Title of Invention	A COMMUNICATION TERMINAL AND A METHOD FOR RECEIVING AND FOR TRANSMITTING MESSAGES
Abstract	A communication terminal (KE) comprising means for receiving (RM) and for transmitting (SM) messages; and a subscriber identity module (SIM) which can be exchanged by a user, the communication terminal being operable to interact with the subscriber identify module (SIM), the subscriber identity module comprising functions (DKF) for one of compressing and decompressing atleast one received message which is to be transmitted.

Title of Invention

A COMMUNICATION TERMINAL AND A METHOD FOR RECEIVING AND FOR TRANSMITTING MESSAGES

Abstract

A communication terminal (KE) comprising means for receiving (RM) and for transmitting (SM) messages; and a subscriber identity module (SIM) which can be exchanged by a user, the communication terminal being operable to interact with the subscriber identify module (SIM), the subscriber identity module comprising functions (DKF) for one of compressing and decompressing atleast one received message which is to be transmitted.

Full Text	2 FIELD OF INVENTION The present invention relates to communications terminal and methods for compressing and / or decompressing received messages or messages to be transmitted. BACKGROUND OF THE INVENTION The GSM standard (Global System for Mobile Communication) mobile radio system which has been adopted throughout the world provides the possibility of transmitting text messages. This can be carried out both between two subsaiber terminals (point to point) or also to a multiplicity of subscriber terminals (broadcast mode). Because the transmission rate or the number of characters to be transmitted per message is limited, there is a need for compression of the text messages to be transmitted. The present invention is based on the object of specifying a technical teaching with which the compression and decompression of text messages is possible in a way which is appropriate for the particular requirements of the transmission of text messages by means of mobile radio systems. This object is achieved by means of a communications terminal and by means of a method for decompressing a received message in a communication terminal, and by means of a method for compressing a message to be transmitted in a communications terminal according to the features of the invention. 3 SUMMARY OF THE INVENTION The invention is based here on the concept of equipping subscriber identity modutes (SIM) which are usually present in mobile phones with functions for compressing and / or decompressing received messages or messages to be transmitted. This solution has various advantages. On the one hand, a network operator can use its own compression and decompression algorithm. On the other hand, mobile phones which are already available on the market and which support corresponding subscriber identity modules can be expanded by using a new subscriber identity module or else by reconfiguring an existing subscriber identity module with the described functional feature. Advantageous developments of the invention are the subject matter of the subordinate patent claims. The invention will be explained in more detail below with reference to preferred exemplary embodiments and a figure. BRIEF DESCRIPTION OF THE ACCOMPANYING FIGURES Figure 1 shows a schematic view of a communications terminal (KE) according to the present invention. This communication terminal comprises means for receiving (RM) and for transmitting (SM) messages and means (IM) for interacting with a subscriber Identity module (SIM) which can be exchanged by a 4 user. The subscriber identity module comiprises functions (DKF) for compressing and decompressing received messages or messages to be transmitted. The messages are received or transmitted via what is referred to as an air interface (AI). Figure 2 shows a schematic view of how the decompression sequence conventionally proceeds (prior art). Figure 3 shows a schematic view of how the decompression sequence according of the present invention proceeds. Figure 4 shows a schematic view of how the compression sequence conventionally proceeds (prior art). Figure 5 shows a schematic view of how the compression sequence according to the present invention proceeds. DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT OF THE INVENTION The invention will be described in more detail below using preferred exemplary embodiments and with reference to the figures. ¦T According to one preferred exemplary embodiment of the present invention, the functions for compressing and decompressing received messages or messages to be transmitted are divided between the terminal and the subscriber identity 5 module in such a way that two different subscriber identity modules (SIM) can permit two different methods for compressing and decompressing messages to be carried out in conjunction with the same terminal. According to another preferred embodiment of the invention, all the functions for compressing and decompressing received messages or messages to be transmitted are carried out by device or software objects which are assigned to the subscriber identity module (SIM) and not to the terminal. In a method for decompressing a received message in a communication terminal according to the present invention, a device of the terminal detects, by means of a feature of this message (for example what is referred to as the message header), that the message is a compressed