CA2254779A1 - Apparatus and method for facsimile communications - Google Patents

Abstract

A system for delivery of facsimile messages over non real time or a time delayed network, such as the Internet, includes an originating conversion and routing device connecting a source facsimile device to an Internet service provider. A destination conversion and routing device interconnects the Internet and the public switched telephone network and a Hub controls the data intercommunication between the originating and destination devices.

Description

CA 022~4779 1998-11-18 APPARATUS AND METHOD FOR FACSIMILE
COMMUNICATIONS OVER A VARYING DELAY LINK

Field of the Invention This invention relates to telecommunications methods and apparatus and more particularly to methods and apparatus to facilitate delivery of facsimile transmissions over a varying time delay network.

Background of the Invention Facsimile (fax) transmission of documents over the public switched telephone network (PSTN) is accomplished by connecting a facsimile machine to a subscriber's telephone loop or drop and operating the facsimile device to provide a destination telephone number of a fax device interconnected with the PSTN. A call is established over the PSTN to enable the destination fax machine to receive the data produced by the originating fax device which represents the images contained on papers scanned by the originating fax device. Current protocols for communications by facsimile devices to deliver documents requires the communications channel interconnecting the originating fax device to the destination fax device have a turn around time delay which does not exceed a certain threshold time. Commonly, the threshold time period is in the range of 80 milliseconds.

Prior art facsimile systems have been proposed, such as that by Gordon et al. in U.S. Patent 4,994,926 and Bloomfield et al. in U.S. Patent 5,555,100 which describe facsimile store and forward systems having local interface apparatus totranslate dual tone multifrequency (DTMF) signals into store and forward system commands. These store and forward systems provide a method of operation and apparatus to guarantee the delivery of a fax using a store and forward service. In this arrangement of store and forward systems, if the destination fax device is unavailable, the store and forward services will receive the fax transmission and forward the fax CA 022~4779 1998-11-18 transmission to the destination fax machine at a later time when the destination fax device is available. Other variations of the store and forward service include provision of security methods to avoid interception of, or misdelivery of, the facsimile data to the destination fax device. The communications channel relied on in the prior art are the public switched telephone network which provides a circuit switch connection without interfering delay between the source fax machine and the destination fax machine.
Where the store and forward service retains a copy of the fax data for subsequent delivery, communications between the source fax machine and the store and forward system occur over the public switched telephone network. Similarly, when the fax data is to be delivered to the destination fax machine, the public switched telephone network is used to accomplish that communications.

Such store and forward systems rely on a communications channel with a substantially invariable time delay or a time delay that cannot exceed a threshold amount of, for example, greater than 80 milliseconds. Thus, in these prior art arrangements, the maximum delay inherent in the various fax transmission channels does not have the potential to interfere with or disrupt the facsimile transmission.
Where real time channel delays exceed threshold amounts, a communications error is triggered and/or the facsimile message transmission is aborted.

Summary of the Invention The method and apparatus of the invention permit the use of fax machines, which are configured to interconnect with the public switched telephone network, to be interconnected by alternative time delayed communications channels other than the public switched telephone network on which they are designed to operate. In accordance with the invention, there is no longer a need for a real time or a direct or circuit switched connection between a source and a destination fax device.

The invention provides a sending data conversion and routing device (SDCR) which allows communications technologies to be employed to carry facsimile data communications over communications channels that have turn-around or CA 022~4779 1998-11-18 t propagation delays exceeding those that are required to create a direct or circuit switched connection. Example communications channels that are subject to long orexcessive propagation delay include TCP/IP networks, including the Internet, hyper stream and satellite systems providing switched facilities such as MSAT and the like.

By enabling fax transmissions to occur over propagation delayed communications channels, the range of communications options available for delivery of fax transmissions can be expanded to lower the cost of communications and to provide communications in remote and inaccessible areas that would otherwise not be available to facsimile transmission.

Description of the Invention For selection of a conventional PSTN facsimile transmission, a sending data conversion and routing device (SDCR) becomes a "pass through" device which allows direct interconnection of the source fax device to the public switched telephone network for interconnection with the destination fax device.

For the selection of alternative communications to the public switched telephone network where the communications channel is not real time that is it involves a time delay that exceeds the operating requirements of facsimile telecommunications, the SDCR device simulates a destination fax device to capture into SDCR memory the fax routing information and fax data which originates from the source fax device. The captured data is converted into a binary format that can be transmitted over thecommunications channel selected irrespective of the channel latency or delay times.
The captured data may be co",,l~ressed to reduce transmission times. The data is then transmitted over the communications channel using a communication protocol that guarantees data integrity. The SDCR establishes a communications channel to a fax Hub which contains routing dat~h~ses. The SDCR and the fax Hub exchange information to direct routing of the data to accomplish delivery of the captured data to a destination data conversion and routing device (DDCR) interconnectable with the CA 022~4779 1998-11-18 destination or target fax device. If the DDCR is busy, the fax Hub will receive and store the data. If the DDCR is not busy, the data is transmitted from the SDCR to the DDCR.

