Wireless communication system, wireless communication method, and terminal device

Abstract

Provided is a wireless communication system comprising a plurality of terminal devices, and a base station device in a radio access network that communicates wirelessly with the plurality of terminal devices, wherein the plurality of terminal devices each comprise: a cost calculation unit that, by sharing observation information for communication cost calculation between a plurality of terminal devices belonging to a previously or dynamically set group, acquires observation information for communication cost calculation of another terminal device belonging to the group, and on the basis of the acquired observation information for communication cost calculation, and observation information of the device itself, calculates a communication cost; and a radio access network communication unit that, on the basis of the communication cost calculated by the cost calculation unit, determines whether to communicate with the base station device by an individual communication or cooperative communication method, and communicates with the base station device by the determined method.　

Description

Technical Field

[0001] The present invention relates to a wireless communication system, a wireless communication method, and a terminal device.

Background Art

[0002] In the development of RAN (Radio Access Network) systems, due to the pursuit of increased capacity and speed, and the shift to high frequency bands due to the shortage of frequency resources, a huge number of base stations need to be installed. As a result, the environmental burden caused by the energy consumption required by RAN equipment cannot be ignored. There is a need to study a network configuration method that contributes to power saving of the RAN infrastructure while maintaining user perceived quality such as coverage and throughput.

[0003] As one idea, instead of simply increasing the number of base stations to ensure coverage, it is conceivable to perform cooperative communication between terminal devices against the background of the spread of the number of terminal devices for users (see, for example, Non-Patent Document 1). In Non-Patent Document 1, improvement of coverage and throughput by relay transmission by terminal devices is proposed. It is expected that multiple terminal devices can obtain path diversity or gain through cooperative wireless transmission, and increase the communication performance compared to communication by a single terminal device.

Prior Art Documents

Non-Patent Documents

[0004]

Non-Patent Document 1

Non-Patent Document 2

[0005] However, from the perspective of reducing power consumption, increasing the number of cooperating terminals does not necessarily lead to improved transmission performance relative to energy consumption. It is necessary to select cooperating terminals considering the propagation environment and transmission capabilities of each terminal device. For example, Non-Patent Document 2 analyzes the effects of selecting cooperating terminals, but it does not mention the network configuration or specific means necessary for selecting cooperating terminals as a wireless communication system. It is also necessary to select cooperating terminals that take into account terminal devices with different capabilities and different states. Thus, conventionally, there has been a problem in that there is no means to select cooperating terminals with high transmission performance per unit of power consumption.

[0006] In view of the above circumstances, the present invention aims to provide a technology that enables the selection of cooperative terminals with high transmission performance per unit of power consumption. [Means for solving the problem]

[0007] One aspect of the present invention is a wireless communication system comprising a plurality of terminal devices and a base station device in a wireless access network that performs wireless communication between the plurality of terminal devices, wherein the plurality of terminal devices share observation information for calculating communication costs among the plurality of terminal devices belonging to a predetermined or dynamically set group, thereby acquiring observation information for calculating communication costs from other terminal devices belonging to the group, and calculating communication costs based on the acquired observation information for calculating communication costs and the observation information of the device itself, and a wireless access network communication unit that determines whether to communicate with the base station device by single communication or coordinated communication based on the communication costs calculated by the cost calculation unit, and performs communication with the base station device by the determined method.

[0008] One aspect of the present invention is a wireless communication method in a wireless communication system comprising a plurality of terminal devices and a base station device in a wireless access network that performs wireless communication between the plurality of terminal devices, wherein the plurality of terminal devices share observation information for calculating communication costs among the plurality of terminal devices belonging to a predetermined or dynamically set group, thereby acquiring the observation information for calculating communication costs from other terminal devices belonging to the group, calculating the communication cost based on the acquired observation information for calculating communication costs and the observation information of their own device, deciding whether to communicate with the base station device by single communication or coordinated communication based on the calculated communication cost, and communicating with the base station device by the determined method.

