JP2003332971A - Communication method for wireless network and wireless network system - Google Patents

Communication method for wireless network and wireless network system

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Publication number
JP2003332971A
JP2003332971A JP2002133903A JP2002133903A JP2003332971A JP 2003332971 A JP2003332971 A JP 2003332971A JP 2002133903 A JP2002133903 A JP 2002133903A JP 2002133903 A JP2002133903 A JP 2002133903A JP 2003332971 A JP2003332971 A JP 2003332971A
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JP
Japan
Prior art keywords
signal
station
wireless
wireless station
pattern
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
JP2002133903A
Other languages
Japanese (ja)
Inventor
Kazuo Hasuike
Bandyopadhyay Somprakash
Tetsuo Ueda
ソンプラカッシュ・バンディオパダイ
哲郎 植田
和夫 蓮池
Original Assignee
Advanced Telecommunication Research Institute International
株式会社国際電気通信基礎技術研究所
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Application filed by Advanced Telecommunication Research Institute International, 株式会社国際電気通信基礎技術研究所 filed Critical Advanced Telecommunication Research Institute International
Priority to JP2002133903A priority Critical patent/JP2003332971A/en
Publication of JP2003332971A publication Critical patent/JP2003332971A/en
Application status is Pending legal-status Critical

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Abstract

(57) [Summary] [PROBLEMS] To perform wireless communication in a correct direction almost without being affected by an interference signal from another station, and to greatly reduce overhead compared to the second conventional example. SOLUTION: Each wireless station 1 has a variable beam antenna 10
1 and broadcasts its own station ID to each wireless station 1 in its service area using an omni pattern.
Is transmitted, a beacon signal is received using the rotating sector pattern, and an azimuth angle, a signal strength level, and a wireless station ID of the beacon signal are detected. The azimuth and signal strength level for each wireless station 1 are stored in the database memory 154 as an azimuth and signal strength level table (AS table), and are indicated by the AS table when transmitting the packet signal to the destination wireless station. The packet signal is routed by transmitting the packet signal to the destination wireless station using the azimuth sector pattern.

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention provides a plurality of radio stations.
For example, in a wireless network such as a wireless LAN
For example, an ad hoc wireless network
Communication method for wireless network such as network and wireless
Regarding network systems. [0002] Unspecified temporarily gathered in a specific area
Ad hoc wirelessly supports communication between large numbers of people
In wireless networks, for example, Internet routers
Because there is no infrastructure like equipment
Users in the network cooperate to relay packets
Need to do routing. Ad hoc wireless network routines
For example, in prior art document 1 “DB Johnson, e
t al., "Dynamic Source Routing in Ad Hoc Wireless
Networks ", in book on" Mobile Computing ", Chapter
5, pp.153-181, Kluwer Academic Publishers, 1996 ''
Sends route search packets to obtain route information
(Hereinafter referred to as a first conventional example) has been proposed.
You. However, in the first conventional example, the omnidirectional
Co-channel interference
Likely to occur and the bit error rate (BER)
Power consumption during packet transmission and reception
The load on the battery of the terminal device increases.
There was a problem. [0005] In order to solve this problem, Japanese Patent Laid-Open Publication No.
In Japanese Patent Application Laid-Open No. 1-244983, “a plurality of radio stations
For wireless networks that perform packet communication on the Internet
In the serving method, the service of the plurality of radio stations is provided.
Signal for each azimuth angle for each radio station in the swell area
A power-to-interference-noise power ratio (hereinafter referred to as SINR) is predicted.
Measured and stored in a storage device as a SINR table,
When transmitting a packet to a destination wireless station, the SINR
The first hop radio station is determined based on the table, and
A beam is formed for the determined first hop radio station.
Control the variable beam antenna to transmit packets.
Route the packet signal by transmitting
(Hereinafter referred to as a second conventional example) have been proposed. In this second conventional communication method,
Not only start communication but also directivity and adaptive control type antenna
To achieve effective routing using
The wireless station effectively sets its transmit direction
Must know how to send
No. Therefore, each station periodically collects its neighbor information.
At the same time as forming the above-described SINR table,
In order to form the INR table, any radio station
The following steps are performed periodically and asynchronously. (I) Whenever a wireless channel is available,
The line station sets omni-patterns for nearby radio stations.
Transmit the up packet signal. (Ii) The radio station scans its directional antenna and
Azimuth angle request (RQ: ReQuest) packet signal
The data is sequentially transmitted in all directions in the form of directional broadcast communication. For example
This is performed at intervals of 30 degrees, and the entire space of 360 degrees is sequentially
If covered, 12 directional RQ packets
Signal will be generated. No RQ packet signal
It contains the line station ID and the azimuth information of the broadcast. (Iii) Setup packet signal from source wireless station
Signal, each radio station adjacent to the source radio station
Wait in the receive mode for a predetermined time and send
Omnidirectional broadcast by the original radio station (sequential
RQ packet signal) is confirmed. As a result,
At this point, each adjacent wireless station is
Receiving all generated RQ packet signals for all directions
Is guaranteed. In other words, each adjacent radio
The station has an SNR that indicates the SINR for the azimuth of the transmitting wireless station.
