JP7509836B2 - COMMUNICATION DEVICE, CONTROL METHOD, AND PROGRAM FOR ENABLED EFFICIENT OPERATION OF RELAY TRANSMISSION SYSTEM - Google Patents

Description

The present invention relates to technology for the efficient operation of relay transmission systems.

In a cellular communication system, a technique for relaying communication between a base station device and a terminal device is known. For example, Patent Document 1 describes a relay transmission system using Integrated Access and Backhaul (IAB). A mesh network is also known as a form of relay transmission. In a mesh network, if a failure occurs in one of the links in a set communication path, a different communication path that does not pass through that link is set, allowing communication to continue.

JP 2022-107426 A

In a relay transmission system using IAB, it is necessary to demodulate the routing information between relay devices at the media access control (MAC) layer (layer 2). This demodulation causes a certain processing delay, and it is assumed that, for example, control such as rapid route switching cannot be performed. In addition, since the cost of the device related to the function for the demodulation process of layer 2 is required, the cost of preparing a large number of relay devices and constructing a network may increase. In contrast, by configuring a mesh network using repeaters that relay at the physical layer (layer 1), there is no processing delay related to the demodulation process of layer 2, and the network configuration cost can be reduced. However, since a routing protocol is not implemented in layer 1, it is not possible to set up advanced routes, and it may take a lot of time to process such as route switching.

The present invention provides technology that enables advanced and efficient control of mesh networks involving layer 1 relay transmission.

A communication device according to one embodiment of the present invention has a relay means for relaying a radio signal sent from a base station device as a physical layer radio repeater , and a communication means for communicating with other devices that relay the radio signal sent from the base station device, wherein the communication means receives first information from the first other device indicating a first route along which the radio signal reaches from the base station device to a first other device and indicating that radio waves will be sent, the relay means detects the radio waves output from the first other device based on the first information, and when the communication means is able to detect the radio waves output from the first other device, it notifies the first other device of second information indicating a second route which adds a section from the first other device to the communication device to the first route, and the relay means relays the radio signal sent from the base station device and received from the first other device according to the second route.

The present invention enables advanced and efficient control of mesh networks involving layer 1 relay transmission.

FIG. 1 is a diagram illustrating an example of the configuration of a wireless communication network. FIG. 2 is a diagram illustrating a state in which a communication device receives a signal from another communication device. FIG. 1 is a diagram outlining a procedure for identifying a relay transmission path. 11A and 11B are diagrams illustrating an example of timing for receiving radio waves in each communication device. FIG. 2 illustrates an example of a hardware configuration of the apparatus. FIG. 2 is a diagram illustrating an example of a functional configuration of a control device. FIG. 2 illustrates an example of a functional configuration of a communication device. FIG. 1 is a diagram showing an example of a flow of processing executed in a wireless communication network. FIG. 1 is a diagram outlining a procedure for identifying a relay transmission path. FIG. 2 illustrates an example of a functional configuration of a communication device. FIG. 1 is a diagram showing an example of a flow of processing executed in a wireless communication network.

The following embodiments are described in detail with reference to the attached drawings. Note that the following embodiments do not limit the invention according to the claims, and not all combinations of features described in the embodiments are necessarily essential to the invention. Two or more of the features described in the embodiments may be combined in any combination. In addition, the same reference numbers are used for the same or similar configurations, and duplicate descriptions are omitted.

<Embodiment 1>
(System configuration)
FIG. 1 shows an example of the configuration of a wireless communication system according to this embodiment. The wireless communication system is a wireless mesh network, and in one example, includes a base station device 101 and multiple communication devices (communication devices 111 to 116). The base station device 101 is, for example, a base station device that performs wireless communication in accordance with a fifth generation (5G) cellular communication standard, and is configured to establish a connection with a terminal device to perform wireless communication. The communication devices 111 to 116 can be, for example, communication devices that can establish a connection with a terminal device and perform wireless communication, similar to a base station device. However, in this embodiment, the communication devices 111 to 116 have a function of relaying a signal transmitted from the base station device 101 at the physical layer (layer 1) like a repeater. In addition, the communication devices 111 to 116 can be configured as a single device that has, for example, a function as a layer 1 repeater and a function for communicating with other communication devices and a control device 121 described later, but are not limited to this. For example, the communication devices 111 to 116 may be realized as a collection of devices in which these functions are implemented as separate devices. It is assumed that signals are transmitted between the base station device 101 and each of the communication devices 111 to 116 using a frequency band capable of large-capacity communication, such as millimeter waves, and a backhaul line is constructed by wireless communication. Radio waves in a frequency band for the backhaul line sent from the base station device 101 are amplified and output by a communication device (for example, the communication device 111) that receives the radio waves. The amplified and output radio waves are further received by another communication device, which then amplifies and outputs the radio waves. In this way, a relay transmission path is established via multiple communication devices.

When a communication device receives a signal addressed to a terminal device under its control, it demodulates the signal, converts it into a signal format that the terminal device can receive, and transmits it to the terminal device. The communication device also converts the signal received from the terminal device into a format that can be transmitted over a backhaul line, and transmits it to another communication device or a base station device. Note that this is just one example, and the communication device may also have a function as a general repeater. That is, the communication device has a function to amplify and output radio waves arriving from a base station device, a terminal device, or another communication device (repeater), but may not have a function such as a process of converting a signal received from a base station device or another communication device into a wireless signal format that the terminal device can process, or a process of converting a signal received from a terminal device into a format for sending to a backhaul line. Note that the following description focuses on the relay communication function in the communication device.

In general, in a communication system using a repeater that relays at layer 1, the repeater is arranged at a pre-planned position, and the repeater simply amplifies and outputs the radio waves it receives, thereby improving the coverage area. In such a configuration, the repeater only emits radio waves in a pre-set direction, and it is not easy to perform flexible communication such as switching relay routes in a mesh network. On the other hand, in recent years, there are repeaters that are configured to be able to set beams in multiple patterns and can relay using beams of any of these patterns. In such a repeater, for example, by using a beam of a pattern that can detect a signal with the maximum received power, it is possible to selectively use a relay route with good wireless quality. However, setting such a relay route requires a lot of time, and flexible route switching, such as using other links after the wireless quality of some links has deteriorated, cannot be performed quickly. In addition, when control based on upper layers such as layer 2 or higher is performed, flexible route switching control can be performed, but it is necessary to perform decoding processing of layer 2 or higher, and it still takes a certain amount of time to switch routes.

