JP2008072535A - Communication method, radio communication terminal, and radio communication system for radio network - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a communication method, a radio communication terminal and a radio communication system for a radio network capable of effectively reducing the total amount of signals. <P>SOLUTION: In the communication method for transmitting/receiving data by a signal for data communication in the radio network and transmitting a signal for control to all the terminals in the surroundings at predetermined intervals, it is characterized that the signal for control and the signal for data communication are stored in a single packet and destination addresses of the respective signals are stored in the packet to be transmitted in transmission of the signal for control. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a communication method in a wireless network, a wireless communication terminal, and a wireless communication system having the wireless communication terminal.

Conventionally, as a technique related to a communication method in a wireless network, “control for wireless transmission from its own station when periodically transmitting control information including identification information of its own station to other wireless communication devices in the wireless network” It is notified by the information that transmission of the control information is to be stopped, and after the notification, control for stopping transmission of the control information for a predetermined period is performed. As a result, the transmission of control information is stopped for a predetermined period after the peripheral station of the local station knows that the transmission of control information is stopped. It will be known beforehand that it will not be transmitted. (Patent Document 1). This is to reduce the overall signal amount by omitting part of the periodic transmission of control signals.
In addition, as the structure of the wireless network, a broadcast packet is periodically transmitted in order to notify the existence of a wireless LAN access point to the surrounding area (Non-patent Document 1), There is one that takes a hierarchical structure to be managed and periodically transmits the operation status to the management terminal in a unicast packet (Non-Patent Document 2).

Japanese Patent Laying-Open No. 2005-45616 (Summary) Information technology-Telecommunications and indormation exchange between systems-Local and metropolitan area networks-Specific requirements-Part 11: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) Specifications, LAN MAN Standards Committee of the IEEE Computer Society, 1999 Zigbee Specification, Zigbee Alliance, 2005

In the above prior art, the control signal and the data communication signal usually have different destinations, and are therefore handled separately. For this reason, the total signal amount is the sum of both, and the amount of communication tends to increase as the number and density of wireless communication terminals increase.
Therefore, a communication method, a wireless communication terminal, and a wireless communication system in a wireless network that can effectively reduce the overall signal amount have been desired.

A communication method in a wireless network according to the present invention includes:
A communication method in a wireless network, in which data is transmitted / received by a data communication signal and a control signal is transmitted to all peripheral terminals at a predetermined interval,
When sending a control signal,
Put control signal and data communication signal in a single packet,
The destination address of each signal is stored in the packet and transmitted.

According to a communication method in a wireless network according to the present invention,
The total signal amount of the control signal and the data communication signal can be effectively reduced, and collision between signals can be reduced.

Embodiment 1 FIG.
FIG. 1 shows a configuration example of a wireless network according to the first embodiment.
In FIG. 1, a wireless communication terminal 101 performs wireless communication with other wireless communication terminals 101 existing in the vicinity. A line connecting the wireless communication terminals 101 indicates that the connected terminals can perform wireless communication.
In addition, the wireless communication terminals 101 synchronize with each other by transmitting and receiving control signals to and from each other. The double-headed arrows in FIG. 1 indicate how control signals are transmitted and received.
However, FIG. 1 does not show transmission / reception of all control signals, but shows only a part thereof.

  Here, a communication method in a conventional wireless network will be described with reference to FIG.

Since the purpose of the control signal is to synchronize all the wireless communication terminals 101, as shown in FIG. 1, the control signal is transmitted to the peripheral wireless communication terminals 101 by a method of performing batch transmission such as multicast or broadcast. The
An example of the control signal is a signal used for managing a routing table.
In this case, when the wireless communication terminal 101 receives a packet including a control signal, the wireless communication terminal 101 updates a table (routing table) managing peripheral terminals.
When a packet including a control signal is not received continuously for a predetermined time, it is determined that the terminal is abnormal or the communication path between terminals is disconnected, and the entry of the terminal is deleted from the routing table.
Also, the routing table is updated according to the connection status with peripheral terminals.

On the other hand, the data communication signal is normally unicast transmitted to the destination wireless communication terminal 101.
The data communication signal here is a signal mainly for transmitting / receiving application data and the like for use by the user, and is different in use and destination from the control signal for internal control of the wireless communication terminal 101. It is normal.
Therefore, the control signal and the data communication signal are transmitted and received separately.