Fill in all the columns for each adjacent wireless station in the INR table
Can be accumulated and the directionality RQ from the source radio station
The source radio station in that direction by the packet signal
Is determined. (Iv) Each neighboring radio station responds with this information (RE: REpl
y) Transmit to the source wireless station as a packet signal. R
The E packet signal is processed as a data packet.
This information is sent from all stations adjacent to the source station.
Is received, the SINR table is completed.
Become. According to the second conventional method, indoor and outdoor
Information of neighboring wireless stations can be collected periodically
And use this information to directivity and adaptive
Making communication methods with teners more effective
Has advantages. [0008] However, the interference state
The situation changes easily due to the bursty nature of the packet
Therefore, using the SINR table for angle prediction
May not be appropriate. That is, FIG.
Two typical examples of the problem in the conventional example are shown.
I have. Here, the wireless station 100a corresponds to the wireless station 100b.
Setup packet signal and 12 RQ packets
And the wireless stations 100c and 100d
100a outside the service area 100A
Is assumed. Under these circumstances, the radio station 100c
And 100d are sections after the 210 degree RQ packet signal.
Data from the data pattern and adaptive control beam pattern
Start communication. In this case, a 210 degree RQ packet
SIN of RQ packet signal whose signal SINR is 270 degrees
May exceed R. In other words, transmission signals from other stations
Signal is affected by the
If the SINR does not indicate the optimal SINR
Case exists. This situation is caused by each of the wireless stations 100c and 100c.
There is also a problem that it changes with the movement of d. Further, the communication method according to the second conventional example is
The question is that large overhead is needed.
There is a title. That is, the setup packet signal and
The above-mentioned SINR at the transmitting radio station of the RQ packet signal
To build the table, all neighboring stations must
Always use RE packet signal for received SINR value
That is, as a data packet of four handshakes
Must respond. For example, one radio station
-Up packet signal and 12 RQ packet signals
(In the case of 30-degree intervals)
Generation of SINR tables for four adjacent wireless stations in the rear
If trying, this station will have a total of 29 packet signals
(4 radio station setup signals, 12 RQ packets
Signal, RTS / CTS / DATA / ACK signal)
Consume. If there are 12 wireless stations around, 6
One packet signal is generated. That is, SINR
To generate a table, the operation at each station
Being very busy, sending and receiving data signals that should be sent
In addition to the very large overhead mentioned above
There was a problem that required. [0010] An object of the present invention is to solve the above problems, and
Correct direction with almost no interference from the station
Wireless communication can be performed by using the second conventional example.
Wireless network that can significantly reduce overhead
Communication method and wireless network system for communication
Is to do. [0011] A wireless network according to the present invention.
The communication method for the work includes a plurality of radio stations,
For wireless networks that perform packet communication between line stations
In the communication method, each of the above radio stations is an omnidirectional omni
Pattern and sector pattern with predetermined azimuth angle width
And rotation to scan while rotating the above sector pattern
Of the radiation pattern using at least the sector pattern
Equipped with a variable beam antenna that performs control,
Omni pattern is used for each wireless station in the service area
To send a beacon signal including the own station ID by broadcast
Using the rotating sector pattern
The beacon signal is received, and the azimuth and
By detecting the signal strength level and the radio station ID,
Each wireless station in the service area of the plurality of wireless stations
The azimuth and signal strength level.
Storing in the storage device as a bell table;
When transmitting the packet signal to the destination radio station, the azimuth
And the destination indicated by the signal strength level table
The destination radio using the sector pattern of the azimuth of the line station.
By transmitting a packet signal to the station,
Routing the signal
And [0012] In the communication method for the wireless network,
In the RTS / CTS access control method, the source
Perform wireless data communication between the wireless station and the destination wireless station
Communication method for transmitting a signal to
And the destination radio indicated by the signal strength level table
The destination using a sector pattern that directs the beam to the station
An RTS signal is transmitted to the radio station, and the destination radio station
The RTS signal is received using the rotating sector pattern and
When the wireless station ID in the RTS signal is detected,
Azimuth and signal strength based on wireless station ID of source wireless station
Beeper to the source radio station indicated by the level table.
Change to the sector pattern to which the
After transmitting the CTS signal using the above sector pattern
Transmit to the source radio station, and the source radio station
By receiving the CTS signal using the turn, the destination
Establish a radio link with the radio station, and then
And the destination radio station both use the above sector pattern.
Performing transmission and reception of data signals and ACK signals
Sign. Further, communication for the wireless network
In the method, according to the RTS / CTS access control scheme
Performs wireless data communication between the source wireless station and the destination wireless station.
Communication method for performing wireless communication, wherein
Has an adaptive control pattern using a predetermined adaptive control method.
Control of radiation pattern of variable beam antenna
The source radio station determines the azimuth and signal strength level.
