AU5598899A - Wireless facsimile system and facsimile converter therefor - Google Patents

Description

S F Ref: 482890

AUSTRALIA

PATENTS ACT 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT

ORIGINAL

Name and Address of Applicant: Actual Inventor(s): Address for Service: Invention Title: NEC Corporation 7-1, Shiba Minato-ku Tokyo

JAPAN

Miklo Fukushi Spruson Ferguson, Patent Attorneys Level 33 St Martins Tower, 31 Market Street Sydney, New South Wales, 2000, Australia Wireless Facsimile System and Facsimile Converter Therefor The following statement is a full description of this Invention, including the best method of performing it known to me/us:- 5845 10/20 WED 10:57 FAX 03 3288 3222 Katsuragi Patent SPRUSON&FERGUSON 1003/041 WIRELESS FACSIMILE SYSTEM AND FACSIMILE CONVERTER THEREFOR BACKGROUND OF THE INVENTION S 1. Field of the invention The present invention generally relates to wireless data communication systems, and in particular to a facsimile-data transmission system for transmitting facsimile data through a wireless data communication system.

2. Description of the Related Art With the widespread use of mobile communications, the need for transmitting facsimile data via a wireless data transmission 10 system is increasing. To meet such needs, there has been proposed a wireless facsimile system making use of a digital cordless telephone system such as PHS (Personal Handy-phone System) in SJapanese Patent Unexamined Publication No. 10-173803. In this conventional wireless facsimile system using PHS network, a 15 facsimile machine is provided with a PHS communication interface and/or a PHS terminal, allowing radio communication with a nearby PHS base station. In the case of a facsimile transmission control protocol conforming to ITU-T Recommendation T.30, a signal frame conforming to T.30 is transmitted as it is from the facsimile machine to the PHS network through the PHS communication interface or the PHS terminal and vice versa.

However, the wireless transmission section is more likely to cause a burst error, compared with the wired transmission 1999 10/20 WED 10:58 FAX 03 3288 3222 Katsuragi Patent SPRUSON&FERGUSON 9004/041 FO5-431 2 section. Since the.ITU-T Recommendation T.30 is designed for wired communication, there is a high possibility that the frame receiving check timer of the ITU-T Recommendation T.30 reaches the predetermined timeout period. When the timeout occurs, the frame retransmission is performed. As to the response frame to the retransmitted frame, the timeout is also likely to occur. As a result, it is difficult to establish the facsimile transmission.

Further, in the case of ECM-mode image data transmission and reception, the increased error rate in the wireless transmission section causes the response check timer to easily reach a predetermined timeout period.

SUMMARY OF THE INVENTION i An object of the present invention is to provide a wireless facsimile system and a facsimile converter therefor, which can 15 ensure reliable and stable facsimile transmission via a wireless communication line.

According to the present invention, in a wireless facsimile system comprising a wireless communication network and a wired communication network, there are provided a computer having a facsimile modem control function and a wireless communication device connected to the computer. The system further includes a facsimile converter connected to the wireless communication network and the wired communication network, the facsimile 1999 10/20 WED 10:58 FAX 03 3288 3222 Katsuragi Patent SPRUSON&FERGUSON 9005/041 FQ5-431 3 converter converting received data between wireless communication protocol and facsimile communication protocol. A facsimile device is connected to the wired communication network.

The computer may control the facsimile converter using the facsimile modem control function through the wireless communication network. The computer preferably controls the facsimile converter using AT command set. In the wireless facsimile system, non-framed image data conforming to the wireless communication protocol is transmitted between the computer and the facsimile converter based on the wireless communication protocol. Further, framed image data conforming to the facsimile communication protocol is transmitted between the facsimile converter and the facsimile device.

The wireless communication protocol preferably includes a 15 resending control. More specifically, the wireless communication protocol conforms to PIAFS protocol implementing Automatic Repeat Request (ARQ) control. The facsimile communication protocol may conform to ITU-T Recommendation According to another aspect of the present invention, a 20 facsimile converter connects a wireless communication network and a wired communication network. A computer is connected to the wireless communication network and a facsimile device is connected to the wired communication network. The facsimile converter includes a first protocol controller for exchanging data with the computer based on a wireless communication protocol through the wireless communication network, and a second protocol controller .1999 10/20 WED 10:59 FAX 03 3288 3222 Katsuragi Patent SPRUSON&FERGUSON 006/041 FQ5-431 4 performing a facsimile communication protocol under control of the first protocol controller to communicate with the facsimile device through the wired communication network.

According to further another aspect of the present invention, facsimile data is transmitted from the computer to the facsimile converter through the wireless communication network according to a wireless communication protocol. At the facsimile converter, the facsimile data is converted to framed data conforming to a facsimile communication protocol. The framed data is transmitted from the facsimile converter to the facsimile device through the wired communication network.

