JP4413254B2 - COMMUNICATION METHOD AND TERMINAL DEVICE USING THE SAME - Google Patents

Description

  The present invention relates to a communication technique, and more particularly to a communication method in an ad hoc network and a terminal device using the same.

  An ad hoc network is a self-supporting and distributed network that includes a terminal device as a component without depending on a base station device or a wired network. In an ad hoc network, terminal devices are equal to each other, and information exchange is performed by executing multihop. Such an ad hoc network routing method includes a table driving method, an on-demand method, and a hybrid method. In the table driving method, each terminal device maintains a routing table in which the destination of the packet signal is associated with the next hop destination. Each terminal device determines the next hop destination from the destination of the packet signal while referring to the routing table. Note that the routing table is periodically updated by a control packet signal. Examples of table driving methods are DSDV (Destination Sequence Distance Vector), WRP (Wireless Routing Protocol), CGSR (Clusterhead Gateway Switch Routing), and OLSR (Optimized Linking Route).

  In the on-demand method, a terminal device that is a source of information discovers a route to a destination when requesting transfer of a packet signal. First, the terminal device of the information source learns the reverse route to the terminal device of the information generation source by transferring the packet signal for inquiry by the flooding method, and the packet signal for inquiry The destination terminal device that received the message also responds. Based on the route thus discovered, the packet signal is transferred from the source terminal device to the destination terminal device. Examples of the on-demand method are AODV (Ad hoc On demand Distance Vector), DSR (Dynamic Source Measured Routing Algorithm, RDAR (Temporarily Ordered Routed Algorithm) Routing). The hybrid method is a method in which a table driving method and an on-demand method are combined (for example, see Non-Patent Document 1).

In addition, in an ad hoc network, a technique for simplifying setting of a terminal device has been proposed. The predetermined terminal device holds communication setting information, and a tag is placed in the immediate vicinity of the IC card reader / writer mounted on the terminal device. As a result, the IC card reader / writer transmits communication setting information by executing non-contact communication with the tag. Also, communication setting information is transmitted to another terminal device by executing a procedure opposite to that described above between the tag and the IC card reader / writer mounted on the other terminal device (for example, Patent Document 1).
Kenichi Mase, Keisuke Nakano, Masakazu Sengoku, Shoji Shinoda, “Ad Hoc Network”, Journal of the Institute of Electronics, Information and Communication Engineers, Japan, February 2001, 84, 2, p. 127-134 JP 2004-7351 A

  Considering the convenience of the user, it is desirable that the procedure for connecting the terminal device to the ad hoc network is easy. On the other hand, since the ad hoc network is formed by a plurality of terminal devices, security measures are required in consideration of the influence on other terminal devices. In order to improve security, a role that should approve the participation of a new terminal device in the ad hoc network is assigned to one of a plurality of terminal devices forming the ad hoc network (hereinafter referred to as the relevant device). A terminal device to which a role is assigned is called a “registration organization”). In order to improve the ease of the connection procedure, the connection procedure is performed by pressing the button provided in the new terminal device within a predetermined period after the button provided in the registration authority is pressed down. It is executed when

  Under such circumstances, the present inventor has come to recognize the following problems. When a plurality of new terminal devices request connection, the registration organization can cope with the above situation by executing connection processing (hereinafter referred to as “direct connection”) sequentially for each terminal device. However, direct connection may not be preferable depending on the number of new terminal devices or the state of the ad hoc network. For example, as the number of the plurality of new terminal devices increases, the period until the connection is completed becomes longer and the convenience for the user is impaired.

  The present invention has been made in view of such circumstances, and an object thereof is to provide a communication technique for executing connection of terminal devices suitable for the number of new terminal devices or the state of an ad hoc network.

  In order to solve the above problems, a terminal device according to an aspect of the present invention includes a communication unit that performs communication while forming an ad hoc network with another terminal device, and an ad hoc network formed in the communication unit. When a role that should approve participation of a new terminal device is assigned, a reception unit that receives a participation request from the new terminal device via the communication unit, and an approval for the participation request received by the reception unit A processing unit that executes processing and a notification unit that notifies a result of the approval processing executed in the processing unit. When the accepting unit receives a participation request from a plurality of new terminal devices, the processing unit forms another ad hoc network between the plurality of new terminal devices and executes an approval process for the other ad hoc network. .

  Another aspect of the present invention is also a terminal device. While this device forms an ad hoc network with other terminal devices, it has a role to approve the participation of a new terminal device to the communication unit that performs communication and the ad hoc network formed in the communication unit. If assigned, a reception unit that receives a participation request from a new terminal device via the communication unit, a processing unit that executes an approval process for the participation request received in the reception unit, and an approval executed in the processing unit A notification unit for notifying a result of the processing. When the receiving unit accepts a participation request from a plurality of new terminal devices, the processing unit forms another ad hoc network for a part of the plurality of new terminal devices, and then forms another ad hoc network. Approval processing is executed for the, and direct approval processing is executed for the rest.

  Yet another embodiment of the present invention is also a terminal device. While this device forms an ad hoc network with other terminal devices, it has a role to approve the participation of a new terminal device to the communication unit that performs communication and the ad hoc network formed in the communication unit. If assigned, a reception unit that receives a participation request from a new terminal device via the communication unit, a processing unit that executes an approval process for the participation request received in the reception unit, and an approval executed in the processing unit A notification unit for notifying a result of the processing. When the accepting unit receives a participation request from a plurality of new terminal devices, the processing unit forms another ad hoc network between the plurality of new terminal devices and executes an approval process for the other ad hoc network. Either the first process or a second process for executing a direct approval process for each of the plurality of new terminal devices is executed.