In this embodiment, in consideration of such circumstances, a method is provided for easily switching relay paths at layer 1. For example, the control device 121 identifies the relationship of the order of relay transmission formed by each communication device based on the position information of each communication device, the direction of the beam when receiving radio waves, and the reception timing information. Then, the control device 121 forms routing information for forming a relay transmission path. The control device 121 can form setting information for relay processing in each communication device for forming a relay transmission path as routing information. Then, the control device 121 can notify each communication device of the formed routing information. Note that each communication device may communicate with the control device 121 using, for example, a wired communication line, or may communicate with the control device 121 via, for example, the base station device 101. The communication device may also be capable of wireless communication using legacy communication methods such as Long Term Evolution (LTE), a fifth generation (5G) cellular communication system, wireless LAN, and Bluetooth (registered trademark) Low Energy (BLE), and may perform control communication with the control device 121 via such wireless communication.

For example, the communication device performs a detection process of a wireless signal using multiple beam patterns that can be used to receive a signal. The communication device selects a beam in which a wireless signal is received with the strongest power or with a power equal to or greater than a predetermined value, and notifies the control device 121 of information indicating the beam. For example, in the example of FIG. 2, the communication device 202 measures a wireless signal transmitted from a base station device or the communication device 201 with each pattern of beams 211 to 215. Then, the communication device 202 notifies the control device 121 of, for example, the position of the device itself and information on the direction of beam 212. In this case, the communication device 201 may form multiple beams when outputting a wireless signal, and may be configured to amplify the received wireless signal and output it from at least a part (all in one example) of the multiple beams. Then, the communication device 202 detects a wireless signal sent from one or more of the beams. In addition, the communication device 201 may be capable of forming only one beam, and in that case, is configured to output the amplified wireless signal using that beam.

The information on the direction of orientation may include, for example, the attitude (antenna arrangement) and antenna weight information of the communication device 202. In this case, the control device 121 may identify the antenna pattern from the antenna weight information, and identify the direction of orientation information of the communication device 202 based on the pattern and the attitude information. Note that this is merely an example, and the communication device 202 itself may identify the direction of orientation from its own antenna weight and antenna pattern, and notify the control device 121 of the identified information. The communication device 202 may also notify the control device 121 of information indicating which of a plurality of fixed directional antennas has detected a wireless signal with sufficient power.

The control device 121 may have information on the relationship between each antenna pattern and its directional direction and the corresponding index in advance. In this case, the communication device 202 may notify the control device 121 of index information indicating which antenna pattern detected the wireless signal with sufficient power. This allows the control device 121 to identify the antenna pattern corresponding to the index and to identify the direction in which the communication device 202 detected the incoming radio wave with sufficient power. The communication device 202 may notify the control device 121 of information indicating the antenna pattern and information indicating an index that can identify the antenna pattern, for example, when installed. Also, for example, such information may be input by the communication carrier to the communication device 202 and the control device 121 before the operation of the communication device 202 is actually started. Furthermore, when the communication device is installed, the location information of the communication device may be input to the control device 121. In this case, the control device 121 may acquire only information that can identify which antenna pattern was used to detect the wireless signal with sufficient power in each communication device.

When the control device 121 acquires the position of the communication device and the direction of reception of the radio wave from each communication device, it identifies the node that output the radio wave received by that communication device. For example, as shown in FIG. 3, the control device 121 identifies a base station device or other communication device that exists in the direction corresponding to the beam 212 from the position of the communication device 202 based on the information received from the communication device 202. The control device 121 acquires, for example, position information and information on the direction of the beam used when detecting the radio signal for the communication device 201 and the communication device 203. The control device 121 also holds, for example, information on the position of the base station device 101. Here, the candidates for the source of the radio signal received by the communication device 202 are devices other than the communication device 202. For this reason, the control device 121 determines whether the position of the base station device 101, the position of the communication device 201, and the position of the communication device 203 exist in the direction corresponding to the beam 212 based on the position of the communication device 202. As a result, the control device 121 identifies, for example, that the source of the radio signal detected in the communication device 202 is the communication device 201. Similarly, the control device 121 can determine that the source of the wireless signal detected by the communication device 201 is the base station device 101. From these determination results, the control device 121 can determine that there is a relay transmission path through which the wireless signal is relayed in the order of the base station device 101, the communication device 201, and the communication device 202.

In the same manner, the control device 121 identifies all available relay transmission paths. For example, in the example of FIG. 1, three paths may be identified as paths from the base station device 101 to the communication device 116: (1) a path via the base station device 101, the communication device 111, the communication device 114, and the communication device 115; (2) a path via the base station device 101, the communication device 111, the communication device 112, and the communication device 115; and (3) a path via the base station device 101, the communication device 111, the communication device 112, and the communication device 113.

In order to switch between the paths (1) to (3), it is necessary that the signal transmitted from the base station device 101 is relayed on those paths, and that the beam used to transmit the signal is the same. That is, when switching to a path where a signal transmitted from a base station device other than the base station device 101 is relayed, or a path where a signal transmitted from a different beam in the base station device 101 is relayed, control is required in the base station device 101 or the core network for the switching, and the path cannot be switched quickly. For this reason, each communication device may specify a beam ID indicating which beam the signal transmitted from the base station device 101 was transmitted by, and notify the control device 121 of the beam ID. Each communication device amplifies and outputs the received radio signal without at least changing the beam ID. In addition, when each communication device is located in a position where it does not receive signals from base stations other than the base station device 101, and the base station device 101 forms only one beam, each communication device does not need to notify the beam ID.

In addition, the control device 121 may specify the relay transmission path based on the arrival timing of the radio signal in addition to or instead of the positional relationship in each communication device and the pattern of the beam that detected the signal. For example, the control device 121 collects the timing at which the radio signal was detected in each communication device. In one example, the control device 121 may collect the value of the timing advance set in each communication device. For example, when the value of the timing advance in the communication device 111 is T1, it can be determined that the signal transmitted from the base station device is received with a delay of half the time (T1/2) of T1. Similarly, when the value of the timing advance in the communication device 112 is T2, it can be determined that the signal transmitted from the base station device is received with a delay of a time (T2/2). In addition, each communication device may record the time at which the radio signal was detected using, for example, a global positioning system (GPS) or a standard radio wave, and notify the control device 121. Here, the difference between the detection timing of the signal and the timing at which the frame was transmitted is specified. For example, when the detection time of a wireless signal is determined at an individual timing in each communication device, the difference between the timing at which the wireless signal with the frame number determined based on the frame number of the wireless signal is sent and the detection time is determined. In other words, here, the time difference until the wireless signal sent from the base station device 101 is detected in each communication device is determined.

