JP2728044B2 - Mobility management device in SS wireless communication - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a spread spectrum (SS) radio communication terminal (ST: Stati).
on), an access point (A) which is a wireless bridge connecting an SS wireless communication network and a wired communication network.
The present invention relates to a mobility management device in SS wireless communication that includes a P: Access Point), a server, and a wired communication medium that connects the plurality of access points AP and the server, and manages mobility.

[0002]

2. Description of the Related Art Conventionally, in the SS radio communication of the direct spread system, the bandwidth is narrow, so that the number of usable channels is small, and an SS communication network comprising a radio communication terminal ST, a plurality of access points AP, a server and a wired communication medium. , The same channel is often used even when a basic service area BSA (Basic Service Area), which is a range communicable with the access point AP, is adjacent.

[0003] There are the following two modes in which the wireless communication terminal ST accesses the server in the SS communication network. The first is usually one basic service area BS
The wireless communication terminal ST is connected to an access point AP in the basic service area BSA and accesses the server through the access point AP. The second is a case where the wireless communication terminal ST moves to another basic service area BSA, and while the wireless communication terminal ST is moving, the wireless communication terminal ST monitors the received electric field strength of the frame of the access point AP, The access point AP to be combined is switched.

FIG. 6 is a diagram showing a configuration example of a conventional SS communication network. The SS communication network shown in FIG. 6 includes a wireless communication terminal ST, wireless bridges AP1, AP2, AP3 as access points, and a wireless communication terminal ST.
Server and the wireless bridge AP1
~ AP3 and a wired communication medium for connecting the server.

Here, the range in which the wireless bridges AP1 to AP3 can communicate is defined as the basic service area BSA1,
BSA2 and BSA3 are defined, and ranges in which the reception electric field strengths of the wireless bridges AP1 to AP3 are strong and stable communication are possible in the basic service areas BSA1 to BSA3 are cell search stop areas SCS (Stop Cell Sea).
rch) 1, defined as SCS2 and SCS3. The reception electric field strength in this range is defined as an SCS level. In addition, out of the range of the basic service areas BSA1 to BSA3, and
A normal calling area RCS (Regular Cell Search) is a range in which the reception electric field strength from the wireless bridges AP1 to AP3 is weak and the other wireless bridges AP1 to AP3 need to be searched.
1, RCS2, RCS3, and the reception field strength in this range is defined as RCS level.

[0006] Outside the basic service areas BSA1 to BSA3, the reception electric field strength from the radio bridges AP1 to AP3 is weak, and the range in which communication with the radio bridges AP1 to AP3 is not possible is defined as an impossible call area FCS (Fast).
Cell Search) 1, FCS2, and FCS3, and the reception field strength in this range is defined as the FCS level. Also, the range including the basic service areas BSA1 to BSA3 is extended to an extended service area ESA (Extended Service Se
arch Area).

FIG. 7 is a diagram showing a format of a frame used in a frame exchange procedure. 6 and 7, first, a case where the first wireless communication terminal ST is normally located in one of the basic service areas BSA1 to BSA3 will be described. Basic service area BSA1 in FIG.
Is located in the extended service area E
Authentication processing is performed with the server in order to obtain permission to access the server through all wireless bridges AP1 to AP3 in the SA. The wireless communication terminal ST transmits an authentication request frame 71 in FIG. 7 to the wireless bridge AP1.

An acknowledgment (ACK) 72 to the authentication request frame in FIG. 7 is transmitted to the wireless communication terminal ST to the wireless bridge AP1 that has received the authentication request frame 71,
The ACK 72 to the authentication request frame is transferred to the server. The server that has received the ACK 72 to the authentication request frame transmits the authentication response frame 73 in FIG. 7 to the wireless bridge AP1 when permitting the access of the wireless communication terminal ST, and does nothing when not permitting. Upon receiving the authentication response frame 73, the wireless bridge AP1 communicates with the wireless communication terminal ST.
, The authentication response frame 73 is transferred. The wireless communication terminal ST transmits an ACK 74 to the authentication response frame to the wireless bridge AP1.

Next, the radio communication terminal ST performs a coupling process between the radio bridge AP1 and the radio bridge AP1 before the SS radio communication of valid data in the basic service area BSA1. First, the wireless communication terminal ST is a wireless bridge AP.
1, the connection request frame 75 in FIG. 7 is transmitted.
The wireless bridge AP1 transmits an ACK 76 to the connection request frame in FIG. 7 to the wireless communication terminal ST,
When the connection is permitted, the connection response frame 77 in FIG. 7 is transmitted to the wireless communication terminal ST. When the connection is not permitted, nothing is performed. The wireless communication terminal S that has received the combined response frame 77
T transmits an ACK 78 to the combined response frame in FIG. 7 to the wireless bridge AP1.

