Role management in relay communications

Abstract

An arrangement for role management in relay communications is disclosed. In relay communications, one user equipment relays communications between a base station and at least one remote user equipment. Initially, the relay user equipment has a better signal to the base station. When the signal changes, a better signal channel can be achieved by switching roles between the relay user equipment and the remote user equipment. This includes detecting that a better signal exists and determining that a change will provide a better signal.

Description

Background Technology

[0001] The following disclosure relates to wireless communication systems. More specifically, the following disclosure relates to role switching in relay-assisted communications.

[0002] In modern telecommunications networks such as LTE (Long Term Evolution) and 5G, UE (User Equipment) relay is used to extend network coverage. This is also known as sidelink relay or sidelink communication. When relaying, a UE acts as a relay device for one or more remote UEs. A remote UE is a UE connected to the network via a relay UE, for example, when it would otherwise be outside network coverage. In relay-assisted communication, the relay UE has a better radio link connection than a remote UE that communicates indirectly with the base station via a relay UE. Therefore, the remote UE can communicate even if it is outside the base station's coverage area.

[0003] However, the situation can change because mobile devices move relative to each other and to the base station. For example, relay user equipment can move out of the base station's coverage area. Summary of the Invention

[0004] An arrangement for role management in relay communication is disclosed. In relay communication, a user equipment (UE) relays communication between a base station and at least one remote UE. Initially, the relay UE has a better signal to the base station. When the signal changes, better communication can be achieved by switching roles between the relay UE and the remote UE. This involves detecting the existence of a better signal and determining that the change will provide the better signal.

[0005] In one aspect, an apparatus includes at least one processor and at least one memory including computer program code. The at least one memory and the computer program code are configured, together with the at least one processor, to cause the apparatus to measure at least one first value; receive at least one second measurement value from a remote user equipment relayed by a user equipment; assess conditions for role-switching between the user equipment and the remote user equipment based on the at least one measured first value and the at least one received second measurement value; transmit a measurement report to a base station when assessing conditions instructing role-switching between the user equipment and the remote user equipment; and receive a role-switching command from the base station.

[0006] Defining the conditions for measurement reports allows the base station to determine whether role switching is beneficial. When role switching is performed in a controlled manner, user equipment using relay communication will experience improved quality of service as uncontrolled drops in the service decrease.

[0007] In one embodiment, at least one memory and computer program code are further configured to use the user device, together with at least one processor, to transmit at least one first value measured and at least one second measurement value received in a measurement report.

[0008] Transmitting at least one first value measured and at least one second value received in the measurement report makes it beneficial for the base station to use them in the decision-making process.

[0009] In one embodiment, at least one memory and computer program code are further configured to use the user device to receive configuration information with at least one processor, wherein the configuration information includes at least one parameter for evaluating conditions for role exchange between the user device and a remote user device.

[0010] Receiving configuration information allows user equipment to appropriately assess whether role switching needs to be performed in a configurable manner, which is beneficial.

[0011] In one embodiment, at least one memory and computer program code are further configured to, together with at least one processor, use the user device to transmit a request to a remote user device to report at least one measurement value to the user device; and to receive at least one second measurement value as a response to the request.

[0012] Relay user equipment can be used to request measurements from one or more remote user equipments, and the results of these measurements can be useful in evaluations.

[0013] In one embodiment, at least one first measurement and at least one second measurement include at least one of the following: the measured power or quality of the reference signal of the serving cell; and the measured power or quality of the reference signal of the neighboring cell.

[0014] In one embodiment, when the measurement of the serving cell performed by the remote user equipment deviates more significantly than the measurement of the serving cell performed by the user equipment, the conditions for instructing a role exchange between the user equipment and the remote user equipment are evaluated.

[0015] In one embodiment, the conditions for instructing a role exchange between the user equipment and the remote user equipment, as well as the conditions for a combined handover between the user equipment and the remote user equipment, are evaluated when the neighboring cell measurement performed by the remote user equipment is better offset than the serving cell measurement performed by the user equipment, and when the neighboring cell measurement performed by the remote user equipment is better offset than the neighboring cell measurement performed by the user equipment.

[0016] In one aspect, a method for a user equipment is disclosed. The method includes: measuring at least one first value; receiving at least one second measurement value from a remote user equipment relayed by the user equipment; assessing conditions for role switching between the user equipment and the remote user equipment based on the measured at least one first value and the received at least one second measurement value; transmitting a measurement report to a base station when assessing conditions instructing role switching between the user equipment and the remote user equipment; and receiving a role switching command from the base station.

