Base station device, relay station device, communication control method, and communication control program

Abstract

To provide a base station device, a relay station device and a communication control method in order to reuse a communication resource, having low interference possibility among allocated communication resources, for communication between the relay station device and a communication terminal device in a shield space.SOLUTION: A base station device 1 communicates with a communication terminal device through the relay station device, provided in the shield space, which can simultaneously perform downstream side communication with the communication terminal device in the shield space and upstream side communication with the base station device 1. The base station device 1 allocates a communication resource to be used for communication with the relay station device, and on the basis of reuse requirements based on radio wave shielding ability in the shield space, identifies a reuse resource r(N) among allocated resources P(N), which is reusable for the communication between the relay station device and the communication terminal device, so as to transmit the reuse resource r(N) to the relay station device.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a base station apparatus, a relay station apparatus, and the like that reuses allocated communication resources to perform efficient data transmission and reception in communication with a communication terminal apparatus via a relay station apparatus. [Background technology]

[0002] As wireless communication becomes more widespread, opportunities to communicate using wireless communication are increasing in various places. In particular, for moving objects such as automobiles, technologies for driving assistance and autonomous driving control using large-capacity cellular communication and V2X such as vehicle-to-vehicle communication and road-to-vehicle communication are attracting attention. Accordingly, there is a demand for efficient use of communication resources to improve the efficiency of frequency utilization.

[0003] For example, Patent Document 1 describes the application of segmented frequency reuse and power defensive beamforming to mitigate interference introduced by mobile relay nodes in a heterogeneous network. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Special Publication No. 2015-534782 Summary of the Invention [Problem to be solved by the invention]

[0005] Here, the present inventors have found the following problem. In a configuration where the relay node moves, it is necessary to dynamically track the movement of the relay node to avoid interference. Since the coverage of the relay node is not uniform with respect to the distance from the mobile in a fading environment, it is necessary to share frequencies with a sufficient margin, which makes it difficult to improve the reuse efficiency. In addition, the communication between the donor macrocell BS and the relay node and the communication between the relay node and the mobile cannot share time and frequency.

[0006] The present invention aims to effectively utilize communication resources by identifying communication resources from among allocated communication resources that are less likely to interfere, and reusing them for communication between a relay station device and a communication terminal device in a shielded space, thereby enabling efficient transmission and reception of data. [Means for solving the problem]

[0007] A base station device (1) according to the present disclosure is a base station device (1) that communicates with a communication terminal device (23) in a shielded space (20) via a relay station device (2) that can simultaneously perform downstream communication with the communication terminal device (23) in the shielded space (20) using a downstream antenna (22) provided in the shielded space, and upstream communication with the base station device using an upstream antenna (21) provided outside the shielded space, a resource allocation unit (122) for allocating communication resources used for communication between the relay station device and the base station device or communication between another relay station device and the base station device; The allocated resources, which are the communication resources allocated by the resource allocation unit, can be reused in the downstream communication between the relay station device and the communication terminal device. Requirements to be A reference radio wave that constitutes a reference shielded space shielding a reuse requirement storage unit (132) that stores reuse requirements classified as to whether or not the reuse is possible based on a reference radio wave shielding ability of a structure; The radio waves from the relay station device to the radio wave shielding structure forming the shielded space shielding A relay station information acquisition unit (121) for acquiring information on a relay station; The communication resources to be used for the downstream communication between the relay station device and the communication terminal device are selected from the allocated resources. shielding A reuse resource identification unit (123) that identifies the reuse resource that satisfies the reuse requirement; and a transmission instruction unit (124) for instructing the relay station device to transmit the reused resource.

[0008] A relay station device (2, 2A) according to the present disclosure is a relay station device (2) that simultaneously performs downstream communication with a communication terminal device (23) in a shielded space (20) using a downstream antenna (22) provided in the shielded space, and upstream communication with a base station device (1) using an upstream antenna (21) provided outside the shielded space, and relays communication between the communication terminal device and the base station device, Radio waves that form the shielded space shielding A relay station information storage unit (261) for storing the radio wave shielding ability of the structure; A connection request instruction unit (251) that transmits the radio wave shielding capability to the base station device; The radio wave identified from among allocated resources, which are communication resources allocated to communication between the relay station device and the base station device or communication between another relay station device and the base station device. shielding a reuse resource acquisition unit (254) for acquiring reuse resources that satisfy reuse requirements from the base station device; a reuse resource allocation unit (255) that allocates the reuse resources to communication between the relay station device and the communication terminal device, The reuse requirement is that the allocated resources can be reused in the downstream communication between the relay station device and the communication terminal device. Requirements to be A reference radio wave that constitutes a reference shielded space shielding The feasibility of reuse is classified based on the standard radio wave shielding ability of the structure.

[0009] In addition, the claims and the numbers in parentheses attached to the constituent elements of the invention described in this section indicate the correspondence between the present invention and the embodiments described below, and are not intended to limit the present invention. Effect of the Invention

[0010] With the above-mentioned configuration, it is possible to reuse, for downstream communication, the communication resources that are unlikely to interfere with downstream communication with the communication terminal device in the shielded space in which the relay station device is installed, among the allocated communication resources. Therefore, it is possible to suppress the decrease in resource efficiency due to relaying by the relay station device, and to transmit and receive data efficiently. [Brief description of the drawings]

[0011] [Figure 1] FIG. 1 is a diagram showing an overall configuration of an embodiment of the present disclosure. [Diagram 2] FIG. 1 is a block diagram showing a configuration example of a base station device according to a first embodiment of the present disclosure. [Diagram 3] Flowchart showing the operation of a base station device according to the first embodiment of the present disclosure. [Figure 4] FIG. 1 is a block diagram showing a modified configuration of a base station device according to a first embodiment of the present disclosure. [Diagram 5] A flowchart showing a modified example of the operation of the base station device according to the first embodiment of the present disclosure. [Figure 6] FIG. 11 is a block diagram showing a configuration example of a relay station device according to a second embodiment of the present disclosure. [Figure 7] Flowchart showing the operation of the relay station device according to the second embodiment of the present disclosure. [Figure 8] A diagram illustrating a reuse table as a concrete example of reuse requirements. [Figure 9] (a)(b) is an explanatory diagram explaining reuse of communication R1 in FIG. 8. [Figure 10] (a)(b) is an explanatory diagram illustrating the reuse (upstream) of communication R2 in FIG. 8. [Figure 11] (a)(b) is an explanatory diagram explaining the reuse of communication R3 in FIG. 8. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0013] The present invention means the invention described in the claims or in the Summary of the Invention section, and is not limited to the following embodiments. Furthermore, at least the words in quotation marks mean the words described in the claims or in the Summary of the Invention section, and are not limited to the following embodiments.

