JPH08162977A - Data communication equipment, data communication system and method therefor - Google Patents

Abstract

PURPOSE: To obtain data communication equipment and data communication system which are capable of performing error corrections when data communication is performed and selecting the correction coding systems according to transmission quality, and do not generates the delay of transmission speed, in the data communication equipment and the data communication system for which a PHS communication system is utilized. CONSTITUTION: In the radio section quality detection part 23 of a mobile station 2 and the radio section quality detection part 33 of a base station 3, the error ratio of the radio section is detected and the transmission quality of the radio section is detected. In error correction coding/decoding parts 21 and 31, the correction coding system according to the error ratio is selected from plurally provided correction coding systems and the correction coding is performed in accordance with the correction coding system. On the transmission side of communication data, the selected correction coding system is transmitted with communication data and the system is made to be contributed to the decoding on a reception side.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data communication device, and more particularly to a data communication device for performing data communication in the PHS communication system.

[0002]

2. Description of the Related Art Conventionally, in wireless communication of a mobile phone or the like, data communication for transmitting and receiving data is performed as well as a telephone call. Here, as a configuration for performing data communication using a mobile communication terminal such as a mobile phone, as shown in FIG. 3, the mobile station has a mobile station 6 such as a mobile phone and a facsimile function. A terminal adapter 5 is connected between the data terminals 1, and on the base station side, a base station 7 is connected to an exchange control station 8 connected to an ISDN line 4 such as an ISDN line network.
Is configured to be connected.

In the above structure, communication data sent from the data terminal 1 is wirelessly transmitted from the mobile station 6 via the terminal adapter 5 and the transmitted communication data is transmitted via the base station 7 and the exchange control station 8. Sent to the ISDN line 4. When receiving communication data from the ISDN line 4, on the contrary, the data is wirelessly transmitted from the base station 7 via the exchange control station 8 and received by the mobile station 6 via the terminal adapter 5. It is output to the terminal 1.

Here, in the wireless section between the mobile station 6 and the base station 7, an error correction technique is indispensable in order to ensure a certain level of data transmission quality and correctly transmit communication data. . In the case of the conventional configuration described above, when the wireless communication between the mobile station 6 and the base station 7 is digital wireless communication, error correction is performed between the terminal adapter 5 on the mobile station 6 side and the exchange control station 8. In addition, when the wireless communication between the mobile station 6 and the base station 7 is analog wireless communication, it is performed between the data terminal 1 and the terminal as a communication partner connected to the ISDN line 4. .

The error correction method is also determined to be a predetermined method, and the determined error correction is performed regardless of the transmission quality. In addition, as a conventional data receiving device,
As shown in the data receiving apparatus of JP-A-2-97142, data such as whether the number of correction bits exceeds a preset reference point, whether error correction is performed, or whether error correction is possible There is a method in which the quality of the reception state is determined based on the above, and the determination result is displayed on the display device.

On the other hand, as a second generation cordless telephone,
The development of a personal handy phone system (PHS) is in progress, but this PHS is a digital communication system that enables household cordless terminals to be used outdoors. According to this PHS, high-speed mobile communication is possible. However, the call charge is low, the base station is small and inexpensive, the terminal is also small, and by installing the base station in an underground mall, etc., it is possible to call even in areas where conventional mobile phones cannot be used. Many effects such as being possible are expected.

[0007]

However, in the PHS communication system, if data communication is performed by a system similar to the conventional data communication system using mobile communication, such as a terminal adapter or a switching control station. A separate device must be provided, and an error correction method must be determined in advance between the terminal adapter and the exchange control station, or the data terminal and the partner terminal must have a special error correction function. Furthermore, when a predetermined error correction function is provided to perform a certain error correction coding regardless of the transmission quality, even if the transmission quality is good, the data to be sent will be a code with a large redundancy and the transmission speed will be high. Has the problem of being slow.

Further, according to the data receiving apparatus of Japanese Patent Laid-Open No. 2-97142, although the quality of the receiving state is displayed on the display device, the correction coding method cannot be selected depending on the quality of the receiving state. Therefore, the present invention is a data communication device and a data communication system, which can perform error correction when performing data communication, and need to provide another device such as a terminal adapter or a switching control station as described above. , There is no need for a data terminal or the like to have a special error correction function, and a correction coding method can be selected according to the transmission quality, so that there is no delay in the transmission rate and a data communication system. It is intended to provide.