Next, the radio communication terminal ST communicates valid data SS with the server in the basic service area BSA1.
In order to perform wireless communication, an RS
The T-CTS-DATA-ACK frame exchange procedure is executed. First, the wireless communication terminal ST connects to the wireless bridge A
The RST frame 79 in FIG. 7 is transmitted to P1.
Upon receiving the RST frame 79, the wireless bridge AP1
The CTS frame 71 in FIG.
Send 0.

[0011] The wireless communication terminal ST that has received the CTS frame 710 sends the DATA of FIG.
After transmitting the frame 711, the wireless bridge AP1 transfers the DATA frame 711 to the server, and transmits the AC to the DATA frame in FIG.
K712 is transmitted. If there are a plurality of DATA frames 711, the previous DATA-ACK frame exchange procedure processing is repeated.

Next, the operation when the second wireless communication terminal ST moves to another basic service area BSA1 to BSA3 will be described. FIG. 6 shows a case where the wireless communication terminal ST existing in the basic service area BSA1 first moves to the basic service area BSA2. There are two patterns for movement between the wireless communication terminal ST and the basic service areas BSA1 to BSA3. The first is before sending valid data, that is, the above RST-CTS-DAT
This is a case where the wireless communication terminal ST moves before execution of the A-ACK frame exchange procedure processing. The second is transmitting valid data, that is, the above RST-CTS-DATA-
ACK or RST-CTS-DATA-ACK-D
This is a case where the wireless communication terminal ST moves during the ATA-ACK ... frame exchange procedure processing.

First, the first case will be described. After moving to the basic service area BSA2, the radio communication terminal ST exchanges the above RST-CTS- with the radio bridge AP1.
The frame exchange procedure processing of DATA-ACK is started, but the wireless bridge AP1 cannot respond because it is already outside the impossible call area FCS1. Therefore, the wireless communication terminal ST needs to be connected again to another wireless bridge AP1 to AP3, and the wireless bridge AP1 to AP3 to be connected is required.
It searches for AP3 and is coupled to the wireless bridge AP2 whose reception field strength exceeds the SCS level because it is inside the cell search stop area SCS2. Thereafter, the wireless communication terminal ST establishes the RST-CTS-DA with the wireless bridge AP2.
The TA-ACK frame exchange procedure process is restarted, and SS wireless communication of valid data is performed.

Next, the second case will be described. The wireless communication terminal ST communicates with the wireless bridge AP1 with the RS
During the processing of the T-CTS-DATA-ACK frame exchange procedure, the mobile station moves from the basic service area BSA1 to the basic service area BSA2. At this time, when the wireless communication terminal ST moves to the outside of the normal call area RCS1, the wireless communication terminal ST interrupts the ongoing frame exchange procedure processing, starts searching for the wireless bridges AP1 to AP3 to be combined, and enters the inside of the cell search stop area SCS2. Due to the presence, the reception electric field strength exceeds the SCS level and the connection with the wireless bridge AP2 is resumed, and the suspended frame exchange procedure processing is restarted.

The combining process is the same as described above, and a description thereof will be omitted. Also, the wireless bridge AP1 to be coupled
As a method of searching for AP3, a connection request frame is output by broadcast, and the received electric field strength of the ACK corresponding thereto is SCS.
A method of determining whether or not the level is exceeded can be considered.

Japanese Patent Laid-Open No. 4-54 discloses this kind of prior art.
No. 095, “Mobility management method”, January 16, 1995
The contents described on page 54 of "Nikkei Communication" published by Nikkei can be mentioned. Japanese Patent Application Laid-Open No. 4-54095 discloses a single component of a mobility management function for separating and defining the functions supporting the mobility of a personal communication user having different attributes and the mobility of a terminal. A single or a combination of functions is used to enhance the functions.

[0017]

However, the above-described prior art examples of the former mobility management apparatus and the publication in the SS radio communication have the following disadvantages.

