JP2021029027A - Relay device, control method, and program for transferring signal with routing - Google Patents

Abstract

To enable appropriate signal transfer to a destination in communication via a relay route.SOLUTION: A relay device performs relay communication between a base station device and a terminal device. The relay device receives a signal for the communication transmitted from another device, determines a device to which data included in the received signal is transferred according to first identification information that is included in the received signal and indicates a route via which the data is transferred from the base station device to the terminal device, and transmits, to the determined device, a signal that includes the data and the received signal with second identification information added to indicate a route different from the route indicated by the first identification information.SELECTED DRAWING: Figure 4

Description

The present invention relates to a relay communication control technique for transferring a routed signal.

In the 3rd Generation Partnership Project (3GPP), the NR (New Radio) standard, which is the 5th generation (5G) cellular communication standard, is being formulated. Further, in the NR standard, IAB (Integrated Access and Backhaul) is being studied as a technique for executing backhaul line communication by using a radio resource for a base station device to communicate with a terminal device. In IAB, for example, a line between a 5G base station device (IAB donor) directly connected to a core network and a relay device (IAB node) that provides wireless access to a terminal device, or a line between IAB nodes is wireless. Established by. The IAB donor manages the IAB node that is directly or indirectly connected to the own device, and can recognize which IAB node the terminal device that is not directly connected to the own device is connected to. .. Then, the IAB donor transmits, for example, a packet containing data addressed to the terminal device to the IAB node to which the terminal device is connected, and the IAB node transmits a radio signal including the data to the terminal device. To. Multiple routes may be set up from the IAB donor to the IAB node.

FIG. 1 shows an example of a wireless communication system in which IAB is used. In the example of FIG. 1, for example, a 5G base station device 101 connected to a core network, a relay device A102 that can be directly connected to the base station device 101, and a base station device 101 connected via at least a relay device A102. There are relay devices B103 to F107. In one example, the base station device 101 is an IAB donor and the relay device is an IAB node. Then, when communicating with the terminal device 111, for example, the base station device 101 transfers packets in the order of the relay device A102 from the base station device 101 and the relay device B103 from the relay device A102, and then from the relay device B103. A radio signal including data is transmitted to the terminal device 111. Similarly, the radio signal transmitted from the terminal device 111 is received by the relay device B103, and the packet containing the data is transmitted to the base station device 101 via the relay device A102. A plurality of routes between the base station device 101 and one relay device can be set. For example, the route between the base station device 101 and the relay device F107 is set to [Relay device A102, relay device B103, Three routes are set: a route via the relay device D105], a route via the [relay device A102, the relay device C104, and the relay device D105], and a route via the [relay device A102, the relay device C104, and the relay device E106]. It is possible.

When a plurality of routes can be set, the base station device identifies a relay device that directly communicates with the terminal device, and then determines a route to be used with the relay device. The route to be used is determined by a predetermined criterion such as equalizing the load of a plurality of routes. Non-Patent Document 1 describes the identification information of the node at the end point of the relay (for example, the relay device that directly communicates with the base station device on the uplink and the terminal device on the downlink) and the route used in the relayed packet. It is stated to include identification information. According to this, each relay device can recognize to which node the received packet should be forwarded based on the identification information of the route.

3GPP Contribution, R2-1908363, May 2019

It is assumed that communication cannot be performed on a part of the relay route. For example, the radio quality between the relay device A102 and the relay device B103 in FIG. 1 may deteriorate, and communication may not be able to continue. In this case, the relay device A102 cannot transmit the packet including the identification information of the route passing through the relay device B103 received from the base station device 101 to the relay device B103, and the packet transfer fails. sell.

The present invention provides a technique for appropriately transferring a signal to a destination in communication using a relay transmission line.

The relay device according to one aspect of the present invention is a relay device that relays communication between a base station device and a terminal device, and is a receiving means for receiving a signal transmitted for the communication from another device. Based on the first identification information included in the received signal, which indicates a route to which the data included in the received signal is transferred between the base station apparatus and the terminal apparatus. A signal containing the data to the determination means for determining the device to which the data is transferred and the device to the determined transfer destination, which is different from the route indicated by the first identification information in the received signal. , A transmission means for transmitting a signal to which a second identification information indicating a route to which the data is transferred is added.

