JPS59103442A - Radio communication control system - Google Patents

Abstract

PURPOSE:To neglect a received notice command when there is any error and to fetch it as an effective command when no error exists, by transmitting continuously the notice command from the transmission side for plural number of times and checking the error of the received notice command at the receiving side. CONSTITUTION:A command having the same frame format as the HDLC procedure is transmitted from the transmission station for plural number of times. That is, an attribute notice command representing the picture element density, the paper size and a compressing system or the like is provided in an information section of the frame and this is transmitted continuously from a command generating section 24 for plural number of times. The receiving station checkes errors of the received command at a command analysis section 25, and if there is any error, the said command is neglected and when >=1 command without error exists, it is fetched as the effective command. After the effective command is received, the 1st page of the picture information is received and when it is finished and the next page exists from the transmission station, a continuous transmission notice command is transmitted continuously for plural number of times, and when the effective command of the said command exists in the receiving station, the 2nd page of the picture information is received. Similarly, this operation is continued until the communication end notice command is received.

Description

DETAILED DESCRIPTION OF THE INVENTION (1) Technical field of the invention The invention relates to a communication control system in a wireless data communication system. The method according to the invention is used, for example, to control transmission between a computing device and a terminal device or between a facsimile device.

(2) Background of the technology Wireless data communication is widely used in all fields of society, such as between computing devices and input/output terminal devices, and facsimile communication, mainly in the police, fire departments, disaster prevention, and mass media. This is done between devices. In these wireless data communications, multiple receivers can receive the same data at the same time by tuning the receiver's channel to a predetermined frequency band.
Although it is possible to perform "simultaneous broadcasting" and has wide-area coverage, problems inherent to wireless transmission include deterioration in the quality of received image information due to fading, noise, multipath echo, etc., and improvements have been desired.

(3) Prior art and problems Information processing devices usually use a control method in which the receiving station returns a response to notify the presence or absence of an error (or its details) in response to a command from the transmitting station. In addition, the transmitting station performs recovery processing (command retry) if the response from the receiving station is not received within a certain period of time, or if an error is notified in the response from the receiving station.
etc. are being processed. However, when using a control system that returns responses in the same way as with wired communication during wireless relay communication, there is a problem in that the responses from each receiving device overlap and cause interference, making it impossible to continue the sequence. Conventionally, 62 methods have been used to deal with such interference in responses during simultaneous broadcasts. That is, ■,
All receiving stations do not return a response.C) Among the receiving stations,
Only one (representative station) returns a response, and the other receiving stations do not. With method (2), there is a problem that even if an error occurs, there is no response from the receiving station, so command retries from the transmitting station cannot be expected. In addition, in method (2), the station with the worst reception condition is selected from among the receiving stations that are the target of the broadcast as the receiving station that returns the response.In other words, the transmitting station Since recovery processing is performed based on the response, it is necessary to select the station that most requires recovery processing (the station with the worst reception condition) as the representative station, and therefore the sending station needs to manage the other party. There was a problem. Furthermore, considering the case where the simultaneous target stations differ depending on the content of the message, the receiving station needs to be equipped with both a control section that does not return a response and a control section that does return a response, resulting in a problem that the scale of the device becomes large. In addition, in method (■), if a command is received normally at the representative station, but an error is detected at a receiving station other than the representative station, recovery processing from the transmitting station cannot be expected, and reliability cannot be said to be sufficient. There wasn't.

(4) Purpose of the Invention In view of the above-mentioned problems, the invention provides high reliability to received image information in wireless data communication without returning a response from the receiving device to a command from the transmitting device during broadcast communication. The purpose of the present invention is to provide a wireless communication control method that is also versatile.

(5) Structure of the Invention According to the present invention, data communication between information processing devices such as a computing device, an input/output terminal device, and a facsimile device is performed via wireless, and in response to commands from a sending side. In a data communication system that uses a communication format in which the receiving side does not respond, the sending side continuously sends notification commands such as redundant numbers and attributes for PB detection, continuous transmission, and communication termination, etc., and the receiving side The received command is checked for errors, and if there is an error, the command is ignored, and if there is only one command without an error, the command is taken as a valid command, and the same command without an error is received. This is achieved by providing a wireless communication control method characterized in that, if there are several commands, only one of them is accepted as a valid command.

(6) Embodiments of the Invention FIG. 1 is a diagram schematically showing a form of data communication using wireless. In FIG. 1, data from an information processing device such as a computing device provided in a transmitting station 10 is transmitted wirelessly and received at the same time by a plurality of receiving stations located at appropriate locations. Facsimile communication is an example in which such a communication form is often used, and in this case, a facsimile machine having built-in devices corresponding to transmitting and receiving stations is used.

