via the relay path while configuring the lower layer aggregation, it may be beneficial to offload the direct path / connection.

[0133] In some examples, the network node 202 may decide to enable the lower layer aggregation for the first UE 204-1, when the lower layer aggregation has been requested by the first UE 204-1. The first UE 204-1 may transmit a first report to the network node 202. The first report may comprise at least one of: assistance information, measurement results, and a request for aggregating transmissions between the first UE 204-1 and the relay UE on the relay path. In some examples, the assistance information may identify at least one of: QoS requirements associated with the services, traffic pattern characteristics and a buffer status of the first UE 204-1. In some examples, each measurement result may indicate a radio channel quality of the first link 306 between the first UE 204-1 and one of at least one second UE. The at least one second UE may operable as the relay UE for the first UE 204-1. In accordance with evaluation of the first report, the network node 202 may determine whether to enable the lower layer aggregation for the first UE 204-1 on the relay path.

[0134] Upon determining to enable the lower layer aggregation for the first UE 204-1, the network node 202 may determine, from the first report, the at least one second UE, which may operable as the relay UE for the first UE 204-1. After determining the at least one second UE, the network node 202 may instruct the at least one second UE to send a second report. The network node 202 may receive the second report from each of the at least one second UE. The second report may comprise capability information and measurement results related to each of the at least one second UE. In some examples, the capability information of a second UE may indicate whether the second UE is operable as the relay UE for the first UE 204-1. In some examples, the measurement results related to the second UE may indicate a radio channel quality of each of a first link between the first UE 204-1 and the second UE and a second link between the second UE and the network node 202. In accordance with evaluation of the second report from each of the at least one second UE, the network node 202 may select the second UE 204-2 from the at least one second UE.

[0135] The network node 202 configures the selected second UE 204-2 as the relay UE for the first UE 204-1 on the relay path. The second UE 204-2 is arranged between the first UE 204-1 and the network node 202 via a first link 306 and a second link 308. Thus, the relay path herein comprises two hops. A first hop is between the first UE 204-1 and the second UE 204-2 using the first link 306. A second hop is between the second UE 204-2 and the network node 202 using the second link 308.

[0136] The first link may be an inter-UE interface and the second link may be an access link, Uu interface. The inter-UE interface may be an ideal backhaul link with low latency and high throughput. In some examples, the ideal backhaul link may be connection in any form including Ethernet, cable fiber, wireless connection including WiFi, Uu, Side Link, SL, Bluetooth, Zigbee, or the like.

[0137] After configuring the second UE 204-2 as the relay UE for the first UE 204-1, the network node 202 transmits aggregation configuration information for each of the first UE 204-1 and the second UE 204-2. At least a part of the aggregation configuration information is intended for use at each of the first UE 204-1 and the second UE 204-2 in configuring aggregation of transmissions between the first UE 204-1 and the second UE 204-2 in a protocol layer below a PDCP layer of the first UE 204-1. Thereby, the network node 202 may communicate with the first UE 204-1 via the relay path, while achieving the lower layer aggregation at the first UE 204-1 on the relay path.

[0138] In some examples, the network node 202 may transmit the aggregation configuration information directly to the first UE 204-1 and the second UE 204-2. In some examples, the network node 202 may transmit the aggregation configuration information to the first UE 204-1 over the direct path / Uu interface. The first UE 204-1 may further transmit the received aggregation information to the second UE 204-2 over the first link 306. As would be understood, the second UE 204-2 or the first UE 204-1 may transmit at least a part of the aggregation configuration information between each other according to some examples.

[0139] In some examples, the aggregation configuration information may comprise at least one of: configurations of User Plane, UP, and Control Plane, CP, protocol stacks for the first link 306, configurations of UP and CP protocol stacks for the second link 308, a first set of configurations for the first UE 204-1, a second set of configurations for the second UE 204-2, one or more access link, Uu, identifiers, IDs associated with the first set of configurations and the second set of configurations, Uplink, UL, resources configured for transmission of at least one Transport Block, TB, from the first UE 204-1 to the network node 202 via the second UE 204-2 on the relay path, and a fixed size for the at least one TB. The at least one TB referred to herein may correspond to MAC Protocol Data Units, PDUs, of the first link 306. The UP and CP stacks provided for the first link 306 and the second link 308 are described in detail in conjunction with Figs. 4A and 4B.

[0140] The first set of configurations for the first UE 204-1 may comprise at least one of: a radio bearer configuration for Radio Bearers, RBs, or services of the first UE 204-1 mapped to the relay path, a configuration of each of upper protocol layers for the first UE 204-1, and a MAC layer configuration for the MAC layer in the first link 306. The upper protocol layers may comprise protocol layers for a Service Data Adaptation Protocol, SDAP, a PDCP, and a Radio Link Control, RLC.

[0141] The second set of configurations for the second UE 204-2 may comprise at least one of: a physical layer configuration for a Physical, PHY, layer in each of the first link 306 and the second link 308, a configuration to perform Hybrid Automatic Repeat Request, HARQ, processes / operations on the relay path, and a MAC layer configuration for the MAC layer in each of the first link 306 and the second link 308. The physical layer configuration may be used for channel processing of a Physical Data Shared Channel, PDCSH and a Physical Uplink Shared Channel, PUSCH on the relay path 208. In the context of this disclosure, the PDSCH may comprise downlink data from the network node 202 and the PUSCH may comprise the at least one TB of the first UE intended for the network node 202.

[0142] In some examples, the MAC layer configurations in the first set of configurations and the second set of configurations are the same or overlap with each other.

[0143] The one or more Uu IDs associated with the first and second set of configurations may be intended for the services or logical channels of the first UE 204-1 mapped to the relay path. The one or more Uu IDs may be shared between the first UE 204-1 and the second UE 204-2 for transmissions and receptions on the relay path in the PDSCH and the PUSCH, respectively.

[0144] In some examples, the at least one of the one or more Uu IDs may comprise a cell Radio Network Temporary Identifier, C-RNTL The C-RNTI may be used as one of the Uu IDs, when the first UE 204-1 and the second UE 204-2 are enabled to identify a destination of the at least one TB when the at least one TB is to be transmitted towards or received from the network node 202.

[0145] In some examples, the at least one of the one or more Uu IDs may comprise a Configured Scheduling - RNTI, CS-RNTL The CS-RNTI may be used as one of the Uu IDs, when the first UE 204-1 and the second UE 204-2 are performing transmissions towards or receptions from the network node 202 on the Uu link / interface using semi-statically allocated resources by the network node 202.

[0146] In some examples, the at least one of the one or more Uu IDs may comprise a resume ID or an Inactive RNTI, l-RNTI for the HARQ processes on the relay path. The resume ID or the l-RNTI may be used as one of the Uu IDs, when the first UE 204-1 and / or the second UE 204-2 switch from a Radio Resource Control, RRC, inactive state to a RRC connected state. The resume ID or the I- RNTI may be used to determine a UE context associated with the first UE 204-1 and / or the second UE 204-2.

[0147] In some examples, the at least one of the one or more Uu IDs may comprise an UE ID of the first UE 204-1. The UE ID of the first UE 204-1 may be used as one of the Uu IDs, when a radio channel quality of the direct path between the first UE 204-1 and the network node 202 is greater than a radio channel quality of the Uu interface / second link 308 between the second UE and the network node 202.

[0148] In some examples, the at least one of the one or more Uu IDs may comprise an UE ID of the second UE 204-2. The UE ID of the second UE 204-2 may be used as one of the Uu IDs, when a radio channel quality of the Uu interface 308 between the second UE 204-2 and the network node 202 is greater than the radio channel quality of the direct path between the first UE 204-1 and the network node 202. The UE IDs of the first UE 204-1 and the second UE 204-2 have been assigned by at least one of: the network node 202, the first UE 204-1, and the second UE 204-2. In some examples, the network node 202 may determine the fixed size for the at least one TB, which is to be transmitted between the first UE 204-1 and the network node 202 via the second UE 204-2 on the relay path. The network node 202 may determine the fixed size for the at least one TB in accordance with evaluation of one or more measurements related to a UL radio channel of the second UE 204-2 on the relay path. Examples of the one or more measurements may include, but are not limited to, a UL radio channel quality and a UL congestion level of the second link 308 of the second UE 204-2.

[0149] Consider an example scenario, wherein the UL radio channel quality of the second link 308 of the second UE 204-2 may be measured in terms of parameters such as Reference Signal Received Power, RSRP, Reference Signal Received Quality, RSRQ, Received Signal Strength Indicator, RSSI, Signal-to-lnterference-plus-Noise Ratio, SINR, Signal to Interference Ratio, SIR, or the like. In such a scenario, if a parameter value is high, the network node may considerthat the UL radio channel quality is high (i.e., the UL radio channel quality is better). If the parameter value is low, the network node may consider that the UL radio channel quality is low (i.e., the UL radio channel quality is worse). Consider another example scenario, wherein the UL radio channel quality of the second link 308 of the second UE 204-2 may be measured in terms of parameters such as Block Error Ratio, BLER, interference level, or the like. In such a scenario, if a parameter value is high, the network node may consider that the UL radio channel quality is low. If the parameter value is high, the network node may consider that the UL radio channel quality is high.

[0150] In both of the above described scenarios, when the UL radio channel quality is high, the network node may assign a large size as the fixed size for the at least one TB. When the UL radio channel quality is low, the network node may assign a small size as the fixed size for the at least one TB.

[0151] Consider an example scenario, wherein the UL congestion level of the second link 308 of the second UE 204-2 is measured in terms of available Uu resources. In such a scenario, if a number of available resources is high, the network node may consider that the UL congestion level is low. If the number of available resources is low, the network node may consider that the UL congestion level is high. Consider another example scenario, wherein the UL congestion level of the second link 308 of the second UE 204-2 is measured in terms of parameters such as channel occupancy, interference level, or the like. In such a scenario, if a parameter value is high, the network node may consider that the UL congestion level is high. If the parameter value is low, the network node may consider that the UL congestion level is low.

[0152] In both of the above described scenarios, when the UL congestion level is high, the network node may assign a large size as the fixed size for the at least one TB. When the UL congestion level is low, the network node may assign a small size as the fixed size for the at least one TB.

[0153] Thus, the size configured for the at least one TB to be transmitted to the network node 202 via the relay path may depend on the second link 308 of the second UE 204-2.

[0154] The first UE 204-1 receives the aggregation configuration information from the network node 202. Based on the aggregation configuration information, the first UE 204-1 configures aggregation of transmissions between the first UE 204-1 and the second UE 204-2 in the protocol layer below the PDCP layer of the first UE 204-1 (i.e., in the MAC layer of the first link 306) and performs a first set of functions at the first link 306. Thereby, the first UE 204-1 may communicate with the network node 202 via the relay path, while configuring the lower layer aggregation.

