JPH10145276A - Ad hoc network system and its connecting method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent communication faults which are caused by the insufficient capability of a master unit about an ad hoc network system that consists of plural slave units and a master unit. SOLUTION: An ad hoc network is reconstructed with the optimum radio terminal as a master unit made its master unit, by deciding an interim master unit 101 among plural radio terminals which can be either a master unit or a slave unit, collecting a transfer rate that is measured by using a test signal and the remaining amount of battery of each slave unit 102 to 104 by the unit 101, when data exchange is available between the other radio terminals 102 to 104 and the unit 101 and newly reselecting a true master unit based on collected information.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ad hoc network system for communicating only between a limited number of wireless terminals.
The present invention relates to an ad hoc network system that communicates via a parent device and a connection method thereof.

[0002]

2. Description of the Related Art In a conventional ad hoc network, a dedicated master unit having a higher processing capability than a slave unit is prepared in advance, and a master unit interposition method for configuring a network and a wireless terminal that transfers data are used. A terminal direct method that configures a network by re-establishing synchronization each time is used.

Japanese Patent Application Laid-Open No. Hei 4-366148 discloses a line allocating means for allocating a single wireless line to a plurality of slave units, and determining which slave unit is transmitting on a single wireless line. It is an object of the present invention to provide a communication state monitoring means for monitoring so that many slave units can make conference calls with low-cost and simple devices.

[0004] Japanese Patent Application Laid-Open No. 7-303280 discloses that
A mobile wireless switchboard is provided with a communication limit defining means for joining a group and defining a maximum number of simultaneous calls for communication within the group, and an ad hoc network is configured by controlling intra-group traffic.

[0005]

However, in the ad hoc network in the method of interposing the master unit, if a master unit having a sufficient data transfer rate and a sufficient remaining storage battery cannot be prepared, the transfer rate of the master unit is determined by the transfer rate of the master unit. Problems such as a reduction in speed and disconnection of the communication line due to a battery shortage of the master unit occur.

An object of the present invention is to provide an aco-hoc network system in which the remaining amount of a storage battery is equal to or more than a predetermined amount and communication with a master unit having the highest transfer rate is possible.

[0007]

In order to achieve the above object, a method for connecting an ad hoc network system according to the present invention is a method for connecting an ad hoc network system which is a mutual wireless communication network system between limited wireless terminals. A wireless terminal that does not have the parent device and that satisfies a specific condition when the parent device is undecided is selected as the parent device.

[0008] Further, the specific condition is that the optimum condition as a master unit has a power supply remaining capacity equal to or greater than a predetermined value and a maximum transfer rate. It is preferable that the wireless terminal that has generated the request becomes a temporary master unit, collects the data of the remaining power supply and the transfer rate of all wireless terminals, and determines the master unit by comparing the results.

Further, a specific wireless connection method is a communication connection method of an ad hoc network system, wherein a wireless terminal that has requested transmission when no synchronization signal is transmitted becomes a temporary master device and transmits a synchronization signal. The step, the other wireless terminals that have received the synchronization signal from the temporary master unit become slave units and synchronize with the received synchronization signal, and the wireless terminal that becomes the slave unit is uniquely assigned. Sending an identifier, the provisional master unit collecting current power remaining capacity and transfer rate data of all slave units, and selecting a true master unit from the data collected by the provisional master unit And disseminating the identifier of the true master to all slaves; stopping the temporary master to stop sending the synchronization signal; and sending the true master to the synchronization signal.
Synchronizing all the slaves with the newly received synchronization signal.

