The present invention is particularly, but not exclusively, suited to implementation in a video telephony system employing video user terminals such as video phones and to the display of advertisements on the video phones.

In the context of this document, video telephony is multi-way, real-time remote communication between terminals, of moving images.

Accordingly, video telephony allows a user to see the person they are talking to, as well as hear them, when they are engaged in a telephone call.

A video telephony terminal is a device, which is capable of providing a user with information in image format in conjunction with audio data and/or text.

A video telephony terminal can be used on a variety of different networks that are capable of carrying video signals and work with a number of protocols (including H320 signals, H323 signals, H324 signals, etc.). One such network is the Integrated Services Digital Network (ISDN) which has been adopted in the telecommunications industry as the next generation network. ISDN offers higher bandwidth than conventional (twisted pair) telephone lines and so H320 offers superior performance to H324. Such higher bandwidth is necessary for low interference video transmission. The increased adoption of ISDN has accordingly resulted in an increased interest in video telephony.

Video communication systems are a powerful communication tool, with applications extending far beyond simple personal calls between users. An architect, for example, might use a video communication system to show a user changes to plans whilst they are being made. Further, some call centres now answer customers'questions by providing product information and support using both sound and images.

As well as simple two-way video telephony, video

communication systems enable video conferencing in which three or more remote video terminals are in simultaneous communication. Each conference participant usually dials in to a video conferencing provider, where specialized switching equipment redistributes the image and sound data to all participants in the conference. Each participant is able to see and hear all the other participants. Increasingly projects within companies are being developed across separate corporate sites, and those involved in such projects have to deal with colleagues with whom they cannot regularly meet. Video conferencing in business is thus a rapidly expanding application of video communication systems.

There are also many applications for video communication for disabled people. Perhaps the most obvious is the advantages that it offers to people who have impaired hearing and use lip reading and/or sign language as their preferred mode of communication.

There are still more applications, e. g. as support for elderly and home-bound people whose quality of life has been shown to improve when they get access to video telephony ; and in medicine where opportunities for remote diagnosis are being developed. Indeed, there are applications for people who are visually impaired. In these cases, video communication can be used as a"remote eye"or, in case of partial sight, as an enhancing medium in remote education.

For most video applications a user (sometimes referred to as a subscriber) communicates via a"remote terminal"such as a video phone, or via a personal computer with suitable software and camera hardware.

The choice depends on the situation, i. e., the practical application, available space, cost etc. A remote terminal is often more user-friendly, whereas a personal computer may offer greater flexibility.

The cost of video telephony and video conferencing remains high, partly due to the relatively high line rental cost of ISDN as compared to line rental costs for conventional telephone lines. Accordingly, take-up levels have been relatively low, particularly in the small and medium

enterprise (SME) sector and the domestic sector. Providers of video communication systems are therefore interested in ways of increasing revenue from their services through the use of advertising and information services.

United States Patent No. 6,084,628 describes a system and method of providing targeted advertising during video telephone calls. The system includes a centralised database of subscriber advertising preferences, and an information source containing advertisements for use in the system. When users of the system are engaged in a video telephone call, the user's terminal retrieves the advertising preferences for that calling subscriber from the database and then retrieves advertisements, relevant to the subscriber's preferences, from the information source. The advertisements are displayed in a window on the calling subscriber's display screen. The advertisements are displayed whilst the users talk to one another by means of their video phones, which can be intrusive.

International Patent Application No. WO 98/56154 describes a voice-only telephone system for delivering promotional messages to telephone users. This system is prompted to deliver audio advertising messages to a phone when the phone handset is first lifted and a telephone connection is being made. This can be both distracting and irritating to the calling party.

The present invention seeks to provide an improved communication system for providing display data to users of a video communication system, which is suitable for the delivery of promotional/ advertising material.

In accordance with a first aspect of the present invention, there is provided a video communication system comprising: at least two video terminals each having a video display and each being adapted to send, receive and display moving images; a display data store containing selectable display data; and, a controller for sending selected display data from the display data store to the video terminals, wherein each video

terminal includes a writable image store for storing the display data from the controller, and the controller includes a communications interface adapted to initiate a call to a video terminal for the purpose of sending selected display data to the video terminal for storage in the image store.