[0155] In some examples, the first UE 204-1 may use at least a part of the aggregation configuration information for configuring the lower layer aggregation and the first set of functions. In some examples, the at least a part of the aggregation configuration information used by the first UE 204-1 may comprise at least one of: the configurations of the UP and the CP for the first link 306, the first set of configurations, and the one or more Uu IDs, and the fixed size configured for the at least one TB.

[0156] The first set of functions performed by the first UE 204-1 is described in detail in conjunction with Figs. 4A-4B, and 7.

[0157] Similar to the first UE 204-1, the second UE 204-2 receives the aggregation configuration information from the network node 202 or the first UE 204-1. Based on the aggregation configuration information, the second UE 204-2 configures aggregation of transmissions between the first UE 204-1 and the second UE 204-2 in the protocol layer below the PDCP layer of the first UE 204-1 (i.e., in the MAC layer of the first link 306) and performs a second set of functions at the first link 306 and the second link 308.

[0158] In some examples, the second UE 204-2 may use at least a part of the aggregation configuration information for configuring the lower layer aggregation on the relay path and the second set of functions. In some examples, the at least a part of the aggregation configuration information used by the second UE 204-2 may comprise at least one of: the configurations of the UP and the CP provided for each of the first link 306 and the second link 308, the second set of configurations, the one or more Uu IDs, the UL resources configured for transmission of the at least one TB, and the fixed size configured for the at least one TB.

[0159] The second set of functions performed by the second UE 204-2 is described in detail in conjunction with Figs. 4A and 4B.

[0160] The network node 202 may further determine whether to release the enabled lower layer aggregation. When it has been determined to release the enabled aggregation, the network node 202 may transmit an indication to the first UE 204-1 over the direct path and / or the second UE 204-2 over the second link 308. The indication causes the first UE 204-1 and / or the second UE 204-2 to release the aggregation configuration information.

[0161] In some examples, the network node 202 may determine itself to release the enabled aggregation.

[0162] In some examples, the network node 202 may receive a third report from the first UE 204-1. The third report may comprise at least one of: the assistance information, the measurement results, and a request for releasing the enabled lower layer aggregation. The assistance information may identify at least one of: QoS requirements associated with the services, traffic pattern characteristics and a buffer status of the first UE 204-1. Each measurement result in the third report may indicate a radio channel quality of the first link 306 between the first UE 204-1 and the second UE 204-2.

[0163] In accordance with evaluation of the third report, the network node 202 may determine to release the enabled lower layer aggregation for the first UE 204-1 or to release one of the at least one second UE for the first UE 204-1. Consider an example scenario, in accordance with evaluation of the third report, the network node 202 determines that the services of the first UE 204-1 are associated with non-delay and critical QoS requirements. In such a scenario, the network node 202 determines to release the enabled lower layer aggregation for the first UE 204-1. Consider another example scenario, in accordance with evaluation of the third report, the network node 202 determines that the radio channel quality of the first link 306 between the first UE 204-1 and the second UE 204-2 is low (for example, radio channel quality is worse). In such a scenario, the network node 202 determines to release the enabled lower layer aggregation for the first UE 204-1.

[0164] Optionally, the network node 202 may receive a fourth report from the second UE 204-2. The fourth report comprises at least one of: capability information, the measurement results related to the second UE, and a request for releasing the enabled aggregation. The capability information herein indicates whether or not the second UE 204-2 continues to operable as the relay UE for the first UE 204-1. The measurement results may indicate a radio channel quality of each of the first link 306 between the first UE 204-1 and the second UE 204-2 and the second link 308 between the second UE 204-2 and the network node 202. In accordance with evaluation of the fourth report, the network node 202 may determine to release the second UE 204-2 for the first UE 204-1 on the relay path.

[0165] Figs. 4A and 4B discloses a User Plane, UP, protocol stack, and a Control Protocol, CP, protocol stack for relay communication in a wireless communication network. In the wireless communication network, a network node 202 provides aggregation configuration for each of a first User Equipment, UE 204-1 and a second UE 204-2, when the network node 202 / first UE 204- 1 decides to communicate with the first UE 204-1 / network node 202 via a relay path. The second UE 204-2 is arranged between the first UE 204-1 and the network node 202 via a first link / i nter- UE interface 306 and a second link / Uu interface 308.

[0166] At least a part of the aggregation configuration information is used at each of the first UE 204-1 and the second UE 204-2 in configuring aggregation of transmissions between the first UE 204-1 and the second UE 204-2 in a protocol layer below a Packet Data Convergence Protocol, PDCP, layer of the first UE 204-1 (i.e., lower layer aggregation). The protocol layer below the PDCP layer may be a Medium Access Control, MAC, layer.

[0167] The aggregation configuration information may comprise configurations of UP and CP protocol stacks 402 and 404 for each of the first link 306 and the second link 308. The UP protocol stack 402 related to a Packet Data Unit, PDU, session, including the second UE 204-2 operating the aggregation of transmissions between the first UE 204-1 and the second UE 204-2 in the MAC layer of the first link 306 is disclosed in Fig. 4A. Similarly, the CP protocol stack 404 for control plane transport including the second UE 204-2 is disclosed in Fig. 4B. As disclosed in Figs. 4A and 4B, for the aggregation of transmissions between the first UE 204-1 and the second UE 204-2 in the MAC layer, the first UE 204-1 and the second UE 204-2 maintain respective MAC and Physical, PHY, entities at the first link 306. The MAC and PHY entities may correspond to MAC and PHY layers. The second UE 204-2 further maintains MAC and PHY entities at the second link 308 corresponding to the MAC and PHY layers. Thus, the configurations of the lower layers (MAC and PHY) are sufficient for the second UE 204-2.

[0168] The aggregation configuration information may further comprise configurations for upper protocol layers, and a MAC layer of the first UE 204-1. As disclosed in Fig. 4A, the upper protocol layers may comprise a Packet Data Unit, PDU, layer, a Uu Service Data Adaptation Protocol, SDAP, layer, a Uu PDCP layer, and a Uu RLC layer. The first UE 204-1 may maintain separate PDCP entities for different services or logical channels. The aggregation configuration information may further comprise configurations for radio bearers or the services of the first UE 204-1.

[0169] The aggregation configuration information may further comprise configurations for a MAC layer at the first link 306, a Physical layer, PHY, layer at the first link 306, a Uu MAC layer at the second link 308, and a Uu PHY layer at the second link 308. The aggregation configuration may further comprise a configuration to perform Hybrid Automatic Repeat Request, HARQ, processes / operations, by the second UE 204-2 on the relay path.

[0170] The aggregation configuration information may further comprise one or more access link, Uu, identifiers, IDs to be shared between the first UE 204-1 and the second UE 204-2 for transmissions and receptions on the relay path. The aggregation configuration information may further comprise Uplink, UL, resources configured for transmission of at least one Transport Block, TB, from the first UE 204-1 to the network node 202 via the second UE 204-2 on the relay path, and a fixed size for the at least one TB.

[0171] Based on at least the part of the aggregation configuration information, the first UE 204-1 configures the lower layer aggregation and performs a first set of functions at the first link 306. The first set of functions performed by the first UE 204-1 at the first link 306 may comprise building the at least one TB for the network node 202 and forwarding the at least one TB to the second UE 204-2 over the first link 306. The first UE 204-1 may build the at least one TB based on at least one of: the Uu IDs and the fixed size of the at least one TB. The at least one TB may correspond to the MAC PDUs of the first link 306, which comprises the aggregated transmissions between the first UE 204-1 and the second UE 204-2 on the relay path. Building and forwarding of the at least one TB is described detail in conjunction with Fig. 7.

[0172] Consider an example scenario, wherein the lower layer aggregation is configured at the first UE 204-1. In such a scenario, data received from the upper protocol layer, for example, the PDCP, of the first UE 204-1 may be aggregated at the MAC layer. The aggregated data herein may be MAC PDUs. The first UE 204-1 may build a TB for the aggregated MAC PDUs and transmit the TB from the MAC layer of the first UE 204-1 to the MAC layer of the second UE 204-2 on the first link 306, wherein the TB is further transmitted to the network node 202 via the second link 308 of the second UE 204-2.

[0173] It should be understood that the lower layer aggregation may also comprise transmission of TBs over both a Uu link / interface (i.e., direct path) of the first UE 204-1 and the first link 306 between the first UE 204-1 and the second UE 204-2 at the same time. For example, a TB1 may transmitted to the network node 202 via the Uu link of the first UE 204-1 and a TB2 may be transmitted to the network node 202 via the first link 306 and the second link 308. In some examples, the TBs may be transmitted only via the Uu link of the first UE 204-1. Similarly, based on at least the part of the aggregation configuration information, the second UE 204-2 configures the lower layer aggregation and performs a second set of functions at both the first link 306 and the second link 308, in order to relay the at least one TB (data packets) from the first UE 204-1 to the network node 202.

[0174] In some examples, the second set of functions performed by the second UE 204-2 may comprise functions related to MAC and PHY layers (L2 and LI layers, respectively).

[0175] A function related to the L2 may comprise performing HARQ processes / operations on the relay path by managing at least a part of functions of the HARQ processes in a Uu MAC layer and a Uu PHY layer on the second link 308 between the second UE and the network node. The HARQ process may involve transmitting data, receiving Acknowledgment, ACK, or Negative ACK, NACK, and performing retransmissions, if necessary. In particular, the HARQ process may rely upon receiving ACK for the packets. For example, if a sender sends a packet and then waits for the ACK to send another packet, it may be referred as a Stop and Wait, SAW process. Due to which, a round trip time may be increased because of increase in sender and receiver processing time and propagation delays. Hence, multiple SAW processes may be used in the wireless communication network. That is when one SAW is waiting for the ACK, another SAW process can send the data. Such SAW processes may be referred herein as the HARQ processes. The second UE 204-2 may maintain one or more HARQ entities. Each HARQ entity may maintain a number of HARQ processes for data transmissions and meanwhile, another number of HARQ processes for data receptions.

[0176] The functions related to the LI may comprise at least one of: relaying of the at least one TB from the first UE 204-1 to the network node 202. Due to the configured aggregation configuration information, the second UE 204-2 may receive the at least one TB comprising the aggregated MAC PDUs from the first UE 204-1 at the MAC layer and transmit the at least one TB to the network node 202 through the Uu PHY layer.