(1) The radio communication terminal ST transmits radio bridges AP1 to APA in units of the basic service areas BSA1 to BSA3.
Basic service area B to communicate with P3
When moving from SA1 to BSA3, the wireless bridge AP1
The wireless bridges AP1 to AP3 to be newly coupled are searched for based on the received electric field strength from AP3 to AP3, and the coupling processing is performed. For this reason, when the wireless communication terminal ST moves between the basic service areas BSA1 to BSA3, it takes time to start communication of valid data, and as a result, the transmission efficiency of the entire system deteriorates.

(2) While the radio communication terminal ST is moving between the basic service areas BSA1 to BSA3, it monitors the reception electric field strength from the radio bridges AP1 to AP3 which are currently connected, and when the RCS level is reduced, another radio communication terminal ST is used. Since the search for the wireless bridges AP1 to AP3 is started, the wireless bridges AP1 to AP3 may be communicating with the currently connected wireless bridges AP1 to AP3 despite the fact that the received electric field strengths from the other wireless bridges AP1 to AP3 are large. In FIG. 6, a radio communication terminal S moving from a basic service area BSA1 to BSA2
T moves outside the cell search stop area SCS1, and further moves inside the cell search stop area SCS2.

At this point, the wireless communication terminal ST continues to communicate with the wireless bridge AP1 even though the received electric field strength from the wireless bridge AP2 is large. Further, when moving to the outside of the normal paging area RCS1, it starts searching for the wireless bridges AP1 to AP3 to be combined, and when the received electric field strength exceeds the SCS level, it joins with the wireless bridge AP2. Therefore, the currently connected wireless bridges AP1 to AP1
Normal call area RCS1 to RCS3 of AP3 and cell search stop area SCS of other wireless bridges AP1 to AP3
Wireless communication terminal ST in a range where 1 to SCS3 overlap
Communicates with the currently coupled wireless bridges AP1 to AP3 having a smaller received electric field strength.

For this reason, depending on the position where the wireless communication terminal ST is present, communication is not always performed with the wireless bridges AP1 to AP3 having the highest received electric field strength, so that communication is performed in a state worse than the original error rate at that position. As a result, the transmission efficiency of the entire system deteriorates.

(3) The radio communication terminal ST constantly monitors the received electric field strength from the radio bridges AP1 to AP3 and notifies the software. The circuit receives the received electric field strength from this circuit, and when the received electric field strength falls below the RCS level, it is immediately set. Software for executing a process of searching for and joining other wireless bridges AP1 to AP3 is required. Therefore, the device configuration and software processing of the wireless communication terminal ST are complicated.

The present invention has been made to solve the above-mentioned problems in the prior art, and eliminates the need for software for executing the combining process, simplifies the configuration of the apparatus and the configuration of the software, and realizes a wireless communication terminal. Provided is a mobile management device in SS wireless communication in which communication can be performed with the best error rate at an existing position to simplify the device scale and processing scale, reduce power consumption, and improve transmission efficiency of the entire system. With the goal.

[0024]

In order to achieve the above object, an invention according to claim 1 comprises an SS wireless terminal, a wireless bridge of an access point for connecting the SS wireless communication network and a wired communication network, a server, a plurality of servers. Consisting of a wired communication medium for connecting an access point and a server, receiving frames received by a plurality of access points during a frame exchange procedure performed when valid data is communicated between the SS wireless terminal and the access point. the magnitude of the electric field strength server compares, put the SS wireless communication that selects the access point as a communication partner of the SS wireless terminal
A mobility management device, wherein the access point is
Transmit / receive and modulate / demodulate frames with the SS wireless terminal.
Radio unit, the received field strength of the frame from the radio unit,
Separately, extended service area identification code and basic service area
Frame from the wired header of the frame.
The type of the game and the basic service area identification code
The transmitter and the frame received from the SS wireless terminal and server
Configure the following frame over-time of the exchange procedure processing by the over-time, or
First, the transmission and reception and modulation / demodulation of frames to communicate with the server
And a control unit for performing the control.

According to a second aspect of the present invention, in the mobility management apparatus for SS wireless communication, at the access point, the wireless unit has a wireless interface unit for transmitting / receiving and modulating / demodulating a frame for communicating with the SS wireless terminal; A reception field strength determination circuit for determining a reception field strength of a frame from the wireless unit; a header determination circuit for determining a frame type from a header of the frame from the wireless unit; and an identification code of an extended service area from a frame from the wireless unit Service area identification code determining circuit for determining the identification code of the basic service area from the frame from the radio section, and a reception FIFO memory for temporarily storing the frame from the radio section The transmission unit determines the type of the frame from the wired header of the frame from the control unit. Wired header discriminating circuit, a basic service area identifying sign discriminating circuit for discriminating the identification sign of the basic service area from the frame from the control unit, SS
Transmission F for temporarily storing a frame to be transmitted to the wireless terminal
A control circuit configured to control a process of forming a next frame of the exchange procedure process based on the frames received from the SS wireless terminal and the server and storing the next frame in the transmission FIFO memory; And a wired medium interface unit for performing transmission / reception and modulation / demodulation.