[0009]

The present invention was created to solve the above problems, and, firstly, a data communication method of a data communication device for performing data communication via a wireless section. In, the transmission quality of the wireless section is detected by the wireless section quality detecting means (23, 33), and the correction code is detected according to the transmission quality of the wireless section detected by the wireless section quality detecting means (23, 33). The encoding method selecting means (21, 31) is characterized in that, if the transmission quality in this wireless section is poor, it selects a correction encoding method having a high correction capability from a plurality of correction encoding methods.

A second aspect of the present invention is a data communication method of a data communication device for performing data communication via a wireless section, wherein the transmission quality in the wireless section at the time of data communication from the data transmitting side to the data receiving side. Is detected by the wireless section quality detecting means (23, 33) on the data receiving side, and the transmission quality of the wireless section detected by the wireless section quality detecting means (23, 33) on the data receiving side is transmitted to the data transmitting side. Then, the correction coding method selection means (21, 3) on the data transmission side
1) is characterized in that if the transmission quality in this wireless section is poor, a correction coding system having a high correction capability is selected from a plurality of correction coding systems.

Thirdly, in the first or second configuration, the data communication is a communication system based on the PHS standard, and the wireless section quality detecting means (23, 3).
According to 3), the quality detection of the wireless section is judged by the CRC error detection bit of the PHS standard, and the PHS standard information channel is selected by the correction coding system selecting means (21, 31). The data inside is encoded.

A data communication device and a data communication system based on the present invention were created in order to solve the above problems. Fourthly, a data communication device for performing data communication through a wireless section. Therefore, wireless section quality detecting means (23, 33) for detecting the transmission quality of the wireless section
And a correction coding method selecting means (21, 31) for selecting a correction coding method from a plurality of correction coding methods according to the detection result of the wireless section quality detecting means (23, 33).
And are included.

Fifth, in the above-mentioned first configuration, the data communication apparatus further transmits the correction coding scheme selected by the correction coding scheme selecting means (21, 31) to the receiving side. Coding method transmission means (21, 3)
It is characterized by having 1). Also, the sixth
In the fourth or fifth configuration, the data communication device performs data communication by the PHS communication method, and the wireless section quality detection means (23, 33) has a CRC.
The error detection is performed by the method described above, and the data of the information channel in the communication physical slot is corrected and coded.

Seventh, there is provided a data communication system having a plurality of data communication devices and performing data communication via a wireless section, wherein each of the plurality of data communication devices transmits in the wireless section. A correction coding method is selected from a plurality of correction coding methods according to the detection results of the wireless section quality detecting means (23, 33) for detecting the quality and the wireless section quality detecting means (23, 33). And a correction coding method selection means (21, 31).

Eighth, in the seventh configuration, each of the plurality of data communication devices further receives the correction coding system selected by the correction coding system selecting means (21, 31) on the receiving side. It is characterized by having a correction coding method transmitting means (21, 31) for transmitting to. Ninth, in the seventh or eighth configuration, at least one of the plurality of data communication devices is a mobile station to which a data terminal is connected, and at least one other is a base station. It is characterized in that data communication is performed between the station and the base station.

Tenth, in the seventh or eighth configuration, at least two of the plurality of data communication devices are mobile stations to which data terminals are connected, and data communication is performed between the two mobile stations. It is characterized by performing.
Further, eleventhly, in the configuration according to any one of the seventh to tenth aspects, while the data communication device performs data communication by the PHS communication method, the wireless section quality detecting means (23, 33) causes an error due to CRC. It is characterized in that the detection is performed and the data of the information channel in the communication physical slot is correction-encoded.

[0017]

In the data communication method of the first structure according to the present invention, an appropriate correction coding method is selected according to the transmission quality of the wireless section detected by the wireless section quality detecting means (23, 33). In the data communication method of the second configuration according to the present invention, the wireless section quality detecting means (23, 3) on the data receiving side is provided.
The correction coding method on the transmission side is selected according to the transmission quality of the wireless section detected by 3).