Further, the ad hoc network system of the present invention stores channel scanning means for scanning a wireless channel, transmitting / receiving means for transferring data on the wireless channel, and an identifier uniquely assigned to each wireless terminal. Each wireless terminal having an identifier storage means, a synchronization signal detection means for detecting the presence or absence of a synchronization signal being transmitted, and a means for synchronizing with the detected synchronization signal,
The base unit identifier storage unit in which the identifier of the base unit is stored, and when a transmission request occurs, the synchronization signal detection unit starts synchronization signal detection, and when the absence of a synchronization signal is detected, the provisional base unit becomes the temporary base unit, Means for storing the identifier in the base unit identifier storage means, means for transmitting a synchronization signal to a predetermined wireless channel when the provisional base unit is provided, and the identifier of the own wireless terminal as the provisional base unit to other wireless terminals. Upon detecting the notification means and the synchronization signal transmitted by the other wireless terminal, the mobile terminal becomes
Means for synchronizing with the detected synchronization signal, and upon receiving the notification of the identifier from the temporary master, storing the notified identifier of the master in the master identifier storage, and storing the own wireless terminal in the identifier storage. Means for notifying the temporary master to the temporary master, data collection means for collecting data of the remaining power supply and the communication transfer rate from each slave when receiving the identifier from each slave as the temporary master, and Selecting means for selecting a true master unit that satisfies a predetermined condition from the data; and re-instructing all wireless terminals with the identifier of the wireless terminal selected as the true master unit, instructing reconnection and stopping transmission of a synchronization signal. When the connection instruction means and the reconnection instruction are received, the designated identifier is stored in the parent device identifier storage device, and when the identifier matches the own identifier, the means for transmitting a synchronization signal as a true parent device is activated. When they do not match Having a re-connection means for aligning synchronization with the synchronizing signal true master unit is transmitted.

A second slave unit identifier storing means for storing an identifier of the wireless terminal with which the wireless terminal has been communicating before the primary and true master unit switching, and a second slave unit identifier; A slave unit identifier comparing unit that compares the identifier stored in the storage unit with the identifier of the slave unit that is currently performing communication, wherein the temporary master unit issues a reconnection request for reconfiguring the network. When notifying the slaves, the identifiers of all the slaves that have been communicating so far are also notified, and the true master stores the notified identifier in the second slave identifier storage means,
After the network is reconfigured, the slave unit identifier comparison unit detects a wireless terminal that is not continuously connected due to switching of the master unit, and the wireless terminal creates test data as data collection unit. Test signal generating means, first measuring means for measuring a transfer rate by transmitting and receiving test data to and from each slave unit based on retransmission control, and second measuring means for measuring the remaining amount of the storage battery by the slave unit.
Each of the slave units notifies the master unit of the remaining amount of the storage battery obtained by the second measurement unit, and the provisional master unit has the measurement result notified from each slave unit, Based on the test data generated by the test signal generating means and the transfer rate with each slave obtained by executing the first measuring means, the selecting means selects a true master unit and re-establishes the network. Constituents are preferred.

[0012] The wireless terminal may further include a measurement result storage means for storing a transfer rate measurement result obtained by the first measurement means and a storage battery remaining amount obtained by the second measurement means; Monitoring means for periodically monitoring the remaining capacity of the storage battery obtained by the second measuring means, and when the monitoring means of the master unit detects that the remaining capacity of the storage battery has decreased below a reference value, It is preferable that the master unit selecting unit determines a true master unit from the measurement results stored by the measurement result storage unit and reconnects the network.

That is, all the radio terminals are radio terminals that can operate as both the parent device and the child device, and the radio terminal that has generated a call request among them is the temporary parent device, and all the other radio terminals are the child devices. When the data transfer becomes possible by synchronizing with the master unit as a unit, the provisional large house unit measures the transfer rate with each slave unit using the test signal, and The above object is achieved by re-selecting a new optimal wireless terminal as a true master device based on the remaining amount of the storage battery of the device and reconfiguring the network.

By configuring the above system, even when a wireless terminal having a sufficient function as a master unit cannot be prepared or when it is not known which wireless terminal is suitable for the master unit, an appropriate wireless terminal can be used. Since the master unit can be used, it is possible to prevent a reduction in the speed of the entire network due to the transfer rate of the master unit and a reduction in the connection time due to an insufficient remaining amount of the storage battery.

[0015]

Embodiments of the present invention will be described with reference to the drawings.