[0009] One aspect of the present invention is a terminal device comprising: a cost calculation unit that acquires observation information for calculating communication costs from other terminal devices belonging to a group that is set in advance or dynamically, by sharing observation information for calculating communication costs among a plurality of terminal devices belonging to the group, and calculates a communication cost based on the acquired observation information for calculating communication costs and the observation information of its own device; and a wireless access network communication unit that determines whether to communicate with a base station device in a wireless access network by single communication or coordinated communication based on the communication cost calculated by the cost calculation unit, and communicates with the base station device by the determined method. [Effects of the Invention]

[0010] This invention makes it possible to select cooperative terminals with high transmission performance per unit of power consumption. [Brief explanation of the drawing]

[0011] [Figure 1] This figure shows an example of the configuration of a wireless communication system in the first embodiment. [Figure 2] This figure shows an example of the configuration of a terminal device in the first embodiment. [Figure 3] This figure shows an example of the configuration of a RAN transmitter in the first embodiment. [Figure 4] This figure shows an example of the configuration of a RAN receiver in the first embodiment. [Figure 5] This is a flowchart showing the processing flow performed by the terminal device in the first embodiment. [Figure 6] This figure shows an example of the configuration of a wireless communication system in the second embodiment. [Figure 7] This figure shows an example of the configuration of a terminal device in the third embodiment. [Modes for carrying out the invention]

[0012] One embodiment of the present invention will be described below with reference to the drawings. (First embodiment) Figure 1 shows an example configuration of a wireless communication system 100 in the first embodiment. The wireless communication system 100 comprises a base station device 10 and a plurality of terminal devices 20. In Figure 1, the wireless communication system 100 is shown to have a configuration with four terminal devices 20-1 to 20-4, but the number of terminal devices 20 can be any number.

[0013] Base station equipment 10 is a base station device in the RAN. Wireless communication is performed between base station equipment 10 and multiple terminal devices 20, either through standalone communication or cooperative communication.

[0014] Multiple terminal devices 20 constitute a wireless PAN (Personal Area Network) network (NW(PAN) in Figure 1). A wireless PAN is a network composed of terminals located in close proximity and is a low-power network compared to a RAN. In the first embodiment, the case where the network configuration of the multiple terminal devices 20 constituting the wireless PAN is a mesh topology will be described. That is, the multiple terminal devices 20 form wireless PAN links between each terminal device 20, constituting a mesh wireless PAN network. In this way, in the first embodiment, since the multiple terminal devices 20 constitute a wireless PAN with a mesh topology, information is shared in a distributed manner.

[0015] Furthermore, in the first embodiment, the multiple terminal devices 20 constituting the wireless PAN are described as a pre-configured group. As a method for pre-configuring the multiple terminal devices 20 constituting the wireless PAN, the target of the PAN can register the MAC addresses for which it will accept connections in advance. For example, if there is a need to prevent others from using the battery, this can be prevented. Of course, other authentication methods may also be used.

[0016] A plurality of terminal devices 20 share observation information for communication cost calculation among the plurality of terminal devices 20 belonging to a group. The communication cost is an index indicating the performance of communication with respect to power consumption. Here, the observation information for communication cost calculation is information for calculating the communication cost related to the communication between the terminal device 20 and the base station device 10, and examples include information that can be obtained by a single terminal device 20, information on radio channel quality, and the like.

[0017] Information that can be obtained by a single terminal device 20 includes, for example, the remaining battery level, transmission capabilities (e.g., a link quality table such as the number of antennas, bandwidth, frequency band, transmission capacity per power consumption), the operating state of the terminal device 20 (e.g., whether it is in an active state or a sleep state), and the like. Information on radio channel quality includes communication performance in RAN communication between terminal devices 20 and 20, past throughput, communication success rate, channel quality indicator (CQI), and the like. Further, the observation information for communication cost calculation may include information such as an estimation from the observation information or position information such as GPS (Global Positioning System), and a determination result of the visibility state of RAN communication from a camera image or the like.

[0018] By sharing the observation information for communication cost calculation among the plurality of terminal devices 20 belonging to a group, the terminal device 20 obtains the observation information for communication cost calculation of other terminal devices 20 belonging to the group (hereinafter referred to as "other terminal observation information"), and calculates the communication cost based on the obtained other terminal observation information and the observation information of its own device. The terminal device 20 determines whether to communicate with the base station device 10 by either single communication or cooperative communication based on the communication cost, and communicates with the base station device 10 by the determined method.

[0019] FIG. 2 is a diagram showing a configuration example of the terminal device 20 in the first embodiment. The terminal device 20 includes a RAN communication unit 21, a PAN communication unit 22, a camera 23, a position information acquisition unit 24, a radio quality observation unit 25, a shielding state determination unit 26, a terminal state observation unit 27, and a cost calculation unit 28.