In the data communication method of the third structure according to the present invention, the quality is detected by the CRC error detection bit of the PHS communication system (RCR standard 28), and the error correction is performed on the data in the information channel. In the data communication device and the data communication system of the fourth and seventh configurations of the present invention, the wireless section quality detecting means (23, 3).
3) detects the transmission quality in the wireless section. Then, the correction coding method selection means (21, 31) selects the wireless section quality detection means (23, 3) from the plurality of correction coding methods.
A correction coding method is selected based on the transmission quality detected in 3), and the communication data is correction-coded by the selected correction coding method and sent to the receiving side.

In this configuration, since data communication is performed by correction coding, even when used in the PHS communication system, it is possible to improve the quality of transmission in data communication. Further, in the PHS communication system, if the data communication device of the present invention is provided in the mobile station or the base station, it is not necessary to provide another device such as a terminal adapter or a switching control station, and the data terminal or the like has a special error. It is not necessary to have a correction function. Further, since the correction coding method is selected from among a plurality of correction coding methods according to the transmission quality, the transmission speed is not delayed even when the transmission quality is good.

In the data communication device and the data communication system having the fifth and eighth configurations, the correction coding system transmitting means (21, 31) transmits the selected correction coding system. At the data receiving side, the original data is decoded by the decoding method suitable for the coding method selected at the sending side, and when sending the data to the sending side, the data is sent by the transmitted corrective coding method. Just communicate.

In the data communication device and the data communication system having the sixth and eleventh configurations, the data communication is performed by the PHS communication method, and the wireless section quality detecting means (23, 33) also has an error due to the CRC. Detect. Further, in the correction coding, the data of the information channel in the communication physical slot is correction-coded.
According to the data communication system having the ninth configuration,
Since at least one of the plurality of data communication devices is a mobile station and at least one of them is a base station, data communication between the mobile station and the base station becomes possible. Furthermore, the first
According to the data communication system having the configuration of 0, since at least two of the plurality of data communication devices are mobile stations, the mobile station can perform data communication.

[0022]

Embodiments of the present invention will be described with reference to the drawings.
As shown in FIG. 1, the data communication system A1 in the present embodiment has a mobile station 2 and a base station 3 as data communication devices.
The mobile station 2 is compliant with the PHS communication system and functions as a cordless telephone at home and as a mobile telephone outdoors. A data communication terminal for communicating data such as a personal computer and a FAX is connected to the mobile station 2. Further, the base station 3 is provided in each place outdoors and in the parent device at home, and is connected to the ISDN line 4 as a public line network.

Here, the structure of the mobile station 2 will be described. As shown in FIG. 1, the mobile station 2 includes an error correction coding / decoding unit 21, a radio communication control unit 22, and a radio section quality detection unit 23. Have Here, the wireless section quality detecting unit 23 as the wireless section quality detecting means detects the transmission quality of the wireless section from the error rate of the received data received from the base station 3 side, and specifically, CRC error detection is performed on the CRC-encoded (cyclic-encoded) received data.

Further, the error correction code / decoding unit 21 as the correction coding system selecting means and the correction coding system transmitting means.
Is connected to the data terminal 1, the wireless communication control unit 22, and the wireless section quality detection unit 23, selects an error correction coding method according to the transmission quality information of the wireless section from the wireless section quality detection unit 23, and Error correction coding is performed according to the selected error correction coding method. Further, the error correction code / decoding unit 21 determines the coding method in the received error correction code, transmits the coding method to the receiving base station, and receives the error correction code received from the base station 3. It has a function to decrypt the original data. Further, in the PHS communication system, CRC is used for error detection encoding on the transmission side, and this error detection encoding is also performed in this error correction encoding / decoding unit 21.

The radio communication control unit 22 is in charge of radio communication with the base station 3 and outputs the error-correction-coded data to the PH.
Modulation is performed by a modulation method that conforms to the S communication method, and conversely, reception data that is modulated by that modulation method is demodulated.
The wireless communication controller 22 is connected to the antenna 24. Next, the configuration of the base station 3 will be described. As shown in FIG. 1, as in the case of the mobile station 2, the error correction code / decoding as the correction coding system selecting means and the correction coding system transmitting means. A unit 31, a wireless communication control unit 32,
Wireless section quality detection unit 33 as wireless section quality detecting means
And an antenna 34, and the configuration of each of the above-mentioned units is similar to that of the mobile station 2. The error correction code / decoding unit 31 is connected to the ISDN line 4.