Each of the wireless terminals 101 to 104 having the same functions shown in FIG. 1 includes a synchronization notifying unit 106, a scanning unit 107 for scanning a wireless channel, and a transmitting and receiving unit 108 for transmitting and receiving data using the wireless channel. And an identifier storage unit 109 for storing a unique identifier for each wireless terminal.
And a base unit identifier storage unit 110 for storing a base unit identifier.
A mode setting unit 111 that determines the operation of the wireless terminal at the time of initial connection using the scanning unit 107; a test signal generation unit 112; and the test signal generation unit 112 sets the transfer rate between the slave units. A speed measuring unit 113 for measuring, a remaining amount detecting unit 114 for detecting the remaining amount of the storage battery, a monitoring unit 115 for periodically executing the means, and a first unit for storing the current identifier of each slave unit in the master unit. Child device identifier storage unit 116
A second child device identifier storage unit 117 for storing the identifier of the child device that was communicating before the parent device was switched, a parent device selection unit 118 for determining a new parent device, and a device for operating as a parent device. The wireless communication apparatus includes a master unit control unit 119 and a control unit 121 including a slave unit control unit 120 for operating as a slave unit, and transmits and receives data on the wireless channel 105.

First, each of the wireless terminals 101 to 104 scans a wireless channel by the scan unit 107 by the mode setting unit 111, and when the synchronization signal is not broadcast on the wireless channel 105, the master unit control unit 119 The synchronization notification unit 106 notifies the synchronization signal on the wireless channel 105, and stores the identifier assigned to the own wireless terminal stored in the identifier storage unit 109 in the base unit identifier storage unit 110.
And waits for a response from another wireless terminal.

When the synchronization signal is broadcast on the radio channel 105, the slave unit control unit 120 synchronizes the synchronization signal with the synchronization signal in the scanning unit 107, and
8 enables data exchange with the master unit, sends the identifier stored in the identifier storage unit 109 to the master unit, and the master unit replaces the identifier sent from each slave unit with the first slave unit identifier. The identifier is stored in the storage unit 116, and the identifier of the master unit is sent to the slave unit as a response, and the slave unit receiving the identifier stores the identifier of the master unit in the master unit identifier storage unit 110.

Here, a description will be given on the assumption that the wireless terminal 101 is a master unit and the wireless terminals 102 to 104 are slave units.

Next, each of the slave units 102 to 104 detects the remaining amount of the storage battery by the remaining amount detection unit 114 and sends it to the master unit by the transmission / reception unit 108. The master unit 101 checks the remaining amount of the storage battery. ,
Using the test data created by the test signal generator 112 and the transfer rate between each slave obtained by the speed measuring means 113, the master selector 118 selects a new true master. .

Next, the current provisional master unit stores the identifier of the wireless terminal newly selected as the true master unit and the identifiers of all the slave units stored in the first slave unit identifier storage unit 116. Each of the wireless terminals receiving the reconnection request stores a new true parent device identifier in the parent device identifier storage means 110.

The wireless terminal that has become the new true master unit stores the identifiers of all wireless terminals sent from the temporary master unit in the second slave unit identifier storage unit 117, and thereafter, the synchronization notification unit 1
At 06, a synchronization signal is reported. Also, the wireless terminal that has become a child unit notifies the identifier stored in the identifier storage unit 109 to the new true parent unit, and the true parent unit sends the transmitted identifier of the child unit to the first child unit. It is stored in the device identifier storage unit 116.

After waiting a sufficient time to connect to each wireless terminal, the true master unit stores the identifier stored in the first slave unit identifier storage unit 116 and the second slave unit identifier storage unit. By comparing the identifier with the identifier stored in the unit 117, it is checked whether there is any wireless terminal that is not connected due to the switching of the master unit.

[0024]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the ad hoc network system of the present invention will be described with reference to the drawings.

FIG. 2 is a block diagram of Embodiment 1 of the ad hoc network system of the present invention. Each wireless terminal 20
Reference numerals 1 to 204 denote a CPU (central processing unit) 205 for controlling the entire apparatus, a RAM 206 for storing a control program and a control database, a ROM 207 for storing a bootstrap program for starting up the apparatus,
Disk device 208 for storing an OS for controlling the device, storage battery remaining amount detection device 209 for measuring the remaining amount of storage battery, input device 210 for receiving input from the user, display device 211 for outputting to the user, control of wireless communication And an antenna 213.

