JPH08223644A - Mobile data communication system - Google Patents

Abstract

PURPOSE: To provide high-speed and stable communication system for mobile data communication. CONSTITUTION: When digital radio communication is performed between a base station (b) and a mobile station (a) and data are communicated between a data terminal 18 connected through a digital transmission line network 12 to the base station (b) and a data terminal 14 connected to the mobile station (a), signal speed in a radio zone and signal speed specified on a digital transmission line are converted at the mobile station (a) and the base station (b). When originating a call from the mobile station (a), processing is switched to a speed converting circuit 15 for data communication by the mobile station (a) and that signal format information is transferred to the base station (b). Based on this information, the base station (b) switches processing to a speed converting circuit 16 for data communication and transfers that signal format information to a host station. When originating a call from the host station, the host station transfers data and that signal format information to the base station (b) and the base station (b) switches processing to the speed converting circuit 16 for data communication and transfers that signal format information to the mobile station (a). Based on that information, the mobile station (a) switches processing to the speed converting circuit 15 for data communication.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a system for transmitting and receiving high speed and economical digital signals in a mobile radio communication line.

[0002]

2. Description of the Related Art Conventionally, even when digital radio communication is realized between a mobile station and a base station, an analog modem is installed in each of the mobile station and a host station which is a communication partner, and both The transmission line between them was used as an analog transmission line. That is, as shown in FIG. 8, after converting the digital signal from the data terminal device in the mobile station into the analog signal of the voice band by the modem, it is sent to the host station via the wireless section and the transmission path, and again by the modem of the host station. After converting to a digital signal, the data was sent to the data terminal device on the other side to realize communication.

[0003]

Therefore, it is difficult to stably perform high-speed data communication due to the restriction that the wireless base station and the host station perform analog modem communication via a wired transmission line. In addition, there is a drawback that it takes a long time to connect because it goes through an analog network. SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned conventional drawbacks and to provide a communication system capable of stably performing high-speed data communication and having a small connection delay.

[0004]

In order to solve such a problem, the present invention is a system for performing digital radio communication between a base station and a mobile station, which is provided from the base station via a digital transmission line network. In the mobile data communication system in which the data terminal device connected to the mobile station and the data terminal device connected to the mobile station perform data communication, the signal speed of the wireless section and the signal specified by the digital transmission line in the mobile station and the base station. Convert with speed. The present invention realizes high-speed data communication by converting a signal from a data terminal device into a signal speed defined by a digital transmission line by performing speed conversion in two steps between a mobile station and a base station and connecting the signals. To do.

According to the present invention, when the mobile station and the host station perform data communication by calling from the mobile station, the mobile station switches from the codec for voice signal to the speed conversion circuit for data communication, and The signal format information is transferred from the mobile station to the base station, and at the base station, the codec for voice signal is switched to the speed conversion circuit for data communication based on this information, and the signal format information is passed through the digital transmission path. Transfer to the host station.

When the host station and the mobile station perform data communication by calling from the host station, the host station transfers the data and its signal format information to the base station via the digital transmission line, At the base station, the codec for voice signal is switched to the speed conversion circuit for data communication, and the signal format information is transferred to the mobile station. At the mobile station, the codec for voice signal is used for data communication based on this information. Switch to speed conversion circuit.

In the present invention, error control is not performed between the mobile station and the base station with respect to a signal error occurring in the wireless section between the mobile station and the base station, and the data terminal device of the mobile station operates. It is desirable to detect a signal error between the running program and the program running on the data terminal device of the host station to perform error control. Further, in the mobile station, it is desirable to install a codec for voice signals, a switching circuit for the speed conversion circuit for data communication, and a speed conversion circuit in the mobile phone. Further, in the mobile station, the switching circuit for the codec for voice signal and the speed conversion circuit for data communication may be built in the mobile phone, and the speed conversion circuit for data communication may be built in the expansion slot of the personal computer.

[0008]

According to the present invention, when performing data communication, in the mobile station, the codec for voice signal is switched to the speed conversion circuit, and the signal of the data terminal device is converted to the signal of the wireless section,
In the base station, the codec for voice signal is switched to the speed conversion circuit, the signal in the wireless section is converted into the signal in the digital transmission line, and the line control station is connected to the data terminal device via the digital transmission line. Therefore, by slightly modifying the mobile station and the base station designed for voice communication, a highly reliable data communication system can be realized.