A data communication system A1 based on the above configuration
The operation of will be described. A case where data communication is performed from the mobile station 2 to the base station 3 side will be described. First, the mobile station 2 selects an optimum correction coding method according to the transmission quality in the wireless section, and performs correction coding according to that method. The selection of the optimum correction coding method will be described later.

Specifically, some data for detecting the error rate in the wireless section is received from the base station 3 side, the mobile station 2 detects the transmission quality in the wireless section based on the data, and the optimum correction coding method is used. Select. That is, the optimum correction coding method is selected by detecting the error rate in the wireless section. That is, in the PHS communication method, all data transmitted in the wireless section is transmitted to the receiving side after being encoded by the transmitting side for CRC error detection, and the receiving side performs error detection to perform communication. Since it is determined whether or not there is an error in the data slot, the mobile station 2 causes the wireless section quality detection unit 23 to perform error detection based on the communication data obtained from the base station 3. In the communication physical slot of the PHS communication system shown in FIG. 4, CRC is applied to 196 bits from the channel type to the error detection check bit.

Radio section quality detection unit 23 in mobile station 2
Performs CRC error detection and calculates the error rate in the wireless section by various methods. That is, a method of calculating a change in the frequency of occurrence of an error, a method of calculating an error rate by a change in the number of bits in which the error is corrected when the receiving side corrects the error-correction-coded data. Calculate the error rate by. When the error rate is calculated, information about the error rate is sent to the error correction coding / decoding unit 21, and the optimum correction coding method is selected according to the transmission quality of the wireless section.

When the optimum correction coding system is selected, the error correction coding / decoding unit 21 performs the correction coding by that system, and the corrected coded data is suitable for the PHS communication system in the radio communication control unit 22. After being modulated by the modulation method, it is transmitted to the base station 3 side. The correction code received by the base station 3 is demodulated by the radio communication control unit 32 and then decoded by the error correction code / decoding unit 31 by a decoding method according to the coding method selected by the mobile station 2. And is transmitted to the partner terminal via the ISDN line 4. It should be noted that which correction coding method has been selected in the mobile station 2 is transmitted to the base station 3 side, and the method of transmission will be described later.

Next, a method of selecting the optimum coding method and a method of transmitting the selected coding method to the receiving side will be described. In the present embodiment, four levels of A method to D method are set according to the transmission quality of the wireless section, and the encoding method selected as the transmission quality deteriorates is changed sequentially from the A method to the D method. Go. The A method to the D method will be described. In the A method, as shown in FIG.
While data transmission is performed as it is, in the B method, the bit value is repeated three times for encoding. further,
In the C method, the bit value is repeated 5 times, and in the D method, the bit value is repeated 7 times. In other words, from method A to D
The number of bit repetitions is increased as the system is approached. For example, if the data from the data terminal is "010110"
If it is “001”, in system A, “01011”
0001 ”remains the same, but in the B method,“ 000111000111111000000000 ”
Repeat 111 times, such as "111".

Here, as shown in FIG. 2, the 160-bit information channel in the slot is divided into a coding method transmission section and a data transmission section, and the above-mentioned correction coded data is stored in the data transmission section. Assigned. On the other hand, which of the four coding methods has been selected is transmitted to the receiving side by the information of the coding method transmitting unit. That is, when the coding method transmission unit is "00", the A method, when "01" is the B method, when "10" is the C method, and when it is "11", the D method and 2 bits The information is determined in advance on the base station 3 side and the mobile station 2 side. Since there should be no error in the information on this coding method, the D method used when the transmission quality is the worst is adopted, and the bit value is set to 7
The coding method transmission section is repeatedly transmitted as 14-bit data.

As described above, by adopting the method of repeating the bit value, it is possible to correct the error from the A system to the D system. That is, for example, in the case of the B system, even if an error occurs in the wireless section and "000" becomes "010", "1" in "010" can be corrected as "0". That is, in the B method, an error of up to 1 bit can be corrected. Similarly, in the C method, the bit value is repeated 5 times, so that an error of up to 2 bits can be corrected, and in the D method, the bit value is repeated 7 times, so that the error of up to 3 bits can be corrected. Can be corrected. The method A cannot correct the error.

