WO2001041396A1

WO2001041396A1 - Indirect data transmission

Info

Publication number: WO2001041396A1
Application number: PCT/GB2000/004559
Authority: WO
Inventors: Jeremy David William Frederick Sharples; William Richard Mead
Original assignee: British Telecommunications Public Limited Company
Priority date: 1999-11-29
Filing date: 2000-11-29
Publication date: 2001-06-07
Also published as: GB2361605A; GB9928170D0; GB0029150D0; GB2361605B

Abstract

In an indirect data transmission system a store and forward apparatus to receive data from a mobile station (3) which stores and forwards data received via a mobile telephone network (4) from a mobile station (1). When all the data in a message has been received by the store and forward apparatus (3), it forwards the message to its ultimate destination by a non-mobile network (5). The mobile station (1) can reconnect to the store and forward apparatus (3), if the connection is lost during transmission of a message.

Description

Indirect Data Transmission

Description

The present invention relates to the indirect transmission of data.

It is known to send data, including computer files and faxes, via mobile telephone networks and, indeed, GSM (Global System for Mobile communications) makes provision for the provision of such data without the use of audio modems at mobile stations. However, the quality of the path to a base transceiver station varies with the position of a mobile station. This can result in a connection being lost if the mobile station is moving when the quality of the path to the base transceiver station falls below a useable level, and the consequent need to restart the whole transmission.

The present invention addresses this problem.

A system according to the present invention uses a store and forward apparatus to receive data from a mobile station and, when all the data in a message has been received, forward the message to its ultimate destination by a non- mobile network. The mobile station may reconnect to the store and forward apparatus, if the connection is lost during transmission of the message.

Since the mobile terminal and the store and forward apparatus may be made or operated by different persons and may be located in different jurisdictions, protection is sought for these elements independently.

According to the present invention, there is provided a method of transmitting data, the method comprising: - combining a destination ID, e.g. a telephone number or an e-mail address, and further data in a computer file; dividing said file into a plurality of chunks; and transmitting the chunks via a mobile communication network, e.g. a cellular mobile telephone network, to a store and forward apparatus having a direct connection to a non- mobile communication network, e.g. the PSTN or the Internet. The mobile communication network need not be a GSM network.

If circumstances so demand, the method may be such that transmitting the chunks comprises detecting a loss of connection to the store and forward apparatus, re-establishing the connection with the store and forward apparatus and retransmitting a chunk whose transmission was interrupted by said loss of connection.

The further data comprises an image file, in which case, the method includes scanning a document to produce said image file and may include accepting user input of said destination ID to provide a spoofed fax service. Preferably, combining said destination ID and said further data comprises compressing and combining, e.g. by zipping, a file containing the destination ID and said image file into a single archive file.

The method may be performed advantageously on a vehicle. However, the method may also be performed for a person walking.

It has been found that optimum performance is achieved by careful selection of the size of the first to the penultimate chunks. In the case of a GSM network, 32Kbyte data chunks, equivalent to 30 seconds of connection time, have been found to be optimal for transmission from trains, although connections times of 20 to 40 seconds would give reasonable performance. However, the chunk size may be varied dynamically, reducing the chunk size if the chunk transmission failure rate rises and vice versa.

According to the present invention, there is provided a technical embodiment of software suitable for controlling an apparatus, wherein the software comprises instructions for: - combining a destination ID and further data in a computer file; dividing said file into a plurality of chunks; and controlling a mobile station for the transmission of the chunks via a mobile communication network to a store and forward apparatus having a direct connection to a non- mobile communication network. A technical embodiment of software is one adapted for controlling an apparatus, e.g. object code on a data carrier or carried by a signal, in RAM or ROM, or on a disk in a computer.

Preferably, the instructions for transmitting the chunks comprises instructions for detecting a loss of connection to the store and forward apparatus, and instructions for controlling the mobile station to re-establish the connection with the store and forward apparatus and for retransmitting a chunk whose transmission was interrupted by said loss of connection.