The fax Hub transmits the binary data using communications channel routing based on the communications channels available to communicate with the 5 destination fax device. The fax Hub can transmit binary data using the communications channel selected to a destination data conversion and routing device (DDCR). TheDDCR is interconnected on one side to the time delayed communications channel for communication with either the Hub or an SDCR. On the other side, the DDCR is connected to the PSTN which facilitates delivery of the fax data from the DDCR to the 10 destination fax device. The DDCR converts the received binary data back into fax data and transmits the fax data to the destination fax device thereby completing delivery of the fax data.

The SDCR includes a subscriber line interface apparatus to generate loop current, ring signals and call progress tones and signals for the originating fax device.
15 The SDCR is provided with a DTMF detector to capture dial information from the originating fax device and is provided with apparatus to receive modulated data signals from fax devices. The SDCR can include switching connection circuitry to facilitate bypass of the SDCR to permit pass through communications between the fax device and the public switched telephone network.
Brief Description of the Drawings Figure 1 is a functional block diagram of a preferred embodiment of the invention;

Figure 2 is a functional block diagram of th hardware components of the SDCR
25 device of Figure 1;

Figure 3 is a functional block diagram of the hardware components of the DDCR
device of Figure 1;

CA 022~4779 1998-11-18 Figure 4 is a flow chart depicting the process flow control for SDCR
communication with the Hub;

Figure 5 is a flow chart depicting the process flow control for Hub communication with an SDCR;

Figure 6 is a flow chart depicting the process flow control for DDCR
communication with the Hub or an SDCR;

Figure 7 is a flow chart depicting the process flow control for Hub communication with a DDCR.

Detailed Description of the rrerer,~l Embodiment Reference is made to Figure 1 which shows a functional block diagram of the hardware components of preferred embodiment of a facsimile communicationssystem of the present invention used to facilitate facsimile communications over a time delayed data path such as the Internet. In accordance with the invention, an originating fax device such as a fax machine 10 is connected to a source data conversion androuting device (SDCR) 12 by means of a line 14 which is a simple RJ11 connector style telephone wire. SDCR 12 interacts with originating fax machine 10 to capture thedestination fax machine dial info"~lion and fax data representative of the fax message in its entirety at SDCR 12. To facilitate interconnection with the Internet, SDCR 12 is interconnected to the public switched telephone network 16 over local IQOP 18.

SDCR 12 provides the call management signalling on line 14 to origi"aling fax machine 10 including provision of dial tone, loop current, ring signalling, receive fax tones, confirmation of facsimile messaging and all other necessary call management and call progress signalling as well as message management and mess~ge processing messaging between fax machine 10 and SDCR 12 to permit the originating fax machine 10 to deliver destination dialling information to SDCR 12 CA 022~4779 1998-11-18 , together with the actual data comprising the facsimile imaging which is to be transmitted.

Message headers are provided by SDCR 12 to enable carriage of the destination address and fax message data information over the communications link between SDCR 12 and Hub 24 through the Internet 20. The message headers define message formats and are provided for messages which include:

Table 1 1. A facsimile transmission header message 2. A message containing the destination dial number correspcnding to the destination fax machine 26; and 3. A message or messages containing a data stream corresponding to the facsimile message.

While the Internet can provide a data communications channel between two points interconnected on the Internet over a data path the time delay between the 15 two points i"lerconnected on the data path extending over the Internet varies. During times of network congestion the turn around delay can be several seconds.

Following receipt of a message from fax machine 10 SDCR 12 connects to fax Hub 24 over the Internet by dialling and interconnecting with an Internet Service Provider (ISP) 22. ISP 22 is preferably in the local serving area of the originating fax 20 machine but where \ha"anled or required may also be at a long distance (i.e. toll call) theref,om. Once connected to ISP 22 SDCR 12 obtains a data path over the Internet 20 to establish communication with fax Hub 24. The originating SDCR 12 communicates with fax Hub 24 to request and obtain fax routing information from fax Hub 24. The Hub provides routing information based on a database look up using 25 information identifying itself and the destination fax device phone number (Item 2 of Table 1) provided by SDCR 12. A translation from a destination phone number to an Inle",et IP address corresponding to a destination data conversion and routing device CA 022~4779 1998-11-18 (DDCR) 30 serving the destination fax 26 is obtained based on the result of the look up. It is preferable for the DDCR 30 to be located within the facilities of another Intemet Service Provider 28 that serves the local area where destination fax machine 26 is located to facilitate operation and maintenance of the DDCR. It will be 5 app~ci~ted that if there is no DDCR 30 in the local serving area of fax machine 26, any DDCR 30 can be used whereupon the public switched telephone network 32 can be used to deliver the fax from DDCR 30 to destination fax machine 26. Accordingly, the result of the Hub look up may be a message from Hub 24 to the SDCR 12 directing one of the following three outcomes, namely:

