Methods and apparatuses for communicating information relating to resource allocation betweeen a parent network node and a relay node

Abstract

Embodiments described herein relate to methods and apparatuses for communicating information relating to resource allocation between a parent network node and a relay node. A method, performed by a user equipment, UE, wherein the UE forms part of a relay node with a first network node comprises receiving from, or transmitting to, a parent network node in communication with the relay node, information relating to resource allocation, wherein the information is received or transmitted on a radio resource control, RRC, layer.

Description

[0001] METHODS AND APPARATUSES FOR COMMUNICATING INFORMATION RELATING

[0002] TO RESOURCE ALLOCATION BETWEEEN A PARENT NETWORK NODE AND A

[0003] RELAY NODE.

[0004] TECHNICAL FIELD

[0005] Embodiments described herein relate to methods and apparatuses for communicating information relating to resource allocation between a parent network node and a relay node comprising a UE and a first network node.

[0006] BACKGROUND

[0007] Integrated Access and Backhaul (IAB) was introduced in 5thGeneration (5G) 3GPP as the wireless relay solution for multi-hop relays. IAB relies on a Central unit (CU) Distributed unit (DU) split in a base station, which is a form of higher layer split. With the possibility to introduce lower layer split in the 6G, the need to have such a higher layer split is questionable. More importantly, the IAB solution requires implementation of the IAB- Mobile Terminal (MT) with the new Backhaul Adaptation Protocol (BAP) layer. In other words, it is not possible to use an off-the-shelf UE chipset implementation for the MT part of an IAB relay node (as defined in the current standard). This results in additional implementation cost, that has been shown to be significant, and is hindering IAB commercialization.

[0008] Figure 1 illustrates intra device interference at an IAB relay node 100. A relay node 100 may not be able to transmit from one part (i.e. either the MT or the gNB part) whilst also receiving at the other part, due to transmission leakage (as illustrated by the dashed lines).

[0009] One simple solution to this problem may be to provide high quality insulation to prevent the transmission leakage from occurring, but this is not always possible. It will be appreciated that this is a generic issue applicable for all wireless relay nodes.

[0010] However, in some examples, a relay node may still be able to provide some simultaneous operations. For example, in the case of IAB, the node can have simultaneous DU / MT operations where they are operating in different transmission directions, e.g., simultaneous DU and MT transmission, as illustrated in Figure 2a, and alternatively simultaneous DU and MT reception, as illustrated in Figure 2b.

[0011] In this case, it may be ensured that the DU and MT transmissions or receptions take place in different resources, e.g., utilising Frequency Division Multiplexing (FDM) between the DU and MT within a carrier or Spatial Division Multiplexing (SDM) between the DU and MT by using different antenna panels pointing in different directions.

[0012] To address this issue of intra device interference at relay nodes, 5G IAB has introduced various features to coordinate the DU / MT resource allocation. In essence, these features separately configure the DU and the MT for certain transmission direction(s). IAB assumes a very tight interaction between IAB-MT and IAB-DU, in other words, all information received by IAB-DU can be shared with IAB-MT and vice versa, to coordinate resource allocations to avoid intra-node interferences.

[0013] The following presents examples of features introduced by 5G IAB to address intra device interference:

[0014] DU resource configuration

[0015] DU time-domain resources, in addition to whether the resources are downlink, uplink or flexible (either downlink or uplink) (D / U / F), may be configured as “Not Available”, implying that the DU should not use the resource at all.

[0016] In parallel to the D / U / F configuration, particular resources may be configured as “Hard” or “Soft”.

[0017] • In the case of “Hard” configuration, the DU may use the resources without considering the impacts on the MT’s ability to transmit or receive.

[0018] • In the case of “Soft” configuration, the DU may use the resource if and only if this does not impact the MT’s ability to transmit / receive according to its configuration and scheduling.

[0019] Whether or not the “soft” resource may be used may be derived from lAB-node internal implementation (i.e., in the case of a good insulation) or by a dynamic indication from the parent node in Downlink Control Information (DCI) format 2 5. It will be appreciated that this solution requires tight coordination between IAB-MT and IAB-DU. For example, the IAB-MT firstly receives and decodes DCI format 2 5 and indicates to the IAB-DU.

[0020] Over-the-air sync

[0021] An IAB-DU is subject to the same downlink timing alignment of a gNB and over the air (OTA) timing alignment is introduced to support downlink timing alignment.

[0022] The IAB node sets its DU transmission timing Tjorop time ahead of its received timing at the MT side. T prop is the propagation delay between relay node and its parent network node. The value of Tjorop is obtained from the Timing advance (TA) value from the parent network node and an additional T delta parameter signaled via MAC-CE from the parent network node. T delta is the offset between the uplink reception timing and downlink transmission timing at the parent network node.

[0023] SUMMARY

[0024] There is an interest in using infrastructure-based wireless relays, for example for public safety for coverage extension.

[0025] As the use case of the infrastructure-based relay is limited compared to enhanced Mobile Broadband (eMBB) use cases, according to some embodiments, existing baseline components (e.g., off the shelf UE chipset, and a legacy gNB implementation) may be utilised to provide the relay nodes.

[0026] However, to provide a layer 3 relay node with an off-the-shelf UE, it is unclear how to efficiently coordinate the relay nodes in order to avoid intra relay-node interference. IAB architecture is a Layer 2 relay built upon a Radio Link Control (RLC) layer with an additional layer on top of RLC with respect to an off-the-shelf UE, and therefore the solutions therein cannot be directly re-used.

[0027] One existing solution is to exchange information via Xn interfaces between gNBs (e.g. as illustrated above in Figures 2 to 4). However, Xn traffic is treated as User Plane payload in L3 relay solutions, and it would therefore be challenging and have large impacts on a UE chipset implementation if the UE is to be able to intercept and understand the information being exchanged among the gNB components of the relay nodes.

[0028] As specifically illustrated in Figure 4, a UE sees Xn signalling as user-plane IP traffic. Additionally, delivering over the Xn interface results in a large delay as the case for tunneled PDU session, due to the fact that the IP packets carrying the Xn signalling are transferred via tunnel-into-tunnels (as shown in Error! Reference source not found.).

