JP2000040996A - Wireless communication system - Google Patents

Abstract

(57) Abstract: A wireless communication system capable of suppressing a decrease in throughput caused by error detection using CRC as a wireless data communication protocol. A wireless communication device having a master function of a PHS is provided with a frame processing unit, a synchronization processing unit, a retransmission unit, an error detection and correction function unit, and the like according to a PHS data communication protocol. Then, when the data error rate in the radio section deteriorates, the 32-bit CRC part of the conventional frame is replaced with error correction parity data to improve the apparent data error rate (frame retransmission rate).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention comprises a radio communication device connected to a public line and having a complex function such as ISDN data communication, PHS radio master station, facsimile, etc., and a radio slave station capable of radio data communication. Wireless communication system.

[0002]

2. Description of the Related Art In recent years, with the rapid spread of pan-con communication represented by the Internet, digital public networks have once again attracted attention. Also, according to ISDN-TA
(Terminal Adapter) products are starting to appear on the market, and the need for high-speed data communication is growing.

[0003] In the case of data communication using a terminal adapter or the like, a data terminal is connected to the terminal adapter using a cable such as RS232C, and 2400, 4800, 9600, 1600 are connected to the terminal adapter from the data terminal.
Data is transmitted at a transmission speed of 9.2K, 38.4K (bps) or the like.

In a terminal adapter receiving data,
V. CCITT standard recommendation. 64 data according to 110
The transmission rate is converted to Kbps and transmitted to ISDN.

[0005] The terminal adapter is a public line I
Since the SDN is connected, a telephone, a facsimile or the like used for other media (voice, image) communication is generally used by connecting to the analog port of the terminal adapter.

However, since such a conventional terminal adapter can be connected to a data terminal only by a wired cable, the data terminal and the terminal adapter need to be installed close to each other. In addition, when the place where the terminal adapter is connected to the public line and the place where the data terminal is installed are far apart, long-distance wiring is required, and wiring work is required.

Therefore, it has been proposed to use a digital wireless technology, which has become very popular in recent years, so that the data terminal can be connected to a public communication line even when the data terminal is not connected to a terminal adapter by a wired cable.

For example, a PHS which has recently attracted particular attention among digital radio communication systems is a digital radio having a transmission speed of 32 Kbps per communication slot, and therefore has a high interference removal capability and excellent confidentiality. Also known as In Japan, a frequency band of 1.9 GHz is allocated to PHS, and the frequency is spreading.

At present, this PHS service uses voice (telephone).
In response to the demand for data services, related organizations proceeded with standardization work.
In January, the standards of the air section were revised at the standards meeting of the Association of Radio Industries and Businesses (ARIB), and in April 1996, the Telecommunications Technical Committee (TTC) revised the standards to the network part.・ Additional work was performed.

[0010] Furthermore, the "PHS Internet Access Forum" established in October 1996,
We are studying an end-to-end transmission control procedure with a focus on error control when accessing the Internet using PHS and transmitting various data. Currently, "PIAF
An industry standard (draft) will be proposed as "S" (PHS Internet Access Forum Standard), and after conducting mutual experiments, it will be made an industry standard.

[0011] By these, 32Kb using PHS
Data communication of ps can be realized. Hereinafter, an outline of wireless data communication in a conventional wireless communication system will be described.

FIG. 2 is a block diagram showing the configuration of this type of wireless communication system.

In FIG. 1, a wireless communication device 10 connected to a digital public communication network (hereinafter, referred to as ISDN) 106 is shown.
1, a PHS telephone 102 and a PHS slave unit 104 are wirelessly connected, and a PC 103 is connected by a wired cable. A data terminal 105 is connected to the PHS slave unit 104.

FIG. 21 is an explanatory diagram showing a sequence of control commands exchanged among the radio communication device 101, the PHS slave unit 104, and the data terminal 105.

This is an example of a case where the data terminal 105 and the PHS slave unit 104 are connected by wire, and data communication is performed with the partner ISDN terminal via the wireless communication device 101 according to the PHS data communication protocol.

First, when the communication application of the computer of the data terminal 105 starts the data transmission operation,
A data communication request (801) is sent to the PHS slave unit 104.

The PHS slave unit 104, which has received the data communication request (801), sets up the wireless communication device 10 in order to secure a wireless channel for setting up a call with the wireless communication device 101.
1, a link channel establishment request (802) is sent.

Upon receiving the link channel establishment request (802) from the PHS slave unit 104, the wireless communication apparatus 101 checks the communication source such as the wireless channel idle status and the ISDN line idle status, and checks the PHS slave unit 104 (Step 803).

The PHS slave unit 104 to which the channel has been assigned by the wireless communication apparatus 101 permits the data terminal 108 to start communication, and upon receiving the destination information (805) of the destination from the data terminal 105, sets the call (806). ) Start the process.

The wireless communication apparatus 101 includes a PHS slave unit 10
When the call setting (806) is received from No. 4, the call setting process for ISDN is started, and a call setting acceptance (808) is transmitted to the PHS slave unit 104. Further, upon receiving the call setting acceptance (809) from the ISDN, and further receiving the call signal (817) and the response signal (820), it notifies the PHS slave unit 104 of the contents.

The PHS slave unit 104 stores the definition information (81
0, 811), function information (812, 813), secret key information (814), authentication information (815, 816), etc., and when a call signal (818) and a response signal (821) are received, the data terminal 103, the content is notified, and data communication is started.

In this manner, PHS data can be transmitted / received to / from a partner connected via ISDN, so that a data link is established with the partner through a predetermined negotiation according to the PHS data communication protocol. Then, transmission / reception of data is started.

When the above data transmission process is repeated and a disconnection request (824) is received from the data terminal 105, the PHS
The slave unit 104 releases the data link, and further transmits a disconnection signal (825).

The disconnection signal (82) is sent from the PHS slave unit 104.
Wireless communication apparatus 101 receiving 5) requests ISDN to disconnect the call (826), and transmits a release signal (827) to PHS slave unit 104. PHS slave unit 1
04, after receiving the release signal (827), notifies the data terminal 105 of the release of the call (828).