1. Send fax to DDCR 30;
2. Send fax to the Hub 24; and 3. Send fax out the PSTN.

In Case 1 of Table 2, the fax retained on SDCR 12 will be transferred directly to the DDCR 30 from the SDCR 12 over the Internet 20. With this outcome, no further communications between SDCR 12 and Hub 24 is necessary to support theIntemet communication between SDCR 12 and the target DDCR 30. Hub 24 provides SDCR 12 with the Internet address (IP) address of DDCR 30 and SDCR 12 uses this IP address to connect over the Internet to DDCR 30. This form of fax message delivery 20 may be referred to as direct connect delivery. With direct connect delivery, the data traffic between Hub 24 and the SDCR is reduced to routing messages for the fax message routing setup and termination. The actual data comprising the facsimile message itself will be delivered directly from SDCR 12 to DDCR 30 over the Internet 20.

In case 2 of Table 2, the subscriber SDCR 12 transfers the fax data to Hub 24 over the Internet 20. Once the complete message is received by Hub 24, Hub CA 022~4779 1998-11-18 24 will then relay this data to DDCR 30 over the Internet 20, when DDCR 30 becomes available to receive the message.

Once the fax messaging transfer over the Internet 20 to DDCR 30 is completed (i.e Case 1 - from SDCR 12, or Case 2 - Hub 24 of Table 2), DDCR 30 5 delivers the message received over the Internet 20 by dialling into the PSTN 32 to connect with the destination fax device 26. Upon connection to destination fax device 26, DDCR 30 will thereafter transfer the fax data to the destination fax machinewhereupon the fax message will have been delivered.

In case 3, the subsuiber SDCR 12 will bypass the Intemet altogether and 10 a direct connection over PSTN 16 will be established between SDCR 12 and destination fax machine 34. Upon connection to destination fax machine 34, SDCR 12 will thereafter transfer the fax data to the destination fax machine whereupon the fax message will have been delivered.

Communications between SDCR 12 and Hub 24 or DDCR 30 are 15 message based communications. The mess~ges are of a sufficient length to exchange data elements between the SDCR 12, Hub 24 and DDCR 30, however the message length is generally too short to carry data representing an entire fax message. A
plurality of messages is required to carry a fax message. Messages that are interchanged between SDCR 12 and Hub 24 include the following:

Table 3 RQM Route Request Message - Destination Number - Source Number RRM Route Response Message - Response - Type is one of - DDCR
- Hub CA 022~4779 1998-11-18 _ 9 _ - PSTN
- IP-Address - User-lD
- Password 5 DQM Disconnect RequestMessage - Reconnect - Time SDCR 12 will attempt to obtain routing instructions from Hub 24. In the event of an error condition, for example, if Hub 24 fails to provide a route response mess~ge (RRM) within a predetermined time limit from when the SDCR issues a Route 10 Request Message (RQM) (e.g. the Internet is down), SDCR 12 will use the PSTN 16 to directly connect to the target fax machine 34.

Referring to Figure 2, the components of SDCR 12 are shown in functional block diagram form. An originating fax machine 10 is connected to an input port 36 using a standard telephone wire 14 preferably using an RJ11 style connection jack. Output port 38 of SDCR 12 is connected to subscriber loop 18 of PSTN 16 preferably using an RJ11 style connector. SDCR 12 may have a prefix detect circuit 40 to monitor the tones received on input port 36 and to activate input control switch 42 to connect input port 36 directly to the output port 38 when a predetermined prefix selection digit has been detected on the input port 36 thereby placing SDCR 12 in 20 "bypass mode". When bypass mode is activated, switch 42 latches to the "C" or closed position thereby completing a bypass connection between input port 36 and output port .. .. .
38. In this manner, the SDCR acts to directly couple the originating fax machine 10 to the PSTN 16. Bypass mode al~ows direct fax communications between fax machines 10 and 34 interconnected by PSTN 16.

In any other mode than bypass mode, input control switch 42 is placed in the "O" position to interconnect input port 36 to telco simulator 44. Output control switch 46 is configured in the "C" position thereby interconnecting modem 48 to the input port 36 of the SDCR via the telco simulator 44. The modem 48 is a conventional fax and data modem and is capable of providing dual tone multi-frequency (DTMF) for CA 022~4779 1998-11-18 dialling into the PSTN. Telco simulator 44 includes DTMF detector circuits to capture and decode DTMF tones produced by the dialling equipment of outgoing originating fax machine 10. Also, modem 48 can produce and receive the fax data and perform message exchange with the originating fax device 10 to capture the fax produced by 5 the originating fax device. Fax capture is accGn,plished by communicating the fax data received at modem 48 to microprocessor 50. Microprocessor 50 includes volatile random access memory for storing the fax message as well as non-volatile random access memory for storing the control program operating microprocessor 50.