[0177] The functions related to the LI may further comprise receiving of data from the network node 202 for the first UE 204-1, performing channel processing of a PDSCH and a PUSCH, signaling a HARQ feedback to the network node. In some examples, the second UE 204-2 may maintain the functions related to LI and L2 layers depending on a transmission medium associated with the first link 306 between the first UE 204- 1 and the second UE 204-2.

[0178] Thereby, by limiting the second UE 204-2 with a minimum set of functions related to the LI and L2 layers, the lower layer aggregation may be achieved with lower overhead in both control signaling and with lower latency of transmission and reception of data.

[0179] In some examples, the second set of functions may comprise additional functions, which may be supported as additional capabilities for the second UE 204-2 on the first link 306 and the second link 308. The additional functions may relate to other functions and processing capabilities in the LI and L2 layers. Examples of the additional functions may include, but are not limited to, providing data transfer and radio allocation services to the upper protocol layers in the second link 308, mapping between logical and transport channels for the transmissions and the receptions on the relay path (both uplink and downlink), multiplexing of MAC Service Data Units, SDUs onto the at least one TB (in uplink), de-multiplexing of the MAC SDUs from the at least one TB (in downlink), reporting a schedule of the transmissions on the relay path 208 to the network node 202 (in uplink), performing error correction of the transmissions through the HARQ processes (in uplink and downlink), and prioritizing the logical channels on the relay path (in uplink).

[0180] Optionally, an adaptation layer may be implemented at the first link 306 between the first UE and the second UE 204-2. For example, the adaptation layer may be arranged above the MAC layer of the transmission medium of the first link 306 and below the Uu MAC layer. Alternatively, the adaptation layer may be implemented at the second link 308 between the second UE 204-2 and the network node 202.

[0181] In case if the adaptation layer is implemented, the network node 202 may provide a configuration for the adaptation layer in the aggregation configuration information. The configuration may be provided for any of the above described implementations of the adaptation layer.

[0182] In particular, the configuration provided for the adaptation layer implemented at the first link 306 on the relay path may cause the adaptation layer to adapt a difference between the second and first set of functions performed by the second and first UEs 204-2 and 204-1 to achieve transmissions and receptions over the first link 306 and the second link 308. The configuration further causes the adaptation layer to manage a difference of functions between different vendors providing the first UE 204-1 and the second UE 204-2.

[0183] Fig. 5A is a sequence diagram illustrating example signaling for relay path communication in a wireless communication network. In the wireless communication network, a first User Equipment, UE 204-1 first accesses to a network node 202 via a direct path. Thereafter, the network node 202 configures a relay UE for the first UE 204-1 to enable aggregation of transmissions between the first UE 204-1 and the relay UE in a protocol layer below a Packet Data Convergence Protocol, PDCP, layer of the first UE 204-1 (referred to as lower layer aggregation).

[0184] In some examples, the network node 202 may decide itself to enable the lower layer aggregation for the first UE 204-1.

[0185] In some examples, the first UE 204-1 establishes 500 interaction with second UEs 204-2 - 204-N through a first link 306. The first link 306 may be an inter-UE connection between the first UE 204-1 and a second UE (204-2 - 204-N). Upon the interaction, the first UE 204-1 sends 501 a first report to the network node 202. The first report may comprise assistance information, measurement results, and a request for the lower layer aggregation. The assistance information may identify at least one of: Quality of Service, QoS, requirements associated with services of the first UE 204-1 and traffic patter characteristics and buffer status of the first UE 204-1. Each measurement result may indicate a radio channel quality of the first link between the first UE 204-1 and one of the at least one second UE (204-2 - 204-N).

[0186] In accordance with evaluation of the first report, the network node 202 decides 502 to enable the lower layer aggregation for the first UE 204-1.

[0187] From the first report, the network node 202 determines 503 that each of the second UEs 204-2 - 204-N may be capable of operating as a relay UE for the first UE 204-1. The network node 202 instructs the second UEs 204-2 - 204-N to transmit a second report. Based upon instructions from the network node 202, the second UEs 204-2 - 204-N transmit 504 the second report to the network node 202. For example, the second report from the second UE 204-2 may comprise capability information and measurement results of the second UE 204-2. The capability information may indicate whether or not the second UE 204-2 is operable as the relay UE. The measurement results may indicate a radio channel quality of each of the first link between the first UE and the second UE 204-2 and a second link between the second UE 204-2 and the network node 202.

[0188] In accordance with evaluation of the second report, the network node 202 selects 505 the second UE 204-2 from the second UEs 204-2 - 204-N as the relay UE for the first UE 204-1. The network node 202 configures 510 the selected second UE 204-2 for the first UE 204-1 on the relay path. By configuring, the second UE 204-2 may act as a relay UE between the first UE 204-1 and the network node 202 via the first link / inter-UE interface and the second link / Uu interface, respectively.

[0189] Upon configuring the relay UE for the first UE 204-1, the network node 202 transmits 515 a Radio Resource Control, RRC, reconfiguration message to each of the first UE 204-1 and the second UE 204-2. The RRC reconfiguration message comprises aggregation configuration information.

[0190] In some examples, the aggregation configuration information transmitted to the second UE 204- 2 in the RRC reconfiguration message may comprise at least one of:

[0191] - configurations of User Plane, UP, and Control Plane, CP, protocol stacks for the first link;

[0192] - configurations of UP and CP protocol stacks for the second link;

[0193] - a physical layer configuration for a physical, PHY, layer in each of the first link and the second link;

[0194] - a configuration to perform Hybrid Automatic Repeat Request, HARQ, processes on the relay path;

[0195] - a MAC layer configuration for the MAC layer in each of the first link and the second link;

[0196] - one or more access link, Uu , Identifiers, IDs, Uu IDs to be shared between the first UE 204-1 and the second UE 204-2; - Uplink, UL, resources configured for transmission of at least one Transport Block, TB, from the first UE 204-1 to the network node 202 via the second UE 204-2 on the relay path; and

[0197] - a fixed size for the at least one TB.

[0198] In some examples, the aggregation configuration information transmitted to the first UE 204-1 in the RRC configuration may comprise at least one of the following:

[0199] - configurations of UP and CP protocol stacks for the first link;

[0200] - a radio bearer configuration for Radio Bearers, RBs, or services of the first UE mapped to the relay path;

[0201] - a configuration of each of upper protocol layers for the first UE, said upper protocol layers comprising a Service Data Adaptation Protocol, SDAP, a PDCP, and a Radio Link Control, RLC; and

[0202] - a MAC layer configuration for the MAC layer in the first link; one or more access link, Uu , Identifiers, IDs, Uu IDs to be shared between the first UE 204-1 and the second UE 204-2;

[0203] - UL resources configured for transmission of at least one TB from the first UE 204-1 to the network node 202 via the second UE 204-2 on the relay path; and

[0204] - a fixed size for the at least one TB.

[0205] Upon receiving the aggregation configuration information in the RRC reconfiguration message, the first UE 204-1 and the second UE 204-2 transmit 520 a RRC reconfiguration complete message to the network node 202.

[0206] In some examples, the RRC reconfiguration message (transmitted from the network node 202 at step 515) may only configure the first UE 204-1 and the second UE 204-2 with the aggregation configuration information. Each of the first UE 204-1 and the second UE 204-2 may use a dedicated signaling to activate / configure the lower layer aggregation using at least a part of the aggregation configuration information. Examples of the dedicated signaling may include, but are not limited to, a MAC Control Element, CE, a Downlink Control Information, DCI, command, or the like.

[0207] In some examples, suitable procedures may trigger the second UE 204-2 present in an RRC idle / inactive state to initiate a RRC connection setup / resume procedure with the network node 202. The suitable procedures may be triggered by a message. Since the first UE 204-1 communicates with the second UE 204-2 through the first link / ideal backhaul, the message herein may be a RRC message forwarded by the network node 202 to the second UE 204-2, upon reception of the message from the first UE 204-1.

[0208] Fig. 5B is a sequence diagram illustrating example signaling for releasing aggregation of transmissions between a first User Equipment, UE 204-1 and the second UE 204-2 in a protocol layer below a Packet Data Convergence Protocol, PDCP, layer of the first UE 204-1 (referred to as lower layer aggregation herein).

[0209] In some examples, the first UE 204-1 may transmit 523 a third report to a network node 202 for releasing the enabled lower layer aggregation on the relay path. The third report may comprise at least one of: assistance information and measurement results related to the first UE 204-1, and a request for releasing the enabled aggregation. The assistance information may identify at least one of: Quality of Service, QoS, requirements associated with services of the first UE 204-1 and traffic pattern characteristics and buffer status of the first UE 204-1. The measurement results in the third report may indicate a radio channel quality of the first link between the first UE 204-1 and the second UE 204-2.

[0210] Optionally, the second UE 204-2 may also transmit 524 a fourth report to a network node 202 for releasing the enabled lower layer aggregation on the relay path. The fourth report comprises at least one of: capability information, the measurement results related to the second UE, and a request for releasing the enabled aggregation. The capability information herein indicates whether or not the second UE 204-2 continues to operable as the relay UE for the first UE 204-1. The measurement results may indicate a radio channel quality of each of the first link between the first UE 204-1 and the second UE 204-2 and the second link between said second UE 204-2 and the network node 202.

[0211] The network node 202 decides 525 to release the enabled lower layer aggregation in accordance with the third report and / or the fourth report. In some examples, the network node 202 may decide itself to release the enabled lower layer aggregation.

[0212] Upon deciding to release the enabled lower layer aggregation, the network node 202 transmits 530 a Radio Resource Control, RRC, reconfiguration message to each of the first UE 204-1 and the second UE 204-2 to release the aggregation configuration information used for the lower layer aggregation.

[0213] Thereafter, the first UE 204-1 and the second UE 204-2 transmit 535 a RRC reconfiguration complete message to the network node 202. The RRC reconfiguration complete message may indicate release of the aggregation configuration information used for the lower layer aggregation.

[0214] FIGs. 6A, 6B, and 6C disclose example illustration of transmitting aggregation configuration information by a network node 202 to first and second UEs 204-1 and 204-2.

[0215] In some examples, as disclosed in Fig. 6A, the network node 202 directly transmits (at step 2.1) the aggregation configuration information to the first UE 204-1 over a direct path 206 (i.e., using an access link, Uu, interface). Also, the network node 202 directly transmits (at step 2.2) the aggregation configuration information to the second UE 204-2 using an Uu interface / second link 308.

[0216] In some examples, as disclosed in Fig. 6B, the network node 202 (at step 2.1) transmits the aggregation configuration information to the first UE 204-1 over the direct path 206. Further, the first UE 204-1 (at step 2.3) transmits the aggregation information to the second UE 204-2 over the first link / inter-UE interface 306.