message. This device or a further device of the terminal subsequently passes on this message to the subscriber identity module for decompression. During the compression of a message to be transmitted in a communications terminal according to the present inventbn, a message to be transmitted is passed on to the subscriber identity module for compression and is compressed there using functions which are assigned to the subscriber identity module, and after compression is sent back to the terminal for transmission. As result of the present invention, the algorithm for compressing or decompressing is carried out on the subscriber identity module (SIM) and Is usually implemented as a chip card. The received text messages are conveyed to the SIM, which automatically detects whether the message is compressed, and if 6 it is decompresses it is accordance with the algorithm to be applied. The decompressed message can then be displayed. If text messages are to be transmitted, they are conveyed, before the actual transmission, to the SIM where they are compressed if necessary. This can be carried out, as a function of the number of characters; for smaller quantities of data the compression could also be dispensed with. The solution according to the invention differs from known approaches for data compression especially in that the compression or decompression is not carried out by the terminal but rather by the exchangeable subscriber identity module. This provides maximum flexibility. This does not necessarily mean that all the functions or functional units which are required or involved in the compression or decompression have to be carried out or implemented on the subscriber identity module. The advantages of the invention are always obtained if the functions or functional units which are characteristic of a compression or decompression method which is used or is to be used or are characteristic of a plurality of such methods are carried out or implemented on the subscriber identity module. Such function or functional units which are a characteristic of a method can be algorithms or software modules which implement them. In addition, they can be sets of parameters, for example language - dependent or country - dependent tables. On the other hand, general functions or functional units which are present In the communications terminal in any case and are not specific to a compression 7 method or decompression method, for example processors, memory unite etc., do not generally need to be a component of the subscriber identity module. The entirety of all the functions required for the method sequence can nevertheless interact beyond the limits of the subscriber identity module. If the subscriber identity module Is exchanged, the functions, parameters, or the like which are characteristic of a specific data compression method or decompression method are exchanged with It. As a result, it becomes possible, depending on the type of subscriber identity module installed, to use different data compression methods or decompression methods in conjunction with this terminal. 8 We Claim . A communication terminal (KE) comprising means for receiving (RM) and for transmitting (SM) messages; and a subscriber identity module (SIM) which can be exchanged by a user, the communication terminal being operable to interact with the subscriber identify module (SIM), the subscriber identity module comprising functions (DKF) for one of compressing and decompressing atteast one received message which is to be transmitted. , The communications terminal as claimed in claim 1, wherein the functions for one of compressing and decompressing atleast one received message which is to be transmitted being divided between the terminal and the subscriber identity module in such a way that two different subscriber identity modules can permit two different methods for one of compressing and decompressing the atleast one message to be carried out in association with the same terminal. The communication terminal as claimed in claim 2, wherein all the functions for one of compressing and decompressing the atleast one received message to be transmitted is carried out by atleast one device assigned to the subscriber identity module, and wherein said functions not being assigned to the terminal. A method for decompressing a received message in a communication terminal, the communication terminal comprising the steps of detecting by a device of the terminal the compressed state of a message by means of a feature of the message; and passing on the message by a device (IM) of the terminal to the subscriber identity module (SIM) for decompression. 9 5. A method for compressing a message to be transmitted in a communication terminal comprising the steps of: passing a transmlttable message to the subscriber identity module for compression; compressing the message in the subscriber identity module using functions (DKF) which are assigned to the subscriber identity module; and sending back the compressed message to the terminal for transmission. A communication terminal (KE) comprising means for receiving (RM) and for transmitting (SM) messages; and a subscriber identity module (SIM) which can be exchanged by a user, the communication terminal being operable to interact with the subscriber identify module (SIM), the subscriber identity module comprising functions (DKF) for one of compressing and decompressing atleast one received message which is to be transmitted.