In accordance with a further aspect of the present invention, there is provided a video communications controller adapted for use in a video communication system, the controller including a display data store containing selectable display data and a communications interface for sending selected display data from the display data store to a video terminal, wherein the communications interface is adapted to initiate a call to a video terminal for the purpose of sending the selected display data to the video terminal.

In accordance with a further aspect of the present invention, there is provided a method of updating a video terminal in a video communication system, having a writable image store, with replacement display data comprising sending from a controller over the communications network display data selected from a store of display data and writing the selected display data to the image store of the video terminal the improvement being the controller initiates the call to the video terminal for the purposes of updating the video terminal.

With the invention, the uploading of replacement display data, for example a new advertisement, is controlled by the controller. The terminal does not prompt the uploading of the selected display data and ensures that the subscriber does not incur the cost of the call when a new advertisement, for example, is being uploaded. More preferably still, the display data is updated in the display data store by the controller on an overnight basis when the terminal is most likely not to be in use.

Alternatively, display data may be updated by the network provider during the course of the working day. In this way, a number of advertisements may be rotated on the system by the network provider.

It is to be understood that the term"display data"referred to

herein may be, but is not limited to, image data, whether still or moving, or text data. The image or text data may have audio data associated with it.

The display may be any suitable means for viewing images, for example a screen or monitor.

In accordance with a further aspect of the present invention, there is provided a video terminal having an image capture device; a video display; a communication interface for sending to and receiving from a communications network moving images for display on the video display; and, an image store for storing display data, wherein the image store is a writable image store-and includes an input for receiving replacement display data via the communications network to be stored in the image store, and the video terminal further includes a switching device for automatically switching between images received from a second video terminal via the communications network and display data in the image store, whereby the display data is only displayed on the video display when images are not being received via the communications network.

Thus, when the video terminal is in idle mode awaiting a call, the display data may be visible on the video display. In this way, actual video telephone calls are not interrupted or altered in any way by the display data and the subscriber is not distracted during a call. During a voice-only telephone call, the display data may be displayed on the video display of the terminal.

In accordance with a further aspect of the present invention, there is provided a video communication system comprising: at least two video terminals each having a video display, a user input interface and a contact data element store for storing a plurality of contact data elements in association with respective contact identification codes, and each being adapted to send, receive and display moving images; a display data store containing selectable display data; and, a controller for sending selected display data from the display data store to the video terminals, wherein the controller further includes a links manager-adapted to associate with the

selected display data a respective contact data element for sending to a video terminal and the video terminal includes a terminal communications interface for connection to the controller across a communications network, the terminal communications interface being adapted to receive from the controller the respective contact data element associated with the selected display data and to assign the respective contact data element to a predetermined contact identification code in the contact data element store of the video terminal.

In accordance with a further aspect of the present invention, there is provided a video terminal adapted for use in a video communications system, terminal having an image capture device; a video display; a contact data element store; and a terminal communication interface for connection to the video communication system, the communications interface being adapted to receive from the communication system a contact data element associated with selected display data and to assign the contact data element to a predetermined contact identification code in the contact data element store.

In accordance with a further aspect of the present invention, there is provided a method of updating a video terminal in a video communication system, having a contact data element store for storing a plurality of contact data elements in association with respective contact identification codes and a terminal communication interface for communicating with a controller via a communications network, the method comprising associating with selected display data a respective contact data element; identifying by means of the terminal communications interface the respective contact data element; and assigning the respective contact data element to a predetermined contact identification code in the contact data element store of the video terminal.

Accordingly, when a particular advertisement is uploaded, it is immediately assigned a predetermined identification code which in the case of a standard video phone would be a speed dial entry, for example,"0".

This cannot be altered by the user of the remote terminal. When a user, interested in an advertisement that is displayed on the video display of their terminal, wishes to contact the group or organisation identified in the advertisement, the user need only press the relevant keys on the keypad to select the relevant entry in the subscriber terminal address book.

The contact identifiers are, in the case of a telephone network, the telephone numbers of individuals or organisations which are stored in the local memory on the video terminal. In the case of communication via the internet, it will be appreciated that the contact identifiers will be in the form of URLs, email addresses, IP addresses, or other unique terminal identifiers.

