JP2003304261A - Radio communication system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To perform communication even between radio terminals which can not be directly communicated and to effectively use a hand according to situations. <P>SOLUTION: A first radio terminal 1a transmits a synchronization frame to other radio terminals for synchronizing a radio communication system, all the radio terminals 1a to 1d transmit reception state measurement frames, all the radio terminals except the first radio terminal transmit reception state information frames for informing the measured reception state to the first radio terminal, the first radio terminal creates a reception state management table from the measured reception state and the reception state in the reception state information frame, when a second communication terminal can not be directly communicated with a third radio terminal in the reception state management table, a fourth radio terminal which can be communicated with both of the second and third terminals, transfers frames except the reception state measurement frame and the reception state information frame between the second and third radio terminals. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wireless communication system having a plurality of wireless terminals, one of which manages a wireless medium (wireless communication path).

[0002]

2. Description of the Related Art In IEEE 802.11, which is the most popular conventional wireless LAN standard, when connecting a wireless LAN and a wired LAN, Infrastructur is used.
e mode (infrastructure mode) is used, and in this mode, a wireless management terminal that statically manages a wireless medium (called an access point in IEEE 802.11) serves as a connection point between a wireless LAN and a wired LAN. A wireless terminal (called a station in IEEE 802.11) adopts a star type topology in which only a connection with a wireless management terminal is established. Also,
When only a wireless LAN is configured, peer-to-peer communication called Ad-hoc mode is performed.

[0003]

However, in the above-mentioned conventional wireless communication system example, Infrastruct
When communicating between wireless terminals in the ure mode, the wireless terminal can only communicate with the wireless management terminal because of the star-type topology, and the source wireless terminal first transmits a frame to the wireless management terminal. However, it is necessary for the wireless management terminal to transfer the received frame to the destination wireless terminal. Therefore, even if direct communication is possible between wireless terminals, it is necessary to communicate via the wireless management terminal. It has a problem that it takes twice as much time and therefore the band cannot be used effectively. Further, when performing communication between wireless terminals in the Ad-hoc mode, the wireless terminals can directly communicate with each other, so that the band can be effectively used, but direct communication cannot be performed because they belong to the same wireless system. There is a problem that communication cannot be performed between wireless terminals.

In this wireless communication system, when the wireless terminals can communicate with each other, frames are directly transmitted and received between the wireless terminals, and when the direct communication cannot be performed, the wireless terminals can communicate with both wireless terminals. By transmitting and receiving frames by wireless communication, it is required that wireless terminals that belong to the same wireless communication system and cannot directly communicate with each other can also communicate, and that the band can be used effectively depending on the situation. .

In order to meet this requirement, the present invention directly transmits / receives frames between wireless terminals when communication is possible between wireless terminals, and enables communication with both wireless terminals when direct communication is not possible. By transmitting and receiving frames via wireless terminals, it is possible to perform communication even between wireless terminals that belong to the same wireless communication system and cannot directly communicate,
An object of the present invention is to provide a wireless communication system capable of effectively using a band depending on the situation.

[0006]

In order to achieve this object, a wireless communication system of the present invention is a wireless communication system having a plurality of wireless terminals, wherein a first wireless terminal synchronizes the wireless communication systems. In order to acquire the reception state measurement frame, it transmits a synchronization frame to other wireless terminals and has a wireless management function such as a terminal list management function for all wireless terminals in the wireless communication system. A reception state notification frame that transmits to all wireless terminals other than the terminal, and all the wireless terminals other than the first wireless terminal receive the reception state measurement frame and notify the reception state measured based on the received reception state measurement frame. To the first wireless terminal,
The first wireless terminal creates a reception status management table from the reception status measured based on the received reception status measurement frame and the reception status in the received reception status notification frame, and the reception status management table is created between the wireless terminals in the wireless communication system. Of the reception state management table, and when the second wireless terminal and the third wireless terminal cannot directly communicate with each other in the reception state management table, the second wireless terminal and the third wireless terminal The fourth wireless terminal capable of communicating with both of the wireless communication terminals is configured to transfer a frame other than the reception state measurement frame and the reception state notification frame between the second wireless terminal and the third wireless terminal.