Finally, the radio communication apparatus 101 releases the radio link between the ISDN link and the PHS slave unit 104.

The present radio communication system provides a data terminal with a 32 Kbps data communication environment using the PHS data communication protocol by the above operation.

[0027]

However, in the above conventional system, the wireless communication device (PHS master) and the PH
Since wireless transmission is performed between the S slaves, data errors frequently occur depending on the environment in which the system is installed, and a transmission speed of 32 Kbps may not be provided.

That is, in the PHS data communication protocol, this data error is dealt with by retransmitting the data frame using an error detection function by CRC.
If frame retransmissions occur frequently, a decrease in throughput is inevitable.

An object of the present invention is to provide a wireless communication system capable of suppressing a decrease in throughput caused by error detection using CRC as a wireless data communication protocol.

[0030]

A first aspect of the present invention is a radio communication apparatus which can be a radio master station having a connection means for connecting to a digital public communication network, and a radio communication apparatus which is wirelessly accommodated in the radio master station. In a wireless communication system having a wireless communication device that can be a station, the wireless communication device includes a detecting unit configured to detect a data error rate in a wireless section, and a wireless communication frame of the wireless communication frame when the data error rate in the wireless section deteriorates. Retransmitting means for retransmitting the wireless communication frame by replacing the error correction data.

For example, when an error detection and correction function is installed in a wireless communication device having a master unit function of a PHS and a wireless communication device serving as a PHS slave unit, when a data error rate in a wireless section deteriorates, a conventional wireless communication device is used. 32 bits C of frame
The RC portion is replaced with error correction parity data to improve the apparent data error rate (frame retransmission rate).

[0032] In claim 2 of the present invention,
By providing means for selecting data transmitted from the data terminal and voice data transmitted from the wireless telephone, and means for transmitting the data selected by the selection means to the public communication line, the data terminal connected from the wired It is also possible to connect to a public communication line from a wirelessly connected data terminal or a wireless telephone.

In the third aspect of the present invention,
By providing means for selecting which channel of the public communication line to output the data transmitted from the data terminal and the voice data transmitted from the wireless telephone, the ISD
It is intended to enable data transmission while making a telephone call using a wireless telephone by effectively using two channels of N.

Further, in claim 4 of the present invention,
Means for storing data received from a wired data terminal in a memory, means for converting data stored in the memory into serial data in a predetermined format, and data received from a wirelessly connected data terminal. By providing a means for selecting one or two from the audio data transmitted from the wireless telephone and the serial data,
Two of the wired data terminals (such as PCs), wirelessly connected data terminals, and wireless telephones are simultaneously ISD
N.

According to a fifth aspect of the present invention,
By providing means for wirelessly connecting to a plurality of wireless telephones and means for selecting one or two from data transmitted from the data terminal and a plurality of voice data transmitted from the wireless telephone, When a wireless telephone is accommodated, two of the data terminal and the plurality of wireless telephones can be simultaneously connected to the ISDN.

In the sixth aspect of the present invention,
By providing means for performing transmission rate conversion processing, 32
The data transmitted from the wireless data terminal at 64 Kbps is 64
It enables transmission to a Kbps ISDN line.

In the seventh aspect of the present invention,
By providing means for switching the signal selection combination in the selection means according to the information element type in the line connection control message transmitted from the radiotelephone or the data terminal, optimal route selection is made for voice communication and data communication, respectively. Is made possible.

[0038] In claim 8 of the present invention,
Means for controlling so as not to perform echo cancellation processing when the communication attribute indicated in the call request message transmitted from the data terminal connected wirelessly or the wireless telephone connected to the data terminal is digital data. With this arrangement, it is possible to determine that data transmitted by a wirelessly connected data terminal is data that does not require echo cancellation processing.

In the ninth aspect of the present invention,
A digital public communication line and a digital wireless communication line are provided by providing means for generating a multiplied clock synchronized with a clock extracted from the digital public communication line and means for assembling / disassembling a time division multiplexed frame in synchronization with the generated clock. Can be operated in synchronization with each other, and occurrence of underrun and overrun of data can be prevented.

According to a tenth aspect of the present invention, a means for comparing the phases of two types of clocks, a means for filtering the comparison result, and a filtering output that is input to a voltage controlled oscillator and generated in accordance with the phase difference Means for changing the clock frequency to be generated, and means for limiting the frequency of the generated clock to a value within a predetermined range, so that even if the accuracy of the clock extracted from the digital public communication line temporarily deteriorates, the digital This makes it possible to maintain the accuracy of the clock for operating the wireless communication line within a predetermined range.

According to the eleventh aspect of the present invention, there are provided means for making and receiving a call to and from a public communication line, and means for converting a communication data sequence synchronized with the public communication line into a data sequence received using PHS radio. By providing the inverse conversion means, clock synchronization between the public line and the wireless communication line can be achieved.

According to a twelfth aspect of the present invention, there is provided a means for assembling / disassembling a communication frame for performing wireless data communication inside a wireless master station, a frame synchronization establishing means, a communication frame retransmitting means, The provision of the detection means enables wireless data communication.

According to a thirteenth aspect of the present invention, there is provided means for assembling / disassembling a communication frame for performing wireless data communication inside a wireless slave unit, frame synchronization establishing means, communication frame retransmitting means, The provision of the detection means enables wireless data communication.

According to a fourteenth aspect of the present invention, an error correction encoding / decoding means, a means for measuring the frequency of data errors, and a data error rate exceeding a predetermined value are provided in the radio base station. In this case, the use of the error correction coding and decoding means enables the wireless master station to use the error correction function during wireless data communication.

According to a fifteenth aspect of the present invention, an error correction coding / decoding means, a means for measuring the frequency of data error, and a data error rate exceeding a predetermined value are provided in the wireless slave station. In this case, the use of the error correction coding and decoding means enables a wireless slave station to use an error correction function during wireless data communication.

According to a sixteenth aspect of the present invention, there is provided means for switching whether or not to perform wireless data communication using error correction coding / decoding means for a wireless master station and a wireless slave station; Communication is error correction coding means,
In the case of wireless data communication by using the means for storing the setting of whether or not using the error correction decoding means, whether to use the error correction function, or to use the error detection and frame retransmission function, and, This state can be stored.