The control device 121, for example, determines the time difference between the timing at which a radio signal is sent by the base station device 101 in FIG. 1 and the timing at which the radio signal is detected by the communication devices 111 to 116, as shown in FIG. 4. In this case, the control device 121 determines that the radio signal arrived in the following order: base station device 101, communication device 111, communication device 112 and communication device 114, communication device 113 and communication device 115, and communication device 116. The control device 121 can roughly determine the relay transmission path based on the order in which the radio signal arrives. Here, the control device 121 can, for example, store the positional relationship of the communication devices in advance or obtain it from each communication device, and determine the detailed relay transmission path based on the positional relationship and the arrival timing of the radio signal. The control device 121 may determine that a relay transmission section is formed between the communication device 111 and the communication device 112, for example, in response to the correspondence between the time when the radio wave propagates through the distance between the communication device 111 and the communication device 112 and the arrival time difference of the radio signal. The control device 121 may also determine that the time when the radio wave propagates through the distance between the base station device 101 and the communication device 112 does not correspond to the time difference between the transmission timing of the radio signal at the base station device 101 and the arrival timing of the radio signal at the communication device 112. As a result, the control device 121 may determine that there is no section where the radio wave directly arrives between the base station device 101 and the communication device 112. In this way, the control device 121 can specify the section where the radio wave propagates in the relay transmission based on the arrival timing of the radio signal at each communication device, and specify the relay transmission path. Note that the control device 121 may, for example, recognize the beams that each communication device can use in advance, and in that case, it can specify the beam to be used in the relay transmission path. Note that, for example, if each communication device can only form a single beam pattern, the beam does not need to be specified.

In one example, the above-mentioned processing may be performed while the communication service is being provided by the base station device 101. That is, it is not necessary to prepare a dedicated period for identifying the relay transmission path as described above. For example, each communication device acquires a radio signal using an antenna pattern that receives the radio signal strongest or at a predetermined power or higher, and amplifies and outputs the radio signal. The antenna pattern and the reception timing of the radio signal are identified and provided to the control device 121. In addition, a dedicated period for identifying the relay transmission path may be set, for example, during a time period with low data traffic. This allows the relay transmission path to be identified with high accuracy. Note that the control device 121 notifies each communication device of information indicating the dedicated period, and each communication device may execute processing for identifying the relay transmission path during the dedicated period.

In the above process, the control device 121 has been described as specifying a relay transmission path based on a receiving beam pattern that detects a wireless signal with sufficient power in each communication device. Instead of or in addition to this receiving beam pattern, a transmitting beam pattern may be used when specifying a relay transmission path. For example, the communication device may output radio waves while switching the transmitting beam pattern in a time-division manner during a dedicated period for specifying the relay transmission path, and the other communication device may detect the radio waves. The other communication device may specify the timing at which the radio waves were detected strongest or at a predetermined power or higher, and notify the control device 121 of the information on the timing. In one example, each communication device may notify the control device 121 of the correspondence between the transmitting beam pattern and the time interval, so that the control device 121 can specify the transmitting beam pattern according to the detection timing of the radio waves in the other communication device. Also, each communication device may, for example, notify the control device 121 of a usable transmitting beam pattern, and the control device 121 may generate information specifying the time interval in which each of the transmitting beam patterns is used, and notify each communication device. This allows the control device 121 to identify the transmitting side beam pattern to be used in the relay transmission. As a result, the control device 121 can identify a relay transmission path that takes into account the transmitting side beam pattern available in the communication device, in the same way as in the case of the receiving side beam pattern described above.

The control device 121 notifies each communication device of the relay transmission path information identified as described above as routing information. In one example, the control device 121 notifies each communication device of information that can identify the relay transmission path in which the communication device is involved. For example, in the system of FIG. 1, the communication device 115 is notified of (1) the relay transmission path consisting of the base station device 101, the communication device 111, the communication device 114, and the communication device 115, and (2) the relay transmission path consisting of the base station device 101, the communication device 111, the communication device 112, and the communication device 115, as information on the path from the base station device 101 to the communication device 115. In addition, as communication paths involving the communication device 115, (3) a relay transmission path consisting of the base station device 101, the communication device 111, the communication device 114, the communication device 115, and the communication device 116, which is a communication path between the base station device 101 and the communication device 116, and (4) a relay transmission path consisting of the base station device 101, the communication device 111, the communication device 112, the communication device 115, and the communication device 116 are notified to the communication device 115. When the control device 121 or the base station device 101 instructs that the path from the base station device 101 to the communication device 115 should be used, for example, each communication device can operate to use either the path (1) or (2) described above. When the path from base station device 101 to communication device 116 should be used, in addition to the above (3) and (4), (5) each communication device can operate to use one of the relay transmission paths consisting of base station device 101, communication device 111, communication device 112, communication device 113, and communication device 116.

The control device 121 may also notify one or more beam patterns to be used by each of the communication devices as information on the routing information. For example, the control device 121 may notify the communication device 115 that a beam directed toward the communication device 114 should be used in the route (1), and a beam directed toward the communication device 112 should be used in the route (2). Note that the information indicating the above-mentioned route may not be notified, and only information on a beam capable of relaying a radio signal sent from the base station device 101 may be notified. The control device 121 may also include, as information on the routing information, a beam pattern to be used by each communication device when outputting a signal. That is, the control device 121 may, for example, identify a beam pattern for transmission or reception of each communication device to be used to form each relay transmission path, and provide information on the beam pattern to each communication device. Note that information on beam patterns corresponding to multiple relay transmission paths may be provided to the communication device. In this case, priority information indicating which relay transmission path (beam pattern) should be used preferentially may be provided to each communication device. The priority order may be determined according to, for example, the wireless quality or the number of hops to the base station device 101. For this reason, when each communication device notifies the control device 121 of information on the wireless quality of the wireless signal when it detects a wireless signal with a predetermined power or more, the communication device may further notify the control device 121 of information on the wireless quality of the wireless signal. The information on the wireless quality may be, for example, the reference signal received power (RSRP), the reference signal received quality (RSRQ), the signal-to-noise ratio (SNR), or the like. The control device 121 may determine the priority order of the relay transmission path so that, for example, the better the minimum value of the wireless quality on the relay transmission path, the higher the priority order. Note that this is only an example, and the priority order may be determined based on, for example, the average value or maximum value of the wireless quality. The communication device performs relay transmission using, for example, the beam pattern with the highest priority order among the notified multiple relay transmission paths. Then, when the communication device detects the occurrence of a failure due to the fact that the wireless signal has not been received for a predetermined period of time on the path in use, the communication device may switch the beam pattern to be used to the beam pattern with the next highest priority order and perform relay transmission. With this, the communication device can switch the beam pattern depending on the communication situation, which results in the relay transmission path being switched quickly. As a result, the period during which communication is interrupted due to a failure or the like can be shortened.