Full Text

2 FIELD OF INVENTION
The present invention relates to communications terminal and methods for compressing and / or decompressing received messages or messages to be transmitted.
BACKGROUND OF THE INVENTION
The GSM standard (Global System for Mobile Communication) mobile radio system which has been adopted throughout the world provides the possibility of transmitting text messages. This can be carried out both between two subsaiber terminals (point to point) or also to a multiplicity of subscriber terminals (broadcast mode). Because the transmission rate or the number of characters to be transmitted per message is limited, there is a need for compression of the text messages to be transmitted.
The present invention is based on the object of specifying a technical teaching with which the compression and decompression of text messages is possible in a way which is appropriate for the particular requirements of the transmission of text messages by means of mobile radio systems. This object is achieved by means of a communications terminal and by means of a method for decompressing a received message in a communication terminal, and by means of a method for compressing a message to be transmitted in a communications terminal according to the features of the invention.

3
SUMMARY OF THE INVENTION
The invention is based here on the concept of equipping subscriber identity modutes (SIM) which are usually present in mobile phones with functions for compressing and / or decompressing received messages or messages to be transmitted. This solution has various advantages. On the one hand, a network operator can use its own compression and decompression algorithm. On the other hand, mobile phones which are already available on the market and which support corresponding subscriber identity modules can be expanded by using a new subscriber identity module or else by reconfiguring an existing subscriber identity module with the described functional feature.
Advantageous developments of the invention are the subject matter of the subordinate patent claims.
The invention will be explained in more detail below with reference to preferred exemplary embodiments and a figure.
BRIEF DESCRIPTION OF THE ACCOMPANYING FIGURES
Figure 1 shows a schematic view of a communications terminal (KE) according to the present invention. This communication terminal comprises means for receiving (RM) and for transmitting (SM) messages and means (IM) for interacting with a subscriber Identity module (SIM) which can be exchanged by a

4
user. The subscriber identity module comiprises functions (DKF) for compressing and decompressing received messages or messages to be transmitted. The messages are received or transmitted via what is referred to as an air interface (AI).
Figure 2 shows a schematic view of how the decompression sequence conventionally proceeds (prior art).
Figure 3 shows a schematic view of how the decompression sequence according of the present invention proceeds.
Figure 4 shows a schematic view of how the compression sequence conventionally proceeds (prior art).
Figure 5 shows a schematic view of how the compression sequence according to the present invention proceeds.
DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT OF THE INVENTION
The invention will be described in more detail below using preferred exemplary embodiments and with reference to the figures.
¦T
According to one preferred exemplary embodiment of the present invention, the functions for compressing and decompressing received messages or messages to be transmitted are divided between the terminal and the subscriber identity

5
module in such a way that two different subscriber identity modules (SIM) can permit two different methods for compressing and decompressing messages to be carried out in conjunction with the same terminal.
According to another preferred embodiment of the invention, all the functions for compressing and decompressing received messages or messages to be transmitted are carried out by device or software objects which are assigned to the subscriber identity module (SIM) and not to the terminal.
In a method for decompressing a received message in a communication terminal according to the present invention, a device of the terminal detects, by means of a feature of this message (for example what is referred to as the message header), that the message is a compressed message. This device or a further device of the terminal subsequently passes on this message to the subscriber identity module for decompression.
During the compression of a message to be transmitted in a communications terminal according to the present inventbn, a message to be transmitted is passed on to the subscriber identity module for compression and is compressed there using functions which are assigned to the subscriber identity module, and after compression is sent back to the terminal for transmission.
As result of the present invention, the algorithm for compressing or decompressing is carried out on the subscriber identity module (SIM) and Is usually implemented as a chip card. The received text messages are conveyed to the SIM, which automatically detects whether the message is compressed, and if