  Yet another embodiment of the present invention is a communication method. This method includes a step of performing communication while forming an ad hoc network with another terminal device, and a role that should approve participation of a new terminal device in the ad hoc network is assigned a new one. Receiving a participation request from the terminal device; and executing an approval process for the accepted participation request. The step of executing the approval process is to form a separate ad hoc network between a plurality of new terminal devices when a request for participation from a plurality of new terminal devices is received, and execute the approval process for another ad hoc network. To do.

  Yet another embodiment of the present invention is also a communication method. This method includes a step of performing communication while forming an ad hoc network with another terminal device, and a role that should approve participation of a new terminal device in the ad hoc network is assigned a new one. Receiving a participation request from the terminal device; and executing an approval process for the accepted participation request. In the step of executing the approval process, when a participation request from a plurality of new terminal devices is received, another ad hoc network is formed for a part of the plurality of new terminal devices, and then another ad hoc network is formed. Execute the approval process for the network and execute the direct approval process for the rest.

  Yet another embodiment of the present invention is also a communication method. This method includes a step of performing communication while forming an ad hoc network with another terminal device, and a role that should approve participation of a new terminal device in the ad hoc network is assigned a new one. Receiving a participation request from the terminal device; and executing an approval process for the accepted participation request. The step of executing the approval process is to form a separate ad hoc network between a plurality of new terminal devices when a request for participation from a plurality of new terminal devices is received, and execute the approval process for another ad hoc network. One of the first process to be executed and the second process to execute the direct approval process for each of the plurality of new terminal devices is executed.

  It should be noted that any combination of the above-described constituent elements and a conversion of the expression of the present invention between a method, an apparatus, a system, a recording medium, a computer program, etc. are also effective as an aspect of the present invention.

  ADVANTAGE OF THE INVENTION According to this invention, the connection of the terminal device suitable for the number of several new terminal devices or the state of an ad hoc network can be performed.

  Before describing the present invention in detail, an outline will be described. Embodiments described herein relate generally to a communication system that executes an ad hoc network formed by a plurality of terminal devices. In the ad hoc network, any one of a plurality of terminal devices is set as the above-described registration organization. In addition, there are a plurality of new terminal devices that wish to connect to the ad hoc network. When the registration authority directly connects to each of a plurality of new terminal devices, it takes a long time to complete the approval process for all of the plurality of new terminal devices. Therefore, the communication system according to the embodiment of the present invention executes the following process.

  The registration authority calculates the number of new terminal devices that wish to connect to the ad hoc network, and compares the calculation result with a threshold value. If the calculation result is smaller than the threshold value, the registration authority directly connects to each of the plurality of new terminal devices as described above. On the other hand, if the calculation result is equal to or greater than the threshold value, the registration authority instructs a plurality of new terminal devices to form another ad hoc network and collects approval processing for the formed ad hoc network. Execute. Here, such processing is referred to as “group connection”. In order to form another ad hoc network at an early stage, the registration organization divides another ad hoc network into a plurality of groups, and instructs each terminal device which group should be included. The terminal device forms a group according to the instruction. Here, the group corresponds to a small ad hoc network. Also, the registration authority finally forms another ad hoc network by transmitting an instruction to join the groups in stages.

  The communication system mainly includes (1) a process for connecting a new terminal device to an ad hoc network (hereinafter referred to as “connection process”), and (2) a routing table generation process in the ad hoc network (hereinafter referred to as “generation process”). ), (3) Data signal transfer processing (hereinafter referred to as “transfer processing”) in the ad hoc network based on the routing table is executed. The above-described approval process is included in the connection process (1).

  FIG. 1 shows a configuration of a communication system 100 according to an embodiment of the present invention. The communication system 100 includes a first terminal device 10a, a second terminal device 10b, a third terminal device 10c, a fourth terminal device 10d, a fifth terminal device 10e, a sixth terminal device 10f, The terminal device 10g is included. In addition, the Nth terminal device 10 n is about to be included in the communication system 100.

  The plurality of terminal devices 10, for example, the first terminal device 10a to the seventh terminal device 10g execute communication by forming an ad hoc network. Note that the terminal device 10 configuring the ad hoc network is not limited to the first terminal device 10a to the seventh terminal device 10g. Further, the plurality of terminal devices 10 correspond to, for example, a wireless LAN system compliant with a standard such as IEEE 802.11. In addition, as described above, the routing method in the ad hoc network only needs to correspond to a known technology such as a table driving method, an on-demand method, and a hybrid method. For example, in the case of a table driving method, The routing table is updated.

  One of the plurality of terminal devices 10, for example, the third terminal device 10c is assigned a role to approve the participation of the new terminal device 10 in the ad hoc network in addition to the communication function in the normal ad hoc network. It has been. That is, the third terminal device 10c corresponds to the aforementioned registration organization. Here, although the processing at the registration authority will be described later, the registration authority can be said to be a component having the authority to issue or cancel the admission qualification to the ad hoc network. Further, although the function of the registration organization is provided in the terminal device 10 other than the third terminal device 10c, it is assumed that it is suspended at present. Here, for the sake of clarity, it is assumed that the communication system 100 includes one registration authority.