According to a third aspect of the present invention, the mobility management apparatus in the SS wireless communication comprises:
The wireless terminal and the access point perform point-to-point communication.

According to a fourth aspect of the present invention, in the mobility management apparatus for SS wireless communication, the access point transfers all frames to a server and performs point-to-multi communication.

The frame this arrangement mobility control apparatus in a SS wireless communication is received by the plurality of access points during the exchange procedure processing frame for in communicating valid data to and from the SS wireless terminal and the access point The server compares the magnitude of the received electric field strength of the SS wireless terminal and selects the access point to be the communication partner of the SS wireless terminal.

[0029] More specifically, it sends a part of the frame that SS wireless terminal transmits to the access point to the server, also, to send as a broadcast to the access point. S
The access point that has received the frame from the S wireless terminal adds the received field strength data from the SS wireless terminal to this frame or a response to the frame and transfers the data to the server, and the server receives the frame transferred from the access point. By comparing the electric field strengths, the frame exchange procedure processing is continuously performed with the access point through the access point having the highest received electric field strength.

[0030] That is, SS wireless terminal starts communication without being conscious of whether present in any of the basic service area, there is no need to bind to a particular access point. In addition, communication of valid data with the server is always performed through the access point having the highest received electric field strength.

[0031] Thus, the omitted redundant time required for re-binding processing when moving between basic service area, switching of the access point of the communication partner is performed quickly, without valid data is interrupted, the entire system Transmission efficiency is improved.

Further , since communication is performed with the access point having the maximum reception electric field strength, communication is performed with the best error rate at the position where the wireless communication terminal exists, and the transmission efficiency of the entire system is improved.

Furthermore, it eliminates the need for Sofutowaa executing the binding process, the configuration of the apparatus configuration and Sofutowaa is simplified, it is possible to simplify the apparatus size and processing scale,
Power consumption is reduced.

[0034]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment of a mobility management apparatus in SS wireless communication according to the present invention will be described in detail with reference to the drawings. FIG. 1 is a block diagram showing a configuration of a first embodiment of a mobility management device in SS wireless communication according to the present invention.

FIG. 1 shows an example of a wireless bridge of an access point.
Di AP. This wireless bridge AP is an SS wireless terminal
A radio unit 11 for transmitting / receiving and modulating / demodulating a frame with
The received field strength, type,
The identification code of the extended service area ESA (hereinafter referred to as ESID)
), The identification code of the basic service area BSA
(Hereinafter referred to as a BSID)
And the frame type and basic support from the frame's wired header.
Transmission unit 13 for determining the identification code of service area BSA
And the frame received from the SS wireless terminal and server
Therefore, the next frame of the exchange procedure processing is configured and
System that transmits, receives, modulates and demodulates frames that communicate with the
Control unit 14.

The radio unit 11 transmits / receives a frame for communication with the SS radio terminal and modulates / demodulates the frame.
/ F) section 111. The receiving unit 12 is a wireless unit 1
1 and a header discriminating circuit 122 for discriminating the type of the frame from the header of the frame from the radio unit 11.
And Also, an ESI for determining the identification code of the extended service area ESA from the frame from the radio unit 11
D discrimination circuit 123 and B from the frame from radio section 11
A BSID determining circuit 124 for determining the SID;
A receiving FIFO memory 125 for temporarily storing frames from No. 1 is provided.

The transmitting unit 13 includes a wired header discriminating circuit 131 for discriminating the type of the frame from the wired header of the frame from the control unit 14, and a BS from the frame from the control unit 14.
A BSID determination circuit 132 for determining an ID; and a transmission FIFO for temporarily storing a frame to be transmitted to the SS wireless terminal.
And a memory 133. In addition, the control unit 14
The next frame of the exchange procedure processing is constituted by the frame received from the SS wireless terminal and the server and the transmission FIFO
A microprocessor (MPU) 141 for controlling storage in the memory 133 and a wired medium I / F unit 142 for transmitting / receiving and modulating / demodulating a frame communicating with a server are provided.

