Prior Art Discussion Like USSD and SMS, CBC is currently available as standard in many GSM handsets. But unlike SMS (and like USSD) CBC has failed to generate a significant market for it's capabilities. This also applies to other broadcast protocols such as the ANSI-41"Broadcast Messaging"protocol.

In GSM, CBC provides 1000 (100 reserved by GSM) channels for pushing information down to a mobile device. To access a channel the subscriber must be aware of its existence and also be able to activate this on their handset. This involves some difficult traversing of menus on the mobile device. When information is received on the handset it is displayed in a mobile device vender specific way, not providing a common"look and feel".

CBC provides the following capabilities to content providers: 900 Distinct Channels 1000 separate channels are defined for use by the CBC. The first 100 (0-99) have been reserved. The remaining 900 can be defined on a per operator basis.

Standard on all GSM mobile devices Like SMS, current handsets support CBC. However, the method in which the information is presented on the mobile device is proprietary.

SMPP Type Interface (BMSP-Broadcast Message Submission Protocol) CBC provides a BMSP (similar to SMPP v3.4) interface. External applications can use this interface to push information to mobile devices.

'Message Size A CBC message has 93 7-bit characters by 15 pages (1,395 7 bit characters).

Asian languages use Unicode which is a 16 bit character set, and this will reduce the amount that can be displayed accordingly.

Message Types The CBC supports two message types: Express Messaging The message is pushed through the CBC to the mobile device where it is only displayed for a configurable period. After this time the mobile device removes the message.

Time Based Messaging The message is continually broadcast by the CBC for a period defined within the CBC-specific message header. This messages can be defined as either "PLMN Wide"or"Cell Wide"."PLMN Wide"means that the mobile device will only receive the message once in the network,"Cell Wide"means that the mobile device will receive the message each time it enters a new cell.

Channel Scanning Some mobile devices can activate more then one CBC channel at a time.

The CBC messaging as it exists today has the following limitations: Proprietary Interface/Not Internet Enabled The CBC provides an interface (BMSP) that is not easily usable by content providers. Limitations include learning a specific protocol and the need for a physical TCP connection to the platform. With most operators trying to bring

the internet to their subscribers, the CBC is lagging behind other initiatives. A recent development is that the current CBC includes a Web interface using HTTP Post to a web server. The web server converts this to BMSP and sends it to the CBC. The webpage uses HTML forms.

Poor User Experience CBC protocols provide no easy way for the subscriber to choose channels and also no defined standard way of displaying information. This leaves most subscribers unable to provision themselves for information, and content providers unable to ensure the content is displayed in a meaningful manner.

The invention is directed towards addressing these problems.

SUMMARY OF THE INVENTION According to the invention, there is provided a method of providing content on a screen of a user device, in which the content is broadcast by a broadcast means characterised in that, the user device displays the content in a portion of the screen while leaving the remainder of the screen free for other device uses.

In one embodiment, the content is scrolled across the portion of the screen.

In another embodiment, the content is scrolled at a speed configured by the user.

In a further embodiment, the invention comprises the further steps of the user device generating a user menu on the basis of available content independently of the underlying broadcast channels being used to receive the content such that underlying channel usage is transparent to the user.

In one embodiment, the broadcast means includes in a selected channel an index of content in the other channels, and the user device generates the menu according to said index.

In another embodiment, the index is encoded in a mark-up language.

In a further embodiment, the mark-up language is XML.

In one embodiment, the broadcast means encodes the content in the channels in mark-up language.

In another embodiment, the broadcast means multiplexes multiple content streams in a single channel and the user device de-multiplexes the streams.

In a further embodiment, the content is generated by a push initiator which pushes the content in messages to a content manager, and the content manager re-formats the content in a mark-up language for the broadcast means.

In one embodiment, the content manager selects one of a plurality of broadcast means.

In another embodiment, the content manager routes the content to a particular wide area network address, and a broadcast means at that address broadcasts the content.