[0047]

DESCRIPTION OF THE PREFERRED EMBODIMENTS [First Embodiment] FIG.
FIG. 2 is a block diagram illustrating a hardware configuration of the wireless communication device 101 according to the first embodiment of the present invention. The overall configuration of the wireless communication system in which the wireless communication device 101 is provided is as follows:
For example, suppose that shown in FIG.

In the figure, a central control unit (MPU) 20
1 controls the entire apparatus 101 via a data bus and an address bus 202 using programs and data stored in a ROM 203 and a RAM 204.

Facsimile (FAX) engine unit 205
Is composed of a CPU, an image processing unit and the like, and controls facsimile operation. A CPU 206 is a CPU for a facsimile engine, and a bus 207 is a data bus of a facsimile engine unit. These are connected to devices (208 to 216) necessary for performing a facsimile operation and control them.

Further, the printer has a color printer 208, a color scanner 209, an operation panel 210, a parallel communication interface port 211, and a parallel communication interface connector 212. Data transmitted from the PC via the parallel communication interface connector 212 is transmitted to the printer 208. To print on the scanner 20
9 can be transmitted to the PC via the parallel communication interface connector 212.

Further, a facsimile modem 213, a handset 214, a speaker 215, and a hold melody generating unit 216 are controlled by the facsimile engine unit 205 and connected to an analog switch 217 to output voice or facsimile analog data. Is analog switch 2
17 is connected to a public communication line.

The shared register 218 is used when data is exchanged between a device connected to the data bus 207 of the FAX engine unit 205 and a device connected to the data bus of the MPU 201.

The serial communication controller 219,
RS232C driver / receiver 220, RS232C
It has a connector 221 which is connected to a communication port of the PC and functions as an interface for data transmitted and received by the PC to and from a public communication line.

Further, it has a modular connector 222 for connecting an ISDN (point U) and a DSU 223, and converts data exchanged with the central office exchange into a TTL level signal.

Further, there are provided a modular connector 224 (a), a transformer 224 (b), and a driver / receiver 224 (c) for bus connection with a terminal connected to the ISDN (S / T point). ISDN with function to connect to
By converting the AMI code data exchanged with the terminal and the TTL level signal, a plurality of ISDN terminals can be connected to a bus and used.

The ISDN interface unit 225
Performs control of ISDN layers 1 to 3,
It has an input / output function for ISDN B channel data. Further, the echo canceller 226 removes an echo generated in the public communication line. The echo canceler control signal 232 performs operation mode setting of the echo canceller and on / off control of the echo canceller operation.

Also, the HDLC controller 227
This is to perform assembling / disassembling processing of HDLC format data on SDN. Further, the PHS data communication controller 228 performs assembling / disassembling processing of data in the PHS data communication protocol format.

The first port switch 229 has 5
-2 changeover switch 230, and 2-1 changeover switch 231.
A process of switching data transmitted on the B1 channel and the B2 channel of the DN is performed.

Further, the second port switch 233 is
-1 switching switches 234 and 235, which perform switching processing of data connected to the port switch 229 under the control of the MPU 201. In addition, the second port switch 233 is connected to the I.O. 460 data conversion processing unit 236
And performs a transmission distance conversion process of 32 Kbps / 64 Kbps.

The PHS master unit 237 has the following configuration. The CPU 238 is a PHS control CPU
And the PHS baseband processing units 239 and 240
Voice codec unit, wireless transmission frame assembling / disassembling unit,
It is composed of a modulation / demodulation unit and the like. The high-frequency unit 241 and the antenna 242 transmit analog voice and facsimile data input / output via the analog switch 217 to a PC.
M data, and 2
Enables 32 Kbps wireless voice / data transmission of the channel.

Next, the function of each signal in the above configuration will be described.

First, the signal 243 is transmitted between the MPU 101 and the FA.
A serial communication signal for communication between CPUs of the CPU 206 of the X engine unit.
This is a serial communication signal for communication between CPUs of the CPU 206 of the master unit.

The signals 245 and 246 are analog signals for connecting the analog switch 217 and the PHS master unit 237,
9. The signal is converted into a PCM signal by the PCM codec of the PHS baseband processing unit 240.

The signal 247 is an analog signal 245
Is 64 Kbps data obtained by PCM conversion of
48 is data of 64 Kbps which communicates in the first wireless slot. The signal 249 is the analog signal 24
6 is 64 Kbps data obtained by performing PCM conversion on signal 6, and signal 250 is 64 Kbps that communicates in the second wireless slot.
Data.

The signal 251 is 32 Kbps data used in the unrestricted digital communication, and is connected to the ISDN B channel in order to connect to the ISDN B channel. It is connected to the port switch 229 via the 460 converter 236.

The signal 252 is supplied to the baseband processing section 239
Signal 253 is connected to the PCM audio data.
PCM audio data connected to the baseband processing unit 240. Also, the signals 254 and 255 correspond to the I.D. 460 is unrestricted digital data connected to the processing unit 236,
Each is connected to the switch 231 and the PHS data communication controller 228.

The signal 256 is 64 Kbps data connected to the PHS data communication controller.
57 is 64 Kbp connected to the HDLC controller
This is the data of s. The signal 258 is 64 Kbps data transmitted on the ISDN B1 channel.
59 is 64 Kb transmitted on the ISDN B2 channel.
This is ps data.

The signal 260 is an 8K signal extracted from ISDN.
Hz and 64 KHz clocks, and data lines 258,
259 are synchronized with these clocks. Signal 26
1 is 8 KHz output from the PHS master unit 237 and 3 is
2KHz and 64KHz clocks, signal 247,
248, 249 and 250 are 8KHz and 64K
Hz, and the signal 251 is 8KHz.
And 32 KHz clock.

FIG. 3 is a block diagram showing a detailed configuration of PHS base unit 237.

In the figure, switches 301 and 306
Performs switching between a signal connected to the analog switch 217, a signal transmitted wirelessly, and a signal connected to ISDN.