According to the present invention, it is possible to appropriately transfer a signal to a destination in communication using a relay transmission line.

It is a figure which shows the configuration example of a wireless communication system. It is a figure which shows the hardware configuration example of a relay device. It is a figure which shows the functional configuration example of a relay device. It is a figure which shows the example of the flow of processing executed by a relay device.

Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. The following embodiments do not limit the invention according to the claims, and not all combinations of features described in the embodiments are essential to the invention. Two or more of the plurality of features described in the embodiments may be arbitrarily combined. In addition, the same or similar configuration will be given the same reference number, and duplicate description will be omitted.

(System configuration)
The wireless communication system of the present embodiment has the configuration as shown in FIG. 1 described above. In this system, as described above, communication between the base station device 101 (IAB donor) and the terminal devices 111-112 can be performed through a relay path including one or more relay devices (IAB nodes). A plurality of these relay routes can be set, and the base station apparatus can determine which route is used for communication. For example, between the base station device 101 and the relay device F107, as described above, the first route via [relay device A102, relay device B103, relay device D105], [relay device A102, relay device C104, relay] Three routes, a second route via the device D105] and a third route via the [relay device A102, the relay device C104, and the relay device E106], can be set. The base station device 101 determines that communication with, for example, the terminal device 112 is executed via the relay device F107, and further, the route between the base station device 101 and the relay device F107 is set to the above three routes. Select from.

The route is newly established, for example, when the base station device establishes a connection with a newly installed relay device, or when the relay device establishes a connection with another newly installed relay device. Set. For example, in response to the newly installed relay device F107 and the establishment of the connection with the relay device E106, the relay device F107 from the base station device 101 via [relay device A102, relay device C104, relay device E106]. The route to is set. Further, depending on the establishment of the connection between the relay device F107 and the relay device D105, the base station device 101 reaches the relay device F107 via [relay device A102, relay device B103, relay device D105]. A route and a route to the relay device F107 via [relay device A102, relay device C104, relay device D105] are set. When a route is set, the relay device included in the route is notified of the identification information of the route. The identification information is associated with information that identifies the devices included in the corresponding route and information that indicates in what order signals should be transferred between the devices, and each relay device. Is remembered in. Each relay device can identify a device (for example, another relay device or base station device) to which the signal is transferred based on the identification information.

When a plurality of lines are established between the two relay devices, the route identification information may include information for identifying the line between the relay devices. For example, when two lines, a line α and a line β, are established between the relay device A102 and the relay device B103, the information for identifying the line (line α or line β) to be used is used as the route identification information. Can be included.

In one example, in the present embodiment, it is assumed that the base station device 101 communicates with the terminal device 112, and in order to perform this communication, a first route via [relay device A102, relay device B103, relay device D105] is selected. It shall be assumed that it was done. In this case, the signal transmitted by the base station device 101 to the terminal device 112 is first transmitted to the relay device A102, and the relay device A102 receives the signal and transfers it to the relay device B103. After that, the relay device B103 transfers the signal received from the relay device A102 to the relay device D105, and the relay device D105 transfers the signal received from the relay device B103 to the relay device F107. Then, the relay device F107 transmits the data included in the received signal to the terminal device 112. In one example, communication between the base station device and the relay device, communication between the relay devices, and communication between the relay device and the terminal device are performed wirelessly.

In the following, an example of the case where the base station device 101 communicates with the terminal device via a plurality of relay devices will be described, but the base station device 101 may or may not be via one relay device. Of course, it is also possible to communicate with the terminal device.

When the base station apparatus 101 transmits a signal through the above-mentioned first route, the base station apparatus 101 has destination information indicating the relay device F107 that directly communicates with the terminal apparatus 112 as the destination, and the route to which the signal should be transferred. It is transmitted including the route identification information indicating a certain first route. Then, when the relay device included in the first path determines that the own device is the destination by checking the destination information, the relay device is transferred based on the information of the terminal device included in the transferred signal. A radio signal including the received data is transmitted to the terminal device. Further, when the relay device determines that the own device is not the destination by checking the destination information, the relay device identifies the device to which the signal is transferred based on the route identification information. For example, in the first path described above, when the relay device B103 receives a signal from the relay device A102, the relay device B103 confirms the destination information included in the signal and determines that the own device is not the destination (relay device F107). To do. Then, the relay device B103 identifies the relay device D105 as a transfer destination device based on the route identification information indicating the first route, and transfers the received signal to the relay device D105. Further, in the first path, when the relay device B103 receives a signal from the relay device D105, the relay device B103 confirms the destination information included in the signal and determines that the own device is not the destination (base station device 101). .. Then, the relay device B103 identifies the relay device A102 as the transfer destination device based on the route identification information indicating the first route, and transfers the received signal to the relay device A102. In this way, communication between the base station device 101 and the terminal device can be executed using the relay path.