[0017] In one aspect, a network element is disclosed. The network element includes at least one processor; and at least one memory including computer program code, the at least one memory and the computer program code being configured, together with the at least one processor, to enable the network element to: transmit configuration information to a user equipment, the configuration information including at least one parameter for evaluating conditions for role-switching between the user equipment and the remote user equipment based on values ​​measured by the user equipment and a remote user equipment relayed by the user equipment; receive from the user equipment a measurement report indicating the conditions for role-switching between the user equipment and the remote user equipment; and transmit role-switching commands to the user equipment and the remote user equipment.

[0018] Transmitting configuration information (including at least one parameter related to role-switching conditions, or a role-switching trigger event between the user equipment and the remote user equipment) to the user equipment relaying the remote user equipment is beneficial because it enables the user equipment to detect the need for role-switching based on its own measurements and measurements collected from the remote user equipment. When role-switching is performed in a controlled and configurable manner, and when uncontrolled dropouts in the service are reduced, user equipment using relay communication will obtain improved quality of service.

[0019] In one embodiment, at least one memory and computer program code are further configured, together with at least one processor, to enable the network element to receive at least one first value measured by the user equipment and at least one second value measured by the remote user equipment in a measurement report.

[0020] Receiving at least one first value measured by a user equipment and at least one second value measured by a remote user equipment in the measurement report makes it beneficial for the base station to use them in the decision-making process.

[0021] In one embodiment, at least one memory and computer program code are further configured, together with at least one processor, to enable network elements to: transmit combined role-switching commands to user equipment and remote user equipment; or transmit individual role-switching commands to user equipment and remote user equipment simultaneously.

[0022] In one embodiment, the measurement report further indicates the conditions for combined handover of user equipment and remote user equipment to neighboring cells, and at least one memory and computer program code are also configured, together with at least one processor, to cause network elements to transmit a request for combined handover to the target base station operating the neighboring cell.

[0023] In one embodiment, at least one memory and computer program code are further configured, together with at least one processor, to enable the network element to: receive an acknowledgment of a request; and, based on the received acknowledgment, transmit a connection reconfiguration message to the user equipment and the remote user equipment, wherein the acknowledgment includes corresponding handover commands for the user equipment and the remote user equipment, and sidelink resources for sidelink communication between the user equipment and the remote user equipment.

[0024] In one aspect, a method for a network element is disclosed. The method includes transmitting configuration information to a user equipment (UE), the configuration information including at least one parameter for evaluating conditions for role-switching between the UE and a remote UE based on values ​​measured by the UE and a remote UE relayed by the UE; receiving from the UE a measurement report indicating the conditions for role-switching between the UE and the remote UE; and transmitting role-switching commands to the UE and the remote UE.

[0025] In one aspect, a network element is disclosed. The network element includes at least one processor; and at least one memory including computer program code, the at least one memory and the computer program code being configured, together with the at least one processor, to cause the network element to: receive from a base station a combined handover request for a user equipment and a remote user equipment relayed by the user equipment to a neighboring cell operated by the network element, wherein the base station is the network element as described above; and transmit an acknowledgment including corresponding handover commands for the user equipment and the remote user equipment, and sidelink resources for sidelink communication between the user equipment and the remote user equipment. Attached Figure Description

[0026] The accompanying drawings, included to provide a further understanding of role management in relay communications and forming part of this specification, illustrate examples and, together with the description, help explain the principles of role management in relay communications. In the drawings:

[0027] Figure 1a This is an example diagram illustrating a typical role swap;

[0028] Figure 1b This is an example diagram illustrating a typical role swap;

[0029] Figure 1c This is an example diagram illustrating a typical role swap;

[0030] Figure 1d This is an example view illustrating the terms used in the following examples;

[0031] Figure 2 This is an example of a signaling diagram illustrating role switching within a cell;

[0032] Figure 3 This is an example of a signaling diagram illustrating role exchange between cells;

[0033] Figure 4 This is an example of a method for a user equipment in relay mode;

[0034] Figure 5 Examples of base station methods; and

[0035] Figure 6 This is an example of a base station method. Detailed Implementation

[0036] Reference will now be made in detail to exemplary embodiments, examples of which are shown in the accompanying drawings.