[0020] The RAN communication unit 21 is a wireless interface for RAN. The RAN communication unit 21 consists of a RAN antenna 211, a RAN receiver 212, a cooperative transmission control unit 213, and a RAN transmitter 214. The RAN communication unit 21 is one embodiment of a wireless access network communication unit.

[0021] The RAN antenna 211 receives radio waves transmitted from the base station device 10 or other terminal device 20, converts the received radio waves into electrical signals, and outputs them to the RAN receiver 212. The RAN antenna 211 converts the electrical signals output from the RAN transmitter 214 into radio waves and transmits them to the base station device 10.

[0022] The RAN receiver 212 acquires radio quality information based on the electrical signals output from the RAN antenna 211. For example, the RAN receiver 212 acquires radio quality information based on the electrical signals obtained through wireless communication with the base station equipment 10. For example, the RAN receiver 212 acquires radio quality information such as CQI, SINR (Signal to Interference Noise Ratio), throughput, and communication success rate.

[0023] The cooperative transmission control unit 213 determines whether to communicate with the base station device 10 using standalone communication or cooperative communication, based on the communication cost calculated by the cost calculation unit 28. The cooperative transmission control unit 213 controls the operation of the RAN transmitter 214 according to the determined communication method. For example, if the cooperative transmission control unit 213 decides to communicate with the base station device 10 using standalone communication, it requests the RAN transmitter 214 to perform the procedure to transmit the data to be transmitted on the transmission data buffer in the RAN transmitter 214. For example, if another terminal device 20 is the information source, the cooperative transmission control unit 213 waits for the data from the other terminal device 20 to be accumulated on the reception data buffer in the RAN receiver 212 before handing it over to the RAN transmitter 214.

[0024] The RAN transmitter 214 transmits the transmission data to the base station device 10 in accordance with the control of the cooperative transmission control unit 213.

[0025] The PAN communication unit 22 is a wireless interface for PAN. The PAN communication unit 22 consists of a PAN antenna 221, a PAN receiver 222, and a PAN transmitter 223.

[0026] The PAN antenna 221 receives radio waves transmitted from other terminal devices 20 (terminal devices 20 that constitute the PAN), converts the received radio waves into electrical signals, and outputs them to the PAN receiver 222. The PAN antenna 221 also converts the electrical signals output from the PAN transmitter 223 into radio waves and transmits them to other terminal devices 20.

[0027] Furthermore, if their frequency bands are close together, the RAN antenna 211 and the PAN antenna 221 may be used interchangeably.

[0028] Camera 23 generates image data by photographing the area around where the terminal device 20 is installed. The image data captures the area around where the terminal device 20 is installed. Camera 23 outputs the generated image data to the occlusion state determination unit 26.

[0029] The location information acquisition unit 24 acquires the location information of the terminal device 20. For example, the location information acquisition unit 24 acquires the location information using GPS. However, the location information acquisition unit 24 may acquire the location information of the terminal device 20 by other methods as long as it can acquire the location information of the terminal device 20.

[0030] The wireless quality observation unit 25 acquires wireless quality information obtained by the RAN receiver 212. The wireless quality observation unit 25 outputs the acquired wireless quality information to the shielding state determination unit 26 and the cost calculation unit 28.

[0031] The shielding state determination unit 26 determines whether the communication path between the camera 23 and the base station device 10 is line of sight or shielded, based on the image data output from the camera 23, the location information output from the location information acquisition unit 24, and the wireless quality information output from the wireless quality observation unit 25. The conditions for determining line of sight or shielding in the shielding state determination unit 26 are predetermined. The shielding state determination unit 26 outputs the determination result to the cost calculation unit 28.

[0032] For example, the shielding state determination unit 26 may determine that there is a shielding based on image data if there is a building blocking communication on the path from the device's location to the base station device 10, or it may determine that there is no line of sight if there is no building blocking communication on the path from the device's location to the base station device 10, or it may determine that there is a shielding even if there is no building blocking communication on the path from the device's location to the base station device 10, if the communication success rate is low. These determination conditions are just examples.

[0033] The terminal status observation unit 27 observes the status of its own device. For example, the terminal status observation unit 27 observes the battery level, transmission capacity, and operating status of the terminal device 20 as part of the status of its own device. The terminal status observation unit 27 outputs the observation results to the cost calculation unit 28.