[0014] The configurations and methods described in the dependent claims are optional configurations and methods in the invention described in the independent claims. The configurations and methods of the embodiments corresponding to the configurations and methods described in the dependent claims, and the configurations and methods described only in the embodiments without being described in the claims, are optional configurations and methods in the present invention. The configurations and methods described in the embodiments when the description of the claims is broader than the description of the embodiments are also optional configurations and methods in the present invention in the sense that they are examples of the configurations and methods of the present invention. In either case, by being described in the independent claims, they become essential configurations and methods of the present invention.

[0015] The effects described in the embodiments are effects obtained when the configurations of the embodiments are provided as examples of the present invention, and are not necessarily effects that the present invention possesses.

[0016] When there are multiple embodiments, the configurations disclosed in each embodiment are not limited to each embodiment, but can be combined across the embodiments. For example, a configuration disclosed in one embodiment may be combined with another embodiment. Also, configurations disclosed in each of the multiple embodiments may be collected and combined.

[0017] The problem described in the section on problems that the invention is intended to solve is not a publicly known problem, but was discovered independently by the inventor, and this, together with the configuration and method of the present invention, is a fact that affirms the inventive step of the invention.

[0018] 1. Overall configuration examples of each embodiment First, with reference to FIG. 1, devices related to each embodiment and their interrelationships, as well as an example of the overall configuration of each embodiment will be described.

[0019] The base station device 1 is a device that performs wireless communication with a communication terminal device 23 in a shielded space 20 in which the relay station device 2 is installed, via the relay station device 2. The base station device 1 can also perform wireless communication with the communication terminal device 23 in the shielded space 20 without going through the relay station device 2. Here, the term "base station device" refers to a device installed as a relay point for communication terminal device 23 and connected to a backbone network, but in cases where some of the processing or functions are realized by various server devices at the other end of the backbone network, the term refers to the entire device including those various server devices. In addition, a "shielded space" refers to a space that is completely shielded, as well as a space that is shielded from the outside and inside. By using shielding materials to separate the inside and outside of the space There may be some attenuation of the radio waves. For convenience, in the drawings, the base station device, relay station device, communication terminal device, and communication resources are abbreviated as base station, relay station, terminal, and resource, as appropriate.

[0020] The relay station device 2 is in a shielded space 20 To The relay station device 2 is provided with an upstream antenna 21 for performing upstream communication with the base station device 1, and a downstream antenna 22 for performing downstream communication with a communication terminal device 23 in the shielded space 20. The relay station device 2 can perform upstream communication and downstream communication simultaneously. Here, "simultaneous" includes cases where the events are the same in time as well as cases where the events are consecutive in time.

[0021] The shielded space 20 is a shielded space with a known radio wave shielding structure (radio wave shielding ability), and examples of such include a space in which seats are provided in an automobile, a hall or a room in a building, etc. The downstream antenna 22 is provided in the shielded space 20. Therefore, if the radio wave shielding ability of the shielded space 20 is known, it is possible to evaluate the possibility of interference between downstream communication in the shielded space 20 and other communication outside the shielded space 20 based on the radio wave shielding ability. Examples of the radio wave shielding ability include the distance from the relay station device 2 at which radio waves are attenuated to a predetermined strength, the attenuation rate of radio waves, etc.

[0022] From here on, the relay station device 2A in the vehicle A will be described. The base station device 1 evaluates the interference potential between downstream communication between the relay station device 2A and the communication terminal device 23A in the shielded space 20A and other communications based on the radio wave shielding capability of the shielded space 20A. Based on this interference potential evaluation, among the communication resources already allocated to other communications, those determined to have a low possibility of interference with downstream communications are reallocated to downstream communications. Here, examples of other communications include communication R1 between the relay station device 2A and the base station device 1, communication R2 between the base station device 1 and the relay station device 2B, communication R3 between the relay station device 2B and the communication terminal device 23B, and communication R4 between the base station device 1 and the communication terminal device 23B not via the relay station device 2B.

[0023] The relay station device 2A is configured to recognize and communicate with the communication terminal device 23A performing downstream communication in the shielded space 20A, via the downstream antenna 22 located in the shielded space 20A in which a radio wave shielding structure is specified. Then, the relay station device 2A notifies the base station device 1 performing upstream communication of the number of connections of the communication terminal device 23 performing downstream communication that it has grasped.

[0024] When the communication terminal device 23A is a smartphone, a mobile phone, a tablet, or the like, it performs wireless communication with a wireless communication unit of the relay station device 2A, and performs wireless communication with the base station device 1 via the relay station device 2A. For the wireless communication, in addition to the examples of communication methods described later, short-range wireless communication such as BLE or Bluetooth (registered trademark) can be used.

[0025] Based on the information of communication terminal device 23A notified from relay station device 2A, base station device 1 allocates communication resources to relay station device 2A, communication terminal device 23A, and communication (downstream communication) T. At this time, based on the shielding structure of shielded space 20A, communications that are determined to have no interference with communication T or are sufficiently weak are extracted from among other already allocated communications R1 to R4. Then, communication resources already allocated to other communications R1 to R4 are preferentially allocated to communication T as reused resources, and notified to relay station device 2A.