[0037] The following example generally relates to role switching in telecommunications. Specifically, it relates to Long Term Evolution (LTE) and 5G mobile telecommunications network technologies, also known as New Radio (NR). While LTE and 5G are used as examples, the disclosed principles can also be applied to different cellular radio implementations. Role switching will be discussed in the following disclosure. This involves a scenario where an earlier relay user equipment (RFE) is configured as a remote user equipment (RFE) to communicate with network elements using the earlier RFE as a relay user equipment.

[0038] Figures 1a to 1d The basic settings and terminology used in the following disclosure are explained. Figures 1a to 1d In this context, a car is shown as an example of a user device, but it should be understood that the user device can be the car itself or a mobile device belonging to a passenger within the car.

[0039] exist Figure 1a In the example, the first base station 100 serves the first user equipment 120. The first user equipment 120 relays services to the second user equipment 130 and the third user equipment 140, which are remote user equipments. In the example of Figure 1, the network used can be LTE (Long Term Evolution). Therefore, base station 100 is an eNodeB. The network used can also be 5G, in which case base station 100 is a gNodeB. In the following disclosure, if different network technologies are used, the base station is used to refer to, for example, an eNodeB, a gNodeB, or a similar component.

[0040] Note that the examples shown are for illustrative purposes only and do not limit the user device to only cars and / or passengers in them. Figure 1b Examples also include the use of a second base station 110, because Figure 1b The example illustrates the situation after a role swap involving a handover. However, the role swap described below can also be performed intra-cell, so that the serving base station does not change. An example of the final result of such a role swap is as follows... Figure 1c As shown. In Figure 1a In the example, the cars are moving in the same direction at relatively similar speeds. This scenario is just one example; role reversal can also be applied when user devices are moving at different speeds and even in different directions.

[0041] exist Figure 1a In the example, the first user equipment 120 communicates with the base station 100. Figure 1a In the example, three user equipments (User Equipments) have been configured so that the first User Equipment 120 relays communication between the second User Equipment 130 and the base station 100, and between the third User Equipment 140 and the base station 100. User equipment whose network services are relayed via another User Equipment is referred to as a remote User Equipment. For example... Figure 1a As shown, when a relay user equipment 120 has been set up for the first user equipment 130 and the second user equipment 140, the first user equipment 120 may have the best radio link connection to the base station 100.

[0042] exist Figure 1b In the example, the situation has changed so that the user equipment has moved closer to the second base station 110, which operates in the adjacent cell. Therefore, they are now in a situation where the radio link connection between the third user equipment 140 and the second base station 110 is better than the radio link connection between the first user equipment 120 and the first base station 100. As a result, the radio link conditions between each user equipment and the base station have changed, such that the third user equipment 140 is now a relay user equipment facing the base station 110. The first user equipment 120 and the second user equipment 130 are now remote user equipments.

[0043] Figures 1a to 1b The process in the example may involve switching.

[0044] exist Figure 1c In the middle, it is shown that... Figure 1a Different scenarios. Figure 1cIn the example, the first user equipment 120, the second user equipment 130, and the third user equipment 140 have been moved, such that the best available radio link is now located between the second user equipment 130 and the first base station 100 (i.e., the current serving base station). This results in a role reversal, making the second user equipment 130 a relay user equipment for user equipments 120 and 140. The first user equipment 120 and the third user equipment 140 are now remote user equipments. Since the radio link connection between the second user equipment 130 and the first base station 100 is superior to the radio links between the other user equipments 120 and 140 and the second base station 110, no handover process is required.

[0045] This provides Figure 1d To support the understanding of the following disclosure, it uses the power or strength of reference signals broadcast or unicast within the cell (such as synchronization signal blocks (SSB) or channel state information reference signals (CSI-RS)) as a decisive metric; however, other metrics such as signal quality (e.g., SNR), traffic load, equipment battery level, etc., may also be used.