The control lines or paths existing bet,~veen the prefix detector 40, the telco simulator 44 and the modem 48 and microprocessor 50 are shown as dashed lines.
These control paths exist between these devices and microprocessor 50 to enable miuoprocessor 50 to monitor and control call and message exchange progress process within SDCR 20. Similarly, microprocessor 50 also controls the switch states of switches 42 and 46 by means of control lines (shown as dashed lines) extending 15 thereto from microprocessor 50. The telco simulator 44 is capable of providing dial tone and loop current to SDCR input port 36 to enable the originating fax machine 10 to "place a call" to convey a fax message to SDCR 12. The dialling sequence entered using the dialling equipment of fax machine 10 is detected by telco simulator 44 and the captured digits are provided to microprocessor 50. Telco simulator 44 also has 20 circuitry to produce ringing voltage for modem 48 to enable modem 48 to go off hook to receive an incoming call from fax machine 10.

Once all pages of a fax message have been received and stored in the memory associated with microprocessor 50, modem 48 is controlled by microprocessor 50 to acknowledge receipt of the fax message to the originating fax machine 10.
25 Microprocessor 50 activates output control switch 46 to latch into the "O" position thereby connecting modem 48 to the output port 38 of SDCR 12. In this switch configuration, modem 48 is then capable of placing an outbound call into PSTN 16. To deliver a fax message, a call is placed over PSTN 16. Modem 48 is first operated by miuo,l~rocessor 50 to interconnect with an Internet service provider 22 (of Figure 1) to CA 022~4779 1998-11-18 establish a connection to Hub 24 over the Internet data network, interconnecting the originaling Internet service provider 22 with Hub 24. In accordance with this connection process, the SDCR 12 will first establish communications with or "log-on to" ISP 22 to establish a communications link between SDCR 12 and ISP 22. Once the log-on 5 process has been completed, the microprocessor 50 of the SDCR will then perform the necessary steps to obtain an Internet data path connection to Hub 24. Once connected, a Route Reguest Mess~ge (RQM) is sent to Hub 24 to obtain the necessary routing information for the fax message which is now contained within the SDCR 12.
This information will be provided in a Route Response Message (RRM) described 10 previously and outlined in Table 3. The Route Request Message RQM contains a source fax telephone number and a destination fax telephone number to enable Hub24 to perform a d~t~h~se look up to obtain a routing information for routing the fax over the PSTN 16 or the Internet 20 depending on the relative locations of the originating fax machine and the destination fax machine. The Hub 24 will provide a Route 15 Response Message (RRM) to provide direction to SDCR 12 for fax message delivery.

Reference is made to Figure 3 which shows a functional block diagrarrl of the hardware configuration for a destination data conversion and routing device (DDCR) 30. A microprocessor 52 is in communication with a modem 54 which is adapted to be coupled to the public switch telephone network 32 over a subscriber line 20 56. The modem 54 is a conventional fax and data modem and is capable of originating calls into the PSTN 32 as well as providing fax protocol communications over the PSTN
to a destination fax machine (26 of Figure 1). Coupled to the microprocessor 52 is an ethernet adapter 58 which provides the hardware to support the necessary TCP/IP
communications between microprocessor 52 and the Internet network 20.

Figure 4 shows, in flow chart form, the process and decision flow of the process controlling the microprocessor 50 of the SDCR 12 device. The following description of the process flow depicted in Figure 4 refers also to Figure 2 which shows the apparatus of SDCR 12 that is controlled by the process. The idle watch loop of SDCR 12 is exemplified by decision boxes 60 and 66 where the SDCR microprocessor CA 022~4779 1998-11-18 loops between checking the status of input port 36 and output port 38 (see Figure 2) of the SDCR. If ringing voltage is detected on output port 38, the Y branch of decision box 60 is taken and, the process of connecting the input port 36 and output port 38 together is carried out as depicted by process box 62. To interconnect input port 36 5 to output port 38, input configuration switch 42 is placed into the "C" position. This mode or connection of SDCR 12 enables the SDCR to receive faxes from the public switched telephone network PSTN 16 transparently. The interconnection continues until an on hook condition is detected on input port 36 as shown in decision box 64.
The on hook condition indicates that the fax machine 10 (which in this case has 10 received a call or fax from the PSTN16) has gone into an on hook condition to signal the end of fax reception or the end of dealing with the incoming call.

