Login| Sign Up| Help| Contact|

Patent Searching and Data


Title:
TRANSMISSION OF DATA MESSAGES IN MOBILE COMMUNICATION NETWORKS
Document Type and Number:
WIPO Patent Application WO/2008/105729
Kind Code:
A1
Abstract:
A primary node (120) of a mobile communication network (100) receives an incoming source data message (msgs) that is originated by a source station (MSA) and directed to a terminating station (MSB). A location node (130) is associated with a database storing information, which for each subscriber (MSB) in the network (100) defines a target node (160) currently responsible delivering data messages (msgs; msgMOD) wirelessly to terminating stations (MSB) located within a defined service area. A service filtering node (140) is adapted to investigate whether or not the terminating station (MSB) subscribes to a message transformation service, and if so the source data message (msgs) is forwarded to a message modifying node (150). This node (150), in turn, is adapted to produce a modified data message (msgM0D) including the source data message (msgs) and at least one added data segment (msgADD), e.g. representing an advertisement. Thereafter, the message modifying node (150) forwards the modified data message (msgMOD) to the target node (160) which according to the location node (130) is responsible for delivering data messages to the terminating station (MSB).

Inventors:
KEMPE MATS (SE)
Application Number:
PCT/SE2008/050210
Publication Date:
September 04, 2008
Filing Date:
February 26, 2008
Export Citation:
Click for automatic bibliography generation   Help
Assignee:
GIMMIX AB (SE)
KEMPE MATS (SE)
International Classes:
H04L51/58; H04L65/00; H04W4/12
Domestic Patent References:
WO2002054803A12002-07-11
WO2000044151A22000-07-27
Foreign References:
US20060194595A12006-08-31
US20020077130A12002-06-20
Other References:
See also references of EP 2127275A4
Attorney, Agent or Firm:
BJERKÉNS PATENTBYRÅ KB (Östermalmsgatan 58, Stockholm, SE)
Download PDF:
Claims:
Claims

1. A system for transmitting data messages (msg s ; msg MOD ) wireiessly to mobile stations located within the range of a mobile communication network (100), the system comprising : at least one primary node (120) adapted to receive an incoming source data message (msg s ) originated by a source station (MSA), at least one target node (160) responsible delivering data messages (msg s ; rnsg M0D ) wireiessly to terminating stations (MSB) located within a defined service area, and a location node (130) associated with a database storing information concerning a respective target node (160) for each subscriber (MSB) in the mobile communication network (100), characterized in that the system comprises a service filtering node (140) and a message modifying node (150), the service filtering node (140) being adapted to: investigate whether or not the source data message (msg s ) is directed to a terminating station (MSB) subscribing to a message transformation service, and if so forward the source data message (msg s ) to the message modifying node (150), and the message modifying node (150) being adapted to: receive the source data message (msg s ), produce a modified data message (msg M o D ) including the source data message (msg s ) and at least one added data segment (msg A DD), and forward the modified data message (msg M o D ) to a target node (160) which according to the location node (130) is responsible for delivering data messages to the termina- ting station (MSB)

2. The system according to claim 1 , wherein the service filtering node (140) is adapted to cause transmission of a final target node identifier (ID TN-F ) to a primary node (120) having received the source data message (msg s ) if it is found that the termi- nating station (MSB) does not subscribe to the message trans-

formation service.

3. The system according to claim 2, wherein the service filtering node (140) is adapted to transmit the final target node identifier (ID TN-F ) to the location node (130) which in turn is adapted to forward the final target node identifier (ID TN . F ) to the primary node (120).

4. The system according to any one of the claims 2 or 3, wherein the primary node (120) is adapted to forward the source data message (msg s ) to the target node (160) in response to a received final target node identifier (I D TN - F )-

5. The system according to any one of the claims 2 to 4, wherein the source data message (msg s ) is associated with a recipient identifier designating the terminating station (MSB), and the primary node (120) is adapted to transmit a location re- quest message (L reqB ) to the location node (130) in response to the source data message (msg s ), the location request message (L re q B ) comprising data reflecting the recipient identifier.