[0009]

FIG. 1 is a diagram showing an embodiment of the present invention. First, the case of performing voice communication will be described. When performing voice communication, the signal from the handset 1 of the mobile station a is converted into a digital signal by the codec 2, and the switching circuit 3 causes the radio 4 to operate.
Sent to The radio signal is modulated by the radio device 4 and transmitted from the antenna 5 to the base station b.

The radio wave received by the antenna 6 of the base station b is demodulated by the radio 7 into a digital signal. This digital signal is sent from the switching circuit 8 to the codec 9, is converted into a digital signal by the codec 9, is converted into an ISDN signal by the line control station 11 via the switching circuit 10, and a transmission capability to the effect that it is a voice signal is added. Then, the telephone is connected to the digital telephone 13 via the ISDN network 12 to make a voice call.
It should be noted that voice in the opposite direction can be transferred by a route opposite to the above to make a voice call.

Next, the case of performing data communication will be described. When performing data communication, the digital signal from the data terminal device 14 of the mobile station is sent as a serial signal to the speed conversion circuit 15. The speed conversion circuit 15 converts the signal speed into a wireless section signal speed, and the signal speed is sent to the wireless device 4 via the switching circuit 3. The radio signal is modulated by the radio device 4 and transmitted from the antenna 5 to the base station b.

The radio wave received by the antenna 6 of the base station b is demodulated into a digital signal by the radio device 7. This digital signal is sent from the switching circuit 8 to the speed conversion circuit 16, is converted into an ISDN signal speed by the speed conversion circuit 16, and is then converted into an ISDN signal by the line control station 11 via the switching circuit 10 and the ISDN network. Connected to the terminal adapter 17 via 12. The digital signal output from the terminal adapter 17 is transferred to the data terminal device 18. The digital signal in the reverse direction is transferred through the route reverse to the above, and data communication can be performed.

In this embodiment of the present invention, high-quality communication can be realized by using the ISDN network which is a digital transmission line, and the host side can use a commercially available terminal adapter. It has the advantage that high-speed data communication can be performed with only a slight modification to the designed wireless communication equipment.

Next, the case of making a call from the mobile station side of the embodiment of FIG. 1 will be described in more detail with reference to the flowchart of FIG. First, the case of performing voice communication from a mobile station will be described. At 101, it is determined whether or not the data communication is performed, and when it is the voice communication, at 102, the switching circuit 3 (FIG. 1) is switched to the audio side A side. Next, at 103, the transmission capability is set to "voice" and this information is transferred to the base station. Next, at 104, the operation of the codec 2 is started.

On the other hand, when the base station receives the transfer capability from the mobile station, it judges the content at 105, and when it is voice communication,
At 106, the switching circuit 8 is switched to the A side, and at 107, the transfer capability transferred from the mobile station is transferred to the line control station as "voice". Next, at 108, the operation of the codec 9 is started. The line control station transfers the transfer capability transferred from the base station to the ISDN network as "voice" at 109. The ISDN network performs connection operation as voice communication.

Next, a case where data communication is performed from the mobile station will be described. At 101, it is determined whether or not the data communication is performed, and when it is the data communication, the switching circuit 3 is switched at 110 to the data communication side B side. Then the transmission capability is "unlimited digital" with 111.
The lower layer compatibility information element is, for example, "V110, 19.2kb
Set to "ps" and transfer this information to the base station. Next 112
Starts the operation of the speed conversion circuit 15 (when the speed of the wireless section is 32 kbps and the speed of the data terminal device is 19.2 kbps, the speed conversion circuit 17 starts from 19.2 kbps according to the conversion rule of V110.
Convert speed to 32kbps).

On the other hand, when the base station receives the information such as the transmission capability from the mobile station, the content is judged at 105, and when it is detected that it is "unlimited digital" or "V110, 19.2 kbps", the switching circuit at 113 8 and 10 are switched to the B side, the transmission capability transferred from the mobile station at 114 is set to "unlimited digital",
Transfer the lower layer compatibility information element to the circuit control station as "V110, 19.2 kbps". Next, the operation of the speed conversion circuit 16 is started at 115 (the speed of the wireless section is 32 kbps, the ISD
Since the signal speed of N is 64 kbps, the speed conversion circuit 25 uses I4
The speed conversion from 32kbps to 64kbps by the 60 conversion rule).