In addition, when the communication device detects the occurrence of a failure, the communication device may notify the control device 121 that the failure has occurred. In this case, the control device 121 may instruct each communication device to switch the relay transmission path. This allows the control device 121 to identify where the failure has occurred in the relay transmission path and to appropriately switch the relay transmission path based on the identified result. For example, in the example of FIG. 1, it is assumed that a relay transmission path including the base station device 101, the communication device 111, the communication device 114, the communication device 115, and the communication device 116 is used. Here, if a failure occurs in the section between the communication device 114 and the communication device 115, the communication device 115 detects the occurrence of a failure, for example, by the fact that a signal from the communication device 114 does not reach. At this time, as a result of the signal not reaching the communication device 115, the signal also does not reach the communication device 116, and the communication device 116 may also determine that a failure has occurred. In such a case, when each communication device autonomously switches the relay transmission path, for example, the communication device 115 switches the beam pattern to use a path including the base station device 101, the communication device 111, and the communication device 112, while the communication device 116 may also switch the beam pattern to use a path including the base station device 101, the communication device 111, the communication device 112, and the communication device 113. At this time, it may be assumed that the communication device 113 is not involved in any of the relay transmission paths in use and has its power turned off as described below. In this case, since the communication device 113 does not relay the radio waves sent from the communication device 112, the communication device 116 may still be unable to detect the radio waves even after switching the beam pattern, and the situation in which communication is not possible may continue. In contrast, as described above, the communication device 115 and the communication device 116 notify the control device 121 of the occurrence of a failure, and the communication device 121 may determine that no failure has occurred between the communication device 115 and the communication device 116. The control device 121 can then control the switching of the relay transmission path, for example, to cause the communication device 115 to change the beam pattern while preventing the communication device 116 from changing the beam pattern.

Each communication device may also monitor whether the failure has been resolved in the communication path where the failure occurred. For example, in the above-mentioned situation, communication device 115 may monitor whether radio waves from communication device 114 arrive while directing a beam in the direction of communication device 112. Then, each communication device may determine that it has recovered from the failure, for example, by detecting normal radio waves or detecting radio waves with better wireless quality than those received by the beam currently in use. Then, each communication device may autonomously switch the beam pattern so as to use the original relay transmission path upon recovery from the failure. Furthermore, each communication device may notify control device 121 of recovery from the failure when the failure is resolved. In this case, control device 121 may instruct each communication device to return the relay transmission path to the original path based on the notification.

In order to prepare information on a plurality of relay transmission paths, it is important that the plurality of relay transmission paths are paths for transferring the same signal sent from the base station device 101. For example, if the base station device 101 can form a plurality of beams, different information can be sent from each of the plurality of beams. For this reason, in order to form a plurality of paths for transferring the same signal sent from the base station device 101, each communication device may notify the control device 121, for example, of the beam ID of the detected wireless signal or the identification information (SSB ID) of the synchronization signal/physical broadcast signal block (SSB). Then, the control device 121 may set separate relay transmission paths for signals sent by different beams, for example, and notify each communication device of the information. When such a notification is made, the communication device identifies which of the plurality of beams that the base station device 101 can form from which the wireless signal has arrived, for example by checking the header of the physical layer of the wireless signal. Then, the communication device may relay using the beam to be used in the device itself, which has been notified in correspondence with the relay transmission path for transmitting the wireless signal sent by the identified beam.

The control device 121 may also instruct the communication devices belonging to the unused relay transmission path to turn off at least the power supply of the communication circuit, etc. corresponding to that path. For example, in the example of FIG. 1, when the path in which the radio waves reach the communication device 115 from the communication device 112 is not used, the power supply of the circuit in the communication device 112 that outputs the radio waves in the direction of the communication device 115 may be turned off, and the power supply of the circuit in the communication device 115 that receives the radio waves from the direction of the communication device 112 may be turned off. Also, when the relay transmission path passing through the communication device 113 is not used, for example, the control device 121 may instruct to turn off the entire communication device 113. In this case, the communication device 113 may turn on only the circuit that receives the radio waves from the direction of the communication device 112, for example. When the communication device 113 receives the radio waves from the direction of the communication device 112, for example, the communication device 113 may determine that the communication device 112 has output the radio waves in the direction of the communication device 113 because the relay transmission path from the communication device 112 to the communication device 115 through the communication device 115 to the communication device 116 cannot be used. In this case, communication device 113 may start outputting radio waves in the direction of communication device 116. In this way, in this embodiment, it is possible to quickly switch and use relay transmission paths while suppressing power consumption by turning off communication functions that are not being used.

(Device configuration)
A hardware configuration example of the control device and the communication device will be described with reference to FIG. 5. In one example, the control device and the communication device are configured to include a processor 501, a ROM 502, a RAM 503, a storage device 504, and a communication circuit 505. The processor 501 is a computer configured to include one or more processing circuits such as a general-purpose CPU (Central Processing Unit) or an ASIC (Application Specific Integrated Circuit), and executes the overall processing of the device and each of the above-mentioned processes by reading and executing a program stored in the ROM 502 or the storage device 504. The ROM 502 is a read-only memory that stores information such as programs and various parameters related to the processing executed by the control device and the communication device. The RAM 503 functions as a workspace when the processor 501 executes a program, and is a random access memory that stores temporary information. The storage device 504 is, for example, configured by a removable external storage device.

The communication circuit 505 of the communication device has a function of amplifying and outputting a radio signal transmitted by, for example, a base station device or another communication device. The communication circuit 505 of the communication device can be configured to form an antenna weight for at least one of signal transmission and reception, for example, by setting an antenna weight corresponding to each of a plurality of antennas. The communication circuit 505 of the communication device can also be configured to be connected to, for example, a plurality of directional antennas and to use at least one of them. Furthermore, the communication circuit 505 of the communication device can be prepared separately for each of a plurality of beam patterns, and the communication circuit 505 corresponding to a beam pattern other than the beam pattern to be used can be configured to be turned off. The communication circuit 505 of the communication device can also have a communication function for notifying the control device of information capable of identifying the beam pattern that detected the radio signal strongest or with a predetermined power or more, information capable of identifying the time difference between when the radio signal is sent and when it is received, and position information of the communication device. In one example, the communication circuit 505 of the communication device can be configured to notify the base station device of the information via, for example, a relay transmission path. In this case, the base station device can transfer the information to the control device. The communication circuit 505 of the communication device may also have a function of directly notifying the control device of the information using a legacy communication method or a wired communication method. The communication circuit 505 of the communication device may also be configured to receive information on the routing information generated by the control device, for example, via a relay transmission path or directly from the control device.