[0029] According to some embodiments there is provided a method, performed by a user equipment, UE, wherein the UE forms part of a relay node with a first network node. The method comprises receiving from, or transmitting to, a parent network node in communication with the relay node, information relating to resource allocation, wherein the information is received or transmitted on a radio resource control, RRC, layer.

[0030] According to some embodiments there is provided a method performed by a parent network node in communication with a relay network node comprising a user equipment, UE. The method comprises receiving from, or transmitting to, the UE, information relating to resource allocation, wherein the information is received or transmitted on a radio resource control, RRC, layer.

[0031] According to some embodiments there is provided a method performed by a first network node, wherein the first network node forms part of a relay node with a user equipment. Te method comprises receiving from, or transmitting to, the UE, information relating to resource allocation, wherein the information is received on or transmitted to an upper layer of the control plane of the UE.

[0032] According to some embodiments there is provided a user equipment configured to form part of a relay node with a first network node. The user equipment comprises processing circuitry and memory, the memory containing instructions executable by the processing circuitry whereby the user equipment is operable to: receive from, or transmit to, a parent network node in communication with the relay node, information relating to resource allocation, wherein the information is received or transmitted on a radio resource control, RRC, layer. According to some embodiments there is provided a parent network node configured to communicate with a relay network node comprising a user equipment. The parent network node comprises processing circuitry and memory, the memory containing instructions executable by the processing circuitry whereby the parent network node is operable to: receive from, or transmit to, the UE, information relating to resource allocation, wherein the information is received or transmitted on a radio resource control, RRC, layer.

[0033] According to some embodiments there is provided a first network node configured to form part of a relay node with a user equipment. The first network node comprises processing circuitry and memory, the memory containing instructions executable by the processing circuitry whereby the first network node is operable to: receive from, or transmit to, the UE, information relating to resource allocation, wherein the information is received on or transmitted to an upper layer of the control plane of the UE.

[0034] According to some embodiments there is provided a computer program, comprising instructions which, when executed on at least one processor, cause the at least one processor to carry out any of the methods described above.

[0035] According to some embodiments there is provided a computer program product comprising non transitory computer readable media having stored thereon a computer program as described above.

[0036] According to some embodiments there is provided a computer-readable medium comprising instructions that, when executed on at least one processor, cause the at least one processor to perform any of the methods described above.

[0037] BRIEF DESCRIPTION OF THE DRAWINGS

[0038] For a better understanding of the embodiments of the present disclosure, and to show how it may be put into effect, reference will now be made, by way of example only, to the accompanying drawings, in which:

[0039] Figure 1 illustrates intra device interference at an IAB relay node;

[0040] Figure 2a illustrates simultaneous DU and MT transmission; Figure 2b illustrates simultaneous DU and MT reception;

[0041] Figure 3 illustrates an example of Layer 3 relay architecture;

[0042] Figure 4 illustrates a system 200 for implementing a tunnelled PDU session to provide communications between a gNB 302b and gNB301 b;

[0043] Figure 5 illustrates paths taken by transport packets for communication from gNB 302b to gNB 301 b and for communication from gNB 301 b to gNB 302b;

[0044] Figure 6 illustrates a partial protocol stack view for the communication between relay node 302 and relay node 301 using the tunelled L3 relaying depicted in Figure 5;

[0045] Figure 7 illustrates a system comprising two relay nodes according to some embodiments;

[0046] Figure 8 is a flowchart illustrating a method performed by a user equipment, UE according to some embodiments;

[0047] Figure 9 is a flowchart illustrating a method performed by a parent network node in communication with a relay network node comprising a user equipment, UE according to some embodiments;

[0048] Figure 10 is a flowchart illustrating a method performed by a first network node;

[0049] Figure 11 is a signaling diagram illustrating an example implementation of the methods of Figures 8 to 10;

[0050] Figure 12 is a signalling diagram illustrating an example implementation of the methods of Figures 8 to 10;

[0051] Figure 13 illustrates a partial protocol stack view for the communication between a first relay node 701 (comprising the parent network node 701 b) and a second relay node 702according to some embodiments; Figure 14 illustrates a UE comprising processing circuitry (or logic);

[0052] Figure 15 is a block diagram illustrating a UE according to some embodiments;

[0053] Figure 16 illustrates a network node comprising processing circuitry (or logic);

[0054] Figure 17 is a block diagram illustrating a parent network node according to some embodiments;

[0055] Figure 18 is a block diagram illustrating a first network node according to some embodiments

[0056] DETAILED DESCRIPTION

[0057] 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 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 may be applied to any other embodiment, wherever appropriate. Likewise, any advantage of any of the embodiments may apply to any other embodiments, and vice versa. Other objectives, features and advantages of the enclosed embodiments will be apparent from the following description.

[0058] The following sets forth specific details, such as particular embodiments or examples for purposes of explanation and not limitation. It will be appreciated by one skilled in the art that other examples may be employed apart from these specific details. In some instances, detailed descriptions of well-known methods, nodes, interfaces, circuits, and devices are omitted so as not obscure the description with unnecessary detail. Those skilled in the art will appreciate that the functions described may be implemented in one or more nodes using hardware circuitry (e.g., analog and / or discrete logic gates interconnected to perform a specialized function, ASICs, PLAs, etc.) and / or using software programs and data in conjunction with one or more digital microprocessors or general purpose computers. Nodes that communicate using the air interface may have suitable radio communications circuitry. Moreover, where appropriate the technology can additionally be considered to be embodied entirely within any form of computer- readable memory, such as (ROM, EEPROM, Flash memory, a memory disc, RAM etc.) solid-state memory, magnetic disk, or optical disk containing an appropriate set of computer instructions that would cause a processor to carry out the techniques described herein.

[0059] Hardware implementation may include or encompass, without limitation, digital signal processor (DSP) hardware, a reduced instruction set processor, hardware (e.g., digital or analogue) circuitry including but not limited to application specific integrated circuit(s) (ASIC) and / or field programmable gate array(s) (FPGA(s)), and (where appropriate) state machines capable of performing such functions.

[0060] Certain aspects of the present disclosure and their embodiments may provide solutions to these or other challenges.