[0026] This allows the relay station device 2A to allocate reuse resources to each communication terminal device 23A. For example, when the shielded space 20A has a high radio wave shielding ability, the radio waves of the communication T in the shielded space 20 are attenuated sufficiently at the position of the upstream antenna 21 provided outside the shielded space 20A. Therefore, when the relay station device 2A performs communication R1 with the base station device 1 exclusively via the upstream antenna 21, the base station device 1 can preferentially allocate the communication resources already allocated to the communication R1 to the communication T as reuse resources.

[0027] The wireless communication system between the base station device 1 and the relay station device 2, between the relay station device 2 and the communication terminal device 23, and between the base station device 1 and the communication terminal device 23 may be, for example, IEEE802.11 (WiFi (registered trademark)), IEEE802.16 (WiMAX (registered trademark)), W-CDMA (Wideband Code Division Multiple Access), HSPA (High Speed ​​Packet Access), LTE (Long Term Evolution), LTE-A (Long Term Evolution Advanced), 4G, 5G, etc. Alternatively, DSRC (Dedicated Short Range Communication) may be used.

[0028] 2. Embodiment 1 (1) Configuration of Base Station Device 1 The configuration of the base station device 1 of the first embodiment will be described with reference to FIG. The base station device 1 includes a wireless communication unit 11, a control unit 12, and a storage unit 13.

[0029] The wireless communication unit 11 performs "wireless communication" with the relay station device 2, which is an external communication device, and the communication terminal device 23. As described above, various communication methods can be used for the wireless communication method, but in this embodiment, 4G or 5G is assumed as the cellular communication method. Note that the wireless communication method may be compatible with multiple communication methods. Here, "wireless communication" refers to transmitting and / or receiving signals wirelessly.

[0030] The control unit 12 realizes a relay station information acquisition unit 121, a resource allocation unit 122, a reused resource specification unit 123, and a transmission instruction unit . The relay station information acquisition unit 121 acquires information about the relay station device 2, such as the radio wave shielding capability of the shielded space 20, a list of the communication terminal devices 23 accommodated, etc. (see FIG. 1). The resource allocation unit 122 allocates communication resources to the communication between the relay station device 2 and the base station device 1.

[0031] The reuse resource identification unit 123 uses the radio wave shielding ability acquired from the relay station device 2 and the reuse requirements in the reuse requirement storage unit 132 to identify reuse resources that satisfy the reuse requirements from among the allocated resources allocated by the resource allocation unit 122. The transmission instruction unit 124 instructs the relay station device 2 to transmit the allocated resources and the reused resources.

[0032] The storage unit 13 may be, for example, a non-volatile memory such as a flash memory or a hard disk, or a volatile memory such as a RAM. A removable storage medium such as a BD, DVD, or SD card may also be used. The storage unit 13 realizes a relay station information storage unit 131, a reuse requirement storage unit 132, and a communication resource storage unit 133.

[0033] The relay station information storage unit 131 stores the acquired information about the relay station device 2. The information about the relay station device 2 includes the radio wave shielding capability of the shielded space 20, a terminal list of the communication terminal devices 23 accommodated in the shielded space 20, information about data reception to the communication terminal devices 23, information about resource allocation request reception from the relay station device 2, and the like.

[0034] The reuse requirement storage unit 132 stores reuse requirements based on the radio wave shielding capability of the shielded space 20. Examples of reuse requirements include the distance from the relay station device 2 at which the radio wave strength of downstream communication attenuates to a predetermined value (attenuation distance), the attenuation rate of the radio wave strength of downstream communication depending on the distance from the relay station device 2, and the distance between relay station devices specified corresponding to the attenuation distance or attenuation rate. The reuse requirement storage unit 132 uses these alone or in combination as reuse requirements.

[0035] The communication resource storage unit 133 stores communication resources and allocation of communication resources used for communication of the base station device 1. Examples of information regarding the allocation of communication resources include a resource set already allocated for communication outside the shielded space 20, a communication resource set that is among the allocated communication resource sets and can be reused for communication inside and outside the shielded space 20, and an unallocated communication resource set.

[0036] (2) Operation of Base Station Device 1 The operation of the base station device 1 of this embodiment will be described with reference to the flowchart of FIG. The following operations not only indicate a communication control method executed by the base station device 1 but also indicate a processing procedure of a communication control program executable by the base station device 1. The order of these processes is not limited to the order shown in Fig. 3. In other words, the order may be changed as long as there is no constraint such as a relationship in which a step uses the result of a previous step.

[0037] When receiving a connection request (attach request) from the relay station device 2, the relay station information acquisition unit 121 of the base station device 1 acquires the radio wave shielding ability of the shielded space 20 in which the relay station device 2 is installed from the attribute information of the relay station device 2 included in the connection request, and transmits an acknowledgement to the relay station device 2 (S101). In this way, the base station device 1 acquires the radio wave shielding ability of the shielded space 20 of the relay station device 2, and stores it in the relay station information storage unit 131.

[0038] The relay station information acquisition unit 121 receives and acquires from the relay station device 2 an update of the terminal list of the communication terminal devices 23 accommodated therein, and transmits an acknowledgement to the relay station device 2 (S102). In this manner, the base station device 1 receives the update of the communication terminal devices 23 from the relay station device 2 and stores it in the relay station information storage unit 131, thereby maintaining the terminal list accommodated by the relay station device 2 in the latest state.

[0039] The relay station information acquisition unit 121 receives data to communication terminal device 23 of relay station device 2 from the backbone network, or receives a resource allocation request from relay station device 2 (S103). Receiving data to communication terminal device 23 in the case of downstream communication from base station device 1, or receiving a resource allocation request from relay station device 2 in the case of upstream communication to base station device 1, triggers allocation of resource set P(N) (S104) and identification of reused resource set R(N) (S106). The information received by relay station information acquisition unit 121 is stored in relay station information storage unit 131.