  The new terminal device 10, that is, the Nth terminal device 10 n requests participation in the ad hoc network formed by the plurality of terminal devices 10. Here, the N-th terminal device 10n requests the registration organization to participate, and becomes a constituent element of the communication system 100 when participation is permitted by the registration organization. In the following description, for convenience, the Nth terminal apparatus 10n may be referred to as “requesting side” and the registration authority may be referred to as “response side”.

  FIG. 2 shows the configuration of the terminal device 10. The terminal device 10 includes a wireless unit 12, a modem unit 14, a processing unit 16, a control unit 18, a storage unit 20, an operation unit 22, a monitor 24, and a speaker 26. FIG. 1 shows a plurality of terminal devices 10 and further shows terminal devices 10 corresponding to the request side and the response side, but all the terminal devices 10 are as shown in FIG. It has a configuration.

  The radio unit 12 performs communication while forming an ad hoc network with another terminal device 10. As a reception process, the radio unit 12 performs frequency conversion on a radio frequency signal received via an antenna to generate a baseband signal. Further, the radio unit 12 outputs a baseband signal to the modem unit 14. In general, baseband signals are formed by in-phase and quadrature components, so two signal lines should be shown, but only one signal line is shown here for clarity. Shall. The wireless unit 12 also includes an LNA (Low Noise Amplifier), a mixer, an AGC, and an A / D conversion unit.

  As a transmission process, the radio unit 12 performs frequency conversion on the baseband signal input from the modem unit 14 to generate a radio frequency signal. Further, the radio unit 12 transmits a radio frequency signal from the antenna. The wireless unit 12 also includes a PA (Power Amplifier), a mixer, and a D / A conversion unit.

  The modem unit 14 demodulates the baseband signal from the radio unit 12 as a reception process. Further, the modem unit 14 outputs the demodulated result to the processing unit 16. Further, the modem unit 14 performs modulation on the signal from the processing unit 16 as transmission processing. Further, the modem unit 14 outputs the modulated result to the radio unit 12 as a baseband signal. When the terminal apparatus 10 supports an OFDM modulation scheme such as the IEEE802.11a standard, the modem unit 14 also executes FFT as a reception process and IFFT as a transmission process. When the terminal apparatus 10 supports a spread spectrum method such as the IEEE 802.11b standard, the modem unit 14 also performs despreading as a reception process and also performs spreading as a transmission process. Further, when the terminal apparatus 10 supports a MIMO scheme such as IEEE802.11n, the modem unit 14 also performs adaptive array signal processing as reception processing, and also performs distribution processing into a plurality of streams as transmission processing.

  The processing unit 16 performs digital signal processing on the signal from the modem unit 14 and the signal to the modem unit 14. Here, an example of digital signal processing is encoding of error correction as transmission processing and decoding of error correction as reception processing. The digital signal processing is not limited to this. Further, the processing unit 16 outputs the result of executing digital signal processing on the signal from the modem unit 14 to the control unit 18, and inputs the signal that is the source of the signal to the modem unit 14 from the control unit 18.

  The control unit 18 controls the operation of the entire terminal device 10. The processing executed by the control unit 18 is mainly classified into (4) data input / output processing in addition to the aforementioned (1) connection processing, (2) generation processing, and (3) transfer processing. Here, for convenience of explanation, explanation will be given in the order of (4), (2), (3), and finally (1) will be explained. First, (4) data input / output processing will be described. As an output process, the control unit 18 receives the result of the digital signal processing from the processing unit 16 and outputs the result to the monitor 24 and the speaker 26. In addition, as an input process, the control unit 18 receives an instruction signal from the operation unit 22 and outputs data corresponding to the instruction signal to the processing unit 16. Here, the operation unit 22 includes buttons and the like. Further, when the terminal device 10 is formed so as to be connected to a personal computer, the operation unit 22 may be a keyboard and a mouse provided in the personal computer.

  Next, (2) generation processing will be described. As described above, a known technique may be used to generate the routing table, but the control unit 18 stores the generated routing table in the storage unit 20. FIG. 3 shows the data structure of the routing table stored in the storage unit 20. As shown in the figure, a destination address column 30, a hop destination address column 32, and a hop number column 34 are included. Also, information other than these may be included. Here, in the destination address column 30 and the hop destination address column 32, the addresses are indicated as “A1”, “B1”, etc., but actually, for example, indicated by an IP address or the like. The same applies to the number of hops in the hop number column 34. Returning to FIG.

  Next, (3) transfer processing will be described. As described above, a known technique may be used for the transfer process. The control unit 18 acquires the destination address of the packet signal received from the wireless unit 12 via the processing unit 16. Further, referring to the routing table stored in the storage unit 20, the control unit 18 specifies a hop destination address corresponding to the acquired destination address. Further, the control unit 18 transmits a packet signal from the processing unit 16 via the wireless unit 12 to the identified hop destination address.

  Next, (1) connection processing will be described. The connection process is executed between the request-side terminal device 10 and the response-side terminal device 10, and here, after explaining the processing of the control unit 18 in the request-side terminal device 10, the response-side terminal device Processing of the control unit 18 in the apparatus 10 will be described. The request-side terminal device 10 corresponds to the Nth terminal device 10n in FIG. 1, and the response-side terminal device 10 corresponds to the third terminal device 10c in FIG.