Here, for example, when the base station device 101 transmits a signal including the destination information indicating the relay device F107 and the route identification information indicating the first route to the relay device A102, the relay device A102 transmits the signal. It is assumed that a state has occurred in which the information cannot be transferred to the relay device B103. For example, when RLF (Radio Link Failure) occurs in the wireless link between the relay device A102 and the relay device B103, or when the load of the wireless link becomes high and communication with sufficient quality cannot be performed. In addition, this condition can occur. At this time, the relay device A102 may notify the base station device 101 that the first route cannot be used and that another route should be used. Then, the base station device 101 can retransmit the signal using, for example, the above-mentioned second path or the third path that does not use the wireless link between the relay device A102 and the relay device B103. On the other hand, for example, when it is determined that the wireless link cannot be used in the relay device close to the destination in the route in use, when the base station device 101 is notified that the route cannot be used, the signal indicates that the wireless link is not available. In addition to the time it takes to reach the unusable relay device, it takes time for the notification to reach the base station device 101, and the time until the signal is transmitted by another route can be lengthened.

Therefore, in the present embodiment, the relay device is allowed to transfer the signal to another destination to prevent the delay in communication. For example, when the relay device A102 determines that the wireless link with the relay device B103 cannot be used, the signal is transferred to the relay device C104 instead of the relay device B103. However, in this case, since the relay device C104 does not include its own device in the route specified by the route identification information included in the received signal, the transfer destination device cannot be determined by this route identification information. ..

Therefore, in the present embodiment, when the relay device cannot communicate on the route, for example, when RLF occurs on the wireless link with the transfer destination device on the route specified by the route identification information. A device at another transfer destination is determined, and it is allowed to add a second route identification information about another route including the device at the other transfer destination to the signal. For example, when the relay device A102 receives a signal including the first route identification information corresponding to the first path and determines that the received signal cannot be transferred to the relay device B103, the relay device C104 Is determined as the transfer destination device, and the second route identification information regarding the route including the relay device C104 is added to the header of the received signal. The second route identification information is, in one example, information for identifying the above-mentioned second route or third route including the relay device C104. Two second route identification information corresponding to the second route and the third route, respectively, may be added to the header of the received signal.

The relay device may add another route identification information to the received signal even when communication is possible on the route specified by the route identification information, for example. That is, even if the relay device can transfer the signal according to the first route identification information included in the received signal, the relay device adds the second route identification information to the received signal and adds the signal after the information is added. It may be transferred to the transfer destination device. For example, when the relay device A102 receives a signal including the route identification information indicating the second route described above, the relay device A102 adds, for example, another route identification information indicating the third route to the received signal. It can be generated and transmitted to the relay device C104. In this case, since the relay device C104 is included in both the second route and the third route, one of the routes can be selected and the signal can be transferred to the relay device D105 or the relay device E106. The relay device can add route identification information related to a route via its own device, but may add route identification information related to a route not via its own device. For example, the relay device C104 may transfer a signal to which the route identification information of the second route including the own device is added to the relay device D105, or the route identification information of the first route not including the own device. The signal to which is added may be transferred to the relay device D105.