As a result, when the wireless terminals can communicate with each other, frames are directly transmitted and received between the wireless terminals, and when the wireless terminals cannot communicate with each other, the frames are transmitted via the wireless terminals capable of communicating with both wireless terminals. By performing transmission / reception, it is possible to perform communication even between wireless terminals that belong to the same wireless communication system and cannot directly communicate, and obtain a wireless communication system that can effectively use the band depending on the situation.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION A radio communication system according to claim 1 of the present invention is a radio communication system having a plurality of radio terminals, and the first radio terminal is for synchronizing the radio communication systems. It transmits a synchronization frame to other wireless terminals and has a wireless management function such as a terminal list management function for all wireless terminals in the wireless communication system. All wireless terminals other than the first wireless terminal receive the reception status measurement frame and transmit a reception status notification frame to notify the reception status measured based on the received reception status measurement frame. And the first wireless terminal manages the reception status based on the reception status measured based on the received reception status measurement frame and the reception status in the received reception status notification frame. And managing the reception status between the wireless terminals in the wireless communication system by the reception status management table, and when the second wireless terminal and the third wireless terminal cannot directly communicate with each other in the reception status management table, , A fourth wireless terminal capable of communicating with both the second wireless terminal and the third wireless terminal is a reception state measurement frame and a reception state notification between the second wireless terminal and the third wireless terminal. The frame other than the frame is transferred.

With this configuration, when direct communication is possible between wireless terminals, frames are directly transmitted and received between the wireless terminals, and when direct communication is not possible, communication is possible with both wireless terminals. Since the frame can be transmitted / received via the terminal, transmission / reception can be performed among all the wireless terminals in the wireless communication system, and the band can be effectively used according to the situation.

A radio communication system according to a second aspect is the radio communication system according to the first aspect, wherein the first radio terminal and the fourth radio terminal are the same.

With this configuration, the first wireless terminal, which is also the fourth wireless terminal, can completely control the transfer of the frame. Therefore, except for the first wireless terminal, do nothing special regarding the transfer. It has the effect that it can be transferred without.

A radio communication system according to a third aspect is the radio communication system according to the first aspect, wherein the first radio terminal designates a fourth radio terminal.

With this configuration, if a wireless terminal having the best communication state with the second wireless terminal and the third wireless terminal is selected as the fourth wireless terminal, frame transmission / reception is performed via the wireless terminal having the best communication state. Since it can be performed, it has an effect that data can be transferred more stably.

A radio communication system according to a fourth aspect is the radio communication system according to the first aspect, wherein the first radio terminal notifies all radio terminals of the reception state management table,
The second wireless terminal or the third wireless terminal transmits a frame in which frame transfer information is set to the fourth wireless terminal based on the information obtained from the reception state management table, and the fourth wireless terminal receives the frame. The frame in which the frame transfer information is set is transferred to the third wireless terminal or the second wireless terminal.

With this configuration, the second wireless terminal or the third wireless terminal which is going to transmit the frame can specify the wireless terminal to be transferred as the fourth wireless terminal.
If the wireless terminal having the best communication state with the second wireless terminal and the third wireless terminal is selected as the fourth wireless terminal, the frame can be transmitted and received via the wireless terminal having the best communication state. This has the effect that the transfer can be performed with less additional load on the first wireless terminal, which has a heavy load for executing the wireless management function.

A wireless communication system according to a fifth aspect is the wireless communication system according to the first aspect, wherein the first wireless terminal indicates the execution suitability of the wireless management function for all the wireless terminals by the reception state management table. Create an aptitude ranking table, first
If the wireless terminal of is not in the first aptitude ranking of the aptitude ranking table,
The wireless management function and the reception state management table are automatically transferred from the first wireless terminal to a wireless terminal having a higher order of suitability.

With this configuration, since the wireless terminal most suitable for executing the wireless management function in the wireless communication system can execute the wireless management function, the most reliable wireless communication system can be constructed.

A radio communication system according to a sixth aspect is the radio communication system according to the first aspect, wherein the first radio terminal shows the execution suitability of the radio management function for all the radio terminals by a reception state management table. Create an aptitude ranking table, first
If the first wireless terminal becomes unable to execute the wireless management function by notifying all the wireless terminals of the aptitude ranking table, the wireless terminals of other than the first wireless terminal according to the ranking of the aptitude ranking table. The wireless management function is transferred to the wireless terminal.

With this configuration, when it becomes impossible for the wireless terminal that is executing the wireless management function to execute the wireless management function, the wireless terminal that is most suitable for executing the wireless management function in the wireless communication system is wirelessly managed. Since the function can be executed, a more stable wireless communication system can be reconstructed.

The radio communication system according to claim 7 is the radio communication system according to any one of claims 1 to 6, wherein all the radio terminals other than the first radio terminal are all radio terminals other than the self terminal. The reception state measured by receiving the reception state measurement frame from is notified to the first wireless terminal as one reception state notification frame.

With this configuration, a plurality of reception status notifications can be completed once, which has been conventionally performed with (total number of wireless terminals-1) times, so that it is used for reception status notifications. This has the effect that the time is shortened and the band can be used effectively.