  When the control unit 18 in the requesting terminal device 10 detects that the button on the operation unit 22 has been depressed by the user, the control unit 18 enters the request mode. When in the request mode, the control unit 18 wirelessly transmits from the processing unit 16 to the registration authority so as to transmit a packet signal indicating a request for participation in the ad hoc network (hereinafter referred to as “request signal”). The unit 12 is controlled. Thereafter, the processing unit 16 from the wireless unit 12 receives a packet signal indicating permission to participate (hereinafter referred to as “permission signal”) from the registration authority that has transmitted the request signal. The permission signal is input to the control unit 18. As a result, the control unit 18 enters a communication mode. In the communication mode, the control unit 18 controls the wireless unit 12 to the processing unit 16 to perform communication by participating in the ad hoc network.

  When the control unit 18 in the terminal device 10 on the responding side detects that a predetermined button on the operation unit 22 is pushed down by the user, the control unit 18 enters the approval mode. The approval mode is a state in which the approval process can be executed. In the approval mode, the control unit 18 receives a request signal from the requesting terminal device 10 over a predetermined period from the wireless unit 12 through the processing unit 16. The control unit 18 executes an approval process for the received request signal. Here, a known technique may be used for the approval process. For example, after exchanging the public key with the requesting terminal device 10 from the wireless unit 12 via the processing unit 16, the control unit 18 executes authentication processing and identification processing for the requesting terminal device 10. Here, the “device password” may be used for the authentication process.

  When the control unit 18 permits the participation, the control unit 18 transmits a permission signal from the processing unit 16 to the requesting terminal device 10 via the wireless unit 12. On the other hand, when the control unit 18 rejects the participation, the control unit 18 transmits a rejection signal from the processing unit 16 to the requesting terminal device 10 via the wireless unit 12. After a certain period of time, the control unit 18 enters the communication mode. In the communication mode, the control unit 18 controls the wireless unit 12 to the processing unit 16 to perform communication by participating in the ad hoc network.

  This configuration can be realized in terms of hardware by a CPU, memory, or other LSI of any computer, and in terms of software, it is realized by a program having a communication function loaded in the memory. Describes functional blocks realized by collaboration. Accordingly, those skilled in the art will understand that these functional blocks can be realized in various forms by hardware only, software only, or a combination thereof.

  The operation of the communication system 100 configured as above will be described. FIG. 4 is a sequence diagram showing a connection procedure in the communication system 100. The button of the Nth terminal device 10n is pushed down (S10), and the button of the third terminal device 10c is also pushed down (S12). The Nth terminal apparatus 10n transmits a request signal to the third terminal apparatus 10c (S14). The third terminal device 10c executes an approval process for the Nth terminal device 10n (S16). The third terminal apparatus 10c transmits a permission signal to the Nth terminal apparatus 10n (S18). Further, the third terminal apparatus 10c updates the routing table (S20).

  Below, the structure of the communication system which expanded the communication system 100 is demonstrated. Here, it is assumed that there are a plurality of requesting terminal devices 10. The responding terminal device 10 may execute the connection processing described so far for each of the plurality of requesting terminal devices 10. That is, the terminal device 10 on the response side may execute the above-described direct connection. However, in order to reduce the lengthening of connection processing due to an increase in the number of requesting terminal apparatuses 10, the responding terminal apparatus 10 determines the number of request signals within a predetermined period, that is, the requesting terminal apparatus 10 Direct connection or group connection is selected according to the number of connections. For example, if the request-side terminal device 10 is smaller than the threshold value, the connection processing will not be prolonged even if one device is connected to each other, and the response-side terminal device 10 executes direct connection. On the other hand, if the terminal device 10 on the request side becomes equal to or greater than the threshold value, the terminal device 10 on the response side executes group connection.

  The configuration of the terminal device 10 here is the same as the type shown in FIG. When the responding terminal device 10 enters the approval mode, as described above, the control unit 18 receives a request signal from the requesting terminal device 10 over a predetermined period. Here, it is assumed that there are a plurality of requesting terminal devices 10 and each is in the request mode. Therefore, the control unit 18 receives a plurality of request signals in a predetermined period. Further, the control unit 18 calculates the number of received request signals. Since the request signal includes information for identifying the requesting terminal device 10 that is the transmission source, the control unit 18 duplicates the request signal from the same requesting terminal device 10. Do not calculate. That is, the control unit 18 calculates the number of terminal devices 10 on the request side. The control unit 18 selects execution of direct connection or execution of group connection based on the calculation result while referring to the threshold value stored in the storage unit 20.

  FIG. 5 shows a data structure of threshold values stored in the storage unit 20. As shown in the figure, a number column 200 and a connection procedure column 202 are included. The control unit 18 compares the calculation result with the threshold “A”. The control unit 18 selects direct connection if the calculation result is smaller than A, and selects group connection if the calculation result is A or more. When the direct connection is selected, the control unit 18 sequentially executes the above-described approval processes one by one for each of the plurality of requesting terminal devices 10. The radio unit 12 has already measured the received power of the request signal, for example, the SNR and CNR, and the control unit 18 executes the approval process with priority from the requesting terminal device 10 having a high received power. As the received power increases, the probability of failure of the approval process for the requesting terminal device 10 is reduced, so that the number of requesting terminal devices 10 that have completed connection can be increased early. Note that the threshold value “A” may be determined in advance based on experiments and simulations.

  On the other hand, when the group connection is selected, the control unit 18 forms another ad hoc network among the plurality of requesting terminal devices 10. Here, for example, the control unit 18 forms a group in the two requesting terminal devices 10. When a plurality of such groups are formed, the control unit 18 next connects the groups. The control unit 18 expands the group so that the number of requesting terminal devices 10 gradually increases by sequentially repeating the connection of such groups, and finally forms another ad hoc network. Let The procedure from the formation of a group to the formation of another ad hoc network is notified from the terminal device 10 on the response side to the terminal device 10 on the request side, and details will be described later. Moreover, the control part 18 approves the several terminal device 10 of a request | requirement collectively by approving another ad hoc network. Here, when forming a group, the control unit 18 makes a pair of the terminal device 10 on the request side with high reception power and the terminal device 10 with low reception power based on the reception power of each request signal. .