The communication circuit 505 of the control device may have any communication function capable of acquiring information from a communication device and transmitting information to the communication device. The communication circuit 505 of the control device may be configured to establish a connection with a base station device or a communication device using a wired communication method, for example, to transmit and receive information. The communication circuit 505 of the control device may also be configured to be capable of communicating using a legacy communication method, for example, and to perform wireless communication with the communication device using that communication method.

Figure 6 is a diagram showing an example of the functional configuration of the control device. The control device has, for example, an information acquisition unit 601, a transmission path identification unit 602, and a routing information notification unit 603 as its functions. Note that the functional blocks in Figure 6 are shown in schematic form, and each functional block may be integrated and realized, or may be further subdivided. Also, each function in Figure 6 may be realized, for example, by the processor 501 executing a program stored in the ROM 502 or the storage device 504, or may be realized, for example, by a processor present inside the communication circuit 505 executing a predetermined software. Note that the details of the processing performed by each functional unit will not be described in detail here, and only the general functions will be outlined.

The information acquisition unit 601 acquires at least one of information capable of identifying the beam pattern of the communication device that received the radio signal strongest or with a predetermined power or higher, location information of the communication device, and information capable of identifying the time difference between when the radio signal is transmitted from the base station device and when the communication device detects the radio signal. Based on the information acquired by the information acquisition unit 601, the transmission path identification unit 602 identifies which device each communication device will amplify and output the signal from, for example, as described above, and identifies the relay transmission path. The routing information notification unit 603 notifies each communication device of the beam pattern to be used to form the relay transmission path identified by the transmission path identification unit 602. The routing information notification unit 603 may also instruct the communication device to, for example, turn off the communication function in the beam pattern corresponding to the relay transmission path that is not used.

Figure 7 is a diagram showing an example of the functional configuration of a communication device. The communication device has, for example, a measurement unit 701, an information notification unit 702, and a routing control unit 703 as its functions. Note that the functional blocks in Figure 7 are shown in schematic form, and each functional block may be integrated and realized, or may be further subdivided. Also, each function in Figure 7 may be realized, for example, by the processor 501 executing a program stored in the ROM 502 or the storage device 504, or may be realized, for example, by a processor present inside the communication circuit 505 executing a predetermined software. Note that the details of the processing performed by each functional unit will not be described in detail here, and only the general functions will be outlined.

The measurement unit 701 receives a radio signal arriving from another communication device or a base station device, for example, using each of a plurality of beam patterns, and identifies which beam pattern is used to detect the radio signal strongest or at a predetermined power or higher. The measurement unit 701 also identifies, for example, the timing at which the radio signal arriving from the other communication device or the base station device is detected. The measurement unit 701 may also identify, for example, the time difference between the identified timing and the timing at which the radio signal is transmitted by the base station device. The measurement unit 701 may also identify this time difference from the value of the timing advance. Also, for example, when the other communication device outputs a radio signal by switching between a plurality of transmission beam patterns, the measurement unit 701 may measure the radio signal using one reception beam pattern and identify the timing at which the radio signal was detected strongest or at a predetermined power or higher. Then, the measurement unit 701 may identify the transmission beam pattern used to transmit the radio signal detected strongest or at a predetermined power or higher based on the timing.

The information notification unit 702 notifies the control device of the beam pattern information identified by the measurement unit 701 and the above-mentioned time difference information. The information notification unit 702 may, for example, notify the control device of an index previously assigned to the beam pattern as information on the beam pattern for reception. The information notification unit 702 may also notify the control device of information for identifying which frame was received at what timing (for example, a frame number and a reception timing) instead of the time difference information. The information notification unit 702 may also notify the control device of information on the timing at which the radio signal was detected strongest or at a predetermined power or higher during a period in which the radio signal was output by switching between multiple transmission beam patterns, without identifying the transmission beam pattern of another base station device. In this case, the control device may identify the transmission beam pattern corresponding to that timing.

The routing control unit 703 acquires from the control device routing information determined by the control device based on the information notified by the information notification unit 702, and sets the beam pattern for reception and the beam pattern for transmission to be used for communication based on the information. The routing control unit 703 may acquire multiple pieces of routing information, each of which has a priority. In this case, the routing control unit 703 uses the routing information with the highest priority to set the relay. In addition, the routing control unit 703 sets the relay transmission path using the routing information with the next highest priority when, for example, the wireless quality in the communication using the setting in use has deteriorated. In addition, information on the beam pattern for transmission to be used in each communication device may be included in the header of the physical layer in the wireless signal, and the routing control unit 703 may set the antenna pattern to be used for each wireless signal based on the information. In addition, information indicating which communication device the wireless signal should be transferred to may be included in the header of the physical layer of the wireless signal. In this case, for example, when the routing control unit 703 receives a wireless signal including information indicating that the signal should be transferred to its own device, the routing control unit 703 may set the wireless signal not to be relayed.

(Processing flow)
FIG. 8 shows an example of the flow of processing executed in this embodiment. First, each communication device measures the radio signal sent by the base station device, for example, using a plurality of beam patterns for reception. Here, it is assumed that the radio signal sent by the base station device is detected in the communication device A (S801), and the radio signal is not detected in the communication devices B and C. Then, it is assumed that the communication device A amplifies the radio signal received from the base station device, outputs the radio signal using one or more beam patterns for transmission, and the communication devices B and C detect the radio signal (S802, S803). Also, it is assumed that the communication device B amplifies the radio signal received from the communication device A, outputs the radio signal using one or more beam patterns for transmission, and the communication device C detects the radio signal (S804). Then, the communication devices A to C notify the control device of information that can identify the beam pattern for reception when the radio signal is detected strongest or with a predetermined power or more, information on the detection timing of the radio signal, etc. (S805 to S807). The control device identifies a communication path from the base station device to each communication device based on the received information (S808). At this time, the control device can identify, for example, a plurality of communication paths to each communication device.