The beam to the destination radio station indicated by the
RTS to the destination wireless station using the
Transmit the signal, and the destination wireless station
Receiving the RTS signal using the
When the station ID is detected, the radio station I of the source radio station is detected.
By azimuth and signal strength level table based on D
Sector beam pointing beam to the source radio station indicated
RTS signal by changing to adaptive control pattern through turn
After receiving the CTS signal using the above adaptive control pattern.
Signal to the source wireless station, and the source wireless station
-Change the pattern to the above adaptive control pattern and change the CTS
By receiving the signal, the radio link with the destination radio station
And then the source and destination radio stations
Data signal and ACK using the adaptive control pattern
Signal transmission and reception are performed. [0014] A wireless network system according to the present invention.
Has a plurality of wireless stations, and performs packet communication between each wireless station.
In the wireless network system to perform, each of the above wireless stations
Has an omni-directional omni pattern and a predetermined azimuth width.
Sector pattern to rotate and the above sector pattern
Rotating sector pattern while scanning at least
Variable beam antenna to control radiation pattern using
And each radio station within its own service area
Include own station ID in broadcast using two patterns
Transmitting means for transmitting a beacon signal, and a rotating sector pattern
The beacon signal is received using the
Detects signal azimuth, signal strength level and radio station ID
The service area of the plurality of radio stations
Azimuth and signal strength level for each radio station in the
The angle and the signal strength level table are stored in the storage device.
Receiving means and transmitting a packet signal to a destination wireless station.
The azimuth and signal strength level table.
The azimuth sector pattern of the destination station
Transmitting a packet signal to the destination wireless station.
And routing routines for routing packet signals
And a switching means. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described with reference to the drawings.
An embodiment will be described. FIG. 1 shows an embodiment according to the present invention.
Plurality of wireless stations 1 showing the configuration of a wireless network
-1 to 1-9 (generally denoted by reference numeral 1)
FIG. 2 is a block diagram showing the configuration of each wireless station 1 in FIG.
It is a lock figure. The wireless communication system according to this embodiment is, for example,
Packet of ad hoc wireless network such as wireless LAN
Wireless communication system, and each wireless station 1
Has an omni-directional omni pattern and a predetermined azimuth width.
Sector pattern to rotate and the above sector pattern
Rotating sector pattern while scanning at least
Variable beam antenna to control radiation pattern using
(I) each station within the service area of its own station.
Broadcast to line station 1 using omni pattern
Transmits a beacon signal including its own station ID in (ii) rotation
Receiving the above beacon signal using a sector pattern,
Azimuth angle, signal strength level and radio station I of the beacon signal
By detecting D, the plurality of wireless stations 1
Azimuth and signal for each wireless station 1 in the service area
The strength level is stored in the azimuth and signal strength level table (hereinafter
Below, it is called an AS table. AS is Angle-Signal S
Abbreviation of trength. ) As the database memory 15
And (iii) transmit the packet signal to the destination wireless station.
The azimuth indicated by the AS table
A packet is sent to the destination wireless station using the sector pattern.
By transmitting a packet signal, the packet signal can be routed.
It is characterized by performing. In the wireless communication system of this embodiment,
As shown in FIG. 1, a plurality of wireless stations 1
Each radio station 1 has a variable beam antenna 10
Determined by parameters such as gain 1, transmission power, and reception sensitivity
Service area, and this service area
Service area can perform packet communication within
When performing packet communication with an external radio station 1, the service
Packet data using the wireless station 1 in the rear as a relay station
To the desired destination wireless station 1 by relaying
Transmit data. That is, each wireless station 1
Router device for routing
It operates as a relay station or a destination terminal. Next, referring to FIG.
The configuration will be described. In FIG. 2, the wireless station 1
The variable beam antenna 101 and its directivity are controlled.
Radiation pattern control unit 103 and circulator 10
2, data packet transmitting section 140 and data packet
Data packet transmitting / receiving section 104 having receiving section 130
, A traffic monitor unit 105, and a line control unit 106
And an upper layer processing unit 107. An upper layer for processing data to be transmitted and received
Communication in packet format generated by the processing unit 107
Transmission signal data for transmission via the transmission buffer memory 142.
Input to the modulator 143, and the modulator 143
The carrier signal of the line frequency is converted to a CD by the spread code generator 160.
The spreading code for a predetermined communication channel generated by the MA method is
And transmit the signal according to the input transmission signal data for communication.
High-frequency transmitter that performs spread spectrum modulation and modulates the transmitted signal.
144. The high-frequency transmitter 144 receives the input transmission.
After performing processing such as amplification on the
From the variable beam antenna 101 via the
To the wireless station 1. On the other hand, the variable beam antenna
For the communication channel in the packet format received by the
The signal is transmitted to the high-frequency receiver via the circulator 102.
131 and the high-frequency receiver 131
After performing processing such as low noise amplification on the
Output to the adjuster 132. The demodulator 132 receives the input signal.