6. The system according to claim 5, wherein the location node (130) is adapted to transmit a filter request message (MSB chk ) to the service filtering node (140) in response to the location request message (L reqB ), and the service filtering node (140) is adapted to execute said service subscription investigation in response to the filter request message (MSB chk ).

7. The system according to any one of the preceding claims, wherein the service filtering node (140) is adapted to cause transmission of a preliminary target node identifier (ID TN- p) to the primary node (120) if the terminating station (MSB) is found to subscribe to the message transformation service, the preliminary target node identifier (ID TN . P ) specifying a network identity of a node (140; 150) to which the source data message (msg s ) is to be sent in order to constitute a basis for the modified data

message (msg M0D )-

8. The system according to claim 7, wherein the preliminary target node identifier (ID TN-P ) specifies a network identity of the message modifying node (150).

9. The system according to claim 7, wherein the preliminary target node identifier (ID TN - P ) specifies a network identity of the service filtering node (140), and the service filtering node (140) is adapted to forward any received source data message (msg s ) to the message modifying node (150).

10. The system according to any one of the claims 8 or 9, wherein, in response to a received preliminary target node identifier (ID- TM .p), the primary node (120) is adapted to send the source data message (msg s ) to a target node (140; 150) whose network identity is specified by the preliminary target node iden- tifier (ID TN -p).

11. The system according to any one of the preceding claims, wherein the modified data message (msg M o D ) is a multimedia- message.

12. The system according to any one of the preceding claims, wherein the source data message (msg s ) is a text-only message.

13. The system according to any one of the claims 1 to 11 , wherein the source data message (msg s ) is a multimedia-message.

14. The system according to any one of the preceding claims, wherein the system comprises a data supply node (170) adapted to transmit the at least one added data segment (msg ADD ) to the message modifying node (150).

15. The system according to claim 14, wherein the data supply

node (170) is associated with at least one database (175) storing information concerning individual characteristics of the subscribers to the message transformation service, and the data supply node (170) is adapted to target the at least one added data segment (msg ADD ) based on the individual characteristics of the terminating station (MSB).

16. A method of transmitting data messages (msg s ; rnsg M0D ) wirelessly to mobile stations being located within the range of a mobile communication network (100), the method comprising: receive an incoming source data message (msg s ) in a primary node (120), the source data message (msg s ) being originated by a source station (MSA), and delivering a data message (msg s ; rnsg M oD) wi re l ess 'y to a terminating station (MSB), the data message (msg s ; msg M0D ) being delivered via a target node (160) responsible delivering data messages to terminating stations (MSB) located within a defined service area, a location node (130) in the network (100) specifying information concerning a respective target node (160) for each subscriber (MSB) in the network (100), characterized by investigating in a service filtering node (140) whether or not the source data message (msg s ) is directed to a terminating station (MSB) subscribing to a message transformation service, and if so forwarding the source data message (msg s ) to a message modifying node (150) wherein a modified data message (msg M O D ) ιs produced including the source data message (msg s ) and at least one added data segment (msg ADD ), and forwarding the modified data message (msg MOD ) to a target node (160) which according to the location node (130) is responsible for delivering data messages to the terminating station (MSB).

17. The method according to claim 16, comprising transmitting a final target node identifier (ID TN-F ) to a primary node (120) ha-

ving received the source data message (msg s ) if it is found that the terminating station (MSB) does not subscribe to the message transformation service.

18. The method according to claim 17, wherein the source data message (msg s ) is associated with a recipient identifier designating the terminating station (MSB), and method comprises transmitting a location request message (L reqB ) from the primary node (120) to the location node (130) in response to the source data message (msg s ), the location request message (L req B) com- prising data reflecting the recipient identifier.