FIG. 1 shows an embodiment of the present invention.
Will be explained.

(Embodiment 1) FIG. 1 is a block diagram showing a radio communication system according to Embodiment 1 of the present invention.

In FIG. 1, reference numerals 1a, 1b, 1c, and 1d denote wireless terminals capable of transmitting and receiving, 2a, 2b, 2c, 2d, and 2a.
e and 2f are actually invisible wireless communication paths, and 2a
Is a wireless communication path between the wireless terminals 1a and 1b, 2b
Is a wireless communication path between the wireless terminals 1a and 1c, 2c is a wireless communication path between the wireless terminals 1a and 1d, 2d is a wireless communication path between the wireless terminals 1b and 1d, and 2e is a wireless terminal 1c. A wireless communication path between the wireless terminals 1d and 2f is a wireless communication path between the wireless terminals 1b and 1c. here,
The wireless communication path 2f marked with x indicates that communication is not possible, and the other wireless communication paths 2a, 2a not marked with x are shown.
b, 2c, 2d, and 2e indicate that normal communication is possible.
(Table 1) is a reception state management table in the wireless communication system according to the present embodiment.

[0025]

[Table 1]

In Table 1, the leftmost column shows transmitting wireless terminals 1a, 1b, 1c, 1d which transmit frames, and the second column shows the case where the wireless terminal 1a receives a frame from each transmitting wireless terminal. The receiving state is shown, the third column shows the receiving state when the wireless terminal 1b receives a frame from each transmitting wireless terminal, and the fourth column the wireless terminal 1c receives a frame from each transmitting wireless terminal. In this case, the rightmost column shows the receiving state when the wireless terminal 1d receives a frame from each transmitting wireless terminal. In (Table 1), the reception strength is set to the reception state for values that can be received without error. The maximum received intensity is 100, and the received intensity is logarithmically determined. If the reception strength is small enough, the frame cannot be received normally, and if it is not large enough, it cannot be received without error. In Table 1, it is assumed that the reception strength is 50 or more and normal reception is possible. If the reception strength is in the range of 0 to 49, normal reception cannot be performed, so the reception state is set to 0. Therefore,
The reception states in (Table 1) are 0 and values of 50 or more.

The operation of the wireless communication system configured as above will be described.

If the wireless terminal 1a is executing the wireless management function, the wireless terminal 1a notifies the other wireless terminals of the transmission instruction of the reception state measurement frame within the synchronization frame of the broadcast frame, and then the wireless terminal 1a. The wireless terminals other than 1a transmit the reception state measurement frame. The wireless terminal 1a needs to update the reception state management table (Table 1) in order to cope with an increase / decrease in the number of wireless terminals that can communicate due to ON / OFF of the power of the wireless terminal or a change in the radio wave state due to disturbance. However, if the transmission instruction of the reception state measurement frame is issued every time the wireless terminal 1a transmits the synchronization frame, the update frequency becomes high. Therefore, the wireless terminal 1a issues a reception state measurement frame transmission instruction to a specific synchronization frame, and if there is no reception state measurement frame transmission instruction in the synchronization frame, no wireless terminal transmits the reception state measurement frame. If there is an instruction to send a reception status measurement frame,
The wireless terminal 1a updates the reception state management table (Table 1) by the wireless terminal transmitting the reception state measurement frame.

Here, a case where the wireless terminal 1b transmits a reception state measurement frame will be described. The wireless terminal 1b transmits one broadcast reception state measurement frame. The wireless terminals 1c and 1d use the reception state notification frame to notify the wireless terminal 1a of the reception state when the reception state measurement frame is received. However, in reality, the wireless terminal 1
Since c cannot receive the reception state measurement frame, the wireless terminal 1a receives only the reception state notification frame from the wireless terminal 1d. Wireless terminal 1a
Is the reception state 65 measured by the reception state measurement frame of the wireless terminal 1b, and the reception state 8 notified by the reception state notification frame from the wireless terminal 1d.
0, 0 is stored in the corresponding location of the wireless state management table as the receiving state of the wireless terminal 1c which is present in the terminal list but is not notified of the receiving state notification frame. The wireless terminals 1c and 1d similarly transmit the reception state measurement frame, and the wireless terminal 1a stores the respective reception states in the corresponding locations of the wireless state management table. Wireless terminal 1a
When transmitting a reception state measurement frame, the wireless terminal 1
The wireless status management table (Table 1) receives the received status notification frames from all of b, 1c, and 1d, and reports the received status.
In the corresponding locations. In this way, the wireless status management table is updated.