[0061] Particular embodiments are described more fully with reference to the accompanying drawings. Other embodiments, however, are contained within the scope of the subject matter disclosed herein. The disclosed subject matter should not be construed as limited to only the embodiments set forth herein; rather, these embodiments are provided by way of example to convey the scope of the subject matter to those skilled in the art.

[0062] Figure 3 illustrates an example of Layer 3 relay architecture. A parent relay node 301 comprises a UE 301 a and a gNB 301 b. The child relay node 302 then comprises a UE 302a and a gNB 302b. It will be appreciated that communications being transmitted from the parent relay node 301 to the child relay node 302 will be transmitted from the gNB part 301 b to the UE part 301 a.

[0063] For transmissions of information from the gNB 301 a to the gNB 302a, a tunnelled Packet Data Unit (PDU) session may be used.

[0064] Figure 4 illustrates a system 400 for implementing a tunnelled PDU session to provide communications between a gNB 302b and gNB301 b. The principle is that Internet Protocol (IP) connectivity between the relay nodes may be realized by an IP PDU session which is tunnelled in the relay node’s 301 upstream nodes’ IP PDU sessions.

[0065] For the information transmitted by the base station 302b to reach the base station 301 b in relay node 301 , the IP packets need to first reach the relevant UPF 303 in the core network.

[0066] Figure 5 illustrates paths taken by transport packets in the system 400 for communication from gNB 302b to gNB 301 b and for communication from gNB 301 b to gNB 302b.

[0067] For communication from gNB 302b to gNB 301 b utilising the Xn interface means that the traffic passes as follows:

[0068] XnAP gNB 302b -> UE 302a -> gNB 301 b -> UE301 a -> gNB donor 304b -> UPF donor 305 -> UPF 303 -> UPF donor 305 -> gNB donor 304b -> UE 301 a -> XnAP gNB 301 b.

[0069] For communication from gNB 301 b to gNB 302b utilising the Xn interface means that the traffic passes as follows:

[0070] XnAP gNB 301 b -> UE 301 a -> gNB donor 304b -> UPF donor 305 -> UPF 303 -> UPF donor 305 -> gNB donor 304b -> UE 301 a -> gNB 301 b -> UE 302a -> XnAP gNB 302b.

[0071] Figure 6 illustrates a partial protocol stack view for the communication between relay node 302 and relay node 301 using the tunelled L3 relaying depicted in Figure 5.

[0072] The following standardised protocol layers are illustrated:

[0073] GPRS Tunnelling Protocol User Plane (GTP-U)

[0074] Xn Application Protocol (Xn-AP)

[0075] Internet Protocol (IP)

[0076] Service Data Adaptation Protocol (SDAP)

[0077] Packet Data Convergence Protocol (PDCP)

[0078] Radio Link Control (RLC) Medium Access Control (MAC)

[0079] Physcial Layer (PHY)

[0080] It will be appreciated, as that by utilising the tunnelled PDU session (as illustrated in Figures 4 and 5) there is a requirement to route the traffic through to the UPF for the Xn interface, that the traffic routing illustrated in Figure 5 is inefficient. For example, for two adjacent child-parent relay nodes, Xn traffic needs to reach the UPF donor and other UPFs and then return back to the destination relay node.

[0081] Embodiments described herein leverage the radio resource control (RRC) layer to transmit information between a parent network node and a relay node. In some embodiments described herein, the RRC layer is utilised to communicate information relating to resource allocation between a UE of a first relay node and a parent network node. By utilising the RRC layer, the UE part of the relay node may be able to understand and act upon the information being transmitted between the relay nodes, which introducing greater flexibility in how the resource allocation management may be approached (as will be described in more detail below). Furthermore, utilising the RRC avoids the need for the traffic to be routed to the core network (e.g. the UPF) as illustrated in Figures 4 and 5.

[0082] After receiving this information, the UE may then deliver the information to an upper control plane layer (e.g. the non-access stratum (NAS) layer, RRC layer or an external exposure Application Programming Interface (API)) for communicating at least part of the information to the base station part of the first relay node.

[0083] Figure 7 illustrates a system comprising two relay nodes according to some embodiments.

[0084] The first relay node 701 comprises a UE 701 a and a network node 701 b. The second relay node 702 comprises a UE 702a and a network node 702b. The first relay node 701 may be in communication with network nodes 703 having a wired connection. The second relay node 702 may be in communication with one or more UEs or other relay nodes. It will be appreciated that the network nodes 701 b and 702b may comprise an equivalence of a legacy network node (e.g., gNB) that may be used to communicate with down-stream nodes (including devices (e.g., UEs) and other relay nodes).

[0085] The UEs 701 a and 702a may comprise an equivalence of a device (e.g., UE) and may be used to communicate with up-stream nodes (including network nodes and other relay nodes). It will be appreciated that UE here may not refer to a mobile phone, but could for example be a chipset implementation of a legacy UE with potentially external antennas and power amplifiers. In what follows, the term first network node and the term UE are used to denote entities at the relay node that have the interfaces to the downstream nodes and the interface to the up-stream nodes, respectively.

[0086] Note that additionally components and / or changes to the gNB and / or UE parts of the relay nodes may be needed to support various alternatives of L3 relay nodes. Since these additional components and / or changes are not essential and not required to understand the embodiments described herein, they have been omitted for clarity.

[0087] Figure 8 is a flowchart illustrating a method performed by a user equipment, UE. The UE forms part of a relay node with a first network node. For example, the UE may comprise the UE 702a illustrated in Figure 7 or the UE 701 a illustrated in Figure 7.

[0088] In step 801 the UE receives from, or transmits to, a parent network node in communication with the relay node, information relating to resource allocation, wherein the information is received or transmitted on a radio resource control, RRC, layer. The parent network node may comprise a part of another relay node. For example, the parent network node may comprise the network node 701 b when the UE comprises the UE 702a. Alternatively the parent network node may comprise a network node having a wired connection. For example, the parent network node may be network node 703 when the UE is UE 701 a.

[0089] The information may comprise an indication of resource allocation on a link between the UE and the parent network node. Additionally, or alternatively, the information may comprise an indication of resource allocation on a link with the first network node that is capable of interfering with a link between the UE and the parent network node. In some examples, as the information is either received on the RRC layer from the parent network node (as will be described in more detail with reference to Figure 9), or received at the upper layers of the control plane in the UE from the first network node (as will be described in more detail with reference to Figure 10) and the UE is therefore able to decode and act upon the information, the UE may perform step 802 in which the UE performs an operation in response to receiving the information.