The line control station sets 109 the transfer capability transferred from the base station to "unrestricted digital", and transfers the lower layer compatibility information element to "V110, 19.2 kbps" to the ISDN network. The ISDN network performs connection operation as digital communication.

Next, the procedure for switching between voice and data communication will be described. In the mobile station, the control unit 19 controls the switching circuit 3
To the wireless section and information to that effect is added to the wireless section. In the base station, the control unit 20 extracts the information from the radio signal and instructs the switching circuits 8 and 10 to switch the information, and sends the information to that effect to the line control station 11.

Here, the transmission capability means 64 kbps required by the transmitting terminal device for the digital communication network (ISDN network).
This is a parameter that represents the transmission capacity of the intra-network line for voice transmission, 64 kbps unrestricted digital transmission, etc., and JT-Q931 "ISD
N user / network interface layer 3 overview ”. Also, what is low layer consistency?
It is a parameter for describing the terminal function in detail corresponding to the first to third layers of the OS17 layer model, and JT-Q939 "ISDN
Typical DSS for telecommunication services
1 Service identification coding ”.

Next, the case of making a call from the terminal device side of the communication network of the embodiment of FIG. 1 will be described in more detail with reference to the flowchart of FIG. First, a case where voice communication is performed from the terminal device will be described. At 201, the circuit control station transfers information such as transmission capability and low layer compatibility included in the incoming signal from the ISDN network to the base station. When the base station determines in 202 that it is voice communication based on the content of the information, it switches in 203 to the switching circuit 8
Switch 10 and 10 to the A side. Next, at 204, the information is transferred to the mobile station. Next, at 205, the operation of the codec 9 is started.

On the other hand, the mobile station judges the transfer capability at 206, and when it detects that it is a voice signal, the switching circuit 3 at 207.
To the A side. Next, at 208, the operation of the codec 2 is started.

Next, data communication (V110, 1
9.2kbps) will be explained. At 201, the circuit control station transfers information such as transmission capability and low layer compatibility included in the incoming signal from the ISDN network to the base station. 202 base stations
When it is judged from the contents of the information that the communication is data communication, the switching circuits 8 and 10 are switched to the B side at 209. Then 21
0 to transfer information to mobile station. Next, at 211, speed conversion circuit
16 operations start (the speed of the wireless section is 32kbps,
Since the signal speed of ISDN is 64kbps, speed conversion circuit
25 is the I460 conversion rule from 32kbps to 64kbps speed conversion).

On the other hand, when the mobile station judges at 206 the transmission capability from the base station and detects that it is data communication,
At 212, the switching circuit 3 is switched to the B side. Next, the operation of the speed conversion circuit 15 is started at 213 (when the speed of the wireless section is 32 kbps and the speed of the data terminal device is 19.2 kbps, the speed conversion circuit 17 changes the speed from 19.2 kbps to 32 kbps according to the V110 conversion rule. Convert).

Next, the procedure for switching between voice and data communication will be described. In the base station, the control unit 20 instructs the switching circuits 8 and 10 to perform switching based on the control information from the line control station 11, and adds information to that effect to the wireless section.
In the mobile station, the control unit 19 extracts the information from the radio signal and instructs the switching circuit 3 to switch.

Although only 19.2 kbps has been described as the communication speed, 300, 600, 1200, 2400, 4800,
Synchronous and asynchronous communication at 9600bps etc. are possible. Also, if it is limited to asynchronous communication, by not transmitting start bit and stop bit in the wireless section,
Communication at 38.4kbps is possible.

FIG. 4 shows an outline (a) of a block for relaying a signal between the data terminal device of the mobile station and the data terminal device of the host station, and the respective functions (b) are shown in the upper stage thereof.
Indicates. Next, the functional structure of the communication program between the data terminal device of the mobile station and the data terminal device of the host station will be described with reference to FIG.

The data terminal equipment of the mobile station is roughly classified into a physical layer 301, a lower layer 302 having an error control function, and a higher layer 303 for performing high function processing. Similarly, the data terminal device of the host station is roughly classified into a physical layer 304, a lower layer 305 having an error control function, and a higher layer 306 performing high-performance processing. Physical layer 30
1 and 304 make a physical connection with the serial terminal, and transfer the signal from the lower layer to the speed conversion circuit 15 in the mobile station and the terminal adapter 17 in the host station, and at the same time in the reverse direction, that is, from the serial terminal. It has a function of transferring the signal of (1) to the lower layer.