[0217] In some examples, as disclosed in Fig. 6C, the network node 202 (at step 2.2) transmits the aggregation configuration information to the second UE 204-2 over the second link / Uu interface 308. Further, the second UE 204-2 (at step 2.4) transmits the aggregation information to the first UE 204-1 over the first link / inter-UE interface 306.

[0218] Based on at least a part of the aggregation configuration information, the first UE 204-1 configures aggregation of transmissions between the first UE 204-1 and the second UE 204-2 in a protocol layer below a Packet Data Convergence Protocol, PDCP, layer of the first UE 204-1 and performs a first set of functions.

[0219] Similarly, based on at least a part of the aggregation configuration information, the second UE 204-2 configures aggregation of transmissions between the first UE 204-1 and the second UE 204-2 in a protocol layer below the PDCP layer of the first UE 204-1 and performs a second set of functions. The aggregation configuration information, and the first and second set of functions are described in detail in conjunction with above figures, therefore repeated description is omitted herein.

[0220] Fig. 7 discloses an example illustration of handling relay communication in a wireless communication network. In the wireless communication network disclosed herein, a network node 202 configures, for a first User Equipment, UE 204-1, a second UE 204-2 as a relay UE on a relay path. Thereby, the first UE 204-1 is allowed to communicate with the network node 202 via the second UE 204-2 on the relay path.

[0221] The network node 202 further transmits aggregation configuration information for each of the first UE 204-1 and the second UE 204-2. The aggregation configuration information may comprise at least one of: configurations of User Plane, UP, and Control Plane, CP, protocol stacks for the first link 306, configurations of UP and CP protocol stacks for the second link 308, a first set of configurations for the first UE 204-1, a second set of configurations for the second UE 204-2, one or more access link, Uu, identifiers, IDs associated with the first set of configurations and the second set of configurations, Uplink, UL, resources configured for transmission of at least one Transport Block, TB, from the first UE 204-1 to the network node 202 via the second UE 204-2 on the relay path, and a fixed size for the at least one TB.

[0222] Based on at least a part of the aggregation configuration, each of the first and second UEs 204-1 and 204-2 performs various functions as disclosed in Fig. 7.

[0223] In particular, when the first UE 204-1 identifies (step 1) arrival of new data for a service mapped to the relay path, the first UE 204-1 builds (step 2) a TB. The TB referred herein corresponds to a Medium Access Control, MAC, Packet Data Unit, PDU, which may comprises data packets associated with the aggregated transmissions between the first UE 204-1 and the second UE 204- 2 at the MAC layer.

[0224] The first UE 204-1 may build the TB based on at least one of: the one or more Uu IDs, the UL resources, and the fixed TB size transmitted in the aggregation configuration information. In some examples, the first UE 204-1 may build the TB with the one or more Uu IDs and according to a transport format size provided by the UL resources. Alternatively, the first UE 204-1 may build the TB with the one or more Uu IDs and according to the fixed size indicated in the aggregation configuration information for the TB. The fixed size for the TB may be predefined or configured by the network node 202. Configuring the fixed size for the TB by the network node is described in detail in conjunction with Fig. 3, therefore, repeated description is omitted herein.

[0225] After building the TB, the first UE 204-1) forwards (step 3) the TB to the second UE 204-2 via the first link / inter-UE interface 306.

[0226] The second UE 204-2 transmits (step 4) the TB received from the first UE 204-1 to the network node 202. In some examples, the second UE 204-2 may map the TB to one of HARQ entities to operate transmissions and retransmissions of the at least one TB over the second link 308. Each HARQ entity may control one or more HARQ processes to be performed by the second UE 204- 2.

[0227] The second UE 204-2 may transmit the TB to the network node 202 based on at least one of: the one or more Uu IDs, the UL resources, and the fixed TB size transmitted in the aggregation configuration information.

[0228] In some examples, if the UL resources indicate a larger size for the TB than the fixed size, the second UE 204-2 may append padding bits to the TB received from the first UE 204-1. Thereby, the second UE 204-2 transmits the TB including the padding bits to the network node 202.

[0229] In some examples, if the UL resource indicate a smaller size for the TB than the fixed size, the second UE 204-2 may divide the TB received from the first UE 204-1 into a plurality of segments. The second UE 204-2 may transmit the plurality of segments to the network node 202 in a plurality of transmissions.

[0230] The second UE 204-2 transmits the TB to the network node 202 using the UL resources allocated for transmission of the TB.

[0231] Fig. 8 is a flowchart illustrating example method steps of a method 800 performed by a network node for communicating with a first User Equipment, UE, via a relay path. At step 810, the method 800 comprises configuring a second UE as a relay UE for the first UE on the relay path. The second UE is arranged between the first UE and the network node via a first link and a second link, respectively. In some examples, the first link may be an inter-UE interface and the second link may be an access link, Uu interface. The proposed inter-UE interface may be an ideal backhaul link with low latency and high throughput. Such an inter-UE interface / first link may achieve faster delivery of transmissions between the first UE and the second UE.

[0232] In some embodiments, the step 810 of configuring the second UE as the relay UE for the first UE is preceded by a step of selecting the second UE as the relay UE for the first UE. For selecting the second UE, the method may comprise receiving a first report related to the first UE. In some examples, the first UE may transmit the first report to the network node, upon establishing and maintaining a connection with at least one second UE via the first link. The first report may comprise at least one of: assistance information, measurement results, and a request for aggregating transmissions between the first UE and the relay UE on the relay path. In some examples, the assistance information may indicate at least one of: Quality of Service, QoS, requirements associated with the services of the first UE and traffic pattern characteristics and buffer status of the first UE. In some examples, each measurement result in the first report may indicate a radio channel quality of a first link between the first UE and one of at least one second UE. In some examples, the network node may receive the first report from the first UE or from one of the at least one second UE.

[0233] In accordance with the first report, the method may comprise determining whether to enable the requested aggregation for the first UE on the relay path. When it has been determined to enable the requested aggregation for the first UE on the relay path, the method may comprise determining, from the first report, the at least one second UE being operable as the relay UE for the first UE. The method may further comprise receiving a second report from each of the determined at least one second UE. The second report received from a second UE of the at least one second UE may comprise capability information and measurement results related to that second UE. The capability information of the second UE may indicate whether the second UE is operable as the relay UE when it is determined to enable the requested aggregation for the first UE. The measurement results related to the second UE of the at least one second UE may indicate a radio channel quality of each of the first link between the first UE and the second UE and the second link between the second UE and the network node. In accordance with evaluation of the second report, the method may comprise selecting the second UE from the at least one second UE as the relay UE for the first UE.

[0234] Upon configuring the second UE for the first UE as the relay UE, at step 815, the method 800 comprises transmitting aggregation configuration information for each of the first UE and the second UE. At least a part of the aggregation configuration information is intended for use at each of the first UE and the second UE in configuring aggregation of transmissions between the first UE and the second UE in a protocol layer below a Packet Data Convergence Protocol, PDCP, layer of the first UE.

[0235] In some embodiments, the protocol layer below the PDCP layer of the first UE is a Medium Access Control, MAC, layer.

[0236] In some embodiments, the aggregation configuration information comprises at least one of: configurations of User Plane, UP, and Control Plane, CP, protocol stacks for the first link, configurations of UP and CP protocol stacks for the second link, a first set of configurations for the first UE, a second set of configuration for the second UE, one or more access link, Uu, identifiers, IDs associated with the first set of configurations and the second set of configurations, Uplink, UL, resources configured for transmission of at least one Transport Block, TB, from the first UE to the network node via the second UE on the relay path, and a fixed size for the at least one TB. The at least one TB corresponds to MAC Protocol Data Units, PDUs, of the first link.

[0237] In some embodiments, the first set of configurations for the first UE comprises at least one of: a radio bearer configuration for Radio Bearers, RBs, or services of the first UE mapped to the relay path, a configuration of each of upper protocol layers for the first UE, wherein the upper protocol layers comprising a Service Data Adaptation Protocol, SDAP, a PDCP, and a Radio Link Control, RLC, and a MAC layer configuration for the MAC layer in the first link.

[0238] In some embodiments, the second set of configurations for the second UE comprises at least one of: a physical layer configuration for a physical, PHY, layer in each of the first link and the second link, wherein the physical layer configuration is for channel processing of a Physical Data Shared Channel, PDCSH and a Physical Uplink Shared Channel, PUSCH on the relay path, a configuration to perform Hybrid Automatic Repeat Request, HARQ, processes on the relay path, and a MAC layer configuration for the MAC layer in each of the first link and the second link.

[0239] In some embodiments, the MAC layer configurations in the first set of configurations and the second set of configurations are the same or overlap with each other.

[0240] In some embodiments, the one or more Uu IDs associated with the first set and the second set of configurations are intended for services or logical channels of the first UE mapped to the relay path. The one or more Uu IDs being shared between the first UE and the second UE for transmissions and receptions on the relay path.

[0241] In some examples, at least one of the one or more Uu IDs associated with the first set and the second set of configurations comprises one or more of:

[0242] - a Cell Radio Network Temporary Identifier, C-RNTI, when the first UE and the second UE are enabled to identify a destination of the at least one TB when the at least one TB is to be transmitted towards or received from the network node;

[0243] - a Configured Scheduling - RNTI, CS-RNTI, when the first UE and the second UE are performing transmissions towards or receptions from the network node on a Uu link using a semi-statically allocated resources by the network node;

[0244] - a resume ID or an Inactive RNTI, l-RNTI for the HARQ processes on the relay path, when the first UE and / or the second UE switch from an Radio Resource Control, RRC, inactive state to a RRC connected state, said resume ID or l-RNTI being used to determine a UE context associated with the first UE and / or the second UE;

[0245] - an UE ID of the first UE, when a radio channel quality of the direct path between the first UE and the network node is greater than a radio channel quality of the second link between the second UE and the network node; and

[0246] - an UE ID of the second UE, when the radio channel quality of the second link between the second UE and the network node is greater than the radio channel quality of the direct path between the first UE and the network node, wherein the UE IDs of the first UE and the second UE have been assigned by at least one of: the network node, the first UE, and the second UE.

[0247] In some embodiments, the at least the part of the aggregation configuration information is intended to cause the first UE to perform a first set of functions at the first link. The first set of functions performed by the first UE is described in detail in conjunction with Figs. 3 and 9, therefore the repeated description is omitted herein.