[0090] In some examples, the operation of step 802 may comprise one or more of entering a sleep mode; turning off one or more radios at the UE; and preventing one or more uplink or downlink transmissions by the UE.

[0091] As will be described in more detail with reference to Figures 1 1 and 12, the operation performed may be enacted to avoid or reduce interference between a link with the first network node and a link between the UE and the parent network node. In other embodiments, the operation performed may be enacted to reduce power consumption of the UE when a link between the UE and the parent network node is not being used.

[0092] In addition to the information relating to resource allocation, the method of Figure 8 may further comprise receiving further information from or transmitted to the parent network node.

[0093] For example, the further information may comprise a message authentication code with Octet String. This message authentication code may prevent the UE from modifying the content of the information received in step 801 . The UE may in some examples transmit the message authentication code to the upper layer of the UE for communication to the first network node. The UE may or may not utilize this message authentication node to verify the integrity of the information.

[0094] After the first network node receives this message authentication code, if the integrity checks pass, then the first network node considers the resource allocation information from the parent network node as valid. Otherwise, it ignores the information. This use of such a message authentication code prevents the UE from tampering with the information.

[0095] Figure 9 is a flowchart illustrating a method performed by a parent network node in communication with a relay network node comprising a user equipment, UE. The UE forms part of a relay node with a first network node. For example, the UE may comprise the UE 702a illustrated in Figure 7 or the UE 701 a illustrated in Figure 7. The parent network node may comprise a part of another relay node. For example, the parent network node may comprise the network node 701 b when the UE comprises the UE 702a. Alternatively the parent network node may comprise a network node having a wired connection. For example, the parent network node may be network node 703 when the UE is UE 701 a.

[0096] In step 901 the method comprises receiving from, or transmitting to, the UE, information relating to resource allocation, wherein the information is received or transmitted on a radio resource control, RRC, layer. It will be appreciated that step 901 corresponds to step 801 of Figure 8. The information may therefore be defined as describe with reference to Figure 8.

[0097] Figure 10 is a flowchart illustrating a method performed by a first network node. The first network node may for example comprise the network node 701 b in Figure 7 or the network node 702b in Figure 7. The first network node forms part of a relay node with a user equipment. The UE may for example comprise the UE 701 a or the UE 702a illustrated in Figure 7.

[0098] In step 1001 the method comprises receiving from, or transmitting to, the UE, information relating to resource allocation, wherein the information is received on or transmitted to an upper layer of the control plane of the UE. In some examples, when step 1001 comprises transmitting the information to the UE, at least part of the information transmitted to the UE may be passed on to a parent network node (e.g. step 801 of Figure 8). In other examples, when step 1001 comprises receiving the information from the UE, the information may have been received at the UE from a parent network node (e.g. step 801 of Figure 8).

[0099] The upper layer of the control plan may comprise one of: a NAS layer; a RRC layer; and a control plane layer which extends functionalities of the RRC layer to allow interactions between the RRC layers of the UE and the RRC layer of the first network node.

[0100] The information of step 1001 may be similarly defined as described with reference to Figure 8. Figure 11 is a signaling diagram illustrating an example implementation of the methods of Figures 8 to 10. For illustration purposes, in this example the UE is assumed to be in the UE 702a, the first network node is assumed to be the network node 702b, and the parent network node is assumed to be the network node 701 b. However, it will be appreciated that in some examples, the parent network node does not for part of a relay node.

[0101] In step 1101 , a UE 702a receives from a parent network node 701 b in communication with the relay node 702, information relating to resource allocation, wherein the information is received on a radio resource control, RRC, layer. Step 1101 comprises an example implementation of step 801 of Figure 8 and step 901 of Figure 9.

[0102] The information may comprise an indication of resource allocation on a link between the UE 702a and the parent network node 701 b. For example, the information may be indicative of how the parent network node 701 b is scheduling transmissions on the link between the UE 702a and the parent network node 701 b.

[0103] The information received in step 1101 may comprise some information that can be used in a UE configuration in order to preserve energy at the UE 702a. The information received in step 1101 may also, in some examples, further comprise information that may be used in a network node configuration at the first network node 702b in order to avoid or reduce intra relay node interference.

[0104] The information may be received at the UE 702a in step 1 101 as an information element IE in an RRC message transmitted by the parent network node 701 b to the UE.

[0105] The following indicates possible RRC messages that may comprise such an IE:

[0106] • DLlnformationTransfer: In the current RRC spec, the Downlink (DL) information transfer procedure is initiated by the parent network node (e.g. gNB) whenever there is a need to transfer Non-Access Stratum (NAS) dedicated information. This message may be further expanded to allow for the transfer of the information related to resource allocation as referred to in step 1101. It can be further specified that when such an information is included in DLlnformationTransfer, that this RRC message it to be transmitted in SRB2 (e.g., after security activation). • RRCReconfiguration: The IE comprising the information of step 1 101 may be included in the DL RRC (re)-configuration message of a target gNB node (acting as the parent network node), e.g., during handover of the relay node comprising the UE from a source gNB node to the target gNB node. In comparison to the DLlnformationTransfer message (which is sent after a successful handover), this may allow for a faster transmission of the information of step 1 101 in conjunction with performing the handover. In other words, the information will be available at the relay node as soon as the handover is considered successful.

[0107] • In one alternative, the information of step 1 101 is transmitted by the parent network node in a separately defined RRC message. This approach does not have to inherit implicit requirements / procedures from the known RRC messages. For example, generally DLlnformationTransfer can be transmitted in SRB1 or SRB2, however, in order to contain the information of step 1 101 this feature may need to be restricted and the a DLlnformationTransfer message may be limited to being transmitted in SRB2 only (i.e. , after security activation).

[0108] • In some examples, at least part of the information of step 1 101 may be transmitted in a common configuration (e.g., broadcasted in a SIB (i.e., SIB 2, SIB3, ... SIB x) within the RRC message Systeminformation that applies for all UEs or in MIB or in SIB1 ) while another part of the information may be transmitted in a dedicated RRC message for the specific UE. Which parts of the information of step 1 101 may be transmitted in common or dedicated messages is further described later when examples of information are provided.