CDMA signal is generated by spread code generator 160
Spectrum inverse using the spread code for the communication channel
Demodulate by spreading and receive demodulated received signal data
Upper layer processing device 107 via the buffer memory 133
As well as traffic for traffic monitoring.
Output to the clock monitor unit 105. In this embodiment, the variable directivity antenna is
The variable beam antenna 101 is a plurality of antennas.
Radiation pattern control unit 103 for controlling the element and its directivity
And more specifically, wireless
The excitation element to which the signal is fed and the specified distance from this excitation element
Multiple units that are provided only at a distance and are not supplied with radio signals
Parasitic elements and the variable connected to each of these parasitic elements
An array antenna consisting of a reactance element
Change the reactance value of each variable reactance element
Changes the directional characteristics of the array antenna.
The Iwayu disclosed in the following prior art documents
ESPAR antenna can be used. In this embodiment
In this case, the variable beam antenna 101 is, for example, a predetermined
The direction of the main beam having the beam width is changed during a predetermined scan.
It can be changed by electrical control at intervals.
It works by selectively setting turns. (I) Omnidirectional omni pattern. (Ii) A sector pattern having a predetermined azimuth angle width. (Iii) The sector pattern is set to a predetermined azimuth angle (for example,
Rotating sector pattern that scans while rotating every 30 degrees)
Or (Iv) For example, an adaptive control method such as a known steepest gradient method is used.
The main beam of the variable beam antenna 101 is
Adaptive control pattern for pointing in the direction and nulling in the direction of the interference wave
turn. (A) Prior art document 2 “Takao Ohira,” Consumer Adaptive Antenna
Towards the Realization ", 1999, The Kansai Branch of the Institute of Electrical Engineers of Japan
Symposium, "Recent Microwave and Millimeter Wave Technologies",
S8-1 pp. S41, November 14, 1999 ",
(B) Prior art document 3 "Takao Ohira et al.," Microwave signal
Beam Formation by Electronic Processing and Electronically Controlled Director
(ESPAR) Proposal of Antenna ", Institute of Electronics, Information and Communication Engineers
Technical Report, AP99-61, SAT99-61, p
p. 9-14, July 1999 "and (c) prior art text
4 "Tetsu Tano et al.," M-CMA: Microwave Signal Processing
Digital Signal Processing Algo for Adaptive Beamforming with CDMA
Rhythm ”, IEICE Technical Report, AP99-
62, SAT99-62, pp. 15-22, 1999
July ". (D) Prior art document 5 “T. Ohira et a
l., "Electronically steerable passivearray radiato
r antennas for low-cost analog adaptive beamformin
g, "2000 IEEE International Conference on Phased Ar
ray System & Technology pp. 101-104, Dana point, C
alifornia, May 21-25, 2000 ". (E) JP-A-2001-
24431 gazette. Note that the variable beam antenna 101
For example, a known phased array antenna
May be used. The traffic monitor unit 105 has a search engine
152, an update engine 153, and a database memo.
And a packet transmission / reception control process described later.
And the wireless station 1 sends a packet to another wireless station 1.
Determine the communication channel to be used in communication and determine
The designated data of the spreading code corresponding to the
It is sent to the spreading code generator 160 via the line control unit 106.
With this, the spreading code generator 160
Control to generate the corresponding spreading code,
Specified time slot corresponding to the specified communication channel.
Data transmission timing control unit via the line control unit 106
141, the transmission timing control unit 141
Is the transmission for the communication channel by the transmission buffer memory 142.
By controlling the writing and reading of signal data,
Time slot corresponding to the transmission signal for the communication channel
Control to be sent. Search engine for traffic monitor 105
152 is a database under the control of the management control unit 151.
Search the data in the memory 154 and manage the searched data.
Reply to the processing control unit 151. Also, the update engine 153
Is a database memory under the control of the management control unit 151.
The data in 154 is updated. In addition, database
The memory table 154 includes an AS table and a routing table.
And a wireless station table. The data stored in the database memory 154 is
As shown in FIG. 4, the service table of the own station is
Azimuth and signal strength level for each adjacent radio station in the
Information for packet transmission / reception control described later.
Created and updated. In addition, the routing table
Exists in the ad hoc wireless network
For each radio station, the ID of the first hop radio station and the
The number of packets and the update time are
Store based on the data of the In addition, the radio station
Cables exist in the ad hoc wireless network.
The ID of the current wireless station is
Store based on the data of the Used in the packet communication system of this embodiment
The packet data has the format shown in FIG.
Have. That is, the packet data includes a destination ID,
Packet type (beacon, RTS, CTS, DATA
), Its own ID, and data (data in the upper layer).
And the like). Next, the MAC communication protocol used in this embodiment will be described.