As described above, according to the present invention, S. frames conforming to the facsimile communication protocol are not e transmitted through the wireless communication network but 15 through the wired communication network between the facsimile *go converter and the facsimile device. The parameter information is transmitted through the wireless communication network according to the wireless communication protocol. Therefore.

compared with the prior art, the frame length of a command on the 20 wireless communication network is reduced, resulting in improved immunity to burst error and the reduced number of frame resending times. In other words, reliable facsimile transmission through the wireless communication network can be achieved. Further, the image data is also transmitted through the wireless communication network according to the wireless communication protocol. The facsimile converterqperforms the framing of the image data 1999 10/20 WED 10:59' FAX 03 3288 3222 Katsuragi Patent SPRUSON &FERGUSON 11007/041 -431 according to :the fAcsimile~ communication protocol.

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S* S S* 5 S. ~SS BRIEFDESCRIPTION OF THE DRAWINGS Fig. 1 is a block diagram showing a wireless f acsimile system according to an embodiment of the present inventlon; Fig.. 2 is -a block diagram showing an. internal circuit of a card according to the embodiment, wherein the card connects d personal computer and a PHS, terminal; Fi1g. 3 is a block diagram showing an Internal circuiLt of a facsimile converter according to the embodiment: Figs. 4A-4C are sequence diagrams showing an operation of Class-2 facsimile transmissioni and.

Figs. 5A-SC are sequence diagrams showing an operation of Class-i facsimile transmission.

DETAILED DESCRIPTION OF.THE PRE-FERRED EMBODIMENTS

SYSTEM-CONFIGURATION

Ref erring. to Fig.- 1, a personal computer 100 has a facsimile 1999 10/20 WED 11:00 FAX 03 3288 3222 Katsuragi Patent SPRUSON&FERGUSON 008/041 FQ5-431. 6 mode control application 101 installed therein. Hereinafter, in some cases, facsimile is abbreviated as fax. The facsimile modem control application'101 running on a CPU (not shown) of the personal computer 100 has a control function for a facsimile modem using the well-known AT command set. In this embodiment, EIA Class 1 and Class 2 are supported. In Class 1, most of the fax transmission work conforming to the ITU-T Recommendation T.30 is left to the facsimile modem control application 101. In Class 2, the facsimile modem side performs more of the fax transmission work.

The personal computer 100 has a PCMCIA card 102 (hereafter.

called a card) connected thereto through the well-known PCMCIA interface. Another type of card interface may be used. A serial interface such as. RS-232-C may be also used to connect an 15 adapter-type facsimile mode thereto. The card 102 connects the personal computer 100 and a PHS terminal 103. The card 102 supports the protocol control conforming to PIAFS (PHS Internet Access Forum Standard) which implements the ARQ (Automatic Repeat Request) control of. PHS data communication.

20 A PHS base station 104, which is one of a plurality of PHS base stations, is connected to a PHS network 105, which is further S o connected to a facsimile converter 106. The facsimile converter 106 is installed within a switching office of the carrier. The facsimile converter 106 is connected to a facsimile machine 108 through a switched network 107. The facsimile machine 108 may be connected to an analog subscriber line of a switch of the 1999 10/20 WED 11:00 FAX 03 3288 3222 Katsuragi Patent SPRUSON&FERGUSON I 009/041 FQ5-431 7 switched network 107. The switch converts a digital signal to an analog signal for that analog subscriber line. The facsimile machine 108 may be also connected to an analog port of a terminal adapter (TA) connected to an ISDN line of the switched network 107.

In the case where a facsimile signal is sent from the personal computer 100 to the facsimile machine 108, a radio signal conveying the facsimile signal is transmitted from the PHS terminal 103 to the PHS base station 104 and the facsimile signal is transferred from the PHS base station 104 to the facsimile converter 106 through the PHS network 105. The facsimile converter 106 converts the facsimile signal in such a way as described later and.then the converted facsimile signal is transferred to the facsimile machine 108 through the switched network 107. In the case where a facsimile signal is sent from the facsimile. machine 108 to the personal computer 100, the facsimile signal will travel through the above-mentioned route in the reverse direction.

S. PCMCIA CARD Referring to Fig. 2, the card 102 includes a PCMCIA interface 201, which is used to be connected to the personal computer 100.

The PCMCIA interface 201 is connected to an AT command processor 202 for processing AT commands received from the personal computer *o*ooo 100. The AT command processor 202 is further connected to a PIAFS 25 protocol processor 203, which allows the PHS terminal 103 to be connected thereto. The PIAFS protocol processor 203 performs the 1999 10/20 WED 11:01 FAX 03 3288 3222 Katsuragi Patent SPRUSON&FERGUSON 010/041 FQ5-431 8 protocol control conforming to PIAFS implementing the ARQ control of PHS data communication.

FAX CONVERTER Referring to Fig. 3, the facsimile converter 106 includes a PIAFS controller 301 and a facsimile controller 302. which are connected through RS-232-C interface and analog 2W interface.

Such a configuration is analogous to a case where the analog port of a terminal adapter (TA) is connected to a facsimile device.

The facsimile controller 302 includes an off-hook setting section 303. The facsimile controller 302 is connected to a buffer (not shown) for storing received data. Since the PHS network 105 is usually constructed with ISDN (Integrated Services Digital Network) interfaces, the facsimile converter 106 has an ISDN interface function. It is assumed that the ISDN interface rate consists of two B and one D channels In this case, one B. channel may be used to communicate with the card 102 through the PHS network 105 :and the other B channel may be used to communicate with the facsimile machine 108.

S: The PIAFS controller 301 has a call control function and an AT command extracting function. More specifically, when an S. incoming call from the ISDN interface occurs, the PIAFS controller 301 controls the incoming call process. When PIAFS user information carrying an AT command thereon is received, the PIAFS controller 301 extracts the AT command information from the PIAFS 25 user information. and recognizes, the extracted AT commands as inialat comands. Te AT mmands are transferred to the initialization commands. The AT commands are transferred to the 1999 10/20 WED 11:01 FAX 03 3288 3222 Katsuragi Patent SPRUSON&FERGUSON 1011/041 FQ5-431 9 facsimile controller 302 through the RS-232-C interface.

Thereafter, the PIAFS controller 301 sets ATD commands on the facsimile controller 302.

When the ATD command has been set, the off-hook setting section 303 makes the analog 2W interface off-hook. If a polarity change in the analog 2W interface is detected, the facsimile controller 302 uses one B channel of the ISDN interface to exchange necessary signals with the facsimile machine 108 and further controls the T.30 sequence. The details of communication sequence will be described hereinafter.

FAX COMMUNICATION IN CLASS 2 Figs. 4A-4C show a communication sequence in class 2 according to the ITU-T Recommendation V.34 allowing up to 33.6kbps.

A user of the personal computer 100 registers the telephone number of the facsimile converter 106 in advance in the facsimile modem control application 101. When the user wants to send a fax message to the facsimile machine 108, the user inputs the telephone number of the facsimile machine 108 and then starts the facsimile transmission.

Referring to Fig. 4A. when receiving the facsimile transmission instruction, the facsimile modem control application 101 designates class 2 using AT command set by sending AT FCLASS 2.0 to, the card 102. When receiving +FCLASS 25 from the facsimile modem control application 101, the card 102 S" operates in class 2 from that time. Further, the communication 1999 10/20 WED 11:02 FAX 03 3288 3222 Katsuragi Patent SPRUSON&FERGUSON .9012/041 POQ-431 1 0 speed between the personal computer 100 and the card 102 is set to 38.4kbps.

When receiving a response "OK" from the card 102. the facsimile modem control application 101 sets the parameters for facsimile transmission using +FDCC command consisting of VR (vertical resolution), BR (bit rate), WD (page width), LN (page length). DF (data compression format), EC (error correction), BF (binary file transfer), and ST (scan time/line).

BR (bit rate) is one of 0 to D(H) which indicate 2400bps to 33.6kbps, respectively. Since the data transfer speed of the PHS data communication is 32kbps and the effective speed on the PIAFS protocol is 29.2kbps as of now, BR is set to B(H)=28.8kbps.

If the.PHS data transfer speed is increased, the BR may also be set to a higher value. For example, in the case of PHS data speed becoming 64kbps, the effective speed on the PIAFS protocol is 58.4kbps and therefore BR is set to D(H)=33.6kbps.

Since MMR (modified-modified READ) coding is usually employed in V.34. it is necessary to perform error correction.

Therefore, EC (error correction) is set to 2, which means Enable ECM and 256 bytes/frame.

Inthis way, the facsimile modem control application 101 sends AT +FDCC 0.B'0.0.0.2.0.0 to the card102. Whenreceiving a response "OK" to the +FDCC command from the card 102, the facsimile modem control application 101 sends +FLID command 25 indicating the local identification (ID) to the card 102. The facsile conerter 106 uses the ID designation by +LID command facsimile converter 106 uses the ID designation by +FLID command 1999 10/20 WED 11:02 FAX 03 3288 3222 Katsuragi Patent SPRUSON&FERGUSON 013/041 -431 1 1 to produce TSI (transmission subscriber identification) frames conforming to When receiving a response "OK" to the +FLID command from the card 102, the facsimile modem control application 101 sends an ATD command to the card 102. In this embodiment, the ATD command has such a format as ATDxxx*yyy, where xxx is the telephone number of the facsimile converter 106. yyy is the telephone number of the facsimile machine 108 as a subaddress, and the symbol is a delimiter between them.

When receiving the ATD command ATDxxx*yyy from the personal computer 100, the card 102 instructs the PHS terminal 103 to make a call to the facsimile converter 106 by sending the address xxx and the subaddress yyy to the PHS terminal 103. The xxx is the telephone number of the facsimile converter 106 and the yyy is the telephone number of the facsimile machine 108. This causes the PHS terminal 103 to dial the telephone number xxx of the o. facsimile converter 106 with the telephone number yyy as

F.

subaddress included therein.

When receiving the call from the PHS terminal 103 through S 20 D channel of the PHS network 105, the PIAFS controller 301 of the facsimile converter 106 starts the incoming call sequence to establish the connection to the PHS terminal 103. When the connection has been established, the card 102 sends PIAFS user information carrying +FCLASS parameter +FDCC parameter 25 and +FLID parameter to the facsimile converter 106 through B channel.

1999 10/20 WED 11:03 FAX 03 3288 3222 Katsuragi Patent SPRUSON&FERGUSON i1014/041 FQ5-431 12 When receiving these parameters from the card 102, the PIAFS controller 301 of the facsimile converter 106 sends these parameters as initialization commands to the facsimile controller 302 through the RS-232-C interface to set them on the facsimile controller 302.. Thereafter, the PIAFS controller 301 sets ATD S command for off-hook .on the facsimile controller 302. The ATD command for off-hook causes the off-hook setting section 303 to set the analog 2W interface to the off-hook state.

When detecting the off-hook of the analog 2W interface, the PIAFS controller 301 uses the D channel to dial the subaddress yyy of the facsimile machine 108 connected to the switched network 107. When detecting the polarity change from the facsimile machine 108. the PIAFS controller 301 changes the polarity of the analog 2W interface, allowing data communication with the facsimile machine 108 using the B channel of the ISDN.

When detecting the polarity change in the analog 2W interface after setting the analog 2W interface to off-hook, the facsimile controller 302 produces a calling tone (CNG) signal to send it to the PIAFS controller 301 through the analog 2W interface.

The PIAFS controller 301 converts the CNG signal into digital to send it to the facsimile machine 108 through the B channel.

Similarly, a signal to be transmitted from the facsimile controller 302 to the facsimile machine 108 is transferred to the PIAFS controller 301 through the analog 2W interface. The signal 25 is converted into digital by the PIAFS controller 301 and then is sent to the facsimile machine 108 through the B channel.

1999 10/20 WED 11:03 FAX 03..3288 3222 Katsuragi Patent SPRUSON&FERGUSON I015/041 FQ5-431 13 Contrarily, a digital signal received from the facsimile machine 108 is converted into analog by the PIAFS controller 301 and is then transferred to the facsimile controller 302 through the analog 2W interface.

In the case of the facsimile machine 108 having the V.34 function, the facsimile converter 106 receives a modulated answer tone (ANSam) signal from the facsimile machine 108. When receiving the ANSam signal, the facsimile controller 302 sends a call menu (CM) signal to the facsimile machine 108. In response to the CM signal, the facsimile machine 108 sends a joint menu (JM) signal back to the facsimile controller 302. When receiving the JM signal, the facsimile controller 302 determines that V.34 communication with the facsimile machine 108 is possible, and then outputs "CONNECT" to the PIAFS controller 301 through the RS- 232-C interface.

When receiving "CONNECT" from the facsimile controller 302, Sthe PIAFS controller 301 determines the ready-to-communicate Sstate and sends a.frame carrying "PIAFS user information completion" to the card 102. The card 102, when receiving the frame, outputs +FCON command to the facsimile mode control application 101 of the personal computer 100.

On the other hand, V8 negotiation is performed between the facsimile controller 302 and the facsimile machine 108 and then S modem training is performed by the facsimile controller 302 25 sending a training (TRN) signal for checking the line bandwidth.

Referring to Fig. 4B, after the modem training, the 1999 10/20 WED 11:04 FAX 03 3288 3222 Katsuragi Patent SPRUSON&FERGUSON.

I016/041 F05-431 facsimile controller 302 sequentially receives a called subscriber identification (CSI) signal and a digital identification (DIS) signal from the facsimile machine 108. In response to these CSI and DIS signals, the facsimile controller 302 outputs respective transmission requests for response commands +FCIS and ,+FDIS to the PIAFS controller 301. Upon receipt of the transmission requests, the PIAFS controller 301 sends the response commands +FCIS and +FDIS in form of PIAFS frame to the card 102.

The card 102. when receiving the response commands +FCIS and +FDIS,..transfers them to the personal computer 100. The facsimile mode control application 101 outputs +FDT command to the card 102 in response to the response commands +FCIS and +FDIS and the card 102 transmits it to the facsimile converter 106.

When receiving the +FDT command from the card 102, the facsimile controller 302 sends the TSI signal and a digital command signal (DCS) to the facsimile machine 108. At the time when the DSC signal has been sent, the parameters for communication with the facsimile machine 108 are determined. Therefore, the facsimile controller 302 instructs the PIAFS controller 301 to send a response command +FDCS carrying the parameter determination result to the card 102. Following the instruction from the facsimile controller 302, the PIAFS controller 301 sends the response command +FDCS to the card 102 in form of PIAFS frame.

25 When receiving a confirmation to receive (CFR) signal from the facsimile machine 108, the facsimile controller 302 instructs the a 0 WO. 0 0 0* 0 0* S1999 10/20 WED 11:04 FAX 03 3288 3222 Katsuragi Patent SPRUSON&FERGUSON I017/041 FQ5-431 PIAFS controller 301 to send "CONNECT" and "XON" to the card 102.

Following the instruction from the facsimile controller 302, the PIAFS controller 301 sends "CONNECT" and "XON' to the card 102 in form of PIAFS frame. The card 102 transfers the received +FDCS, CONNECT and XON frames to the personal computer 100. When "XON" is received, the facsimile modem control application 101 determines that the flow control is released and starts sending image data to the card 102.

The image data is encoded according to MMR coding and the MMR coded image data is transferred from the card 102 to the facsimile converter? 106. The facsimile converter 106 converts the MMR coded image data to ECM mode image data and sends the ECM-mode image data to the facsimile machine 108. In ECM mode, the image data is transmitted in units of 256 frames each frame having 64 or 256 bytes. Framing of image data is performed by the facsimile converter 106.