Then, the control device notifies each communication device of routing information including information on beam patterns for forming the multiple communication paths (S809 to S811). Here, it is assumed that the control device notifies the routing information so as to set the relay transmission path in which the wireless signal is relayed in the order of the base station device, communication device A, and communication device C as the highest priority path. Based on this routing information, the communication device A sets, for example, a receiving beam pattern that can receive the wireless signal from the base station device strongest or at a predetermined power or higher. Based on this routing information, the communication device A can also set, for example, a transmitting beam pattern corresponding to the timing when the wireless signal from the communication device A can be received strongest or at a predetermined power or higher in the communication device C. Based on this routing information, the communication device C sets, for example, a receiving beam pattern that can receive the wireless signal from the communication device A strongest or at a predetermined power or higher. Here, since the communication device B is not involved in this relay transmission path, in one example, the control device may instruct the communication device B to turn off the communication circuit. In this case, communication device B can reduce power consumption by, for example, turning off the power supply while leaving the function for detecting wireless signals from communication device A for the path that relays wireless signals from communication device A, which has the next highest priority. After this setting is performed, the wireless signal transmitted from the base station device is transferred to communication device C via communication device A (S814, S815). Note that in a similar manner, a signal from communication device C can be transferred to the base station device via communication device A.

Then, the communication device A determines that a failure has occurred in the wireless section between the communication device C, for example, based on the fact that a signal addressed to the base station device from the communication device C has not arrived (S816). In this case, the communication device A performs settings for communication on a relay transmission path that reaches the communication device C via the communication device B, which has the next highest priority (S817). Based on the routing information received in S809, the communication device A may set a transmission beam pattern corresponding to the timing when the wireless signal from the communication device A was received most strongly or with a predetermined power or more in the communication device B. The communication device C may also determine that a failure has occurred in the wireless section between the communication device A, for example, based on the fact that a signal from the communication device A has not arrived (S818). In this case, the communication device C performs settings for communication on a relay transmission path that reaches the base station device via the communication device B, which has the next highest priority (S819). Based on the routing information received in S811, communication device C sets a receiving beam pattern that can receive, for example, the wireless signal from communication device B most strongly or at a predetermined power or higher.

The wireless signal transmitted from the base station device is then relayed by communication device A to reach communication device B, and then relayed by communication device B to reach communication device C (S820-S822). Note that communication device B, for example, determines in S821 that a switch in the communication path has occurred in response to receiving a wireless signal from communication device A at a predetermined power level or higher. Communication device B then turns on the communication function that was powered off, and sets it up to receive wireless signals from communication device A and transfer them to communication device C.

As described above, in this embodiment, the control device determines routing information based on the measurement results of wireless signals in each communication device, and each communication device sets up relaying of wireless signals based on that routing information, making it possible to quickly control communication path switching, etc.

<Embodiment 2>
In the above-described first embodiment, an example has been described in which the control device 121 performs processes such as identifying a relay transmission path in a centralized manner. In the present embodiment, an example in which the control device 121 is not used will be described.

In this embodiment, for example, each communication device transfers radio waves received from a base station device or the like while switching between multiple transmission beam patterns. Here, when transferring radio waves, the communication device transmits information indicating that the radio waves were received from a base station device and in which beam pattern the radio waves will be transmitted. Note that this information can be transmitted, for example, using a communication function separate from relay transmission. For example, the communication device can transmit this information using a terminal-to-terminal communication (D2D communication) function in LTE, 5G, or the like, or a cellular V2X (Vehicle-to-Everything) communication function. In one example, the communication device can broadcast information using the D2D communication function. Then, when the other communication device receives the information, it executes a detection process of the transferred radio waves. When the other communication device detects the transferred radio waves at a predetermined power or more, it notifies the communication device from which the radio waves are transferred of information indicating the detection result. At this time, the other communication device may also notify the communication device of information indicating which transmission beam pattern the communication device used to transfer the radio waves and detected the radio waves. At this time, the other communication device may use multiple reception beam patterns available to the device itself to identify the reception beam pattern that was able to detect the radio waves most strongly or with a predetermined power or higher, and notify the communication device of the identified beam pattern. The other communication device may identify the transmission beam pattern according to the timing of receiving the radio waves, for example.

For example, in the example of FIG. 9, the communication device 901 is capable of outputting radio waves arriving from a base station device with a plurality of beam patterns (beams 911 to 915). At this time, when the communication device 901 transfers radio waves arriving from the base station device using beam 911 in the first time interval, for example, the communication device 901 notifies surrounding communication devices of information capable of identifying the first time interval and beam 911 and information indicating that the radio waves arriving from the base station device will be transferred, for example, using the D2D communication function. Similarly, when the communication device 901 transfers radio waves arriving from the base station device using each of beams 912 to 915, for example, the communication device 901 notifies surrounding communication devices of information capable of identifying the time interval for transferring radio waves for each of beams 912 to 915 and information indicating that the radio waves arriving from the base station device will be transferred. When the communication device 902 and the communication device 903 receive this information, they perform a process of detecting the radio waves being transferred in the first time interval. At this time, it is assumed that the communication device 902 and the communication device 903 were unable to detect radio waves at a predetermined power or more. In this case, the communication device 902 and the communication device 903 end the process as it is. Next, the communication device 902 and the communication device 903 perform a detection process of radio waves transferred using the beam 912 in the second time period, for example. Here, it is assumed that the communication device 902 was able to detect the transferred radio waves at a predetermined power or more. In this case, since the communication device 902 was able to detect the radio waves in the second time period, it is possible to determine that the communication device 902 can receive the radio waves with sufficient power by the communication device 901 transferring the radio waves using the beam 912. In this case, the communication device 902 can notify the communication device 901 that the radio waves sent from the base station device have arrived at the communication device 902 via the beam 912 of the communication device 901, for example, using a D2D communication function. As a result, the communication device 901 can recognize that a relay transmission path of the base station device, the communication device 901, and the communication device 902 can be established by using the beam 912. Similarly, communication device 903 detects radio waves transferred via beam 914 and notifies communication device 901 that the radio waves sent from the base station device have reached communication device 903 via beam 914 of communication device 901. This allows communication device 901 to recognize that a relay transmission path can be established between the base station device, communication device 901, and communication device 903 by using beam 914. Note that communication devices 902 and 903 can further notify communication device 901 of information indicating the received power of the radio waves.