[0046] Figure 1d The following examples and the communication channels discussed in the claims are illustrated. As in the example above, in Figure 1d In the illustration, base station 100 is the serving base station, and base station 110 is the second base station operating a neighboring cell. The measured power over connection 150 is the value P_s_UE1 in the following example. Furthermore, when the signal properties of the communication channel between serving base station 100 and user equipment 130 are used as a determining metric, it is an example of the first measurement value of the claim. The measured power over connection 152 is the value P_n_UE1 in the following example. Furthermore, when the signal properties of the communication channel between the second base station 110 and user equipment 130 are used as a determining metric, it is also an example of the first measurement value of the claim. The connection measured power over connection 154 is the value P_s_UE2 in the following example. Furthermore, when the signal properties of the communication channel between serving base station 100 and user equipment 140 are used as a determining metric, it is an example of the second measurement value of the claim. The measured power over connection 156 is the value P_n_UE2 in the following example. Furthermore, when the signal properties of the communication channel between the second base station 110 and user equipment 140 are used as a determining metric, it is an example of the second measurement value of the claim. As mentioned above, these values ​​are merely examples and are intended only to provide a more easily understood understanding of what is disclosed below.

[0047] Figure 2An example signaling diagram illustrating intra-cell role switching is shown. The process begins with an RRCReconfiguration message 200 from the base station to UE1, which can then be forwarded to UE2 (202). This message includes configuration for measurement report triggering events R1 and / or R2. Furthermore, message 202 may include configuration for periodic or event-based reporting.

[0048] exist Figure 2 In the example, event R1 indicates that the serving base station is better for the remote UE compared to the current relay UE. As an example, event R1 can be set to P_s_UE2 > P_s_UE1 + offset1, where offset1 is an offset parameter with a positive (possibly null) value. Offsets can be used to reduce the number of role swaps. The effect of offsets is that changes are applied only when the difference is significant. Therefore, a second role swap back to the previous role is not possible. If offsets are used, the magnitude of the offset can be determined by the network operator.

[0049] Event R2 indicates that neighboring base stations are better for remote UEs compared to the serving base station, while for relay UEs, no neighboring base station is better than the serving base station. As an example, event R2 can be set to P_n_UE2>P_sUE1+offset2 and P_s_UE1>P_n(any)_UE1+offset3, where offset2 and offset3 are both offset parameters with positive (possibly null) values, and P_n(any)_UE1 represents the relay UE's measurement against any neighboring cell. Furthermore, the offset2 value is typically higher than the offset3 value.

[0050] Alternatively, event R2 can be triggered when the serving base station is offset more favorably from the current relay UE to the remote UE, i.e., when P_n_UE2>P_s_UE1+offset2, and when the neighboring cell is offset more favorably from the current relay UE to the remote UE, i.e., when P_n_UE2>P_n_UE1+offset4, where offset4 is also an offset parameter with a positive (possibly null) value.

[0051] UE2, acting as a remote user equipment, is configured to perform measurements, such as measuring the radio interface between the remote user equipment and the base station serving UE2, and / or the radio interface between the remote user equipment and one or more neighboring cells, represented by P_s_UE2 and P_n_UE2, respectively. Measurements and reporting can be performed using periodic reports configured by the network or event-triggered reports, which are decoded by UE1 to obtain measurement values ​​from UE2 for evaluation of R1 and / or R2 conditions.

[0052] Alternatively, UE1 can use signal 203 to transmit a request to report one or more measurements related to the serving cell and / or one or more neighboring cells. If UE1 transmits optional message 203, the message may contain only a request to report the latest measurement, or it may contain an explicit request to measure and periodically report the current value. The requested measurement is typically an L3 measurement used to assess the conditions for role switching (possibly with combined handover) between the remote user equipment and the relay user equipment. Alternatively, the reported measurement may be an L1 measurement, in which case some additional L3 filtering is performed at the relay user equipment before assessing the conditions. Furthermore, these L3 or L1 measurements may include timestamps, etc., so that the relay user equipment can determine the relevant set of measurements of the remote user equipment to use when assessing the conditions. In addition, to reduce the signaling load on the sidelink interface, the remote user equipment may begin reporting these L3 or L1 measurements to the relay user equipment after a given condition is met, such as when the signal level of the serving cell (i.e., P_s_UE1) measured by the current relay user equipment drops below a certain threshold.

[0053] Then, the measurement results are sent to UE1 (204). UE1 performs the same measurement and evaluates (206) the received measurement to detect whether the conditions for triggering the R1 and / or R2 measurement reports are met. In another example, based on UE1's measurement of the Uu interface with its serving cell and / or neighboring cells, UE1 can obtain the required Uu measurement at UE2 to trigger R1 and / or R2.

