GB2360174A

GB2360174A - Transmitting compressed messages to units identified as supporting compression

Info

Publication number: GB2360174A
Application number: GB0005690A
Authority: GB
Inventors: Erik Sparre; Kristoffer Aberg
Original assignee: Telefonaktiebolaget LM Ericsson AB
Current assignee: Telefonaktiebolaget LM Ericsson AB
Priority date: 2000-03-09
Filing date: 2000-03-09
Publication date: 2001-09-12
Anticipated expiration: 2020-03-09
Also published as: GB2360174B; GB0005690D0

Abstract

A communications device such as a mobile phone detects when a received SMS message is compressed. The numbers of the senders of compressed messages are stored, and, when a user of the device wishes to send an SMS message to one of the stored numbers, it is recognised that compression can be used. Recognition of a mobile phone's compression support may be performed at the message centre, in which case, the message would be concatenated into more than one uncompressed message if the destination phone did not support compression, otherwise the message would be sent in a compressed format.

Description

2360174

COMMUNICATIONS SYSTEM FIELD OF THE INVENTION

This invention relates to a communications system, and in particular to a short messaging system (SMS) which is available in wireless telecommunications networks. BACKGROUND OF THE INVENTION

The short messaging system (SMS) allows a subscriber to a wireless telecommunications network, for example GSM, to send short text messages to other subscribers. An advantage of the SMS system is that the messages are sent on a control channel of the system, which means that it is not necessary to set up a call to transmit a message. The short messages are typically made up only of alphanumeric characters entered through a keypad of a phone. The system imposes a limit, for example corresponding to 140 bytes or 160 characters, on the amount of data which can be contained in each short message.

Recently, compression of SMS messages has been introduced. This is described in GSM standard 03.42. This allows longer messages to be sent, while remaining within the maximum permissible amount of data.

W099/04553 describes one way of using compression of SMS messages to allow images to be sent.

If both the sending and receiving devices support SMS compression, a larger number of characters can be sent within the maximum available data length.

However, a user, wishing to send a message, may not know whether the intended receiving device supports SMS compression. Moreover, since relatively few users could be expected to know details of SMS compression, it would be preferable for the user not to be asked whether an outgoing message should be compressed. SUMKARY OF THE INVENTION The invention therefore provides a system whereby a user can take advantage of compression to send longer text messages than are conventionally available, without needing to know anything about compression, and in particular without needing to know whether a receiving device supports compression.

The invention is applicable to SMS messages, or to similar message systems, in particular to text message systems with restricted message lengths. For example, the invention is applicable also to any system allowing email, text, or other short messages to be sent over a communications network.

In accordance with a preferred aspect of the invention, a mobile phone or other terminal device determines whether each incoming text message is compressed. The caller identifier of each other device, from which a compressed message has been received, is then stored. When a user of the mobile phone or other terminal device then wishes to send an outgoing text message to that other device, it is known that the other device supports compression, and so compression can be used for the outgoing message.

Preferably, the user of the mobile phone or other terminal device is informed that compression can be used for the outgoing message. This allows the user to take advantage of the possibility of sending a longer message than would otherwise be possible.

The invention is described with specific reference to SMS messages sent in a GSM system. However, it is also applicable to other similar messaging systems in other telecommunications systems. Moreover, although the preferred embodiments of the invention describe storing telephone numbers associated with incoming messages, other caller identifiers can be used. For example, incoming messages can -be received from email identities, WAP addresses, or IP addresses, and an indication as to whether a device supports compression can be stored in association with each such identifier.

BRIEF DESCRIPTION OF DRAWINGS

Figure 1 is a block schematic diagram of a mobile phone in accordance with the invention.

Figure 2 is a flow chart illustrating one aspect of the invention.

Figure 3 is a flow chart illustrating another aspect of the invention.

Figure 4 is a flow chart illustrating another aspect of the invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Figure 1 is a schematic representation of a mobile phone in accordance with the invention. The phone is under the control of a processor 10, which cooperates with a memory 11 to provide the usual phone functions. In addition, the phone supports SMS messaging in a conventional way, except as described herein. The processor receives inputs from the user by means of a keypad 12, and controls messages sent to the user via a display 13. The processor 10 and memory 11 communicate with radio transceiver circuitry 14 and an antenna 15, for sending and receipt of signals over an air interface.

The invention is described herein primarily with reference to the short messaging system (SMS0) in GSM. However, the invention is also applicable to any similar text messaging system, for example email, and is also applicable to other types of networks, for example iDEN.

Figure 2 is a flow chart which shows the operat-ion within the mobile phone of a method in accordance with the invention.

In step 20, it is determined that the phone has received a SMS message. In step 21, it is determined whether the received message has been compressed.