[0040] The resource allocation unit 122 allocates a resource set P(N), which is a set of communication resources r, to communication between the base station device 1 and the relay station device 2 and the communication terminal device 23 (S104). The resource set P(N) is stored in the communication resource storage unit 133. Here, the allocated resource set P(N) is a set of communication resources defined by frequency, time, code, etc., and corresponds to the "allocated resource" of the present invention. For example, if fi is the i-th frequency slot and ti is the i-th time slot, an example of a communication resource is indicated by a combination (fi, ti) of a specific frequency slot and time slot. Also, an example of the resource set P(N) is indicated by a set of combinations of specific frequency slots and time slots {(f1, t1), (f3, t2), (f5, t7)}.

[0041] The reuse resource specifying unit 123 initializes a reuse resource set R(N) that can be reused for downstream communication between the relay station device 2 and the communication terminal device 23, out of the allocated resource set P(N) (S105).

[0042] The reuse resource specifying unit 123 judges whether the communication resource r in the resource set P(N) in the communication resource storage unit 133 satisfies the reuse requirements, and adds the communication resource r that satisfies the reuse requirements to the reuse resource set R(N). This judgment is repeated for all resource sets P(N), and identifies the reuse resource set R(N) that satisfies the reuse requirements from the resource set P(N) that has been allocated by the resource allocation unit (S106). The reuse resource set R(N) is stored in the communication resource storage unit 133.

[0043] S106 is a loop for identifying a reuse resource set R(N) from the allocated resource set P(N), and if the communication (communication link) requested for allocation satisfies the reuse requirements, the communication resource r included in the resource set P(N) is added to the reuse resource set R(N). This is performed for all communications to which the communication resource r has already been allocated. The reuse requirements are stored in the reuse requirement storage unit 132, for example, as a table that identifies the relationships that enable reuse.

[0044] The transmission instruction unit 124 acquires the resource set P(N) and the reused resource set R(N) from the communication resource storage unit 133, and transmits them via the wireless communication unit 11 to the relay station device 2 that is the destination of the downlink data received in S103 or the source of the resource allocation request for the uplink data (S120).

[0045] (3) Modification of Base Station Device 1 As shown in FIG. 4, the control unit 12 of the base station device 1 may realize a new resource allocation unit 125 in addition to a relay station information acquisition unit 121, a resource allocation unit 122, a reused resource specification unit 123, and a transmission instruction unit 124. When receiving data for communication terminal apparatus 23 accommodated by relay station apparatus 2 or a resource allocation request from relay station apparatus 2, if the reuse resource set R(N) is insufficient, new resource allocation unit 125 allocates unallocated resources other than the allocated resource set P(N) as a new resource set U(N) to cover the shortage in downstream communication of relay station apparatus 2.

[0046] When the reused resource set R(N) is insufficient for the resource allocation request, the transmission instruction unit 124 instructs the relay station device 2 to transmit a new resource set U(N) consisting of unallocated resources in addition to P(N) and R(N).

[0047] (4) Operation of the Modified Example of Base Station Apparatus 1 The operation of the modified example of the base station device 1 of the present embodiment will be described with reference to the flowchart of FIG. In a modified example of the base station device 1, after identifying the reuse resource set R(N) (S106), the new resource allocation unit 125 determines (S107) whether the total amount of resources in R(N) is less than the required amount of allocation corresponding to the data or resource allocation request received by the base station device 1 (S103).

[0048] If the total amount of resources in the reuse resource set R(N) is less than the amount required for allocation (Y (Yes) in S107), the process proceeds to S108. The new resource allocation unit 125 allocates the unallocated communication resources other than the resource set P(N) to a new resource set U(N) to make up for the shortage (S108). The new resource set U(N) is stored in the communication resource storage unit 133.

[0049] If the total amount of resources in the reuse resource set R(N) is equal to or greater than the required amount to be allocated (N (No) in S107), the process proceeds to S109. The new resource allocation unit 125 initializes the new resource set U(N) as an empty set (=φ) (S109).

[0050] The transmission instruction unit 124 obtains the allocated resource set P(N), the reused resource set R(N), and the new resource set U(N) from the communications resource storage unit 133, and instructs the relay station device 2 to transmit them (S130). By the base station device 1 transmitting a new resource set U(N) to the relay station device 2 in addition to the already allocated resource set P(N) and the reused resource set R(N), the relay station device 2 can use the new resources that were not allocated to the resource set P(N) for communication with the communication terminal device 23 when necessary.

[0051] As described above, according to the base station device 1, the communication control method, and the data communication control program of the present embodiment, communication resources with low interference potential are identified based on the radio wave shielding capability of the shielded space, and the identified communication resources are reused for communication within the shielded space, thereby suppressing a decrease in the utilization efficiency of communication resources due to relaying. In addition, since the base station device 1 is not concerned with the allocation of communication resources to individual communication terminal devices 23 by the relay station device 2, the processing cost of the base station device 1 and the control information required for communication between the base station device 1 and the relay station device 2 can be reduced.

[0052] 3. Embodiment 2 (1) Configuration of relay station device 2 The configuration of the relay station device 2 according to the second embodiment will be described with reference to FIG. The relay station device 2 simultaneously performs downstream communication with a communication terminal device 23 (see FIG. 1) in the shielded space 20 and upstream communication with the base station device 1, and relays communication between the communication terminal device 23 and the base station device 1. To It will be established.

[0053] The relay station device 2 includes an upstream antenna 21, a downstream antenna 22, a wireless communication unit 24, a control unit 25, and a storage unit .

[0054] The relay station device 2 can be configured with a general-purpose CPU (Central Processing Unit), a volatile memory such as a RAM, a non-volatile memory such as a ROM, a flash memory, or a hard disk, various interfaces, and an internal bus connecting these. Then, by executing software on these hardware, the relay station device 2 can be configured to perform the functions of each functional block shown in FIG. 6. Of course, the relay station device 2 may be realized by dedicated hardware such as an LSI.

[0055] The relay station device 2 may have any of the following forms: a component, a semi-finished product, and a finished product. For example, the component form may be a semiconductor circuit or a semiconductor module, the semi-finished product form may be an electronic control device (ECU (Electric Control Unit), hereinafter abbreviated as ECU), and the finished product form may be a personal computer (PC), a smartphone, a mobile phone, or a navigation system.