  6A to 6D show an outline of a connection procedure in the communication system 100 of FIG. Here, a group connection procedure is particularly shown. In FIG. 6A, the (N + 1) th terminal device 10n + 1 to the (N + 4) th terminal device 10n + 4 correspond to the requesting terminal device 10, and the third terminal device 10c corresponds to the responding terminal device 10. Further, although the communication system 100 includes a plurality of terminal devices 10, the description is omitted here for the sake of clarity. The (N + 1) th terminal device 10n + 1 to the (N + 4) th terminal device 10n + 4 are in the request mode, and the third terminal device 10c is in the approval mode. Under such circumstances, the (N + 1) th terminal device 10n + 1 to the (N + 4) th terminal device 10n + 4 transmit a request signal. The third terminal apparatus 10c determines execution of group connection and also determines a procedure from formation of a group to formation of another ad hoc network. The third terminal apparatus 10c notifies the procedure from the (N + 1) th terminal apparatus 10n + 1 to the (N + 4) th terminal apparatus 10n + 4 as an instruction signal.

  FIG. 7 shows the data structure of the instruction signal generated by the control unit 18. As shown, a step column 210 and a connection column 212 are included. First, in step 1, the connection between the (N + 1) th terminal device 10n + 1 and the (N + 2) th terminal device 10n + 2 is instructed, and the connection between the (N + 3) th terminal device 10n + 3 and the (N + 4) th terminal device 10n + 4 is instructed. That is, the formation of two groups is instructed. Next, in step 2, the connection between the (N + 1) th terminal apparatus 10n + 1 and the (N + 3) th terminal apparatus 10n + 3 is instructed. That is, by joining the two groups, it is instructed to form another ad hoc network. Further, in step 3, the N + 1th terminal apparatus 10n + 1 is instructed to connect to the third terminal apparatus 10c. That is, when another ad hoc network is connected to the third terminal apparatus 10c, the (N + 1) th terminal apparatus 10n + 1 to the (N + 4) terminal apparatus 10n + 4 are connected to the third terminal apparatus 10c. Returning to FIG.

  FIG. 6B shows processing subsequent to FIG. 6A and shows the processing in step 1 described above. That is, after receiving the instruction signal, the (N + 1) th terminal apparatus 10n + 1 to the (N + 4) terminal apparatus 10n + 4 are connected to the (N + 1) th terminal apparatus 10n + 1 and the (N + 2) terminal apparatus 10n + 2 according to the instruction signal. Are connected to the (N + 4) th terminal device 10n + 4. Such a connection may be realized by a known technique. FIG. 6C shows processing subsequent to FIG. 6B, and shows the processing in step 2 described above. That is, the (N + 1) th terminal apparatus 10n + 1 and the (N + 3) th terminal apparatus 10n + 3 are connected. In FIG. 6C, for convenience, the N + 2 terminal device 10n + 2 and the N + 3 terminal device 10n + 3 are shown to be connected.

  Here, the first group 110a is formed by the (N + 1) th terminal apparatus 10n + 1 and the (N + 2) terminal apparatus 10n + 2, and the second group 110b is formed by the (N + 3) terminal apparatus 10n + 3 and the (N + 4) terminal apparatus 10n + 4. . Therefore, FIG. 6C corresponds to two groups being combined. FIG. 6D shows the process following FIG. 6C, and shows the process of step 3 described above. That is, the first terminal device 10a and the third terminal device 10c are connected. The ad hoc network 112 is formed by the (N + 1) th terminal device 10n + 1 to the (N + 4) th terminal device 10n + 4. Therefore, FIG. 6D corresponds to the connection between the communication system 100 and the ad hoc network 112.

  FIG. 8 is a flowchart showing a connection procedure in the terminal device 10. The control unit 18 receives a connection request, that is, the above-described request signal via the wireless unit 12 or the like (S50). If the number of request signals is greater than or equal to A (Y in S52), the control unit 18 selects group connection (S54). On the other hand, if the number of request signals is not equal to or greater than A (N in S52), the control unit 18 selects direct connection (S56).

  Hereinafter, modified examples will be described. In the modification, it is assumed that the number of requesting terminal devices 10 is further increased than in the embodiment. In the modification, the purpose is to further shorten the connection processing period compared to the connection processing by group connection. In the group connection, while the requesting terminal device 10 forms a group and another ad hoc network, the responding terminal device 10 waits for the completion of another ad hoc network. In the modification, the group connection is performed on a part of the plurality of requesting terminal devices 10 and the direct connection is performed on the remaining requesting terminal devices 10. That is, group connection and direct connection are executed in parallel (hereinafter referred to as “mixed connection”). By such processing, the response-side terminal device 10 connects the request-side terminal device 10 even during the period until another ad hoc network is completed, so that the connection processing period can be shortened.

  The configuration of the terminal device 10 here is the same as the type shown in FIG. When the responding terminal device 10 enters the approval mode, as described above, the control unit 18 receives a request signal from the requesting terminal device 10 over a predetermined period. Here, the control unit 18 receives a plurality of request signals in a predetermined period. Further, the control unit 18 calculates the number of received request signals. The control unit 18 selects any one of direct connection execution, group connection execution, and mixed connection execution based on the calculation result while referring to the threshold value stored in the storage unit 20.

