JP2005086777A - Wireless communication channel selection method, wireless communication channel selection method for master unit, and wireless data communication method for slave unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To attain effective utilization of a band for data communication. <P>SOLUTION: A master unit determines a communication time required for a slave unit on the basis of terminal type information included in a connection request signal from the slave unit (STA4). Then the master unit selects one of a plurality of data communication channels and discriminates whether or not the determined communication time can be allocated for the selected data communication channel (STA5). Further, the master unit transmits a connection request response signal including information of the selected data communication channel to the slave unit (STA6). <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a method of selecting a wireless communication channel related to setting of a communication channel in wireless communication, a method of selecting a wireless communication channel of a parent device, and a method of wireless data communication of a child device.

  As a method for realizing a wireless network, there are a centralized management method in which a master unit (control station) exists and a distributed control method in which no control station exists. The following is disclosed as one of the former centralized management methods.

The master unit (control station) has at least one control channel and a plurality of data communication channels. When the master unit allocates a data communication channel based on a connection request from the slave unit (terminal) in the control channel, the master unit performs processing in the master unit without rejecting the connection request as much as possible. Retransmission by the higher level (or application) on the side is reduced to speed up the processing (see, for example, Patent Document 1).
Japanese Patent Laid-Open No. 08-186567

  However, the publication does not mention a method for assigning the data communication channel. In addition, when there is no empty channel in the data communication channel, since the connection request is held in the master unit for a predetermined time or a specified time included in the connection request signal, the slave unit can know the success or failure of the connection quickly. In the meantime, the power consumption of the receiving circuit of the slave unit cannot be suppressed.

  Therefore, an object of the present invention is to provide a wireless communication channel selection method, a parent device wireless communication channel selection method, and a child device wireless data communication method capable of effectively using data communication bands. .

  The invention according to claim 1 is a wireless data communication system in which a parent device is connected to a network, wireless data transmission is performed between the child device and the parent device, and the child device accesses the network via the parent device. In the wireless communication channel selection method, a first wireless communication channel group including one or more wireless communication channels and a second wireless communication channel group including one or more wireless communication channels for the time division multiple access method are used. The slave unit transmits a connection request signal to the master unit via any one of the first radio communication channel groups, and the master unit receives the connection request signal from the slave unit. Based on the terminal type information included in the connection request signal, it is determined whether the slave unit performs communication by the time division multiple access method or another wireless access method, and time division When it is determined that communication is to be performed by a multiple access method, a communication time required by the slave unit is determined based on the terminal type information included in the connection request signal from the slave unit, and a predetermined selection is made Selecting one wireless communication channel from the second wireless communication channel group according to a method, determining whether the determined communication time is within a remaining allocated time of the selected wireless communication channel, and When it is determined that the communication time is within the remaining allocation time with respect to the slave unit in any one of the wireless communication channels of one wireless communication channel group, connection permission including information on the selected wireless communication channel is granted. When a first connection request response signal is transmitted and it is determined that the communication time does not fall within the remaining allocated time, a second connection request response signal indicating that connection is not permitted. In the first wireless communication channel group in the first wireless communication channel group in the wireless communication channel of the first wireless communication channel group. When transmitting a third connection request response signal for connection permission including information of one wireless communication channel, and the slave unit receives the first connection request response signal from the master unit, the first connection request response signal Communicating data through the wireless communication channel included in the wireless communication channel included in the wireless communication channel included in the third connection request response signal when receiving the third connection request response signal from the parent device. It is characterized by.

  The invention according to claim 2 is characterized in that the selection method is to select a wireless communication channel having a minimum total allocated time from the second wireless communication channel group. According to a third aspect of the present invention, in the selection method, one wireless communication channel is selected at random from the second wireless communication channel group, and the determined communication time is the remaining of the selected wireless communication channel. This is characterized in that it is selected when it falls within the allotted time, and is selected again when it does not fit. Furthermore, the invention described in claim 4 is characterized in that the selection method is to select one radio communication channel from the second radio communication channel group in a predetermined order.

  The invention described in claim 5 is characterized in that a carrier sensing scheme is used in the first wireless communication channel group. The invention described in claim 6 is characterized in that the first wireless communication channel group uses a CSMA / CA system.