[0056] The wireless communication unit 24 performs upstream communication with the base station device 1 via the upstream antenna 21 by wireless communication, and performs downstream communication with the communication terminal device 23 in the shielded space 20 via the downstream antenna 22 (see Figure 1).

[0057] The control unit 25 realizes a connection request instruction unit 251 , a terminal list update unit 252 , a terminal list transmission unit 253 , a reused resource acquisition unit 254 , a reused resource allocation unit 255 , and a transmission instruction unit 256 .

[0058] When making a connection request to the base station device 1, the connection request instruction unit 251 transmits attribute information of the shielded space 20 including the radio wave shielding ability of the shielded space 20 from the relay station information storage unit 261 of the storage unit 26, and receives a confirmation response from the base station device 1. This enables the base station device 1 to identify the reuse resource set R(N) from the allocated resource set P(N) using the radio wave shielding ability of the shielded space 20. The terminal list update unit 252 updates the accommodated terminal list in the relay station information storage unit 261 when it receives a connection request from a new communication terminal device 23 or detects the disconnection of a previously connected communication terminal device 23 . The terminal list transmission unit 253 transmits the updated accommodated terminal list to the base station device 1 and receives an acknowledgement from the base station device 1.

[0059] The reuse resource acquisition unit 254 acquires reuse resources that satisfy the reuse requirements based on the radio wave shielding capability of the shielded space 20 from the base station device 1. The reuse resources are stored in the communication resource storage unit 262. The reused resource allocation unit 255 acquires reused resources and allocates them to downstream communication between the relay station device 2 and the communication terminal device 23. The transmission instruction unit 256 instructs the communication terminal device 23 in the shielded space 20 to transmit the result of the allocation of the reused resources.

[0060] The storage unit 26 may be a non-volatile memory such as a flash memory or a hard disk, or a volatile memory such as a RAM. A removable storage medium such as a BD, DVD, or SD card may also be used. The storage unit 26 realizes a relay station information storage unit 261 and a communication resource storage unit 262.

[0061] The relay station information storage unit 261 stores the radio wave shielding capability of the shielded space, a list of communication terminals accommodated in the shielded space, and the like. The communication resource storage unit 262 stores information about communication resources received from the base station device 1. The information includes a resource set P(N) consisting of allocated resources, a reused resource set R(N), and a new resource set U(N), etc.

[0062] (2) Operation of relay station device 2 The operation of the relay station device 2 of this embodiment will be described with reference to the flowchart in Fig. 7. Note that the following operation not only indicates a communication control method executed by the relay station device 2, but also indicates a processing procedure of a communication control program executable by the relay station device 2. The order of these processes is not limited to the order shown in Fig. 7. In other words, the order may be changed as long as there is no constraint such as a relationship in which a certain step utilizes the result of the previous step.

[0063] The connection request instruction unit 251 of the relay station device 2 detects the base station device 1 (S201), transmits a connection request with attribute information including the radio wave shielding capability of the shielded space 20 (see FIG. 1) to the base station device 1, and receives an acknowledgement response from the base station device 1 (S202).

[0064] The terminal list update unit 252 receives a connection request from a new communication terminal device 23, or detects the disconnection of a communication terminal device 23 currently connected by downstream communication (S203). Then, it updates the terminal list of the communication terminal devices 23 accommodated in the shielded space 20 (S204). The terminal list is stored in the relay station information storage unit 261. The terminal list transmission unit 253 transmits the terminal list acquired from the terminal list update unit 252 or the relay station information storage unit 261 to the base station device 1, and receives an acknowledgement from the base station device 1 (S205).

[0065] The reused resource acquisition unit 254 receives the resource set P(N) and the reused resource set R(N), or the resource set P(N), the reused resource set R(N), and the new resource set U(N) from the base station device 1 (S206). The reused resource allocation unit 255 determines the allocation of resources included in the reused resource set R(N) or the reused resource set R(N) and the new resource set U(N) for each communication terminal device 23 accommodated in the shielded space 20 (S207). The transmission instruction unit 256 transmits to the communication terminal device 23 the result of allocating the resources included in the reuse resource set R(N) or the result of allocating the resources included in the reuse resource set R(N) and the new resource set U(N).

[0066] As described above, according to the relay station device 2, the communication control method, and the communication control program of the present embodiment, by transmitting a connection request to the base station device 1 with the radio wave shielding capability of the shielded space 20 attached thereto, the base station device 1 can identify communication resources with a low possibility of interference with downstream communication in the shielded space 20. By reusing communication resources with a low possibility of interference for downstream communication in the shielded space 20, it is possible to suppress a decrease in the utilization efficiency of communication resources due to relaying by the relay station device 2. Furthermore, by the base station device 1 being unaware of the allocation of communication resources to individual communication terminal devices 23 by the relay station device 2, it is possible to reduce the processing cost of the base station device 1 and the control information required for communication between the base station device 1 and the relay station device 2.

[0067] 4. Specific examples of reuse requirements An example of a reuse table, which is an example of reuse requirements, will be described with reference to Fig. 8. The reuse table specifies classification of communication T for which new communication resources are allocated and communication R for which communication resources have already been allocated, when base station device 1 receives data for relay station device 2 or a resource allocation request from relay station device 2. Communication T using reuse resources is classified according to the structural type and shielding ability (attenuation distance D) of shielded space 20 that accommodates communication terminal device 23. Communication R for which communication resources have already been allocated is classified according to devices involved in the communication. Reuse requirements are specified for each combination of classification of communication T according to structural type and shielding ability and classification of allocated communication R.

[0068] For each combination, the reuse requirement defines whether (yes) or not (no) the allocated communication resources of communication R can be reused as the communication resources r of communication T, separated into downlink communication from the base station apparatus 1 and uplink communication to the base station apparatus 1. The structural types for which reuse is not possible in any of the cases of R1, R2, and R3 are not described in the reuse table. For example, when the attenuation distance D of the vehicle is greater than b (b < D), since reuse is not possible in any of the cases of communication R being R1, R2, or R3, it is not recorded in the reuse table. The communication resources for which the possibility of reuse is considered are between downlink communications or between uplink communications.