[0054] exist Figure 2 In the example, the condition for R1 has been met, and accordingly, the R1 measurement report is triggered (208). Then, a combined measurement report (210) is sent to the base station. The measurement report may include the values ​​of P_s_UE1 and P_s_UE2. However, instead of reporting these values, only an indication indicating that the condition has been met is sent to the base station. Based on the received information, the base station decides to perform a role swap (212). In one example, this is done by transmitting a single RRCReconfiguration message (214) to UE1, which UE1 forwards (216) to UE2, or it is done by sending two separate RRCReconfiguration messages, one to UE1 and the other (through UE1) to UE2. Finally, the actual role swap is performed (218). At the end of the signaling, UE2 is the new relay user equipment, and UE1 is the new remote user equipment.

[0055] Figure 3 Another example of the role-swapping process has been published. Figure 3The example adds a second base station during role switching. The initial step is to transmit an RRCReconfiguration message from the first base station BS1 to the first user equipment UE1 (step 300). This message also includes measurement report trigger events R1 and / or R2. The first user equipment then forwards this message, at least partially, to the second user equipment UE2 (step 302). Figure 2 In the example, measurement and reporting can be performed using periodic reporting or event-triggered reporting, or UE1 can use signal 303 to transmit a request to report one or more measurement values. If UE1 transmits optional message 303, this message can contain only a request to report the latest measurement value or an explicit request to measure and periodically report the current value. The first user equipment is a relay user equipment, and the second user equipment is a remote user equipment. The second user equipment then performs the necessary measurements. Figure 3 In the example, the measurement could include P_s_UE2, which is a radio interface measurement between the serving base station and a second user equipment associated with the serving cell. Figure 3 In the example, the serving base station is the first base station. The measurement also includes P1_n_UE2, which is the radio interface measurement between the second base station and the second user equipment associated with a neighboring cell operated by the second base station.

[0056] UE1 performs the same measurement, or uses the most recent measurement value, to obtain P_s_UE1 and P_n_UE1, and evaluates the measurement (step 306) to detect whether the conditions triggered by R1 and / or R2 are met. Figure 3In the example, condition R2 has been met, and a corresponding R2 measurement report is triggered (308). Then, in step 310, a measurement report is sent to the first base station, including the measurement results of the corresponding radio link related to event R2. However, instead of reporting these values, only an indication that the condition is met can be sent to the first base station. The first base station decides (step 312) whether both a role switch and a handover are needed to obtain the best possible radio interface quality. Then, in step 314, the first base station sends a handover request to the second base station to request a handover from the first user equipment and the second user equipment to a neighboring cell (also called the target cell). The handover request includes an indication that a role switch is needed between the first user equipment and the second user equipment, and therefore the corresponding sidelink resources should be configured to support relay operations in the neighboring cell. In step 316, the second base station performs admission control to check whether resources can be reserved for the first user equipment and the second user equipment in the neighboring cell, including the sidelink resources required for relay operations, and in step 318, an acknowledgment is made, which includes information required for a combined handover of the first user equipment and the second user equipment to the neighboring cell. The second base station also includes sidelink resources in the confirmation for relaying UE1 (the new remote user equipment) to UE2 (the new relay user equipment) in the neighboring cell. In steps 320 and 322, the first base station relays handover configuration information from the second base station to the first user equipment and the second user equipment as an RRCReconfiguration message. The RRCReconfiguration message (or another RRCReconfiguration message) also includes a role-swapping command for the first user equipment and the second user equipment. As a result, after the handover to the neighboring cell, UE1 will be the remote user equipment, and UE2 will be the relay user equipment (step 324). Finally, the first user equipment, the second user equipment, and the second base station perform the handover using roles according to the settings (step 324).

[0057] In the examples above, only two user equipment (UEs) and a base station were discussed. This is for simplicity only. A relay UE can serve one or more remote UEs. Furthermore, the base station does not need to use the same network technology, but handover can exist between different network technologies with similar sidelink communication involving the relay UE and remote UEs. For example, a handover from LTE to 5G networks, or vice versa, can occur.

[0058] In some implementations, signaling examples disclose signaling that may be preferred. However, in other implementations, some steps may not be necessary to trigger role switching in the presence or absence of a handover. For example, the configuration of events R1 and / or R2 may not be necessary, and the network may rely on current measurement events / reports to collect corresponding radio link connection information for different UEs to trigger role switching in the presence or absence of a handover. For example, each UE may independently report its measurements to the network. Therefore, the network can determine role switching by considering measurement reports received from different UEs.