19. The method according to claim 18, comprising: transmitting a filter request message (MSB chk ) from the location node (130) to the service filtering node (140) in response to a received location request message (L reqB ), and executing said service subscription investigation in the service filtering node (140) in response to a received filter request message (MSB chk ).

20. The method according to any one of the claims 16 to 19, comprising transmitting a preliminary target node identifier (ID TN-P ) to the primary node (120) if the terminating station (MSB) is found to subscribe to the message transformation service, the preliminary target node identifier (ID TN - P ) specifying a network identity of a node (140; 150) to which the source data message (msg s ) is to be sent in order to constitute a basis for the modified data mes- sage (msg M oD)-

21 . The method according to claim 20, comprising transmitting the source data message (msg s ) from the primary node (120) to a target node (140; 150) whose network identity is specified by the preliminary target node identifier (ID TN-P ) in response to a received preliminary target node identifier (ID TN-P ).

22. The method according to any one of the claims 16 to 21 ,

comprising targeting the at least one added data segment (msg ADD ) based on individual characteristics of the terminating station (MSB) stored in at least one database (175).

23. A computer program loadable into the memory of a com- puter, comprising software for controlling the steps of any of the claims 16 to 22 when said program is run on the computer.

24. A computer readable medium, having a program recorded thereon, where the program is to make a computer control the steps of any of the claims 16 to 22 when the program is loaded into the computer.

Description:

Transmission of Data Messages in Mobile Communication

Networks

THE BACKGROUND OF THE INVENTION AND PRIOR ART

The present invention relates generally to transmission of data messages in mobile communication networks. More particularly the invention relates to a system according to the preamble of claim 1 and a method according to the preamble of claim 16. The invention also relates to a computer program according to claim 23 and a computer readable medium according to claim 24.

During the last decades the market for mobile communication and services has increased dramatically. Traditionally, traffic costs have been paid via fixed subscription fees and fees related to airtime and/or amount of data transmitted. However, in connection with intensified competition and lowered margins for the operators, alternative ways of financing the traffic and the services in the mobile networks have been developed. For example, various forms of advertisement-based subsidizing are now being used. Existing subscribers may also acquire airtime credits in relation to the number of new subscribers they trigger to sign up with their network operator.

US patent No. 6,470,181 discloses a technical solution for sponsoring airtime cost for mobile subscribers based on acceptance of commercial messages. Specifically, an advertiser is here allowed to credit a mobile subscriber after that the subscriber has listened to a recorded advertisement. A text message associa-

ted to the audio advertisement may also be sent to the subscriber, e.g . representing a transcript of the audio advertisement.

To facilitate the input of sponsoring commercial material, US patent No. 7,024,21 1 reveals a system and a method for managing text advertisements to mobile subscribers. Here, advertiser content to be included in text messages is received via an advertiser interface module. Moreover, a database may be interrogated to determine which mobile subscribers that satisfy a particular message criterion. Thus, advertisements can be targeted.

US patents No. 6,452,498 and 6,993,326 describe further examples concerning how advertisements and similar messages may be targeted to wireless terminals, e.g. based on geographic location and/or various demographic parameters.

However, the existing solutions are ail problematic for one rea- son or another. In general, subscribers tend to dislike receiving unwanted messages irrespective of the format used, be it acoustic, text or other. Therefore, instead of actually listening to the above-mentioned recorded advertisements, the subscriber might put aside the handset while the message is being played. Hen- ce, the advertisers' return becomes low. Of course, receiving commercial messages without gaining any airtime credits (or equivalent), which may be the result of some of the above solutions, will frustrate the subscribers even more.

SUMMARY OF THE I NVENTION The object of the present invention is therefore to alleviate the above problems and provide a solution which satisfies the interests of all involved parties, i.e. the advertisers, the subscribers and the network operators.