[0069] The attenuation distance in the reuse table is the distance from the relay station apparatus 2 at which the intensity of the radio wave used for the downstream communication from the relay station apparatus 2 to the communication terminal apparatus 23 within the shielding space 20 attenuates to a predetermined value or less. The predetermined value can be set as appropriate, and examples include the ratio with respect to the radio wave intensity in the shielding space 20 (for example, half attenuation), the radio wave intensity, and the like. Here, the "predetermined value" includes not only a fixed value but also a value that changes depending on predetermined conditions.

[0070] Referring to FIG. 9(a), when the shielding space 20 provided with the relay station apparatus 2 of communication T using the reuse resource is a vehicle, it is explained whether the communication resources already allocated to the communication R1 between the relay station apparatus 2 and the base station apparatus 1 can be reused. In this case, the possibility of reusing the communication resources depends on the shielding ability of the shielding space 20 for both downlink and uplink communications. When the shielding ability of the shielding space 20 is greater than the predetermined value (T1), since the attenuation distance D is less than the predetermined value a, the reuse of the communication resources of communication R1 is possible. When the shielding ability of the shielding space 20 is equal to or less than the predetermined value (T2), since the attenuation distance D is equal to or greater than the predetermined value a, the reuse of the communication resources of communication R1 is not possible.

[0071] As shown in Fig. 9(b), even when the shielding space 20 in which the relay station device 2 of communication T is provided is a building, the availability of reusing the communication resources already allocated to the communication R1 between the relay station device 2 and the base station device 1 is similarly determined. That is, for both downlink and uplink communications, when the attenuation distance D is less than the predetermined value c (T3), the reuse of the communication resources of communication R1 is possible, and when the attenuation distance D is greater than the predetermined value c, the reuse of the communication resources of communication R1 is Not possible not possible.

[0072] With reference to Figs. 10(a) and 10(b), the availability of reuse when the shielding space 20A in which the relay station device 2A of communication T using the reused resources is provided is a vehicle will be described. In the examples shown in these figures, the communication R for which communication resources have been allocated is the communication R2 between the relay station device 2B provided in the vehicle and the base station device 1. The intensity when the radio wave of the uplink communication R2 from another relay station device 2B to the base station device 1 reaches the relay station device 2A varies depending on the positional relationship between the relay station device 2A and the relay station device 2B. Therefore, the availability of reusing communication R2 is determined using the predetermined distances Xa and Xb between the relay stations, which are defined according to the type of structure to which the shielding space 20A of the relay station device 2A belongs.

[0073] The distance Xa is defined as the distance at which the communication T between the relay station device 2A and the communication terminal device 23A and the communication R2 between the base station device 1 and another relay station device 2B do not interfere when the shielding space 20A belongs to the structure type T1. Also, the distance Xb is defined as the distance at which the communication T between the relay station device 2A and the communication terminal device 23A and the communication R2 between the base station device 1 and another relay station device 2B do not interfere when the shielding space 20A belongs to the structure type T2. For this reason, similar to the case where the predetermined value of the attenuation distance is a < b, the predetermined distance is also Xa < Xb.

[0074] As shown in Fig. 10(a), when the shielding space 20A of the relay station device 2A belongs to the structure type T1, when the distance L between the relay station device 2A and the relay station device 2B is greater than a predetermined distance Xa (L > Xa), the communication R2 and the communication T are less likely to interfere. Therefore, it is possible to reuse the communication resources already allocated to the communication R2 for the communication T. Similarly, when the shielding space 20A of the relay station device 2A belongs to the structure type T2, when the distance L is greater than a predetermined distance Xb (L > Xb), it is possible to reuse the communication resources already allocated to the communication R2 for the communication T.

[0075] As shown in Fig. 10(b), when the shielding space 20A of the relay station device 2A belongs to the structure type T1, when the distance L between the relay station device 2A and the relay station device 2B is less than or equal to a predetermined distance Xa (L ≤ Xa), the communication R2 and the communication T are likely to interfere. Therefore, it is not possible to reuse the communication resources already allocated to the communication R2 for the communication T. Similarly, when the shielding space 20A of the relay station device 2A belongs to the structure type T2, when the distance L is less than or equal to a predetermined distance Xb (L ≤ Xb), it is not possible to reuse the communication resources already allocated to the communication R2 for the communication T.

[0076] From the base station device 1 to another relay station device 2B Unlike the uplink communication R2, the radio wave intensity of the downlink communication R2 is not affected by the positional relationship between the relay station device 2A and the relay station device 2B. Therefore, as shown in the reuse table of Fig. 8, when the shielding space 20A of the relay station device 2A belongs to the structure type T1 (D < a), it is possible to reuse the communication resources already allocated to the communication R2 for the communication T, and in other cases (D ≥ a), reuse is not possible.

[0077] When the relay station device 2A is installed in a building, for the uplink communication, similar to the case where the relay station device 2A is installed in a vehicle, the availability of reuse is determined using a predetermined distance Xc defined as the distance at which the communication T and the communication R2 do not interfere. That is, when the shielding space 20A of the building belongs to the structure type T3 (D < c), when the distance L between the relay station device 2A and the relay station device 2B is greater than a predetermined distance Xc (L > Xc), it is possible to reuse the communication resources already allocated to the communication R2 for the communication T, and when the distance L is less than or equal to a predetermined distance Xc (L ≤ Xc), reuse is not possible. For downlink communication, when the shielding space 20A of the building belongs to the structure type T3 (D < c), the reuse of the communication resources already allocated to communication R2 for communication T is permitted; otherwise (D ≥ c), reuse is not permitted.

[0078] In FIGS. 8, 10(a) and 10(b), communication R2 is the communication between the base station device 1 and another relay station device 2B. However, the communication terminal device 23B may communicate directly with the base station device 1 without going through another relay station device 2B. In this case, the distance between the relay station device 2A and the communication terminal device 23B is compared with distance Xa or distance Xb to determine whether communication R2 can be reused.