In accordance with a further aspect of the present invention there is provided a video communication system comprising: a video terminal having an image store and being adapted to send, receive and display moving images; a display data store containing selectable display data; and, a controller for sending selected display data from the display data store to the video terminal, wherein the video terminal includes a terminal communications interface for connection to the controller across a communications network, the communications interface being adapted to authenticate the controller and enable storage of the selected display data sent by the controller in the image store.

In accordance with a further aspect of the present invention there is provided a method of updating a video terminal in a video communication system, the video terminal having a display data store and a terminal communications interface, the method comprising: sending from a controller of the video communication system selected display data to the video terminal, and authenticating the controller prior to storing the selected display data in the image store.

The display data may be sent from the controller to a video terminal in either compressed or non-compressed format. Communication between the elements of the system may be via cable, ISDN, or satellite,

but is not limited to this list.

In a preferred embodiment, the communication system further includes a subscriber address book, which contains the telephone numbers or other unique identifiers of each of the video terminals.

The server may be a conventional personal computer.

However, if more memory is required than is generally available with a personal computer, the server may consist of a network of personal computers or a bespoke system. Preferably, the network used for communication between individual video terminals and between the controller and each of the video terminals is the Integrated Services Digital Network ISDN).

The various aspects of the invention will now be further described, by way of example only, with reference to the accompanying drawings in which like numerals are employed to identify like components.

Figure 1 is a schematic diagram of a video communication system illustrating features of the present invention; and Figure 2 is a flow diagram of the operation of the video communication system of Figure 1.

In the following description of the video communication system reference is made to the display of advertisements. It will be immediately apparent that the functionality of the video communication system is greater than this and that the advertisements are only one form of display data that may be communicated through the system and displayed on a subscriber's terminal. The display data may be any form of images, moving or still, or text and may be in conjunction with audio data.

Moreover, the display data may be informational rather than commercial in nature.

With reference to Figure 1, a video terminal 1, which may be a video phone, has an image capture device 2 in the form of a camera positioned so as to be able to record video images of a user facing the terminal 1. The terminal also has an image store 3 being a memory in

which picture data is held, a switching device 4, a communications interface 5 and a video display 6 which preferably is a flat screen display such as an LCD or plasma screen. The image store 3 contains picture data for an advertisement that is intended for display on the video display 6 when the terminal is not being used for a video call. The communications interface 5 facilitates the receiving and sending of video data via a communications network 10 to which the terminal connects and for the receiving of new advertisements. The video display 6 displays video data received from other remote video terminals via the communications network as well as advertisements stored in the image store 3.

The switching device 4, which may be implemented in software, activates and deactivates the display of advertisements on the video display 6 depending upon whether the video terminal is in"Video Call"mode. The deactivation of the advertisement display is triggered when the terminal goes into Video Call mode as a result of video images being received from a second remote video terminal. As mentioned earlier, the display data store 3 contains image data for an advertisement to be displayed on the screen 6 of the video terminal. When the terminal is in "User"mode (e. g. idle mode) the switching device 4 is enabled (the"On" state) and the image data is read from the display data store 3 so that the advertisement can be displayed on the screen 6. When a call from another video terminal is made to the terminal 1, the terminal determines whether the call is audio only or is a video call and where the call is a video call the terminal enters Video Call mode. Where a video call is detected the communications interface 5 signals this to the switching device 4 which is then disabled (the"Off"state). When the switching device 4 is disabled, the buffer (not illustrated) to the screen 6 is cleared to receive image call data from the communications interface 5. The switching device 4 is only enabled when no images are being received from another remote terminal 1. When a replacement advertisement is being received the current advertisement is retained on the screen until the new advertisement has

been received and stored successfully. The switching device 4 need not be disabled by receipt of a call from the controller 16, although in certain implementations this may be preferred.

The video communication system is indicated generally by reference numeral 7. The system 7 has a plurality of remote individual video terminals of which two 1 a, 1 b are illustrated in Figure 1. As mentioned above, the video terminals communicate with each other via a communication network 10 which is preferably an ISDN but may be any other form of communications network capable of carrying video signals.

The communication network 10 is conventional in construction and has a network control 8 and ISDN lines 9, connecting each of the elements of the communication system 7 together.