[0034] The cost calculation unit 28 stores other terminal observation information output from the PAN communication unit 22, wireless quality information output from the wireless quality observation unit 25, judgment results output from the shielding state determination unit 26, and observation results output from the terminal state observation unit 27. The cost calculation unit 28 outputs the wireless quality information, judgment results, and observation results as its own terminal observation information to the PAN transmitter 223.

[0035] The sharing of observation information may be performed periodically, or it may be triggered by a sharing trigger when the terminal device 20 detects a change in observation information (for example, when the wireless quality observation unit 25 detects that the CQI fluctuation exceeds a threshold). The PAN configuration with a mesh topology excels at real-time sharing of observation information from other terminal devices 20 and offers high responsiveness to the RAN transmission / reception triggers of the device itself. Therefore, high efficiency can be expected when the number of cooperating terminals is small.

[0036] Furthermore, the cost calculation unit 28 calculates the communication cost based on the observation information of its own terminal and the observation information of other terminals. The cost calculation unit 28 outputs the calculated communication cost as cost information to the cooperative transmission control unit 213.

[0037] Figure 3 shows an example of the configuration of the RAN transmitter 214 in the first embodiment. The RAN transmitter 214 includes a data transfer unit 2141, a buffer 2142, a CRC encoder 2143, a channel encoder 2144, a modulator 2145, and an amplifier 2146.

[0038] The data transfer unit 2141 transfers the data to be transmitted, received from the cooperative transmission control unit 213, to the buffer 2142.

[0039] Buffer 2142 stores the data to be transmitted that has been transferred from the data transfer unit 2141.

[0040] The CRC encoder 2143 sequentially reads the data to be transmitted stored in the buffer 2142 and encodes it by adding an error detection code to the read data. The CRC encoder 2143 outputs the encoded data to be transmitted to the channel encoder 2144.

[0041] The channel encoder 2144 performs channel-specific encoding on the encoded data to be transmitted output from the CRC encoder 2143. The channel encoder 2144 outputs the encoded data to be transmitted to the modulator 2145.

[0042] The modulator 2145 modulates the encoded data to be transmitted output from the channel encoder 2144. The modulator 2145 outputs the modulated data to be transmitted to the amplifier 2146.

[0043] Amplifier 2146 amplifies the modulated data to be transmitted output from modulator 2145. Amplifier 2146 outputs the amplified data to be transmitted to RAN antenna 211.

[0044] Figure 4 shows an example of the configuration of the RAN receiver 212 in the first embodiment. The RAN receiver 212 includes an LNA 2121, a demodulator 2122, an MSE 2123, a channel decoder 2124, a CRC decoder 2125, a buffer 2126, and a data transfer unit 2127.

[0045] The LNA2121 is a low-noise amplifier that amplifies the electrical signal output from the RAN antenna 211. The LNA2121 outputs the amplified electrical signal to the demodulator 2122.

[0046] The demodulator 2122 demodulates the amplified electrical signal output from the LNA 2121. The demodulator 2122 outputs the demodulated electrical signal to the MSE 2123 and the channel decoder 2124. The demodulator 2122 acquires the CQI by demodulating the electrical signal. The demodulator 2122 outputs the acquired CQI information to the radio quality monitoring unit 25.

[0047] The MSE2123 calculates the mean square error of the demodulated electrical signal output from the demodulator 2122 and obtains the SINR based on the calculated mean square error. Specifically, the MSE2123 estimates the SINR from the mean square error (MSE) with respect to the nearest signal point obtained by the demodulator 2122. The MSE2123 outputs the acquired SINR information to the radio quality observation unit 25.

[0048] The channel decoder 2124 decodes the demodulated electrical signal output from the demodulator 2122 according to the channel. The channel decoder 2124 outputs the decoded electrical signal to the CRC decoder 2125.

[0049] The CRC decoder 2125 restores the data to be transmitted by performing error detection decoding on the decoded electrical signal output from the channel decoder 2124. The CRC decoder 2125 outputs the restored data to be transmitted to the buffer 2126. The CRC decoder 2125 outputs information on the communication success probability or throughput obtained from error detection during CRC (Cyclic Redundancy Check) decoding or channel decoding by the channel decoder 2124 to the wireless quality observation unit 25.

[0050] Buffer 2126 stores the data to be transmitted output from the CRC decoder 2125.

[0051] The data transfer unit 2127 transfers the data to be transmitted stored in the buffer 2126 to the cooperative transmission control unit 213 in response to a request from the cooperative transmission control unit 213.