The protocol will be described below. None according to this embodiment
1 that performs wireless communication with each other in a line communication network
A set of radio stations 1 moves around in a two-dimensional closed space,
Are assumed to share the same wireless communication channel. Each nothing
The line station 1 has the four radiation patterns described above, for example,
Equipped with a variable beam antenna 101 that is an ESPAR antenna
You. Each radio station 1 can execute either transmission or reception at one time
It is possible to perform multiple transmissions and receptions with one wireless station 1
Can not. IEEE 802.11 MAC protocol
By standard, RTS / CTS / DATA / ACK access
Highly reliable data communication is guaranteed using the control method
However, in the method of this embodiment, the access control method
To form an AS table based on
Is added with additional command and response signals. Follow
Data communication is a periodic, AS table generation phase
It is executed in the interval. In addition, each frame has a training
And the transmit sequence is added to the
Beam and null control and transition to adaptive control mode
Enabled. FIG. 5 shows a four-way handshake according to this embodiment.
9 shows an example of use of the antenna mode of Jake. Adaptive system
Your pattern can track a moving device,
Beam and null are formed if no packet signal is received
Can not be done. Therefore, RTS transmission and RTS / CTS reception
In the beginning of the communication, omni patterns and sector patterns
Turns are used. Further, the waiting radio station 1 has a directivity R
Since it does not know from which direction the TS signal comes,
A rotating sector pattern is used. According to this embodiment
The transmission time of the RTS signal in the case of the AS table is the second
SINR table used in MAC protocol according to conventional example
Note that this is twice the RTS signal transmission time
It takes care. In addition, transmission of the RTS signal and transmission of the CTS signal
The direction of the beam of the sector pattern in reception is shown in FIG.
From the AS table. Next, the ad hoc wireless network shown in FIG.
Type of radiation pattern at each radio station used in the network
And a timing chart showing a wireless communication protocol.
The control pattern of FIG. 5 will be described in detail below. Ma
And the source wireless station does not
Using a sector pattern that directs the beam to the destination radio station.
While transmitting an RTS signal to the destination radio station,
The radio station receives the RTS signal using the rotating sector pattern.
When the wireless station ID in the RTS signal is detected
Is the azimuth angle based on the wireless station ID of the source wireless station.
And no source indicated by the signal strength level table
Adaptive control via sector pattern to direct beam to line station
Control pattern and receive the RTS signal. Then
The destination wireless station continues to use the adaptive control pattern
While transmitting the CTS signal to the source radio station,
The station switches from the sector pattern to the adaptive control pattern
By changing and receiving the CTS signal, the destination radio station
Establish a wireless link with Then, the source radio station and
Both destination wireless stations use the above adaptive control pattern to transmit data.
Transmission and reception of the data signal and the ACK signal. That is,
The source wireless station uses the adaptive control pattern to
While transmitting, the destination station adapts the transmitted data signal.
Receive using the response control pattern. Next, the destination radio station
Is ACK as a confirmation signal that the data signal has been received.
Signal to source wireless station using adaptive control pattern
Transmit, while the source radio station adaptively controls this ACK signal.
Receive using the control pattern. The control pattern according to the present embodiment shown in FIG.
In the pattern, from the reception of the RTS signal, the sector pattern
Radiation pattern of the antenna changed from
Using the turn at the destination and source radio stations
But does not use the adaptive control pattern,
You may use only. Using the AS table of FIG.
In the proposed MAC protocol to use, each radio
The station 1 periodically executes the following steps. (I) Radio having adjacent radio stations 1-i, 1-j, 1-k
The station 1-n always performs the reception mode using the rotating sector pattern.
Waiting in the mode. In the rotating sector pattern, wireless
Station 1-n controls its variable beam antenna 101,
Signals received in all directions
In the form of sexual reception. In the present embodiment, 30
12-sector pattern with beam width
And scans all 360 ° azimuths. (Ii) Whenever a wireless channel is available,
The wireless station 1 transmits the beacon signal using the omni pattern.
Transmit to nearby wireless stations. This proposed MAC
In the protocol method, as shown in FIG.
Packet signals are sequentially transmitted as beacons. Beeco
The first packet signal of the
Beacon signal is being transmitted by the receiving wireless station
It is helpful in detecting whether or not it is. Next, the receiver
Receiving and decoding the second packet signal of the remote control. Bee
The second packet signal of the controller includes the radio station ID.
You. Here, the time to rotate in all 12 directions is one packet.
Must be set shorter than the duration of the reset signal. (Iii) In the rotating sector pattern, the wireless station 1-i is
In one rotating sector pattern during rotation of another
Detect first packet of beacon from wireless station 1-n
Then, the wireless station 1-i detects the detected sector pattern.
Stops rotating at the
Receive a second packet. Signal strength of second packet
The level is measured, and the wireless station ID of the wireless station 1-i is decoded.
Azimuth angle of the detected sector pattern
Azimuth angle of the adjacent wireless station 1-i that transmitted the remote control signal.
You. (Iv) The wireless station 1-n stores the AS table of the wireless station 1-n.
Write the detected information in the column of the wireless station 1-i.
You. In FIG. 4, the azimuth angle ANGLEn, i (t) is
Radio of the received sector pattern at that instant t
Azimuth in the direction from station 1-i to radio station 1-n, S
IGNALn, i (t) is the sector of wireless station 1-n
Signal level received from the wireless station 1-i in the pattern.