[0059] exist Figure 4 The document discloses an example of a method for a user equipment (UE) in relay mode. The UE can initiate the method (step 400) by measuring at least one first value. Typically, the measurement includes at least measuring the signal between the UE and the serving cell. However, typically, the UE also measures the signal between the UE and at least one neighboring cell. This measurement can be performed based on an explicit request received from the serving cell, or the UE can decide to perform the measurement. Furthermore, prior to the first step, a configuration message, such as an RRCReconfiguration message, may have been received from the serving cell, which includes additional triggers R1 and / or R2 for role switching.

[0060] Then, the user equipment receives at least one second value measured in step 410 from the user equipment in remote mode. The relay user equipment can receive values ​​from multiple remote user equipments. Furthermore, the remote user equipments can transmit these values ​​periodically, and they do not necessarily arrive at the relay user equipment simultaneously. Additionally, the user equipment can send a request / instruction to one or more remote user equipments to perform measurements of the communication channel between the user equipment and one or more base stations (which may also include the serving base station). The measured and received values ​​are then evaluated to detect whether the conditions for role switching have been met (step 420).

[0061] If the conditions for a role switch have been met, the user equipment transmits a measurement report to the base station (step 430). This measurement includes an indication that the conditions for a role switch have been met. Additionally, the measurement report may include measurement values. Alternatively, the measurement report may contain only measurement values. If the base station determines that a role switch will be performed, the base station sends a role switch command to the user equipment. Finally, the user equipment receives the role switch command (step 440).

[0062] exist Figure 4The example method discussed measurements between user equipment and base stations. However, when one or more user equipments involved are capable of communicating with two or more base stations, more than one communication channel can be measured. Therefore, during evaluation, a request for role switching can be accompanied by measurement results indicating the need for handover. Thus, when needed, the handover process is performed together with role switching, enabling a smooth change of communication channel for all involved user equipments.

[0063] exist Figure 5 The document discloses examples of methods for use with base stations. Figure 5 The example begins with transmitting measurement report configuration to the relay user equipment (step 500). Measurements can be performed based on the examples discussed above. Therefore, they can include several measurements between different user equipment and the base station.

[0064] The base station receives a measurement report that conforms to the configuration of the transmitted measurement report (step 510). If the measurement report indicates a need for role switching, a role switching command can be sent (step 520). Additionally, the base station can perform further evaluation of other additional criteria before deciding on a role switching and transmitting the role switching command.

[0065] exist Figure 6 The document discloses an example of a method for a base station. In this method, firstly, a request for combined handover is received (step 600). This request is received from a base station currently serving the current relay user equipment. The request may also include an indication that a role exchange is required. Then, an acknowledgment is transmitted to the requesting base station (step 610). This acknowledgment includes corresponding handover commands for the user equipment and the remote user equipment, as well as sidelink resources for sidelink communication between the user equipment and the remote user equipment.

[0066] As described above, components of the example embodiments may include a computer-readable medium or memory for storing instructions programmed according to the teachings of the present invention, and for storing data structures, tables, records, and / or other data described herein. The computer-readable medium may include any suitable medium that participates in providing instructions to a processor for execution. Common forms of computer-readable media may include, for example, floppy disks, flexible disks, hard disks, magnetic tape, any other suitable magnetic media, CD-ROM, CD±R, CD±RW, DVD, DVD-RAM, DVD±RW, DVD±R, HD DVD, HDDVD-R, HD DVD-RW, HD DVD-RAM, Blu-ray discs, any other suitable optical media, RAM, PROM, EPROM, FLASH-EPROM, any other suitable memory chip or cartridge, carrier wave, or any other suitable medium from which a computer may read.

[0067] As used in this application, the base station and / or user equipment may include circuitry. The term "circuitry" may refer to one or more, or all of the following:

[0068] (a) Hardware circuit implementation only (such as implementation only in analog and / or digital circuits), and

[0069] (b) A combination of hardware circuitry and software, such as (if applicable):

[0070] (i) A combination of analog and / or digital hardware circuitry with software / firmware, and

[0071] (ii) Any part of a hardware processor (including a digital signal processor), software, and memory that works together to enable a device (such as a mobile phone or server) to perform various functions, and

[0072] (c) Hardware circuitry and / or processors, such as microprocessors or a portion thereof, which require software (e.g., firmware) to operate, but may be absent when the software is not required to operate.