Further, on the RAM 206 of each wireless terminal,
As shown in FIG. 3A, there are provided a terminal identifier table 301 for storing identifiers assigned to the respective wireless terminals, and a base unit identifier table 302 for storing the identifiers of the wireless terminals that are currently the base units. Furthermore, in the parent machine, FIG.
As shown in (b), the identifier 303 for identifying the slave unit performing communication, the transfer rate 304 for storing the transfer speed between each slave unit, and the remaining amount of the storage battery of each slave unit are stored. It stores a database consisting of a storage battery remaining amount 305 and a continuation flag 306 for confirming whether communication can be continued when the master unit is switched.

The continuation flag 306 plays the same role as the second slave unit identifier 117 of the wireless terminal 101 shown in the embodiment of the present invention.

If the identifiers stored in the terminal identification table 301 and the identifiers stored in the base unit identification table 302 are equal, all the wireless terminals 201 to 204 operate as base units, and If it is, the program is programmed on the RAM 206 to operate as a slave.

Next, the operation of the first embodiment will be described with reference to the flowcharts shown in FIGS. Here, the flow A indicates the operation as the master unit, and the flow B indicates the operation as the slave unit.

First, all the wireless terminals 201 to 204
The wireless adapter 212 scans the wireless channel to check whether or not the synchronization signal has already been broadcast on the wireless channel (step 401). If the synchronization signal has not been broadcast, the identifier of the terminal identification table 301 is replaced with the master unit identification table. After storing the information in the storage device 302, the display device 210 becomes a parent device, and the information is displayed to the user using the display device 210 (step 40).
2), a synchronization signal is broadcast on the wireless channel (step 403). If the synchronization signal is broadcast, the fact that the mobile phone has become a slave is displayed to the user using the display device 210 (step 403). 404), data transfer with the master unit is enabled by synchronizing with the synchronization signal reported by the master unit (step 405).

Next, each slave unit is connected to the terminal identification table 301.
Is transmitted to the base unit using the identifier stored in the base unit (step 406). When the base unit confirms that there is a connection request from the base unit (step 407), the base unit The identifier is stored in the identifier 303 of the database (FIG. 3) (step 408), and the identifier of the master unit is notified to the slave unit (step 409). Upon receiving the notification (step 410), the slave unit stores the notified identifier of the master unit in master unit identification table 302 (step 411).

Here, it is assumed that the wireless terminal 201 has become the master unit, and the wireless terminals 202 to 204 have become the slave units. To 216 are used.

Next, the temporary master device 201 waits for a connection request from each wireless terminal for a predetermined time, and then automatically inputs a master device change request to the input device 211 (step 412). In order to obtain the remaining amount of the storage battery, a remaining amount acquisition request is notified to all the slaves (step 413). When each slave receives the remaining amount acquisition request (step 414), the remaining amount detection device 209 sets the remaining amount of the storage battery. The amount is detected (step 41
5) Then, the master unit is notified (step 416), and when the remaining amount of the storage battery is received by the master unit (step 417), it is stored in the storage battery remaining amount 305 of the corresponding slave unit (step 418).

When the remaining amount of the storage battery is received from all the slaves (step 419), test data is created, the test data is transmitted to the 202 slave (step 501), and when the slave receives the test data (step 501). Step 502) Return the test data as it is to the master unit (Step 503), and receive the returned test data by the master unit (Step 5).
04), the transfer rate with the slave unit is measured, and the measured transfer rate (for example, b based on 100 kB test data)
The procedure of storing the (ps value) in the transfer rate 304 of the child device 202 (step 505) is repeated until the procedure is executed between all the child devices 202 to 204 (steps 501 to 50).
6).

After measuring the transfer rate with all the slaves, using the database (FIG. 3), the most transfer is performed from the wireless terminals having the remaining amount of the storage battery equal to or more than a certain value (for example, 70%). A wireless terminal having a fast rate is selected as a new true master (step 507), and as a master switching request,
The database (FIG. 3) in which the identifier of the new true master unit and the continuation flag 305 are cleared is notified to all slave units (step 508).