According to the invention, the object is achieved by the system as initially described, wherein the system includes a service filtering node and a message modifying node. The service filtering

node is adapted to investigate whether or not an incoming source data message is directed to a terminating station subscribing to a message transformation service. If the source data message is found to be directed to such a subscriber, the service filtering node is adapted to forward the source data message to the message modifying node. This node, in turn, is adapted to receive the source data message and produce a modified data message including the source data message and at least one added data segment. Thereafter, the modifying node forwards the modified data message to a target node which according to the location node is responsible for delivering data messages to the terminating station at its current location. Typically, this means that the modified data message passes a number of intermediary nodes between the modifying node and the target node.

The proposed system is advantageous because thereby modified messages (e.g. containing advertisements) will exclusively be sent to users who are subscribers to the message modifying service. In return, these subscribers may obtain an airtime fee reduction for services in the mobile communication system, or any other system depending on the agreement between the advertisers, the operator and the subscriber. The added data segments may be inserted into the source message in such a manner that the advertiser's message gains a satisfying exposure. Moreover, the resulting airtime credits can be expected to create a traffic increase in the network, which generates further operator incomes.

According to one preferred embodiment of the invention, the service filtering node is adapted to cause transmission of a pre- liminary target node identifier to the primary node if the terminating station is found to subscribe to the message transformation service. The preliminary target node identifier (e.g. a network address) specifies a network identity of a node to which the source data message is to be sent in order to constitute a basis for the modified data message. The preliminary target node iden-

tifier may either specify a network identity of the message modifying node, or the service filtering node, in the latter case, the service filtering node is adapted to forward any received source data message to the message modifying node.

According to another preferred embodiment of the invention, the service filtering node is adapted to cause transmission of a final target node identifier to a primary node having received the source data message, if it is found that the terminating station does not subscribe to the message transformation service. Hence, all messages which shall remain unaffected will pass smoothly through the system with minimal delay.

According to still another preferred embodiment of the invention, the service filtering node is adapted to transmit the final target node identifier to the location node, which in turn, is adapted to forward the final target node identifier to the primary node. As a result, a straightforward bidirectional interface for requesting and acquiring a relevant target node identifier is established between the primary node and the location node. Preferably, the primary node is further adapted to forward the source data mes- sage to the target node in response to a received final target node identifier.

According to yet another preferred embodiment of the invention, the source data message is associated with a recipient identifier designating the terminating station (e.g. a telephone number). Moreover, the primary node is adapted to transmit a location request message to the location node in response to the source data message, where the location request message includes data reflecting the recipient identifier. Thus, the location node may look up a relevant target node in its associated database.

According to a further preferred embodiment of the invention, the location node is adapted to transmit a filter request message to the service filtering node in response to the location request message. In response to the filter request message, the service

filtering node, in turn, is adapted to execute the service subscription investigation (i.e. check whether or not the source data massage is to be combined with any added data segments).

According to another preferred embodiment of the invention, the modified data message is a multimedia-message (e.g. represented by an MMS message in GSM (MMS = Multimedia Message Service; GSM = Global System for Mobile Communications, or Groupe Special Mobile)). The source data message, on the other hand, may be a text-only message (e.g. represented by an SMS message in GSM (SMS = Short Message Service)) as well as a multimedia-message. Hence, the modified data message may have a very rich information content. Moreover, any forwarded modified data messages will also be multimedia-messages, which is estimated to generate increased operator reve- nues in relation to transmission of text-only messages.

According to an additional preferred embodiment of the invention, the system includes a data supply node which is adapted to transmit the at least one added data segment to the message modifying node. Preferably, the data supply node is associated with at least one database storing information concerning individual characteristics of the subscribers to the message transformation service. The data supply node is further adapted to target the at least one added data segment based on the individual characteristics of the terminating station. Consequently, adverti- sements can be directed to particular types of customers depending on their demographic profile, occupation, income, current location etc. Alternatively, or as a complement to said database, the data supply node may be adapted to perform a keyword search in the source data message, match the search result against a database containing potentially addible data segments, and add data segments deemed relevant to the contents of the source data message.