[0052] Figure 5 is a flowchart showing the processing flow performed by the terminal device 20 in the first embodiment. The cost calculation unit 28 acquires its own terminal observation information (step S101). Specifically, the cost calculation unit 28 acquires wireless quality information output from the wireless quality observation unit 25, the judgment result output from the shielding state determination unit 26, and the observation result output from the terminal state observation unit 27. Furthermore, the cost calculation unit 28 acquires other terminal observation information received by the PAN communication unit 22 (step S102).

[0053] The cost calculation unit 28 calculates the communication cost based on the observation information of its own terminal and the observation information of other terminals (step S103). Specifically, if the observation information for the i-th terminal device 20 is defined as the required power consumption P(i) for throughput, the achieved throughput T(i) for SINR, the observed SINR as SINR(i), the battery remaining rate B(i), the shielding state as S(i) (for example, a step function of 1 for line of sight and 10 for shielding), and the usage flag f(i) (for example, a step function of 1 for use (active) and 100 for not use (sleep)), then, as an example, the cost function for each user regarding uplink transmission is defined as shown in equation (1) below.

[0054]

number

[0055] The cost calculation unit 28 then calculates the communication cost based on equation (1) above. The cost calculation unit 28 outputs the calculation result as cost information to the cooperative transmission control unit 213. The cooperative transmission control unit 213 determines whether or not to perform cooperative communication based on the cost information output from the cost calculation unit 28 (step S104). Specifically, the cooperative transmission control unit 213 first calculates, by pre-calculation, the combinations of terminal devices 20 for which F(i)=1 satisfies the following equation (2). This makes it possible to uniquely determine whether or not to perform terminal cooperative communication and the combination of terminal devices 20 for which cooperative communication will be performed.

[0056]

number

[0057] If the cooperative transmission control unit 213 determines that cooperative communication should be performed (step S104-YES), it selects a combination of terminal devices 20 to perform cooperative communication (step S105). For example, the cooperative transmission control unit 213 may select a combination of terminal devices 20 to perform cooperative communication based on equation (2) above. Alternatively, the cooperative transmission control unit 213 can select candidate combinations of terminal devices 20 such that F(i)=1 satisfies the following equation (3), and then select a combination that satisfies the following equation (4) so ​​that the battery levels of the terminal devices 20 performing cooperative communication are evenly distributed.

[0058]

number

[0059]

number

[0060] The cost function described above is merely an example and is not limiting. For example, the RAN downlink can be considered similarly, with only the various characteristics related to the observation information (P(i), T(i), etc.) changing. However, it is permissible that different terminal devices 20 may be selected as the target for coordination in the RAN uplink or downlink due to these differences in characteristics.

[0061] The cooperative transmission control unit 213 controls the establishment of RAN communication with the terminal device 20 to be cooperated with after the terminal device 20 to be cooperated with has been determined. There are two possible methods for establishing RAN communication with the terminal device 20 to be cooperated with, but are not limited to the methods shown below. The first method is to have the RAN communication unit 21 perform the formation of the RAN link with the terminal device 20 to be cooperated with. The second method is to have the PAN assist in the negotiation with the terminal device 20 to be cooperated with, leading to the formation of the RAN link with the terminal device 20 to be cooperated with. Specifically, it is conceivable to share information about the RAN information source (terminal device 20) and the destination station (terminal device 20) in advance via the PAN and then establish RAN communication with the terminal device 20 to be cooperated with. In the case of the second method, the cooperative transmission control unit 213 instructs the PAN communication unit 22 to share the RAN information.

[0062] The cooperative transmission control unit 213 controls the RAN transmitter 214 to transmit the data to be transmitted together with the terminal device 20 that performs cooperative communication (step S106).

[0063] In step S104, if the cooperative transmission control unit 213 determines that cooperative communication will not be performed (step S104-NO), it requests the RAN transmitter 214 to transmit the data to be transmitted from the transmission data buffer within the RAN transmitter 214. The RAN transmitter 214 transmits the data to be transmitted from the transmission data buffer to the base station device 10 in accordance with the request from the cooperative transmission control unit 213 (step S107).

[0064] The wireless communication system 100 configured as described above includes a cost calculation unit 28 that calculates communication costs based on the acquired observation information of other terminals and the own terminal observation information, by having multiple terminal devices 20 belonging to a predetermined group share observation information for calculating communication costs, and a RAN communication unit 21 that determines whether to communicate with the base station device 10 by single communication or coordinated communication based on the communication cost, and performs communication with the base station device 10 by the determined method. The terminal devices 20 select a combination of terminal devices 20 in which the sum of communication costs is the minimum or less than a threshold, and coordinate the selected combination of terminal devices 20 to perform wireless transmission with the base station device 10. Therefore, it becomes possible to select a coordinated terminal with high transmission performance per unit of power consumption.