More specifically, the facsimile modem control application 101 .sends MMR-coded image data which is not subject to framing, the MMR-coded image data having a termination code <DLE><ETX> added to the tail end thereof, Therefore, in the radio line section, the resending control due to errors is performed by PIAFS protocol, not by ECM mode. This allows the facsimile controller S' 302 of the facsimile converter 106 to receive error-free MMRcoded image data froifm the card 102. When all MMR-coded image data 25 have been received from the card 102, the facsimile controller 302 sends "OK" to the card 102 so as to request an AT+FET command 1999 10/20 WED 11:05 FAX 03 3288 3222 Katsuragi Patent SPRUSON&FERGUSON 1I018/041 FQ5-431 1 6 indicating whether a next page to be sent is left. In the case of Fig.4B, the command AT FET 2 is received from the card 102, which means that no page to be sent is left.

The facsimile controller 302 frames the received MMR-coded image data to transmit the image data in units of 256 frames to the facsimile machine 108. Every time a set of 256 frames has been sent, a PPL-NULL signal is sent to the facsimile machine 108.

In response to the PLL-NULL signal, the facsimile machine 108 sends a message confirmation (MCF) signal back to the facsimile controller 302. When having sent all the MMR-coded image data to the facsimile machine 108, the facsimile controller 302 sends a PPS-EOP signal to the facsimile machine 108. The PPS-EOP signal is a termination signal indicating that there is no page to be sent. In response to the PLL-EOP signal, the facsimile machine 108 sends a MCF signal back to the facsimile controller 302.

When receiving the MCF signal from the facsimile machine 108, the facsimile controller 302 instructs the PIAFS controller 301 to send a response indicating normal reception of the MCF signal to the card 102. Following the instruction from the facsimile controlley 302, the PIAFS controller 301 sends a response command +EPTS:1 and a code +FHNG:00 to the card 102 in form of PIAFS frame.

Referring to Fig. 4C, the card 102, when receiving the response command +FPTS:1 and the code +FHNG:00, transfers them 25 to the facsimile modem control application 101. The code +FHNG: 00 causes the faosimile modem control application 101 to be informed 1999 10/20 WED 11:05 FAX 03 3288 3222 Katsuragi Patent SPRUSON&FERGUSON 019/041 FQ5-431 P 1 7 of normal image transmission to the facsimile machine 108.

Further, when receiving "OK" following the code +FHNG:00 from the facsimile converter 106, the card 102 transfers it to the facsimile modem control application 101. Then, the facsimile modem control application 101 sends ATM command to the card 102 so as to disconnect the established connection. On the other hand, the facsimile controller 302 sends a disconnect (DCN) signal to the facsimile machine 108 to disconnect the established connection.

As described above, in the case of class 2 facsimile communication using a.PHS line, frames conforming to T. 30 are not transmitted through the wireless line but through the wired line between the facsimile converter 106 and the facsimile machine 108.

The AT command information is transmitted through the wireless line according to PIAFS protocol. Therefore, compared with the prior art, the frame length of a command on the wireless line is reduced, resulting in improved immunity to burst error and the reduced number of frame resending times. In other words, reliable facsimile transmission using the PHS communication system can be achieved. Further, the MMR-coded data is also transmitted e through the wireless line according to PIAFS protocol. The facsimile controller 302 of the facsimile converter 106 performs the framing of the MMR-coded data according to In this manner, the frame resending caused by errors occurring in the radio line is performed according to the PIAFS 25 protocol. The frame resending caused by errors occurring in the wired line is performed by the facsimile controller 302 of the 1999 10/20 WED 11:06 FAX 03 3288 3222 Katsuragi Patent SPRUSON&FERGUSON 1 020/041 P5-431 18 facsimile converter 106. In other words, the MMR-coded data framed based on T.30 is transferred through only the wired line.

Therefore, the problem of the prior art that the response monitoring timer easily reaches the predetermined timeout period can be eliminated by the present invention.

In the case where the wireless line provides a lower error rate and the wired line provides a higher error rate, the facsimile controller 302 turns off the CS line of the RS-232C interface.

This causes the PIAFS controller 301 to be informed that new data cannot be supplied to the facsimile controller 302 and thereby to perform the flow control on the PIAFS protocol. Therefore, the buffer (not shown) in the facsimile controller 302 is prevented from becoming full.r FAX COMMUNICATION IN CLASS 1 The present invention is applicable to.not only class 2 facsimile operation but also class 1 facsimile operation.

SFigs. 5A-5C show a communication sequence in class 1 according-to the ITU-T Recommendation V.34 allowing up to 33.6kbps.

Referring to Fig. 5A, when receiving the facsimile transmission instruction, the facsimile modem control application 101 designates class 1 using AT command set by sending "AT FCLASS 1.0 to the card 102. When receiving +FCLASS from the facsimile modem control application 101, the card 102 25 operates in class 2 from that time. When receiving a response "OK" from the card 102. the facsimile modem control application 1999 10/20 WED 11:06 FAX 03 3288 3222 Katsuragi Patent SPRUSON&FERGUSON 19021/041 FQS-431 19 101 sets the parameters for facsimile transmission using AT F34 command. In this embodiment, the maximum rate of image data is set to 12 (28.8kbps V.34), the minimum rate of image data is set to 1 (2400bps V.34), and the rate of the control channel is set to 2 (2400bps).