The SDCR loop causes input port 36 to be repeatedly examined for an off hook condition indicating that fax machine 10 is in condition to place an outbound call as depicted by decision box 66. When off hook is detected, the Y path of decision 15 box 66 is taken and the DTMF tones received by telco simulator 44 are detected and compared, as shown in decision box 68, to determine if a prefix digit (such as the digit 9) is received. If a prefix digit is received (which indicates that the operator of the originating fax device wishes to place a direct call over the public switch telephone network for the PSTN 16), then the Y (yes) branch is taken from decision box 68 which 20 subsequently causes the SDCR to directly connect input port 36 to output port 38 as shown by process box 62. This configuration is the bypass mode where fax machine10 directly delivers a fax message over the PSTN 16.

If the digit received is not a prefix digit, then the N (no) branch of decision box 68 is taken, whereupon the telco simulator 44 captures the DTMF signalling 25 received from the originating fax machine 10 which indicates the telephone number of the target or destination fax device. This process is shown as process box 69. Once the destination dial number has been captured, telco simulator 44 is used to provide call progress tones (i.e. ring tone) to simulate a PSTN in placing an outbound call. Out bound control switch 46 is placed into the "C" position to interconnect modem 48 to CA 022~4779 1998-11-18 telco simulator 44, and then telco simulator 44 provides ringing voltage to modem 48 to simulate a telephone call received by Modem 48. Modem 48 answers the call andis then employed to capture the fax data and provide same to the microprocessor 50.
This process is shown in process box 70. Once the fax data has been captured and5 fax machine 10 goes on hook, microprocessor 50 configures the SDCR configuration switches 46 to couple the modem 48 to the PSTN 60 as depicted by process box 72.In this configuration, modem 48 is used to connect over PSTN 16 to ISP 22 and commence a log-on procedure to establish communications with ISP 22. Once the Internet service provider log-on process has completed, a data path connection is next made over the Internet 20 to fax Hub 24, whereupon the SDCR 12 provides a routing request message (RQM) to Hub 24 which announces the SDCR version and other identifying i"ror"~alion to Hub 24 together with a page count of the number of pages of fax data to be transmitted, as depicted by process box 74. The communications process between SDCR 12 and Hub 24 includes an exchange of messages to obtain 15 routing information from the Hub depicted by process box 76 and summarized in Table 3. Microprocessor 50 receives a Route Response Message (RRM) which originates from Hub 24 that contains routing directions to control routing of the fax message. The SDCR microprocessor compares the routing directions to determine if the fax message should be routed over the PSTN as depicted by reference boxes 78 thru 88.

Where the Route Response Message (RRM) contains PSTN routing directions the Y (yes) branch of decision box 78 is taken and the microprocessor 50 disconnects from ISP 22 and uses modem 48 to place a call over PSTN 16 to destination fax machine 34, as depicted by process box 80. A connection is made to the remote fax machine 34 which receives the fax data over the PSTN to thereby send the stored fax to the destination fax machine (34 of Figure 1) as depicted by process box 82.

If the Route Response Message (RRM) instructs routing of the fax message to the Hub 24 then the Y (yes) branch of decision box 84 is taken and SDCR carries out a process to forward the fax data to the Hub over the Internet 20 as depicted byprocess box 86.

CA 022~4779 1998-11-18 r lf the Route Response Message (RRM) contains instructions for the SDCR to route the message directly to a DDCR 30, then the Y (yes) branch of decision box 88 is taken and the SDCR disconnects from Hub 24 and connects over the Internet 20 to establish a communications with DDCR 30 which is identified by an Internet IP
5 address received in the Route Response Message (RRM) from Hub 24 as shown by process box 90. In connection with the process 90, it will be understood that the DDCR
30 is uniquely addressable by having an Internet Protocol (IP) address which allows communications between the SDCR 12 and the DDCR 30 to occur over the Internet 20.
Once a connection is established over the Internet 20, SDCR 12 will send the fax data 10 to the DDCR 30 as depicted by process box 92. Upon completion of the communications between the SDCR 12 and DDCR 30 over the Internet, the SDCR will initiate or will disconnect its data path from the DDCR as shown by process box 94.

Irrespective of how the routing of the fax message occurs, upon completion of interaction with Hub 24 and delivery of the fax message, SDCR 12 will 15 go on hook to the PSTN 16 to "hang up" the telephone call as shown in process box 96.
At this point SDCR 12 will be in idle mode again, looping through decision boxes 60 and 66, awaiting future events which will cause it to branch out to the other processes depicted in Figure 4.