In the above description, the mobile station 2
Is the base station 3 for transmitting data for error rate detection in the wireless section.
It has been described that the mobile station 2 detects the transmission quality in the wireless section and selects the optimum correction coding method from the mobile station 2 side, but the mobile station 2 sends data for error rate detection to the base station 3 side. Alternatively, the base station 3 side may detect the transmission quality, select the optimum coding method, and transmit it to the mobile station 2 side. In addition, in the above, as a method of correction coding, 4
Although the method of dividing into stages is shown, the number of stages is arbitrary as long as it is a method of dividing into a plurality of stages. Further, in the above description, the error detection is performed in the initial operation of the data transmission, but the transmission quality may change during the data transmission. Therefore, the transmission quality should be detected regularly. Is desirable.

The mobile station 2 side receives the error-encoded data for detecting the transmission quality from the base station 3 side when the wireless section quality detecting section 23 detects the transmission quality. In the case of the two-way communication performed by the conversation method, the error detection may be performed based on the communication data received from the base station 3. Further, in the case of one-way communication such as facsimile communication, the base station 3 side is requested to transmit data for error detection in advance, and the error detection is performed based on the data. Alternatively, the transmission quality may be detected on the base station 3 side and sent to the mobile station 2 side.

Next, a case where data communication is performed from the base station 3 side to the mobile station 2 side will be described. Also in this case, as in the case of the above-described embodiment, the transmission quality is detected on the base station 3 side, the optimum coding method is selected, and data communication is performed by that method. In the above embodiment, the case where the data communication is performed between the mobile station 2 and the base station 3 has been described, but the present invention can be applied to the data communication between the mobile stations as shown in FIG. . That is, in FIG. 5, in the data communication system A2, the mobile station 2 has the same structure as in FIG.
With the configuration having the error correction code / decoding unit 21, the wireless communication control unit 22, and the wireless section quality detection unit 23 as shown in FIG. It is possible to improve the quality of transmission.

Further, as the above error correction coding system,
As described above, it is not limited to repeating the bit value,
A cyclic code such as a BCH code or a Reed-Solomon code, a convolutional code, or the like may be applied. In the above embodiment,
The case of adopting the PHS communication system has been described, but the PHS communication system is not limited as long as the correction coding system is selected according to the transmission quality.

[0037]

According to the data communication method of the first aspect of the present invention, the error correction method is selected according to the quality of the wireless section. That is, the higher the error correction capability is, the more bits are added / increased due to the error correction function, and the original data transmission speed is reduced. Therefore, the correction coding method is selected from a plurality of correction coding methods according to the transmission quality. Therefore, data can be transmitted quickly and reliably.

According to the data communication method of the second aspect of the present invention, the quality of the wireless section is detected on the receiving side. That is,
The quality of the wireless section may differ depending on the direction of the data communication (mobile station 2 to base station 3 or base station 3 to mobile station 2). Therefore, the receiving side detects the quality, and the correction coding method on the transmitting side is selected according to the detected quality. Therefore, the correction coding method can be selected more accurately.

According to the data communication method of claim 3 of the present invention, the communication method is based on the PHS standard (Standard-28), and the quality detection of the wireless section is judged by a CRC error detection bit, and the correction is performed. According to the correction coding system selected by the coding system selecting means (21, 31),
Only the data in the information channel is encoded. Therefore, no new configuration is added for quality detection. Further, since only the data in the information channel is encoded, it does not deviate from the PHS standard.

According to the data communication device of claims 4 to 6 and the data communication system of claims 7 to 11 based on the present invention, since the data communication is performed by the correction coding, it is possible to improve the quality of the transmission in the data communication. Can be done, P
Even when used in the HS communication system, it is possible to improve the quality of transmission. Further, if the mobile station or the base station is provided with the data communication device of the present invention, it is not necessary to provide another device such as a terminal adapter or a switching control station,
It is not necessary for the data terminal or the like to have a special error correction function. Further, since the correction coding method is selected from among a plurality of correction coding methods according to the transmission quality, the transmission speed is not delayed even when the transmission quality is good.

Further, in particular, according to the data communication apparatus of claim 5 and the data communication system of claim 8, since the correction coding method transmitting means is provided, the data receiving side has the coding method selected by the transmitting side. The original data can be decoded by a decoding method suitable for the above, and when the data is transmitted to the transmitting side, the data communication can be performed by the transmitted correction coding method.

Further, in particular, according to the data communication system of claim 9, data communication between the mobile station and the base station is possible, and according to the data communication system of claim 10, a plurality of data communication devices are provided. Since at least two of them are mobile stations, data communication can be performed by the mobile stations.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a data communication system according to the present invention and a data communication device in the data communication system.