Next, the operation of the first embodiment will be described. First, an operation when the wireless bridge AP shown in FIG. 1 receives a frame from a wireless communication terminal will be described.

In FIG. 1, when the wireless bridge AP receives a frame from a wireless communication terminal (not shown), the wireless I / F
The demodulation unit 111 demodulates the data, and the demodulated data
22, ESID determination circuit 123 and BSID determination circuit 1
24. Further, the demodulated data from the wireless I / F section 111 is stored in the reception FIFO memory 125. Further, the wireless I / F unit 111 outputs the received field strength data to the received field strength determination circuit 121, and stores the determined received field strength data in the reception FIFO memory 125.

The ESID determination circuit 123 determines whether the frame received from the demodulated output is addressed to the extended service area ESA to which the wireless bridge AP belongs. If it is not addressed to the extended service area ESA, the reception FIFO memory 1
Clear 25 stored data. BSID determination circuit 12
4 indicates that the frame received from the demodulated output is a radio bridge A
The MPU 141 determines whether or not the message is addressed to the basic service area BSA to which the P belongs. Header discrimination circuit 1
22 determines the type of the received frame from the demodulated output and notifies the MPU 141 of the type.

The MPU 141 determines the type of the received frame and the identification code (BSID) of the basic service area BSA.
Reconfigure the frame with reference to the IFO memory 125,
Again, the data is stored in the reception FIFO memory 125 and transferred to the server through the wired medium I / F unit 142. On the other hand, for a device that returns an ACK to a wireless communication terminal (not shown), the frame is reconfigured with reference to the reception FIFO memory 125, stored in the transmission FIFO memory 133, and stored in the transmission FIFO memory 133.
The signal is transmitted to a wireless communication terminal (not shown) through the / F section 111.

Next, the operation when the wireless communication terminal receives a frame from the server will be described. In the wireless bridge AP shown in FIG. 1, when a frame from the server is received, the frame is demodulated by the wired medium I / F unit 142, and the demodulated data is transmitted to the wired header discriminating circuit 131 and the BSID.
The transmission FIFO memory 1
33 is stored. The BSID determining circuit 132 determines from the demodulated data whether the received frame is addressed to the basic service area BSA belonging to the wireless bridge AP.

If the transmission FIFO memory 133 is not addressed to the basic service area BSA, the transmission FIFO memory 133 is cleared. The wired header determination circuit 131 determines the type of the received frame from the demodulated data, and notifies the MPU 141 of the type.
The MPU 141 determines the transmission FI according to the type of the received frame.
The frame is reconfigured with reference to the FO memory 133, stored again in the transmission FIFO memory 133, and transferred to a wireless communication terminal (not shown) through the wireless I / F unit 111.

Next, the operation of the SS communication network will be described. FIG. 2 is a diagram showing a format of a frame used in a frame exchange procedure in the first embodiment, and FIG. 3 is a diagram showing a configuration example of an SS communication network in the first embodiment.

In FIG. 1, FIG. 2 and FIG. 3, the radio communication terminal ST existing in the basic service area BSA1 performs all the radio bridges AP1 to AP3 in the extended service area ESA before processing the frame exchange procedure for valid data. Authenticates with the server to obtain permission to access the server through. First, the authentication request frame 21 in FIG. 2 is transmitted to the wireless bridges AP1 to AP3 by broadcasting with the wireless communication terminal ST.

All the wireless bridges AP1 to AP3 that have received the authentication request frame 21 add the received field strength data to this frame and transfer it to the server as the authentication request frame 22 in FIG. The ACK 23 to the authentication request frame in FIG. 2 is transmitted to the ST.
The server receives the authentication request frames 22 from the plurality of wireless bridges AP1 to AP3, and compares the received electric field strength when permitting the access of the wireless communication terminal ST.

In this comparison, the authentication response frame 24 in FIG. 2 is transmitted to the wireless bridge AP1 having the largest received electric field strength, and nothing is performed if the authentication response frame 24 is not permitted. Upon receiving the authentication response frame 24, the wireless bridge AP1 transfers the frame to the wireless communication terminal ST as an authentication response frame 25 in FIG. The wireless communication terminal ST sends an ACK2 to the wireless bridge AP1 to the authentication response frame in FIG.
Send 6.