It is. (V) The wireless stations 1-n are the wireless stations 1-i, 1-j, 1-k
From the wireless station 1
-N of the wireless stations 1-i, 1-j, 1-k in the AS table
The entire column is accumulated and updated and stored. By the way, in the second conventional protocol,
Means that any radio station 1-n transmits a setup signal
The formation of the SINT table based on the start is started. here
The azimuth angle for the transmitter must be different from the angle for the receiver.
Broadcast from the wireless station 1-n.
Received radio (eg without 12 RQ packet signals)
Angle prediction by rotating sector pattern at station is appropriate
Not. Therefore, 12 RQ packets according to the angle information
Set up with RE packet signal as well as signal
Packet signal and 12 RQ packet signal receiver
It is also necessary to use the transformation of these angle information. Ma
Many setup packets from any peripheral radio station.
Radio station receiving a RQ signal and 12 RQ packet signals
Is transmitted to all adjacent wireless stations via the RE packet signal.
There was a problem that they had to respond. On the other hand, the communication processor according to the present embodiment
In Tokor, each AS table stores the beacon receiving radio station.
The rotating sector pattern is
Omnidirectional beacon angle prediction
It is possible. Different transmission power of each radio station
The problem of asymmetric links is to add transmit power information to the beacon.
It can be avoided by adding. As a result, 1
Without two RQ packet signals or RE packet signals
Send only two packet signals as beacon signals
Just trust me. In addition, this beacon signal
Radio station, each station behaves
You only need to send the con signal once. In other words, each wireless
Stations send neighbors with only one beacon signal
To make every wireless station predict the angle received.
It is possible to transmit beacon signals by the number of neighboring wireless stations.
Need not be. Further, the MA according to the proposed embodiment is
In the C protocol, each wireless station predicts the angle of an adjacent wireless station
Signal strength level instead of SINR when link quality
According to the present embodiment for use as a parameter of
The MAC protocol is a protocol according to the second conventional example.
Of interference in SINR table for each azimuth angle
Can be avoided. Beacon packet signal from each wireless station
Are transmitted at the same transmission interval. In this case, each radio station
Randomly chooses the transition timing of the beacon signal
Even if multiple beacon signals are transmitted at the same time,
The omnidirectional beacon signal
Some could be lost. Reception in omni pattern
In beacon mode, the beacon signal cannot be decoded,
In the pattern, multiple beacon signals are
Need to be aware that turns can be split
And However, the probability of this collision depends on whether each wireless station 1 is transmitting.
Can be kept lower by choosing
You. For example, the basics in the wireless network system
Quasi-period time interval t i Duration t for d Window
Can be selected at random from (t
d <T i ). FIG. 7 shows the management control unit 10 of the wireless station 1 shown in FIG.
5 showing a packet transmission / reception control process executed by
It is a low chart. In FIG. 7, first, in step S1,
Variable beam antenna 101 with rotating sector pattern
Rotational scanning that changes every predetermined azimuth angle (for example, 30 degrees)
And the received signal is received.
Received signal with a signal strength level above a predetermined threshold
Is determined, and if YES, the step
On the other hand, if NO, the process proceeds to step S8. S
Whether there is a packet signal to be transmitted in step S8
Is determined, and if YES is determined, the process proceeds to step S9.
On the other hand, if NO, the process proceeds to step S1. In step S9
Is the beacon signal to be transmitted in the
It is determined whether the answer is YES and if YES, the process proceeds to step S10.
On the other hand, if NO, the process proceeds to step S11. Step S
Transmitted beacon signal with omni pattern in 10
Thereafter, the process returns to step S1. On the other hand, in step S11
Other signals to the sector pattern or adaptive control pattern.
In other words, as shown in FIG.
After transmitting with the corresponding radiation pattern,
Return to S1. In step S3, the rotating sector pattern
Is stopped and the radiation pattern of the variable beam antenna 101 is
Into a sector pattern that points to a predetermined azimuth that has stopped.
Set. Next, in step S4, the adaptive control pattern
Receive the received signal, decode the packet information and receive
The signal strength level of the signal is measured, and in step S5
It is determined whether or not the received signal is a beacon signal.
If the answer is NO, the process proceeds to step S6.
Go to 7. In step S6, the radio in the packet information
Based on station ID, detected azimuth and signal strength level
After updating the contents of the AS table, return to step S1
You. On the other hand, in step S7, reception processing of other signals is performed.
After performing the process, the process returns to step S1. In the control flow of FIG.
In 1 and S2, the variable beam antenna 101 is rotated
The received signal with a signal strength level above a predetermined threshold
Is received, the received signal is detected.
The invention is not limited to this.
Rotationally scans through 0 degrees and signals above a predetermined threshold
Signal strength level received signal and the largest of them
The received signal may be a detected received signal. As described above, M according to the present embodiment
According to the AC protocol, as shown in FIG.