Then, the total signal amount increases due to the sum of the control signal and the data communication signal, and the communication amount tends to increase as the number and density of wireless communication terminals increase. It becomes easy to get up.
Therefore, the present invention proposes a communication method for transmitting a control signal and a data communication signal in a single packet.

  Hereinafter, a specific configuration of the communication method and the wireless communication terminal 101 according to the first embodiment will be described.

FIG. 2 shows the configuration of radio communication terminal 101 in the first embodiment.
2 includes an antenna 201, a reception circuit 202, a transmission circuit 203, a reception data processing unit 204, a transmission data generation unit 205, and a control signal management unit 206.
The antenna 201 is an antenna for transmitting and receiving a radio signal, outputs the received radio signal to the reception circuit 202, and transmits the radio signal output from the transmission circuit 203.
The reception circuit 202 processes the radio signal input from the antenna 201, converts it into digital information, and outputs it to the reception data processing unit 204 as reception data.
The reception data processing unit 204 processes the reception data output from the reception circuit 202, performs necessary processing, outputs a control signal to the control signal management unit 206, and transmits a data communication signal to the transmission data generation unit 205. Output to. Details will be described later.
The transmission circuit 203 converts the transmission data generated by the transmission data generation unit 205 into a signal used for wireless communication, and outputs the signal to the antenna 201.
The transmission data generation unit 205 generates transmission data to be transmitted from the antenna 201 based on the data output from the reception data processing unit 204, the data output from the control signal management unit 206, or the data generated by itself.
The control signal management unit 206 generates data necessary for transmitting the control signal at predetermined intervals and outputs the data to the transmission data generation unit 205.

Next, a detailed operation of the transmission data generation unit 205 will be described.
The transmission data generation unit 205 generates transmission data triggered by receiving data necessary for transmitting a control signal from the control signal management unit 206.
That is, the transmission data is generated at the same interval as the control signal management unit 206 generates data necessary for transmitting the control signal.
When a transmission request for a data communication signal is generated when the control signal management unit 206 does not generate data, the transmission data generation unit 205 transmits the data communication signal until the control signal management unit 206 generates data. Wait without sending.

FIG. 3 shows the format of the communication packet of wireless communication terminal 101 in the first embodiment.
The transmission data generation unit 205 generates transmission data according to the format of FIG.
The packet format in FIG. 3 is divided into a part for storing data related to the control signal (control signal part) and a part for storing data related to the data communication signal (data communication signal part). A predetermined boundary identification code is inserted at the boundary between the two, whereby each portion is identified.

(Configuration of control signal part)
The control signal portion includes (1) a control signal destination address (Destination address), (2) a control signal source address (Source address), and (3) control signal main body data (Beacon payload). It is.
(1) Destination address As the destination address, all addresses of the wireless communication terminal 101 existing in the vicinity, that is, a broadcast address (for example, 0xffff) is designated.
Instead of specifying the broadcast address, multicast specification including all the wireless communication terminals 101 existing in the vicinity may be used.
(2) Source address The source address is the address of the wireless communication terminal 101 that transmitted the packet.
(3) Control signal main body data The control signal main body data is data corresponding to the content of control performed by the control signal.

(Configuration of signal part for data communication)
The data communication signal part includes (1) a MAC layer destination address (MAC Destination address) of the data communication signal, (2) a MAC layer transmission source address (MAC Source address) of the data communication signal, and (3) data communication. Network layer destination address (NWK Destination address) of the signal for signal, (4) network layer transmission source address (NWK Source address) of the signal for data communication, and (5) signal main body data (Data payload) for data communication.
The configuration of the data communication signal portion is basically the same as that of the control signal portion, but the destination address and the transmission source address include both the MAC layer address and the network layer address, respectively.
This is because in the case of a signal for data communication, the final destination address is different from the terminal that received the signal, and packet transfer may be involved.
In the case of a control signal, since it is a signal that should be received by all peripheral terminals, it is not related to packet transfer, and it is not necessary to provide both MAC layer and network layer address fields.
When a plurality of data communication signal parts are included, the part after the boundary identification code may be repeated as necessary.
Details of the packet transfer will be described later with reference to FIG.