  The invention according to claim 7 is a wireless data communication system in which a parent device is connected to a network, wireless data transmission is performed between the child device and the parent device, and the child device accesses the network via the parent device. In the base station wireless communication channel selection method, a first wireless communication channel group including one or more wireless communication channels, and a second wireless communication channel group including one or more wireless communication channels for the time division multiple access method, And receiving a connection request signal from the slave unit, and the slave unit communicates by a time division multiple access method based on terminal type information included in the connection request signal, or communicates by another wireless access method And when it is determined that communication is performed by the time division multiple access method, based on the terminal type information included in the connection request signal from the slave unit, The communication time required by the slave unit is determined, one wireless communication channel is selected from the second wireless communication channel group according to a predetermined selection method, and the determined wireless communication time is selected. It is determined whether the communication time is within the remaining allocation time, and it is determined that the communication time is within the remaining allocation time with respect to the slave in any one of the first wireless communication channels. A connection permission first connection request response signal including information of the selected wireless communication channel is transmitted, and when it is determined that the communication time does not fall within the remaining allocated time, a connection disapproved first connection request signal is transmitted. 2 When a connection request response signal is transmitted and it is determined that communication is performed by another wireless access method, any one of the wireless communication channels of the first wireless communication channel group Transmitting a third connection request response signal connection permission including information of one wireless communication channel in said first wireless communication channel group to the slave unit Le, characterized in that.

  The invention according to claim 8 is a wireless data communication system in which a parent device is connected to a network, wireless data transmission is performed between the child device and the parent device, and the child device accesses the network via the parent device. In the wireless data communication method of the slave unit, a first wireless communication channel group including one or more wireless communication channels and a second wireless communication channel group including one or more wireless communication channels for the time division multiple access method And the slave unit communicates with the slave unit by a time division multiple access method or another access method, and communicates with the master unit through any one of the wireless communication channels of the first wireless communication channel group. A connection request signal including terminal type information is transmitted, a response to the connection request signal is received from the base unit, and data is transmitted on one of the wireless communication channels based on the response. To signal, characterized in that.

According to the radio communication channel selection method in the radio data communication system of the present invention and the radio communication channel selection method of the master unit in the radio data communication system, when the slave unit uses the time division multiple access method, the second radio communication channel Since one wireless communication channel is selected from the group according to a predetermined selection method, and data communication is performed using the selected wireless communication channel, the band can be effectively used. In addition, since the master unit notifies the slave unit of connection permission or connection permission based on the communication time required by the slave unit, the slave unit can quickly know whether connection is permitted or not permitted, and the received power Consumption can be reduced. Further, even a slave unit that does not support the time division multiple access method can perform data communication.
Further, according to the wireless data communication method of the slave unit of the present invention, since the slave unit transmits a connection request signal including terminal type information to the master unit, the master unit can know the terminal type of the slave unit. Therefore, it becomes possible to select a radio communication channel suitable for it.

  Hereinafter, an overall configuration of a wireless data communication system according to an embodiment of the present invention will be described with reference to FIG. FIG. 1 is a diagram showing an overall configuration of a wireless data communication system according to an embodiment of the present invention.

  In the wireless data communication system shown in FIG. 1, a master unit 1 is connected to a network 3 by a network connection interface. Wireless data transmission is performed between the slave unit 2_m (m = 1, 2, 3,..., M) and the master unit 1. The slave unit 2_m accesses the network 3 via the master unit 1.

  Master unit 1 establishes a link with slave unit 2_m, one wireless communication channel (hereinafter referred to as a link establishment channel) ChA_i (i = 1), and three dedicated channels for communicating data frames. It has a radio unit for realizing a radio communication channel (hereinafter referred to as a data communication channel) ChD_j (j = 1, 2, 3).

  The slave unit 2_m sends a connection request signal to the master unit 1 in the link establishment channel in order to connect to the master unit 1. The base unit 1 receives this connection request signal and performs connection request processing. Then, base unit 1 sends a connection request response signal to handset 2_m that has made a connection request in the link establishment channel. In addition, the slave unit 2_m sends a disconnection request signal to the master unit 1 in the link establishment channel in order to disconnect from the master unit. The base unit 1 receives this connection disconnection request signal and performs connection disconnection request processing. Then, base unit 1 transmits a connection disconnection request response signal to slave unit 2_m that has requested connection disconnection in the link establishment channel.

  However, in this embodiment, the link establishment channel uses a standard CSMA / CA (Carrier Sense Multiple Access with Collision Avoidance) system in a wireless local area network (LAN). Each data communication channel uses a TDMA (Time Division Multiple Access) system.

  Next, the configuration of the master unit configuring the wireless data communication system of FIG. 1 will be described with reference to FIG. FIG. 2 is a block diagram showing the configuration of the master unit. As shown in FIG. 2, the base unit 1 includes an initialization unit 101, a transmission / reception unit 102, a connection permission slave unit address holding unit 103, a terminal type information holding unit 104, a connection request processing unit 105, and a terminal confirmation. Means 106, selected channel holding means 107, channel selection processing means 108, connection request response signal processing means 109, connection disconnection request processing means 110, connection disconnection request response processing means 111, and data signal transmission processing means 112. And data signal reception processing means 113 and data storage means 114.