FIG. 2 is an explanatory diagram showing bit coding of an error correction code in the correction coding system of the data communication device according to the present invention.

FIG. 3 is a block diagram showing a configuration of a data communication system when a conventional mobile phone is used.

FIG. 4 is an explanatory diagram showing a configuration of a communication physical slot in the PHS communication system.

FIG. 5 is a data communication system according to the present invention,
It is a block diagram which shows the communication system between mobile stations.

[Explanation of symbols]

 A1, A2 data communication system, 1 data terminal, 2 mobile station, 3 base station, 4 ISDN line, 21 error correction code / decoding unit, 22 wireless communication control unit, 23 wireless section quality detection unit, 24 antenna, 31 error correction Encoding / decoding unit, 32 wireless communication control unit, 33 wireless section quality detection unit, 34 antenna.

Claims (11)

[Claims] 1. A data communication method for a data communication device for performing data communication via a wireless section, wherein the transmission quality of the wireless section is detected by a wireless section quality detecting means (2).
3, 33), and the correction coding method selection means (21, 31) detects the wireless section quality according to the transmission quality of the wireless section detected by the wireless section quality detection means (23, 33). A data communication method for a data communication device, wherein a correction coding system having a high correction capability is selected from a plurality of correction coding systems if the transmission quality is poor. 2. A data communication method for a data communication device that performs data communication via a wireless section, wherein the transmission quality in the wireless section at the time of data communication from the data transmitting side to the data receiving side is the wireless section of the data receiving side. The quality is detected by the quality detecting means (23, 33), and the wireless section quality detecting means (23, 3) on the data receiving side is detected.
The transmission quality of the wireless section detected by 3) is transmitted to the data transmitting side, and the correction coding system selecting means (21, 31) on the data transmitting side is transmitted.
However, if the transmission quality in this wireless section is poor, a correction coding system having a high correction capability is selected from a plurality of correction coding systems, and the data communication method of the data communication device is characterized. 3. The data communication is a communication system based on the PHS standard, and the wireless section quality detecting means (23,
33), the quality of the wireless section is detected by the CRC error detection bit of the PHS standard, and the PHS standard information channel is selected by the correction coding system selecting means (21, 31). 3. The data communication method for a data communication device according to claim 1, wherein the data in the data is encoded. 4. A data communication device for performing data communication via a wireless section, the wireless section quality detecting means (23, 33) for detecting transmission quality of the wireless section, and the wireless section quality detecting means (23). , 33), and a correction coding method selecting means (21, 31) for selecting a correction coding method from a plurality of correction coding methods according to the detection result. 5. The data communication device further comprises a correction coding method transmitting means (21, 31) for transmitting the correction coding method selected by the correction coding method selecting means (21, 31) to the receiving side. The data communication device according to claim 4, wherein 6. The data communication device performs data communication by the PHS communication method, the wireless section quality detecting means (23, 33) performs error detection by CRC, and further, the data of the information channel in the communication physical slot. 6. The data communication device according to claim 4, wherein the data is corrected and encoded. 7. A data communication system having a plurality of data communication devices and performing data communication via a wireless section, wherein each of the plurality of data communication devices detects a transmission quality of the wireless section. Section quality detection means (23, 3
3) and a correction coding method selecting means (21, 3) for selecting a correction coding method from a plurality of correction coding methods according to the detection result of the wireless section quality detecting means (23, 33).
1) A data communication system comprising: 8. The correction coding method transmitting means (21, 21) for transmitting the correction coding method selected by the correction coding method selecting means (21, 31) to the receiving side by each of the plurality of data communication devices. 31) The data communication system according to claim 7, further comprising: 9. At least one of the plurality of data communication devices is a mobile station to which a data terminal is connected, and at least one other is a base station, and data communication is performed between the mobile station and the base station. The data communication system according to claim 7, which is characterized in that. 10. At least two of the plurality of data communication devices.
9. The data communication system according to claim 7, wherein one is a mobile station to which a data terminal is connected, and data communication is performed between two mobile stations. 11. The data communication device performs data communication by the PHS communication method, the wireless section quality detecting means (23, 33) performs error detection by CRC, and further, the data of the information channel in the communication physical slot. Is corrected and encoded.
A data communication system according to any one of 1.