[0248] In some embodiments, the at least the part of the aggregation configuration information is intended to cause the second UE to perform at least a second set of functions at the first link and the second link on the relay path. The second set of functions performed by the second UE is described in detail in conjunction with Figs. 3 and 10 therefore the repeated description is omitted herein.

[0249] In some embodiments, the aggregation configuration information further comprises a configuration for an adaptation layer to be implemented at the first link on the relay path. Said configuration causes the adaptation layer to perform one or more of: adapting a difference between the second and first set of functions performed by the second and first UEs to achieve the transmissions and the receptions over the first link and the second link, and managing a difference of functions between different vendors providing the first UE and the second UE. The aggregation configuration information further comprises a configuration for an adaptation layer to be implemented at the second link on the relay path.

[0250] In some embodiments, the step of transmitting the aggregation configuration information comprises transmitting, to the first UE over a direct path, the aggregation configuration information, wherein the aggregation configuration information is transmitted by the first UE to the second UE over the first link. In some embodiments, the step of transmitting the aggregation configuration information comprises transmitting directly, to the first UE and the second UE, the aggregation configuration information.

[0251] Fig. 9 is a flowchart illustrating example method steps of a method 900 performed by a first User Equipment, UE, for managing communication with a network node via a second UE on a relay path. The second UE is arranged between the first UE and the network node via a first link and a second link, respectively.

[0252] At step 915, the method 900 comprises receiving aggregation configuration information. In some examples, the first UE may receive the aggregation configuration information from the network node over a direct path.

[0253] In some embodiments, the aggregation configuration information comprises at least one of: configurations of User Plane, UP, and Control Plane, CP, protocol stacks for the first link, configurations of UP and CP protocol stacks for the second link, a first set of configurations for the first UE, a second set of configuration for the second UE, one or more access link, Uu, identifiers, IDs associated with the first set of configurations and the second set of configurations, Uplink, UL, resources configured for transmission of at least one Transport Block, TB, from the first UE to the network node via the second UE on the relay path, and a fixed size for the at least one TB. The at least one TB corresponds to MAC Protocol Data Units, PDUs, of the first link.

[0254] Based on at least a part of the aggregation configuration information, at step 920, the method 900 comprises configuring aggregation of transmissions between the first UE and the second UE in a protocol layer below a Packet Data Convergence Protocol, PDCP, layer of the first UE; and performing a first set of functions at the first link.

[0255] In some examples, the first set of functions may comprise building the at least one TB for the network node and forwarding the at least one TB to the second UE over the first link. Building of a TB at the first UE is described in detail in conjunction with Fig. 7.

[0256] Fig. 10 is a flowchart illustrating example method steps of a method 1000 performed by a second User Equipment, UE, for managing communication between a network node and a first UE on a relay path. The second UE is arranged between the first UE and the network node via a first link and a second link, respectively.

[0257] At step 1015, the method 1000 comprises receiving aggregation configuration information from one of the network node and the first UE. In some embodiments, the aggregation configuration information comprises at least one of: configurations of User Plane, UP, and Control Plane, CP, protocol stacks for the first link, configurations of UP and CP protocol stacks for the second link, a first set of configurations for the first UE, a second set of configuration for the second UE, one or more access link, Uu, identifiers, IDs associated with the first set of configurations and the second set of configurations, Uplink, UL, resources configured for transmission of at least one Transport Block, TB, from the first UE to the network node via the second UE on the relay path, and a fixed size for the at least one TB. The at least one TB corresponds to MAC Protocol Data Units, PDUs, of the first link.

[0258] Based on at least a part of the aggregation configuration information, at step 1020, the method 1000 comprises configuring aggregation of transmissions between the first UE and the second UE in a protocol layer below a Packet Data Convergence Protocol, PDCP, layer of the first UE; and performing a second set of functions at the first link and the second link.

[0259] In some examples, the first set of functions may comprise building the at least one TB for the network node and forwarding the at least one TB to the second UE over the first link. Building of a TB at the first UE is described in detail in conjunction with Fig. 7.

[0260] In some examples, the second set of functions may comprise at least one of the following:

[0261] - performing Hybrid Automatic Repeat Request, HARQ, processes on the relay path by managing at least a part of functions of the HARQ processes at the MAC layer and the PHY layer in the second link;

[0262] - transmitting the at least one TB received from the first UE to the network node over the second link, in accordance with at least one of: the UL resources configured for the transmission of the at least one TB and the fixed size determined for the at least one TB;

[0263] - mapping each of the at least one TB received from the first UE to one of HARQ entities to operate transmissions and retransmissions of the at least one TB over the second link;

[0264] - performing channel processing of the PDSCH and the PUSCH on the relay path; and

[0265] - signaling of a HARQ feedback to the network node over the second link.

[0266] In some examples, the second set of functions may further comprise at least one of the following: - providing at least one service to the upper protocol layers in the second link, said at least one service comprising data transferring to the upper protocol layers and radio resource allocation;

[0267] - mapping between logical and transport channels for the transmissions and the receptions on the relay path;

[0268] - multiplexing of MAC Service Data Units, SDUs onto the at least one TB;

[0269] - de-multiplexing of the MAC SDUs from the at least one TB;

[0270] - reporting a schedule of the transmissions on the relay path to the network node;

[0271] - performing error correction of the transmissions through the HARQ processes; and

[0272] - prioritizing the logical channels on the relay path.

[0273] Fig. 11 is an example schematic diagram showing an apparatus 202. The apparatus 202 may e.g. be comprised in a network node. The apparatus 202 is capable of communicating with a first User Equipment, UE, via a relay path and may be configured to cause performance of the method 800 for communicating with the first UE via the relay path.

[0274] According to at least some examples, the apparatus 202 in Fig. 11 comprises one or more modules. These modules may e.g. be a memory 1102, a processor 1104, a controlling circuitry 1106, a transceiver 1108, a determination module 1110, and an aggregation module 1112. The controlling circuitry 1106, may in some examples be adapted to control the above mentioned modules.

[0275] The memory 1102, the processor 1104, the transceiver 1108, the determination module 1110, and the aggregation module 1112, as well as the controlling circuitry 1106, may be operatively connected to each other.

[0276] The controlling circuitry 1106 may be adapted to control the steps as executed by the network node. For example, the controlling circuitry 1106 may be adapted to communicate with the first UE via the relay path (as described above in conjunction with the method 800 and Fig. 8).

[0277] The determination module 1110 may be adapted to determine whether to enable aggregation of transmissions between the first UE and a relay UE on the relay path. When it has been determined to enable the aggregation, the determination module 1110 may be adapted to select a second UE from at least one second UE as the relay UE for the first UE.

[0278] The aggregation module 1112 may be adapted to configure the second UE for the first UE as the relay UE and to generate aggregation configuration information for each of the first UE and the second UE.

[0279] The transceiver 1108 may be adapted to transmit the aggregation configuration information to the first UE and / or the second UE. At least a part of the aggregation configuration information is intended for use at each of the first UE and the second UE in configuring aggregation of transmissions between the first UE and the second UE in a protocol layer below a Packet Data Convergence Protocol, PDCP, layer of the first UE.

[0280] The determination module 1110 may be also be adapted to determine whether or not to release the enabled aggregation. When it has been determined to release the enabled aggregation, the transceiver 1108 may be adapted to transmit an indication to the first UE and / or the second UE to release the aggregation configuration information.

[0281] Further, the processor 1104 may be adapted to enable the transceiver 1108 to transmit / receive at least one Transport Block, TB, to the first UE through the second UE on the relay path.

[0282] Further, the memory 1102 is adapted to store at least one of, UE context associated with the first and second UEs, the aggregation configuration information, or the like.

[0283] Fig. 12 is an example schematic diagram showing an apparatus 204-1. The apparatus 204-1 may e.g. be comprised in a first User Equipment, UE. The apparatus 204-1 is capable of managing communication with a network node via a second UE on a relay path and may be configured to cause performance of the method 900 for managing the communication with the network node via the second UE on the relay path.

[0284] According to at least some examples, the apparatus 204-1 in Fig. 12 comprises one or more modules. These modules may e.g. be a memory 1202, a processor 1204, a controlling circuitry 1206, a transceiver 1208, a configuration module 1210, and a Transport Block, TB, construct module 1212. The controlling circuitry 1206, may in some examples be adapted to control the above mentioned modules.

[0285] The memory 1202, the processor 1204, the transceiver 1208, the configuration module 1210, and the TB construct module 1212, as well as the controlling circuitry 1206, may be operatively connected to each other.

[0286] The controlling circuitry 1206 may be adapted to control the steps as executed by the first UE. For example, the controlling circuitry 1206 may be adapted for managing the communication with the network node via the second UE on the relay path (as described above in conjunction with the method 900 and Fig. 9).

[0287] The transceiver 1208 may be adapted to receive aggregation configuration information from the network node.

[0288] The configuration module 1210 may be adapted to use least a part of the aggregation configuration information for configuring aggregation of transmissions between the first UE and the second UE in a protocol layer below a Packet Data Convergence Protocol, PDCP, layer of the first UE.

[0289] The TB construct module 1212 may be adapted to build at least one TB based on at least a part of the aggregation configuration information.

[0290] The transceiver 1208 may be adapted to forward the at least one TB to the network node via the second UE.

[0291] Further, the processor 1204 may be adapted to prepare a first report and a second report. The first report includes a request for the network node to enable the aggregation of the transmissions between the first UE and a relay UE on the relay path. The second report includes a request for the network node to release the enabled aggregation.

[0292] Further, the memory 1202 is adapted to store at least one of: the aggregation configuration information, the TB, the first report, the second report, or the like. Fig. 13 is an example schematic diagram showing an apparatus 204-2. The apparatus 204-2 may e.g. be comprised in a second User Equipment, UE. The apparatus 204-2 is capable of managing communication between a network node and a first UE on a relay path and may be configured to cause performance of the method 1000 for managing communication between the network node and the first UE on the relay path.

[0293] According to at least some examples, the apparatus 204-1 in Fig. 13 comprises one or more modules. These modules may e.g. be a memory 1302, a processor 1304, a controlling circuitry 1306, a transceiver 1308, a configuration module 1310, and a L1 / L2 function module 1314. The controlling circuitry 1306, may in some examples be adapted to control the above mentioned modules.

[0294] The memory 1302, the processor 1304, the transceiver 1308, the configuration module 1210, and the L1 / L2 function module 1314, as well as the controlling circuitry 1306, may be operatively connected to each other.

[0295] The controlling circuitry 1306 may be adapted to control the steps as executed by the second UE. For example, the controlling circuitry 1306 may be adapted for managing communication between the network node and the first UE on the relay path (as described above in conjunction with the method 1000 and Fig.10).