  FIG. 9 shows a data structure of threshold values stored in the storage unit 20 according to the modification of the present invention. Similar to FIG. 5, a number column 200 and a connection procedure column 202 are included. The control unit 18 compares the calculation result with the thresholds “A” and “B”. Here, B is assumed to be larger than A. If the calculation result is smaller than A, the control unit 18 selects direct connection. On the other hand, when the calculation result is A or more, if the calculation result is smaller than B, the group connection is selected, and if the calculation result is B or more, the mixed connection is selected. Since the direct connection and the group connection may be executed as described above, description thereof is omitted here.

  When the mixed connection is selected, the control unit 18 forms another ad hoc network for a part of the plurality of requesting terminal devices 10 and then executes an approval process for another ad hoc network. . That is, the control unit 18 performs group connection to some of the request side control units 18. In addition, the control unit 18 performs direct connection to the remaining requesting terminal device 10. Therefore, the control unit 18 divides the plurality of requesting terminal devices 10 into two groups, performs direct connection to one group (hereinafter, referred to as “first group”), and performs another one group ( Hereinafter, group connection is executed for “second group”.

  Note that each of the direct connection and the group connection may be executed as described above, and a description thereof will be omitted here. The control unit 18 classifies the plurality of requesting terminal devices 10 into two groups based on the received power in the request signals from the requesting terminal devices 10. Specifically, the control unit 18 includes the X terminal devices 10 having higher received power values in the first group, and includes the remaining 10 in the second group. Note that the group connection and direct connection procedures are notified from the response-side terminal device 10 to the request-side terminal device 10, and the details will be described later.

  FIGS. 10A to 10D show an outline of a connection procedure in the communication system 100 according to the modification of the present invention. Here, the procedure of mixed connection is shown in particular. In FIG. 10A, the (N + 1) th terminal device 10n + 1 to the (N + 6) th terminal device 10n + 6 correspond to the requesting terminal device 10, and the third terminal device 10c corresponds to the responding terminal device 10. Further, although the communication system 100 includes a plurality of terminal devices 10, the description is omitted here for the sake of clarity. The (N + 1) th terminal device 10n + 1 to the (N + 6) th terminal device 10n + 6 are in the request mode, and the third terminal device 10c is in the approval mode. Under such circumstances, the (N + 1) th terminal device 10n + 1 to the (N + 6) th terminal device 10n + 6 transmit a request signal. The third terminal apparatus 10c determines the execution of the mixed connection and also determines the direct connection and group connection procedures included in the mixed connection. The third terminal apparatus 10c notifies the procedure from the (N + 1) th terminal apparatus 10n + 1 to the (N + 6) th terminal apparatus 10n + 6 as an instruction signal.

  FIG. 11 shows a data structure of the instruction signal generated in the control unit 18 according to the modification of the present invention. Similar to FIG. 7, a step column 210 and a connection column 212 are included. First, in step 1, the connection between the (N + 1) th terminal device 10n + 1 and the (N + 2) th terminal device 10n + 2 is instructed, and the connection between the (N + 3) th terminal device 10n + 3 and the (N + 4) th terminal device 10n + 4 is instructed. That is, the formation of two groups is instructed. In addition, the N + 5 terminal device 10n + 5 is instructed to connect to the third terminal device 10c. That is, execution of direct connection to the (N + 5) th terminal device 10n + 5 is instructed.

  Next, in step 2, the connection between the (N + 1) th terminal apparatus 10n + 1 and the (N + 3) th terminal apparatus 10n + 3 is instructed. That is, by joining the two groups, it is instructed to form another ad hoc network. In addition, the N + 6 terminal apparatus 10n + 6 is instructed to connect to the third terminal apparatus 10c. That is, execution of direct connection to the (N + 6) th terminal device 10n + 6 is instructed. Further, in step 3, the N + 1th terminal apparatus 10n + 1 is instructed to connect to the third terminal apparatus 10c. That is, when another ad hoc network is connected to the third terminal apparatus 10c, the (N + 1) th terminal apparatus 10n + 1 to the (N + 4) terminal apparatus 10n + 4 are connected to the third terminal apparatus 10c. Returning to FIG.

  FIG. 10B shows the process following FIG. 10A, and shows the process of step 1 described above. That is, after receiving the instruction signal, the (N + 1) th terminal apparatus 10n + 1 to the (N + 4) terminal apparatus 10n + 4 are connected to the (N + 1) th terminal apparatus 10n + 1 and the (N + 2) terminal apparatus 10n + 2 according to the instruction signal. Are connected to the (N + 4) th terminal device 10n + 4. Further, the (N + 5) th terminal device 10n + 5 is connected to the third terminal device 10c according to the instruction signal.

  FIG. 10C shows the process following FIG. 10B, and shows the process of step 2 described above. That is, the (N + 1) th terminal apparatus 10n + 1 and the (N + 3) th terminal apparatus 10n + 3 are connected. In FIG. 10C, for convenience, the N + 2 terminal device 10n + 2 and the N + 3 terminal device 10n + 3 are shown to be connected. Here, the first group 110a is formed by the (N + 1) th terminal apparatus 10n + 1 and the (N + 2) terminal apparatus 10n + 2, and the second group 110b is formed by the (N + 3) terminal apparatus 10n + 3 and the (N + 4) terminal apparatus 10n + 4. . Therefore, FIG. 10C corresponds to the combination of two groups. The N + 6 terminal apparatus 10n + 6 is connected to the third terminal apparatus 10c according to the instruction signal.