Next, the communication device 902 and the communication device 903 output the radio waves output from the communication device 901 in each of the available transmission beam patterns. For example, in FIG. 9, the communication device 902 transfers the radio waves using the beam 921 in the third time interval. At this time, the communication device 902 notifies the surrounding communication devices of information capable of identifying the third time interval and the beam 921, and information indicating that the radio waves are sent through a relay transmission path consisting of the base station device, the communication device 901, and the communication device 902, for example, using the D2D communication function. Here, it is assumed that the communication device 904 was able to detect the transferred radio waves with a predetermined power or more. In this case, since the communication device 904 was able to detect the radio waves in the third time interval, it can be determined that the communication device 904 can receive the radio waves with sufficient power by transferring the radio waves using the beam 921 in the communication device 902. In this case, the communication device 904 may notify the communication device 902 that the radio waves have reached the communication device 904 via the base station device and the communication device 901 and the beam 921 of the communication device 902. The communication device 902 may also forward this notification to the communication device 901. As a result, the communication devices 901, 902, and 904 can recognize that a relay transmission path of the base station device, the communication device 901, the communication device 902, and the communication device 904 can be established by using the beam 912 of the communication device 901 and the beam 921 of the communication device 902. In addition, information indicating the reception power of the radio waves at this time may be shared between the communication devices 901, 902, and 904. As a result, each communication device can share information on the relay transmission path that can be set. In addition, by sharing a predetermined rule that determines the priority, such as the higher the reception power of the radio waves, the higher the priority, the communication devices involved in the relay transmission path can share priority information.

FIG. 10 shows an example of the functional configuration of the communication device of this embodiment. Note that the hardware configuration example is the same as that of FIG. 5. The information communication unit 1001 communicates with other devices, for example, using a communication method different from the communication method for relaying communication of the base station device. In one example, the information communication unit 1001 broadcasts or group casts information indicating a path from the base station device to the device itself and information indicating that radio waves are output to identify the relay transmission path using the D2D communication function. In addition, the information communication unit 1001 receives information indicating a path from the base station device to the other device, which is broadcast or group cast transmitted from the other device, and information indicating that the other device outputs radio waves to identify the relay transmission path. The detection unit 1002 detects radio waves sent from the other device based on the received information. Note that, for example, when the other device outputs radio waves while switching the beam pattern for transmission, the detection unit 1002 can identify which beam pattern the detected radio waves were sent in based on the time period in which the radio waves were output in each beam pattern and the timing at which the radio waves were detected. In this case, it is sufficient to specify the index assigned to the beam pattern, and the communication device does not need to recognize the direction in which the radio wave was sent from the other device. For example, when the information communication unit 1001 detects radio waves from the other device, it notifies the other device of information indicating a new route that adds a section from the other device to the communication device to the route from the base station device to the other device notified from the other device. In addition, when the detection unit 1002 specifies the transmission beam pattern used by the other device to send the detected radio wave, the information communication unit 1001 includes information that can specify the beam pattern in the information indicating the new route and notifies the other device. The sending unit 1003 sends out radio waves to specify the relay transmission route. The sending unit 1003 can output radio waves in response to the information indicating the route from the base station device to the device itself and the information indicating that radio waves are output to specify the relay transmission route being sent by the information communication unit 1001. Furthermore, when a plurality of beam patterns for transmission are available, the sending unit 1003 outputs radio waves while switching between the beam patterns over time. In this case, the information communication unit 1001 transmits information indicating that radio waves are to be output to specify a relay transmission path, including information (e.g., an index) that can identify each beam pattern and information that associates the time interval during which radio waves are transmitted with the beam pattern, in information indicating that radio waves are to be output in order to specify a relay transmission path. The information communication unit 1001 receives information indicating a new path that adds an interval from the communication device to the other device to the path from the base station device to the communication device from the other device that detected the transmitted radio waves. The information communication unit 1001 may obtain information indicating the new path that can identify the beam pattern for transmission of the own device from the information indicating the new path. For example, when the detection unit 1002 detects radio waves from the other device, the routing control unit 1004 holds information on the relay transmission path from the base station device to the communication device via the other device as routing information. In addition, even if the routing control unit 1004 receives information indicating a new route from another device, which route is from a base station device to another device via a communication device, as a result of, for example, transmitting radio waves by the transmitting unit 1003, the routing control unit 1004 holds the information of the new route as routing information. Then, the routing control unit 1004 determines the route to be used for communication based on the information held, and sets, for example, the beam pattern corresponding to the route to be used. Note that, for example, the routing control unit 1004 may assign priorities based on the wireless quality of each route. In this case, the routing control unit 1004 uses the routing information with the highest priority to set up relaying. Also, for example, when the wireless quality of communication using the setting in use has deteriorated, the routing control unit 1004 sets up using the routing information with the next highest priority, and switches the relay transmission route. Note that information on the beam pattern for transmission to be used in each communication device may be included in the header of the physical layer in the wireless signal, and the routing control unit 1004 may set the antenna pattern to be used for each wireless signal based on the information. Note that, in this case, the information on each route is also notified to the base station device. Also, information indicating which communication device the wireless signal should be forwarded to may be included in the header of the physical layer of the wireless signal. In this case, for example, when the routing control unit 1004 receives a wireless signal including information indicating that the signal should be forwarded to its own device, the routing control unit 1004 may perform a setting so as not to relay the wireless signal.

An example of the flow of the process executed in this embodiment will be described with reference to FIG. 11. It is assumed that the communication device A detects radio waves transmitted by "beam 1" among a plurality of beams that the base station device can form (S1101). The communication device A notifies other surrounding communication devices that it will relay the radio waves of beam 1, and that it will identify the transmission beam that the device will use when relaying, and the information on the time period in which the beam will be used, using, for example, a D2D communication function (S1102). Here, it is assumed that the communication device A has been notified that it will relay the radio waves of beam 1 using beam A1 in the first time period and beam A2 in the second time period. Then, the communication device A relays the radio waves of beam 1 using beam A1 in the first time period and beam A2 in the second time period (S1103, S1104). It is assumed that the communication device B has been able to detect radio waves in, for example, the second time period. In this case, communication device B notifies communication device A that it has detected radio waves transmitted from beam 1 of the base station device and relayed by beam A2 of communication device A, and the radio quality of the detected radio waves (e.g., RSRP, RSRQ, SNR, etc.) (S1105). This allows communication device A to recognize that it is possible to form a relay transmission path consisting of the base station device, communication device A, and communication device B by using beam A2.