[0079] Referring to FIGS. 11(a) and 11(b), the permissibility of reusing the communication resources already allocated to communication R3 for communication T will be described. Similar to communication (T), communication R3 is the communication between the relay station device 2B and the communication terminal device 23B accommodated therein. In this case, in addition to the shielding ability of the shielding space 20A where the relay station device 2A is provided, the shielding ability of the shielding space 20B where the relay station device 2B is provided also becomes an issue. Therefore, between the attenuation distance DA of the shielding space 20A and the attenuation distance DB of the shielding space 20B, the larger of the two, Max(a) and Max(b), is compared with the distance L between the relay station devices 2A and 2B to determine whether the communication resources can be reused.

[0080] As shown in FIG. 11(a), when the attenuation distance DB of the shielding space 20B where the relay station device 2B is provided is larger than the attenuation distance DA of the shielding space 20A where the relay station device 2A is provided, the distance L between the relay station device 2A and the relay station device 2B is compared with the attenuation distance DB. When the attenuation distance DA < a, the attenuation distance DB becomes Max(a); when a ≤ attenuation distance DA < b, the attenuation distance DB becomes Max(b). When the distance L is greater than the attenuation distance DB (L > Max(a), L > Max(a)), the reuse of the communication resources already allocated to communication R3 for communication T is permitted. When the distance L is less than or equal to the attenuation distance DB (L ≤ Max(a), L ≤ Max(b)), the reuse of the communication resources already allocated to communication R3 for communication T is not permitted.

[0081] When the shielded space 20 in which the relay station device 2 of the communication (T) is installed is a building, both the downstream and upstream are the same as the communication R1. 5. Summary The features of the device, method, and program in each embodiment of the present invention have been described above.

[0082] The terms used in each embodiment are merely examples and may be replaced with synonymous terms or terms having the same functions.

[0083] The block diagrams used to explain the embodiments classify and organize the configuration of the device by function. The blocks showing the respective functions are realized by any combination of hardware or software. In addition, since the block diagrams show the functions, they can also be understood as disclosures of a method invention and a program invention that realizes the method.

[0084] The order of the functional blocks that can be understood as the processes, flows, and methods described in each embodiment may be changed as long as there are no constraints such as a relationship in which one step utilizes the results of another step prior to it.

[0085] The terms first, second, through Nth (N is an integer) used in each embodiment and in the claims are used to distinguish two or more configurations or methods of the same type, and do not limit the order or superiority or inferiority.

[0086] Each embodiment is based on an apparatus mounted on a vehicle, but the present invention also includes dedicated or general-purpose apparatuses other than those for use in vehicles, unless otherwise limited by the claims.

[0087] In each embodiment, the device disclosed in each embodiment has been described on the assumption that it is mounted on a vehicle, but it may also be carried by a pedestrian.

[0088] Examples of the form of the device of the present invention are as follows. Examples of the component form include a semiconductor element, an electronic circuit, a module, and a microcomputer. Examples of semi-finished products include electronic control units (ECUs (Electric Control Units)) and system boards. Finished product forms include mobile phones, smartphones, tablets, personal computers (PCs), workstations, and servers. Other examples include devices with communication functions, such as video cameras, still cameras, and car navigation systems.

[0089] Furthermore, necessary functions such as an antenna and a communication interface may be added to each device.

[0090] It is envisioned that the device of the present invention will be used for the purpose of providing various services, and the device of the present invention will be used, the method of the present invention will be used, and / or the program of the present invention will be executed in conjunction with the provision of such services.

[0091] In addition, the present invention can be realized not only by dedicated hardware having the configuration and functions described in each embodiment, but also as a combination of a program for realizing the present invention recorded on a recording medium such as a memory or a hard disk, and general-purpose hardware having a dedicated or general-purpose CPU and memory capable of executing the program.

[0092] A program stored in a non-transient physical recording medium (for example, an external storage device (hard disk, USB memory, CD / BD, etc.) or an internal storage device (RAM, ROM, etc.)) of dedicated or general-purpose hardware can be provided to the dedicated or general-purpose hardware via a recording medium, or via a communication line from a server without using a recording medium. This makes it possible to always provide the latest functions through program upgrades. [Industrial Applicability]

[0093] The present invention is useful as a device that improves communication efficiency by reusing communication resources that are less likely to interfere among communication resources already allocated to communication between a relay station device mounted in a shielded space with known radio wave shielding ability of an automobile or building and a communication terminal device. [Explanation of symbols]

[0094] REFERENCE SIGNS LIST 1 base station device, 2 relay station device, 20 shielded space, 23 communication terminal device, 122 resource allocation unit, 123 reuse resource specification unit, 124 transmission instruction unit, 125 new resource allocation unit, 131 relay station information storage unit, 132 reuse requirement storage unit, 251 connection request instruction unit, 254 reuse resource acquisition unit, 255 reuse resource allocation unit, 256 transmission instruction unit, 261 relay station information storage unit

Claims

1. A base station device (1) that communicates with a communication terminal device (23) in a shielded space (20) via a relay station device (2) that can simultaneously perform downstream communication with the communication terminal device (23) in the shielded space (20) using a downstream antenna (22) provided in the shielded space, and upstream communication with the base station device using an upstream antenna (21) provided outside the shielded space, a resource allocation unit (122) for allocating communication resources used for communication between the relay station device and the base station device or communication between another relay station device and the base station device; a reuse requirement storage unit (132) that stores requirements for enabling reuse of the allocated resources, which are the communication resources allocated by the resource allocation unit, in the downstream communication between the relay station device and the communication terminal device, the reuse requirements being classified as to whether or not the reuse is possible based on a reference radio wave shielding ability of a reference radio wave shielding structure that constitutes a reference shielded space; A relay station information acquisition unit (121) that acquires the radio wave shielding ability of the radio wave shielding structure that constitutes the shielded space from the relay station device; A reuse resource specifying unit (123) that specifies, from among the allocated resources, a reuse resource that is a communication resource used for the downstream communication between the relay station device and the communication terminal device and that has a radio wave shielding capability that satisfies the reuse requirement; a transmission instruction unit (124) for instructing the relay station device to transmit the reused resource, Base station device (1).