A device that controls communication, such as the base station device 101, may notify each relay device in advance of information on whether or not to allow the addition of identification information. For example, the relay device A102 may add the second route identification information as described above only when the notification permitting the addition of the identification information has been obtained from the base station device 101. Whether or not the route identification information can be added may be determined for each route. For example, the base station device 101 may notify each relay device in advance of information that specifies the route identification information that can be added. Further, the base station device 101 may notify each relay device in advance of information for determining whether or not the addition is possible so that the relay device can determine whether or not the addition is possible for each of the one or more routes. In one example, the information for determining whether or not to add can be information on the radio usage rate in each of one or more routes. In this case, the relay device may determine that the addition is not allowed for the routes including the sections where the radio usage rate is higher than the predetermined value among the additional candidate routes. The information of the predetermined value may also be notified in advance from the base station device 101 to each relay device. Further, the base station device 101 may notify each relay device in advance of only information having a predetermined value. In this case, each relay device compares the radio usage rate of each radio link included in a plurality of route candidates to the own device and the device of the signal destination with its predetermined value, for example, the radio usage rate of each route. It can be determined whether or not the route identification information for each route may be added depending on whether or not is lower than the predetermined value. The relay device may identify the route to be added based on this information and add the route identification information related to the route.

The other relay device that receives the signal to which the route identification information is added identifies the route including the own device from the routes indicated by the two or more route identification information, and next to the own device in the route. Identify the device to which the signal should be transferred. Then, this relay device transmits a signal to the specified device. In this relay device as well, when RLF is generated in the wireless link with the specified device, the additional processing of the route identification information as described above may be executed.

When the route identification information is added, the relay device may notify the device controlling the communication such as the base station device 101 that the route identification information has been added. Further, the information on the reason for adding the route identification information may be notified to the device controlling the communication such as the base station device 101. For example, when the relay device determines that communication on the route identified by the first route identification information included in the received signal is impossible, and as a result, the second route identification information is added, the base station device 101 prevents the route indicated by the first route identification information from being used in the next and subsequent signal transmission opportunities. Further, when the route identification information is added due to the existence of a route having a relatively low radio usage rate, the base station apparatus 101 is added at the next and subsequent signal transmission opportunities for load distribution. The route indicated by the route identification information may be used.

When adding the second route identification information, the relay device may delete the first route identification information included in the received signal. As a result, other devices that have received the signal transferred from the relay device do not need to execute the transfer destination determination process. Information indicating whether or not the deletion of the route identification information is permitted may be notified from the base station apparatus 101. In this case, the relay device deletes the first route identification information only when the deletion of the route identification information is permitted. Further, the relay device acquires, for example, information for determining whether or not to delete the route identification information related to one or more routes from the base station apparatus 101 in advance, and the first route included in the received signal. It may be decided whether or not the identification information should be deleted. Further, when the first route identification information is deleted, the relay device may notify the base station device 101 that the route identification information has been deleted. As a result, the base station apparatus 101 can prevent the route indicated by the first route identification information from being used in the next and subsequent signal transmission opportunities.

(Device configuration)
Subsequently, a hardware configuration example of the relay device that executes the above-described processing will be described with reference to FIG. In one example, these devices include a processor 201, a ROM 202, a RAM 203, a storage device 204, and a communication circuit 205. The processor 201 is a computer including one or more processing circuits such as a general-purpose CPU (central processing unit) and an ASIC (application specific integrated circuit), and is stored in a ROM 202 or a storage device 204. By reading and executing the existing program, the entire processing of the relay device and each of the above-mentioned processing are executed. The ROM 202 is a read-only memory that stores information such as programs and various parameters related to processing executed by the relay device. The RAM 203 is a random access memory that functions as a workspace when the processor 201 executes a program and stores temporary information. The storage device 204 is composed of, for example, a detachable external storage device or the like. The communication circuit 205 is composed of, for example, a circuit for wireless communication. The relay device is configured as a communication circuit 205 for communication with a base station device, another relay device, or a terminal device, and includes, for example, a baseband circuit and an RF circuit for cellular communication, and an antenna. The communication circuit 205 of the relay device may include, for example, a circuit for performing wireless or wired communication for signal transmission for control or the like. Although one communication circuit 205 is shown in FIG. 2, each device may have a plurality of communication circuits.

FIG. 3 shows an example of the functional configuration of the relay device. The relay device includes, for example, a communication unit 301, a route information specifying unit 302, a transfer destination determination unit 303, a transfer control unit 304, and a route information changing unit 305. Further, the relay device may include a setting acquisition unit 306 and a change notification unit 307. It should be noted that these functional units can be realized, for example, by the processor 201 executing the program stored in the ROM 202.