FIG. 4 is a diagram for explaining how packets transferred by the wireless communication terminal 101 are transferred.
101A to 101C are wireless communication terminals having the configuration of FIG.
The set of (network address, MAC address) of each wireless communication terminal is wireless communication terminal 101A = (A, a), wireless communication terminal 101B = (B, b), and wireless communication terminal 101C = (C, c). is there.
The wireless communication terminal 101A is connected to the wireless communication terminal 101B, and the wireless communication terminal 101B is connected to the wireless communication terminal 101C.
Here, consider a scene in which the wireless communication terminal 101A attempts to transmit a data communication signal to the wireless communication terminal 101C.

(Step 1)
The wireless communication terminal 101A transmits the data communication signal in the same packet in accordance with the transmission of the control signal.
At this time, the address of the wireless communication terminal 101C, which is the final receiving terminal, is stored in the network layer destination address column of the data communication signal portion. Further, the address of the wireless communication terminal 101A is stored in the network layer transmission source address column.
Further, since there is no route for directly connecting the wireless communication terminal 101A to the wireless communication terminal 101C, the address of the wireless communication terminal 101B is stored in the MAC layer destination address, and the address of the wireless communication terminal 101A is stored in the MAC layer transmission source address. Is stored.
Each address of the MAC layer is acquired by referring to a routing table (not shown).

(Step 2)
The wireless communication terminal 101B receives the packet transmitted from the wireless communication terminal 101A.
The control signal portion is appropriately processed according to the data content.
For the data communication signal portion, the network layer destination address is not B, so the packet is transferred with reference to a routing table (not shown).
At this time, the address of the wireless communication terminal 101C as the transfer destination is stored in the network layer destination address column of the data communication signal portion.
The MAC layer destination address stores the address of the wireless communication terminal 101C as the transfer destination, and the MAC layer transmission source address stores the address of the wireless communication terminal 101B.

  Note that the packet transmitted by the wireless communication terminal 101B in step 2 reaches the wireless communication terminal 101A that exists within the communicable range as a wireless signal, but the MAC layer destination address is “c”. The communication terminal 101A can determine that the packet is not addressed to itself and discard it.

  As described above, even if the control signal and the data communication signal are stored in a single packet and transmitted / received, if the destination address of each signal is set appropriately, the data transfer to the final destination is performed by packet transfer. Signal can be delivered.

Note that, in order to appropriately process a received packet including a plurality of destination addresses as described above, it is necessary to divide received data for each destination address and individually process the received data.
The reception data processing unit 204 plays a role in dividing the reception data, and performs the division processing based on the boundary identification code shown in FIG.
In addition, the transmission data generation unit 205 plays a role in the processing of each signal portion for data communication.
When there are a plurality of signal portions for data communication, the above step 2 is repeatedly executed according to the number and the destination address.

  Note that when receiving the data communication signal, only the destination address portion may be received first, and the payload portion may be received only when the destination is addressed to the own terminal.

FIG. 5 illustrates another example of transfer of a packet transmitted by the wireless communication terminal 101.
In FIG. 4, the wireless communication terminal 101B transfers the data communication signal portion to the wireless communication terminal 101C. At this time, the wireless communication terminal 101B does not transfer the packet until the wireless communication terminal 101B itself transmits a control signal. Alternatively, the control signal and the data communication signal to be transferred may be stored in a single packet and transmitted.
In this case, the packet transfer is performed in the following order.

(Step 1)
This is the same as step 1 in FIG.
(Step 2)
The wireless communication terminal 101B waits without transferring the data communication signal portion until its control signal management unit 206 generates data necessary for transmitting the control signal.
(Step 3)
The wireless communication terminal 101B transmits the control signal transmitted by itself and the data communication signal transferred to the wireless communication terminal 101C in a single packet to the wireless communication terminal 101C.
Note that the addresses of the MAC layer and the network layer of the data communication signal portion are the same as in the case of FIG.

In this Embodiment 1, since it waits without transmitting the signal for data communication until the transmission timing of the signal for control, it is effective in the situation where the request | requirement to the communication delay regarding data communication is not severe. If it is functional and communication delay is not allowed, it becomes necessary to take another communication method.
In addition, since the control signal and the data communication signal are transmitted in a single packet, the upper limit of the packet size may be reached due to a large amount of data communication.