  The initialization unit 101 determines the frequency band of the link establishment channel ChA_1 and also determines the frequency bands of the three data communication channels ChD_j (j = 1, 2, 3). The initialization unit 101 also includes a total communication time zone (allocated total time) allocated to the three data communication channels ChD_j (j = 1, 2, 3) stored in the selected channel holding unit 107. TcD_j (j = 1, 2, 3) is initialized to 0. In the present embodiment, the center frequency of the frequency band of the link establishment channel is determined to be 2.412 GHz, and the center frequency of each of the three data communication channels is set to 2.437 GHz, 2.462 GHz, 2. It is determined to be 484 GHz. In the present embodiment, the frequency band of the link establishment channel and the frequency band of the data communication channel are determined to be different.

  The transmission / reception unit 102 receives information on the frequency band of the link establishment channel ChA_1 and the frequency band of each data communication channel ChD_j (j = 1, 2, 3) from the initialization unit 101. Based on the received information, the transmission / reception means 102 receives a connection request signal and a connection disconnection request signal from the slave unit 2_m, and transmits a connection request response signal and a connection disconnection request response signal to the slave unit 2_m. . Moreover, the transmission / reception means 102 transmits / receives a data signal with the subunit | mobile_unit 2_m.

  The connection permission child device address holding means 103 lists a child device address (address uniquely assigned to the child device) of the child device permitted to connect to the own device (hereinafter referred to as a connection permission child device address list). Remember.

  The terminal type information holding unit 104 holds information shown in FIG. This information will be described with reference to FIG. FIG. 3 is a diagram showing an example of information held in the terminal type information holding unit 104. In FIG. 3, for each terminal type (type A to type E), a channel access method, a transmission band, and a reception band are associated with the terminal type. For example, in the case of type D, it indicates that the slave unit performs communication by the TDMA method, and indicates that the slave unit requires a bandwidth of 64 kb / s for transmission and a bandwidth of 128 kb / s for reception. ing. In the case of type E, it indicates that the slave unit performs communication by the CSMA method. The base unit 1 transmits the connection request signal by referring to FIG. 3 based on the terminal types (type A to type E) included in the handset information in the connection request signal sent from the handset 2_m. The access method (TDMA method, CSMA method) of the original slave unit 2_m, the band required for transmission, and the band required for reception can be specified.

  The connection request processing means 105 receives the connection request signal from the transmission / reception means 102, and reads the slave unit information included in the received connection request signal. Then, the connection request processing unit 105 outputs the read slave unit information to the terminal confirmation unit 106.

  The terminal confirmation unit 106 receives the slave unit information from the connection request processing unit 105, and reads the terminal type and the slave unit address included therein from the received slave unit information. Then, the terminal confirmation unit 105 confirms whether or not the read terminal type is in the “terminal type” column of the information illustrated in FIG. 3 stored in the terminal type information holding unit 104, and the read slave unit It is confirmed whether the address is included in the connection-permitted slave unit address list stored in the connection-permitted slave unit address holding means 103. When the terminal confirmation unit 106 confirms that the read terminal type is in the “terminal type” column of FIG. 3 and that the read child device address is included in the connection permitted child device address list, The handset information is output to the channel selection processing means 108. On the other hand, the terminal confirmation means 106 confirms that the read terminal type is not in the “terminal type” column of FIG. 3, or confirms that the read handset address is not included in the connection permitted handset address list. If confirmed, connection to the base unit 1 is not permitted.

  The selected channel holding means 107 stores the channel information of each data communication channel ChD_j (j = 1, 2, 3). The channel information is assigned to the data communication channel ChD_j, the maximum value of the communication time zone (maximum allocation time) TcDmax_j, the allocated total time TcD_j of the data communication channel ChD_j, and the data communication channel ChD_j. It includes a slave unit address of each slave unit 2_m, a communication time Tc_m required by each slave unit 2_m allocated to the data communication channel ChD_j, and an offset time off_m thereof. A channel identifier ChT_m indicating the channel to which the handset 2_m is assigned to the transmission / reception means 102 is output.

  The channel selection processing unit 108 receives the slave unit information from the terminal confirmation unit 106. Then, the channel selection processing means 108 refers to the information shown in FIG. 3 held in the terminal type information holding means 104, and the channel access method corresponding to the terminal type included in the handset information is TDMA. Or CSMA.