When each of the slaves receives the parent switching request (step 509), the notified identifier of the new master is stored in the master identification table 302, and the identifier of the new master and the terminal identification table 301 are stored. If the result of the comparison does not match, the user is notified on the display device 210 that the terminal has become a slave (step 511), and the new true Synchronize with the synchronization signal with the master unit (step 512), and notify the true master unit of the identifier of the own wireless terminal (step 51).
3) Complete the reconnection. If the comparison results in a match, the display device 210 displays to the user that the device has become the master device (step 514), and the database (FIG. 3) sent from the temporary master device is stored in the database of the own wireless terminal. (FIG. 3) (step 515), and the synchronization signal is transmitted and notified on the wireless channel (step 516).

In the new true master unit, every time a connection request is received from the slave unit (step 517), the continuation flag of the received identifier is set (step 518). (Step 519), the slave unit that is not connected is notified to the user on the display device 210 (Step 520), and the waiting for a connection request from the slave unit is continued (Steps 517 to 520).

Then, when all the continuation flags are set, the reconnection is completed, and the reconfiguration of the network is completed.

If a wireless terminal that cannot continue communication remains due to the switching of the master unit, it is determined that the switching of the master unit has failed, and the network may be reconfigured with the previous master unit. If, for example, the connection cannot be established due to poor reception conditions, the connection may be established by moving the wireless terminal to a location having good reception conditions.

[0040]

As described above, the feature of the ad hoc network of the present invention resides in that the most suitable radio terminal for the master unit can be selected from a plurality of radio terminals.
Even if a special master unit is not prepared in advance, there is an effect that the entire network is prevented from being slowed down by the transfer rate of the master unit, and the network connection time is prevented from being shortened due to insufficient remaining storage battery of the master unit.

[Brief description of the drawings]

FIG. 1 is a system configuration diagram of an ad hoc network system of the present invention.

FIG. 2 is a block diagram of Embodiment 1 of the ad hoc network system of the present invention.

3A and 3B are explanatory diagrams of data stored in a wireless terminal according to the first embodiment illustrated in FIG. 2, wherein FIG. 3A is a diagram illustrating a terminal identification table and a parent device identification table, and FIG. 3B is a diagram illustrating a database.

FIG. 4 is a flowchart illustrating an operation according to the first exemplary embodiment illustrated in FIG. 2;

FIG. 5 is a flowchart following the flowchart shown in FIG. 4;

[Explanation of symbols]

 101, 102, 103, 104 Wireless terminal 105 Wireless communication path 106 Synchronization notification unit 107 Wireless scanning unit 108 Transmission / reception unit 109 Identifier storage unit 110 Mode identification unit 111 Mode setting unit 112 Test signal generation unit 113 Speed measurement unit 114 Remaining amount detection unit 115 monitoring unit 116 first slave unit identifier storage unit 117 second slave unit identifier storage unit 118 master unit selection unit 119 master unit control unit 120 slave unit control unit 121 control unit

Claims (7)