The communication unit 301 is a functional unit for performing wireless communication with a base station device, another relay device, and a terminal device in accordance with the cellular communication standard. The route information identification unit 302 identifies a route to which a signal received from a base station device or another relay device should be transferred, based on the route identification information included in the signal. The transfer destination determination unit 303 determines the device of the signal transfer destination based on the route specified by the route information identification unit 302. For example, the transfer destination determination unit 303 identifies the device to which the signal should be transferred next to the own device in the specified route. In addition, the transfer destination determination unit 303 may not be able to communicate with the device of the transfer destination specified according to the specified route by the wireless link, or there may be a route having a low wireless usage rate in the wireless link to the destination. In some cases, it may be decided to transfer the signal to a device different from the next transfer destination device specified based on the route identification information. The transfer control unit 304 controls the communication unit 301 so as to transfer the received signal to the transfer destination device determined by the transfer destination determination unit 303.

The route information changing unit 305 adds a second route identification information different from the first route identification information included in the received signal to the received signal. This addition is, for example, when communication cannot be performed on the wireless link with the device of the next transfer destination specified based on the first route identification information, or a route having a low wireless usage rate on the wireless link to the destination. Is executed to ensure that the data is transferred by another route, such as when is present. The route information changing unit 305 may arbitrarily add route identification information indicating a usable route. Further, when the route information changing unit 305 adds the second route identification information to the received signal, the route information changing unit 305 deletes the first route identification information from the received signal. For example, when the route specified by the first route identification information is not available, the first route identification information is deleted.

The setting acquisition unit 306 obtains setting information indicating whether or not the addition or deletion of the route identification information is permitted, and setting information for determining whether or not the route identification information can be added or deleted from, for example, the base station apparatus 101. get. It should be noted that these settings may be made for each route, or may be made comprehensively for a plurality of or all routes. These setting information are notified before the communication of the signal including the data is performed. The relay device determines whether or not the route identification information can be added / deleted based on the setting information acquired by the setting acquisition unit 306. Then, the route information changing unit 305 executes addition / deletion of the route identification information based on the result of this determination. When the route identification information is added / deleted, the change notification unit 307 notifies the base station apparatus 101 that the addition / change has occurred.

(Processing flow)
The flow of processing executed by the relay device will be outlined with reference to FIG. The process of FIG. 4 is executed, for example, by a relay device (that is, a relay device that is not at the end of the route) existing in the middle of the route between the relay device directly connected to the terminal device and the base station device. In this process, the relay device first acquires the setting information from the base station device 101 (S401). The relay device determines whether or not the addition / deletion of the route identification information in the subsequent processing is permitted based on the acquired setting information. Note that this process does not have to be executed, for example, when the relay device is always allowed to add / delete the route identification information, or when the setting is completed when the relay device is installed. ..

The relay device receives a signal from another device (for example, a base station device or another relay device) (S402). The relay device analyzes the received signal, extracts the destination information indicating the destination device included in the signal and the route identification information indicating the route, and identifies the route to which the signal should be transferred based on the route identification information. (S403). Then, the relay device determines the transfer destination device based on the specified route (S404).

For example, the relay device determines the device to which the signal should be transferred next to the own device in the route specified in S403 as the transfer destination device. At this time, the relay device may determine that communication with the transfer destination device should not be performed, for example, when a failure occurs in the wireless link with the next transfer destination device on the route. It is possible. In this case, the relay device may determine another device not included in the path as the signal transfer destination. At this time, the relay device adds, for example, route identification information indicating a route including the device determined as the transfer destination of this signal (S405). Further, the relay device may add route identification information of the route, for example, when there is a route having a low wireless usage rate of the wireless link in the route between the own device and the destination device. Further, when adding the route identification information, the relay device may delete the route identification information included in the received signal. When the setting information is acquired in S401, the addition / deletion of the route identification information is executed according to the setting information. The addition / deletion of the route identification information may not be performed if the route to be added does not exist. That is, the route identification information included in the received signal may be maintained as it is. When the relay device adds / deletes the route identification information in S405, the relay device notifies the base station device 101 to that effect (S406). Note that this notification does not have to be given.

After that, the relay device transfers the data included in the signal received in S402, the destination information included in the received signal, and the signal including the route identification information set in S405 to the transfer destination device determined in S404. Transmit (S407).