In a further embodiment, the broadcast means comprises a WLAN access point, and the content is broadcast in a wireless local area network.

In one embodiment, the push initiator generates the message with a control entity, a content entity, and a capabilities entity.

In another embodiment, the push initiator includes a default scrolling speed parameter value in the content entity.

In a further embodiment, some broadcast content is encrypted and is decrypted by the user device.

In one embodiment, the user device decrypts the content using a decryption key received independently of the broadcast.

In another aspect, the invention provides a user device comprising means for performing user device operations of a method as defined above.

In a further aspect, the invention provides a content manager comprising means for performing content manager operations of a method as defined above.

Detailed Description of the Invention The invention will be more clearly understood from the following description of some embodiments thereof, given by way of example only with reference to the accompanying drawings in which:- Fig. 1 is a diagrammatic representation of systems involved in routing broadcast content in accordance with the invention ; Fig. 2 is a representation of information entities of a pushed PAP message; Fig. 3 is a pair of images of a mobile device screen displaying received broadcast content;

Fig. 4 is a diagrammatic representation of the systems involved in routing CBC/broadcast content in a 3G network; and Fig. 5 is a diagrammatic representation of the systems involved in routing broadcast content to a fixed IP domain comprising WLAN Hotspots.

Description of the Embodiments Referring to Fig. 1 a push initiator (PI) 1 provides content. This is pushed in messages to a content manager 2. The content manager 2 selects a CBC 3 or an SMSC 4 to broadcast to a mobile device 5 in a PLMN network.

The push initiator 1 uses a Push Access Protocol (PAP) message 10 to push the content, the format of such a message being shown in Fig. 2.

Referring now to Fig. 3, the mobile device 5 is shown at two stages with two streams of content scrolling from right to left. The content does not affect the display for other operations of the mobile device. The information is displayed on the handset without user interaction other than selection of content. This allows the network to continually update this information, ensuring that the handset is always showing the latest version.

The push initiator 1 uses the following message types.

Submit a time-based push message for onward delivery to a (CBC) stream.

This message has a defined lifetime (start time/end time) associated with it.

When a new message is submitted to the same stream, the old message is automatically overwritten.

Submit an express push message for onward delivery to a (CBC) stream.

This message will only be displayed for a brief period. When this period is over, the previous time-based message will again be pushed down the stream to the mobile device.

Update a time-based push message. The message may be loaded in a broadcast server broadcasting in the PLMN or in a fixed domain. This message will enable the message content and broadcast area/destination to be modified.

Query the status of a previously submitted push message.

Cancel a previously submitted push message.

The following describes the XML tags that are supported.

PAP Message Format As shown in Fig. 2, the message 10 which is pushed to the content manager comprises three entities namely control, content, and capabilities entities. Each entity contains information relating to a specific area of message handling. A brief description of the type of information which each entity contains is presented below.

Control entity The control entity contains information relating to the type of PAP message being delivered. For example, when the push initiator is sending a PAP message of type"time-based"push-message, the control entity is used to indicate delivery information. The push initiator uses the control entity to specify the delivery stream, and to define the stream name and the delivery time constraints. Using this information, the content entity information is deliverable to the mobile stream. The control entity is an XML document of which the document type definition is defined in [PushPAP]. More tags may need to be defined.

Content entity

The content entity contains the information which the push initiator wants to deliver to the mobile client.

Capabilities entity The capabilities entity contains information about the capabilities which the push initiator expects the mobile device to support.

Every PAP message must contain a control entity. For PAP messages with more than one entity, the control entity must be the first entity in the message, followed by the content entity and the capabilities entity.

The following is an example of the content entity: Stream Name Enabled mobile devices will provide an interface for subscribers to choose a channel to be displayed on the handset. By defining the name of the stream in the message, the operator can reassign CBC streams without affecting the handset menus.

Stream Type The Stream Type provides information about the content that is available on the stream. The stream type information may include type of content, language, subscription-necessary flag, content provider, or cost.