Then, the communication device B executes relaying of the radio wave received from the communication device A. At that time, the communication device B notifies other surrounding communication devices, for example, using the D2D communication function, that it will relay the radio wave that was sent from the base station device by beam 1 and arrived via beam A2 of the communication device A, and that it will notify the other surrounding communication devices of information that can identify the transmission beam that the communication device will use when relaying and information on the time period in which the beam will be used (S1106). Here, it is assumed that the communication device B has been notified that it will relay the radio wave that arrived from the communication device A using beam B1 in the third time period and beam B2 in the fourth time period. Then, the communication device B relays the radio wave of beam 1 using beam B1 in the third time period and beam B2 in the fourth time period (S1107, S1108). It is assumed that the communication device C was able to detect the radio wave in both the third time period and the fourth time period, for example. In this case, communication device C notifies communication device B that it has detected radio waves transmitted from beam 1 of the base station device and relayed by beam A2 of communication device A and beam B1/beam B2 of communication device B, and the radio quality of the detected radio waves (e.g., RSRP, RSRQ, SNR, etc.) (S1109). Communication device B also transfers the notified information to communication device A. This allows communication device A and communication device B to recognize that a relay transmission path consisting of the base station device, communication device A, communication device B, and communication device C can be formed by communication device A using beam A2 and communication device B using beam B1 or beam B2.

In addition, by being notified of the wireless quality when beam B1 is used and the wireless quality when beam B2 is used, it is possible to determine which beam is used as the relay transmission path to be given higher priority. Note that in the example of FIG. 11, an example is shown in which the radio waves sent by communication device A do not reach communication device C, but the radio waves may reach communication device C directly. In that case, communication device C may execute the same process as the process executed by communication device B in S1105. Communication device A can then determine whether to prioritize the path via communication device B or the path not via communication device B, for example, based on the wireless quality information received from communication device B and communication device C, respectively.

In the above example, the communication device A amplifies and outputs radio waves received from the base station device, and the communication device B etc. amplifies and outputs radio waves arriving from the communication device A, but the present invention is not limited to this. For example, when a dedicated measurement period is provided, the radio waves output by each communication device may be measurement radio waves generated by that communication device. In this case, for example, the communication device A can receive radio waves (for example, SSB or reference signal) sent from the base station device outside the measurement period. For this reason, the communication device A transmits information indicating the existence of a direct communication path with the base station device, information indicating a beam that the device can form, and information on the period for outputting radio waves with that beam to other surrounding communication devices, for example, by D2D communication. The subsequent processing is the same as the above example.

As described above, in this embodiment, relay transmission path information can be shared between multiple communication devices without going through a control device. This makes it possible to set the relay transmission path that was set under the control of the control device in embodiment 1 by processing by the communication device without going through the control device.

As described above, according to each of the above-mentioned embodiments, advanced and efficient control of mesh networks involving layer 1 relay transmission is possible. This makes it possible to contribute to Goal 9 of the United Nations-led Sustainable Development Goals (SDGs), which is to "build resilient infrastructure, promote sustainable industrialization and foster innovation."

The invention is not limited to the above-described embodiment, and various modifications and variations are possible within the scope of the invention.

Claims (7)

1. A communication device, comprising:
A relay unit that relays a wireless signal transmitted from a base station device as a wireless repeater in a physical layer ;
A communication means for communicating with another device that relays the wireless signal transmitted from the base station device;
having
the communication means receives, from the first other device, first information indicating a first path along which the wireless signal travels from the base station device to the first other device and indicating that a radio wave is to be transmitted;
The relay means detects radio waves output from the first other device based on the first information,
when the communication means is able to detect the radio wave output from the first other device, notifies the first other device of second information indicating a second route obtained by adding a section from the first other device to the communication device to the first route;
the relay means relays the wireless signal transmitted from the base station device along the second route and received from the first other device;
A communication device comprising: the first other device is capable of using a plurality of beams for transmission;
the first information includes information indicating a time interval during which the first other device transmits the wireless signal using each of the plurality of transmission beams;
when the relay means detects a radio wave output from the first other device, the relay means identifies which of the plurality of transmission beams the radio wave was transmitted using based on a timing of the detection;
the communication means notifies the first other device of information indicating that the second path is formed using a beam identified in the first other device as the second information;
2. The communication device according to claim 1 . the communication means transmits third information indicating the second route and indicating that the communication device transmits radio waves;
The relay means outputs radio waves based on the third information,
the communication means receives fourth information indicating a third route obtained by adding a section from the communication device to the second other device to the second route from a second other device that has detected the radio wave output by the relay means;
The communication means transfers the fourth information to the first other device;
the relay means relays the wireless signal transmitted from the base station device and received from the first other device to the second other device along the third route.
2. The communication device according to claim 1 . the communication device is capable of using a plurality of beams for transmission;
the third information includes information indicating a time interval during which the communication device transmits the radio signal using each of the plurality of transmission beams;
the communication means receives, as the fourth information, information indicating that the third route is formed using a beam identified based on a timing at which the radio wave transmitted by the relay means is detected in the second other device, from the second other device;
4. The communication device according to claim 3. The communication device according to claim 1, characterized in that the communication method used by the relay means is different from the communication method used by the communication means. A control method executed by a communication device having a relay means for relaying a radio signal transmitted from a base station device as a radio repeater in a physical layer , and a communication means for communicating with another device that relays the radio signal transmitted from the base station device, comprising:
receiving, from the first other device by the communication means , first information indicating a first route along which the wireless signal travels from the base station device to the first other device and indicating that a radio wave is to be transmitted;
detecting, by the relay means, a radio wave output from the first other device based on the first information;
when detecting the radio wave output from the first other device, notifying the first other device by the communication means of second information indicating a second route obtained by adding a section from the first other device to the communication device to the first route;
relaying , by the relay means, the wireless signal transmitted from the base station device along the second route and received from the first other device;
A control method comprising: A computer is provided in a communication device having a relay means for relaying a radio signal transmitted from a base station device as a radio repeater in a physical layer , and a communication means for communicating with another device that relays the radio signal transmitted from the base station device,
receiving, by the communication means , first information from the first other device, the first information indicating a first route along which the wireless signal travels from the base station device to the first other device and indicating that a radio wave is to be transmitted;
detecting, by the relay means, radio waves output from the first other device based on the first information;
when detecting the radio wave output from the first other device, notifying the first other device by the communication means of second information indicating a second route obtained by adding a section from the first other device to the communication device to the first route;
relaying , by the relay means, the wireless signal transmitted from the base station device along the second route and received from the first other device;
Program for.

Images