[0296] The transceiver 1308 may be adapted to receive aggregation configuration information from the network node or the first UE.

[0297] The configuration module 1310 may be adapted to use at least a part of the aggregation configuration information for configuring aggregation of transmissions between the first UE and the second UE in a protocol layer below a Packet Data Convergence Protocol, PDCP, layer of the first UE.

[0298] The L1 / L2 function module 1314 may be adapted to perform a second set of functions related to layers 1 and 2 (i.e., a physical layer and a Medium Access Control, MAC layer, respectively). In an example, one of the second set of functions may include transmitting a Transport Block, TB, received from the UE to the network node through the transceiver 1308. Further, the processor 1304 may be adapted to prepare a third report and a fourth report. The third report may indicate whether or not the second UE continues to operate as the relay UE for the first UE. The fourth report includes a request for the network node to release the enabled lower layer aggregation.

[0299] Further, the memory 1302 is adapted to store at least one of: the aggregation configuration information, the third report, the fourth report, or the like.

[0300] Fig. 14 is a block diagram of a telecommunication network connected via an intermediate network to a host computer according to some examples. With reference to Fig. 14, in accordance with an embodiment, a communication system includes telecommunication network 4410, such as a 3GPP-type cellular network, which comprises access network 4411, such as a radio access network, and core network 4414. Access network 4411 comprises a plurality of base stations 4412a, 4412b, 4412c, such as NBs, eNBs, gNBs or other types of wireless access points, each defining a corresponding coverage area 4413a, 4413b, 4413c. Each base station 4412a, 4412b, 4412c is connectable to core network 4414 over a wired or wireless connection 4415. A first UE 4491 located in coverage area 4413c is configured to wirelessly connect to, or be paged by, the corresponding base station 4412c. A second UE 4492 in coverage area 4413a is wirelessly connectable to the corresponding base station 4412a. While a plurality of UEs 4491, 4492 are illustrated in this example, the disclosed embodiments are equally applicable to a situation where a sole UE is in the coverage area or where a sole UE is connecting to the corresponding base station 4412.

[0301] Telecommunication network 4410 is itself connected to host computer 4430, which may be embodied in the hardware and / or software of a standalone server, a cloud-implemented server, a distributed server or as processing resources in a server farm. Host computer 4430 may be under the ownership or control of a service provider, or may be operated by the service provider or on behalf of the service provider. Connections 4421 and 4422 between telecommunication network 4410 and host computer 4430 may extend directly from core network 4414 to host computer 4430 or may go via an optional intermediate network 4420. Intermediate network 4420 may be one of, or a combination of more than one of, a public, private or hosted network; intermediate network 4420, if any, may be a backbone network or the Internet; in particular, intermediate network 4420 may comprise two or more sub-networks (not shown).

[0302] The communication system of Fig. 14 as a whole enables connectivity between the connected UEs 4491, 4492 and host computer 4430. The connectivity may be described as an over-the-top, OTT connection 4450. Host computer 4430 and the connected UEs 4491, 4492 are configured to communicate data and / or signaling via OTT connection 4450, using access network 4411, core network 4414, any intermediate network 4420 and possible further infrastructure (not shown) as intermediaries. OTT connection 4450 may be transparent in the sense that the participating communication devices through which OTT connection 4450 passes are unaware of routing of uplink and downlink communications. For example, base station 4412 may not or need not be informed about the past routing of an incoming downlink communication with data originating from host computer 4430 to be forwarded (e.g., handed over) to a connected UE 4491. Similarly, base station 4412 need not be aware of the future routing of an outgoing uplink communication originating from the UE 4491 towards the host computer 4430.

[0303] Fig. 15 is a block diagram of a host computer communicating via a base station with a user equipment over a partially wireless connection according to some examples. Example implementations, in accordance with an embodiment, of the UE, base station and host computer discussed in the preceding paragraphs will now be described with reference to Fig. 15. In communication system 4500, host computer 4510 comprises hardware 4515 including communication interface 4516 configured to set up and maintain a wired or wireless connection with an interface of a different communication device of communication system 4500. Host computer 4510 further comprises processing circuitry 4518, which may have storage and / or processing capabilities.

[0304] In particular, processing circuitry 4518 may comprise one or more programmable processors, application-specific integrated circuits, field programmable gate arrays or combinations of these (not shown) adapted to execute instructions. Host computer 4510 further comprises software 4511, which is stored in or accessible by host computer 4510 and executable by processing circuitry 4518. Software 4511 includes host application 4512. Host application 4512 may be operable to provide a service to a remote user, such as UE 4530 connecting via OTT connection 4550 terminating at UE 4530 and host computer 4510. In providing the service to the remote user, host application 4512 may provide user data which is transmitted using OTT connection 4550.

[0305] Communication system 4500 further includes base station 4520 provided in a telecommunication system and comprising hardware 4525 enabling it to communicate with host computer 4510 and with UE 4530. Hardware 4525 may include communication interface 4526 for setting up and maintaining a wired or wireless connection with an interface of a different communication device of communication system 4500, as well as radio interface 4527 for setting up and maintaining at least wireless connection 4570 with UE 4530 located in a coverage area (not shown in Fig. 15) served by base station 4520. Communication interface 4526 may be configured to facilitate connection 4560 to host computer 4510. Connection 4560 may be direct or it may pass through a core network (not shown in Fig. 15) of the telecommunication system and / or through one or more intermediate networks outside the telecommunication system. In the embodiment shown, hardware 4525 of base station 4520 further includes processing circuitry 4528, which may comprise one or more programmable processors, application-specific integrated circuits, field programmable gate arrays or combinations of these (not shown) adapted to execute instructions. Base station 4520 further has software 4521 stored internally or accessible via an external connection.

[0306] Communication system 4500 further includes UE 4530 already referred to. Its hardware 4535 may include radio interface 4537 configured to set up and maintain wireless connection 4570 with a base station serving a coverage area in which UE 4530 is currently located. Hardware 4535 of UE 4530 further includes processing circuitry 4538, which may comprise one or more programmable processors, application-specific integrated circuits, field programmable gate arrays or combinations of these (not shown) adapted to execute instructions. UE 4530 further comprises software 4531, which is stored in or accessible by UE 4530 and executable by processing circuitry 4538. Software 4531 includes client application 4532. Client application 4532 may be operable to provide a service to a human or non-human user via UE 4530, with the support of host computer 4510. In host computer 4510, an executing host application 4512 may communicate with the executing client application 4532 via OTT connection 4550 terminating at UE 4530 and host computer 4510. In providing the service to the user, client application 4532 may receive request data from host application 4512 and provide user data in response to the request data. OTT connection 4550 may transfer both the request data and the user data. Client application 4532 may interact with the user to generate the user data that it provides.

[0307] It is noted that host computer 4510, base station 4520 and UE 4530 illustrated in Fig. 14 may be similar or identical to host computer 4430, one of base stations 4412a, 4412b, 4412c and one of UEs 4491, 4492 respectively. This is to say, the inner workings of these entities may be as shown in Fig. 20 and independently, the surrounding network topology may be that of Fig. 15.

[0308] In Fig. 15, OTT connection 4550 has been drawn abstractly to illustrate the communication between host computer 4510 and UE 4530 via base station 4520, without explicit reference to any intermediary devices and the precise routing of messages via these devices. Network infrastructure may determine the routing, which it may be configured to hide from UE 4530 or from the service provider operating host computer 4510, or both. While OTT connection 4550 is active, the network infrastructure may further take decisions by which it dynamically changes the routing (e.g., on the basis of load balancing consideration or reconfiguration of the network).

[0309] Wireless connection 4570 between UE 4530 and base station 4520 is in accordance with the teachings of the embodiments described throughout this disclosure. One or more of the various embodiments may improve the performance of OTT services provided to UE 4530 using OTT connection 4550, in which wireless connection 4570 forms the last segment. More precisely, the teachings of these embodiments may improve the random access speed and / or reduce random access failure rates and thereby provide benefits such as faster and / or more reliable random access.

[0310] A measurement procedure may be provided for the purpose of monitoring data rate, latency and other factors on which the one or more embodiments improve. There may further be an optional network functionality for reconfiguring OTT connection 4550 between host computer 4510 and UE 4530, in response to variations in the measurement results. The measurement procedure and / or the network functionality for reconfiguring OTT connection 4550 may be implemented in software 4511 and hardware 4515 of host computer 4510 or in software 4531 and hardware 4535 of UE 4530, or both. In embodiments, sensors (not shown) may be deployed in or in association with communication devices through which OTT connection 4550 passes; the sensors may participate in the measurement procedure by supplying values of the monitored quantities exemplified above, or supplying values of other physical quantities from which software 4511, 4531 may compute or estimate the monitored quantities. The reconfiguring of OTT connection 4550 may include message format, retransmission settings, preferred routing etc.; the reconfiguring need not affect base station 4520, and it may be unknown or imperceptible to base station 4520. Such procedures and functionalities may be known and practiced in the art. In certain embodiments, measurements may involve proprietary UE signaling facilitating host computer 4510's measurements of throughput, propagation times, latency and the like. The measurements may be implemented in that software 4511 and 4531 causes messages to be transmitted, in particular empty or 'dummy' messages, using OTT connection 4550 while it monitors propagation times, errors or the like.

[0311] Fig. 16 is a block diagram of example methods implemented in a communication system including a host computer, a base station, and a user equipment. For simplicity of the present disclosure, only drawing references to Fig. 16 will be included in this section. In step 4610, the host computer provides user data. In substep 4611 (which may be optional) of step 4610, the host computer provides the user data by executing a host application. In step 4620, the host computer initiates a transmission carrying the user data to the UE. In step 4630 (which may be optional), the base station transmits to the UE the user data which was carried in the transmission that the host computer initiated, in accordance with the teachings of the embodiments described throughout this disclosure. In step 4640 (which may also be optional), the UE executes a client application associated with the host application executed by the host computer.

[0312] Fig. 17 is a block diagram of example methods implemented in a communication system including a host computer, a base station, and a user equipment. For simplicity of the present disclosure, only drawing references to Fig. 17 will be included in this section. In step 4710 of the method, the host computer provides user data. In an optional substep (not shown) the host computer provides the user data by executing a host application. In step 4720, the host computer initiates a transmission carrying the user data to the UE. The transmission may pass via the base station, in accordance with the teachings of the embodiments described throughout this disclosure. In step 4730 (which may be optional), the UE receives the user data carried in the transmission.