In consideration of such a case, for example, the following determination function may be added to the transmission data generation unit 205.
(1) From the amount of information in the data communication signal, it is determined whether the control signal and the data communication signal can be contained in a single packet.
(2) From the information amount of the data communication signal, it is determined whether or not a signal amount reduction effect can be expected.
(3) It is determined whether or not the transmission delay of the data communication signal can be permitted from the content of the data included in the data communication signal and the remaining time until the next transmission of the control signal.
The determination functions (1) to (3) can be added in the same manner in the following embodiments.

As described above, according to the first embodiment, when a control signal is transmitted, the control signal and the data communication signal are stored in a single packet, and the destination address of each signal is stored in the packet. So send
The total signal amount of the control signal and the data communication signal can be effectively reduced, and collision between signals can be reduced.

Embodiment 2. FIG.
In the first embodiment, the configuration has been described in which the control signal is transmitted to the peripheral terminals at predetermined intervals, and the data communication signal is transmitted in the same packet.
In the second embodiment of the present invention, a configuration for reducing the overall signal amount in a situation where it is not necessary to transmit a control signal at predetermined intervals will be described.

FIG. 6 shows the configuration of radio communication terminal 101 in the second embodiment.
The basic configuration is the same as that of FIG. 2 of the first embodiment, except for the following points.
The control signal management unit 606 does not generate data necessary for the control signal at a predetermined interval, but generates data only when there is a request from the transmission data generation unit 605.
The transmission data generation unit 605 has a function of requesting the control signal management unit 606 for data necessary for the control signal.

In the second embodiment, in order to assume a situation where it is not necessary to send a control signal at a predetermined interval, the control signal management unit 606 needs data for the control signal only when requested as described above. It is enough to generate
As an example, it is conceivable that the control signal is used to check the normal operation of the peripheral terminals and to grasp the status of the communication path between the terminals. Under such circumstances, it is not necessary to periodically transmit the control signal, but if necessary, an upper limit is set on the transmission interval of the control signal to prevent a situation in which the control signal is not transmitted at all. You can also.

Next, the operation of radio communication terminal 101 in the second embodiment will be described.
When the data communication signal is generated in the reception data processing unit 604 or itself, the transmission data generation unit 605 requests the control signal management unit 606 for data necessary for the control signal.
The control signal management unit 606 generates and outputs data necessary for the control signal in response to a request from the transmission data generation unit 605.
The contents of the packet are the same as in the first embodiment.
With this configuration, since the control signal can be transmitted when a transmission request for the data communication signal is generated, the opportunity to periodically transmit the control signal can be reduced, and the overall signal amount can be reduced. Can be reduced.

In addition, when setting an upper limit for the transmission interval of the control signal, the following configuration is adopted.
(1) First, storage means such as a RAM for storing the upper limit value is provided.
(2) The elapsed time after transmitting the control signal is counted by the internal clock of the wireless communication terminal 101 and stored in the storage means.
(3) When the control signal is transmitted together with the data communication signal, the elapsed time is reset. The reset operation may be performed by the transmission data generation unit 605 or the control signal management unit 606.
(4) When the upper limit is reached without transmitting the control signal, the control signal is exceptionally transmitted alone.

Furthermore, if the time elapsed since the last transmission of the control signal has not passed at the time of transmission of the data communication signal, the data communication signal is transmitted alone without adding the control signal. It can also be configured as follows.
With this configuration, the amount of signal can be further reduced by the amount of transmission opportunities for the control signal.

  In the second embodiment, the elapsed time from the previous transmission of the control signal is counted. On the contrary, the remaining time up to the upper limit of the transmission interval of the control signal is counted. Even if it is configured as described above, the same effect can be obtained.

As described above, according to the second embodiment, when a transmission request for a data communication signal is generated, the control signal and the data communication signal are stored in a single packet, and the destination address of each signal is stored in the packet. Because we store and send
As in the first embodiment, the overall signal amount including the control signal and the data communication signal can be effectively reduced, and collision between signals can be reduced.
In particular, in a situation where it is not necessary to send a control signal at a predetermined interval, the transmission frequency of the control signal can be effectively reduced in an environment where the transmission frequency of the data communication signal is high.