The lower layers 302 and 305 have a function of detecting an error in signal transmission / reception with a lower layer of a communication partner and performing retransmission control and the like, thereby realizing high quality communication. Specifically, it receives a signal from the physical layer, decodes the error control signal contained therein, sends the signal without the control signal to the higher layer when there is no error, and sends it to the physical layer when there is an error. Send a resend request signal. Also, when a retransmission request signal from the physical layer is received, the signal is retransmitted to the physical layer. On the other hand, it has a function of adding a signal for error control to the signals from the higher layers 303 and 306 and transferring them to the physical layer.

The higher layers 303 and 306 have a function of receiving signals from lower layers, displaying information to the user, and transferring keyboard information from the user to the lower layers. Data communication is realized between the mobile station and the host station by the functions of the high, middle, and low layers as described above, but in this embodiment, the signals generated in the wireless line between the mobile station and the base station are The mistake is
The error control function of the lower layer of the communication program of the data terminal device between the mobile station and the host station is processing.

In the system of FIG. 4, a normal wired LA is used without adding a signal error control function in the wireless communication line.
A program having an error control function for N, for example, TCP / IP (Transmission Control Protocol / Internet) in the lower layer.
SLIP (IP over Sirial)
SLIP or PPP and TCP by using a protocol called Line) or PPP (Point-to-Point Protocol)
The signal error control realized by and can be used, and high-level programs such as telnet that can be used on TCP / IP used in ordinary Ethernet can be used to facilitate high-quality communication. It has the advantage of being realizable.

In this embodiment, the line control station is supposed to have a function of centrally controlling a plurality of base stations, but it goes without saying that the present invention can be implemented without this line control station. .

Next, the case of performing asynchronous 38.4 kbps mobile data communication will be described with reference to FIG. 64 kb signal for data terminal equipment of 600 bps to 19.2 kbps used in ISDN
To convert to ps, the two-step speed conversion method is adopted.
After converting the signal of 0bps to 19.2kbps to the intermediate speed of 32kbps by the V110 conversion rule, it is converted to 64kbps by the I460 conversion rule. However, with this method, if the intermediate speed is 32 kbps, 19.2 kbps
I could only transmit. This embodiment is an example of performing asynchronous 38.4 kbps mobile data communication when the intermediate speed of the transmission path in the wireless section is 32 kbps.

A signal (asynchronous 38.4 kbps) from the data terminal device of the mobile station is processed by the speed conversion circuit 15 (FIG. 1) to remove the start bit and the stop bit from the data bit (8
A signal for synchronization is added to (bit) and transmitted as a 32 kbps signal. At this time, since 38.4 kbps x 8/10 = 30.72 kbps, the remaining 1.28 kbps synchronization signal can be added to the 32 kbps transmission line. In other words, 1.28
Since kbps is 1.28 ÷ 32 = 0.04, a 4-bit synchronizing signal can be added to 96 bits of data.

Referring to FIG. 5, (a) is a case where a 4-bit synchronization signal is added to the above 96 bits of data, and in addition to that, 2 bits are added to 48 bits of data as shown in (b).
When adding a bit synchronizing signal, a case where a 1-bit synchronizing signal is added to 24 bits of data as shown in (c) may be considered.

In the base station, the received signal (32 kbps) is converted to 64 kbps by the speed conversion circuit 16 according to the V110 conversion rule and transferred to the line control station 11. By doing so, asynchronous 38.4 kbps transmission can be performed using the 32 kbps transmission path. Also, with the same conversion method, 1
9.2 kbps transmission, 8 kbps transmission line for 9.6 kbps transmission, 4 kbps transmission line for 4.8 kbps transmission, 2 kbps transmission line for 2.4 kbps transmission, 1 kbps transmission line for 1.2 kbps transmission, 600 kbps transmission can be performed on each 500 bps transmission line.