[0065] (Second embodiment) In the second embodiment, we will describe the case where the network configuration of the multiple terminal devices constituting the wireless PAN is a star topology. Figure 6 shows an example configuration of the wireless communication system 100a in the second embodiment. The wireless communication system 100a comprises a base station device 10 and a plurality of terminal devices 20. In the wireless communication system 100a, the configuration of the terminal devices 20 and the operation based on cost calculation are the same as in the first embodiment. In the second embodiment, the case in which the network configuration of the plurality of terminal devices 20 constituting the wireless PAN is a star topology will be described. That is, the plurality of terminal devices 20 are divided into a master terminal device 20 and a slave terminal device 20 belonging to the master terminal device 20 on the PAN network topology, and constitute a star-topological wireless PAN. In this way, in the second embodiment, since the plurality of terminal devices 20 constitute a star-topological wireless PAN, information is shared in a centralized manner.

[0066] Furthermore, in the second embodiment, the multiple terminal devices 20 constituting the wireless PAN are described as being a pre-configured group. In the second embodiment, a master terminal device 20 (for example, terminal device 20-1) is predetermined, and the terminal devices 20 other than the master are simultaneously connected in a PAN with a star topology, where at least the master terminal device 20 is one vertex.

[0067] The master terminal device 20 centrally manages observation information from other terminals. Terminal devices 20 other than the master request observation information from the master terminal device 20 when needed. This allows terminal devices 20 other than the master to obtain observation information from other terminals. In the second embodiment, multiple terminal devices 20 share observation information for calculating communication costs among multiple terminal devices 20 belonging to a group using this method.

[0068] With the wireless communication system 100a configured as described above, the same effects as in the first embodiment can be obtained.

[0069] Furthermore, in the wireless communication system 100a, wireless links in the PAN are aggregated using a star-shaped network topology. Therefore, high efficiency can be expected when the number of terminal devices 20 is large.

[0070] (Third embodiment) In the first and second embodiments, the multiple terminal devices constituting the wireless PAN were a pre-configured group. In the third embodiment, a configuration in which the multiple terminal devices constituting the wireless PAN are dynamically changed will be described.

[0071] The system configuration in the third embodiment is the same as in the first or second embodiment. Therefore, in the third embodiment as well, the multiple terminal devices may constitute a wireless PAN in a mesh topology or a wireless PAN in a star topology.

[0072] In the third embodiment, at least one of the multiple terminal devices 20 has the authority to determine which terminal devices will participate in the wireless PAN. There may be multiple authorized terminal devices 20, and they are determined in advance or dynamically. The authorized terminal devices 20 decide whether to approve or deny connection requests from any terminal device requesting to join the wireless PAN. If approved by the authorized terminal device 20, the terminal device that sent the connection request to the wireless PAN can join the wireless PAN. On the other hand, if denied by the authorized terminal device 20, the terminal device that sent the connection request to the wireless PAN cannot join the wireless PAN.

[0073] Here, we will describe the overview of the wireless communication system in the third embodiment. Generally, PANs are expected to use less power and have a narrower communication range compared to RANs. Therefore, any terminal device requesting connection to a PAN adds location information obtained by GPS, etc., and information on the RAN base station beam index in beamtype communication, which is commonly used in high-frequency band RANs, to the observation information and provides it to the authorized terminal device 20.

[0074] The authorized terminal device 20 dynamically determines which terminal devices to join the group based on the location information included in the provided observation information (other terminal observation information) and the base station beam index, so that the positions of the terminal devices belonging to the group are close together. In this way, the authorized terminal device 20 dynamically determines that groups of nearby terminal devices 20 are aggregated into the PAN. The period for deciding whether to connect to the wireless PAN may be a provisional approval. In the PAN reception process, the authorized terminal device 20 obtains the other terminal observation information of the terminal device 20 that sent the connection request. Here, the PAN reception process is a process of negotiation that takes place between the authorized terminal device 20 and the terminal device 20 that sent the connection request via the PAN communication unit.

[0075] In the third embodiment, when multiple terminal devices 20 constitute a star-type wireless PAN, the master terminal device 20 and the authorized terminal device 20 may be different terminal devices 20, or they may be the same terminal device 20.

[0076] Figure 7 shows an example configuration of the terminal device 20b in the third embodiment. The terminal device 20b comprises a RAN communication unit 21, a PAN communication unit 22, a camera 23, a location information acquisition unit 24b, a wireless quality observation unit 25b, a shielding state determination unit 26, a terminal state observation unit 27, and a cost calculation unit 28b.

[0077] Terminal device 20b differs from terminal device 20 in that it includes a location information acquisition unit 24b, a wireless quality observation unit 25b, and a cost calculation unit 28b instead of the location information acquisition unit 24, wireless quality observation unit 25, and cost calculation unit 28. The other components of terminal device 20b are the same as those of terminal device 20. The differences will be explained below.

[0078] The location information acquisition unit 24b acquires the location information of the terminal device 20 (itself). The location information acquisition unit 24b outputs the acquired location information of the terminal device 20 to the shielding state determination unit 26 and the cost calculation unit 28b.

[0079] The wireless quality observation unit 25b acquires wireless quality information obtained by the RAN receiver 212. The wireless quality observation unit 25b outputs the acquired wireless quality information to the shielding state determination unit 26 and the cost calculation unit 28b. In addition to the wireless quality information shown in the first embodiment, the wireless quality information acquired by the wireless quality observation unit 25b also includes base station beam index information. The base station beam index information included in the wireless quality information represents the beam index with superior quality for transmission and reception of the terminal, among the beams provided by the base station equipment 10 to which the terminal belongs in RAN. For example, if the base station equipment 10 and the terminal equipment 20 have a transmit / receive dual relationship, it will be the beam index of the beam with the maximum received power.

[0080] The cost calculation unit 28b performs the same processing as in the first or second embodiment. Furthermore, if the cost calculation unit 28b is an authorized terminal device 20, it determines which terminal devices 20 will participate in the wireless PAN. Specifically, if there is a terminal device 20 that has newly requested to connect to the wireless PAN, the cost calculation unit 28b decides whether to approve or deny the request based on the location information included in the other terminal observation information obtained from the terminal device 20 that has newly requested to connect to the wireless PAN, and the base station beam index information. For example, the cost calculation unit 28b permits (approves) participation in the group if the condition that the locations of the terminal devices belonging to the group are close together is met. On the other hand, the cost calculation unit 28b denies (denies) participation in the group if the condition that the locations of the terminal devices belonging to the group are close together is not met. The conditions are assumed to be predetermined.

[0081] According to the wireless communication system 100 in the third embodiment configured as described above, the terminal devices 20 constituting the PAN can be dynamically changed. Furthermore, an authorized terminal device 20 dynamically determines the groups constituting the PAN so that adjacent groups of terminal devices 20 are aggregated into the PAN. In this way, the groups for sharing observation information are configured within a small range rather than a wide range. Therefore, information sharing becomes possible with low power consumption.

[0082] The terminal device 20 described above may be implemented using a computer. In that case, the program for implementing this function may be recorded on a computer-readable recording medium, and the program recorded on this recording medium may be loaded into a computer system and executed. Here, "computer system" includes hardware such as the OS and peripheral devices. Furthermore, "computer-readable recording medium" refers to portable media such as flexible disks, magneto-optical disks, ROMs, CD-ROMs, and storage devices such as hard disks built into a computer system.

[0083] Furthermore, "computer-readable recording media" may include those that dynamically hold programs for a short period of time, such as communication lines used when transmitting programs via networks such as the Internet or communication lines such as telephone lines, as well as those that hold programs for a certain period of time, such as volatile memory inside computer systems that act as servers or clients in such cases. In addition, the above-mentioned program may be for the purpose of realizing a part of the aforementioned functions, or it may be a program that can realize the aforementioned functions in combination with a program already recorded in the computer system, or it may be implemented using a programmable logic device such as an FPGA (Field Programmable Gate Array).