[0109] In step 1102 the UE 702a may perform an operation in response to receiving the information. It will be appreciated that step 1 102 is enabled because the information is received on the RRC layer and therefore the UE 702a is able to decode and process the information. Step 1 102 comprises an example implementation of step 802 of Figure 8.

[0110] Depending on the information received in step 1101 , different operations may be performed by the UE 702a. In particular, the UE 702a may perform an operation to reduce power consumption of the UE 702a when a link between the UE 702a and the parent network node 701 b is not being used.

[0111] The following gives four examples of types of information received in step 1101 , and corresponding operations that the UE 702a may perform in step 1 102. In this example, the information in step 1101 indicates that the parent network node 701 b does not intend to communicate (e.g. by either transmission nor reception) with the UE 702a at a particular resource region, e.g., time-frequency resource region in the format of slot or a subset of slots for a range of frequency resources. The operation the UE 702a may then perform in step 1 102, may comprise the UE 702a turning-off its radios or even processors (for example, going into a sleep state) to save energy. In this example, the information may be transmitted to the UE 702a in a common configuration (e.g. broadcast or multicast to multiple UEs). For example, it may be applied for all UEs served by the parent network node 701 b. In one alternative, the information may be applicable to all UEs that are used to construct a relay node, but not applicable to other UEs served by the parent network node 701 b (e.g., used for smart phones).

[0112] In this example, the information of step 1 101 indicates that the parent network node 701 b does not intend to transmit to the UE 702a during a particular resource region. The operation performed by the UE 702a in step 1102 may then be that the UE 702a cancels processing of any of the pre-configured DL transmissions from the parent network node 701 b during the particular resource region, for example any pre-configured DL Semi- Persistent Scheduling (SPS), periodic Channel State Information Reference Signal (CSI- RS) transmissions, SSB receptions and etc. The UE 702a may also stop Physical Downlink Control Channel (PDCCH) monitoring during the particular resource region.

[0113] In this example, the information of step 1101 may indicate that the parent network node 701 b does not intend to receive transmissions from the UE 702a at a particular resource region. The operation performed by the UE 702a in step 1 102 may then be that, for the particular resource region, the UE 702a cancels any of the pre-configured Uplink (UL) transmissions to the parent network node, e.g., any pre-configured UL grants, periodic CSI-RS reporting, etc.

[0114] In this example, the information of step 1 101 may comprise an indication of an offset between the uplink reception timing and downlink transmission timing at the parent network node. Upon the UE receiving this information, the operation performed by the UE in step 1 102 may be the UE forwarding the offset together with a timing advance (TA) value associated with the parent network node (e.g. the TA value of the TAG (timing advance group) that contains the parent network node) to an upper layer of the control plane at the UE. The upper layer of the control plane may then forward the information to the first network node.

[0115] Herein, unless explicitly indicated, a resource region may refer to any orthogonal resources that UE / parent network node may transmit on without being significantly impacted by other transmitters, e.g., different time-frequency resources, different antenna panels pointing in different direction, or different layers in a Multiple Input Multiple Output (MIMO) scheme.

[0116] In step 1 103, in this example, the UE transmits at least part of the information to the first network node. An upper layer of the control plane of the UE may be utilized to transmit the at least part of the information to the first network node. It will be appreciated that step 1103 comprises an example implementation of step 1001 of Figure 10. In some examples, the upper layer of the control plane of the UE may comprise or be coupled to an external exposure API utilised to pass the at least part of the information not the first network node. In another alternative, the information is delivered to the NAS layer of the UE, and the NAS layer then delivers to an external exposure API, which is further used by the first network node to obtain the at least part of the information.

[0117] For clarification, the information received in step 1 101 may include both information for use in configuring the UE and information for use in configuring the first network node. In this case, the UE may take and apply the information useful for UE related configuration and understands which part of the received information may be provided to the first network node. In other examples, the UE may pass all of the information received in step 1 101 on to the first network node in step 1 103.

[0118] In some examples, step 1 103 is performed responsive to receiving an instruction from the parent network node to transmit the information to the first network node. For example, a Boolean flag may be included alongside the information received in step 1101 indicating whether the UE should pass the information (or at least part of the information) on to the first network node. In other examples, the instruction may be comprises within a specific message (e.g. ""RRC Configuration forward”). In other examples, the UE may be configured to automatically perform step 1 103 after receipt of the information in step 1101.

[0119] In step 1 104, the first network node may perform an operation in response to the information received in step 1103.

[0120] It will be appreciated, that similarly to as with step 1 102, the operation performed by the first network node may be dependent on the information received in step 1103.

[0121] The following gives two examples of types of information received by the first network node in step 1 103, and a corresponding operation that the first network node may perform in step 1 104.

[0122] In this example, the information in step 1 103 indicates that the parent network node does not intend to communicate (e.g. by either transmission nor reception) with the UE at a particular resource region, e.g., time-frequency resource region in the format of slot or a subset of slots for a range of frequency resources. The operation performed by the first network node in step 1104 may then be to actively look to schedule transmissions at the particular resource region (as this resource region should be free from intra relay node interference).

[0123] Example 2

[0124] In this example, the information of step 1 103 may comprise an indication of an offset between the uplink reception timing and downlink transmission timing at the parent network node together with a timing advance (TA) value associated with the parent network node (e.g. the TA value of the TAG (timing advance group) that contains the parent network node). The operation performed by the first network node in step 1 104 may then be to compute the propagation time between the relay node and the parent network node and adjust the transmission timing of the first network node accordingly. This is similar to the IAB solution of over the air-time sync. However, the difference is that in embodiments described herein the information is delivered to the UE over RRC while IAB solution delivers over the MAC as an MAC CE. Figure 12 is a signalling diagram illustrating an example implementation of the methods of Figures 8 to 10. For illustration purposes, in this example the UE is assumed to be in the UE 702a, the first network node is assumed to be the network node 702b, and the parent network node is assumed to be the network node 701 b. However, it will be appreciated that in some examples, the parent network node does not for part of a relay node.