  When it is determined that it is TDMA, the channel selection processing means 108 calculates the communication time Tc_m required by the slave unit 2_m of the slave unit address included in the slave unit information. For example, when the terminal type included in the handset information is type C, the calculation is performed as follows. The transmission band corresponding to the type C in FIG. 3 is 64 kb / s, and the reception band is 64 kb / s. Further, the transmission rate of the data communication channel is 11 Mb / s, the period of the data communication channel allocation time is 500 ms, that is, the maximum allocation time TcDmax_j (of the data communication channel ChD_j (j = 1, 2, 3)). j = 1, 2, 3) is set to 500 ms. Accordingly, the communication time Tc_m required by the child device 2_m is 5.3 ms (= (64 kb / s + 64 kb / s) / (11 Mb / s) × (500 ms)). Similarly, when the terminal type is type D, the communication time Tc_m is 8.73 ms. A fixed value may be added as a guard time to the communication time Tc_m.

  Subsequently, the channel selection processing means 108 compares the values of the allocated total time TcD_j of the three data communication channels ChD_j stored in the selected channel holding means 107, and the data communication channel having the smallest value. Is selected as a data communication channel that is permitted to be used by the slave unit 2_m. However, if there are a plurality of assigned times with the smallest total time, the one with the smallest value of j is selected. For example, when the allocated total time TcD_1 and the allocated total time TcD_2 take the minimum values, the data communication channel ChD_1 having the smaller value of j is selected.

  Subsequently, when the data communication channel ChD_t is selected, the channel selection processing means 108 determines whether the calculated communication time Tc_m required by the slave unit 2_m falls within the remaining allocation time of the data communication channel ChD_t. to decide. This determination is made by adding the allocated total time TcD_t of the data communication channel ChD_t stored in the selected channel holding means 107 and the calculated communication time Tc_m, and this added value is stored in the selected channel holding means 107. This is performed depending on whether it is equal to or shorter than the maximum allocation time TcDmax_t of the data communication channel ChD_t.

  When it is determined that the added value (TcD_t + Tc_m) is equal to or less than the maximum allocation time TcDmax_t, the channel selection processing unit 108 sets the channel identifier ChT_m as the selected data communication channel ChD_t (ChT_m = ChD_t). Then, the channel selection processing means 108 receives permission information including the TDMA communication permission, the handset address included in the handset information received from the terminal confirmation means 108, and the channel identifier ChT_m. The connection request response signal processing means To 109. Further, the channel selection processing unit 108 updates the allocated total time TcD_t by adding the calculated communication time Tc_m to the allocated total time TcD_t of the selected data communication channel ChD_t stored in the selected channel holding unit 107. (TcD_t = TcD_t + Tc_m). Further, the slave unit address of the slave unit 2_m, the communication time Tc_m, and the like are added to the channel information of the data communication channel ChD_t.

  On the other hand, when it is determined that the added value (TcD_t + Tc_m) is not less than or equal to the maximum allocation time TcDmax_t, the TDMA communication is not permitted and the disallowance including the handset address included in the handset information received from the terminal confirmation unit 108 is not permitted. Information is output to the connection request response signal processing means 109.

  If it is determined that the channel is CSMA, the channel selection processing unit 108 sets the channel identifier ChT_m as the link establishment channel ChA_1 (ChT_m = ChA_1). Then, the channel selection processing means 108 receives permission information including CSMA communication permission, the handset address included in the handset information received from the terminal confirmation means 108, and the channel identifier ChT_m. To 109. When there are a plurality of link establishment channels, the channel information requested for connection is set as a channel identifier ChT_m.

  The connection request response signal processing unit 109 receives permission information or non-permission information from the channel selection processing unit 107, and generates a connection request response signal including the received permission information or non-permission information. Then, the connection request response signal processing unit 109 outputs the generated connection request response signal to the transmission / reception unit 102.

The connection disconnection request processing unit 110 receives a connection disconnection request signal from the transmission / reception unit 102, and reads the slave unit information included therein from the received connection disconnection request signal. Then, the disconnection request processing means 110 cancels the assignment of the slave unit 2_m to the corresponding channel based on the read slave unit information (including the slave unit address and the channel identifier to be canceled).
The disconnection request processing unit 110 extracts from the selected channel holding unit 107 the allocated total time TcD_j of the data communication channel ChD_j to be deallocated and the communication time Tc_m of the slave unit 2_m. Then, the communication time Tc_m extracted is subtracted from the extracted allocated total time TcD_j to update the allocated total time TcD_j (TcD_j = TcD_j−Tc_m).
Note that information related to the slave unit 2_m is deleted from the channel information of the data communication channel to be deallocated stored in the channel selection holding means 107.
The disconnection request processing unit 110 outputs the slave unit information to the disconnection request response processing unit 111.