Next, another configuration example of the mobile station will be described with reference to FIG. In FIG. 6, the handset 1 is connected to the mobile unit 401,
Codec 2, switching circuit 3, radio 4, antenna 5,
A speed conversion circuit 15 and a control unit 19 are provided. Mobile 40
1 and the data terminal device 14 are connected via a speed conversion circuit 15. If an RS232C-compliant serial signal is used for the interface between them, the versatility will be great. By doing so, a general-purpose device such as a personal computer can be used as the data terminal device.

Next, another configuration example of the mobile station will be described with reference to FIG. In FIG. 7, the mobile device 402 includes a handset 1, a codec 2, a switching circuit 3, a wireless device 4, an antenna 5, and a control unit 19. The data terminal device 14 has a speed conversion circuit 15 built in an expansion slot. This expansion slot is used for a modem for a personal computer or PCMCIA (Personal Computer Memory Car).
Slots standardized by the d International Association) can be used. By doing so, a general-purpose personal computer can be used for implementing the present invention, and the mobile device can be made compact.

[0039]

As described above, according to the present invention, the following excellent effects are obtained. (1) Since communication is performed via the ISDN network, high-speed digital communication can be stably performed, and a system with less control delay can be provided. (2) The mobile station, the base station and the line control station designed for voice communication can be slightly modified to realize a high-speed digital communication network without any changes on the ISDN network and the host side. (3) When accessing the LAN, error control can be performed using the communication protocol developed for LAN, so highly reliable communication is realized without performing error control in the wireless section. In addition, it is possible to easily access the Internet via the LAN.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention.

FIG. 2 is a flowchart showing a procedure for making a call from the mobile station side in the embodiment of FIG.

FIG. 3 is a flowchart showing a procedure for making a call from the terminal device side of the communication network in the embodiment of FIG.

FIG. 4 is a diagram illustrating a functional structure of a communication program between a data terminal device of a mobile station and a data terminal device of a host station.

FIG. 5 is a diagram illustrating a bit configuration of a signal.

FIG. 6 is a block diagram showing another configuration example of a mobile station.

FIG. 7 is a block diagram showing still another configuration example of the mobile station.

FIG. 8 is a diagram illustrating a conventional mobile communication system.

[Explanation of symbols]

 a mobile station b base station 1 handset 2, 9 cordic 3, 8, 10 switching circuit 4, 7 radio 5, 6 antenna 11 line control station 12 ISDN network 13 digital telephone 14, 18 data terminal device 15, 16 speed conversion Circuit 17 Terminal adapter 19, 20 Control unit 401, 402 Mobile unit

Claims (6)

[Claims] 1. A digital radio communication is performed between a base station and a mobile station, and data is transmitted between a data terminal device connected from the base station via a digital transmission line network and a data terminal device connected to the mobile station. A mobile data communication method for performing communication, wherein the mobile station and the base station convert the signal speed in the wireless section and the signal speed specified by the digital transmission path. 2. When the mobile station and the host station perform data communication by a call from the mobile station, the mobile station switches from a codec for voice signal to a speed conversion circuit for data communication, and signal format information thereof. From the mobile station to the base station, and the base station switches from the codec for voice signal to the speed conversion circuit for data communication based on this information, and the signal format information is transmitted to the host station via the digital transmission line. The mobile data communication system according to claim 1, wherein the mobile data communication system is transferred to the mobile data communication system. 3. When the host station and the mobile station perform data communication by a call from the host station, the host station transfers the data and its signal format information to the base station via a digital transmission line, At the base station, the codec for voice signal is switched to the speed conversion circuit for data communication, and the signal format information is transferred to the mobile station. At the mobile station, the codec for voice signal is used for data communication based on this information. The mobile data communication system according to claim 1, wherein the mobile data communication system is switched to a speed conversion circuit. 4. An error control is not performed between the mobile station and the base station for a signal error occurring in a wireless section between the mobile station and the base station, and the data terminal device of the mobile station operates. 2. The mobile data communication system according to claim 1, wherein an error control is performed by detecting a signal error between the program and the program operating in the data terminal device of the host station. 5. The mobile data according to claim 1, wherein in the mobile station, a codec for voice signals and a switching circuit of a speed conversion circuit for data communication and a speed conversion circuit are installed in a mobile phone. Communication method. 6. In a mobile station, a codec for voice signals and a switching circuit for a speed conversion circuit for data communication are built in a mobile phone, and a speed conversion circuit for data communication is built in an expansion slot of a personal computer. The mobile data communication system according to claim 1, wherein: