GB2405768A

GB2405768A - Image transmission via a mobile telecommunications network

Info

Publication number: GB2405768A
Application number: GB0320635A
Authority: GB
Inventors: Peter Richard Thompson
Original assignee: Vodafone Group PLC
Current assignee: Vodafone Group PLC
Priority date: 2003-09-03
Filing date: 2003-09-03
Publication date: 2005-03-09
Anticipated expiration: 2023-09-03
Also published as: GB2405768B; GB0320635D0

Abstract

The invention relates to a 3G mobile telecommunications network having an IP based multimedia subsystem (IMS). The IMS architecture may support at least the following communication types: voice, video, instant messaging, "presence" (a user's availability for contact), location-based services, email and web. A SIP Protocol is a session based protocol designed to establish IP based communication sessions between a first device and a second device. A SIP session is established, and a communication session between first and second devices can be carried out using a variety of different protocols. At the beginning of a communication session, communication between the devices may be by transmission of voice data (speech). During the session, and without terminating voice call, an image captured by the first device may be transmitted to the second device. Prior to transmission of the image from the first device to the second device, the first device obtains from the second device image quality criteria indicative of the ability of the second device to display received images. The first device modifies (if required) the image data in accordance with the image quality criteria prior to sending the image data to the second device. In this manner, the image data sent to the second device is adjusted and optimised for the display capabilities of the second device. This will allow for the best quality image to be displayed on the second device and/or will prevent waste of network resources (for example, by not transmitting image data which cannot be displayed by the second device).

Description

lllAGE TRANSMISSION VLA A MOBILE TECOMMUNICATIONS

NETWORK

The present invention relates to a method of transferring an image from a first device to a second device via a mobile telecommunications network, a mobile telecommunication system which implements this method and a device suitable for use in the system or method.

When mobile or cellular telecommunication systems were initially launched communication between mobile devices was limited solely to voice communication. This was later supplemented by the Short Message Service (SMS) and more recently Multimedia Messaging Service (MMS) technology, allowing users to send text and pictures to other devices.

With MMS, users can take a picture with a built-in camera on their mobile device and send it to another user with a compatible device, which provides users with a convenient way to share visual information.

The AIMS service however has a number of disadvantages.

Firstly, MMS operation is separate to a standard voice call - MMS messages are sent by connecting a mobile terminal to an MMS server over a General Packet Radio Service (GPRS) data connection. Voice calls are transmitted conventionally by circuit switched connections, and GPRS data, of course, is transmitted by packet switched connections. Current devices do not support simultaneous circuit switched and packet switched connections. Therefore, an MMS message can only be sent when a voice call is not underway. A user cannot send a MMS during a voice call - the call would need to be terminated before the MMS message can be sent, detracting from the spontaneity of MMS.

Secondly there are a variety of different mobile devices that support MMS, each with different screen capabilities. Both the colour depth (the number of colours supported) and resolution of the screen can differ between devices.

This can be a potential problem when a user with a particular device attempts to send an image to a user with a different device having different screen capabilities. The image may not be correctly displayed on the receiving user's device.

Thirdly, the MMS system can be potentially wasteful of network resources because images may be sent to users that cannot be successfully displayed - because of an incompatibility between screen capabilities or a complete lack of MMS facilities on the receiving device, for example. Efficient use of GPRS resources is important because GPRS operates with a comparatively low bandwidth to other bearers. Presently the MMS system limits the image size that can be sent to mitigate this problem. However, this sets an image size threshold that may be too low for mobile devices with comparatively high- resolution capabilities, so that the best quality image is not displayed. This will be an increasing problem as device technology improves and display capabilities increase.

The third generation partnership project (3GPP) has recently defined a new concept known as IMS (IP - based Multimedia Subsystem). The aim of IMS is to allow users such as mobile telephone network operators to provide services to their subscribers as efficiently and effectively as possible. For example, the IMS architecture is likely to support the following communication types: voice, video, instant messaging, 'presence" (a user's availability for contact), location-based services, email and web. Further communication types are likely to be added in the future.

This diverse collection of communication devices requires efficient session management due to the number of different applications and services that will be developed to support these communication types. The 3GPP have chosen Session Initiation Protocol (SIP) for managing these sessions.

The SIP protocol is a session-based protocol designed to establish IP based communication sessions between two or more end points or users. Once a SIP session has been established, communication between these end points or users can be carried out using a variety of different protocols (for example those designed for streaming audio and video). These protocols are defined in the SIP session initiation messages.

With IMS, users are no longer restricted to a separate voice call or data session.

Sessions can be established between mobile devices that allow a variety of communication types to be used and media to be exchanged. The sessions are dynamic in nature in that they can be adapted to meet the needs of the end users. For example, two users might start a session with an exchange of instant messages and then decide that they wish to change to a voice call, possibly with video. This is all possible within the IMS framework. If a user wishes to send a file to another user and the users already have a session established between each other (for example, a voice session) the session can be redefined to allow a data file exchange to take place. This session redefinition is transparent to the end user.

According to a first aspect of the present invention, there is provided a method of transferring an image from a first device to a second device via a mobile telecommunications network, the method including establishing in the first device data representing an image for transmission to the second device; receiving in the first device from the network image quality criteria; modifying the image data in the first device in accordance with the image quality criteria if required by the criteria; and transmitting the image data from the first device i to the second device..

Such a method may allow near real-time image exchange within the IMS framework. The receipt of the image quality criteria may allow the first device to tailor the image data that it sends to the second device, so that it is optimised.

For example, this could mean that, the image when displayed on the second device has the best quality (for example, optimised colour depth and resolution) but is not an unnecessary large file that includes image data that would be redundant to the second device. This may optimise the quality of the received image, make efficient use of the mobile telecommunication network resources and prevent unnecessary delays in transmission of the image (because no unnecessary data is sent).

According to a second aspect of the present invention, there is provided a mobile telecommunications device including means for establishing data I representing an image for transmission to another device; means for receiving image quality criteria; means for modifying the image data in accordance with the image quality criteria if required by the criteria; and means for transmitting the image data from the first device to the other device. i According to a third aspect of the present invention, there is provided a mobile telecommunications system including a first device and a second device and a Session Initiation Protocol (SIP) server for allowing the establishment of a communication session between the first device and the second device, wherein said first device includes means for establishing data representing an image for transmission to the second device, means for transmitting to the second device a request for image quality criteria therefrom representative of the ability of the second device to display image data, means for receiving from the second device the image quality criteria, means of modifying the image data in the first device in accordance with the image quality criteria if required by the criteria, i means for transmitting the image data from the first device to the second device; and the second device including means for transmitting the said image quality criteria to the first device..

A method and system for transferring an image from the first device to a second device via a mobile telecommunications network and a device for use in that system or for implementing that method, embodying the invention, will now be described by way of example, with reference to the accompanying drawings in which: Figure 1 shows schematically the elements of a communication system which allows communications between terminals managed by SIP; Figure 2 shows the data communication between a terminal, a SIP network server and a further terminal for initiating a communication session; and I Figure 3 shows in more detail the data communicated between respective terminals to allow an image to be transferred in accordance with the embodiment of the present invention. i The communication system of Figure 1 allows communication between a; mobile telephony enabled PDA (Personal Digital Assistant) 1, a mobile telephone 3 and a PC (Personal Computer) 5. Ihe PDA 1 and mobile 3 subscribe to and communicate via 3G mobile telephone network 7. The PDA 1 and the mobile 3 are capable of IP based communications using SIP.

A SIP server 9 allows SIP based communication between the PDA 1 and mobile 3 via the 3G network 7.

In a known manner, PDA 1 begins a communication session by the PDA 1 issuing an SIP INVITE REQUEST message addressed to the user name of the mobile 3. The user name is transmitted wirelessly by 3G network 7 to the SIP server 9. The SIP server 9 determines the current location of the user name associated with mobile 3 and provides the current network address for the user name associated with mobile 3. A communication session may then commence between the PDA I of the mobile terminal 3 via 3G network 7.

In this example, the PDA I and the mobile terminal 3 are in the same; "domain". In the event that PDA I wished to communicate with the user of PC 5, which is in a different domain, the user name is provided via the 3G network 7 to SIP server 9 as before. The server 9 determines that the user name associated with the PC 5 is not one within the domain of the server 9. The message from the PDA 1 is then passed to a second server 11 which is associated with a second domain (the domain of the PC 5). The second SIP server 11 provides the current address within the second domain of the PC 5, which allows the transmission of messages from the PDA 1 to the PC 5 via internet connection 13. Communications between the PC 5 and the PDA 1 will pass successfully through the internet 3, the second SIP server 11, the first SIP server 9 and 3G network 7. To initiate a communication session between the PDA 1 and the PC 5, a SIP INVITE REQUEST message will be sent, as before. I The setting up of a communication session between PDA 1 and mobile 3 will now be described in more detail with reference to Figure 2.