Analog / PCM conversion units 302 and 307
Performs conversion between an analog audio signal and a 64K PCM signal, and includes ADPCM / PCM conversion sections 303 and 30.
Numeral 8 converts between a 32K ADPCM signal and a 64K PCM signal. TDMA assembling / disassembling units 304, 3
09 is an assembly / assembly of the wireless transmission frame shown in FIG.
The π / 4 shift QPSK modulation / demodulation units 305 and 310 perform π / 4 shift QPSK modulation / demodulation as PHS wireless modems.

The multiplexer 311 selects a baseband processing unit used when performing wireless data communication. As described in the second embodiment, when PHS data communication is performed using two channels, the multiplexer is unnecessary.

In the baseband processing units 239 and 240, the switches 301 and 3 are controlled by the CPU 238.
06, and various data transmission paths are switched according to the situation.

For example, when making a call via an ISDN line using a handset, the analog switch 217 is used.
The analog signal 245 output from is analog / PC
The data is converted into a PCM code by the M conversion unit 302 and output to the data line 247.

On the other hand, when a telephone call is made between the handset and the radio telephone, the voice data converted into the PCM code is converted into the ADPCM code in the ADPCM / PCM conversion unit, and then assembled into a radio frame, and the modulated data is modulated. After that, it is transmitted to the wireless line. Further, when transmitting voice data from the wireless telephone to ISDN, data line 247 is connected to ADPCM / PCM conversion section 303.

The phase comparator 309 outputs a pulse having a width corresponding to the phase difference. 310 is a low-pass filter,
311 is a temperature compensated voltage controlled oscillator (TVCXO), 31
Reference numeral 2 denotes a frequency dividing circuit, which generates a 19.2 MHz clock 313 with a precision of ± 5 ppm synchronized with the 64 kHz clock extracted from the ISDN. The baseband processing units 239 and 240 operate based on the generated 19.2 MHz clock.

When transmitting and receiving data (including PCM-encoded voice) between the PHS and ISDN, the ISDN line and the PHS wireless line must operate in synchronization to prevent overrun and underrun of data. Is required. On the other hand, the synchronization timing accuracy of the PHS wireless line is required to be as high as ± 5 ppm.

Since the accuracy of the synchronous timing clock extracted from the ISDN is worse than ± 5 ppm, the phase comparator 309, low-pass filter 310, TV
A 64 kHz clock 260 synchronized with ISDN is generated by a PLL comprising a CXO 311 and a frequency dividing circuit 312.
There is a need to generate a 19.2 MHz clock obtained by multiplying by 1 and operate the baseband processing units 239 and 240.

The TVCXO 311 operates independently of the input voltage.
The output frequency is within 19.2 MHz ± 5 ppm, and a 64 KHz clock obtained by dividing the output clock and a 64 KHz clock synchronized with ISDN are used as the phase comparator 3.
09 is input. According to the result of the phase comparison, a 5 V pulse is output if the phase of the ISDN clock is advanced, and a 0 V pulse is output if the phase is delayed, and the signal smoothed by the low-pass filter 310 controls the TVCXO 311.

As a result, when the phase of the ISDN clock advances, the control voltage of the TVCXO 311 increases, and the TVCXO 311
11 output frequency becomes higher, TVCXO output and ISD
It goes in the direction where the phases of the N clocks match. Conversely, ISD
If the phase of the N clock is delayed, the control voltage of the TVCXO 311 decreases, the output frequency of the TVCXO 311 decreases, and the TVCXO output and the ISDN clock operate in the same direction.

FIGS. 4 and 5 are block diagrams showing a detailed configuration of the switch 230. FIG.

In the figure, a switch 230 includes decoders 401 and 402, OR gates 403 and 405, and AND
Gates 404 and 406 are provided.

FIG. 4 is a diagram showing the B1 channel and B2 channel data received from the ISDN as three signals connected to the PHS master unit 237, the HDLC controller 227, and the PLC controller 227.
A circuit for connecting to any of the HS data communication controllers 228.

The address assigned to this switch is M
When the PU 201 writes a predetermined value, the decoder 402 decodes the value and the other party to connect the data lines 258, 259 (252, 253, 254, 256, 257)
OR gate 40 connected to the other party to be connected
"L" is output to only the third OR gate, and "H" is output to the other OR gates.

Therefore, the data on the data lines 258 and 259 are transferred only from the selected OR gate to the AND gate 40.
4, and as a result, the data lines 258 and 259 are respectively connected to one of the five output data lines.

FIG. 5 shows one of the three signals, HDLC controller 227 and PHS data communication controller 228, connected to PHS master unit 237,
This is a circuit for connecting to the B1 channel and B2 channel transmission data lines.

The address assigned to this switch is M
When the PU 201 writes a predetermined value, the data line 252,
253, 254, 256, 257, data line 2
OR gate 4 to which signals connected to 58 and 259 are connected
The decoder 402 outputs L only at 05, and connects only one of the five signals to the data line 258 and the other to the data line 259.

FIG. 6 is a block diagram showing a detailed configuration of the port switch 233.

In the figure, a decoder 501 generates a signal for controlling the selection circuits 505 and 509. A serial / parallel converter 502 converts serial data received from the port switch 229 into parallel data, and extracts the serial data from the ISDN.
The parallel conversion operation is performed in synchronization with the KHz and 64 KHz clocks.

The FIFO buffer 503 buffers parallel-converted data. The parallel / serial conversion unit 504 includes a FIFO buffer 5
The PHS master unit 237 converts a parallel signal output from the P03 into serial data, and performs a conversion operation in synchronization with the 8 KHz clock and the 64 KHz clock supplied from the PHS master unit 237.

The FIFO buffer 503 prevents a data error due to a phase difference between the ISDN clock and the PHS clock. That is, the serial / parallel converter 5
02, when the output data changes, and
Even if the data latch timings of the serial conversion unit 504 match, data is buffered for 2 bytes so that no data error occurs.

The selection circuit 505 is a circuit for switching between converting serial data into an analog signal and outputting the data to a wireless line.
It is controlled by 201. The output of the main selection circuit 505 is PH
The data is input to the S master unit 237.