Next, a case where a frame is transmitted from a wireless terminal other than the wireless terminal 1a to another wireless terminal will be described. Here, in order to distinguish the frame transferred by the wireless terminal 1a from the original frame, it will be referred to as a transfer frame. In the case of FIG. 1, since the wireless terminal 1a executes the wireless management function, all the received frames including the addressed to other wireless terminals are temporarily stored and stored until it is determined that the frames can be discarded. . First, considering the case where a frame is transmitted from the wireless terminal 1b to the wireless terminal 1c that needs to be transferred, the wireless terminal 1a stores the frame received from the wireless terminal 1b. According to the reception state management table (Table 1), the frame from the wireless terminal 1b is received by the wireless terminal 1a.
Since it can be seen that it cannot be received in c, the storage frame is transmitted as a transfer frame, and when the wireless terminal 1c normally receives the storage frame, the storage frame is discarded. Since the frame of the broadcast from the wireless terminal 1b is considered as a kind of frame to the wireless terminal 1c, the wireless terminal 1a similarly transfers the frame. Further, considering the case where a frame is transmitted from the wireless terminal 1b to the wireless terminal 1d, which does not need to be transferred, the wireless terminal 1a stores the received frame. Since the wireless terminal 1a knows from the reception state management table (Table 1) that the frame from the wireless terminal 1b can be received by the wireless terminal 1d, it immediately discards the stored frame.

In this embodiment, the case where there are four wireless terminals has been described, but it goes without saying that the number of wireless terminals may be any number. In addition, the wireless terminal performing the wireless management function notifies the transmission instruction of the reception state measurement frame in the synchronization frame. However, no matter what frame is notified, or even if there is no transmission instruction, the wireless communication system Needless to say, the same applies if each wireless terminal transmits a reception state measurement frame at a certain timing and the reception state measured by the wireless terminal that has received the reception state measurement frame is transmitted as a reception state notification frame. The value of the reception state has been described based on the reception strength, but the value is not limited to the reception strength. Also, the reception status measurement frame has been described as a dedicated frame used only for measuring the reception status, but other frames having other purposes may be substituted, and the reception status notification frame is used only for notification of the reception status. However, the reception status information may be added to another frame having another purpose and used.

As described above, in the present embodiment, when communication is possible between wireless terminals, frames are directly transmitted and received between the wireless terminals, and when direct communication is not possible, communication is possible with both wireless terminals. Since the frame can be transmitted and received via the wireless terminal, transmission and reception can be performed among all the wireless terminals in the wireless communication system, and the band can be effectively used depending on the situation. In particular, when a wireless terminal performing the wireless management function transfers a frame, the wireless terminal performing the wireless management function can completely control the frame transfer. Can also be transferred without doing anything special.

(Second Embodiment) The configuration of a radio communication system according to the second embodiment of the present invention is the same as that of the first embodiment, as shown in FIG.

The operation of the wireless communication system thus configured will be described with reference to the reception state management table (Table 1).

The wireless terminal 1a executes the wireless management function to update the reception status management table (Table 1). After this update,
It can be seen that the wireless terminal 1a cannot communicate with the wireless terminals 1b and 1c and needs to transfer frames. The wireless terminal 1a determines from the reception state management table (Table 1) that it and the wireless terminal 1d can communicate with both the wireless terminals 1b and 1c, and which is suitable for transfer. When a frame is transferred from the wireless terminal 1b to the wireless terminal 1c, the reception status of the wireless terminal 1a from the wireless terminal 1b is 65, the reception status of the wireless terminal 1c from the wireless terminal 1a is 60, and the total reception status is Is 125. The reception status of the wireless terminal 1d from the wireless terminal 1b is 80.
The reception status of the wireless terminal 1c from the wireless terminal 1d is 75, and the total reception status is 155. Therefore, since the total reception state of the wireless terminal 1d is larger,
The wireless terminal 1d is suitable for transferring a frame from the wireless terminal 1b to the wireless terminal 1c.

Similarly, when a frame is transferred from the wireless terminal 1c to the wireless terminal 1b, the wireless terminal 1c of the wireless terminal 1a
Is 60, the reception state of the wireless terminal 1b from the wireless terminal 1a is 65, and the total reception state is 1
25. The receiving state of the wireless terminal 1d from the wireless terminal 1c is 75, the receiving state of the wireless terminal 1b from the wireless terminal 1d is 80, and the total receiving state is 155.
Therefore, since the wireless terminal 1d has a larger total reception state, the wireless terminal 1d is suitable for transferring a frame from the wireless terminal 1c to the wireless terminal 1b. Therefore, the wireless terminal 1a transmits, to the wireless terminal 1d, a frame designating transfer of a frame from the wireless terminal 1b to the wireless terminal 1c, and also designates transfer of a frame from the wireless terminal 1c to the wireless terminal 1b. Send the frame.