  The disconnection request response processing means 111 receives the slave unit information from the disconnection request processing unit 110 and generates a disconnection request response signal including the received slave unit information. Then, the disconnection request response processing unit 111 outputs the generated disconnection request response signal to the transmission / reception unit 102.

  The data signal transmission processing unit 112 generates a data signal from the data, and outputs the generated data signal to the transmission / reception unit 102. The data signal reception processing unit 113 receives the data signal from the transmission / reception unit 102 and generates data from the received data signal. The data storage unit 114 stores data.

  Further, the state transition of the above-described base unit will be described with reference to FIG. FIG. 4 is a state transition diagram of the master unit.

  In the initial state STA1, the initialization unit 101 of the base unit 1 uses the center frequency of the frequency band of the link establishment channel ChA_i (i = 1) and the three data communication channels ChD_j (j = 1, 2, 3). The center frequency of each frequency band is determined. At the same time, the initialization unit 101 calculates the allocated total time TcD_j (j = 1, 2, 3) of each data communication channel ChD_j (j = 1, 2, 3) stored in the selected channel holding unit 107. Initialize to 0. Thereafter, the mobile device connection waiting state STA2 is entered.

  In the handset connection waiting state STA2, the base unit 1 monitors the channel establishment channel ChA_i (i = 1), and a connection request signal sent from the handset 2_m or a connection disconnection request signal sent from the handset 2_m. Waiting for reception of the device enters a reception waiting state. In this reception waiting state, when a connection request signal is received, a transition is made to the slave unit confirmation state STA3, and when a connection disconnection request signal is received, a transition is made to the slave unit disconnection state STA9.

  In the child device confirmation state STA3, the terminal confirmation means 106 of the parent device 1 confirms whether the terminal type included in the child device information in the received connection request signal is in the “terminal type” column of FIG. Check whether the slave unit address included in the unit information is included in the connection permitted slave unit address list. It is confirmed that the terminal type included in the handset information is in the “terminal type” column of FIG. 3, and the handset address included in the handset information is included in the connection permitted handset address list. If it is confirmed, it is determined whether the access channel method corresponding to the terminal type is TDMA or CSMA. If it is TDMA, transition is made to the TDMA handset bandwidth allocation state STA4, and if it is CSMA, transition is made to the CSMA connection state STA8. On the other hand, it is confirmed that the terminal type included in the handset information is not in the “terminal type” column of FIG. 3, or the handset address included in the handset information is added to the connection permitted handset address list. When it is confirmed that it is not included, the connection to the parent device 1 of the child device 2_m that has transmitted the connection request signal is not permitted, and the state shifts to the child device connection waiting state STA2.

  In the TDMA slave unit bandwidth allocation state STA4, the channel selection processing means 108 of the master unit 1 calculates the communication time Tc_m required by the slave unit 2_m that has transmitted the connection request signal according to the procedure described above. Thereafter, the state transits to the time division multiple access channel selection state STA5.

  In the time division multiple access channel selection state STA5, the channel selection processing unit 108 of the base unit 1 selects one data communication channel from the three data communication channels ChD_j (j = 1, 2, 3) according to the procedure described above. select. Then, if the data communication channel ChD_t is selected, the channel selection processing means 108 determines whether the calculated communication time Tc_m required by the slave unit 2_m falls within the remaining allocation time of the data communication channel ChD_t (added value) (TcD_t + Tc_m) is less than or equal to the maximum allocation time TcDmax_t). When it is determined that it does not fit, the state shifts to the time division multiple access connection state STA6, and when it is determined that it does not fit, the state shifts to the connection request response state STA7 when the bandwidth is insufficient.

  In the time division multiple access connection state STA6, the channel selection processing means 108 of the base unit 1 sets the channel identifier ChT_m as the selected data communication channel ChD_t (ChT_m = ChD_t). Then, base unit 1 sends a connection request response signal including permission information including TDMA communication permission, handset address, and channel identifier ChT_m to handset 2_m that has transmitted the connection request signal, to channel establishment channel ChA_i (i = 1). Further, the base unit adds the calculated communication time Tc_m to the allocated time TcD_t of the data communication channel ChD_t to update the allocated time TcD_t. Thereafter, the mobile device transitions to a handset connection waiting state STA2. Receiving this connection request response signal, the slave unit 2_m communicates data using the data communication channel of the channel identifier ChT_m included therein.

  In the connection response state STA7 when the band is insufficient, the base unit 1 links a connection request response signal including non-permission information including TDMA communication disapproval and a sub unit address to the sub unit 2_m that has transmitted the connection request signal. It is transmitted on the establishment channel ChA_i (i = 1). Thereafter, the mobile device transitions to a handset connection waiting state STA2. Receiving the connection request response signal, the slave unit 2_m can know that the connection is not permitted.