In this way, the facsimile modem control application 101 sends AT.+ F34 12.1.2 to the card 102. When receiving a response "OK" from the card 102, the facsimile modem control application 101 sends an ATD cotmmand to the card 102. In this embodiment, the ATD command has such a format as ATDxxx*yyy. where xxx is the telephone number of the facsimile converter 106, yyy is the telephone number of the facsimile machine 108 as a subaddress, and the symbol is a delimiter between them.

When receiving the ATD command ATDxxx*yyy from the personal computer 100, the card 102 instructs the PHS terminal 103 to make a call to the facsimile converter 106 by sending the address xxx and the subaddress yyy to the PHS terminal 103. The xxx is the telephone number of the facsimile converter 106 and the yyy is S" the telephone number of the facsimile machine 108. This causes the PHS terminal 103 to dial the telephone number xxx of the facsimile converter 106 with the telephone number yyy as subaddress includedl therein.

When receiving the call from the PHS terminal 103 through D channel of the PHS network 105, the PIAFS controller 301 of the 25 facsimile converter 106 starts the incoming call sequence to establish the connection to the PHS terminal 103. When the 1999 10/20 WED 11:07 FAX 03 3288 3222 Katsuragi Patent SPRUSON&FERGUSON 9022/041 FQ-431 connection has been established, the card 102 sends PIAFS user information carrying +FCLASS parameter 1.0) and +F34 parameter to the facsimile converter 106.

When receiving these parameters from the card 102. the PIAFS controller 301 of the facsimile converter 106 sends these parameters as initialization commands to the facsimile controller 302 through the RS-232-C interface to set them on the facsimile controller 302. Thereafter, the PIAFS controller 301 sets ATD command for off-hook oh the facsimile controller. 302. The ATD command for off-hook causes the off-hook setting section 303 to set the analog 2W interface to the off-hook state.

When detecting the off-hook of the analog 2W interface, the PIAFS controller 301 uses the D channel to dial the subaddress yyy of the facsimile machine 108 connected to the switched network 107. When detecting the polarity change from the facsimile machine 108, the PIAFS controller 301 changes the polarity of the analog 2W interface, allowing data communication with the facsimile machine 108 using the B channel of the ISDN.

When detecting the polarity change in the analog 2W interface after setting the analog 2W interface to off-hook, the .facsimile controller 302 produces a calling tone (CNG) signal to send it to the PIAFS controller 301 through the analog 2W interface.

The PIAFS controller 301: converts the CNG signal into digital to Ssend it to the facsimile machine 108 through the B channel.

25 In the case of the facsimile machine 108 having the V.34 function, the facsimile converter 106 receives a modulated answer 1999 10/20 WED 11:07 FAX 03 3288 3222 Katsuragi Patent SPRUSON&FERGUSON I023/041 FQ5-431 2 1 tone (ANSam) signal from the facsimile machine 108. When receiving the ANSam signal, the facsimile controller 302 sends a call menu (CM) signal to the facsimile machine 108. In response to the CM signal, the facsimile machine 108 sends a joint menu (JM) signal back to the facsimile controller 302. When receiving the JM signal, the facsimile controller 302 determines that V.34 communication with the facsimile machine 108 is possible, and then informs the PIAFS controller 301 through the RS-232-C interface of the determination.

When receiving the determination from the facsimile controller 302, the PIAFS controller 301 determines the ready-to-communicate state and sends a frame carrying "PIAFS user information completion" to the card 102. The card 102, when receiving the frame', outputs "CONNECT" to the facsimile mode control application: 101 of the personal computer 100.

On the other hand, V8 negotiation is performed between the facsimile controller 302 and the facsimile machine 108 and then modem training is performed by the facsimile controller 302 sending a training (TRN) signal for checking the line bandwidth.

After the modem training, the PIAFS controller 301 sends codes <p288><DLE><o24> to the card 102 depending on the notice received from the facsimile controller 302. The codes <p288><DLE><o24> indicate that the image data can be transferred at 28.8kbps and the control channel data can be transferred at 2400bps.

25 When receiving a called subscriber identification (CSI) signal from the facsimile machine 108, the PIAFS controller 301 1999 10/20 WED 11:08 FAX 03 3288 222 Katsuragi Patent SPRUSON&FERGUSON 9024/041 FQ05-431 22 codes <CSI><DLE><ETX> indicating the reception of the CSI signal to the card 102 depending on the notice received from the facsimile controller 302. When receiving a digital identification (DIS) signal from the facsimile machine 108, the PIAFS controller 301 codes <DIS><DLE><ETX> indicating the reception of the DIS signal to the card 102 depending on the notice received from the facsimile controller 302. The card 102, when receiving these codes from the facsimile converter 106, transfers them to the personal computer 100.

Referring to Fig. 5B, the facsimile controller 302 produces a TSI signal having a local ID of its own set therein and a digital command signal (DCS) depending on the received Then, the facsimile controller 302 sends the card 102 <TIS><DLE><ETX> indicating the TIS transmission. The card 102 sends the <TIS><DLE><ETX> to the facsimile converter 106 through the PHS terminal 103 and the PHS network 105.