In addition, storage means for storing the elapsed time from the previous transmission of the control signal and the upper limit value of the transmission interval of the control signal is provided, and when the upper limit value has elapsed from the previous transmission time of the control signal, The control signal is transmitted alone, and when the data communication signal is transmitted, the elapsed time stored in the storage means is reset.
When the transmission frequency of the data communication signal is low, it is possible to prevent a situation in which the control signal is not transmitted at all.

In addition, referring to the elapsed time stored in the storage means, only when the elapsed time is a predetermined value or more, the control signal is included in the packet.
The amount of signal can be further reduced by the amount of transmission opportunities for control signals.

Embodiment 3 FIG.
In the first and second embodiments, the configuration for reducing the overall signal amount in the wireless network that transmits the control signal to all peripheral terminals has been described.
In Embodiment 3 of the present invention, a configuration for reducing the overall signal amount in a wireless network having a hierarchical structure in which some terminals manage other terminals will be described.
Note that the configuration of the wireless communication terminal in the third embodiment is the same as that in FIG.

FIG. 7 shows a configuration example of a wireless network in the third embodiment.
In FIG. 7, each wireless communication terminal manages network connections according to a hierarchical relationship on a tree with the parent terminal 701A as a management terminal. Terminals other than the parent terminal 701A are called child terminals.
The thick line in FIG. 7 represents the management hierarchy relationship of each wireless communication terminal with the parent terminal 701A as the root of the tree.
In addition, the broken line connecting the wireless communication terminals indicates that the connected terminals are not in a management hierarchy relationship but can be wirelessly communicated with each other because they are within the reach of the wireless signal. ing.
In the wireless network of FIG. 7, when the distance between the terminals is close, the wireless signal may actually arrive. However, the transmission / reception of the control signal always has a hierarchical relationship represented by a bold line. Communication takes place along the route.

The lower diagram in FIG. 7 shows how packets are transferred.
In FIG. 7, when a data communication signal packet is transmitted from the transmission source terminal to the destination terminal, the packet is once transmitted to the parent terminal 701A, and the packet is transferred from the parent terminal 701A to the destination terminal. A more detailed description will be given later in FIG.

Here, it is normal that the control signal and the data communication signal are transmitted separately, but if the transmission directions of both signals (directions indicated by arrows in FIG. 8) coincide with each other, Similarly, both can be sent in a single packet.
In this case, as in the first embodiment, the data communication signal can be stored in the same packet and transmitted together with the control signal periodically transmitted at a predetermined interval.
The terminal that receives the packet may receive only the signal addressed to itself, as in the first embodiment, and transfer other signals to other terminals.
By configuring in this way, a signal amount reduction effect can be expected as in the first embodiment.

FIG. 8 shows a communication packet format of wireless communication terminal 701 in the third embodiment.
The basic configuration is the same as that in FIG. 3 of the first embodiment, except that a beacon destination address (Beacon Destination) is added to the control signal portion.
(1) Destination address (Destination address)
A broadcast address (for example, 0xffff) is designated as the destination address of the control signal portion.
Instead of designating the broadcast address, multicast designation including at least both the control signal destination and the data communication signal destination may be used.
(2) Beacon destination address In the beacon destination address, the address of the parent terminal 701A that is the destination of the control signal is specified.

FIG. 9 shows how packets are transferred in the third embodiment. In the following, description will be given in order.
(1)
In FIG. 9, the transmission source terminal 701C intends to transmit a data communication signal to the destination terminal 701D via the parent terminal 701A.
(2)
At this time, the transmission source terminal 701C stands by without transmitting the data communication signal until the timing for transmitting the control signal to the parent terminal 701A.
(3)
When transmitting the control signal, a transmission packet is created in the packet format of FIG. 8 and transmitted to the parent terminal 701A.
The address of the destination terminal 701D, which is the final receiving terminal, is stored in the network layer destination address field of the data communication signal portion. Further, the address of the transmission source terminal 701C is stored in the network layer transmission source address column.
The MAC layer destination address stores the address of the parent terminal 701A, and the MAC layer transmission source address stores the address of the transmission source terminal 701C.
There may be a peripheral terminal 701B that does not have a hierarchical relationship with the transmission source terminal 701C within the reach of the wireless signal, and a packet transmitted by the transmission source terminal 701C may be received, but the beacon destination address is addressed to itself. Therefore, the packet received by the peripheral terminal 701B is discarded.
(4)
The parent terminal 701A receives the control signal and transfers the data communication signal to the destination terminal 701D.
The address of the destination terminal 701D, which is the final receiving terminal, is stored in the network layer destination address field of the data communication signal portion. Further, the address of the transmission source terminal 701C is stored in the network layer transmission source address column.
Further, the address of the destination terminal 701D is stored in the MAC layer destination address, and the address of the parent terminal 701A is stored in the MAC layer transmission source address.