Figure 5 shows, in flow chart form, the process which the Hub 24 follows 20 in communicating with an SDCR 12 device over the Internet 20. The following description includes references to reference numerals shown in Figure 1. Hub 24 awaits an Intemet session request by looping through an Internet IP request monitoring loop depicted by decision box 100 and the N branch of that decision box. When an IP
request is received, the Y branch of decision box 100 is followed and Hub 24 25 co""nences a process to create an IP session between Hub 24 and the remote SDCR
12 that is requesting a communications path; as depicted by process box 102.
Establishing a communications path requires the Hub processor to have operating, or to create, an application session to permit the remote SDCR 12 to obtain routinginformation from the fax Hub 24 as depicted by process box 104.
-CA 022~4779 1998-11-18 The Hub application session communicates with the SDCR to receive information identifying the originating SDCR and information identifying the facsimile message, for example, a fax page count, as depicted by process box 106. This information will be provided in a Routing Request Message (RQM) which is depicted 5 by process box 108. Receipt of a Routing Request Message (RQM) causes Hub 24 to look up routing information in its database based on the originating fax device telephone number (Originating Dial Number ODN)and the destination fax device telephone number (Destination Dial Number DDN), as depicted in process box 110.
If the database lookup provides a DDCR 30 corresponding to the destination fax device 10 telephone number (DDN) which is local to the originating fax machine 10, then the Y
branch of the decision box 112 is taken. The Y branch of decision box 112 causes the fax Hub 24 to issue a Routing Response Message (RRM) to the SDCR 12 directing SDCR 12 to route the fax message over the public switched telephone network 16 as shown by the process box 114 (i.e. outcome 3 of Table 2).

If the destination dial number (DDN) of the destination fax machine is not served by a DDCR 30, then outcome N of decision box 116 is taken and fax Hub 24 will issue a Route Response Message (RRM) directing the SDCR to route the fax messageover the PSTN (i.e. outcome 3 of Table 2) as depicted by process box 114.

If the outcome of the decision 116 is the Y branch, then that outcome 20 signifies that there is a DDCR 30 serving the calling area of the destination fax device 26, consequently, the routing of the fax message of the SDCR 12 will occur over the Internet 20. This will result in the Hub 24 issuing a Route Response Message (RRM) directing the SDCR to route the fax message over the Internet (i.e. outcomes 1 or 2 of Table 2). This Internet process handling is generally depicted by the process and 25 decision boxes contained within the outline frame 120 of Figure 5. To establish communications between the SDCR 12 and the target DDCR 30, the fax Hub has two options, namely to receive the fax from the SDCR 12, (queuing it for subsequent delivery to the DDCR 30, outcome 2 of Table 2), or to direct a direct delivery CA 022~4779 1998-11-18 ,.

connection between the SDCR 12 and the DDCR 30 over the Internet 20 (outcome 1 of Table 2).

For routing over the Internet 20, Hub 24 will check the status of each of the DDCR's that are in communication with the Hub 24. The status check will result in 5 a status determination as depicted by decision box 122 indicating whether or not the target DDCR is connected to the fax Hub 24. Where the target DDCR is connected to the fax Hub 24, the Y branch of decision box 122 is taken which then causes the fax Hub 24 to provide a routing message to the SDCR 12 directing it to route the faxmessage to be delivered to the target DDCR 30 directly as indicated by process box 124. Following provision of this routing message to the SDCR 12, the fax Hub 24 issues a Disconnect Request Message (DQM) to the target DDCR 30 requesting it todisconnect. The contents of this message are provided in Table 3 and include an estimated reconnect time which is calculated based on the number of pages that the SDCR indicated it wished to send to the target DDCR. This process is depicted byprocess box 126. DDCR 12 will indicate its receipt of the routing message by disconnecting the communications path over the Internet 20 to become available for receipt of a connection from SDCR 12. The reconnect time provided in the Disconnect Request Message (DQM) will be used by the DDCR in the error case where no SDCR
connection is completed following the DDCR disconnect from the Hub. When no SDCR20 connection is made within the time slot or window allotted in the reconnect time of the DQM message from the Hub, the DDCR will then reconnect to the Hub. This process and receipt of the DQM message is depicted by process box 128.

Where the DDCR is not connected to the fax Hub 24 the N branch of the decision box 122 is taken. The DDCR may not be connected to the fax Hub 24 for a25 number of reasons including:

- DDCR is busy, for example, processing a previous disconnection at the request of the fax Hub to receive a message from another SDCR, or - Internet outage, or CA 022~4779 1998-11-18 - DDCR outage.

In any event, when the target DDCR is not connected to the fax Hub 24 (i.e. in communication with over the Internet 20), the fax Hub 24 will then issue a Route Response Message (RRM) to the requesting SDCR 12 directing it to forward the faxmessage to the fax Hub 24 as depicted in process box 130. The SDCR will process this message and subsequently, will cause the fax data and routing information stored at the SDCR 12 to be communicated to the fax Hub 24 over the Internet 20 as depicted in process box 132. Upon complete receipt of the fax message from the SDCR 12, the fax Hub 24 will internally queue the SDCR file for subsequent transmission to the target DDCR 30. This is depicted in process box 134.