TS packet signal is converted into two consecutive RTS packet signals
By changing to a four-way hand for data communication.
Realize MAC protocol integrated as shake
Wear. As described above, the AS table proposed in the present embodiment
Adaptive MAC protocols that use
Low overhead and no interference
In addition, each radio station must maintain the indoor and outdoor angle information.
To achieve. This angle information is used for directivity and adaptive control type
In addition to the start of communication by the
(Space Division Multiple Access) Protocol
It is also necessary for effective routing of files. Ma
Signal information is also used for link state routing.
Can be Embodiments The present inventors have developed a MAC program according to a second conventional example.
Between the protocol and the MAC protocol according to the present embodiment
The following simulation was performed to compare the performance.
Was. Specifically, the SINR table according to the second conventional example
To compare with the AS table according to the present embodiment
In both tables, the packet from each wireless station 1 is
Transmission does not collide, setup signal, RQ signal, RTS
Signal, CTS signal, DATA signal and ACK signal
Assume that the cut lengths are the same. Radius R [m]
Each radio station 1 having a service area has a moving speed V = 2R,
R, R / 2, R / 4 [m / sec], and 1
Two adjacent radio stations at the center of the beam at a distance of R / 2 [m]
Positioned, the effective angle width of the sector pattern is 60 degrees
, For example, the wireless station A replaces the wireless station B with six 60
に One of the sector patterns
Therefore, in order to track, the SINR according to the second conventional example
Table or the AS table according to the present embodiment
Assume a data update interval of (3R / 8) / V [seconds]
Can be. 8 and 9 show one packet signal
About 220 microseconds (based on IEEE 802.11b).
(3R / 8) / V [seconds]
SINR table according to the second conventional example between intervals
And of each wireless station 1 according to the AS table according to the present embodiment.
The occupancy time and the occupancy ratio are shown. overhead
As for the reduction of the signal, due to the removal of the RE packet signal,
The AS table is particularly effective when the number of adjacent wireless stations is 12.
It is obvious. AS table according to the present embodiment
Overhead is the SINR table according to the second conventional example.
14.9% (number of adjacent wireless stations: 4) and 1
0.0% (the number of adjacent wireless stations: 12)
The occupancy ratio of the S table is during all table update intervals.
Is always less than 15%. As explained above, this implementation
According to the MAC protocol according to the embodiment, the second conventional example
Overhead can be significantly reduced. As described in detail above, according to the present invention, multiple
Number of wireless stations and perform packet communication between each wireless station.
Communication method for wireless network or wireless network
In the system, each of the above radio stations is an omnidirectional omni
Pattern and sector pattern with predetermined azimuth angle width
And rotation to scan while rotating the above sector pattern
Of the radiation pattern using at least the sector pattern
Equipped with a variable beam antenna that performs control,
Omni pattern is used for each wireless station in the service area
To send a beacon signal including the own station ID by broadcast
The beacon signal using the rotating sector pattern
And the azimuth and signal strength level of the beacon signal
And the plurality of wireless stations by detecting the wireless station ID.
Azimuth for each wireless station in the service area
Azimuth and signal strength level table with signal strength level
And store the packet signal in the destination wireless station.
When transmitting, the azimuth and signal strength level table
Of the azimuth of the destination station indicated by the
Turn to send a packet signal to the destination wireless station.
By transmitting, the packet signal is routed.
You. Therefore, it is hardly affected by interference signals from other stations.
Wireless communication in the correct direction without
Overhead can be greatly reduced as compared with the conventional case. Ma
Without using another system such as a GPS system.
Using the azimuth angle and signal strength level table,
Identify wireless stations and establish wireless communication links efficiently
You.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows a plurality of wireless stations 1-1 to 1--1 constituting an ad hoc wireless network according to an embodiment of the present invention.