The PDA 1 sends an INVITE REQUEST message 15 addressed to the URL known to it for the mobile 3. The INVITE REQUEST message 15 is passed to the SIP Server 9. The SIP server 9 determines the address of the mobile 3 corresponding to the URT provided by the PDA 1 and sends an INVITE REQUEST message 17 to the mobile 3. In response the mobile 3 sends an INVITE RESPONSE message 19 to the SIP server 9. This INVITE RESPONSE message, 21, is forwarded by the SIP server 9 to the PDA1. After receiving the INVITE RESPONSE message 21 from the SIP server 9, a call session 23 may be established between the PDA I and the mobile 3.

Thus, far what has been described is how a SIP communications network operates conventionally. In addition to the messages sent between the PDAl, I SIP server 9 and mobile 3, other messages will be sent in order to establish a i session. However, this is not discussed here for sake of brevity, as these arrangements will be known to those skilled in the art.

In the embodiment of the presentation now to be described, the communication session 23 is initiated with a voice call 25. The initial communication used in the session may be set as a default by the SIP server 9, or may be selected during the INVITE REQUEST/RESPONSE phase of the session initiation.

In accordance with a primary aspect of the present embodiment, the user of PDA 1 is able to transmit an image 27 during the session 23 without terminating the voice call 25.

Figure 3 shows schematically the modifications made to a conventional PDA 1 l and mobile terminal 3 and the data exchanges occurring between those devices in the embodiment of the invention.

The PDA 1 includes software application PTSSender 29. This application is activated while the PDA 1 is operational. PTSSender application 29 causes the PDA1 to display the text "Press to See" (or other suitable text) 31 above "soft key" 33 of the PDA 1 (Figure 1) during communication session 23. A soft key is a key whose function may be changed by re-programming the key.

The PDA 1 includes a camera 35. The user may capture an image taken bycamera 35 in a conventional manner, and the captured image will be stored in memory location 37 on the PDA 1. The mechanism by which the image is captured and stored may be one of the known mechanisms implemented or currently available mobile telephones which include camera/picture functionality. The PTS Sender 29 interfaces with the application providing the cameralpicture functionality and, on activation of the "soft key" 33 during the I session 23 (which up to now has been a voice call 25) sends a screen capability; profile request 39 to mobile 3. This is a request in a pre-determined format for information about the display capabilities of the mobile terminal 3. For example, the SCP request 39 may ask for details of the colour depth (number of colours supported) and resolution of the display of mobile telephone 3, and any other information which might be useful.

Mobile terminal 3 runs an application PTS Listener 41 while the mobile 3 is operational. When the SCP request 39 is received by mobile 3, the control software on the mobile 3 recognises that We SCP should be directed to the PTS Listener 41, and transmits the SCP request 39 to the PTS Listener 41. The PTS Listener 41 then obtains screen capability data from storage location 43, including the capabilities of the display as requested by the SCP request 39 and passes this to PTS Sender application 29A present on mobile terminal 3. The I PTS Sender application 29A generates an SCP profile message 45 in a pre determined format and sends this to PTS Listener application 41A present on PDA 1. The SCP profile message 45 includes the information requested by the SCP request 39.

The PTS Sender application 29 running on PDA1 and PTS Sender application 29A running on mobile 3 have the same functionality as do the PTS Listener application 41 running on mobile 3 and the PTS Listerner application 41A running on the PDA I. Implementations of the applications on those respective devices may differ so that the applications can interface with other applications running on the devices, but the functionality will remain essentially the same.

The PTS Listener application 41A of the PDA 1 transmits the SCP profile I message 45 to the PTS sender application 29. The PTS Sender application 29 then retrieves the stored image to be sent from storage location 37. The PTS Sender application 29 then adjusts or manipulates the image so that it has a format which renders the image optimised according to the data contained in the SCP profile message 45 received from the mobile terminal 3. In this way, before the image to be sent is transmitted from the PDA 1, the image is manipulated, adjusted and optimised in accordance with the characteristics of the display of the receiving mobile 3. The adjusted image 47 is sent then by PTS Sender 29 of the PDA 1 to PTS Listener of mobile 3. The image is then displayed on the screen 49 of the mobile 3.

When the image has been displayed on screen 49, the PTS Listener 41 sends a request to the PTS Sender 29A to generate an image receipt message 51 which is transmitted to PTS Listener 41A of PDA 1, which confirms that the image has been successfully received and displayed by mobile 3. When received, the I PTS Listener application 41A of PDA 1 forwards the image receipt message 51 to the PTS Sender 29. The PTS Sender 29 maintains a list of images sent. The image receipt message 51 includes data identifying the image received by the mobile 3. This is extracted by the PTS Sender application 29 and a successful transmission of the image to the mobile 3 is noted. An acknowledgement message 53 is then sent from the PTS Sender 29 of PDA I to the mobile 3, where it is noted and received by the by the PTS Listener application 41.