  In the CSMA connection state STA8, the channel selection processing means 108 of the base unit 1 sets the channel identifier ChT_m as the channel establishment channel ChA_1 (ChT_m = ChA_1). Then, base unit 1 sends a connection request response signal including permission information including CSMA communication permission, handset address, and channel identifier ChT_m to handset 2_m that has transmitted the connection request signal. = 1). Thereafter, the mobile device transitions to a handset connection waiting state STA2. Receiving this connection request response signal, handset 2_m communicates data using a channel establishment channel with channel identifier ChT_m included therein.

In the slave unit connection disconnection state STA9, the connection disconnection request processing means 110 of the master unit 1 cancels the assignment of the slave unit 2_m to the corresponding channel based on the slave unit information in the connection disconnection request signal.
The disconnection request processing means 110 updates the allocated total time TcD_j by subtracting the communication time Tc_m of the slave unit 2_m from the allocated total time TcD_j of the data communication channel ChD_j to be deallocated. Then, base unit 1 transmits a connection disconnection request response signal to link establishment channel ChA_i (i = 1) to slave unit 2_m that has transmitted the connection disconnection request signal. Thereafter, the mobile device connection waiting state STA2 is entered. This connection disconnection request response signal is received by the slave unit 2_m.

Hereinafter, examples of the above-described embodiment will be shown. FIG. 5 is a diagram illustrating an example of the embodiment.
When the base unit 1 receives the connection request signal including the type C from the slave unit 2_3, since the allocated total time TcD_3 of the data communication channel ChD_3 is the minimum at that time, the master unit 1 performs data communication with the slave unit 2_3. Assigned to the channel ChD_3. Then, base unit 1 transmits a connection request response signal (permission) including channel identifier ChT_3 indicating data communication channel ChD_3 to slave unit 2_3. The subunit | mobile_unit 2_3 receives a connection request response signal (permission), and communicates data by channel ChD_3 for data communication which channel identifier ChT_3 contained in it contains. Note that substantially the same is performed in the connection request signal including the type E received later from the slave unit 2_6.

  When the master unit 1 receives a connection request signal from an unauthorized slave unit, the master unit 1 does not allocate or respond to the channel. When the master unit 1 receives the connection disconnection request signal from the slave unit 2_4, the master unit 1 releases the assignment of the slave unit 2_4 to the data communication channel ChD_2 and sends a disconnection request response signal to the slave unit 2_4. .

  When the base unit 1 receives the connection request signal including the type E from the handset 2_6, the base unit 1 assigns the handset 2_6 to the link establishment channel ChA_1. Then, base unit 1 sends a connection request response signal (permission) including channel identifier ChT_6 indicating link establishment channel ChA_1 to slave unit 2_6. The subunit | mobile_unit 2_6 receives a connection request | requirement response signal, and communicates data by the channel for channel establishment which the channel identifier ChT_6 contained in it contains.

  As described above, according to this embodiment, since channel scheduling is effective, effective use of bandwidth can be achieved. Further, even when the slave unit does not support the time division multiple access method, data communication can be performed. Furthermore, since the parent device calculates the communication time required by the child device, determines whether or not connection is possible, and notifies the child device of connection permission or connection disapproval, as shown in FIG. In both cases of connection permission and connection disapproval, the time for waiting for connection permission for a connection request can be shortened. As a result, it is possible to obtain an effect that the power consumption of the receiving circuit of the slave unit can be suppressed. 6 (a) and 6 (b) show conventional ones, and FIG. 6 (c) shows the present embodiment.

  In addition, since it is not necessary to perform carrier sense in order to perform data communication, the bandwidth of the data communication channel can be used effectively. Furthermore, since the standardized CSMA / CA method is used, development costs can be reduced. Further, the selection of the data communication channel can be realized by a simple method.

  The preferred embodiments of the present invention have been described above. However, the present invention is not limited to the above-described embodiments, and various design changes can be made as long as they are described in the claims. For example, in the above embodiment, as means for disconnecting the slave unit from the master unit, a connection disconnection request signal and a disconnection request response signal for the connection unit are transmitted. However, the present invention is not limited to this. The data signal from the slave unit may be monitored, and if the data signal from the slave unit does not exist for a certain period, the connection from the slave unit may be prohibited.

  In the above embodiment, there is one link establishment channel and three data communication channels. However, the present invention is not limited to this, and there are Na (Na is a natural number) number of link establishment channels (the channel to be used is For example, it may be selected at random) and Nd (Nd is a natural number) data communication channels.