Conversely, data output from the PHS master unit 237 is output to the port switch 229 via the multiplexer 509, the serial / parallel converter 508, the FIFO buffer 507, and the parallel / serial converter 506.

Also, serial / parallel conversion section 510,
513, FIFO buffers 511, 514, parallel /
Regarding the serial conversion units 512 and 515,
Parallel converters 502 and 506, FIFO buffer 50
3, 507, parallel / serial conversion units 504, 508
The same operation as is performed.

However, the parallel / serial conversion unit 51
2. The serial / parallel converter 515 is 8KHz, 32
It operates at KHz clock timing, and 3
2Kbps-64Kbps speed conversion is performed.

FIG. 7 is a block diagram showing a detailed configuration of the analog switch 217.

In the figure, a register 601 is a register for controlling an analog switch, and data is written by the MPU 201 via a data bus.

The decoder 602 converts data written in the register 601 and converts the data into analog switches 603 to 61.
4 and a signal for controlling the port switches 615 and 616.

The analog switch elements 603 to 614 are
It consists of an input pin, an output pin, and a control pin. When the control pin is low, the input pin and the output pin are connected,
When the control pin is at a high level, the input pin and the output pin are disconnected.

The port switch 616 controls whether the baseband processing units 239 and 240, the melody sound 218, and the call recording output 212 in the modem are connected to the handset or the speaker.

The data sent to the baseband processing units 239 and 240 is transmitted to the modem 213 by an analog switch.
, An audio signal input from the handset 214, and the melody sound source 216 based on the control of the MPU 201. More specifically, the modem 213 is connected when performing FAX communication, the handset 214 is connected when performing a handset call, and the melody sound source 216 is connected during holding.

Conversely, during fax communication, data output from baseband processing sections 239 and 240
3 is input. Port switches 615 and 6 during a call
By switching 16, it is possible to output an audio signal output from the baseband processing unit to a handset or a speaker. During the hold, the signal output from the hold sound source 216 is connected to the handset 214 or the speaker 215, and when listening to the voice recorded in the call recording unit in the modem 212, the signal output from the modem 212 is output to the handset 214. Or a speaker 215 for use.

As described above, according to the operation mode,
A plurality of types of analog signals can be switched and input to the baseband processing unit to perform communication on an ISDN line or a wireless line.

FIG. 8 is a block diagram showing a detailed configuration of PHS slave unit 104.

[0105] In the figure, the main control unit 712 controls the main PH.
It is responsible for controlling the entire S slave unit 104.
Storage elements such as PU, R0M, and RAM are also included. The baseband processing unit 717 performs modulation and demodulation in PHS communication,
It performs time division multiplexing and converts analog signals into digital PCM or ADPCM data.

The baseband processing unit 717 includes a switch 701, an analog / PCM conversion unit 702, and an ADPC
M / PCM conversion section 703, TDMA assembly / disassembly section 704 for assembling / disassembling a wireless transmission frame, π / 4 shift Q
A PSK modulation / demodulation unit 705 is provided.

The PHS data communication processing section 718
A communication framer for performing data communication, retransmission processing, etc., an error detection unit 706 for detecting a data error in the communication frame, a frame assembling / disassembling unit for assembling / disassembling a communication frame used for PHS data communication 707,
The CPU 712 includes a buffer 708 for causing the PHS data communication processing unit 718 to perform data conversion processing. Also, a protocol control unit 709 that controls a communication protocol required for PHS data communication processing, and a retransmission processing unit 710 that performs retransmission processing of a communication frame when a data error is detected by an error detection unit 706. It has a resynchronization processing unit 711 that performs resynchronization processing when frame synchronization is lost.

The communication processing unit 713 includes the PHS slave unit 10
4 and an external data terminal. The connector 715 is for connecting an audio input / output device such as a handset or a headset. Further, the connector 716 is for connecting the PHS slave unit 104 to the data terminal.

In the baseband processing section 717, the CP
The switch 701 is switched under the control of U712, and the transmission path is switched according to the situation.

For example, when wireless communication is performed using a handset, an analog signal input from connector 715 is converted into a PCM signal by analog / PCM conversion section 702.
Is converted into a code, and is converted into an ADPCM / PCM conversion unit 703.
The signal is wirelessly transmitted from the RF unit 714 via the TDMA assembling / disassembling unit 704 and the π / 4 shift QPSK modulation / demodulation unit 705.

Next, the operation in the wireless communication system of the present embodiment as described above will be described.

Here, a case will be described in which data terminal 105 performs data communication with a partner terminal via ISDN.

In this case, since data must be transmitted to the other party in the form of PPP data, data conversion processing is required inside radio communication apparatus 101.

When data is transmitted from the data terminal 105, the communication application software of the data terminal 105 is activated, and a call request is issued to the PHS slave unit 104 connected to the data terminal 105.

[0115] Upon receiving the transmission request, PHS slave 104 transmits a signal to radio communication apparatus 101 in accordance with the sequence.

FIG. 17 is an explanatory diagram showing a sequence of control messages exchanged between the radio communication apparatus 101, the PHS slave unit 104, the data terminal 105, and the ISDN. FIG. 18 is a diagram showing an example in the sequence shown in FIG.
FIG. 9 is an explanatory diagram showing a detailed sequence of “data communication” shown in FIG.

This is an example of a case in which the data terminal 105 and the PHS slave unit 104 are connected by wire, and data communication is performed with the partner ISDN terminal via the wireless communication device 101 using the PHS data communication protocol.

FIG. 9, FIG. 10, FIG. 11, and FIG.
13, FIG. 14, FIG. 15, and FIG. 16 are flowcharts illustrating the internal processing of the PHS slave unit 104.

Radio communication apparatus 101, having received a link channel establishment request (1502) from PHS slave unit 104,
Check communication resources such as the availability of a wireless channel for a link channel and the availability of a line to a digital network (S9).
02), a link channel assignment (1503) is transmitted to the PHS slave unit 104 (S903).

Next, call setting (15)
06) (S904), the MPU 201
The transmission process of the DN interface is started (S90).
5) Rewrite the "transmission capability" information element and the "lower layer compatibility" information element written in the call setup message (S
906), start call setup to ISDN (1507) (S
907), and transmits a call setting acceptance (1508) to the PHS slave unit 104 (S908).