Advantageously, PTS Sender 29 is programmed so that, if an image receipt message 51 is not received in respect of an image transmitted by PTS Sender 1.0 29 after a pre-determined time period, the image is re-sent, as a non- receipt of the message 51 indicates some problem with the image transmission.

When the image 47 is received by the mobile 3, the PTS Listener application 41 may either display the image immediately on the screen 49, or may prompt I the user, conveniently by display of a message 55 above soft key 57, that an image has arrived and will be displayed on activation of the soft key 57. The particular mode of operation may be selected by the user of mobile 3 in accordance with the circumstances.

The PTS Sender applications 29 and 29A, and the PTS Listener applications 41 and 41A may be implemented by any suitable means. For example, they could be implemented using Mobile Java (J2ME). The latest edition of this platform supports the MIDP 2.0 standard and allows "listeners" to be set up on a mobile terminal so that an application can be triggered on receipt of a particular network message. This will allow the PTS Listener application 41, 41A to receive and respond to messages from the PTS Sender application 29, 29A. i This J2ME system can be integrated into the IMS system.

As indicated above, it is necessary for the PTS Sender applications, 29 and 29A I and PTS Listener applications 41, 41A to interface with the camera 35 and screen 49 of the mobile devices. This may be achieved by using an application programming interface (API) provided by the handset manufacturer for the camera and screen, so that the PTS sender and PTS Listener applications may control these devices. It is possible that in the future, the camera and screen

APIs will become part of the J2ME specification.

As indicated above, the PTS Sender and PTS Listener applications on each of the PDA 1 mobile and mobile 3 have the same functionality. It is therefore 1.1 also possible for the user of mobile 3 to send an image to PDA 1 during the communication session 23 in the manner described above.

The SCP profile message 45 may be transmitted between the PDA 1 and the mobile 3 in a number of different ways. One suitable method of transmission is I to send the SCP profile as part of an SDP (Session Description Protocol) message. (The SDP is used within an IMS network to transfer information relating to the supported media types, it can however be used to transfer arbitrary information between devices.) For efficiency, the SCP message 45 is only requested once per communication session 23. However, the SCP profile message 45 can be sent more frequently, if necessary.

Although the embodiment described relates to the exchange of image data between a PDA 1 and a mobile 3, it should of course be appreciated that the invention is applicable to other devices. For example, an image could be i transmitted between the PDA 1 or mobile 3 and the PC 5.

Prior to initiation of the communication session 23, the communication types I supported by the devices to take part in the communication session 23 may be determined in accordance with the procedure described in our co-pending United Kingdom patent application No. GB0302568.1 ("Softkey SIP"), which is hereby incorporated by reference.

It should be appreciated that, although in the embodiment soft keys are used to control the sending and, possibly, receipt of image data, these activities may be controlled by other means - for example, by means of a menu or other suitable user interface.

In the embodiment the image is adjusted by the PTS Sender so that it is optimised for the screen capability of the receiving device. However, the PTS Sender may adjust the image in dependence upon other criteria instead. For example, the image quality may be varied in dependence upon the bandwidth of the network 7 and/or in dependence upon the level of congestion in the network 7 in which the receiving/or sending device is operating. This information may be provided to the PTS Sender by a special message from the network 7. The PTS Sender will then adjust the image to take into account the available network capacity. For example, if the network is heavily congested, the PTS Sender will reduce the resolution and/or the colour depth (the number of colours supported) so that the transmission of the image consumes less network resources.

The quality of service (QoS) of the communication session 23 may be set during the initiation of the communication session 23 using standard SIP techniques. This QoS information may be taken into account by the PTS Sender and may be used to adjust the image quality so that it is in accordance with the QoS information.

Claims

1. A method of transferring an image from a first device to a second device via a mobile telecommunications network, the method including establishing in the first device data representing an image for transmission to the second device; receiving in the first device from the network image quality criteria; modifying the image data in the first device in accordance with the image quality criteria if required by the criteria; and transmitting the image data from the first device to the second device.

2. The method of claim 1, wherein the image quality criteria is received from the second device and is indicative of the image display facilities provided by the second device.

3. The method of claim 1 or 2, wherein the image quality criteria are indicative of the data transfer capabilities of the mobile telecommunications network.

4. The method of claim 1, 2 or 3, wherein a communication session is established between the first device and the second device, and the image is transmitted during that session.

5. The method of claim 4, wherein, during the session, data in formats other than image data is transmitted between the first device and the second device.