9 is a plan layout view of FIG. FIG. 2 is a block diagram showing an internal configuration of each wireless station 1 in FIG. FIG. 3 is a diagram showing a format of packet data used in the ad hoc wireless network of FIG. 1; FIG. 4 is a table showing an example of an azimuth angle and a signal strength level table (AS table) stored in a database memory 154 of FIG. 2; FIG. 5 is a timing chart showing types of radiation patterns and wireless communication protocols at each wireless station used in the ad hoc wireless network of FIG. 1; FIG. 6 is a timing chart showing an operation of a beacon signal used in the ad hoc wireless network of FIG. FIG. 7 is a flowchart illustrating a packet transmission / reception control process executed by the management control unit 105 of the wireless station 1 in FIG. 2; FIG. 8 is a table showing simulation results of the second conventional example and the embodiment, and showing occupation times related to table updates. FIG. 9 is a table showing a simulation result of the second conventional example and the embodiment, and showing an occupancy ratio during a table update period with respect to a moving speed of a wireless station. FIG. 10 is a plan view showing an arrangement of radio stations for explaining a problem in the second conventional example. [Description of Signs] 1,1-1 to 1-9: radio station, 101: variable beam antenna, 102: circulator, 103: radiation pattern control unit, 104: packet transmission / reception unit, 105: traffic monitor unit, 106: line Control unit 107: upper layer processing device 130: packet receiving unit 131: high frequency receiver 132: demodulator 133: receiving buffer memory 140: packet transmitting unit 141: transmission timing control unit 142: transmission buffer Memory 143 Modulator 144 High frequency transmitter 151 Management control unit 152 Search engine 153 Update engine 154 Database memory 160 Spread code generator

   ────────────────────────────────────────────────── ─── Continuation of front page    (72) Inventor Kazuo Hasuike             2-2 Koikodai, Seika-cho, Soraku-gun, Kyoto 2             International Telecommunications Research Institute, Inc. F term (reference) 5K030 GA01 GA12 GA19 HA08 HD03                       HD06 JL01 JT09 LB05 MA04                       MD09                 5K033 AA02 AA04 AA05 CC01 DA05                       DA17 DB18                 5K067 AA03 BB21 CC08 DD17 DD24                       EE02 EE06 EE25 HH23 JJ74                       KK02                 5K072 AA04 BB13 BB25 BB27 DD11                       EE04 FF12 GG02 GG05

Claims (1)

  1. Claims 1. A communication method for a wireless network including a plurality of wireless stations and performing packet communication between the wireless stations, wherein each of the wireless stations includes an omni-directional omni pattern; A variable beam antenna that controls a radiation pattern using at least a sector pattern having a predetermined azimuth angle width and a rotating sector pattern that scans while rotating the sector pattern, wherein each radio in a service area of its own station is provided. Transmitting a beacon signal including its own station ID to a station by broadcast using an omni pattern; receiving the beacon signal using a rotating sector pattern; azimuth, signal strength level, and radio station of the beacon signal; By detecting the ID, a method for each wireless station in the service area of the plurality of wireless stations is performed. Storing the angle and the signal strength level in the storage device as an azimuth and signal strength level table; and transmitting the packet signal to the destination wireless station when the packet signal is transmitted to the destination wireless station. Routing the packet signal by transmitting the packet signal to the destination wireless station using the azimuth sector pattern. 2. The communication method for a wireless network according to claim 1, wherein the wireless data communication is performed between a source wireless station and a destination wireless station by an RTS / CTS access control method. The source radio station transmits an RTS signal to the destination radio station using a sector pattern directed to the destination radio station indicated by the azimuth and signal strength level table, and the destination radio station performs the rotation. RTS using sector pattern
    When a signal is received and the wireless station ID in the RTS signal is detected, the beam is directed to the source wireless station indicated by the azimuth angle and the signal strength level table based on the wireless station ID of the source wireless station. After changing to the sector pattern and receiving the RTS signal, the CTS signal is transmitted to the source wireless station using the sector pattern, and the source wireless station receives the CTS signal using the sector pattern to obtain the destination. A communication method for a wireless network, comprising: establishing a wireless link with a wireless station; and thereafter, both the source wireless station and the destination wireless station transmit and receive a data signal and an ACK signal using the sector pattern. . 3. The communication method for a wireless network according to claim 1, wherein the wireless data communication is performed between a source wireless station and a destination wireless station by an RTS / CTS access control method. In addition, each of the above radio stations further performs a radiation pattern control of the variable beam antenna with an adaptive control pattern using a predetermined adaptive control method, and the transmission source radio station indicates the azimuth angle and the signal strength level table. And transmitting an RTS signal to the destination wireless station using a sector pattern that directs a beam to the destination wireless station.
    When a signal is received and the wireless station ID in the RTS signal is detected, the beam is directed to the source wireless station indicated by the azimuth angle and the signal strength level table based on the wireless station ID of the source wireless station. After changing to the adaptive control pattern via the sector pattern and receiving the RTS signal,
    By transmitting a CTS signal to the source wireless station using the adaptive control pattern, the source wireless station receives the CTS signal by changing the sector pattern to the adaptive control pattern,
    Establishing a radio link with the destination radio station, wherein both the source radio station and the destination radio station transmit and receive data signals and ACK signals using the adaptive control pattern. Communication method. 4. A wireless network system comprising a plurality of wireless stations and performing packet communication between the wireless stations, wherein each of the wireless stations includes an omni-directional omni pattern and a sector pattern having a predetermined azimuth angle width. A variable beam antenna that controls a radiation pattern using at least a rotating sector pattern that scans while rotating the sector pattern, and broadcasts using an omni pattern to each wireless station in its service area. Transmitting means for transmitting a beacon signal including the own station ID; receiving the beacon signal using a rotating sector pattern; detecting an azimuth angle, a signal strength level, and a wireless station ID of the beacon signal; The azimuth and signal strength level for each radio station within the service area Receiving means for storing the signal strength level table in the storage device; and, when transmitting the packet signal to the destination wireless station, using the azimuth and the sector pattern of the azimuth of the destination wireless station indicated by the signal strength level table. Routing means for routing the packet signal by transmitting the packet signal to the destination wireless station.
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