[0313] Fig. 18 is a block diagram of example methods implemented in a communication system including a host computer, a base station, and a user equipment. For simplicity of the present disclosure, only drawing references to Fig. 18 will be included in this section. In step 4810 (which may be optional), the UE receives input data provided by the host computer. Additionally or alternatively, in step 4820, the UE provides user data. In substep 4821 (which may be optional) of step 4820, the UE provides the user data by executing a client application. In substep 4811 (which may be optional) of step 4810, the UE executes a client application which provides the user data in reaction to the received input data provided by the host computer. In providing the user data, the executed client application may further consider user input received from the user. Regardless of the specific manner in which the user data was provided, the UE initiates, in substep 4830 (which may be optional), transmission of the user data to the host computer. In step 4840 of the method, the host computer receives the user data transmitted from the UE, in accordance with the teachings of the embodiments described throughout this disclosure.

[0314] Fig. 19 is a block diagram of example methods implemented in a communication system including a host computer, a base station, and a user equipment. Fig. 19 is a flowchart illustrating a method implemented in a communication system, in accordance with one embodiment. The communication system includes a host computer, a base station and a UE. For simplicity of the present disclosure, only drawing references to Fig. 19 will be included in this section. In step 4910 (which may be optional), in accordance with the teachings of the embodiments described throughout this disclosure, the base station receives user data from the UE. In step 4920 (which may be optional), the base station initiates transmission of the received user data to the host computer. In step 4930 (which may be optional), the host computer receives the user data carried in the transmission initiated by the base station.

[0315] Any appropriate steps, methods, features, functions, or benefits disclosed herein may be performed through one or more functional units or modules of one or more virtual apparatuses. Each virtual apparatus may comprise a number of these functional units. These functional units may be implemented via processing circuitry, which may include one or more microprocessor or microcontrollers, as well as other digital hardware, which may include digital signal processors, DSPs, special-purpose digital logic, and the like. The processing circuitry may be configured to execute program code stored in memory, which may include one or several types of memory such as read-only memory (ROM), random-access memory, RAM, cache memory, flash memory devices, optical storage devices, etc. Program code stored in memory includes program instructions for executing one or more telecommunications and / or data communications protocols as well as instructions for carrying out one or more of the techniques described herein. In some implementations, the processing circuitry may be used to cause the respective functional unit to perform corresponding functions according one or more embodiments of the present disclosure.

[0316] The foregoing description of the specific embodiments will so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and / or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the scope of the disclosure.

[0317] Fig. 20 illustrates an example computing environment 2000 implementing methods and a network node and first and second UEs, as described in Figs. 8-13. As depicted in Fig. 20, the computing environment 2000 comprises at least one data processing module 2006 that is equipped with a control module 2002 and an Arithmetic Logic Unit, ALU, 2004, a plurality of networking devices 2008 and a plurality Input output, I / O devices 2010, a memory 2012, a storage 2014. The data processing module 2006 may be responsible for implementing the methods described in Figs.8-10. For example, the data processing module 2006 may in some examples be equivalent to the controlling circuitry of the network node / UE described above in conjunction with the Figs. 11-13. The data processing module 2006 is capable of executing software instructions stored in memory 2012. The data processing module 2006 receives commands from the control module 2002 in order to perform its processing. Further, any logical and arithmetic operations involved in the execution of the instructions are computed with the help of the ALU 2004.

[0318] The computer program is loadable into the data processing module 2006, which may, for example, be comprised in an electronic apparatus (such as a network node / UE). When loaded into the data processing module 2006, the computer program may be stored in the memory 2012 associated with or comprised in the data processing module 2006. According to some examples, the computer program may, when loaded into and run by the data processing module 2006, cause execution of method steps according to, for example, any of the methods illustrated in Figs. 8-10 or otherwise described herein.

[0319] The overall computing environment 2000 may be composed of multiple homogeneous and / or heterogeneous cores, multiple CPUs of different kinds, special media and other accelerators. Further, the plurality of data processing modules 2006 may be located on a single chip or over multiple chips.

[0320] The algorithm comprising of instructions and codes required for the implementation are stored in either the memory 2012 or the storage 2014 or both. At the time of execution, the instructions may be fetched from the corresponding memory 2012 and / or storage 2014, and executed by the data processing module 2006.

[0321] In case of any hardware implementations various networking devices 2008 or external I / O devices 2010 may be connected to the computing environment to support the implementation through the networking devices 2008 and the I / O devices 2010.

[0322] The embodiments disclosed herein can be implemented through at least one software program running on at least one hardware device and performing network management functions to control the elements. The elements shown in Fig. 20 include blocks which can be at least one of a hardware device, or a combination of hardware device and software module.

Claims

CLAIMS1. A method (800) performed by a network node (202) for communicating with a first User Equipment, UE (204-1) via a relay path (208), the method (800) comprising:- configuring (810, 510) a second UE (204-2) as a relay UE for the first UE (204-1) on the relay path (208), said second UE (204-2) being arranged between the first UE (204-1) and the network node (202) via a first link (306) and a second link (308), respectively; and- transmitting (815, 515) aggregation configuration information for each of the first UE (204-1) and the second UE (204-2), wherein at least a part of the aggregation configuration information is intended for use at each of the first UE (204-1) and the second UE (204-2) in configuring aggregation of transmissions between the first UE (204-1) and the second UE (204-2) in a protocol layer below a Packet Data Convergence Protocol, PDCP, layer of the first UE (204-1).

2. The method (800) according to claim 1, wherein the protocol layer below the PDCP layer of the first UE (204-1) is a Medium Access Control, MAC, layer.

3. The method (800) according to any of the preceding claims, wherein the aggregation configuration information comprises at least one of the following:- configurations of User Plane, UP, and Control Plane, CP, protocol stacks for the first link (306);- configurations of UP and CP protocol stacks for the second link (308);- a first set of configurations for the first UE (204-1);- a second set of configurations for the second UE (204-2);- one or more access link, Uu, identifiers, IDs associated with the first set of configurations and the second set of configurations;- Uplink, UL, resources configured for transmission of at least one Transport Block, TB, from the first UE (204-1) to the network node (202) via the second UE (204-2) on therelay path (208), wherein the at least one TB corresponds to MAC Protocol Data Units, PDUs, of the first link (306); and- a fixed size for the at least one TB.

4. The method (800) according to claim 3, wherein the first set of configurations for the first UE (204-1) comprising at least one of the following:- a radio bearer configuration for Radio Bearers, RBs, or services of the first UE (204- 1) mapped to the relay path (208);- a configuration of each of upper protocol layers for the first UE (204-1), said upper protocol layers comprising a Service Data Adaptation Protocol, SDAP, a PDCP, and a Radio Link Control, RLC; and- a MAC layer configuration for the MAC layer in the first link (306).

5. The method (800) according to any of claims 3-4, wherein the second set of configurations for the second UE (204-2) comprising at least one of the following:- a physical layer configuration for a physical, PHY, layer in each of the first link (306) and the second link (308), wherein the physical layer configuration is for channel processing of a Physical Data Shared Channel, PDCSH and a Physical Uplink Shared Channel, PUSCH on the relay path (208);- a configuration to perform Hybrid Automatic Repeat Request, HARQ, processes on the relay path (208); and- a MAC layer configuration for the MAC layer in each of the first link (306) and the second link (308).

6. The method (800) according to any of claims 4-5, wherein the MAC layer configurations in the first set of configurations and the second set of configurations are the same or overlap with each other.

7. The method (800) according to any of claims 3-6, wherein- the one or more Uu IDs associated with the first set and the second set of configurations are intended for services or logical channels of the first UE (204-1) mapped to the relay path (208), said one or more Uu IDs being shared between the first UE (204-1) and the second UE (204-2) for transmissions and receptions on the relay path (208).

8. The method (800) according to any of claims 3-7, wherein at least one of the one or more Uu IDs associated with the first set and the second set of configurations comprises one or more of:- a Cell Radio Network Temporary Identifier, C-RNTI, when the first UE (204-1) and the second UE (204-2) are enabled to identify a destination of the at least one TB when the at least one TB is to be transmitted towards or received from the network node (202);- a Configured Scheduling - RNTI, CS-RNTI, when the first UE (204-1) and the second UE (204-2) are performing transmissions towards or receptions from the network node (202) on a Uu link using semi-statically allocated resources by the network node (202);- a resume ID or an Inactive RNTI, l-RNTI for the HARQ processes on the relay path (208), when the first UE (204-1) and / or the second UE (204-2) switch from an Radio Resource Control, RRC, inactive state to a RRC connected state, said resume ID or I- RNTI being used to determine a UE context associated with the first UE (204-1) and / or the second UE (204-2);- an UE ID of the first UE (204-1), when a radio channel quality of the direct path (206) between the first UE (204-1) and the network node (202) is greater than a radio channel quality of the second link (308) between the second UE (204-2) and the network node (202); and- an UE ID of the second UE (204-2), when the radio channel quality of the second link (308) between the second UE (204-2) and the network node (202) is greater than theradio channel quality of the direct path (206) between the first UE (204-1) and the network node (202), wherein the UE IDs of the first UE (204-1) and the second UE (204-2) have been assigned by at least one of: the network node (202), the first UE (204-1), and the second UE (204-2).

9. The method (800) according to any of the preceding claims, wherein the at least the part of the aggregation configuration information is intended to cause the first UE (204-1) to perform a first set of functions at the first link (306), said first set of functions comprising at least one of the following:- building the at least one TB based on at least one of: the Uu IDs and the fixed size of the at least one TB, said at least one TB to be transmitted to the network node (202) via the second UE (204-2) on the relay path (208); and- forwarding the at least one TB to the second UE (204-1) over the first link (306).

10. The method (800) according to any of the preceding claims, wherein at least the part of the aggregation configuration information is intended to cause the second UE (204-2) to perform at least a second set of functions at the first link (306) and the second link (308) on the relay path (208), said second set of functions comprising at least one of the following:- performing the HARQ processes on the relay path (208) by managing at least a part of functions of the HARQ processes at the MAC layer and the PHY layer in the second link (306);- transmitting the at least one TB received from the first UE (204-1) to the network node (202) over the second link (308), in accordance with at least one of: the UL resources configured for the transmission of the at least one TB and the fixed size determined for the at least one TB;- mapping each of the at least one TB received from the first UE (204-1) to one of HARQ entities to operate transmissions and retransmissions of the at least one TB over the second link (308);- performing channel processing of the PDSCH and the PUSCH on the relay path (208); and- signaling of a HARQ feedback to the network node (202) over the second link (308).