When transmitting a frame from the wireless terminal 1b to the wireless terminal 1c, the wireless terminal 1d temporarily stores the frame transmitted from the wireless terminal 1b, transmits the stored frame as a transfer frame, and normally receives the frame to the wireless terminal 1c. If so, the storage frame is discarded. Since the frame of the broadcast from the wireless terminal 1b is considered as a kind of frame to the wireless terminal 1c, the wireless terminal 1d similarly transfers the frame.

In this embodiment, the total of the reception state values is used to determine the transfer wireless terminal. However, comparing the reception state from the transmission wireless terminal and the reception state of the reception wireless terminal, It goes without saying that a larger value may be used as the transfer wireless terminal.

As described above, when communication is performed between wireless terminals that cannot be directly communicated with each other in the present embodiment, frame transmission and reception can be performed via the wireless terminal having the best communication state with the two wireless terminals. Data can be transferred more stably.

(Third Embodiment) The configuration of a wireless communication system according to the third embodiment of the present invention is the same as that of the first embodiment, as shown in FIG.

The radio communication system thus configured will be described with reference to the reception state management table (Table 1).

In the present embodiment, the wireless terminal 1a executes the wireless management function to periodically update the reception status management table (Table 1) and update the reception status management table (Table 1). ,
The reception state management table (Table 1) is notified to all wireless terminals in the synchronization frame of the broadcast frame.

When the wireless terminal 1b transmits a frame to the wireless terminal 1c, it can be seen from the reception state management table (Table 1) that direct communication is impossible and frame transfer is necessary. From the reception state management table (Table 1), the wireless terminal 1b determines that the wireless terminal that can communicate with both the wireless terminals 1b and 1c is the wireless terminal 1
It is a and 1d, and it is judged which is suitable for transfer. When a frame is transferred from the wireless terminal 1b to the wireless terminal 1c, the reception status of the wireless terminal 1a from the wireless terminal 1b is 65, the reception status of the wireless terminal 1c from the wireless terminal 1a is 60, and the total reception status is Is 125. The reception state of the wireless terminal 1d from the wireless terminal 1b is 80,
The reception status of the wireless terminal 1c from the wireless terminal 1d is 75, and the total reception status is 155. Therefore, since the wireless terminal 1d has a larger total reception state, the wireless terminal 1b determines that the wireless terminal 1d is suitable for transferring the frame from the wireless terminal 1b to the wireless terminal 1c. Therefore, the wireless terminal 1b transmits a frame from the wireless terminal 1b to the wireless terminal 1c by designating transfer to the wireless terminal 1d.

When a frame is transmitted from the wireless terminal 1b to the wireless terminal 1c, frame transfer is designated for the wireless terminal 1d. Therefore, the wireless terminal 1d temporarily stores the frame transmitted from the wireless terminal 1b, The storage frame is transmitted as a transfer frame, and when it is normally received by the wireless terminal 1c, the storage frame is discarded. Since the frame of the broadcast from the wireless terminal 1b is considered as a kind of frame to the wireless terminal 1c, the wireless terminal 1b similarly designates the transfer of the frame and transmits it.

In this embodiment, the reception state management table (Table 1) is notified in the synchronization frame, but it goes without saying that any frame may be used for notification.

As described above, in this embodiment, when communication is performed between wireless terminals that cannot directly communicate with each other, the wireless terminal that transmits the frame can specify the wireless terminal to which the frame is transferred. The transfer can be performed with less additional load on the wireless terminal (here, the wireless terminal 1a) that has a heavy load for execution.

(Embodiment 4) The configuration of the radio communication system according to Embodiment 4 of the present invention is the same as that of Embodiment 1 and is shown in FIG.

With respect to the wireless communication system configured as described above, a reception status management table (Table 1) and an aptitude table showing a degree suitable for execution of the wireless management function (Table 2).
It will be explained using and.

[0049]

[Table 2]

The wireless terminal 1a executes the wireless management function to update the reception status management table (Table 1). A method for creating an aptitude table showing the degree to which the wireless management function is suitable will be described using this reception state management table (Table 1).