The system 7 also has a display data store 11, which stores advertisements to be selectively sent to one or more individual video terminals 1. In the display data store 11 the advertisements are most conveniently stored in writable memory (e. g. RAM), in one or more tables with associated unique advertisement ID codes. The display data store 11 includes a data input port 20 for receiving replacement/additional advertisements for storage in the display data store 11.

A subscriber address book 14 is also part of the communication system 7 and contains the telephone numbers of individual terminals 1 to which advertisements from the display data store 11 are to be sent. In a similar manner to the display data store 11, the telephone numbers are stored in a writable memory (e. g. RAM) with associated unique subscriber ID codes.

The communication system 7 includes a controller 16 which has an ISDN interface 12 by means of which the controller 16 communicates with other elements of the system 7 via the ISDN lines 9 of the network 10. The controller 16 is the server for the advertising communication system 7 and communicates with the video terminals using a communication protocol. The protocol is extensible and allows media

clips, such as advertisements, to be sent from the controller 16 to the video terminal 1. Additionally, all attributes of the video terminal can be remotely configured by the controller 16 via the protocol.

The controller 16 includes a header generator 13 which may be implemented in hardware/software or a combination of the two. The header generator 13 selectively accesses image data for individual advertisements from the image store 11, by means of the advertisement ID code. The header generator 13 then generates a header to be attached to the selected image data prior to the image data with its header being sent, via the ISDN interface 12, to a remote video terminal. Although reference is made to a header generator it will be apparent that this is simply one embodiment of the protocol employed to transfer instructions and data from the controller to the remote terminals. Details on the protocol are set out in greater detail below.

In the version of the communication system illustrated in Figure 1, the system 7 additionally includes a scheduler 15 which supplies instructions to the controller 16 concerning the advertisements to be uploaded to individual remote terminals. For example, the information supplied by the scheduler 15 to the controller 16 may be in the form of a relational table of subscriber ID codes and advertisement ID codes. The controller 16 then implements the instructions contained in the relational table to the extent that for each subscriber ID code appearing in the table the advertisement associated with the tabulated advertisement ID code, or codes, is issued via the network 10 to the remote terminal for that subscriber. For example, the relational table may contain an entry relating subscriber ID code XX to the advertisement ID code YY and separately an entry relating subscriber ID code AA to the advertisement ID code BB. This then instructs the controller 16 to send the image data for the advertisement YY to the remote terminal having the telephone number associated with subscriber code XX and the image data for the advertisement BB to another remote terminal having the telephone number

associated with subscriber ID code AA. Thus, the scheduler 15 issues instructions to the controller 16 for the uploading of different advertisements to different subscribers. This process is wholly automatic following generation of the relational table and may involve all or only some of the subscriber ID codes and the advertisement ID codes. In this way, the scheduler via the controller 16 (under the control of a network provider, for example) dictates which advertisements are displayed on individual video terminals. The terminals are not configured to permit user selection of advertisements.

The instructions issued by the scheduler 15 may also include instructions as to the timing of the uploading of the advertisements to the individual remote video terminals by the controller 16. Alternatively, the timing of the upload to the remote terminals is performed at predetermined regular intervals programmed into the controller 16. For example, the upload is preferably performed every 24 hours during the night, so as to minimise inconvenience to the subscribers and to avoid the remote terminals being in use when the upload is initiated by the controller 16. It will, of course, be apparent that the upload of an advertisement to a remote terminal may be performed at any time when the video terminal is not in use with a telephone call.

The selection of advertisements for individual subscribers may be performed manually or may be determined automatically using conventional statistical analysis techniques (such as that described in US 6,084,628) which may take into account factors such as the subscriber's geography, age, income, occupation, marital/familial status, hobbies, etc.

In addition, the scheduler 15 is in communication with the display data store 11 and the subscriber phone book 14 and respectively supplies image data for new advertisements and the telephone numbers of new subscribers for inclusion in the tables of these two memories.