[0125] In step 1201 the UE 702a receives, from the first network node 702b forming part of the relay node, information relating to resource allocation, wherein the information is received on an upper layer of the control plane of the UE 702a (e.g. RRC). Step 1201 comprises an example implementation of step 1001 of Figure 10.

[0126] In this example, the information may comprise an indication of resource allocation on a link with the first network node that is capable of interfering with a link between the UE 702a and the parent network node 701 b. For example, the information may be indicative of how the first network node 702b is scheduling transmissions on the link with the first network node 702b.

[0127] The information received in step 1201 may comprise some information that can be used in a UE configuration in order to avoid interference between the link between the UE 702a and the parent network node 701 b and the link with the first network node 702b. The information received in step 1201 may also, in some examples, further comprise information that may be used in a network node configuration at the parent network node 701 b in order to avoid or reduce intra relay node interference.

[0128] In some examples, the first network node 702b generates the information (e.g., as a RRC message, as an Information Element for an RRC message (i.e. , ASN.1 container)), this information (typically carried in a RRC message) is not provided to lower layers (e.g., PDCP) for transmission on the air interface but delivered to the UE 702a at the relay node, e.g., via an gNB exposure API or via directly transmitting to the UE on the control plane upper layer.

[0129] In step 1202 the UE 702a may perform an operation in response to receiving the information. It will be appreciated that step 1202 is enabled because the information is received on the upper layer of the control plane (e.g. over the exposure API interface) and therefore the UE 702a is able to decode and process the information. Step 1202 comprises an example implementation of step 802 of Figure 8. Depending on the information received in step 1201 , different operations may be performed by the UE 702a. In particular, the UE 702a may perform an operation to avoid or reduce interference between the link with the first network node 702b and the link between the UE 702a and the parent network node 701 b.

[0130] In this example, the information received in step 1201 indicates that the first network node 702b intends to transmit (to any of its served nodes) at a particular resource region. The operation performed by the UE 702a in step 1202 may then be to, in the particular resource region, cancel processing of any pre-configured DL transmissions from the parent network node, e.g., pre-configured DL SPS, periodic CSI-RS transmissions, SSB receptions, etc. The UE 702a may additionally or alternatively stop PDCCH monitoring.

[0131] Example 2

[0132] In this example, the information comprises an indication of that the first network node 702b intends to receive transmission (from any of its served nodes) at a particular resource region.

[0133] The operation performed by the UE 702a in step 1202 may then be to, in the particular resource region, cancel any of the pre-configured UL transmissions to the parent network node 701 b, e.g., pre-configured UL grants, periodic CSI-RS reporting, etc.

[0134] In step 1203, in this example, the UE 702a transmits at least part of the information to the parent network node 701 b. The transmission of step 1203 may be performed utilizing the RRC layer. It will be appreciated that step 1203 comprises an example implementation of step 801 of Figure 8 or step 901 of Figure 9. For example, the transmission of step 1203 may be performed in a RRC message via the Uu interface. It will be appreciated that the UE 702a may not transmit all of the information received in step 1201 , and may in some examples not pass on any information to the parent network node.

[0135] For clarification, the information received in step 1201 may include both a part of configuration related to the UE 702a and a part of configuration for parent network node 701 b, in this case, the UE 702a may take and apply the UE related configuration and understands which part of the received information may be provided to the parent network node 701 b. In other examples, the UE 702a may pass all of the information received in step 1201 on to the parent network node 701 b in step 1203.

[0136] In step 1204, in this example, the parent network node 701 b performs an operation in response to receiving the information of step 1203. It will be appreciated that in some examples, the parent network node 701 b may not perform an operation in response to receiving the information of step 1203.

[0137] It will be appreciated, that similarly to as with step 1202, the operation performed by the parent network node 701 b in step 1204 may be dependent on the information received in step 1203.

[0138] The following gives two examples of types of information received by the parent network node 701 b in step 1 103, and a corresponding operation that the parent network node 701 b may perform in step 1104.

[0139] In this example, the information received in step 1201 indicates that the first network node 702b intends to transmit (to any of its served nodes) at a particular resource region.

[0140] The operation that the parent network node 701 b may then perform in step 1204 may be to not schedule DL transmission during the particular resource region to avoid intra-node interferences occurring between the link with the UE 702a and the link to the first network node 702b. The parent network node 701 b may however schedule UL transmissions from the UE 702a that do overlap with the particular resource region whilst still avoiding intra-node interferences, assuming that simultaneous transmission is feasible at the relay node.

[0141] In this example, the information indicates that the first network node 702b intends to receive transmission (from any of its served nodes) at a particular resource region. The operation the parent network node 7701 b may then perform in step 1204 may be to not schedule UL transmissions at the particular resource region to avoid intra-node interferences occurring between the link between the parent network node 701 b and the UE 702a and the link to the first network node 702b. The parent network node 701 b may, however, schedule DL transmission to this UE 702a that do overlap with this particular resource region whilst still avoiding intra-node interferences, assuming that simultaneous reception is feasible at the relay node.

[0142] Figure 13 illustrates a partial protocol stack view for the communication between a first relay node 701 (comprising the parent network node 701 b) and a second relay node 702 according to some embodiments. As illustrated in this Figure, the information can be communicated between the parent network node 701 b and the first network node 702b via the UE 702a. In particular, the RRC layer is utilised to pass commiunications between the UE 702a and the parent network node 701 b.

[0143] As described in the background section, the current approach to coordinate resource allocation among gNBs is to exchange information via Xn interface. In comparison to the approach of relaying via Xn interface, the advantages of the proposed solution are that:

[0144] • The UE-part of the relay node may also be aware of the information relating to resource allocation and may further optimize its operation based on the knowledge, e.g., turn-off radios or communications to save energy.

[0145] • The Latency for exchanging the information relating to resource allocation between gNB is shorter compared to utilsiing the Xn interface (in the case of tunneled PDU session) and it involves also less processing (as there less points where signalling needs to be processed to reach its destination).