The further data comprises an image file, in which case, the instructions include calls to a document scanner driver to produce said image file and instructions for controlling acceptance of user input of said telephone number to provide a spoofed fax service. Preferably, combining said telephone number and said further data comprises compressing and combining, e.g. by zipping, a file containing the telephone number and said image file into a single archive file.

Preferably, the instructions are such that the first to the penultimate chunks are each transmitted in the same time, said time being in the range 20 to 40 seconds. More preferably, the instructions are such that said time is about 30 seconds.

According to the present invention, there is provided a method of effecting data communication comprising: - receiving a plurality of chunks of data from a mobile communication network; assembling data in the chunks to form a single file; extracting a telephone number from said file; and transmitting data remaining in the file via a non- mobile communication network to a subscriber apparatus identified by said telephone number.

Preferably, said remaining data comprises an image file. More preferably, said image file is transmitted as a facsimile signal. Still more preferably, said single file is a compressed archive file containing a text file, holding said telephone number, and an other file.

According to the present invention, there is provided a technical embodiment of software suitable for controlling an apparatus, wherein the software comprises instructions for: - controlling the reception of a plurality of chunks of data from a mobile communication network; assembling data in the chunks to form a single file; extracting a destination ID from said file; and controlling the transmission of data remaining in the file via a non- mobile communication network to a destination identified by said destination ID.

According to the present invention, there is provided a data transmission apparatus comprising: - processing means for combining a destination ID and further data in a computer file and for dividing said file into a plurality of chunks; and transmission means for transmitting the chunks via a mobile communication network to a store and forward apparatus having a direct connection to a non-mobile communication networ

Preferably, the transmission means includes means for detecting a loss of connection to the store and forward apparatus, re-establishing the connection with the store and forward apparatus and retransmitting a chunk whose transmission was interrupted by said loss of connection.

Preferably, the further data comprises an image file. More preferably, a document scanner is included for scanning a document to produce said image file. Still more preferably, a keypad is included for user input of said telephone number.

Preferably, the processing means is configured for combining said telephone number and said further data by compressing and combining, e.g. by zipping, a file containing the telephone number and said image file into a single archive file. Preferably, the first to the penultimate chunks, produced by the processing means from said single file, are all the same <ize and said size being such that the time required for the transmission of each chunk by the transmission means is in the range 20 to 40 seconds. More preferably, said time is about 30 seconds.

Preferably, the transmission means comprises a cellular telephone network mobile station.

The apparatus may be mounted in or on a vehicle.

According to the present invention, there is provided an apparatus for effecting data communication comprising: - receiving means for receiving a plurality of chunks of data from a mobile communication network; processing means configured for assembling data in the chunks to form a single file and extracting a destination ID from said file; and transmission means for transmitting data remaining in the file via a non-mobile communication network to a destination identified by said destination ID.

Preferably, said remaining data comprises an image file. More preferably, the transmission means is configured such that said image file is transmitted as a facsimile signal.

Preferably, the processing means is configured for extracting and decompressing a text file, holding said telephone number, and an other file from said single file, said single file being an archive file.

An embodiment of the present invention will now be described by way of example, with reference to the accompanying drawings, in which: -

Figure 1 is a diagram of a system embodying the present invention;

Figure 2 shows a facsimile transmission terminal for use in the system shown in Figure 1;

Figure 3 is a diagram illustrating the operation of the terminal of Figure 2; and Figure 4 is a diagram illustrating the operation of the server of Figure 1. Referring to Figure 1, a facsimile transmission terminal 1 is mounted on a train 2. The terminal can communicate with a store and forward server station 3 via a cellular mobile telephone network 4 and the pstn 5. Additionally, the server station 3 can communicate with a conventional fax machine 6 via the pstn 5. The server station 3 comprises a conventional personal computer, running Windows NT as an operating system, with an internal fax modem.