The video terminals 1 also include a user input interface most commonly in the form of a keypad 17. The keypad 17 is used in the normal

manner to'dial'a telephone number to initiate a call connecting the video terminal to a second video terminal. Alternatively, the telephone number of the second video terminal may be stored in a local memory 21 containing regularly used phone numbers. Each phone number stored in the local memory has associated with it a dialling code, commonly referred to as a speed dial number, so that a user may dial the speed dial code or in some other manner select the speed dial code so that the terminal automatically seeks connection with a terminal having the phone number associated with the selected speed dial code. In this way the user avoids the need to repeatedly dial commonly used phone numbers. With the communication system 7 described herein, one of the speed dial codes is not available for assignment by the subscriber. Instead, the speed dial code, preferably code"0", is reserved for phone numbers supplied by the controller 16 to the video terminal 1.

Where a phone number is supplied by the controller 16, it is a telephone number relating to the advertisement being uploaded to the terminal i. e. the telephone number of the organisation or company being advertised. This phone number is added, by the header generator 13, to the header information which is attached to the image data for uploading to the video terminal 1. The header information is analysed by the communications interface 5 of the video terminal 1 as it is received during "Upload"mode. Where a phone number has been incorporated into the header, the communications interface 5 strips out the phone number and automatically assigns the phone number to the reserved speed dial code.

This enables the same speed dial code, e. g."0", to be used for the individual phone number of whichever advertisement is currently stored and displayed on the screen 6 of the video terminal.

Although reference has been made to only one advertisement being stored in the display data store 11, it will be apparent that display data for more than one advertisement may be stored in which case the different advertisements may be displayed on the screen 6 of the terminal

sequentially or simultaneously. In these circumstances, the phone numbers associated with each advertisement are stored separately from the local memory 21 of phone numbers and are written to the reserved speed dial code of the local memory only when the relevant advertisement is being displayed on the screen.

As data is uploaded from the controller 16 to the video terminal 1 it is important to ensure that this access to the video terminal is not abused. Therefore, security measures are required to prevent unauthorised access of the video terminal and to authenticate all external access of the remote terminal for the purposes of uploading instructions and data. The security measures may take various forms a few of which are described below.

Two examples of a controller hardware specification are :- Minimum specification Pentium Class CPU running at 200MHz or more 16MB Ram 200MB of Hard Disk Motion Media PCI ISDN card (model number 801) ISDN 2e telephone line This specification is adequate for 100 advertisements in the form of display data being uploaded to 1000 terminals.

High Performance specification Pentium III Class CPU running at 500MHz or more 128MB Ram 20GB Hard Disk 5 x Motion Media PCI ISDN card (model number 801) 5 ISDN 2e telephone lines This specification is adequate for 5000 advertisements in the form of display data being uploaded to 10000 terminals.

The"Upload"mode is illustrated in Figure 2 in which advertisements, in the form of display data, are sent from the display data store 11 to the remote video terminals 1. In the Upload mode, on the basis of the relational table supplied by the scheduler 15, the controller 16 initiates the Upload process by dialling the telephone number of the first subscriber listed in the relational table (Step 1). The video terminal on that telephone number identifies the call as emanating from the controller 16, and answers the call (Step 2). Preferably, the terminal answers the call from the controller 16 in silent mode so that the user of the terminal is not disturbed unnecessarily and this also avoids the user attempting to answer the call. The authentication of the controller 16 is then carried out prior to any instructions or data being uploaded to the video terminal (Step 3).

Suitable security procedures are described in greater detail later.

The video terminal 1 then confirms to the controller 16 the protocol version that the video terminal is one which it is programmed to recognise (Step 4). On the basis of this information, the controller 16 selects the relevant communications protocol (Step 5) and sends the header information, including any telephone number to be added to the reserved speed dial code (Step 6), and this starts the upload process at the terminal (Step 7). A message confirming that an Upload procedure is taking place is then displayed on the terminal screen. The controller 16 subsequently sends to the video terminal 1 display data embodying a media clip which may be a static pictorial advertisement or a sequence of images with/without sound and/or text for a non-static advertisement (Step 8) which is saved to the image store 3 (Step 9).

Once the transfer of display data to the video terminal 1 is completed, the video terminal confirms to the controller 16 whether the advertisement has been successfully uploaded (Step 10). If the advertisement has been successfully stored in the image store 3, then a successful Upload is confirmed to the controller 16 (Step 11). On receipt of this confirmation the controller 16 disconnects from the video terminal (Step

12) and the video terminal 1 also hangs up (Step 16). If, however, the advertisement has not been successfully stored in the image store 3, then the controller 16 is advised by the video terminal 1 that Upload has been unsuccessful (Step 13). The failed Upload is logged by the controller 16 (Step 14) and the video terminal may display the previous advertisement or a default advertisement (Step 15). Thereafter, both the controller 16 and the video terminal disconnect from one another (Steps 12 and 17).