Next, the wireless communication terminal ST is located in the basic service area BSA1 and performs SS wireless communication of valid data with the server.
, The RST-CTS-DATA-ACK frame exchange procedure is performed. First, the wireless communication terminal ST transmits the RST frame 27 in FIG. 2 to the wireless bridges AP1 to AP3 by broadcasting. All the wireless bridges AP1 to AP3 that have received the RST frame 27
The received field strength data is added to this frame and transmitted to the server as the RST frame 28 in FIG.

The server that has received the RST frames 28 from the plurality of wireless bridges AP1 to AP3 compares the received electric field strengths and determines whether the wireless bridge A has the largest received electric field strength.
The CTS frame 29 in FIG. 2 is transmitted to P1.
Wireless bridge AP1 receiving this CTS frame 29
, The DATA frame 211 in FIG. 2 is transmitted.
Wireless bridge A receiving this DATA frame 211
The data frame 212 in FIG. 2 is transferred to P1, and an ACK 213 to the DATA frame in FIG. 2 is transmitted to the wireless communication terminal ST. When there are a plurality of DATA frames, the frame exchange procedure processing of DATA-ACK is similarly repeated.

Next, a case where the second wireless communication terminal ST moves to another basic service area BSA1 to BSA3 will be described. In FIG. 3, the basic service area BSA1
The wireless communication terminal ST existing in the basic service area BS
A2 is shown. This wireless communication terminal S
There are two patterns for movement between the T basic service areas BSA1 to BSA3.

The first is when the wireless communication terminal ST moves before sending valid data, that is, before the RST-CTS-DATA-ACK frame exchange procedure processing, and the second is during sending valid data. That is, the RST-
CTS-DATA-ACK or RST-CTS-D
This is a case where the wireless communication terminal ST moves during execution of the ATA-ACK-DATA-ACK ... frame exchange procedure processing.

First, the first case will be described. In this case, it is the same as the case where the wireless communication terminal ST is resident in one of the basic service areas BSA1 to BSA3.
After moving to the basic service area BSA2, the radio communication terminal ST exchanges the RST-C with the radio bridge AP1.
The TS-DATA-ACK frame exchange procedure processing starts. First, the wireless communication terminal ST broadcasts, to the wireless bridges AP1 to AP3, the RST frame 2 in FIG.
7 and receives the RST frame 27, all the wireless bridges AP1 to AP3 send the received field strength data to the
It is transmitted as a T frame 28.

RST from wireless bridge AP1, AP2
The server that has received the frame 28 compares the received electric field strength, and transmits the CTS frame 29 in FIG. 2 to the wireless bridge AP2 having the largest received electric field strength. The wireless bridge AP2 that has received the CTS frame 29 transmits the CTS frame 210 in FIG. 2 to the wireless communication terminal ST. The wireless communication terminal ST that has received the CTS frame 210 transmits the DATA in FIG.
The frame 211 is transferred, and an ACK 213 to the DATA frame in FIG. 2 is transmitted to the wireless communication terminal ST.
If there are multiple DATA frames,
The TA-ACK frame exchange procedure is repeated.

Next, the second case will be described. FIG.
FIG. 5 is a diagram showing a frame exchange procedure in the first embodiment. 1 to 4, the radio communication terminal ST communicates with the radio bridge AP1 through the RST-CTS-DATA-
During the execution of the ACK frame exchange procedure, the mobile station moves from the basic service area BSA1 to the basic service area BSA2. First, the wireless communication terminal ST broadcasts to the wireless bridges AP1 to AP3 at time T in FIG.
1, the RST frame 27 in FIG. 2 is transmitted.

Upon receiving the RST frame 27, the wireless bridges AP1 and AP2 send a signal to the server at time T in FIG.
At 2 and T3, the received field strength data is added to this frame and transmitted as the RTS frame 28 in FIG. The server that has received the RTS frames 28 from the wireless bridges AP1 and AP2 compares the received electric field strengths, and sends the CTS frame 29 shown in FIG. 2 to the wireless bridge AP1 having the largest received electric field strength at time T4 in FIG. Send Wireless bridge AP1 receiving this CTS frame 29
Transmits to the wireless communication terminal ST at the time T5 in FIG. 4 to the CTS frame 210 in FIG.

Here, the wireless communication terminal ST starts moving, and the wireless bridge AP1 inside the basic service area BSA2.
If the wireless bridge AP2 has moved closer,
The wireless communication terminal ST that has received the CTS frame sends a signal to the wireless bridge AP1 at time T6 in FIG.
The ATA frame 211 is transmitted. DATA frame 2
The wireless bridge AP1 that has received the data frame 11 in the data frame 2 shown in FIG. 2 at time T7 shown in FIG.
12 is transferred to the wireless communication terminal ST in FIG.
The ACK 213 for the TA frame is transmitted.