[0146] Figure 14 illustrates a UE 1400 comprising processing circuitry (or logic) 1401. The processing circuitry 1401 controls the operation of the UE 1400 and can implement the method described herein in relation to an UE 1400. The processing circuitry 1401 can comprise one or more processors, processing units, multi-core processors or modules that are configured or programmed to control the UE 1400 in the manner described herein. In particular implementations, the processing circuitry 1401 can comprise a plurality of software and / or hardware modules that are each configured to perform, or are for performing, individual or multiple steps of the method described herein in relation to the UE 1400. It will be appreciated that the UE 1400 may comprise one or more virtual machines running different software and / or processes. The UE 1400 may therefore comprise, or be implemented in or as one or more servers, switches and / or storage devices and / or may comprise cloud computing infrastructure that runs the software and / or processes.

[0147] Optionally, the UE 1400 may comprise a memory 1403. In some embodiments, the memory 1403 of the UE 1400 can be configured to store instructions (e.g. program code) executable by the processing circuitry 1401 of the UE 1400 whereby the user equipment is operable to perform the method as described herein with reference to Figure 8, and / or with reference to the UE in Figures 1 1 and 12.

[0148] Alternatively or in addition, the memory 1403 of the UE 1400, can be configured to store any requests, resources, information, data, signals, or similar that are described herein. The processing circuitry 1401 of the UE 1400 may be configured to control the memory 1403 of the UE 1400 to store any requests, resources, information, data, signals, or similar that are described herein

[0149] In some embodiments, the UE 1400 may optionally comprise a communications interface 1402. The communications interface 1402 of the UE 1400 can be for use in communicating with other nodes, such as other virtual nodes. For example, the communications interface 1402 of the UE 1400 can be configured to transmit to and / or receive from other nodes requests, resources, information, data, signals, or similar. The processing circuitry 1401 of UE 1400 may be configured to control the communications interface 1402 of the UE 1400 to transmit to and / or receive from other nodes requests, resources, information, data, signals, or similar. The communications interface 1402 can use any suitable communication technology.

[0150] The UE 1400 may be configured operate in the manner described herein in respect of a UE.

[0151] Figure 15 is a block diagram illustrating a UE 1500 according to some embodiments. The UE 1500 comprises a communicating module 1502 configured to receiving from, or transmitting to, a parent network node in communication with the relay node, information relating to resource allocation, wherein the information is received or transmitted on a radio resource control, RRC, layer. The UE 1500 may operate in the manner described herein in respect of a UE. Figure 16 illustrates a network node 1600 comprising processing circuitry (or logic) 1601 . The processing circuitry 1601 controls the operation of the network node 1600 and can implement the method described herein in relation to an network node 1600. The processing circuitry 1601 can comprise one or more processors, processing units, multicore processors or modules that are configured or programmed to control the network node 1600 in the manner described herein. In particular implementations, the processing circuitry 1601 can comprise a plurality of software and / or hardware modules that are each configured to perform, or are for performing, individual or multiple steps of the method described herein in relation to the network node 1600. It will be appreciated that the network node 1600 may comprise one or more virtual machines running different software and / or processes. The network node 1600 may therefore comprise, or be implemented in or as one or more servers, switches and / or storage devices and / or may comprise cloud computing infrastructure that runs the software and / or processes.

[0152] Optionally, the network node 1600 may comprise a memory 1603. In some embodiments, the memory 1603 of the network node 1600 can be configured to store instructions (e.g. program code) executable by the processing circuitry 1601 of the network node 1600 whereby the user equipment is operable to perform the method as described herein with reference to Figure 9, 10 and / or with reference to the parent network node or the first network node in Figures 11 and 12.

[0153] Alternatively or in addition, the memory 1603 of the network node 1600, can be configured to store any requests, resources, information, data, signals, or similar that are described herein. The processing circuitry 1601 of the network node 1600 may be configured to control the memory 1603 of the network node 1600 to store any requests, resources, information, data, signals, or similar that are described herein.

[0154] In some embodiments, the network node 1600 may optionally comprise a communications interface 1602. The communications interface 1602 of the network node 1600 can be for use in communicating with other nodes, such as other virtual nodes. For example, the communications interface 1602 of the network node 1600 can be configured to transmit to and / or receive from other nodes requests, resources, information, data, signals, or similar. The processing circuitry 1601 of network node 1600 may be configured to control the communications interface 1602 of the network node 1600 to transmit to and / or receive from other nodes requests, resources, information, data, signals, or similar. The communications interface 1602 can use any suitable communication technology.

[0155] The network node 1600 may be configured operate in the manner described herein in respect of a network node.

[0156] Figure 17 is a block diagram illustrating a parent network node 1700 according to some embodiments. The parent network node 1700 may be configured to be in communication with a relay network node comprising a user equipment, UE. The parent network node 1700 comprises a communicating module 1702 configured to receive from, or transmit to, a UE in communication with the relay node, information relating to resource allocation, wherein the information is received or transmitted on a radio resource control, RRC, layer. The parent network node 1700 may operate in the manner described herein in respect of a parent network node.

[0157] Figure 18 is a block diagram illustrating a first network node 1800 according to some embodiments. The first network node 1800 may be configured to form part of a relay node with a user equipment. The first network node 1800 comprises a communicating module 1802 configured to receive from, or transmit to, the UE, information relating to resource allocation, wherein the information is received on or transmitted to an upper layer of the control plane of the UE. The first network node 1800 may operate in the manner described herein in respect of a first network node.

[0158] There is also provided a computer program comprising instructions which, when executed on a least one processor (such as the processing circuitry 1401 of the UE 1400 described earlier), cause the processor to carry out at least part of the method(s) described herein. According to some embodiments there is provided a carrier containing the computer program. In some embodiments, the carrier can be any one of an electronic signal, an optical signal, an electromagnetic signal, an electrical signal, a radio signal, a microwave signal, or a computer-readable medium. There is also provided a (for example, tangible and / or non-transient) computer-readable medium comprising instructions which, when executed by at least one processor, cause the at least one processor to perform at least part of the method(s) described herein.

[0159] It should be noted that the above-mentioned embodiments illustrate rather than limit the invention, and that those skilled in the art will be able to design many alternative embodiments without departing from the scope of the appended claims. The word “comprising” does not exclude the presence of elements or steps other than those listed in a claim, “a” or “an” does not exclude a plurality, and a single processor or other unit may fulfil the functions of several units recited in the claims. Any reference signs in the claims shall not be construed so as to limit their scope.