  Furthermore, in the above embodiment, the frequency band for the link establishment channel and the data communication channel is different, but the present invention is not limited to this. For example, the frequency band of the link establishment channel is used for data communication. The same frequency band as the channel may be used, and the base unit may logically include a link establishment channel and a data communication channel as channels for time division multiple access communication. An example of this is shown in FIG. 7, which shows that one link establishment channel and one data communication channel are provided periodically.

  In the above embodiment, the CSMA / CA method for performing carrier sense is used as a method for communication on the link establishment channel. However, the present invention is not limited to this, and a time division multiple access method may be used. . Moreover, you may use the radio channel access system which performs another carrier sense. Furthermore, other wireless communication channel access methods may be used.

  Furthermore, in the above embodiment, as a method for selecting one data communication channel from a plurality (three in the embodiment) of data communication channels, the data communication channel with the smallest allocated total time is selected. This is the case when using the method. However, not limited to this, select one randomly from a plurality of data communication channels, and select this when the communication time required by the slave unit falls within the remaining allocated time of the selected data communication channel. If it does not fit, a method of excluding this and selecting one again may be used. Note that the number of re-selections may be finite. Alternatively, a method of selecting one from a plurality of data communication channels according to a predetermined order may be used.

  If there are a plurality of link establishment channels, the channels can be selected as follows. This will be described with reference to FIG. FIG. 8 shows a time chart of two link establishment channels and two data communication channels. In the case of FIG. 8, one channel establishment channel and one data communication channel are realized in one frequency band, and a total of two frequency bands are used.

The master unit senses each channel and monitors the usage rate of each channel. Here, the data frame transmitted and received by the master unit is excluded from the usage rate. That is, the usage rate is the ratio of noise that occupies other than the data frame period transmitted and received by the master unit. For example, in the slot S of FIG. 8, the usage rate is as follows.
Usage rate = Tn_1_1 / (TcDmax_1-Tc_1-Tc_2)
The master unit takes the average of the calculation results for each link establishment channel and each data communication channel, and assigns the slave unit to the channel with the lowest usage rate, based on the terminal type. Thereby, the data communication of the slave unit can be permitted to the channel with little noise, and the loss of the data frame due to the noise can be prevented in advance. In addition, although the method of calculating the usage rate is illustrated as a method for selecting a channel permitting data communication, this is used as a method for selecting a channel for establishing a link when a slave unit transmits a connection request signal. Also good. Other channel selection methods may be used.

  Note that a program for realizing the functions of the processing units of the master unit and the slave unit described above is recorded on a computer-readable recording medium, and the program recorded on the recording medium is read into a computer system and executed. The above processing may be performed as necessary. The “computer system” here includes an OS and hardware such as peripheral devices. The “computer system” includes a WWW system having a homepage providing environment (or display environment). The “computer-readable recording medium” refers to a storage device such as a flexible medium, a magneto-optical disk, a portable medium such as a ROM and a CD-ROM, and a hard disk incorporated in a computer system. Further, the “computer-readable recording medium” refers to a volatile memory (RAM) in a computer system that becomes a server or a client when a program is transmitted via a network such as the Internet or a communication line such as a telephone line. In addition, those holding programs for a certain period of time are also included.

  The program may be transmitted from a computer system storing the program in a storage device or the like to another computer system via a transmission medium or by a transmission wave in the transmission medium. Here, the “transmission medium” for transmitting the program refers to a medium having a function of transmitting information, such as a network (communication network) such as the Internet or a communication line (communication line) such as a telephone line. The program may be for realizing a part of the functions described above. Furthermore, what can implement | achieve the function mentioned above in combination with the program already recorded on the computer system, and what is called a difference file (difference program) may be sufficient.

The figure which shows the whole structure of the radio | wireless data communication system in embodiment of this invention. The block diagram which shows the structure of the main | base station of FIG. The figure which shows an example of the information hold | maintained at the terminal classification information holding means of FIG. The state transition diagram of the main | base station of FIG. FIG. 6 illustrates an example of an embodiment. The figure for demonstrating the effect of Embodiment. The figure for demonstrating a modification (the 1). The figure for demonstrating a modification (the 2).