When receiving the <TIS><DLE><ETX>, the PIAFS controller 301 of the facsimile converter 106 instructs the facsimile controller 302 to send the TIS signal. Following the instruction from the PIAFS controller 301, the facsimile controller 302 sends the TIS signal to the facsimile machine 108. Similarly, the facsimile controller. 302 sends the DCS signal to the facsimile machine 108 depending on <DCS><DLE><ETX> received from the facsimile modem control application 101.

25 Further, the facsimile modem control application 101 sends the card 102 a command AT FT 12, which indicates that data •"the card 102 a command AT FTM= 12, which indicates that data 1999 10/20 WED 11:08 FAX 03 3288 3222 Katsuragi Patent SPRUSON&FERGUSON 9025/041 F05-431 23 can be transferred at 28.Skbps. Such. command information is transferred to the facsimile controller 302 through the card 102, PHS network 105 and the .PIAFS controller 301.

Referring to Fig. 5C, when the facsimile controller 302 has received a confirmation to receive (CFR) signal from the facsimile machine 108, the PIAFS controller 301 sends <CFR><DLE><ETX> to the card 102 depending on the notice received from the facsimile controller 302. The card 102 transfers these codes to the personal computer.100. The facsimile modem control application 101 sends the command AT FTM 12 to the card 102. The command information is also ,transferred to the facsimile controller 302 through the card 102, the PHS network 105 and the PIAFS controller 301.

When receiving "OK" from the card 102, the facsimile modem control application 101 sends MMR-coded image data to the facsimile converter 106. The facsimile converter 106 converts the MMR-coded image data to ECM mode image data and sends the ECM-mode image data to the facsimile machine 108. In ECM mode, the image data is transmitted in units of 256 frames each frame having 64 or 256 bytes. Framing of image data is performed by the facsimile converter 106.

More specifically, the facsimile modem control application 101 sends MMR-coded image data which is not subject to framing, the MMR-coded image data having a termination code <DLE><ETX> 25 added to the tail end thereof. Therefore, in the radio line section, the resending control due to errors is performed by PIAFS 1999 10/20 WED 11:09 FAX 03 3288 3222 Katsuragi Patent SPRUSON&FERGUSON 1 026/041 FQ5-431 24 protocol, not by ECM mode. This allows the facsimile controller 302 of the facsimile converter 106 to receive error-free MMRcoded image data from the card 102. When all MMR-coded image data have been received from the card 102, the facsimile controller 302 sends "OK" to the card 102. When receiving "OK" from the facsimile converter 106 through the card 102, the facsimile modem control application 101 produces a termination signal. In the case of Fig. 5C, a PPS-EOP signal is produced as the termination signal indicating that there is no page to be sent.

The facsimile modem control application 101 outputs <PPS-EOP><DLE><ETX> indicating the transmission of the PPS-EOP signal to the card 102. The card 102 sends <PPS-EOP><DLE><ETX> to the facsimile converter 106 through the PHS terminal 103 and the PHS network 105. When receiving the <PPS-EOP><DLE><ETX>, the PIAFS controller 301;of the facsimile converter 106 instructs the facsimile controllet 302 to send the PPS-EOP signal to the facsimile machine 108. Following the instruction from the PIAFS Scontroller 301, the facsimile controller 302 sends the PPS-EOP .signal to the facsimile machine 108.

When receiving the MCF signal from the facsimile machine 108, the PIAFS controller 301 sends <MCF><DLE><ETX> indicating normal reception of ,the MCF signal to the card 102 depending on the notice received from the facsimile controller 302. The facsimile modem control application 101, when receiving 25. <MCF><DLE><ETX> from the facsimile converter 106 through the card 102 outputs DCNETX indicating thetransmission of the .102. outputs <DCN><DLE><ETX> indicating the transmission of the 1999 10/20 WED 11:09 FAX 03 3288 3222 Katsuragi Patent SPRUSON&FERGUSON 2027/041 FQ5-431 2 DCN signal to the card 102. The card 102 sends <DCN><DLE><ETX> to the facsimile converter 106 through the PHS terminal 103 and the PHS network 105. When receiving <DCN><DLE><ETX>. the PIAFS controller 301 instructs the facsimile controller 302 to send the DCN signal. Following the instruction, the facsimile controller 302 sends the DCN signal to the facsimile machine 108 to disconnect the established connection. Then, the facsimile modem control application 101 sends ATH command to the card 102 so as to disconnect the established connection.

As described above, in the case of class 1 facsimile communication using a PHS line, frames conforming to T.30 are not transmitted through the wireless line but through the wired line between the facsimile converter 106 and the facsimile machine 108.

Therefore, in this embodiment, the frame length of a command on the wireless line is reduced, resulting in improved immunity to burst error and the reduced number of frame resending times. In other words, reliable facsimile transmission using the PHS communication system can be achieved. Further, the MMR-coded data is also transmitted through the wireless line according to PIAFS protocol. The facsimile controller 302 of the facsimile converter 106 performs the framing of the MMR-coded data according to In this manner, the frame resending caused by errors occurring in the radio line is performed according to the PIAFS 25 protocol. The frame resending caused by errors occurring in the wired line is performed by the facsimile controller 302 of the 1999 10/20 WED 11:10 FAX 03 3288 3222 Katsuragi Patent SPRUSON&FERGUSON 1028/041 F05-431 26 facsimile converter 106.. In other words, the MMR-coded data framed based on T.30; is transferred through only the wired line.