By configuring in this way, the data communication signal can be transmitted together with the control signal. Therefore, in the network configuration having the parent-child relationship as shown in FIG. Can be reduced.
When the parent terminal 701A transfers the data communication signal portion, it can be configured to wait without transferring until the control signal transmission timing, as in FIG. 5 of the first embodiment. is there.

FIG. 10 is another configuration example of the format of the communication packet of the wireless communication terminal 701 in the third embodiment.
In the packet format shown in FIG. 8, since the destination address of the control signal and the data communication signal is different and involves packet transfer, both the MAC layer address and the network layer address are required for the data communication signal portion. did.
However, when the destinations of the control signal and the data communication signal are the same, the MAC layer address can be omitted, and the format shown in FIG. 10 can be used.
The actual packet transfer will be described with reference to FIG.

FIG. 11 shows another example of how packets are transferred in the third embodiment.
In FIG. 11, the transmission source terminal 701C intends to transmit both a control signal and a data communication signal to the parent terminal 701A. In this case, since the destinations of the control signal and the data communication signal match, the packet format shown in FIG. 10 is used.
There may be a peripheral terminal 701B that does not have a hierarchical relationship with the transmission source terminal 701C within the reach of the wireless signal, and the packet transmitted by the transmission source terminal 701C may be received. Since the address is not addressed to itself, the packet received by the peripheral terminal 701B is discarded.

Note that the transmission data generation unit 205 of the wireless communication terminal may have a function of switching between using the transmission packet format of FIG. 3 or using the formats of FIG. 8 and FIG.
With this configuration, the format of the transmission packet can be freely switched according to the network configuration and the positional relationship of each terminal on the network, reducing the overall signal amount in more diverse situations. It becomes possible to do.

  As described above, according to the third embodiment, it is possible to reduce the overall signal amount even in a wireless network configuration having a hierarchical relationship, as in the first embodiment.

Embodiment 4 FIG.
In the second embodiment, the configuration has been described in which the control signal is transmitted together with the data communication signal in a situation where it is not necessary to send the control signal at a predetermined interval, thereby reducing the overall signal amount.
In the fourth embodiment of the present invention, a configuration in which the overall signal amount is reduced by the same method as in the second embodiment in a wireless network managed in a hierarchical relationship as described in the third embodiment will be described. .
Note that the configuration of the wireless communication terminal is the same as that of FIG.

  In the third embodiment, the control signal is periodically transmitted to the parent terminal 701A at a predetermined interval. However, as in the second embodiment, the control signal need not be transmitted at the predetermined interval. The control signal management unit 606 only needs to generate data necessary for the control signal when requested.

Next, the operation of the wireless communication terminal according to the fourth embodiment will be described.
When the data communication signal is generated in the reception data processing unit 604 or itself, the transmission data generation unit 605 requests the control signal management unit 606 for data necessary for the control signal.
The control signal management unit 606 generates and outputs data necessary for the control signal in response to a request from the transmission data generation unit 605.
The contents of the packet are the same as in the third embodiment.

In the case where an upper limit is set for the transmission interval of the control signal, the configuration is as follows, as in the second embodiment.
(1) First, storage means such as a RAM for storing the upper limit value is provided.
(2) The elapsed time after transmitting the control signal is counted by the internal clock of the wireless communication terminal and stored in the storage means.
(3) When the control signal is transmitted together with the data communication signal, the elapsed time is reset. The reset operation may be performed by the transmission data generation unit 605 or the control signal management unit 606.
(4) When the upper limit is reached without transmitting the control signal, the control signal is exceptionally transmitted alone.

  As described above, according to the fourth embodiment, even in a wireless network configuration having a hierarchical relationship, the overall signal amount can be reduced as in the second embodiment.