6. The method of claim 5, wherein said other formats include one or more of voice data, instant messaging data, presence data (a user's availability to contact), location dependent data, email data and web data. 1.4

7. The method of claim 4, 5 or 6, wherein the session comprises a Session Initiation Protocol (SIP) session.

8. The method of any one of the preceding claims, wherein the image is transferred from said first device in response to a command from the user of that device.

9. The method of claim 8, wherein said user command is provided by activation of a soft key provided by said first device.

10. The method of any one of the preceding claims, wherein the said image data comprises audio and video data.

11. The method of any one of the preceding claims, wherein the image data allows reproduction of moving images.

12. The method of any one of the preceding claims, including establishing in the second device data representing an image for transmission to the first device; providing to the second device image quality criteria indicative of the i ability of the first device to display image data, for allowing the second device to modify the image data if required before transmission to the first device; and receiving image data from the second device for display on the first device.

13. The method of any one of the preceding claims, wherein the mobile telecommunications network comprises a 3G (UMTS) network.

14. A mobile telecommunications device including means for establishing data representing an image for transmission to another device; means for receiving image quality criteria; means for modifying the image data in accordance with the image quality criteria if required by the criteria; and means for transmitting the image data from the first device to the other device.

15. The device of claim 14, wherein the image quality criteria is received from the other device and is indicative of the image display facilities provided by the other device.

16. The device of claim 14 or 15, wherein the image quality criteria are i indicative of the data transfer capabilities of the mobile telecommunications network.

17. The device of claim 14, 15 or 16, wherein the image data is transmitted during a communication session established between the said device and the other device.

18. The device of claim 17, including means for transmitting, during the session, data in formats other than image data between the said device and the other device.

19. The device of claim 18, wherein said other formats include one or more of voice data, instant messaging data, presence data (a user's availability to contact), location dependent data, email data and web data.

20. The device of claim 17, 18 or 19, wherein the session comprises a Session Initiation Protocol (SIP) session.

21. The device of any one of claims 14 to 20, including means for transferring the image from the said device in response to a command from the user of that device. 1.6

22. The device of claim 21, wherein said user command is provided by activation of a soft key provided by said device.

23. The device of any one of claims 14 to 22, wherein the said image data comprises audio and video data.

24. The device of any one of claims 14 to 23, wherein the image data allows reproduction of moving images. t

25. The device of any one of claims 14 to 24, wherein the mobile telecommunications network comprises a 3G (UMTS) network.

26. A mobile telecommunications system including a first device and a second device and a Session Initiation Protocol (SIP) server for allowing the establishment of a communication session between the first device and the second device, wherein said first device includes: means for establishing data representing an image for transmission to the second device, means for transmitting to the second device a request for image quality criteria therefrom representative of the ability of the second device to display image data, means for receiving from the second device the image quality criteria, means for modifying the image data in the first device in accordance with the image quality criteria if required by the criteria, and means for transmitting the image data from the first device to the second device; and wherein the second device includes means for transmitting the said image; quality criteria to the first device.

27. The system of claim 26, wherein the image quality criteria are indicative of the image display facilities provided by the second device.

28. The system of claim 26 or 27, wherein the image quality criteria are indicative of the data transfer capabilities of the mobile telecommunications network.

29. The system of claim 26, 27 or 28, wherein the image data is transmitted t during a communication session established between the first device and the second device.

30. The system of claim 29, including means for transmitting, during the session, data in formats other than image data between the first device and the second device.

31. The system of claim 30, wherein said other formats include one or more of voice data, instant messaging data, presence data (a user's availability to contact), location dependent data, email data and web data.

32. The system of claim 29, 30 or 31, wherein the session comprises a Session Initiation Protocol (SIP) session.

33. The system of any one of claims 26 to 32, including means for transferring the image from the first device in response to a command from the user of that device.

34. The system of claim 33, wherein said user command is provided by activation of a soft key provided by said first device.

35. The system of any one of claims 26 to 34, wherein the said image data comprises audio and video data. I

36. The system of any one of claims 26 to 35, wherein the image data allows reproduction of moving images. i

37. The system of any one of claims 26 to 36, wherein the mobile telecommunications network comprises a 3G (UMTS) network.

38. The system of any one of the preceding claims, including means for establishing in the second device data representing an image for transmission to the first device; means for providing to the second device image quality criteria indicative of the ability of the first device to display image data, for allowing the second device to modify the image data if required before transmission to the first device; and wherein the first device includes means for receiving image data from the second device for display on the first device.

39. A method, device or system substantially hereinbefore described with reference to and/or substantially as illustrated in any one or any combination of the drawings.