Claims

CLAIMS1 . A method, performed by a user equipment, UE, wherein the UE forms part of a relay node with a first network node, the method comprising: receiving from, or transmitting to, (801) a parent network node in communication with the relay node, information relating to resource allocation, wherein the information is received or transmitted on a radio resource control, RRC, layer.

2. The method as claimed in claim 1 , wherein the information is received from the parent network node (1101 ).

3. The method as claimed in claim 2, wherein the information comprises an indication of resource allocation on a link between the UE and the parent network node.

4. The method as claimed in claim 2 or 3, further comprising:Transmitting (1103) at least part of the information to the first network node.

5. The method as claimed in claim 4 wherein the at least part of the information is transmitted to the first network node from an upper layer in the UE.

6. The method as claimed in claim 5 wherein the upper layer comprises one of: a NAS layer; a RRC layer; and a control plane layer which extends functionalities of the RRC layer to allow interactions between the RRC layers of the UE and the RRC layer of the first network node7. The method as claimed in claim 4 to 6 further comprising transmitting the information to the first network node responsive to receiving an instruction from the parent network node to transmit the information to the first network node.

8. The method as claimed in claim 1 , wherein the information is transmitted to the parent network node (1203).

9. The method as claimed in claim 8, wherein the information comprises an indication of resource allocation on a link with the first network node that is capable of interfering with a link between the UE and the parent network node.

10. The method as claimed in claim 8 or 9 further comprising receiving (1201 ) the information from the first network node.11 . The method as claimed in claim 10 wherein the information is received at an upper layer in the UE.

12. The method as claimed in any preceding claim further comprising: performing (1 102, 1202) an operation in response to receiving the information.

13. The method as claimed in claim 12 when dependent on claim 9, wherein the operation acts to avoid or reduce interference between the link with the first network node and the link between the UE and the parent network node.

14. The method as claimed in claim 12 when dependent on claim 7, wherein the operation acts to reduce power consumption of the UE when the link between the UE and the parent network node is not being used.

15. The method as claimed in any one of claims 8 to 10 wherein the operation comprises one or more of: entering a sleep mode; turning off one or more radios at the UE; and preventing one or more uplink or downlink transmissions by the UE.

16. A method performed by a parent network node in communication with a relay network node comprising a user equipment, UE, the method comprising: receiving from, or transmitting to (901 ), the UE, information relating to resource allocation, wherein the information is received or transmitted on a radio resource control, RRC, layer.

17. The method as claimed in claim 16 wherein the information is transmitted to theUE (1101 ).

18. The method as claimed in claim 17 wherein the information comprises an indication of resource allocation on a link between the parent network node and the UE.

19. The method as claimed in claim 17 or 18 further comprising transmitting an instruction to the UE to transmit the information to a first network node forming part of the relay node.

20. The method as claimed in claim 16 wherein the information is received from the UE (1201 ).21 . The method as claimed in claim 20 wherein the information comprises an indication of resource allocation on a link with the first network node that is capable of interfering with a link between the UE and the parent network node.

22. The method as claimed in claim 20 or 21 further comprising performing (1204) an operation in response to receiving the information.

23. The method as claimed in claim 22 wherein the operation comprises: scheduling transmissions to avoid interference with resource allocation on the link.

24. A method performed by a first network node, wherein the first network node forms part of a relay node with a user equipment, UE, the method comprising: receiving from, or transmitting to (1001), the UE, information relating to resource allocation, wherein the information is received on or transmitted to an upper layer of the control plane of the UE.

25. The method as claimed in claim 24 wherein the information is received from the UE (1103).

26. The method as claimed in claim 25 wherein the information comprises an indication of resource allocation on a link between the UE and a parent network node.

27. The method as claimed in claim 24 wherein the information is transmitting to the UE (1201 ).

28. The method as claimed in claim 27 wherein the information comprises an indication of resource allocation on a link with the first network node that is capable of interfering with a link between the UE and a parent network node.

29. The method as claimed in claim 24 to 28 wherein the upper layer comprises one of: a NAS layer; a RRC layer; and a control plane layer which extends functionalities of the RRC layer to allow interactions between the RRC layer of the UE and the RRC layer of the first network node.

30. A user equipment (1400) configured to form part of a relay node with a first network node, the user equipment comprising processing circuitry (1401 ) and memory (1403), the memory containing instructions executable by the processing circuitry whereby the user equipment is operable to: receive from, or transmit to (801 ), a parent network node in communication with the relay node, information relating to resource allocation, wherein the information is received or transmitted on a radio resource control, RRC, layer.31 . The user equipment as claimed in claim 30 wherein the memory further contains instructions executable by the processing circuitry whereby the user equipment is operable to perform the method as claimed in any one of claims 2 to 15.

32. A parent network node (1601 ) configured to communicate with a relay network node comprising a user equipment, UE, the parent network node comprising processing circuitry (1601 ) and memory (1603), the memory containing instructions executable by the processing circuitry whereby the parent network node is operable to:receive from, or transmit to (901 ), the UE, information relating to resource allocation, wherein the information is received or transmitted on a radio resource control, RRC, layer.

33. The parent network node as claimed in claim 32 wherein the memory further contains instructions executable by the processing circuitry whereby the parent network node is operable to perform the method as claimed in any one of claims 17 to 23.

34. A first network node (1600) configured to form part of a relay node with a user equipment, UE, the first network node comprising processing circuitry (1601 ) and memory, the memory (1603) containing instructions executable by the processing circuitry whereby the first network node is operable to: receive from, or transmit to, (1001 ) the UE, information relating to resource allocation, wherein the information is received on or transmitted to an upper layer of the control plane of the UE.

35. The first network node as claimed in claim 34 wherein the memory further contains instructions executable by the processing circuitry whereby the parent network node is operable to perform the method as claimed in any one of claims 25 to 29.

36. A computer program, comprising instructions which, when executed on at least one processor, cause the at least one processor to carry out a method according to any of claims 1 to 29.

37. A computer-readable medium comprising instructions that, when executed on at least one processor, cause the at least one processor to perform the method according to any of claims 1 to 29.

38. A computer program product comprising non transitory computer readable media having stored thereon a computer program according to claim 36.

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