According to another aspect of the invention the object is achieved by the method described initially, wherein a service filtering

node investigates whether or not the source data message is directed to a terminating station subscribing to a message transformation service. If so, the source data message is forwarded to a message modifying node, wherein a modified data message is produced including the source data message and at least one added data segment. Thereafter, the modified data message is forwarded to a target node, which according to the location node is responsible for delivering data messages to the terminating station.

The advantages of this method, as well as the preferred embodiments thereof, are apparent from the discussion above with reference to the proposed receiver.

According to a further aspect of the invention the object is achieved by a computer program, which is directly loadable into the memory of a computer, and includes software adapted to control the method proposed above when said program is run on a computer.

According to another aspect of the invention the object is achieved by a computer readable medium, having a program recorded thereon, where the program is to control a computer to perform the method proposed above when the program is loaded into the computer.

Further advantages, beneficial features and applications of the present invention will be apparent from the following description and the dependent claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention is now to be explained more closely by means of preferred embodiments, which are disclosed as examples, and with reference to the attached drawings. Figure 1 shows a block diagram of a communication system according to one embodiment of the invention; and

Figure 2 illustrates, by means of a flow diagram, a general method of transmitting data messages according to the invention.

DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION

We refer initially to Figure 1 , which shows a block diagram of a communication system according to one embodiment of the invention. The system is adapted to transmit data messages msg s and msg M o D wirelessly to mobile stations MSB being located wi- thin the range of a mobile communication network 100 included in the system.

The system includes a number of primary nodes 120 (for clarity reasons, however, Figure 1 only shows one node 120), which each is adapted to receive incoming source data messages msg s directed to terminating stations MSB. Typically, the source data message msg s is originated by a source station MSA that also is a mobile station. Nevertheless, it is technically conceivable that the source data message msg s instead is generated by a fixed terminal, such as a stationary computer or server con- nected to the Internet.

Furthermore, the network 100 includes a number of target nodes 160, which each is responsible for delivering data messages msg s and msg M o D wirelessly to terminating stations MSB located within a defined service area. Typically, the target nodes 160 have bidirectional wireless interfaces at their disposal (e.g . represented by base station radio resources) and may thus also function as primary nodes 120 for data messages originated within their respective service area. A location node 130 in the network 100 is associated with a database, which stores upda- ted information concerning a respective target node 160 for each subscriber MSB roaming in the mobile network 100 (i.e. located within the network's 100 range). Hence, whenever an incoming source data message msg s is received in the system,

the location node 130 is capable of identifying an appropriate target node 160 for delivering the message msg s to the intended terminating station MSB by consulting its database.

The system further includes a service filtering node 140 and a message modifying node 150. The service filtering node 140 is adapted to, for each source data message msg s directed to a terminating station MSB, investigate whether or not the station MSB subscribes to a message transformation service. To this aim, the node 140 is preferably associated with a database 145 over all service subscribers. If the investigation performed by the service filtering node 140 reveals that the station MSB is a subscriber to the message modifying service, the node 140 is adapted to forward the source data message msg s to the message modifying node 150. This node 150, in turn, is adapted to receive the source data message msg s , and produce a modified data message msg M oD including the source data message msg s and at least one added data segment msg A o D - For example, the source data message msg s may be a text-only message, such as a GSM SMS-message, and the modified data message msg M oD rnay be a multimedia-message wherein the added data segment msg A DD is represented by text, an audio file, an image and/or a video clip. Hence, a commercial message can be combined with the information of the source data message msg s . According to one embodiment of the invention, however, also the source data message msg s is a multimedia-message, such that the message modifying node 150 both receives and delivers multimedia-messages. In any case, after having generated the modified data message msg M0D , the node 150 is adapted to forward the message msg M o D to a relevant target node 160, i.e. the node, which according to the location node 130 is responsible for delivering data messages to the terminating station MSB.