However, since the rewriting of the information element in step S905 involves transmitting the synchronous PPP data of 64 Kbps, the information element in the call setting message is 6
It is set to 4 Kbps unlimited digital data.

In the radio communication apparatus 101, the received PHS data communication data is
The switch 230 and the switch 231 in the port switch 229 are switched to transmit to the DN.

More specifically, the signal on data line 251 is set to I.D.
PHS via data line 255 via 460 converter 236
The switch 231 is switched to be connected to the 32 Kbps PHS data communication data interface of the data communication controller 228, and the 64 Kbps data interface of the HDLC controller 227 is connected to the data line 257 and the data line 25 via the switch 230.
8 is switched (S
910).

Further, the echo canceller 226 is set to the through mode, and I.E. The 460 conversion processing unit 236 also sets the through mode in which no conversion processing is performed (S911).

Next, the radio communication apparatus 101 sends “definition information request” (S912), “function request” (S914), “definition information request” (S917),
Upon receiving each message of “authentication request” (S920), it sends a “response” message to each message,
When the “secret key setting request” (S918) is received, a secret key setting process is performed (S919).

A call setting reception (1509) is received from the ISDN (S909), and a call signal (1517) notifying that the called user is being called and a response signal (1520) notifying the call reception of the called user are received from the ISDN. Upon receipt (S922, S1002), the contents are notified to the PHS slave unit 104 (S1001, S1003).

Next, wireless communication apparatus 101 starts data communication processing (S1004).

FIGS. 11 and 12 are detailed flowcharts of the “data communication” shown in S1004 of FIG.

The wireless communication apparatus 101 having received the negotiation frame (S1101) from the PHS slave 104 confirms the communication setting items in the communication frame, and then “responds”.
Is transmitted (S1102). Note that the PHS slave 104 uses the time interval required for transmitting and receiving the communication setting frame,
The response delay time is calculated (S1103).

A new communication frame is received from PHS slave unit 104 (S1104). If it is a control frame (S1105), its contents are confirmed. If the content is related to communication settings, the communication frame length, data compression parameter,
The PHS data communication processing unit 22
After setting to 8 (S1110), a control frame meaning "accept" is transmitted (S1111).

Thereafter, if a data frame is received from the PHS slave 104 (S1106), first, the mode flag is checked (S1114).
From the CRC information added to the last part of the frame, (S
1116), and determine whether there is a data error (S1).
118) If there is no error, transmit data is extracted from the data frame (S1120), and 32Kbps to 64K
The conversion of speed to bps. 460 part 236 (S1
121), after the HDLC controller unit 227 performs the conversion to the HDLC frame (S1122), the data is transmitted from the ISDN interface unit 225 to the ISDN (S1123).

If a data error is detected in S1118, a data frame in which a frame number requesting retransmission is set in the frame number field of the data frame is transmitted to PHS slave device 104 (S1119).

Furthermore, if the mode flag is ON in S1114, it is determined whether or not there is an error in the data from the parity information added to the last part of the frame.
If there is an error and it is uncorrectable (S
1117), execute the retransmission processing of S1119. Also,
If correction is possible in S1117, S1120
Execute the following processing.

While waiting for a data frame from the PHS slave in S1105, the "user information"
Is received (S110).
7) Rewrite the mode flag to ON (S110)
8).

The above processing is repeated, and the control frame 811 for instructing “data link release” from the PHS slave 104.
Is received (S1109), a control frame 804 for notifying “acceptance” is transmitted (S1110), and P
Upon receiving the disconnection signal (825) from the HS client 104 (S1005), the call is disconnected from the ISDN (826).
Is requested (S1006).

After transmitting the release signal (827) to the PHS slave 104 (S1007), the call to the ISDN is released (S1009).
4 is also released (S1010).

Next, in FIG. 14, when the data terminal 105 starts the data transmission operation by the application program of the data terminal 105, the PHS slave unit 104 via the data terminal connection unit 307 in FIG. A data communication request (1501) is sent to the server.

[0138] Upon receiving this data communication request, PHS slave unit 104 (S1201) requests wireless communication device 101 to establish a link channel in order to secure a wireless channel for call setup with wireless communication device 101 (S1201). 1502) is sent (S1202).

When a message indicating that the link channel has been allocated is received from wireless communication apparatus 101 (S120)
3), the PHS slave unit 104 permits the data terminal 105 to start communication (S1204), and receives the dial information (1505) of the other party from the data terminal 105 (S12).
05), call setting with the wireless communication apparatus 101 (150)
6) The process starts (S1206).

When the call setting process is completed normally and a call setting reception (1508) is received from the wireless communication device 101 (S1207), the definition information (1510) and the function information (1512) are exchanged with the wireless communication device 101. ), A secret key setting request (1514), authentication information (1515), etc. are exchanged (S1208 to S1304), and a call signal (1518) and a response signal (1521) are sent from the wireless communication apparatus 101.
Is received (S1305), the contents of the previous period are notified to the data terminal 105 (S1306), and data communication is started (S1307).

FIGS. 15 and 16 show S1307 in FIG.
6 is a detailed flowchart of “data communication” shown in FIG.

[0142] The PHS handset 104 is
Transmits a negotiation frame (801) for notifying the "protocol used" (S1401),
The wireless communication apparatus 101 waits for reception of a communication frame (802) for notifying "negotiation" to "acceptance" (S1402). The PHS slave 104 calculates the response delay time using the time interval required for transmitting and receiving the communication frame (S1403).

Next, control frames (803, 805) for notifying communication parameters and retransmission control information to wireless communication apparatus 101 are transmitted (S1404, S140).
6). Control frames (804, 806) for notifying “acceptance” for each control frame
01 (S1405, S1407), and further when transmission data is received from the data terminal 105 (S140).
8) The CPU 712 determines whether or not the mode flag is “ON” (S1409). If the mode flag is ON, the error correction processing is performed (S1410).
A CRC calculation process (S1411) is performed.