Therefore, the problem of the prior art that the response monitoring timer easily reaches the predetermined timeout period can be eliminated by the present embodiment.

It should be noted that the facsimile converter 106 sends "OK" to the card 102 at the time when all MMR-coded data have been sent to the facsimile machine 108 in ECM mode. Therefore, it takes some time required from when the card 102 has sent all the MMR-coded data to the facsimile converter 106 to when the card 102 receives "OK" from the facsimile converter 106. In this period, the PIAFS controller 301 performs the flow control according to the PIAFS protocol.

The present invention is also applicable to facsimile communication conforming to ITU-T Recommendation V.17 which defines the maximum ,communication speed of 14.4kbps.

9.

Claims (9)

1. A wireless facsimile system comprising a wireless communication network and a wired communication network, further comprising: a computer having a facsimile modem control function; a wireless communication device connected to the computer; a facsimile converter connected to the wireless communication network and the wired communication network, the facsimile converter converting received data between wireless communication protocol and facsimile communication protocol; and a facsimile device connected to the wired communication network.

2. A wireless facsimile system according to claim 1, wherein the computer controls the facsimile converter using the facsimile modem control function through the wireless communication network.

3. A wireless facsimile system according to claim 2, wherein the computer controls the facsimile converter using AT command set. 20 A wireless facsmile system ccording to claim 20 4. A wireless facsimile system according to claim 1, i. 1999 10/20 WED 11:11 FAX 03 3288 3222 Katsuragi Patent SPRUSON&FERGUSON 10030/041 FQ5-431 28 wherein: non-framed image data conforming to the wireless communication protocol is transmitted between the computer and the facsimile converter based on the wireless communication protocol; and framed image data conforming to the facsimile communication protocol.is transmitted between the facsimile converter and the facsimile device. A wireless facsimile system according to claim 1, wherein the wireless communication protocol includes a resending control.

6. A wireless facsimile system according to claim wherein the wireless communication protocol conforms to PIAFS protocol implementing Automatic Repeat Request (ARQ) control. 15 7. A wireless facsimile system according to claim 1, S: wherein the facsimile communication protocol conforms to ITU- T Recommendation

8. A wireless facsimile system comprising a wireless communication network and a wired communication network, further comprising: a computer for producing parameter and image data which are used for facsimile communication; 1999 10/20 WED 11:11 FAX 03 3288 3222 Katsuragi Patent SPRUSON&FERGUSON @031/041 FQ5-431 29 a wireless communication device connected to the computer, for transmitting and receiving the parameter and the image data according to a wireless data communication protocol: a facsimile converter connected to the wireless communication network and the wired communication network, the facsimile converter converting the parameter and the image data received from the computer through the wireless communication neLwork to framed data conforming to a facsimile communication protocol; and a facsimile device connected to the wired communication network, for reproducing the framed image data received from the facsimile converter.

9. Afacsimile converter connecting a wireless communication network and a wired communication network, wherein 15 a computer is connected to the wireless communication network and 9.- .a facsimile device is connected to the wired communication network, comprising: a first protocol controller for exchanging data with the computer based on a wireless communication protocol through S20 the wireless communication network; and 0* a second protocol controller performing a facsimile communication protocol under control of the first protocol controller to communicate with the facsimile device through the wired communication network. 1999 10/20 NED 11: 11 FAX 03 3288 3222 Katsuragi Patent SPRUSON&FERGUS0N 032/041 F05-431 .A f acsimiLle converter. according to claim 9, wherein the f irst protocol controller has an ISDN interface including at least two B channels and a D channel, wherein ohs B channel is used to communicate with the computer and another B channel is used to communicate with the facsimile device. ii. A method for. transmitting facsimile data from a computer to a. f acsimile device through- wireless communication network and a wired communication network, wherein the computer IS connected to the wireless communication network, the f acsimile device Is connected to the wired communication network, and a f acslmlle converter connects. the wireless communication network and the wired communication network, comprising the steps of; transmitting facsimile data from the computer to the facsimile converter through the wireless communication network according to a wireless communication protocol; .converting the facsimile data to framed, datd conf orming to a facsimile communication protocol at the f acsimile converter .and transmitting the framed data from the facsimile converter to the f acsi-mile device through the wired communication network. oseoe. -31

12. A wireless facsimile system comprising a wireless communication network and a wired communication network, said system being substantially as herein described with reference to the drawings.

13. A facsimile converter connecting a wireless communication network and a wired communication network, said converter being substantially as herein described with reference to the drawings.

14. A method for transmitting facsimile data from a computer to a facsimile 0o device through a wireless communication network and a wired communication network, said method being substantially as herein described with reference to the drawings. DATED this Twentieth Day of October, 1999 NEC Corporation Patent Attorneys for the Applicant SPRUSON FERGUSON oC.S o*. *5g CSo CS C [R:\LIBL]00409.doc:BFD