[0084] Although embodiments of this invention have been described in detail above with reference to the drawings, the specific configuration is not limited to these embodiments and includes designs and the like that do not depart from the spirit of this invention. [Industrial applicability]

[0085] This invention can be applied to wireless access networks. [Explanation of symbols]

[0086] 10…Base station equipment, 20, 20-1~20-4…Terminal equipment, 21…RAN communication unit, 22…PAN communication unit, 23…Camera, 24…Location information acquisition unit, 25…Wireless quality observation unit, 26…Shielding state determination unit, 27…Terminal state observation unit, 28…Cost calculation unit, 100, 100a…Wireless communication system, 211…RAN antenna, 212…RAN receiver, 213…Cooperative transmission control unit, 214…RAN transmitter, 221…PAN antenna, 222…PAN receiver, 223…PAN transmitter, 2121…LNA, 2122…Demodulator, 2123…MSE, 2124…Channel decoder, 2125…CRC decoder, 2126…Buffer, 2127…Data transfer unit, 2141…Data transfer unit, 2142...Buffer, 2143...CRC encoder, 2144...Channel encoder, 2145...Modulator, 2146...Amplifier

Claims

1. A wireless communication system comprising a plurality of terminal devices and a base station device in a wireless access network that performs wireless communication between the plurality of terminal devices, The aforementioned multiple terminal devices are, A cost calculation unit that calculates the communication cost by sharing observation information for communication cost calculation among multiple terminal devices belonging to a pre-configured or dynamically set group, thereby acquiring observation information for communication cost calculation from other terminal devices belonging to the group, and based on the acquired observation information for communication cost calculation and the observation information of its own device, A wireless access network communication unit determines whether to communicate with the base station device using either standalone communication, in which the data source terminal device and the base station device communicate directly, or cooperative communication, in which the data source terminal device and other terminal devices transmit the data together, based on the communication cost calculated by the cost calculation unit, and then communicates with the base station device using the determined method. Equipped with, At least one of the aforementioned multiple terminal devices has the authority to determine which terminal devices will join the group. A wireless communication system in which at least one authorized terminal device dynamically determines which terminal devices to join the group based on location information aggregated from each terminal device and the base station beam index for the wireless access network, such that the locations of the terminal devices belonging to the group are close together.

2. The cost calculation unit acquires one or more of the following as observation information: battery level, shielding status, transmission capacity, channel quality index, operating status, past throughput, communication success rate, location information, or line-of-sight status. The wireless communication system according to claim 1.

3. The aforementioned multiple terminal devices constitute a low-power personal area network, distinct from the wireless access network, as a group for sharing the observation information. The wireless communication system according to claim 1.

4. The aforementioned plurality of terminal devices constitute the personal area network in a mesh topology. The wireless communication system according to claim 3.

5. The plurality of terminal devices constitute the personal area network in a star topology, with one terminal device designated as the master and the master terminal device being at least one vertex. The wireless communication system according to claim 3.

6. A wireless communication method in a wireless communication system comprising a plurality of terminal devices and a base station device in a wireless access network that performs wireless communication between the plurality of terminal devices, The aforementioned multiple terminal devices By sharing observation information for calculating communication costs among the multiple terminal devices belonging to a pre-configured or dynamically set group, observation information for calculating communication costs from other terminal devices belonging to the group is obtained. Based on the acquired observation information for calculating communication costs and the observation information of the device itself, the communication cost is calculated. Based on the calculated communication cost, it is determined whether to communicate with the base station device using either standalone communication, in which the data source terminal device and the base station device communicate directly, or cooperative communication, in which the data source terminal device and other terminal devices transmit the data together. The determined method is used to communicate with the base station device. At least one of the aforementioned multiple terminal devices has the authority to determine which terminal devices will join the group. The authorized terminal device dynamically determines which terminal devices to join the group based on location information aggregated from each terminal device and the base station beam index for the wireless access network, such that the locations of the terminal devices belonging to the group are close together. Wireless communication method.

7. A cost calculation unit that calculates communication costs by sharing observation information for communication cost calculation among multiple terminal devices belonging to a pre-configured or dynamically set group, thereby acquiring the observation information for communication cost calculation from other terminal devices belonging to the group, and calculating the communication cost based on the acquired observation information for communication cost calculation and the observation information of its own device. Based on the communication cost calculated by the cost calculation unit, the wireless access network communication unit determines whether to communicate with the base station equipment in the wireless access network using either standalone communication, in which the data source terminal equipment and the base station equipment communicate directly, or cooperative communication, in which the data source terminal equipment and other terminal equipment transmit the data together, and then communicates with the base station equipment using the determined method. Equipped with, Having the authority to determine which terminal devices will participate in the aforementioned group, A terminal device that dynamically determines which terminal devices to join the group, based on location information aggregated from each terminal device and the base station beam index for the wireless access network, such that the locations of the terminal devices belonging to the group are close together.

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