As described above, according to the relay device as described above, in a situation where it is difficult to transfer the signal along the route based on the identification information of the route included in the signal, the signal deviates from the route. By continuing the transfer, the signal can be transferred to the destination device. Further, at that time, by adding the route identification information indicating the route as described above, it is easy to determine the transfer destination of the signal in the transfer destination device, or the degree of freedom in selecting the transfer destination in the device is increased. Can be improved.

The present invention is not limited to the above embodiments, and various modifications and modifications can be made without departing from the spirit and scope of the present invention. Therefore, in order to make the scope of the present invention public, the following claims are attached.

Claims (14)

A relay device that relays communication between a base station device and a terminal device.
A receiving means for receiving a signal transmitted for the communication from another device, and
Based on the first identification information included in the received signal, which indicates a route to which the data included in the received signal is transferred between the base station device and the terminal device. A determination means for determining the device to which the data is transferred, and
A second identification to which the data is transferred, which is a signal containing the data and indicates a route different from the route indicated by the first identification information in the received signal to the determined transfer destination device. A means of transmitting a signal with added information, and
A relay device characterized by having. The determination means determines a specific device as the transfer destination device when the route indicated by the first identification information cannot be used.
The transmitting means transmits a signal obtained by adding the second identification information indicating a route including the specific device to the received signal.
The relay device according to claim 1, wherein the relay device is characterized by the above. The relay device according to claim 1 or 2, wherein the second identification information indicates a route via the relay device. Further having a means for acquiring information indicating whether or not the addition of the second identification information is permitted from the base station apparatus.
The transmitting means adds the second identification information to the signal when the addition of the second identification information is permitted.
The relay device according to any one of claims 1 to 3, wherein the relay device is characterized by the above. The relay device according to any one of claims 1 to 4, further comprising means for notifying the base station device that the second identification information has been added to the received signal. Further having a means for acquiring information for determining whether or not one or more routes can be added from the base station apparatus.
The transmission means adds the second identification information corresponding to the route specified based on the information for determining whether or not addition is possible to the reception signal and transmits the second identification information to the transfer destination device.
The relay device according to any one of claims 1 to 5, characterized in that. The relay device according to claim 6, wherein the information for determining whether or not to add is information on the radio usage rate in each of the one or more routes. Claim 1 is characterized in that, when the second identification information is added, the transmission means transmits a signal obtained by deleting the first identification information from the received signal to the transfer destination device. 7. The relay device according to any one of 7. Further having a means for acquiring information indicating whether or not the deletion of the first identification information is permitted from the base station apparatus.
The transmitting means deletes the first identification information from the received signal when the deletion of the first identification information is permitted.
The relay device according to claim 8, wherein the relay device is characterized by the above. The relay device according to claim 8 or 9, further comprising means for notifying the base station device that the first identification information has been deleted from the received signal. Further having a means for acquiring information for determining whether or not to delete one or more routes from the base station device,
When the transmission means determines that the first identification information should be deleted based on the information for determining whether or not the deletion is possible, the transmission means deletes the first identification information from the reception signal to the transfer destination. Send to device,
The relay device according to any one of claims 8 to 10, characterized in that. The second identification information includes information that identifies a line used for transferring the data between devices included in the route specified by the second identification information.
The relay device according to any one of claims 1 to 11, characterized in that. A control method executed by a relay device that relays communication between a base station device and a terminal device.
Receiving the signal transmitted for the communication from another device and
Based on the first identification information included in the received signal, which indicates a route to which the data included in the received signal is transferred between the base station device and the terminal device. Determining the device to which the data is transferred
A second identification indicating a route to which the data is transferred, which is a signal containing the data to the determined transfer destination device and is different from the route indicated by the first identification information in the received signal. Sending a signal with added information and
A control method characterized by including. To the computer installed in the relay device that relays the communication between the base station device and the terminal device,
The signal transmitted for the communication is received from another device, and the signal is received from another device.
Based on the first identification information included in the received signal, which indicates a route to which the data included in the received signal is transferred between the base station device and the terminal device. The device to which the data is transferred is determined.
A second identification to which the data is transferred, which is a signal containing the data and indicates a route different from the route indicated by the first identification information in the received signal to the determined transfer destination device. Send a signal with added information,
Program for.

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