Further, since the wireless bridge AP2 also has the wireless communication terminal ST located inside the basic service area BSA2 and can normally receive the DATA frame 211, the wireless bridge AP2 sends the WACK frame 214 in FIG.
Send The server receiving the DATA frame 212 and the WACK frame 214 compares the received electric field strengths,
Since the destination wireless bridge AP2 has a large received electric field strength, the BSA switching frame 216 in FIG. 2 is transmitted to the wireless bridges AP1 and AP2 at time T9 in FIG.
When the wireless bridge AP1 from which the wireless communication terminal ST has received the BSA switching frame 216 has received the DAT frame 212 from the wireless communication terminal ST,
At time T10 in FIG. 4, the WACK frame 21 in FIG.
4 is transmitted.

When the wireless bridge AP 2 to which the wireless communication terminal ST has received the BSA switching frame 216 receives the DATA frame 212 from the wireless communication terminal ST, the wireless bridge AP 2 sends the data to the server at time T 10 in FIG. , FIG. 2
Transfers the DATA frame 212 in the wireless communication terminal S
An ACK 213 for the DATA frame in FIG. As a result, the wireless bridges AP1 to AP3 with which the wireless communication terminal ST communicates are switched.

Next, a second embodiment will be described. FIG. 5 is a diagram for explaining a frame exchange procedure in the second embodiment. The second embodiment shown in FIG.
When T moves to another basic service area BSA1 to BSA3, valid data is being transmitted, that is, the RST
The figure shows the frame exchange procedure processing when the wireless communication terminal ST moves during the execution of the frame exchange procedure processing of -CTS-DATA-ACK-DATA-ACK ..., and shows the part after DATA-ACK. I have.

Here, the second embodiment differs from the first embodiment in that the frame exchange procedure
In the DATA-ACK phase, the wireless communication terminal ST and the wireless bridges AP1 to AP3 perform point-to-point communication, whereas the wireless bridges AP1 to AP3 communicate.
3 transfers all frames to the server, so that the wireless communication terminal ST and the wireless bridges AP1 to AP3
Perform two-to-multipoint communication.

During the execution of the RST-CTS-DATA-ACK frame exchange procedure, the wireless communication terminal ST starts to move, and moves inside the basic service area BSA2, but to a position where the wireless bridge AP1 is closer to the wireless bridge AP2. In this case, the wireless communication terminal ST receiving the CTS frame broadcasts the wireless bridges AP1 to AP3.
Then, at time T6 in FIG. 5, the DATA frame 212 in FIG. 2 is transmitted. Upon receiving the DATA frame 212, the wireless bridges AP1 and AP2 receive the data at time T7 in FIG.
At T8, the data frame 2 in FIG.
Transfer No. 12.

The server that has received the DATA frame 212 compares the received electric field strength and transmits an ACK 215 to the DATA frame shown in FIG. 2 to the wireless bridge AP1 having the largest received electric field strength at time T9 in FIG. I do. Upon receiving the ACK 215 to the DATA frame, the wireless bridge AP1 sends a signal to the wireless communication terminal ST in FIG.
ACK to DATA frame in FIG. 2 at time T10 in the middle
23 is transmitted. Here, when the wireless communication terminal ST moves further and becomes closer to the wireless bridge AP2 than the wireless bridge AP1, the wireless communication terminal S receiving the ACK
T again broadcasts the wireless bridges AP1 to AP3
Then, at time T11 in FIG. 5, the DATA frame 212 in FIG. 2 is transmitted.

The wireless bridges AP1 and AP2 that have received the DATA frame 212 transmit the data at times T12 and T1 in FIG.
In step 3, the data frame 212 in FIG.
To transfer. The server that has received the DATA frame 212 compares the received electric field strengths, and sends a signal to the wireless bridge AP2 having the strongest received electric field strength at time T14 in FIG.
Transmits the ACK 215 to the DATA frame in FIG. Upon receiving the ACK 215 for the DATA frame, the wireless bridge AP2 sends a signal to the wireless communication terminal ST as shown in FIG.
ACK to DATA frame in FIG. 2 at time T10 in the middle
213 is transmitted.