[Claims] 1. A connection method for an ad hoc network system, which is an inter-wireless communication network system between limited wireless terminals, wherein a wireless terminal that does not have a dedicated parent device and satisfies a specific condition when a parent device is undecided. A method for connecting an ad hoc network system, wherein the method is selected as a device. 2. The method according to claim 1, wherein the specific condition is that a power supply remaining amount equal to or more than a predetermined value and a maximum transfer rate are set as optimum conditions as a master unit. The requesting wireless terminal becomes a temporary master device and collects the data of the remaining power and transfer rate of all wireless terminals,
The method according to claim 1, wherein the parent device is determined by comparing the results. 3. A communication connection method for an ad hoc network system, which is a mutual wireless communication network system between limited wireless terminals, wherein a wireless terminal that has issued a transmission request when a synchronization signal is not transmitted is a temporary master unit. Transmitting the synchronization signal from the temporary base unit, and each other wireless terminal receiving the synchronization signal from the temporary base unit becoming a slave unit and synchronizing with the received synchronization signal. Sending the temporarily assigned identifier; collecting the data of the current power remaining capacity and the transfer rate of all the slaves by the temporary master; and obtaining the true data from the data collected by the temporary master. A step of selecting a master unit, a step of informing all slave units of the identifier of the true master unit, a step in which the temporary master unit stops transmitting the synchronization signal, and the true master unit transmits the synchronization signal. Step a method of connecting the ad hoc network system, characterized by a step of all slave machine to a synchronous adjustment to the newly received synchronizing signal. 4. An ad hoc network system, which is a mutual wireless communication network system between limited wireless terminals, a channel scanning means for scanning a wireless channel, a transmitting / receiving means for transferring data on the wireless channel, Each wireless terminal having an identifier storage unit for storing an identifier uniquely assigned, a synchronization signal detection unit for detecting the presence or absence of a synchronization signal being transmitted, and a unit for synchronizing with the detected synchronization signal is provided. A base unit identifier storing means for storing an identifier of the base unit; and when a transmission request is generated, the synchronization signal detection unit starts synchronization signal detection, and when the absence of a synchronization signal is detected, the base unit becomes a provisional base unit, and its own wireless terminal. Means for storing the identifier of the base unit in the base unit identifier storage means; Means for notifying another wireless terminal of the identifier of its own wireless terminal as a provisional master unit, and detecting a synchronization signal transmitted by another wireless terminal, the slave unit becomes a slave unit, and synchronizes with the detected synchronization signal. Receiving the identifier notification from the temporary master unit, storing the notified identifier of the master unit in the master unit identifier storage unit, and replacing the identifier of the own wireless terminal stored in the identifier storage unit with the temporary master unit. Means for notifying the device, data collection means for collecting data of the remaining power supply and communication transfer rate from each of the slaves upon receiving an identifier from each of the slaves as a provisional master device, and determining predetermined conditions from the collected data. Selection means for selecting a true master unit that satisfies the condition, reconnection instruction means for indicating the identifier of the wireless terminal selected as the true master unit to all wireless terminals, instructing reconnection, and stopping transmission of a synchronization signal; Receive connection instructions An instruction identifier and stored in the parent device identifier storage unit, when said identifier matches the own identifier to activate the means for sending a synchronization signal as a true master unit,
An ad hoc network system comprising reconnection means for synchronizing with a synchronization signal transmitted by a true master unit when they do not match. 5. A second slave unit identifier storing means for storing an identifier of a wireless terminal with which the wireless terminal has been communicating before the primary and the true master unit switching, said second slave unit identifier. A slave unit identifier comparing unit that compares the identifier stored in the storage unit with the identifier of the slave unit that is currently performing communication, wherein the temporary master unit receives all of the reconnection requests for reconfiguring the network. When notifying the slave unit, the identifiers of all the slave units that have been communicating up to now are also notified. In the true master unit, the notified identifier is stored in the second slave unit identifier storage means, and the network is connected. 5. The ad hoc network system according to claim 4, wherein after the reconfiguration, the wireless terminal that is not continuously connected due to the switching of the parent device is detected by the child device identifier comparing means. 6. The wireless terminal measures a transfer rate by transmitting / receiving test data based on retransmission control to / from each slave as test data generating means for generating test data as data collecting means. A first measuring unit; and a second measuring unit for measuring the remaining amount of the storage battery by the slave unit, wherein each slave unit notifies the master unit of the remaining amount of the storage battery obtained by the second measuring unit. The provisional master unit uses the measurement result notified from each slave unit and the test data generated by the test signal generation means to generate the first master unit.
5. The ad hoc network system according to claim 4, wherein said selecting means selects a true master unit and reconfigures the network based on a transfer rate with each slave unit obtained by executing said measuring means. 7. A measurement result storage unit, wherein the wireless terminal stores a transfer rate measurement result obtained by the first measurement unit and a remaining amount of a storage battery obtained by the second measurement unit, Monitoring means for periodically monitoring the remaining amount of the storage battery obtained by the second measuring means; and when the monitoring means of the master unit detects that the remaining amount of the storage battery is smaller than the reference value. 7. The ad hoc network system according to claim 6, wherein the master unit selecting unit determines a true master unit from the measurement results stored by the measurement result storage unit and reconnects the network.