Then, the data is transferred to the frame assembling / disassembling unit 7.
07 to assemble a PHS data communication frame (S141
2) In the TDMA / TDD converter 704, the PHS
After assembling into a wireless frame (S1413), the data (807) is transmitted to the wireless communication apparatus 101 (S1).
414).

After the data transmission, if there is a request for retransmission from wireless communication apparatus 101 (S1416), retransmission processing section 710 adds 1 to the internal counter (S1416), and further checks this counter value.

If the counter value exceeds the threshold value (S1417), the control frame (814) in which the user information has been written is transmitted to the wireless communication apparatus 101 (S1417).
1419).

Then, if a control frame (815) instructing "accept user information" is received (S142)
0), the mode flag is set to “ON” (S1421).

If it is determined in S1418 that the counter value does not exceed the threshold value, the data frame corresponding to the frame number requested to be retransmitted is transmitted again (S1418).
1418).

When the data communication process is repeated and a data end notification is received from the data terminal 105 (S142)
2) A control frame (820) for instructing "data link release" is transmitted to the wireless communication apparatus 101 (S1).
425) If this is accepted (S1424),
The “data communication” process ends.

Next, the PHS slave 104 is
01 (S1308), and upon receiving a release signal from the wireless communication apparatus 101 (S1309), notifies the data terminal 105 of the release of the call (S1310).

Finally, the PHS slave 104 releases the wireless link with the wireless communication apparatus 101 (S1312), and ends the communication.

As described above, the data error rate in the PHS wireless section between the PHS master and the PHS slave increases, and
Even when frame retransmission means such as R-ARQ is used, frame retransmission frequently occurs and a decrease in throughput is inevitable. As a result, even when a transmission speed of 32 Kbps cannot be secured, a 32-bit CRC part of a communication frame is used. By replacing with parity data for error correction and correcting a data error occurring in a wireless section, a decrease in throughput can be prevented. [Second Embodiment] In the first embodiment, it is assumed that the number of wireless channels for simultaneously performing wireless data communication is one. However, by changing the configuration shown in FIG. 1, wireless data communication using two channels can be performed.

FIG. 19 is a block diagram showing a hardware configuration of the wireless communication device in this case.

Specifically, the 5-2 switch 230 is connected to the 7-
2 switch 1401, and a PHS data communication controller 1402, switch 1403, 460
This can be achieved by adding a processing unit 1404 or the like so that PHS data communication processing can be performed for each of the PHS baseband processing units 239 and 240. [Third Embodiment] In the first embodiment, PHS is used as the wireless communication system, and PHS is used as the wireless data transmission protocol.
HS data communication was assumed. However, the same effect can be obtained even when using another wireless communication system or wireless data transmission protocol. [Fourth Embodiment] In the above-described embodiment, only the case where one of the channels that can be used in the PHS communication or the ISDN communication is used has been described.
However, it is also possible to perform communication using another channel by switching the port switch.
It is also possible to perform communication using two channels simultaneously. [Fifth Embodiment] The first embodiment is based on the system configuration shown in FIG.
The wireless communication is performed with the wireless communication device 101 by connecting to the HS slave device 104 by wire. However, if the data terminal 105
It is also possible to adopt a system configuration in which it is connected to hardware for performing S data communication processing, and this hardware is connected to a PHS telephone.

FIG. 20 is a block diagram showing the configuration of the radio communication system in this case.

In the figure, a radio communication device 1801 connected to ISDN 1806 has a PHS telephone 180
2. The PHS slave unit 1804 is wirelessly connected, and the PC 180
3 is connected by a wired cable. Further, a hardware processing unit 1807 for performing PHS data communication processing is connected to the PHS slave unit 1804, and a data terminal 1805 is connected to the hardware processing unit 1807.

It is to be noted that a program for performing the processing of each embodiment as described above is stored in a floppy disk, a hard disk, a CD-ROM, a memory card, or the like in advance, and is loaded into the wireless communication device for processing. The system may have a simple configuration.

[0158]

As described above, according to the present invention,
When the data error rate in the wireless section is detected and the data error rate worsens, the error correction data in the wireless communication frame is replaced and the wireless communication frame is retransmitted. Can prevent a decrease in throughput.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a hardware configuration of a wireless communication device according to a first embodiment of the present invention.

FIG. 2 is a block diagram illustrating a configuration of a wireless communication system according to the first embodiment.

FIG. 3 is a block diagram showing a detailed configuration of a PHS master unit in the first embodiment.

FIG. 4 is a block diagram showing a detailed configuration of a switch in the first embodiment.

FIG. 5 is a block diagram showing a detailed configuration of a switch in the first embodiment.

FIG. 6 is a block diagram showing a detailed configuration of a port switch in the first embodiment.

FIG. 7 is a block diagram showing a detailed configuration of an analog switch in the first embodiment.

FIG. 8 is a block diagram showing a detailed configuration of a PHS slave unit in the first embodiment.

FIG. 9 is a flowchart showing a process of the wireless communication device in the first embodiment.

FIG. 10 is a flowchart showing a process of the wireless communication device in the first embodiment.

FIG. 11 is a flowchart showing a process of the wireless communication device in the first embodiment.

FIG. 12 is a flowchart showing a process of the wireless communication device in the first embodiment.

FIG. 13 is a flowchart showing a process of the PHS slave unit in the first embodiment.

FIG. 14 is a flowchart showing a process of the PHS slave unit in the first embodiment.

FIG. 15 is a flowchart showing a process of the PHS slave unit in the first embodiment.

FIG. 16 is a flowchart showing a process of the PHS slave unit in the first embodiment.

FIG. 17 is an explanatory diagram showing a sequence of a control message in the first embodiment.

FIG. 18 is an explanatory diagram showing a sequence of a control message in the first embodiment.

FIG. 19 is a block diagram illustrating a hardware configuration of a wireless communication device according to a second embodiment of the present invention.

FIG. 20 is a block diagram illustrating a configuration of a wireless communication system according to a fifth embodiment of the present invention.

FIG. 21 is an explanatory diagram showing a sequence of a control command in a conventional wireless communication system.

[Explanation of symbols]

 101: wireless communication device, 102: PHS telephone, 103, 105: data terminal, 104: PHS slave, 106: ISDN.