  FIG. 10D shows the process following FIG. 10C, and shows the process of step 3 described above. That is, the first terminal device 10a and the third terminal device 10c are connected. The ad hoc network 112 is formed by the (N + 1) th terminal device 10n + 1 to the (N + 4) th terminal device 10n + 4. Therefore, FIG. 10D corresponds to the connection between the communication system 100 and the ad hoc network 112.

  FIG. 12 is a flowchart showing a connection procedure in the terminal device 10 according to the modification of the present invention. The control unit 18 receives a connection request, that is, the above-described request signal via the wireless unit 12 or the like (S80). If the number of request signals is greater than or equal to A (Y in S82) and greater than or equal to B (Y in S84), the control unit 18 selects a mixed connection (S86). On the other hand, if it is not more than B (N of S84), the control part 18 will select group connection (S90). If the number of request signals is not A or more (N in S82), the control unit 18 selects direct connection (S88).

  Hereinafter, another modification will be described. Up to now, the response-side terminal device 10 has switched direct connection or the like according to the number of request-side terminal devices 10. However, in another modification, the processing capability of the CPU provided in the terminal device 10 is reduced. Change the direct connection etc. accordingly. For example, the responding terminal device 10 selects one of direct connection, group connection, and mixed connection according to the processing capability of its own CPU. Here, the processing capability of the CPU is determined based on the clock frequency and the number of cores. The terminal device 10 selects direct connection as the processing capacity of the CPU increases, and sequentially selects mixed connection and group connection as the processing capacity decreases. As the processing capacity of the CPU, a value obtained by subtracting the processing capacity currently used from the processing capacity originally possessed may be used.

  Further, when executing the direct connection, the responding terminal device 10 connects in order from the requesting terminal device 10 having a high CPU processing capacity. It is assumed that the request signal includes the value of the processing capability provided in the requesting terminal device 10. According to such a rule, the terminal device 10 that can be connected quickly is connected first. On the other hand, when executing the group connection, the responding terminal device 10 causes the terminal device 10 having a high CPU processing capability and the terminal device 10 having a low CPU processing capability to be grouped in accordance with the processing capability of the requesting terminal device 10. To instruct. Further, the terminal device 10 on the response side may execute mixed connection by a combination of the above processes.

  Although it is different from the processing speed of the CPU, the responding terminal device 10 prioritizes connection based on the type of the requesting terminal device 10 when executing the direct connection in relation to the processing speed of the CPU. The order may be determined. For example, the terminal device 10 on the response side includes information indicating what kind of device it is in a beacon and broadcasts the beacon. An example of what kind of device is a PC, PDA, or the like. On the other hand, the requesting terminal device 10 includes information indicating what kind of terminal it is in the request signal, and transmits the request signal. The terminal device 10 on the response side assigns priority in advance according to the type of the terminal device 10 and connects in order from the terminal device 10 with the highest priority.

  Hereinafter, still another modification will be described. In yet another modified example, the responding terminal device 10 switches the direct connection or the like according to the state of the communication system 100 already formed, regardless of the requesting terminal device 10. For example, the responding terminal device 10 selects group connection as the number of terminal devices 10 already connected to the communication system 100 increases, and performs mixed connection and direct connection as the number of terminal devices 10 decreases. Select in order. Further, the responding terminal device 10 may select group connection, mixed connection, or direct connection according to the amount of traffic in the communication system 100 instead of the number of the terminal devices 10 included in the communication system 100. Good. For example, the responding terminal device 10 selects the group connection as the traffic amount in the communication system 100 increases, and sequentially selects the mixed connection and the direct connection as the traffic amount decreases.

  According to the embodiment of the present invention, a plurality of terminal devices are formed with different ad hoc networks, and the approval process is executed for the different ad hoc networks. Therefore, when the number of terminal devices increases or in the ad hoc network Even when the load increases, an increase in the connection period can be suppressed. Also, even when the number of terminal devices increases or when the load on the ad hoc network increases, the increase in the connection period is suppressed, so the terminal suitable for the number of new terminal devices or the state of the ad hoc network Device connection can be performed. In addition, a separate ad hoc network is formed for some terminal devices, the approval process is executed for another ad hoc network, and the remaining terminal devices are directly connected, resulting in an increase in the number of terminal devices. Even when the load on the ad hoc network increases, the increase in the connection period can be suppressed.

  Further, since direct connection or group connection is selected according to the number of requesting terminal devices, an increase in the connection period can be suppressed even if the number of terminal devices increases. Also, since direct connection or group connection is selected according to the number of requesting terminal devices, the terminal devices can be easily connected when the number of terminal devices decreases. Further, when the number of requesting terminal devices further increases, a mixed connection is selected, so that an increase in connection period can be suppressed even if the number of terminal devices increases. In addition, since the connection method is selected according to the CPU processing capability of the terminal device, it is possible to execute connection of the terminal device suitable for the state of the ad hoc network. Further, since the connection method is selected according to the traffic volume of the ad hoc network, it is possible to execute connection of a terminal device suitable for the state of the ad hoc network.

  In the above, this invention was demonstrated based on the Example. This embodiment is an exemplification, and it will be understood by those skilled in the art that various modifications can be made to the combination of each component and each processing process, and such modifications are also within the scope of the present invention. .