When a frame is transmitted from the wireless terminal 1a, the receiving status of the wireless terminal 1b is 65, the receiving status of the wireless terminal 1c is 60, the receiving status of the wireless terminal 1c is 90, and the total receiving status is 215. is there. When the wireless terminal 1a receives the frame, the reception state from the wireless terminal 1b is 6
5, the reception state from the wireless terminal 1c is 60, the wireless terminal 1c
Is 90 and the total receiving status is 215. Therefore, the total of all reception states regarding the wireless terminal 1a is 430. When calculated in the same manner, the wireless terminal 1b has a value of 290, the wireless terminal 1c has a value of 270, and the wireless terminal 1d has a value of 490. The suitability ranking table (Table 2) is shown in descending order of the total of these reception states.

The wireless terminal 1a executing the wireless management function
Knows from the suitability table (Table 2) that the self is not in the first suitability rank and that the wireless terminal 1d is more suitable to execute the wireless management function. The wireless terminal 1a is the wireless terminal 1d
The wireless management function transfer frame for transferring the execution of the wireless management function is transmitted, and after confirming that the wireless terminal 1d normally receives and executes the wireless management function, the wireless management function is executed. Stop.

In the present embodiment, when the suitability ranking table (Table 2) is created, the judgment is made by simply adding all the related reception states. Even if the determination is made by another method such as the order in which the sensitivity is larger than the reference value and the variation is small, the same effect can be obtained. Also,
The case where the wireless management function transfer frame is used to dynamically move the reception state management table (Table 1) has been described, but the present invention is not limited to this method.

As described above, in the present embodiment, since the wireless terminal most suitable for executing the wireless management function in the wireless communication system can execute the wireless management function, the most reliable communication can be performed. A wireless communication system can be constructed.

(Embodiment 5) The configuration of the radio communication system according to Embodiment 5 of the present invention is the same as that of Embodiment 1 and is shown in FIG.

With respect to the wireless communication system configured as described above, there are a reception state management table (Table 1) and an aptitude order table showing a degree suitable for execution of the wireless management function (Table 2).
It will be explained using and.

The wireless terminal 1a executes the wireless management function to update the reception status management table (Table 1). Using this reception status management table (Table 1), an aptitude order table (Table 2) showing the degree to which the wireless management function is suitable is created. Embodiment 4
As described above, from the reception state management table (Table 1), the total of all reception states regarding the wireless terminal 1a is 430, 290 regarding the wireless terminal 1b, and 270 regarding the wireless terminal 1c.
Then, it is 490 for the wireless terminal 1d. An aptitude ranking table (Table 2) shown in descending order of the total of these reception states is created. The wireless terminal 1a notifies all wireless terminals of the suitability ranking table (Table 2) in the synchronization frame of the broadcast frame.

If the wireless terminal 1a cannot execute the wireless management function for some reason, all wireless terminals in the wireless communication system cannot receive the synchronization frame for a specified period.
The wireless terminal 1d having the highest aptitude rank other than the wireless terminal 1a in the aptitude order table (Table 2) immediately executes the wireless management function. At this time, if the wireless management function of the wireless terminal 1d cannot be executed and there is no synchronization frame for a specified time (that is, the defined time x 2 after the first synchronization frame is lost), the wireless terminal 1b of the next appropriate rank is further added. Perform wireless management functions. In this way, the wireless management function is executed by waiting for the synchronization frame for a specified time in order from the wireless terminal having the highest suitability.

In this embodiment, the reception state management table (Table 1) is notified in the synchronization frame, but it goes without saying that any frame may be notified. Also, the wireless management function is executed by waiting for a synchronization frame for a prescribed time in order from the wireless terminal having the highest aptitude order, and as a result, the wireless management function is executed in order from the top of the aptitude order table (Table 2). By doing so, the same effect can be obtained.

As described above, this embodiment is most suitable for executing the most wireless management function in the wireless communication system when the wireless terminal executing the wireless management function cannot execute the wireless management function. Since the wireless management function can be executed in order of the wireless terminals, it is possible to reconstruct the wireless communication system capable of performing the most reliable communication.

(Embodiment 6) The configuration of a radio communication system according to Embodiment 6 of the present invention is the same as that of Embodiment 1 and is shown in FIG.

The operation of the radio communication system configured as described above will be described.