FIG. 2 is a block diagram showing a device that performs a wireless communication method applied to a facsimile machine as an embodiment of the present invention. In FIG. 2, on the transmission side in the upper stage, there is a mechanism section 21 consisting of a paper feeding mechanism, an optical system, etc., a reading section 22 consisting of a scanner for scanning, and a reading section 22 consisting of a scanner for scanning. A compression section 23 that performs band compression, and a command generation section 24 that generates a plurality of commands used as a communication control method according to the present invention are provided. On the other hand, on the receiving side, there is a command analysis unit 25 that checks errors among the received commands and analyzes valid commands, a message source unit 26 that restores the original data based on the valid commands,
A recording control section 27 that controls recording, and a mechanism section 28 that includes a paper feeding mechanism, a printing mechanism, etc. are provided. Furthermore, the facsimile machine has a main control unit 2 which manages the sequence and transmits commands from the command generation unit 24 according to the sequence, and also receives the commands according to the sequence in the case of reception and instructs the command analysis unit 25.
01, a line control unit 202 that checks the line status according to the sequence and controls the line transmission speed, the normal transmission speed is 300 bit/B, for example, and the image transmission speed (D
a modem unit 2o3 that performs switching between 9600 bit/s and 9600 bit/s;
A wireless control unit 204, an antenna 205, and the like, which are composed of a transmitter/receiver and the like for use as a wireless facsimile, are also provided.

FIG. 3 is an operational sequence diagram of the apparatus shown in FIG. 2. Third
In the figure, from the transmitting station side, the frame format is HD.
A command having a format similar to the LC procedure is sent multiple times. That is, the frame is composed of a flag sequence, an address part, a control part, an information part, a frame inspection sequence for error detection, etc., and an attribute notification command indicating pixel density, paper size, compression method, etc. is provided in the information part. Is this ffi? The command generator 24 continuously transmits the command N number of times. On the receiving station side, the command analysis unit 25 checks the received command for errors, and if there is an error, the command is ignored, and if there is only one command without an error, that command is determined to be a valid command, If there are multiple identical commands without errors, only one of them will be used as a valid command. After receiving the valid command, the first page of the image information is received, and when the reception of that page is completed, if there is a next base from the transmitting station, the continuous transmission notification command is continuously transmitted multiple times to the receiving station. When a valid command is received at the command number, the second page of image information is received. When the final page is completed in this way, the transmitting station continuously transmits communication end notification commands, and when the receiving station receives a valid command as described above, the reception ends. In this case, image information can be recognized by the human eye even if there is some noise, and since image information requires a large amount of data, sending multiple pieces of information will result in a very long communication time. I decided not to send it multiple times.

Regarding the function on the receiving side, the same function is required even in the conventional method (2) described above (IJ at the receiving station other than the representative station). functions), so there is no increase in the amount of circuitry compared to the conventional method. Also, the overall communication time is not so long compared to the case of returning a response.

(Advantageous Effects of the Invention) As explained in detail above, the wireless communication control system according to the present invention can provide a highly reliable and versatile data communication system.

[Brief explanation of the drawing]

FIG. 1 is a diagram schematically showing a wireless data communication system, and FIG. 2 is a block diagram showing a device that performs a wireless communication method applied to a facsimile machine as an embodiment of the invention. , and FIG. 3 are operation sequence diagrams of the apparatus shown in FIG. 2. (Explanation of symbols) 10...Transmitting station, 11-1n...Receiving station, 21°2
8... Mechanism section, 22... Reading section, 23... Compression section, 24... Command generation section, 25... Command analysis section, 26... Restoration section, 27... Metering section Control unit, 201
...Main control section, 202...Line control section, 203...
- Modulation/demodulation section, 204... Radio control section, 205... Antenna, 206... Mechanism control section. Patent Applicant Fujitsu Limited Patent Application Agent Patent Attorney Akira Aoki Patent Attorney Kazuyuki Nishidate Patent Attorney Yukio Yamaguchi Patent Attorney 1 Figure 2 30 256-

Claims (1)

[Claims] 1. Data communication between information processing devices such as computing devices, input/output terminal devices, facsimile devices, etc. is carried out via wireless, and the receiving side uses a communication form that allows the receiving side to respond to commands from the sending side. In a data communication system, the sending side continuously sends notification commands such as redundant tags and attributes for error detection, continuous transmission, and end of communication multiple times, and the receiving side checks the received commands for errors. If there is an error, the command is ignored, and the correct command is 1
If there is only one command, the command is taken as a valid command, and if there are multiple identical commands without errors or errors, only one of them is taken as a valid command.