Explanation of symbols

1 master unit, 2_1 to 2_M slave unit 101 initialization unit, 102 transmission / reception unit, 103 connection permission slave unit address holding unit, 104 terminal type information holding unit, 105 connection request processing unit, 106 terminal confirmation unit, 107 selection channel holding unit , 108 channel selection processing means, 109 connection request response signal processing means, 110 connection disconnection request processing means, 111 connection disconnection request response processing means, 112 data signal transmission processing means, 113 data signal reception processing means, 114 data storage means

Claims (8)

In a wireless communication channel selection method in a wireless data communication system in which a parent device is connected to a network, wirelessly transmits data between the child device and the parent device, and the child device accesses the network via the parent device,
Using a first wireless communication channel group including one or more wireless communication channels and a second wireless communication channel group including one or more wireless communication channels for a time division multiple access method;
The slave unit transmits a connection request signal to the master unit via any one of the wireless communication channels of the first wireless communication channel group,
The base unit is
Whether to receive the connection request signal from the slave unit and whether the slave unit communicates by a time division multiple access method based on terminal type information included in the connection request signal or by another wireless access method Judging
When it is determined that communication is performed by the time division multiple access method, the communication time required by the slave unit is determined based on the terminal type information included in the connection request signal from the slave unit,
Selecting one wireless communication channel from the second wireless communication channel group according to a predetermined selection method;
Determining whether the determined communication time falls within the remaining allocated time of the selected wireless communication channel;
A connection including information on the selected wireless communication channel when it is determined that the communication time is within the remaining allocated time for the slave in any wireless communication channel of the first wireless communication channel group A first connection request response signal of permission is transmitted, and when it is determined that the communication time does not fall within the remaining allocated time, a second connection request response signal of permission of connection is transmitted;
When it is determined that communication is performed using another wireless access method, one wireless communication in the first wireless communication channel group is transmitted to the slave unit in any wireless communication channel of the first wireless communication channel group. Transmitting a connection permission third connection request response signal including channel information;
When the slave unit receives the first connection request response signal from the master unit, the slave unit communicates data through the wireless communication channel included in the first connection request response signal, and the master unit transmits the third connection request. When a response signal is received, data is communicated using the wireless communication channel included in the third connection request response signal.
A radio channel selection method characterized by the above.   2. The wireless communication channel selection method according to claim 1, wherein the selection method is to select a wireless communication channel having a minimum total time allocated from the second wireless communication channel group.   The selection method randomly selects one wireless communication channel from the second wireless communication channel group, and selects this when the determined communication time falls within the remaining allocated time of the selected wireless communication channel The method of selecting a wireless communication channel according to claim 1, wherein if the result does not fit, the selection is made again by excluding it.   2. The radio communication channel selection method according to claim 1, wherein the selection method is to select one radio communication channel from the second radio communication channel group in a predetermined order.   The wireless communication channel selection method according to any one of claims 1 to 4, wherein a carrier sensing scheme is used in the first wireless communication channel group.   The wireless communication channel selection method according to any one of claims 1 to 4, wherein the first wireless communication channel group uses a CSMA / CA scheme. In a wireless communication channel selection method of a parent device in a wireless data communication system in which a parent device is connected to a network, wirelessly transmits data between the child device and the parent device, and the child device accesses the network via the parent device. ,
Using a first wireless communication channel group including one or more wireless communication channels and a second wireless communication channel group including one or more wireless communication channels for a time division multiple access method;
A connection request signal is received from the slave unit, and whether the slave unit communicates by a time division multiple access method or another wireless access method based on terminal type information included in the connection request signal Judgment
When it is determined that communication is performed by the time division multiple access method, the communication time required by the slave unit is determined based on the terminal type information included in the connection request signal from the slave unit,
Selecting one wireless communication channel from the second wireless communication channel group according to a predetermined selection method;
Determining whether the determined communication time falls within the remaining allocated time of the selected wireless communication channel;
A connection including information on the selected wireless communication channel when it is determined that the communication time is within the remaining allocated time for the slave in any wireless communication channel of the first wireless communication channel group A first connection request response signal of permission is transmitted, and when it is determined that the communication time does not fall within the remaining allocated time, a second connection request response signal of permission of connection is transmitted;
When it is determined that communication is performed using another wireless access method, one wireless communication in the first wireless communication channel group is transmitted to the slave unit in any wireless communication channel of the first wireless communication channel group. Transmitting a connection permission third connection request response signal including channel information;
A radio channel selection method for a master unit. In the wireless data communication method of the slave unit in the wireless data communication system in which the master unit is connected to the network, performs wireless data transmission between the slave unit and the master unit, and the slave unit accesses the network via the master unit,
Using a first wireless communication channel group including one or more wireless communication channels and a second wireless communication channel group including one or more wireless communication channels for a time division multiple access method;
The slave unit communicates with the slave unit by a time division multiple access method or other access method,
A connection request signal including terminal type information is transmitted to the master unit in any one of the first wireless communication channel groups;
Receiving a response to the connection request signal from the base unit, and communicating data on one of the wireless communication channels based on the response;
A wireless data communication method for a slave unit.

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