If the wireless terminal 1a is executing the wireless management function, the wireless terminal 1a notifies the other wireless terminals of the transmission instruction of the reception state measurement frame in the synchronization frame of the broadcast frame, and then the wireless terminal 1a. The wireless terminals other than 1a transmit the reception state measurement frame. here,
Consider a case where the wireless terminal 1b receives the reception state measurement frame. The wireless terminal 1b includes wireless terminals 1a, 1c and 1
A reception state measurement frame is transmitted from each of d, and a reception state 65 is obtained from the received reception state measurement frame of the wireless terminal 1a, and a reception state 80 is obtained from the received reception state measurement frame of the wireless terminal 1d. Since the wireless terminal 1b cannot communicate with the wireless terminal 1c, even if a certain period of time elapses from the notification of the transmission instruction of the reception state measurement frame, the wireless terminal 1b
Since the reception state measurement frame from c cannot be received, the reception state from the wireless terminal 1c is determined to be 0. The wireless terminal 1b uses one reception state notification frame that is a combination of these three pieces of wireless terminal information and reception state information, and the wireless terminal 1b
Send to a. The wireless terminal 1c has a reception state 60 with the wireless terminal 1a, a reception state 0 with the wireless terminal 1b, and a wireless terminal 1d.
It is transmitted to the wireless terminal 1a in one reception state notification frame in which the reception states 75 and are combined. The wireless terminal 1d has a reception state 90 with the wireless terminal 1a and a reception state 8 with the wireless terminal 1b.
0, the reception state 75 with the wireless terminal 1d is set as one set, and the reception state notification frame is transmitted to the wireless terminal 1a. In this way, when the reception state notification frame is transmitted for each reception state measurement frame including the expected frame that could not be received, the transmission of the reception state notification frame 9 times only needs to be transmitted 3 times.

As described above, in the present embodiment, the number of times of transmission of a plurality of reception status notification frames, which was conventionally required to be (total number of wireless terminals-1) times, is now required to be 1. The time used for the status notification frame is shortened, and the band can be effectively used.

[0065]

As described above, according to the wireless communication system of the first aspect of the present invention, the wireless communication system has a plurality of wireless terminals, and the first wireless terminal is a wireless communication system. It transmits a synchronization frame to other wireless terminals for synchronization, and has a wireless management function such as a terminal list management function of all wireless terminals in the wireless communication system. To all wireless terminals other than the own terminal, and all wireless terminals other than the first wireless terminal receive the reception state measurement frame and notify the reception state measured based on the received reception state measurement frame. The notification frame is transmitted to the first wireless terminal, and the first wireless terminal receives the reception state measured based on the received reception state measurement frame and the reception state in the received reception state notification frame. From the wireless communication system, the reception status between the wireless terminals in the wireless communication system is managed by the reception status management table, and the second wireless terminal and the third wireless terminal directly communicate with each other in the reception status management table. Second, if not possible
The fourth wireless terminal capable of communicating with both of the wireless terminal and the third wireless terminal of the second wireless terminal other than the reception state measurement frame and the reception state notification frame between the second wireless terminal and the third wireless terminal. By transferring a frame, when direct communication is possible between wireless terminals, frames are directly sent and received between wireless terminals, and when direct communication is not possible, wireless communication is possible with both wireless terminals. Since the frame can be transmitted / received via the terminal, it is possible to transmit / receive between all the wireless terminals in the wireless communication system, and it is possible to effectively use the band depending on the situation. To be

According to the wireless communication system of the second aspect, in the wireless communication system of the first aspect, the first
Since the wireless terminal of and the fourth wireless terminal are the same,
Since the first wireless terminal, which is also the fourth wireless terminal, can completely control the transfer of the frame, it can be transferred without doing anything special regarding the transfer except for the first wireless terminal. An advantageous effect is acquired.

According to the wireless communication system of claim 3, in the wireless communication system of claim 1,
By specifying the fourth wireless terminal, the wireless terminal having the best communication status with the second wireless terminal and the third wireless terminal can be selected as the fourth wireless terminal. Since the frame can be transmitted and received via the terminal, the advantageous effect that the data can be transferred more stably is obtained.

According to the wireless communication system of the fourth aspect, in the wireless communication system of the first aspect, the first
Wireless terminal notifies the reception state management table to all wireless terminals, and the second wireless terminal or the third wireless terminal uses the information obtained from the reception state management table to send a frame to the fourth wireless terminal. The frame in which the transfer information is set is transmitted, and the fourth wireless terminal attempts to transmit the frame by transferring the received frame in which the frame transfer information is set to the third wireless terminal or the second wireless terminal. Since the second wireless terminal or the third wireless terminal can designate the wireless terminal to transfer as the fourth wireless terminal, the second wireless terminal or the third wireless terminal most communicates with the second wireless terminal and the third wireless terminal. If you select a wireless terminal with a good communication status, you can send and receive frames via the wireless terminal with the best communication status. Advantageous effect can be transferred with less burden is obtained.