Referring to Figure 2, the facsimile transmission terminal 1 comprises a laptop personal computer 11 running Microsoft Windows 95 as an operating system. A keypad 12 is plugged into an external keyboard port on the computer 11. A scanner 13 is connected to the computer's parallel port. Finally, the computer 11 has a GSM modem PCMCIA (Personal Computer Memory Card International Association) card (not shown) which is connected to a GSM mobile station 14. It is desirable that the computer's own keyboard and the GSM mobile station 14 be hidden from view to prevent misuse of the terminal 1 by the public.

The process of transmitting image data from the facsimile transmission terminal 1 to the server 3 will now be described.

Referring to Figure 3, the computer 11 runs a input process 21 which causes it to display, on its screen 11a, an invitation to send a fax and telling a prospective user to press an "ENTER" key on the keypad 12 to initiate fax transmission. When a user presses the "ENTER" key, the input process invites the user to enter the telephone number of the destination fax machine using the keypad 12. The user enters this number and then presses the "ENTER" key again. The user interface of a TWAIN driver 22 then invites the user to place the document to be scanned on the scanner. The user then scans in the document to be sent. Each page of the scanned document is stored as a bitmap image file 23 containing a monochrome image of the document and a page order identifier. The telephone number is stored in a text file.

On completion of the scanning, the input process redisplays the telephone number input screen and calls procedures 25 of an archiving library to compress the text file containing the number and the bitmap image files and combine them in an archive file 26. In this example, the archiving library is provided by PKWare and the archive file 26 is a "zip" file.

The zip archive file 26 is then stored in a buffer directory. A transmission process 27 repeatedly inspects the buffer directory for new archive files. When a new archive file 26 is found in the buffer directory, the transmission process splits it into 32KByte chunks (the last chunk will usually contain less than 32Kbytes) and creates a communication control file 28 identifying all of the chunks. An ID, unique to the image to be transmitted, and a chunk serial number are then added to each chunk by the transmission process 27. In the present example, the naming of these files is as follows: - communication control file

FM facsimile transmission terminal ID Xiinique ID >.bat archive file

FM <facsimile transmission terminal ID Xiinique ID >.zip.

Once the archive file 26 has been spilt into chunks, the transmission process 27 instructs the GSM mobile station 14 to place a data call to the server 3 via the cellular mobile telephone network 4 and the pstn 5. The transmission process then establishes an FTP connection to the server 2.

When the FTP connection has been established, the transmission process 27 first sends the communication control file 28, which will be quite small, and then begins to send the chunks sequentially to the server 3. Should the connection to the server 3 fail, typically as a result of losing GSM coverage, the transmission process redials the server's telephone number until the connection can be re-established and then starts sending the chunks again, starting with the chunk that was interrupted.

On completing the transmission of the chunks, the transmission process 27 sends a "file size request" message to the server 3 and the server 3 replies with the number of file bytes received. The transmission process 27 compares this with the size of the files sent. If there is agreement the archive file 26 and the communication control file 28 are deleted or archived. If there is not agreement, the transmission is repeated.

Referring to Figure 4, at the server 3, the received communication control file 28 and the received chunks 31 are stored initially in a receive directory 32 by a receive process 34. When the "file size request" message 33 is received, the receive process 34 determines the number of file bytes received and sends this number back to the facsimile transmission terminal 1 in a "byte number" message 35. The receive process 34 is implemented using Mcrosoft Internet Information Service (IIS) software.

A reassembly process 36 periodically scans the receive directory for communication control files 28. If a communication control file 28 is located, the reassembly process checks whether it has been processed by reading a "processed" flag.

If an unprocessed communication control file 28 is located, the reassembly process 36 opens it. Its contents identify all the chunks 31 that should have been received and placed in the receive directory 32. If all of the chunks 31 are found in the receive directory, they are reassembled by the reassembly process 36 into a copy 37 of the original archive file 26. The chunks 31 and the communication control file 28 are then either deleted or archived by the receive process 34.