Naturally, in order to reach the intended recipient the source data message msg s must be associated with adequate address infor- mation in the form of a telephone number or equivalent identifier

designating the terminating station MSB. According to one embodiment of the invention, the primary node 120 is adapted to transmit a location request message L reqB to the location node 130 in response to the source data message msg s . Here, the lo- cation request message L reqB includes data reflecting the recipient identifier. Thereby, based on the recipient identifier the location node 130 may execute the above-mentioned target node look-up.

Moreover, according to one embodiment of the invention, the lo- cation node 130 is adapted to transmit a filter request message MSB chk to the service filtering node 140 in response to the location request message L reqB . The node 140, in turn, is adapted to execute the above-mentioned service subscription investigation in response to the filter request message MSB chk .

According to one embodiment of the invention, the service filtering node 140 is adapted to cause transmission of a final target node identifier ID JN F to a primary node 120 having received the source data message msg s , if it is found that the terminating station MSB does not subscribe to the message transformation service. The service filtering node 140 is preferably adapted to transmit the final target node identifier ID TN-F to the location node 130 which in turn, is adapted to forward the final target node identifier ID TN-F to the primary node 120. In response to a received final target node identifier ID TN-F , the primary node 120 is preferably adapted to forward the source data message msg s to the target node 160, either directly or via one or more intermediary nodes depending on the structure and complexity of the network 100.

If, on the other hand, the service filtering node 140 finds that the terminating station MSB does subscribe to the message transformation service, the node 140 is preferably adapted to cause transmission of a preliminary target node identifier ID TN-P to the primary node 120. The preliminary target node identifier ID T N-P specifies a network identity of a node to which the source data

message msg s is to be sent in order to constitute a basis for the modified data message msg M o D - The preliminary target node identifier ID TN-P may specify either a network address to the service filtering node 140, or to the message modifying node 150. In the former case, the service filtering node 140 acts as an intermediary node, which is adapted to forward any received source data message msg s to the message modifying node 150 for further processing according to what has been described above.

Analogous to the above discussion concerning the final target node identifier I D TN-F , when the primary node 120 receives a preliminary target node identifier ID TN-P , the node 120 is adapted to send the source data message msg s to a target node whose network identity is specified by the preliminary target node iden- tifier ID TN _ P in response to the identifier ID TN-P . Hence, the source data message msg s may be sent either to the service filtering node 140 or the message modifying node 150.

As mentioned earlier, one important implementation of the proposed message modification relates to communication of adverti- sements and corresponding information, which in turn, may serve as a traffic fee reduction instrument for the subscribers being linked thereto. In short, by means of agreements between the subscriber and his/her operator, and between the operator and a number of advertisers, telecommunication traffic (e.g. in the net- work 100) can be sponsored. In order to improve the expected relevance of the advertisements, the contents of the advertisement is preferably matched against one or more parameters of a subscriber profile. For this purpose, according to one embodiment of the invention, the system includes a data supply node 170 that is adapted to transmit the at least one added data segment msg ADD to the message modifying node 150. The data supply node 170, in turn, may be associated with at least one database 175 storing information concerning individual characteristics of the subscribers to the message transformation service. When the message modifying node 150 receives a source data message msg s di-

rected to a terminating station MSB, the data supply node 170 is adapted to target the at least one added data segment msg A DD based on the individual characteristics of the terminating station MSB. Consequently, the advertisers' interests can be better sa- tisfied, and hopefully also the subscribers perceive the added data segments msg ADD as being comparatively relevant. The individual characteristics can relate to essentially constant subscriber features e.g. gender, age, income level, or occupation, as well as to variable features e.g. geographic location or veloci- ty (indicating whether the subscriber currently is stationary, walks or travels in a vehicle).