 ──────────────────────────────────────────────────続 き Continued on the front page F-term (reference) QQ20

Claims (16)

[Claims] 1. A wireless communication system comprising: a wireless communication device which can be a wireless master station having connection means for connecting to a digital public communication network; and a wireless communication device which can be a wireless slave station wirelessly accommodated in the wireless master station. In the wireless master station, detecting means for detecting a data error rate in a wireless section, and when the data error rate in the wireless section deteriorates, replaces error correction data of the wireless communication frame and re-executes the wireless communication frame. A wireless communication system comprising: retransmission means for performing transmission. 2. The wireless master station according to claim 1, wherein the wireless master station is connected to the data terminal by wire or wireless, a wireless connection means is wirelessly connected to the wireless slave station, and data transmitted from the data terminal. And a selecting means for selecting audio data transmitted from the wireless slave station; and a transmitting means for transmitting the data selected by the selecting means to a public communication line. 3. The communication device according to claim 1, wherein the selection unit selects which channel of a public communication line to output the data transmitted from the data terminal and the voice data transmitted from the wireless slave station, The transmitting means,
A wireless communication system, wherein data is transmitted to a public communication line in accordance with a result of the selection by the selection means. 4. The radio base station according to claim 1, wherein the wireless master station stores data received from a data terminal connected by wire in a memory, and data stored in the memory. To serial data of a predetermined format. The selecting means includes one or two of data received from a wirelessly connected data terminal, audio data transmitted from a wireless telephone, and the serial data. Wireless communication system, wherein the transmitting means transmits the data selected by the selecting means to a digital public communication line. 5. The wireless master station according to claim 1, wherein the wireless master station wirelessly communicates with the wireless slave station, and wirelessly connects to a plurality of wireless telephones. And a wired communication unit for performing wired communication with the data terminal, wherein the selection unit selects one or two from data transmitted from the data terminal and a plurality of voice data transmitted from the wireless telephone. And the transmitting means transmits the data selected by the selecting means to a public communication line. 6. The wireless master station according to claim 1, further comprising means for performing transmission rate conversion processing when data is not input to a wireless data transmission protocol processing unit. Wireless communication system. 7. The radio base station according to claim 1, wherein the radio master station determines a signal selection in the selection unit by an information element type in a line connection control message transmitted from a radio telephone or a data terminal. A wireless communication system comprising means for switching a combination. 8. The radio base station according to claim 1, wherein the wireless master station is included in a control message transmitted from a wirelessly connected data terminal or a wireless slave station connected to the data terminal. A wireless communication system comprising: means for controlling not to perform an echo cancellation process when a communication attribute indicated is digital data. 9. The radio base station according to claim 1, wherein the radio base station includes an assembling / disassembling means for assembling / disassembling the time division multiplex frame, and a multiplied clock synchronized with a clock extracted from a public communication line. A radio communication system, comprising: a multiplied clock generating means for generating a clock; and a control means for controlling assembling / disassembling of a time division multiplexed frame in synchronization with the generated clock. 10. The multiplied clock generating means according to claim 9, wherein the multiplied clock generating means divides the generated clock, a comparing means which compares a phase of the divided clock with a phase of a clock extracted from a public communication line, Filter means for filtering the result of the comparison, and input the filtered output to the voltage controlled oscillator,
A wireless communication system, comprising: frequency control means for changing the frequency of a clock generated according to a phase difference; and frequency limiting means for limiting the frequency of a generated clock to a value within a predetermined range. . 11. The wireless master station according to claim 1, wherein the wireless master station communicates with the wireless slave station and a public line communication protocol that communicates with the public communication line. And first conversion means for converting a communication data string received using the wireless communication protocol between the wireless slave station and the communication data string into a communication data string synchronized with the public communication line. A second conversion unit that converts a communication data string received from the public communication line into a communication data string synchronized with wireless communication, and performs speed conversion to respective communication speeds of the wireless communication and the wired communication by the public communication line. A wireless communication system, comprising: 12. The wireless master station according to claim 1, wherein the wireless master station assembles / disassembles a communication frame for performing wireless data communication with a wireless slave station; Synchronization establishing means for establishing synchronization of a communication frame for performing communication, retransmission means for retransmitting a communication frame for performing wireless data communication, error detecting means for detecting an error of a communication frame for performing wireless data communication, and the data communication A wired communication unit for wired connection with the terminal, and a conversion unit for converting a data format between communication data exchanged with the data communication terminal and the wireless data communication unit using the wired communication unit. A wireless communication system, comprising: 13. The wireless slave station according to claim 1, wherein the wireless slave station exchanges communication data with a data terminal by wire communication means, and wirelessly communicates with the wireless master station. Wireless communication means for performing wireless data communication with the wireless master station; assembling / disassembling means for assembling / disassembling a communication frame used when performing wireless data communication with the wireless master station; and establishing synchronization for establishing synchronization of the communication frame performing wireless data communication. A wireless communication system comprising: means; retransmission means for retransmitting a communication frame for performing wireless data communication; and error detection means for detecting an error in a communication frame for performing wireless data communication. 14. The radio base station according to claim 1, wherein the radio base station includes: an error correction coding unit that is used when transmitting data to the radio slave station; Error correction decoding means to be used, measuring means for measuring the frequency of data errors in wireless communication between the wireless slave stations, and when the data error rate measured by the error measuring means exceeds a predetermined value, A means for performing error correction by the error correction coding means and the decoding means. 15. The wireless slave station according to claim 1, wherein the wireless slave station includes: an error correction encoding unit that is used when transmitting data to the wireless master station; and when receiving data from the wireless master station. Error correction decoding means to be used, measuring means for measuring the frequency of data errors in wireless communication between the wireless master station, and when the data error rate measured by the error measuring means exceeds a predetermined value, A means for performing error correction by the error correction coding means and the decoding means. 16. The radio base station and the radio slave station according to claim 1, wherein the radio base station and the radio slave station perform radio data communication using the error correction coding unit and the error correction decoding unit. Means for switching whether or not the current wireless data communication uses the error correction coding means and the error correction decoding means. system.