6
it is decompresses it is accordance with the algorithm to be applied. The decompressed message can then be displayed. If text messages are to be transmitted, they are conveyed, before the actual transmission, to the SIM where they are compressed if necessary.
This can be carried out, as a function of the number of characters; for smaller quantities of data the compression could also be dispensed with.
The solution according to the invention differs from known approaches for data compression especially in that the compression or decompression is not carried out by the terminal but rather by the exchangeable subscriber identity module. This provides maximum flexibility.
This does not necessarily mean that all the functions or functional units which are required or involved in the compression or decompression have to be carried out or implemented on the subscriber identity module. The advantages of the invention are always obtained if the functions or functional units which are characteristic of a compression or decompression method which is used or is to be used or are characteristic of a plurality of such methods are carried out or implemented on the subscriber identity module. Such function or functional units which are a characteristic of a method can be algorithms or software modules which implement them. In addition, they can be sets of parameters, for example language - dependent or country - dependent tables.
On the other hand, general functions or functional units which are present In the communications terminal in any case and are not specific to a compression

7
method or decompression method, for example processors, memory unite etc., do not generally need to be a component of the subscriber identity module. The entirety of all the functions required for the method sequence can nevertheless interact beyond the limits of the subscriber identity module.
If the subscriber identity module Is exchanged, the functions, parameters, or the like which are characteristic of a specific data compression method or decompression method are exchanged with It. As a result, it becomes possible, depending on the type of subscriber identity module installed, to use different data compression methods or decompression methods in conjunction with this terminal.

8
We Claim
. A communication terminal (KE) comprising means for receiving (RM) and for transmitting (SM) messages; and a subscriber identity module (SIM) which can be exchanged by a user, the communication terminal being operable to interact with the subscriber identify module (SIM), the subscriber identity module comprising functions (DKF) for one of compressing and decompressing atteast one received message which is to be transmitted.
, The communications terminal as claimed in claim 1, wherein the functions for one of compressing and decompressing atleast one received message which is to be transmitted being divided between the terminal and the subscriber identity module in such a way that two different subscriber identity modules can permit two different methods for one of compressing and decompressing the atleast one message to be carried out in association with the same terminal.
The communication terminal as claimed in claim 2, wherein all the functions for one of compressing and decompressing the atleast one received message to be transmitted is carried out by atleast one device assigned to the subscriber identity module, and wherein said functions not being assigned to the terminal.
A method for decompressing a received message in a communication terminal, the communication terminal comprising the steps of detecting by a device of the terminal the compressed state of a message by means of a feature of the message; and passing on the message by a device (IM) of the terminal to the subscriber identity module (SIM) for decompression.

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5. A method for compressing a message to be transmitted in a communication terminal comprising the steps of: passing a transmlttable message to the subscriber identity module for compression; compressing the message in the subscriber identity module using functions (DKF) which are assigned to the subscriber identity module; and sending back the compressed message to the terminal for transmission.
A communication terminal (KE) comprising means for receiving (RM) and for transmitting (SM) messages; and a subscriber identity module (SIM) which can be exchanged by a user, the communication terminal being operable to interact with the subscriber identify module (SIM), the subscriber identity module comprising functions (DKF) for one of compressing and decompressing atleast one received message which is to be transmitted.

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Patent Number

203601

Indian Patent Application Number

IN/PCT/2002/00042/KOL

PG Journal Number

10/2007

Publication Date

09-Mar-2007

Grant Date

09-Mar-2007

Date of Filing

09-Jan-2002

Name of Patentee

SIEMENS AKTIENGESELLSCHAFT

Applicant Address

WITTELSBACHERPLATZ 2, D-80333 MUNCHEN

Inventors:

#	Inventor's Name	Inventor's Address
1	PUSL, STEFAN	BACHSTR.11, D-85406 ZOLLING
2	SASSE ,JORG	LEBERLESTR. 16,D-80995, MUNCHEN

PCT International Classification Number

H 04 Q 71/22

PCT International Application Number

PCT/EP00/03235

PCT International Filing date

2000-04-11

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1	99114134.2	1999-07-20	EUROPEAN UNION