Figure 6 depicts, in flow chart form, the process controlling a DDCR. This process controls the communication over the Internet 20 with both the Hub 24 or an SDCR 12. The DDCR commences operation by connecting over the Internet 20 to the Hub 24 as shown by the process box 136. The DDCR then waits for messages received over the Intemet 20 as depicted by the DDCR traversing, or looping through, the decision boxes 138 and 146 and their respective N branch exits. When a message is received requesting delivery of a file to DDCR 30, as depicted by decision box 138 of Figure 6, the Y decision leg from box 138 is taken and the DDCR commences theprocess, depicted by process box 140, to receive the file from the Hub 24. Upon successful receipt of the file, including destination dial number information, DDCR 30 then disconnects from Hub 24, as shown by process box 142, and thereupon initiates a call into the PSTN 32 to deliver the received fax data to the destination fax machine 26, as depicted by process box 144. Once the fax message has been delivered, DDCR
30 reconnects to the fax Hub as depicted in process box 136.

If the outcome of the "is file" decision box 138 is the N (no) branch, then the DDCR examines the received message to determine if it is a disconnect request message as depicted in the decision box 146. If there is no disconnect request .

CA 022~4779 1998-11-18 message, then the DDCR continues in the message wait loop, shown by decision boxes 138 and 146, awaiting receipt of the next message over the Internet.

If DDCR 30 does receive a disconnect request message, then the Y
branch of decision box 146 is taken which causes DDCR 30 to disconnect from the 5 Hub as shown in process box 148. The disconnect from hub process, depicted by process box 148, is used to configure the DDCR to enable it to receive a connection from an SDCR and this process is followed only when the fax Hub has instructed the corresponding originating SDCR to deliver its fax data directly to the DDCR.

Following disconnection of the DDCR from the Hub, the DDCR enters a wait loop as depicted by decision boxes 150 and 149. In this loop, the DDCR checks for receipt of a connection over the Internet 20 from a source SDCR as depicted in decision box 150. If no connection has occurred, the N branch of the decision box is taken and DDCR next evaluates the elapsed time since disconnection from the Hub as shown by decision box 149. If the elapsed time is less than the reconnect time, 15 previously provided by the Hub in the Disconnect Request Message DQM), then the N branch of decision box 149 is taken to complete the loop. If the maximum elapsed time has been reached, the Y branch of decision box 149 is taken, and the DDCR
abandons waiting for an SDCR to connect by simply reconnecting to the Hub as shown by process box 136.

Upon successful connection by an SDCR over the Internet 20 to the DDCR, the Y exit of decision box 150 will be taken and the DDCR will then receive the fax data delivered to it over the Internet by the SDCR as depicted by process box 152.
Following receipt of the fax data from SDCR 12, DDCR 30 will then receive a disconnect from the SDCR 12 as depicted by process box 154. When the SDCR 12 disconnects from the DDCR 30, the DDCR will then initiate a call over the PSTN 32 to the destination fax device 26 as depicted by the process box 144.

CA 022~4779 1998-11-18 Figure 7 shows the decision flow chart for the Hub process which communicates with a DDCR. Hub 24 will receive over the Internet 20 a session request corresponding to a DDCR attempting to establish a communications link over the Intemet 20 extending between the DDCR and the Hub 24 as shown by the decision box 5 156. Where no such messages are received, the N branch of the decision box is taken causing the looping action of fax Hub 24 where it continues to monitor the Internet 20 for DDCR session requests.

When a session request is received, the Y branch of the decision 156 is taken which causes the fax Hub to create a session for communication with the DDCR
10 as depicted by process box 158. The Internet protocol (IP) session will then enable the fax Hub to communicate with the DDCR as depicted by process box 160. Informationregarding the DDCR session is then available to other processes operating on the fax Hub 24, to enable them to enquire as to the status of the DDCR corresponding to thi application session or to communicate with other Hub processes (e.g. the SDCR
15 process described with reference to Figure 5). The DDCR application process will check a queue on fax Hub 24 which corresponds to a DDCR 30 as shown by the decision box 162. If a message is found on the queue, the Y branch of decision box 162 is taken which causes the fax Hub 24 to send the queued file to the DDCR 30, as depicted by process box 164. Once the file has been transmitted to DDCR 30, the 20 DDCR will initiate a disconnect message which will be received by the fax Hub 24 (which corresponds to the process which the DDCR will follow when it in turn attempts to deliver the file over the PSTN 32 to the destination fax device 26 as described with reference to Figure 6). The process of receiving a disconnect message from the DDCR
30 is shown by process box 166.