If it is determined in step 21 that the message has not been compressed, the method proceeds to step 22, in which the message is presented to the user in a conventional way, and to step 23, where the method ends.

is By contrast, if it is determined in step 21 that the message has been compressed, the method proceeds to steQ 24. In step 24, the Calling Line Identifier (CLI) of the calling party, that is, the telephone number of the caller by whom the received message was sent, is examined, and it is determined whether that CLI is already in a "compression list". If it is already in that list, no further action need be taken, and the method proceeds to step 22, and to step 23, as previously described.

If it is determined in step 24 that that CLI is not already in a "compression list", the method proceeds to step 25, in which the CLI is stored in the -compression list". This may for example be a list of telephone numbers which, it has been specifically determined, use compression for SMS messages. Alternatively, the phone may already store a list of telephone numbers, for example the user's phone book, and the "compression list" may then be a subset of the existing list, which have been specifically flagged as using compression for SMS messages.

Figure 3 is a flow chart illustrating the method of the invention in sending a SMS message.

In step 30, it is determined that the user has indicated that an SMS message is to be sent. This can be entirely conventional.

In step 31, the phone receives the message t-ext, entered by the user via the key_pad, for example.

is Again, this is conventional, and other ways of entering messages are of course possible.

In step 32, the phone receives the number to which the message is to be sent, which may for example be entered by the user via the keypad, or selected by the user from a stored phone book. Again, this is conventional.

In step 33, the phone compares the entered number with the numbers stored in the "compression list". if there is no match, the method proceeds to step 34, in which the message is sent. For example, the message may be sent normally, that is, without compression.

If in step 33 a match is found, that is, the entered number is one which is stored in the "compression list", the method proceeds to step 35, in which the user is notified of the fact. For example, the user may be informed (by means of text or symbols in the display, or by an audible indication) that it is possible to send a longer message. The user can also be informed how many characters he is allowed to send in a message. The user can then take that opportunity to add text to the previously entered message, to take advantage of the increased available length, before pressing a key to send the message, at which point the method again proceeds to step 34, in which the message is sent. In this case, the message may be sent compressed.

Figure 4 is a flow chart illustrating an alternative method of the invention in sending a SMS message.

In step 40, it is determined that the user has indicated that an SMS message is to be sent. This can be entirely conventional.

In step 41, the phone receives the number to which the message is to be sent, which may for example be entered by the user via the keypad, or selected by the user from a stored phone book. Again, this is conventional.

In step 42, the phone compares the entered number with the numbers stored in the "compression list" If in step 42 a match is found, that is, the entered number is one which is stored in the "compression list", the method proceeds to step 43, in which the user is notified of the fact. For example, the user may be informed (by means of text or symbols in the display, or by an audible indication) that it is possible to send a longer message than usual. The user can also be informed how many characters he is allowed to send in a message.

After step 43, or directly after step 42 if that step finds no match, the method proceeds to step 44, in which the phone receives the message text, entered by the user via the keypad, for example. Again, this is conventional. and other ways of entering messages are of course possible.

Then, in step 45, the message is sent, either without compression, if compression is not supported by the receiver, or with compression, if that is possible.

It should be noted, however, that, in some cases, compression is of little benefit. For example, if an entered message is 300 bytes long, it could only be sent by splitting it into two separate messages, each of up to 140 bytes or 160 characters (the maximum available length). However, if the message could only be compressed to 170 bytes, then even the compressed message would need to be split into two separate messages, since the compressed length is greater than the maximum available length for a single message. In such a case, the message may not be sent compressed, even when the receiving terminal supports compression.

is The process of splitting a single message into two or more parts for transmission over the network, with these parts being put back together at the receiver, is called concatenation.

Different embodiments of the invention can provide different degrees of transparency, as required. That is, the user may be made more or less aware of the principles of compression. For example, when it is determined that a compressed message can be sent, the phone may not provide any indication to the user, but may simply accept the longer message, in which case the user may or may not even notice that compression is used. Alternatively, the user may be informed that compression is to be used, for example to allow the possibility of sending longer messages. Still further, the user may be asked whether he wishes compression to be used.

The invention is described above with reference to a situation in which a user wishes to send a message to a single recipient. However, it is also desirable that the same advantages be obtained when the message is to be sent to a list of multiple recipients. In that case, the testing procedure can be carried out in respect of each recipient. If it is determined that each recipient supports compression, then a longer message can be permitted to be input.

An alternative use of the invention is that, before entering the text of a message, the user can do a pre-check in his list. An entered number is compared with the numbers in the stored "compression list", and the user can be informed whether a particular number has been logged as being capable of receiving compressed messages. As above, this can be implemented with different degrees of transparency. For example, the user may be informed explicitly that compression is to be used, or may simply be informed that it is possible to send a longer message, without further explanation.

The invention is described above with reference to SMS messages, specifically in the GSM cellular phone system. However, it will be appreciated that the invention can be practised in any communications system in which short messages can be sent.

The invention as described so far relates to functions carried out in a mobile device or other terminal. Support for improved use of compression and/or concatenation can also be provided in a network.