Alternatively, or as a complement to the at least one profile database 175, the data supply node 170 may be adapted to perform a keyword search in the source data message msg s - Based on the result of this search, the data supply node 170 is adapted to derive data segments (e.g. from a database), which are considered to match the search result sufficiently well, and then supply these data segments msg ADD to the message modifying node 150 for inclusion into the modified data message msg M0 D- Conse- quently, the data segments msg ADD can be fitted to harmonize the contents of the specific source data message msg s , such that for example a text message saying: "What about dinner at 5 o'clock?" can be associated with an advertisement for a restaurant. Naturally, if the profile database 175 contains information pertaining to the recipient's MSB location, the advertisement can even relate to a restaurant proximate to this location.

To sum up, we will now describe the proposed method of transmitting data messages wirelessly to mobile stations being located within the range of a mobile communication network with re- ference to the flow diagram in Figure 2.

An initial step 210 investigates whether or not an incoming source data message msg s has been received, and if not the procedure loops back and stays in step 210. Otherwise, a step 220 investigates whether or not the source data message msg s is

directed to a terminating station MSB subscribing to a message transformation service. If the investigation in step 220 reveals that terminating station MSB is not a subscriber to this service, a step 260 follows.

However, if the terminating station MSB is found to be a subscriber, the procedure continues to a step 230 wherein a modified data message msg M oD is produced. This message msg M o D includes the source data message msg s and at least one added data segment msg ADD (e.g. representing an advertisement, a traffic announcement and/or a security aiert). Then, a step 240 forwards the modified data message msg M o D to a target node, and subsequently a step 250 delivers the message msg M0D from the target node to the terminating station MSB over a wireless interface. Thereafter, the procedure loops back to step 210.

Step 260 forwards the source data message msg s (unmodified) to the target node, and then a step 270 delivers the message msg s from the target node to the terminating station MSB over a wireless interface. Finally, the procedure loops back to step 210.

It can be noted that the flow diagram in Figure 2 should be re- garded exclusively as symbolic illustration of the proposed method with respect to a given incoming data message. Namely, in an actual implementation of the method, all the steps 210 to 270 are preferably executed in parallel, such that for example when step 220 checks a first subscriber being the recipient of a first message, step 210 checks whether any second messages are received in respect of other subscribers, and so on.

AIi of the steps, as well as any sub-sequence of steps, described with reference to Figure 2, above may be controlled by means of a programmed computer apparatus. Moreover, al- though the embodiments of the invention described above with reference to the drawings comprise computer apparatus and processes performed in computer apparatus, the invention thus also extends to computer programs, particularly computer programs on or in a carrier, adapted for putting the invention into

practice. The program may be in the form of source code, object code, a code intermediate source and object code such as in partially compiled form, or in any other form suitable for use in the implementation of the procedure according to the invention. The program may either be a part of an operating system, or be a separate application. The carrier may be any entity or device capable of carrying the program. For example, the carrier may comprise a storage medium, such as a Flash memory, a ROM (Read Only Memory), for example a DVD (Digital Video/Versatile Disk), a CD (Compact Disc), an EPROM (Erasable Programmable Read-Only Memory), an EEPROM (Electrically Erasable Programmable Read-Only Memory), or a magnetic recording medium, for example a floppy disc or hard disc. Further, the carrier may be a transmissible carrier such as an electrical or opti- cal signal which may be conveyed via electrical or optical cable or by radio or by other means. When the program is embodied in a signal which may be conveyed directly by a cable or other device or means, the carrier may be constituted by such cable or device or means. Alternatively, the carrier may be an inte- grated circuit in which the program is embedded, the integrated circuit being adapted for performing, or for use in the performance of, the relevant procedures.

The term "comprises/comprising" when used in this specification is taken to specify the presence of stated features, integers, steps or components. However, the term does not preclude the presence or addition of one or more additional features, integers, steps or components or groups thereof.

The reference to any prior art in this specification is not, and should not be taken as, an acknowledgement or any suggestion that the referenced prior art forms part of the common general knowledge in Australia, or in any other country.

The invention is not restricted to the described embodiments in the figures, but may be varied freely within the scope of the claims.