[0073] This definition of "circuit" applies to all uses of the term in this application, including in any claim. As another example, as used herein, the term "circuit" also covers implementations of only hardware circuitry or processors (or processors), or portions of hardware circuitry or microprocessors, and their accompanying software and / or firmware. For example, if applicable to a particular claim element, the term "circuit" also covers baseband integrated circuits or processor integrated circuits for mobile devices, or similar integrated circuits in servers, cellular network devices, or other computing or network devices.

[0074] Examples of applicable access architectures may include radio access architectures based on Advanced Long Term Evolution (LTE-A, or LTE-A) or New Radio (NR, 5G); however, the example embodiments are not limited to such architectures. It will be apparent to those skilled in the art that, by appropriately adjusting parameters and processes, the example embodiments can also be applied to other types of communication networks with suitable components.

[0075] It will be clear to those skilled in the art that the depicted system is merely an example of a portion of a radio access system, and in practice, the system may include multiple (e / g)NodeBs, user equipment may access multiple radio cells, and the system may also include other devices such as physical layer relay nodes or other network elements. At least one of the (e / g)NodeBs may be a home (e / g)NodeB. Furthermore, multiple different types of radio cells and multiple radio cells may be provided within the geographical area of ​​the radio communication system. Radio cells may be macrocells (or umbrella cells), which are large cells, typically with diameters up to tens of kilometers, or they may be smaller cells, such as microcells, femtocells, or picocells. (e / g)NodeBs may provide any of these types of cells. Cellular radio systems can be implemented as multi-layered networks comprising several types of cells. Typically, in a multi-layered network, one access node provides one or more cells, and therefore providing such a network structure requires multiple (e / g)NodeBs.

[0076] It will be apparent to those skilled in the art that, with advancements in technology, the fundamental concept of role management in relay communication can be implemented in various ways. Therefore, role management in relay communication and its exemplary embodiments are not limited to the examples described above; rather, they can vary within the scope of the claims.

Claims

1. A user equipment comprising: at least one processor; and at least one memory including computer program code, the at least one memory and the computer program code configured to, with the at least one processor, cause the user equipment to: measure at least one first value; receive at least one second measurement value from a remote user equipment relayed by the user equipment; evaluate, based on the measured at least one first value and the received at least one second measurement value, a condition for a role exchange between the user equipment and the remote user equipment; when the evaluation indicates that the condition for a role exchange between the user equipment and the remote user equipment and for a combined handover of the user equipment and the remote user equipment towards a neighboring cell is fulfilled, transmit a measurement report to a base station, wherein: when a measurement value of a neighboring cell performed by the remote user equipment is better offset than a measurement value of a serving cell performed by the user equipment and when the measurement value of the neighboring cell performed by the remote user equipment is better offset than a measurement value of the neighboring cell performed by the user equipment, the evaluation indicates that the condition for a role exchange between the user equipment and the remote user equipment and for a combined handover of the user equipment and the remote user equipment towards the neighboring cell is fulfilled; and receive a role exchange command from the base station.

2. The user equipment according to claim 1, wherein the at least one memory and the computer program code are further configured to, with the at least one processor, cause the user equipment to transmit the measured at least one first value and the received at least one second measurement value in the measurement report.

3. The user equipment according to claim 1 or 2, wherein the at least one memory and the computer program code are further configured to, with the at least one processor, cause the user equipment to receive configuration information, wherein the configuration information comprises at least one parameter for evaluating the condition for a role exchange between the user equipment and the remote user equipment.

4. The user equipment according to claim 1 or 2, wherein the at least one memory and the computer program code are further configured to, with the at least one processor, cause the user equipment to: transmit a request to a remote user equipment to report at least one measurement value to the user equipment; and receive the at least one second measurement value as a response to the request.

5. The user equipment according to claim 1 or 2, wherein the at least one first measurement value and the at least one second measurement value comprise at least one of: a measured power or quality of a reference signal of a serving cell; and a measured power or quality of a reference signal of a neighboring cell.