According to the wireless communication system of the fifth aspect, in the wireless communication system of the first aspect, the first
The wireless terminal of creates a suitability table showing the suitability of execution of the wireless management function for all wireless terminals by the reception state management table, and when the first wireless terminal is not in the first suitability list of the suitability table, the wireless terminal By automatically moving the management function and the reception state management table from the first wireless terminal to the wireless terminal with the highest suitability, the wireless terminal in the wireless communication system that is most suitable for executing the wireless management function executes the wireless management function. Therefore, there is an advantageous effect that the most reliable wireless communication system can be constructed.

According to the wireless communication system of claim 6, in the wireless communication system of claim 1,
The wireless terminal of No. 1 creates an aptitude ranking table showing the execution aptitude of the wireless management function for all the wireless terminals from the reception state management table, and the first wireless terminal notifies all the wireless terminals of the aptitude ranking table, When it becomes impossible for the wireless terminal to execute the wireless management function, the first order is performed according to the order of the aptitude table.
If the wireless management function cannot be executed in a wireless terminal that is executing the wireless management function by moving the wireless management function to a wireless terminal other than the wireless terminal of Since the wireless terminal suitable for execution can execute the wireless management function, there is an advantageous effect that a more stable wireless communication system can be reconstructed.

According to the wireless communication system of claim 7, in the wireless communication system of any one of claims 1 to 6, all wireless terminals other than the first wireless terminal are all wireless terminals other than the own terminal. Conventionally, a plurality of reception states are notified by notifying the first wireless terminal of the reception state measured by receiving the reception state measurement frame from the wireless terminal as one reception state notification frame (total number of wireless terminals-1 Since it is possible to do what has been done in one time only once, the time used for notification of the reception state is shortened, and the advantageous effect that the band can be used effectively can be obtained.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a wireless communication system according to first, second, third, fourth, fifth and sixth embodiments of the present invention.

[Explanation of symbols]

1a to 1d wireless terminals 2a to 2f wireless communication path

Claims (7)

[Claims] 1. A wireless communication system having a plurality of wireless terminals, wherein a first wireless terminal transmits a synchronization frame to another wireless terminal to synchronize the wireless communication system, and Having a wireless management function such as a terminal list management function of all wireless terminals in a wireless communication system, the all wireless terminals transmit a reception state measurement frame to all the wireless terminals other than the own terminal, and the first wireless All the wireless terminals other than the terminal receives the reception state measurement frame, transmits a reception state notification frame for notifying the reception state measured based on the received reception state measurement frame to the first wireless terminal, The first wireless terminal receives a reception state management table based on the reception state measured based on the received reception state measurement frame and the reception state in the received reception state notification frame. And managing the reception status between the wireless terminals in the wireless communication system with the reception status management table, and the second wireless terminal and the third wireless terminal cannot directly communicate with each other in the reception status management table. In this case, the fourth wireless terminal capable of communicating with both the second wireless terminal and the third wireless terminal is the fourth wireless terminal between the second wireless terminal and the third wireless terminal. A wireless communication system, which transfers a frame other than the reception state measurement frame and the reception state notification frame. 2. The wireless communication system according to claim 1, wherein the first wireless terminal and the fourth wireless terminal are the same. 3. The wireless communication system according to claim 1, wherein the first wireless terminal designates the fourth wireless terminal. 4. The first wireless terminal notifies the reception status management table to all the wireless terminals, and the second wireless terminal or the third wireless terminal obtains from the reception status management table. Based on the received information, a frame in which frame transfer information is set is transmitted to the fourth wireless terminal, and the fourth wireless terminal transmits the received frame in which the frame transfer information is set to the third wireless terminal or the The wireless communication system according to claim 1, wherein the wireless communication system transfers to a second wireless terminal. 5. The first wireless terminal creates an aptitude order table showing the execution aptitude of the wireless management function for all the wireless terminals based on the reception status management table, and the first wireless terminal sets the aptitude order. 2. The wireless management function and the reception state management table are automatically moved from the first wireless terminal to a wireless terminal having a higher suitability rank when the rank is not in the first suitability rank in the table. Wireless communication system. 6. The first wireless terminal creates an aptitude order table showing execution aptitude of the wireless management function for all of the wireless terminals based on the reception status management table, and the first wireless terminal sets the aptitude order. When all the wireless terminals are notified of the table and it becomes impossible for the first wireless terminal to execute the wireless management function, other than the first wireless terminal according to the order of the aptitude table. The wireless communication system according to claim 1, wherein the wireless management function is transferred to a wireless terminal. 7. All wireless terminals other than the first wireless terminal are:
7. The reception state measured by receiving the reception state measurement frame from all the wireless terminals other than the own terminal is notified to the first wireless terminal as one reception state notification frame. The wireless communication system according to item 1.