The copy archive file 37 is then placed in a queue until the fax processing resources become available. Once the fax processing resources become available, which may be immediately, the reassembly process 36 calls a procedure of a library 38, in this example provided by PKWare, which decompresses and extracts the contents of the copy archive file 37 into a particular directory 39, creating a text file 42 containing the destination telephone number and one or more bitmap image files 43, and then writes a "ready" flag to the directory 39 containing them.

The transmission of the fax to its final destination is effected by a Microsoft VBA (Visual Basic for Applications) program 40 in conjunction with Microsoft Word 41. The VBA program 40 detects the "ready" flag in the directory 39 and inserts the bitmap image file or files 43, ;n the order specified therein, into respective pages of a Word document as embedded objects. The VBA program 40 then "prints" the new Word document via a Zetafax fax printer driver. The VBA program 40 reads the destination telephone number from the text file 42 and uses DDE (Dynamic Data Exchange) to pass the telephone number to Zetafax fax server software 44.

The Zetafax fax server software 44 then functions in its normal manner to send the Word document as a fax to the fax machine 5 identified by the number read from the text file. When the Word document has been successfully sent, the VBA program 40 deletes the text and image files 42, 43, or archives them, and sets the directory's 39 ready flag to false.

The operator of the server 3 has control of any cover sheets that are sent with the image and may use the cover sheet for advertising.

It will be appreciated that the server processing could be performed by alternative software, for example bespoke programs or different combinations of commercially available packages.

It will be appreciated that many modifications may be made to the embodiment described above. For instance, the server may send the received data as an e-mail or by FTP.

Claims

1. A method of transmitting data, the method comprising the steps of : - combining a destination identifier in character-coded form and further data to form a computer file; dividing said computer file into a plurality of chunks; and transmitting the chunks as circuit switched signals via circuit switched mobile communication network connections to a store and forward apparatus which has a direct connection to a non- mobile communication network.

2. A method according to claim 1, wherein the step of transmitting the chunks includes the detection of a loss of connection to the store and forward apparatus, reestablishing the connection with the store and forward apparatus and retransmitting a chunk whose transmission was interrupted by said loss of connection.

3. A method according to claim 1 or 2, wherein the further data comprises an image file.

4. A method according to claim 3, including the step of scanning a document to produce said image file.

5. A method accordmg to claim 4, including accepting user input of said destination identifier.

6. A method according to claim 5, wherein the step of combining said destination identifier and said further data comprises compressing and combining a file containing the destination identifier and said image file into a single archive file.

7. A method according to any preceding claim, wherein the steps of combining, dividing and transmitting are carried out on or in a vehicle.

8. A method according to any preceding claim, wherein the first to the penultimate chunks are all the same size and are each transmitted in a time slot of the same duration, said duration being in the range 20 to 40 seconds.

9. A method according to claim 8, wherein said duration is about 30 seconds.

10. A technical embodiment of software suitable for controlling an apparatus, wherein the software comprises instructions for: - combining a destination identifier in character-coded form and further data in a computer file; dividing said file into a plurality of chunks; and controlling a mobile station for the transmission of the chunks as circuit switched signals via circuit switched mobile communication network connections to a store and forward apparatus which has a direct connection to a non- mobile communication network

11. A technical embodiment of software according to claim 10, wherein the instructions for transmitting the chunks comprises instructions for detecting a loss of connection to the store and forward apparatus, and instructions for controlling the mobile station to re-establish the connection with the store and forward apparatus and for retransmitting a chunk whose transmission was interrupted by said loss of connection.

12. A technical embodiment of software according to claim 10 or 11, wherein the further data comprises an rmage file.

13. A technical embodiment of software according to claim 12, including instructions for calling a procedure of a driver for a scanner for scanning a document to produce said image file.

14. A technical embodiment of software according to claim 13, including instructions for controlling the acceptance of user input of said destination identifier.

15. A technical embodiment of software according to claim 14, including data compression and archiving instructions for compressing and combining a file containing the destination identifier and said image file into a single archive file.