Where there are no mess~ges in the queue for the DDCR corresponding to this process, the DDCR process will then check a wait receipt of disconnect message from the DDCR 30 as shown by decision box 168. If there is no disconnect messagethe fax Hub process will continue in the checking loop of decisions 162 and 168 until a fax message is queued for delivery, or a DDCR disconnect request is made.

CA 022~4779 1998-11-18 It will be apparent that many changes may be made to the illustrative embodiments, while falling within the scope of the invention and it is intended that all such changes be covered by the claims appended hereto.

Claims (11)

1. A facsimile communication system for facilitating facsimile communication over a time delayed communications channel comprising:
(a) source data conversion and routing (SDCR) means for coupling to an originating facsimile device and to a communications channel including:
(i) facsimile coupling means to communicate with an originating facsimile machine, (ii) network coupling means to communicate with said communications channel, (iii) computer means including storage means for controlling the operation of said SDCR to exchange data between said facsimile coupling means and said network coupling means to receive, store and transmit facsimile data between said originating facsimile machine and said communications channel, (b) destination data conversion and routing (DDCR) means for coupling to said communications channel and to the PSTN including:
(i) PSTN coupling means to communicate with a destination facsimile machine over the PSTN, (ii) network coupling means to communicate with said communications channel, (iii) computer means including storage means for controlling the operation of said DDCR to exchange data between said PSTN
coupling means and said network coupling means to receive, store and transmit facsimile data between said originating facsimile machine and said communications channel.

2. A communication system as claimed in claim 1 wherein said communications channel comprises the Internet.

3. A communication system as claimed in claim 1 further including a HUB in communication with said communications channel including:
(a) means to communicate with said SDCR over said communications channel, (b) means to communicate with said DDCR over said communications channel, (c) computer means including storage means for controlling the operation of said HUB to exchange message data communications with said SDCR and said DDCR.

4. A method for delivery of a facsimile message comprising:
(a) capturing the destination dial number to produce destination dial number data corresponding to a destination facsimile machine;
(b) capturing facsimile data corresponding to a facsimile image;
(c) producing a routing request message containing originating facsimile dial number data, destination facsimile dial number data;
(d) transmitting said routing request message over a data network;
(e) receiving a routing response message containing routing information selected from one of:
(i) routing over the PSTN; or (ii) routing over a data network to a specified network address, (f) processing said routing response message by:
(i) delivering said facsimile data over the PSTN to said destination dial number; or (ii) connecting to said specified network address and delivering said destination facsimile dial number data and said facsimile data to said network address.

5. A method as claimed in claim 4 wherein said data network comprises the Internet.

6. A method for delivery of a facsimile message comprising:
(a) connecting to a data network:
(b) receiving a message containing destination dial number data corresponding to a destination facsimile machine, and (c) for each message so received:
(i) receiving at least one message containing facsimile data corresponding to a facsimile image;
(ii) connecting to the PSTN;
(iii) providing dialling to said PSTN to direct a call to said destination facsimile machine;
(iv) establishing a facsimile communication over said PSTN;
(v) delivering said facsimile data thereover; and (vi) disconnecting from the PSTN.

7. A method as claimed in claim 6 wherein said data network comprises the Internet.

8. A method for delivery of a facsimile message over a time delayed data network comprising:
(a) capturing destination dial number data corresponding to a destination facsimile machine;
(b) capturing facsimile data corresponding to a facsimile image;
(c) producing a routing request message containing data representing an originating facsimile dial number and said destination dial number data;
(d) transmitting said routing request message over a data network;
(e) receiving a routing response message providing a specified network address;

(f) connecting to said specified network address and communicating said destination dial number data and facsimile data to said specified network address;
(g) connecting to the PSTN;
(h) providing dialling to said PSTN to direct a call to said destination facsimile machine;
(i) establishing a facsimile communication over said PSTN;
(j) delivering said facsimile data thereover; and (k) disconnecting from the PSTN.

9. A method as claimed in claim 8 wherein said data network comprises the Internet.

10. A method for delivery of a facsimile message over a time delayed data network comprising:
(a) capturing destination dial number data corresponding to a destination facsimile machine;
(b) capturing facsimile data corresponding to a facsimile image;
(c) producing a routing request message containing data representing an originating facsimile dial number and said destination dial number data;
(d) connecting over a data network to a predetermined network address (e) communicating said routing request message and said facsimile data to said predetermined network address;
(f) determining a destination network address depending upon said destination dial number;
(g) connecting over a data network to said destination network address and communicating said destination dial number data and said facsimile data thereto;
(h) connecting to the PSTN;

(i) providing dialling to said PSTN to direct a call to said destination facsimile machine;
a) establishing a facsimile communication over said PSTN;
(k) delivering said at facsimile data thereover; and (I) disconnecting from the PSTN.

11. A method as claimed in claim 10 wherein said data network comprises the Internet.