11. The method (800) according to claim 10, wherein the second set of functions further comprising at least one of the following:- providing at least one service to the upper protocol layers in the second link (308), said at least one service comprising data transferring to the upper protocol layers and radio resource allocation;- mapping between logical and transport channels for the transmissions and the receptions on the relay path (208);- multiplexing of MAC Service Data Units, SDUs onto the at least one TB;- de-multiplexing of the MAC SDUs from the at least one TB;- reporting a schedule of the transmissions on the relay path (208) to the network node (202);- performing error correction of the transmissions through the HARQ processes; and- prioritizing the logical channels on the relay path (208).

12. The method (800) according to any of the preceding claims, wherein the aggregation configuration information further comprises:- a configuration for an adaptation layer to be implemented at the first link (306) on the relay path (208), said configuration causing the adaptation layer to perform one or more of: o adapting a difference between the second and first set of functions performed by the second and first UEs (204-2, 204-1) to achieve thetransmissions or the receptions over the first link (306) and the second link (308); and o managing a difference of functions between different vendors providing the first UE (204-1) and the second UE (204-2); and / or- a configuration for an adaptation layer to be implemented at the second link (308) on the relay path (208).

13. The method (800) according to any of the preceding claims, wherein the step (815, 515) of transmitting the aggregation configuration information comprising:- transmitting, to the first UE (204-1) over a direct path (206), the aggregation configuration information, wherein the aggregation configuration information is transmitted by the first UE (204-1) to the second UE (204-2) over the first link (306); or- transmitting directly, to the first UE (204-1) and the second UE (204-2), the aggregation configuration information.

14. The method (800) according to any of the preceding claims, wherein the step (810, 510) of configuring the second UE (204-2) as the relay UE for the first UE (204-1) is preceded by the steps of:- receiving (501) a first report related to the first UE (204-1), said first report comprising at least one of: assistance information, measurement results, and a request for aggregating transmissions between the first UE (204-1) and the relay UE on the relay path (208);- determining (502), in accordance with the first report, whether to enable the requested aggregation for the first UE (204-1) on the relay path (208);- when it has been determined to enable the requested aggregation for the first UE (204-1) on the relay path (208), determining (503), from the first report, at least one second UE (204-2-204-N) being operable as the relay UE for the first UE (204-1);- receiving (504) a second report related to each of the determined at least one second UE (204-2-204-N), said second report comprising capability information and measurement results related to each of the at least one second UE (204-2-204-N); and- selecting (505), in accordance with evaluation of the second report, the second UE (204-2) from the at least one second UE (204-2 - 204-N) as the relay UE for the first UE (204-1).

15. The method (800) according to claim 14, wherein- the first report related to the first UE (204-1) comprises: o the assistance information identifying at least one of: Quality of Service, QoS, requirements associated with the services of the first UE (204-1), and traffic pattern characteristics and buffer status of the first UE (204-1); and o the measurement results, each measurement result indicating a radio channel quality of the first link (306) between the first UE (204-1) and one of the at least one second UE (204-2- 204-N); and- the second report related to each of the at least one second UE (204-2-204-N) comprises: o the capability information indicating whether said second UE is operable as the relay UE when it is determined to enable the requested aggregation for the first UE (204-1); and o the measurement results indicating a radio channel quality of each of the first link (306) between the first UE (204-1) and said second UE and the second link (308) between said second UE and the network node (202).

16. The method (800) according to any of the preceding claims, wherein the first link (306) is an inter-UE interface and the second link (308) is a Uu interface.

17. A method (900) performed by a first User Equipment, UE (204-1) for managing a communication with a network node (202) via a second UE (204-2) on a relay path (208), the second UE (204-2) being arranged between the first UE (204-1) and the network node (202) via a first link (306) and a second link (308), respectively, the method (900) comprising:- receiving (915) aggregation configuration information; and- based on at least a part of the aggregation configuration information,: o configuring (920) aggregation of transmissions between the first UE (204- 1) and the second UE (204-2) in a protocol layer below a Packet Data Convergence Protocol, PDCP, layer of the first UE (204-1); and o performing (920) a first set of functions at the first link (306).

18. The method (900) according to claim 17, wherein the aggregation configuration information is received from the network node (202) over a direct path (206).

19. The method (900) according to any of claims 17-18, wherein the aggregation configuration information comprises at least one of the following:- configurations of User Plane, UP, and Control Plane, CP, protocol stacks for the first link (306);- configurations of UP and CP protocol stacks for the second link (308);- a first set of configurations for the first UE (204-1);- a second set of configurations for the second UE (204-2);- one or more access link, Uu, identifiers, IDs associated with the first set of configurations and the second set of configurations;- Uplink, UL, resources configured for transmission of at least one Transport Block, TB, from the first UE (204-1) to the network node (202) via the second UE (204-2) on the relay path (208), wherein the at least one TB corresponds to MAC Protocol Data Units, PDUs, of the first link (306); and- a fixed size for the at least one TB.

20. The method (900) according to any of claims 17-19, wherein the first set of functions performed by the first UE (204-1) at the first link (306) comprising at least one of the following:- building the at least one TB based on at least one of: the Uu IDs and the fixed size of the at least one TB, said at least one TB to be transmitted to the network node (202) via the second UE (204-2) on the relay path (208); and- forwarding the at least one TB to the second UE (204-1) over the first link (306).

21. A method (1000) performed by a second User Equipment, UE (204-2) for managing a communication between a first UE (204-1) and a network node (202) a relay path (208), the second UE (204-2) being arranged between the first UE (204-1) and the network node (202) via a first link (306) and a second link (308), respectively, the method (1000) comprising:- receiving (1015), from one of the network node (202) and the first UE (204-1), aggregation configuration information;- based on at least a part of the aggregation configuration information, o configuring (1020) aggregation of transmissions between the first UE (204- 1) and the second UE (204-2) in a protocol layer below a Packet Data Convergence Protocol, PDCP, layer of the first UE (204-1); and o performing (1020) a second set of functions at the first link (306) and the second link (308).

22. The method (1000) according to claim 21, wherein the aggregation configuration information comprises at least one of the following:- configurations of User Plane, UP, and Control Plane, CP, protocol stacks for the first link (306);- configurations of UP and CP protocol stacks for the second link (308);- a first set of configurations for the first UE (204-1);- a second set of configurations for the second UE (204-2);- one or more access link, Uu, identifiers, IDs associated with the first set of configurations and the second set of configurations;- Uplink, UL, resources configured for transmission of at least one Transport Block, TB, from the first UE (204-1) to the network node (202) via the second UE (204-2) on the relay path (208), wherein the at least one TB corresponds to MAC Protocol Data Units, PDUs, of the first link (306); and- a fixed size for the at least one TB.

23. The method (1000) according to any of claims 21-22, wherein the second set of functions performed by the second UE (204-2) at the first link (306) and the second link (308) comprises at least one of the following:- performing Hybrid Automatic Repeat Request, HARQ, processes on the relay path (208) by managing at least a part of functions of the HARQ processes at a Medium Access Control, MAC, layer and a Physical, PHY, layer in the second link (308);- transmitting the at least one TB received from the first UE (204-1) to the network node (202) over the second link (308), in accordance with at least one of: the UL resources configured for the transmission of the at least one TB and the fixed size determined for the at least one TB;- mapping each of the at least one TB received from the first UE (204-1) to one of HARQ entities to operate transmissions and retransmissions of the at least one TB over the second link (308);- performing channel processing of a Physical Data Shared Channel, PDSCH, and a Physical Uplink Shared Channel, PUSCH, on the relay path (208); and- signaling of a HARQ feedback to the network node (202) over the second link (308).

24. The method (1000) according to claim 23, wherein the second set of functions further comprises at least one of the following:- providing at least one service to upper protocol layers in the second link (308), said at least one service comprising data transferring to the upper protocol layers and radio resource allocation, said upper protocol layers comprising Service Data Adaptation Protocol, SDAP, PDCP, and Radio Link Control, RLC;- mapping between logical and transport channels for transmissions and receptions on the relay path (208);- multiplexing of MAC Service Data Units, SDUs onto the at least one TB;- de-multiplexing of the MAC SDUs from the at least one TB;- reporting a schedule of the transmissions on the relay path (208) to the network node (202);- performing error correction of the transmissions through the HARQ processes; and- prioritizing the logical channels on the relay path (208).

25. An apparatus of a network node (202) configured for communicating with a first User Equipment, UE (204-1) via a relay path (208), the apparatus comprising a controlling circuitry (1106) is configured to cause:- configuration of a second UE (204-2) as a relay UE for the first UE (204-1) on the relay path (208), said second UE (204-2) being arranged between the first UE (204-1) and the network node (202) via a first link (306) and a second link (308), respectively; and- transmission of aggregation configuration information for each of the first UE (204- 1) and the second UE (204-2), wherein at least a part of the aggregation configuration information is intended for use at each of the first UE (204-1) and the second UE (204-2) in configuring aggregation of transmissions between the first UE (204-1) and the second UE (204-2) in a protocol layer below a Packet Data Convergence Protocol, PDCP, layer of the first UE (204-1).

26. The apparatus according to claim 25, wherein the controlling circuitry (1106) is further configured to perform the method as defined in any of claims 2-16.T1. A network node (202) comprising the apparatus of any of the claims 25-26.

28. A first User Equipment, UE (204-1) configured for managing a communication with a network node (202) via a second UE (204-2) on a relay path (208), the second UE (204-2) being arranged between the first UE (204-1) and the network node (202) via a first link (306) and a second link (308), respectively, the first UE (204-1) comprising a controlling circuitry (1206) configured to cause:- reception of aggregation configuration information; and- based on at least a part of the aggregation configuration information, o configuring of aggregation of transmissions between the first UE (204-1) and the second UE (204-2) in a protocol layer below a Packet Data Convergence Protocol, PDCP, layer of the first UE (204-1); and o performing of a first set of functions at the first link (306).

29. The first UE (204-1) according to claim 28, wherein the controlling circuitry (1206) is further configured to perform the method as defined in any of claims 17-20.

30. A second User Equipment, UE (204-2) configured for managing a communication between a first UE (204-1) and a network node (202) a relay path (208), the second UE (204-2) being arranged between the first UE (204-1) and the network node (202) via a first link (306) and a second link (308), respectively, the second UE (204-2) comprising a controlling circuitry (1306) configured to cause:- reception of aggregation configuration information from one of the network node (202) and the first UE (204-1); and- based on at least a part of the aggregation configuration information, o configuring of aggregation of transmissions between the first UE (204-1) and the second UE (204-2) in a protocol layer below a Packet Data Convergence Protocol, PDCP, layer of the first UE (204-1); and o performing of a second set of functions at the first link (306) and the second link (308).

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