6. The user equipment according to claim 1 or 2, wherein the evaluation indicates the condition for a role exchange between the user equipment and the remote user equipment when a measurement value of a serving cell performed by the remote user equipment is better offset than a measurement value of the serving cell performed by the user equipment. ​ 7. A method for a user equipment, comprising: measuring at least one first value; receiving at least one second measured value from a remote user equipment relayed by the user equipment; evaluating, based on the measured at least one first value and the received at least one second measured value, a condition for a role exchange between the user equipment and the remote user equipment; transmitting, to a base station, a measurement report when the evaluation indicates that the condition for a role exchange between the user equipment and the remote user equipment and for a combined handover of the user equipment and the remote user equipment towards a neighbor cell is fulfilled, wherein: the evaluation indicates that the condition for a role exchange between the user equipment and the remote user equipment and for a combined handover of the user equipment and the remote user equipment towards the neighbor cell is fulfilled when a measurement value of a neighbor cell performed by the remote user equipment is better offset than a measurement value of a serving cell performed by the user equipment and when the measurement value of the neighbor cell performed by the remote user equipment is better offset than a measurement value of the neighbor cell performed by the user equipment; and receiving, from the base station, a role exchange command.

8. A network element, comprising: at least one processor; and at least one memory including computer program code, the at least one memory and the computer program code configured to, with the at least one processor, cause the network element to: transmit, to a user equipment, configuration information including at least one parameter for evaluating, based on values measured by the user equipment and by a remote user equipment relayed by the user equipment, a condition for a role exchange between the user equipment and the remote user equipment; receive, from the user equipment, a measurement report when the evaluation indicates that the condition for a role exchange between the user equipment and the remote user equipment and for a combined handover of the user equipment and the remote user equipment towards a neighbor cell is fulfilled, wherein: the evaluation indicates that the condition for a role exchange between the user equipment and the remote user equipment and for a combined handover of the user equipment and the remote user equipment towards the neighbor cell is fulfilled when a measurement value of a neighbor cell performed by the remote user equipment is better offset than a measurement value of a serving cell performed by the user equipment and when the measurement value of the neighbor cell performed by the remote user equipment is better offset than a measurement value of the neighbor cell performed by the user equipment; and transmit, to the user equipment and the remote user equipment, a role exchange command.

9. The network element of claim 8, wherein the at least one memory and the computer program code are further configured to, with the at least one processor, cause the network element to receive, in the measurement report, at least one first value measured by the user equipment and at least one second value measured by the remote user equipment. ​ ​ ​ 10. The network element of claim 8 or 9, wherein the at least one memory and the computer program code are further configured to, with the at least one processor, cause the network element to: transmit a combined role swap command to the user equipment and the remote user equipment; or transmit separate role swap commands to the user equipment and the remote user equipment simultaneously.

11. The network element of claim 8 or 9, wherein the measurement report further indicates conditions for a combined handover of the user equipment and the remote user equipment towards a neighboring cell, the at least one memory and the computer program code are further configured to, with the at least one processor, cause the network element to: transmit a request for a combined handover to a target base station operating the neighboring cell.

12. The network element of claim 11, wherein the at least one memory and the computer program code are further configured to, with the at least one processor, cause the network element to: receive an acknowledgement of the request; and transmit a connection reconfiguration message to the user equipment and the remote user equipment in accordance with the received acknowledgement, wherein the acknowledgement comprises respective handover commands for the user equipment and the remote user equipment, and sidelink resources for sidelink communication between the user equipment and the remote user equipment.

13. A method for a network element, comprising: transmitting configuration information to a user equipment, the configuration information comprising at least one parameter for evaluating conditions for a role swap between the user equipment and a remote user equipment relayed by the user equipment based on values measured by the user equipment and by the remote user equipment; receiving a measurement report from the user equipment when the evaluation indicates that conditions for a role swap between the user equipment and the remote user equipment and for a combined handover of the user equipment and the remote user equipment towards a neighboring cell are met, wherein: the evaluation indicates that conditions for a role swap between the user equipment and the remote user equipment and for a combined handover of the user equipment and the remote user equipment towards the neighboring cell are met when a measured value of the neighboring cell performed by the remote user equipment is better offset than a measured value of a serving cell performed by the user equipment and when the measured value of the neighboring cell performed by the remote user equipment is better offset than a measured value of the neighboring cell performed by the user equipment; and transmitting role swap commands to the user equipment and the remote user equipment.

14. A network element, comprising: at least one processor; and at least one memory including computer program code configured to, with the at least one processor, cause the network element to: receiving, from a base station, a request for a combined handover of a user equipment and a remote user equipment relayed by the user equipment towards a neighbouring cell operated by the network element, wherein the base station is the network element according to any one of claims 8 to 12; transmitting an acknowledgement comprising respective handover commands for the user equipment and the remote user equipment, and sidelink resources for sidelink communication between the user equipment and the remote user equipment.

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