Figure 5 shows schematically a network in which a user of a first mobile station 50 wishes to send a short message to a user of a second mobile station 52. As before, the short message may be an SMS message in a GSM system, but could equally be any other type of short message. The message is sent over the air interface to a base station 54, and then to a mobile switching centre (MSC) 56, and a base station 58 serving a cell in which the second mobile station is located, and then over an air interface to the second mobile station 52.

In this embodiment of the invention, if the first mobile station 50 supports compression, the short message is always sent compressed over the air interface to the base station 54. A server within the network, for example in the MSC 56, then determines whether the recipient (or each recipient, if the message is to be sent to a list of recipients) supports compression. If so, the message is forwarded in compressed form to the second mobile station 52. However, if the second mobile station 52 does not support compression, the message is forwarded in uncompressed form to the second mobile station 52. If necessary, because the uncompressed message is longer than the maximum message length, the message can be concatenated, that is, split into two or more parts for onward transmission, and then optionally put back together by the receiver, if the receiver supports concatenation. This minimises network traffic, while ensuring that compressed messages are not sent to terminals which do not support compression.

There is thus described method and apparatus which allow a user to obtain the benefit of message compression, without having to understand the details thereof.

Claims

1 A method of handling an incoming message, the method comprising:

detecting an identifier relating to a sender of the incoming message; determining whether the incoming message is compressed; and if the incoming message is compressed, storing the identifier relating to the sender thereof, together with an indication that said sender supports message com-cression.

2. A method as claimed in claim 1, comprising storing a list of identifiers relating to respective senders, together with an indication that each of said senders supports message compression.

3. A method as claimed in claim 1, wherein the step of storing the identifier relating to the sender, together with an indication that said sender supports message compression, comprises storing a flag in association with said identifier in an existing list of identifiers.

4. A method as claimed in claim 3, wherein the identifiers are telephone numbers.

5. A method as claimed in claim 1, wherein the step of storing the identifier relating to the sender, together with an indication that said sender supports message compression, comprises adding said identifier to a list of identifiers relating to respective senders, each of which supports message compression.

6. A method as claimed in claim 1, wherein the identifier relating to the sender of the incoming message is the Calling Line Identifier (CLI) thereof.

7. A method of transmitting an outgoing short messace, the method comprising:

detecting an input identifier relating to an 11- is intended recipient of the outgoing message; comparing said input identifier with stored identifiers relating to recipients which support message compression; and if said input identifier is a stored identifier relating to a recipient which supports message compression, transmitting said message in compressed form.

8. comprising:

A method as claimed in claim 7, further before transmitting said message, indicating an available message length to a user.

9. A method as claimed in claim 8, wherein the step of indicating an available message length comprises providing a visual indication to the user.

10. A method as claimed in claim 9, wherein the step of providing a visual indication to the user ' comprises providing a visual indication of an available message length in characters.

11. A method as claimed in claim 9, wherein the step of providing a visual indication to the user comprises providing a visual indication that an increased message length is available.

12. A method as claimed in claim 8, wherein the step of indicating an available message length comprises providing an audible indication to the user.

13. A method as claimed in claim 7, further comprising:

if said input identifier is a stored identifier relating to a recipient which supports message compression, allowing input of a message of a length which can be transmitted only with compression.

14. A method of transmitting an outgoing short message to a plurality of intended recipients, the method comprising:

detecting a respective input identifier relating to each intended recipient of the outgoing message; comparing each of said input identifiers with stored identifiers relating to recipients which support message compression; and if each of said -Input identifiers is a stored identifier relating to a recipient which supports message compression, transmitting said message in compressed form.

is. A method as claimed in claim 14, further comprising:

before transmitting said message, indicating an available message length to a user.

16. A method as claimed in claim 14, further comprising:

if each of said input identifiers is a stored identifier relating to a recipient which supports message compression, allowing input of a message of a length which can be transmitted only with compression 17. A communications device, comprising:

an identifier detector, for detecting an identifier relating to a sender of an incoming message; a compression detector, for determining whether the incoming message is compressed; and a memory, for storing the identifier relating to the sender of an incoming message if it is determined to be compressed, together with an indication that said sender supports message compression.

18. A communications device, comprising:

an identifier detector, for detecting an input identifier relating to an intended recipient of an outgoing message; a comparis= device, for comparing said input identifier with stored identifiers relating to rec-oients which support message compression; and -13 a processor, for transmitting said outgoing message in compressed form if said input identifier is a stored identifier relating to a recipient which supports 19. method comprising:

message compression.

A method of handling a short message, the receiving a message in compressed form; determining whether an intended recipient supports compression; and if the intended recipient supports compression, sending the message to the intended recipient in compressed form, and if the intended recipient does not support compression, sending the message to the intended recipient in 20. A means means recipient means concatenated form if necessary. communications network, comprising: for receiving a message in compressed form; for determining whether an intended supports compression; and for sending the message to the intended recipient in compressed form, if the intended recipien compression, or in concatenated form if if the intended recipient does not support supports necessary. compression