[0064]

As is apparent from the above description, the present invention
According to the mobility management apparatus in the SS wireless communication, the reception electric field strength of a frame received by a plurality of access points during a frame exchange procedure performed when valid data is communicated between the SS wireless terminal and the access point Since the server compares the sizes of the access points and selects an access point to be a communication partner of the SS wireless terminal, redundant time required for reconnection processing when moving between basic service areas is omitted. That is, the switching of the access point of the communication partner is performed quickly, the effective data is not interrupted, and the transmission efficiency of the entire system is improved.

Since communication is performed with the access point having the maximum reception electric field strength, communication is performed with the best error rate at the position where the wireless communication terminal exists. In other words, the transmission efficiency of the entire system is improved, and software for executing the combining process is not required, the configuration of the device and the configuration of the software are simplified, and the configuration of the device and the configuration of the software are simplified. The size can be simplified and the power consumption can be reduced.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a first embodiment of a mobility management device in SS wireless communication of the present invention.

FIG. 2 is a diagram showing a format of a frame used in a frame exchange procedure in the first embodiment.

FIG. 3 is a diagram illustrating a configuration example of an SS communication network in the first embodiment.

FIG. 4 is a diagram showing a frame exchange procedure in the first embodiment.

FIG. 5 is a diagram for explaining a frame exchange procedure in the second embodiment.

FIG. 6 is a diagram illustrating a configuration example of a conventional SS communication network.

FIG. 7 is a diagram showing a format of a frame used in a frame exchange procedure in a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 12 Receiving part 13 Transmitting part 14 Control part 111 Wireless I / F part 121 Received electric field strength discriminating circuit 122 Header discriminating circuit 123 ESID discriminating circuit 124 BSID discriminating circuit 125 Receiving FIFO memory 131 Wired header discriminating circuit 132 BSID discriminating circuit 133 Transmitting FIFO memory 141 MPU 142 Wired media I / F

Claims (4)

(57) [Claims] 1. A SS wireless terminal, the access point of a wireless bridge that connects the SS wireless communication network and a wired communication network, a server, made from a wired communications medium connecting a plurality of access points and the server, and the SS wireless terminal wherein Valid with access point
In the process of exchanging frames for data communication
Of the frames received by the plurality of access points
The server compares the magnitude of the received electric field strength, and
Select the access point with which the wireless terminal communicates
A mobile management device in SS wireless communication that performs transmission / reception of frames with an SS wireless terminal and modulation / demodulation as the access point.
Line section, received electric field strength, type, extension of frame from the radio section
Determine service area identification code and basic service area
The frame type and basic service from the frame's wired header.
A transmission unit for determining a service area identification code, and a frame received from the SS wireless terminal and the server.
Therefore, the next frame of the exchange procedure processing is configured and
It performs transmission / reception and modulation / demodulation of frames communicating with the server.
And a control unit for the SS radio communication.
Equipment. 2. The access point, wherein the wireless unit has a wireless interface unit for transmitting / receiving and modulating / demodulating a frame for communicating with the SS wireless terminal, and the receiving unit determines a received electric field strength of the frame from the wireless unit. A received electric field strength discriminating circuit, a header discriminating circuit for discriminating a frame type from a header of the frame from the radio unit, and an extended service area discriminating code discriminating unit for discriminating an extended service area discriminating code from the frame from the radio unit. A circuit; a basic service area identification code determination circuit for determining an identification code of a basic service area from a frame from the radio unit; and a reception FI for temporarily storing a frame from the radio unit.
A transmitting section, wherein the transmitting section includes: a wired header determining circuit that determines a type of the frame from a wired header of the frame from the control section; and a basic service area that determines an identification code of the basic service area from the frame from the control section. An identification code discriminating circuit; and a transmission FIFO memory for temporarily storing a frame to be transmitted to the SS wireless terminal. The control unit determines a next frame of the exchange procedure processing by a frame received from the SS wireless terminal and a server. 2. The SS wireless communication according to claim 1, further comprising: a control circuit configured to perform control to store the data in the transmission FIFO memory; and a wired medium interface unit that performs transmission / reception and modulation / demodulation of a frame communicating with the server. 3. Mobility management device in. 3. In the frame exchange procedure processing, S
The mobility management device for SS wireless communication according to claim 1 or 2, wherein the S wireless terminal and the access point perform point-to-point communication. Wherein said access point, SS according to claim 1, 2 or 3, wherein the communication is performed to transfer all frames to the server in a point-to-multipoint
Mobility management device in wireless communication.