  In the embodiment of the present invention, the terminal device 10 performs the connection process and the transfer process while using the same radio unit 12 and modem unit 14. That is, both processes are executed using the wireless LAN. However, the present invention is not limited to this. For example, another wireless unit 12 and a modem unit 14 may be used for connection processing and transfer processing. That is, the wireless LAN is used for the transfer process, but another communication system may be used for the connection process. The reverse is also possible. According to this modification, the degree of freedom of the configuration of the communication system can be improved.

  In the embodiment of the present invention, the responding terminal device 10 selects group connection, mixed connection, or direct connection. However, the present invention is not limited to this. For example, the response-side terminal device 10 may perform group connection or mixed connection in a fixed manner. At that time, the part related to the group connection or the part related to the mixed connection in the above description is effective. According to this modification, the selection process in the terminal device 10 on the response side can be omitted.

It is a figure which shows the structure of the communication system which concerns on the Example of this invention. It is a figure which shows the structure of the terminal device of FIG. It is a figure which shows the data structure of the routing table memorize | stored in the memory | storage part of FIG. It is a sequence diagram which shows the connection procedure in the communication system of FIG. It is a figure which shows the data structure of the threshold value memorize | stored in the memory | storage part of FIG. 6A to 6D are diagrams showing an outline of a connection procedure in the communication system of FIG. It is a figure which shows the data structure of the instruction | indication signal produced | generated in the control part of FIG. It is a flowchart which shows the connection procedure in the terminal device of FIG. It is a figure which shows the data structure of the threshold value memorize | stored in the memory | storage part which concerns on the modification of this invention. FIGS. 10A to 10D are diagrams showing an outline of a connection procedure in the communication system according to the modification of the present invention. It is a figure which shows the data structure of the instruction | indication signal produced | generated in the control part which concerns on the modification of this invention. It is a flowchart which shows the connection procedure in the terminal device which concerns on the modification of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 Terminal device, 12 Radio | wireless part, 14 Modulator / demodulator, 16 Processing part, 18 Control part, 20 Storage part, 22 Operation part, 24 Monitor, 26 Speaker, 100 Communication system.

Claims (7)

A communication unit that performs communication while forming an ad hoc network with another terminal device; and
When a role that should approve participation of a new terminal device to the ad hoc network formed in the communication unit is assigned, a reception unit that receives a participation request from the new terminal device through the communication unit;
A processing unit that executes an approval process for the participation request received in the reception unit;
A notification unit for notifying the result of the approval process executed in the processing unit,
When the accepting unit receives a participation request from a plurality of new terminal devices, the processing unit forms another ad hoc network between the plurality of new terminal devices, and performs an approval process on another ad hoc network. A terminal device that is executed. A communication unit that performs communication while forming an ad hoc network with another terminal device; and
When a role that should approve participation of a new terminal device to the ad hoc network formed in the communication unit is assigned, a reception unit that receives a participation request from the new terminal device through the communication unit;
A processing unit that executes an approval process for the participation request received in the reception unit;
A notification unit for notifying the result of the approval process executed in the processing unit,
When the accepting unit receives a participation request from a plurality of new terminal devices, the processing unit may form another ad hoc network for a part of the plurality of new terminal devices, A terminal device that performs an approval process on an ad hoc network and executes a direct approval process on the rest. A communication unit that performs communication while forming an ad hoc network with another terminal device; and
When a role that should approve participation of a new terminal device to the ad hoc network formed in the communication unit is assigned, a reception unit that receives a participation request from the new terminal device through the communication unit;
A processing unit that executes an approval process for the participation request received in the reception unit;
A notification unit for notifying the result of the approval process executed in the processing unit,
When the accepting unit receives a participation request from a plurality of new terminal devices, the processing unit forms another ad hoc network between the plurality of new terminal devices, and performs an approval process on another ad hoc network. A terminal device characterized by executing either a first process to be executed or a second process for executing a direct approval process for each of a plurality of new terminal devices.   When the receiving unit receives a participation request from a plurality of new terminal devices, the processing unit forms another ad hoc network for a part of the plurality of new terminal devices, A third process for executing an approval process for the ad hoc network and a direct approval process for the rest can be executed, and any one of the first process to the third process is executed. The terminal device according to claim 3. Executing communication while forming an ad hoc network with another terminal device; and
Receiving a participation request from a new terminal device when a role to approve participation of the new terminal device in the ad hoc network is assigned;
A step of executing an approval process for the accepted participation request,
The step of executing the approval process is to form another ad hoc network between the plurality of new terminal devices when receiving a participation request from a plurality of new terminal devices, and to perform the approval process for another ad hoc network. A communication method characterized by being executed. Executing communication while forming an ad hoc network with another terminal device; and
Receiving a participation request from a new terminal device when a role to approve participation of the new terminal device in the ad hoc network is assigned;
A step of executing an approval process for the accepted participation request,
The step of executing the approval process, when receiving a participation request from a plurality of new terminal devices, after forming another ad hoc network for a part of the plurality of new terminal devices, A communication method characterized by executing an approval process on an ad hoc network and executing a direct approval process on the rest. Executing communication while forming an ad hoc network with another terminal device; and
Receiving a participation request from a new terminal device when a role to approve participation of the new terminal device in the ad hoc network is assigned;
A step of executing an approval process for the accepted participation request,
The step of executing the approval process is to form another ad hoc network between the plurality of new terminal devices when receiving a participation request from a plurality of new terminal devices, and to perform the approval process for another ad hoc network. A communication method characterized by executing either a first process to be executed or a second process for executing a direct approval process for each of a plurality of new terminal devices.

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