2. The allocated resources are further communication resources allocated to communication between the other relay station device and another communication terminal device, or communication resources allocated to communication between the base station device and the other communication terminal device. The base station apparatus according to claim 1.

3. the reuse requirement storage unit stores, as the reuse requirement, an attenuation distance from the relay station device at which the radio wave intensity of the downstream communication attenuates to a predetermined value; The base station device according to claim 1 .

4. the reuse requirement storage unit stores, as the reuse requirement, an attenuation distance from the relay station device at which the radio wave intensity of the downstream communication attenuates to a predetermined value, and a distance between the relay station device and another relay station device corresponding to the attenuation distance. The base station device according to claim 1 .

5. A relay station device (2) which simultaneously performs downstream communication with a communication terminal device (23) in a shielded space (20) using a downstream antenna (22) provided in the shielded space, and upstream communication with a base station device (1) using an upstream antenna (21) provided outside the shielded space, and relays communication between the communication terminal device and the base station device, A relay station information storage unit (261) that stores the radio wave shielding ability of the radio wave shielding structure that constitutes the shielded space; A connection request instruction unit (251) that transmits the radio wave shielding capability to the base station device; a reuse resource acquisition unit (254) that acquires from the base station device a reuse resource, the reuse resource being identified from among allocated resources that are communication resources allocated to communication between the relay station device and the base station device or communication between another relay station device and the base station device, and whose radio wave shielding ability satisfies a reuse requirement; a reuse resource allocation unit (255) for allocating the reuse resources to communication between the relay station device and the communication terminal device, The reuse requirement is a requirement for the allocated resource to be reusable in the downstream communication between the relay station device and the communication terminal device, and the reusability is classified based on a reference radio wave shielding ability of a reference radio wave shielding structure that constitutes a reference shielded space. Relay station device (2).

6. A communication control method for a base station device that communicates with a communication terminal device via a relay station device that can simultaneously perform downstream communication with a communication terminal device in a shielded space using a downstream antenna provided in the shielded space, and upstream communication with a base station device using an upstream antenna provided outside the shielded space, comprising: Allocating communication resources to be used for communication between the relay station device and the base station device or for communication between another relay station device and the base station device (S104); storing reuse requirements that allow the allocated resources, which are the allocated communication resources, to be reused in the downstream communication between the relay station device and the communication terminal device, the reuse requirements being classified as to whether or not the reuse is possible based on a reference radio wave shielding ability of a reference radio wave shielding structure that constitutes a reference shielded space; The radio wave shielding ability of the radio wave shielding structure constituting the shielded space is acquired from the relay station device (S101); Identifying a reuse resource, which is a communication resource used for the downstream communication between the relay station device and the communication terminal device, from among the allocated resources, and the radio wave shielding capability satisfies the reuse requirement (S106); The reuse resource is transmitted from the base station device to the relay station device (S120); Communications control method.

7. A communication control program executed by a base station device that communicates with a communication terminal device via a relay station device that is mounted on the base station device and that can simultaneously perform downstream communication with a communication terminal device in a shielded space using a downstream antenna provided in the shielded space, and upstream communication with the base station device using an upstream antenna provided outside the shielded space, comprising: Allocating communication resources to be used for communication between the relay station device and the base station device or for communication between another relay station device and the base station device (S104); storing reuse requirements that allow the allocated resources, which are the allocated communication resources, to be reused in the downstream communication between the relay station device and the communication terminal device, the reuse requirements being classified as to whether or not the reuse is possible based on a reference radio wave shielding ability of a reference radio wave shielding structure that constitutes a reference shielded space; The radio wave shielding ability of the radio wave shielding structure constituting the shielded space is acquired from the relay station device (S101); Identifying a reuse resource, which is a communication resource used for the downstream communication between the relay station device and the communication terminal device, from among the allocated resources, and the radio wave shielding capability satisfies the reuse requirement (S106); The reuse resource is transmitted from the base station device to the relay station device (S120); Communications control program.

8. A communication control method for a relay station device that simultaneously performs downstream communication with a communication terminal device in a shielded space using a downstream antenna provided in the shielded space, and upstream communication with a base station device using an upstream antenna provided outside the shielded space, comprising: Transmitting the radio wave shielding capability of the radio wave shielding structure constituting the shielded space to the base station device (S202); Acquire from the base station device a reuse resource, the reuse resource being identified from among allocated resources that are communication resources allocated to communication between the relay station device and the base station device or communication between another relay station device and the base station device, and the radio wave shielding ability of the reuse resource satisfies a reuse requirement (S206); Allocating the reused resources to communication between the relay station device and the communication terminal device (S207); The reuse requirement is a requirement for the allocated resource to be reusable in the downstream communication between the relay station device and the communication terminal device, and the reusability is classified based on a reference radio wave shielding ability of a reference radio wave shielding structure that constitutes a reference shielded space. Communications control method.

9. A communication control program executed by a relay station device, the relay station device being mounted on the relay station device and simultaneously performing downstream communication with a communication terminal device in a shielded space using a downstream antenna provided in the shielded space, and upstream communication with a base station device using an upstream antenna provided outside the shielded space, the program comprising: Transmitting the radio wave shielding capability of the radio wave shielding structure constituting the shielded space to the base station device (S202); Acquire from the base station device a reuse resource, the reuse resource being identified from among allocated resources that are communication resources allocated to communication between the relay station device and the base station device or communication between another relay station device and the base station device, and the radio wave shielding ability of the reuse resource satisfies a reuse requirement (S206); Allocating the reused resources to communication between the relay station device and the communication terminal device (S207); The reuse requirement is a requirement for the allocated resource to be reusable in the downstream communication between the relay station device and the communication terminal device, and the reusability is classified based on a reference radio wave shielding ability of a reference radio wave shielding structure that constitutes a reference shielded space. Communications control program.

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