Embodiment 5. FIG.
In the first to fourth embodiments, the configuration in which the overall signal amount is reduced by transmitting the control signal and the data communication signal in a single packet has been described.
In Embodiment 5 of the present invention, a method for estimating the position of a mobile terminal based on signals transmitted and received by a wireless communication terminal under the configuration as in Embodiments 1 to 4 will be described.

FIG. 12 shows a configuration example of a wireless network in the fifth embodiment.
The configuration of the wireless network in FIG. 12 is basically the same as that in FIG. 1 in the first embodiment, but it is assumed that the mobile wireless terminal 1202 moves in the wireless network configured by the fixed wireless terminal 1201.
Fixed wireless terminal 1201 has the configuration described in Embodiments 1 to 4, and similarly transmits a control signal and a data communication signal in a single packet.
The configuration of the mobile radio terminal 1202 is the same as that in FIG. 2, but the receiving circuit 202 receives a signal even if it is a signal addressed to another terminal, and outputs necessary information to the received data processing unit 204.
In the wireless network configuration as shown in FIG. 12, it is necessary to estimate the current position of the mobile wireless terminal 1202 and select an appropriate communication partner.

Here, the distance from the fixed wireless terminal 1201 and the like can be estimated based on the reception intensity of the wireless signal transmitted by the fixed wireless terminal 1201, and thereby the position of the mobile wireless terminal 1202 can be estimated.
In this case, it does not matter whether the type of the radio signal is a control signal or a data communication signal. Further, since the signal content is not processed, it may be a signal addressed to another terminal.
By providing means for estimating the position of the mobile radio terminal 1202 based on the reception strength of the radio signal in the terminal as described above, the position of the mobile radio terminal 1202 can be estimated based on a packet other than that addressed to the own terminal. The reference signal transmitted / received only for detecting the position can be reduced, and the overall signal amount can be further reduced.

In particular, in the case of the configuration of Embodiment 2 or 4 in which the control signal is transmitted together with the data communication signal when the data communication signal is transmitted, if the frequency of data communication signal transmission is high, the mobile radio terminal 1202 By estimating the position, the necessity of transmitting a reference signal for position estimation is greatly reduced, which contributes to a reduction in signal amount.
In addition, even in the case of the configuration of the first and third embodiments in which the data communication signal is transmitted together with the control signal that is periodically transmitted at a predetermined interval, a signal that can be used for position estimation periodically is obtained. There is a certain effect.

  Note that the position estimation method is not limited to the reception strength of the wireless signal transmitted by the fixed wireless terminal 1201. For example, the position information of the fixed wireless terminal 1201 is grasped in advance and any fixed wireless terminal is received at the time of signal reception. Depending on whether the signal from 1201 is received, it is also possible to estimate in which range the mobile radio terminal 1202 is located.

Further, the same effect can be obtained even when the reference signal is used for purposes other than position estimation.
For example, a case where a reference signal is used for management of a network configuration or the like can be considered. In this case, since the frequency of usable signals increases, information can be updated quickly, and the quality of the network configuration is improved.

As described above, according to the fifth embodiment, since the antenna includes the means for estimating the distance between the wireless terminals or the position of the own terminal based on the wireless signal received by the antenna,
The signal amount of the reference signal can be effectively reduced.

2 shows a configuration example of a wireless network in the first embodiment. 1 shows a configuration of a wireless communication terminal 101 according to Embodiment 1. 4 is a format of a communication packet in the first embodiment. This is a state of transferring a packet transmitted by the wireless communication terminal 101. It is another example of transfer of the packet which the wireless communication terminal 101 transmitted. The structure of the wireless communication terminal 101 in Embodiment 2 is shown. 3 shows an example of a configuration of a wireless network in a third embodiment. 10 is a format of a communication packet in the third embodiment. In Embodiment 3, a mode that a packet is transferred is shown. It is another example of the format of a communication packet in Embodiment 3. In Embodiment 3, it is another example of a mode that a packet is transferred. 10 shows a configuration example of a wireless network in the fifth embodiment.

Explanation of symbols

  Reference Signs List 101 wireless communication terminal, 201 antenna, 202 reception circuit, 203 transmission circuit, 204 reception data processing unit, 205 transmission data generation unit, 206 control signal management unit, 601 antenna, 602 reception circuit, 603 transmission circuit, 604 reception data processing unit 605, transmission data generation unit, 606 control signal management unit, 701A parent terminal, 701B peripheral terminal, 701C transmission source terminal, 701D destination terminal.