In the event the video terminal is in use, without power or, in error, the user switches off the video terminal 1 during the Upload procedure, the connection between the controller 16 cannot be established or is broken and the controller 16 logs the Upload as having failed (Step 14). The video terminal 1 remains available during the upload procedure for outgoing calls so that calls to emergency numbers, for example, may be made.

This Upload procedure is then repeated for each of the subscribers listed in the relational table with in each case a selected advertisement selected from a collection of different advertisements stored in the display data store 11 being Uploaded.

Once all subscribers listed in the relational table have been called, the controller 16 analyses the log of failed Uploads and re-tries, a predetermined number of times, the Upload (Step 18). If all further attempts fail, the controller 16 logs the complete failure of the Upload and may generate an error report listing these failures.

Various methods for authenticating the authority of the controller 16 to upload data and instructions to the video terminal 1 may be employed. The following are non-limiting examples of such methods.

Calling Line Identifier (CLI) Matching.

The link between the controller 16 and the video terminal 1 is authenticated by the video terminal 1 analysing the CLI from the controller 16 and only accepting the call once it sees a previously agreed number or

part number.

Proprietary Call Type The link between the controller 16 and the video terminal 1 is authenticated by the video terminal 1 receiving a call type which is non- standard and pre-agreed between the video terminal 1 and the controller 16.

Password A previously agreed password authenticates the link between the controller 16 and video terminal 1 once the video terminal 1 has accepted a call from the controller 16.

Encryption Once the video terminal 1 has accepted a call from the controller 16, a correctly encrypted data stream authenticates the link between the controller 16 and the video terminal 1.

Dialback The video terminal 1 calls back the controller 16 to authenticate the link with the controller 16 on a previously agreed number, address, date, time or similar identifier. The video terminal 1 is requested to perform a call-back by a call made from the controller 16 to the video terminal 1 in which a message is passed to the video terminal 1 instructing the video terminal 1 to call the controller 16 via the Communication Protocol.

An example of a protocol used to upload an advertisement into a video terminal via a communications network must enable the following information/data to be supplied from the controller and accepted by the video terminal. That information consists of: subscriber identifier (a phone number or unique identifier, such as but not limited to a URL, for

example) to ensure that the correct video terminal has been contacted by the controller ; whether the data is compressed or not; display data identifier (the name of the advertisement for example this may also function as the contact name that is posted to the local memory of the terminal); a contact data element (for example a phone number or unique identifier) to be written to the reserved location in the local memory of the video terminal; the size of the display data to be transferred to the video terminal ; the format of the display data, for example CIF as defined within the H. 320 video-conferencing standard; the display data itself ; and, appropriate parity check bits.

As described above, this information and data may be transferred by means of a header that is added to the display data transferred to the video terminal. However, this is only one means by which the relevant information and data may be transferred. Alternative procedures, well known in communication networks, may be employed to implement the protocol. Upon receipt of the information/data, it is preferred that the video terminal provides a response acknowledging receipt in order to indicate success or failure, as described earlier.

As can be seen from the above, the present invention provides a video communication system which has advantages not previously available. The communication system enables the network provider, or whomsoever has management of the communication system, to raise revenue by way of advertisement without the advertisements being intrusive to the user of a video terminal. In this respect the advertisement is only visible when the terminal is in idle mode and is not visible when engaged in a video call. Furthermore, the selection of advertisements for an individual video terminal is decided by the manager of the communications system and not by the user of the terminal. In this respect the uploading of an advertisement to a video terminal is instigated by the controller of the communications system rather than the terminal. This presents security issues which are addressed by ensuring that the video

terminal authenticates the controller before accepting data and instructions from the controller. Additionally, the communication system provides a means for updating the video terminal's own phone book so that a reserved speed dial code is assigned the telephone number of whichever organisation currently has an advertisement displayed on the screen of the terminal.

The present invention is not limited to the particular features of the communication systems above. Elements of the communication system may be omitted or altered and the scope of the invention is to be understood from the appended claims.