16. A technical embodiment of software according to any one of claims 10 to 16, wherein the instructions are such that the first to the penultimate chunks are each transmitted in time slots having the same duration, said duration being in the range 20 to 40 seconds.

17. A technical embodiment of software according to claim 16, wherein the instructions are such that said duration is about 30 seconds.

18. A method of effecting data communication comprising the steps of: - receiving a plurality of chunks of data, in the form of circuit switched signals, from circuit switched mobile communication network connections; assembling data in the chunks to form a single file; extracting a character-coded destination identifier from said file; and transmitting data remaining in the file via a non- mobile communication network to a destination identified by said destination identifier.

19. A method according to claim 18, wherein said remaining data comprises an image file.

20. A method according to claim 19, wherein said image file is transmitted as a facsimile signal.

21. A method according to any one of claims 18 to 20, wherein said single file is a compressed archive file containing a text file, holding said destination identifier, and another file.

22. A technical embodiment of software suitable for controlling an apparatus, wherein the software comprises instructions for: - controlling the reception of a plurality of chunks of data, in the form of circuit switched signals, from circuit switched mobile communication network connections; assembling data in the chunks to form a single file; extracting a character-coded destination identifier from said file; and controlling the transmission of data remaining in the file via a non- mobile communication network to a destination identified by said destination identifier.

23. A technical embodiment of software according to claim 22, wherein said remaining data comprises an image file.

24. A technical embodiment of software according to claim 23, wherein said image file is transmitted as a facsimile signal.

25. A technical embodiment of software according to any one of claims 22 to 24, wherein said single file is a compressed archive file containing a text file, holding said destination identifier, and another file.

26. A method according to anyone of claims 1 to 9 in combination with a method according to an one of claims 18 to 22.

27. A data transmission apparatus comprising: - processing means to combine a destination identifier in character-coded form and further data in a computer file and to divide said file into a plurality of chunks; and transmission means to transmit the chunks as circuit switched signals via circuit switched mobile communication network connections to a store and forward apparatus having a direct connection to a non- mobile communication network

28. An apparatus according to claim 27, wherein the transmission means includes means to detect a loss of connection to the store and forward apparatus, to re-establish the connection with the store and forward apparatus and to re-transmit a chunk whose transmission was interrupted by said loss of connection.

29. An apparatus according to claim 27 or 28, wherein the further data comprises an image file.

30. An apparatus according to claim 28, including a document scanner for scanning a document to produce said image file.

31. An apparatus according to claim 30, including a keypad for user input of said destination identifier.

32. An apparatus according to claim 31, wherein the processing means is configured to combine the destination identifier and the further data by compressing and combining a file containing the destination identifier and the image file into a single archive file.

33. An apparatus according to an one of claims 27 to 32, wherein the first to the penultimate chunks, produced by the processing means from said single file, are all the same size, the size being such that the time required for the transmission of each chunk by the transmission means is in the range 20 to 40 seconds.

34. An apparatus according to claim 33, wherein said time is about 30 seconds.

35. An apparatus according to any one of claims 27 to 34, wherein the transmission means comprises a cellular mobile telephone network mobile station.

36. A vehicle including an apparatus according to any one of claims 27 to 35.

37. An apparatus for effecting data communication comprising: - receiving means to receive a plurality of chunks of data, in the form of ciruit swithed signals, from circuit switched mobile communication network connections; processing means configured to assemble data in the chunks to form a single file and to extract a character-coded destination identifier from said file; and transmission means for transmitting data remaining in the file via a non- mobile communication network to a destination identified by said destination identifier.

38. An apparatus according to claim 37, wherein said remaining data comprises an image file.

39. An apparatus according to claim 38, wherein the transmission means is configured such that said image file is transmitted as a facsimile signal.

40. An apparatus according to claim 37, 38 or 39, wherein the processing means is configured to extract and decompress a text file to hold said destination identifier, and another file from said single file, said single file being an archive file.