Claims (16)

A communication method in a wireless network, in which data is transmitted / received by a data communication signal and a control signal is transmitted to all peripheral terminals at a predetermined interval,
When sending a control signal,
Put control signal and data communication signal in a single packet,
A communication method in a wireless network, wherein a destination address of each signal is stored in the packet and transmitted.   2. The communication method in a wireless network according to claim 1, wherein the data communication signal is transmitted only when the control signal is transmitted. A communication method in a wireless network that performs communication using a control signal and a data communication signal for transmitting and receiving data,
When a transmission request for a data communication signal occurs,
Put control signal and data communication signal in a single packet,
A communication method in a wireless network, wherein a destination address of each signal is stored in the packet and transmitted.   4. The communication method in a wireless network according to claim 3, wherein the control signal is transmitted only when the data communication signal is transmitted. A storage means for storing an elapsed time from the previous transmission of the control signal and an upper limit value of the transmission interval of the control signal;
When the upper limit has elapsed since the last transmission of the control signal,
Send a control signal alone,
When sending data communication signals,
The communication method in the wireless network according to claim 3, wherein the elapsed time stored in the storage means is reset. Refer to the elapsed time stored in the storage means,
6. The communication method in a wireless network according to claim 5, wherein a control signal is included in the packet only when the elapsed time is equal to or greater than a predetermined value. When the MAC layer destination address of the control signal and the data communication signal is the same,
The communication method in a wireless network according to any one of claims 1 to 6, wherein the packet is transmitted with a MAC layer address omitted from a destination address of a data communication signal. Control signal management means for outputting control signals at predetermined intervals;
Transmission data generating means for generating transmission data;
An antenna for transmitting the transmission data generated by the transmission data generating means by wireless communication and receiving a signal transmitted by another wireless communication terminal;
The transmission data generation means includes
Based on the data communication signal, the control signal output by the control signal management means, and the destination address of each signal,
A wireless communication terminal, wherein transmission data in which these data are stored in a single packet is generated at the predetermined interval and output to the antenna. Control signal management means for outputting a control signal;
Transmission data generating means for generating transmission data;
An antenna for transmitting the transmission data generated by the transmission data generating means by wireless communication and receiving a signal transmitted by another wireless communication terminal;
The transmission data generation means includes
When a transmission request for a data communication signal occurs,
Requesting the control signal management means to output a control signal;
Based on the data communication signal, the control signal output by the control signal management means, and the destination address of each signal,
A radio communication terminal characterized by generating transmission data in which these data are stored in a single packet and outputting the data to the antenna. Storage means for storing the elapsed time from the previous transmission of the control signal and the upper limit of the transmission interval of the control signal;
The transmission data generation means includes
When the upper limit has elapsed since the last transmission of the control signal,
Outputs transmission data including only control signals,
When outputting transmission data,
The wireless communication terminal according to claim 9, wherein the elapsed time stored in the storage unit is reset. The transmission data generation means includes
Refer to the elapsed time stored in the storage means,
The radio communication terminal according to claim 10, wherein the control signal is included in the transmission data only when the elapsed time is equal to or greater than a predetermined value. The transmission data generation means includes
When the MAC layer destination address of the control signal and the data communication signal is the same,
The wireless communication terminal according to any one of claims 8 to 11, wherein transmission data in which a MAC layer address is omitted from a destination address of a data communication signal is output. The transmission data generation means includes
When the MAC layer destination address of the control signal and the data communication signal is different,
To the destination address of the control signal,
The wireless communication terminal according to any one of claims 8 to 12, wherein an address including both a control signal and a MAC layer destination address of a data communication signal is set. Receiving data processing means for converting the signal received by the antenna into data;
The received data processing means includes
When both the control signal and the data communication signal are included in the received content, and when a plurality of data communication signals are included, the data is divided by a predetermined boundary identification code,
Outputting a control signal to the control signal management means;
The radio communication terminal according to any one of claims 8 to 13, wherein a data communication signal is output to the transmission data generation means.   The wireless communication terminal according to claim 14, further comprising means for estimating a distance between wireless terminals or a position of the terminal based on a wireless signal received by the antenna.   A wireless communication system comprising a plurality of wireless communication terminals according to any one of claims 8 to 15.

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