Subject Heading This field relates to the particular heading for this message. For example on a sports channel, this heading could be set to"Spanish League". for particular football results.

Information Scrolling Speed This will be the default recommended speed that the information would be scrolled across the mobile device. Options could include teletext type display, or smooth

scrolling at different speeds. This default speed can be over-written by a local setting in the user device.

Background Colour This will be the recommended background colour for the message.

Message Information Information is made up of the following: Text Message being displayed, this is in an XML format and is inter-mixed with defined"Display Options".

Display Options This will grow as mobile devices become more advanced. They could include font size, font type, colour, speed pause (stops the current text on the screen for a period), bold, italic, flash and other options.

Channel Indexing/Directory To ensure inter-operability for handsets operating on different operator networks a consistent management of channels is desirable. If the 900 available channels are further slit by X, the mobile device would take too long to scan them all to build a user menu of available channels. A simple solution is to use channel 999 as a content index for the other channels, in which XML messages sent on this channel describe content in all the other channels. An example of the information that could be sent is a list of index channels which could be split into"business","news", "sport","travel", and"local information". The XML messages of channel 999 may also define service information channels that are currently in use for broadcasting, roaming channels that broadcast information from other networks (set up with agreement between operators), and other channels that are defined in the future, and

could include handset application upgrade channels for example. The user device uses the channel 999 index to generate a user menu on the basis of content, not the underlying channels being used. Thus, the user is decoupled from the underlying channel technology and does not need to know anything about it. He or she simply selects desired content, and it is scrolled across the bottom of the screen.

The user interface may include information about premium services available to the subscriber. For example stock information 15 minutes old could be offered free by the operator, but for a premium subscriber a live feed may be offered. Some SMS interaction may be required for transmission of BC) when de-cryption keys to the browser from the content manager.

The number of channels available for pushing different streams is limited to 900.

Using browser technology and message identification it is possible to push more then one information service on a single CBC channel. The CBC could have a repeating set of messages for a channel, with the browser only displaying the messages for the chosen information service.

By increasing the number of information services that can be displayed the operator can introduce international channels or channels reserved to provide consistent home information to roaming subscribers. Operators could assign ranges of channels to roaming partners without limiting the amount of information services they can provide.

As the push initiator on the internet has a server address it can ensure that its information will be available in other compliant networks. Subscribers roaming will receive their home service in other countries. Local information such as traffic information should not be available in an internationally defined stream.

With screen sizes increasing, a subscriber may wish for more then a single channel to be displayed. An example of this would be a stockbroker wishing to receive information about stocks on different markets.

Different subscribers can read at different scrolling speeds, configurable by the user.

A channel keyword scanning facility allows the mobile device to automatically change channel when a specific keyword appears on another stream. An example of this is a user wishing to change to a sports channel when their team is mentioned, or changing to a news channel as election or budget results are being broadcast.

The invention provides the capability of providing premium services (i. e. information content delivery) on a subscription basis. There are two methods for delivery of user subscription specific information.

1. The first is the use of SMS Messages that are scrolled on the screen giving the same look and feel as the broadcast delivery. This method of delivery would be utilised for smaller numbers of subscribers when the information being pushed does not change frequently (for example this method would not be used for sending constant stock market indexes).

2. When information is to be sent to a large subscriber base on a frequent basis the CBC is the preferred choice. In this scenario the CBC is used as a simple PLMN wide bearer technology. To provide subscription to open channels some encryption of data will be required.

The content manager encrypts information for subscription channels. The handset decrypts the signals in a manner analogous to television channel reception. The decryption algorithm on the handset is updated regularly, as provisioned over-the-air by the content manager. Keys for unlocking channels are received via SMS.

While the above describes the broadcast of content in the PLMN domain, the invention is not restricted to the PLMN Domain, and may be applied in fixed IP domains such as WLAN Hotspots. In one embodiment, the broadcast server broadcasts content to a WLAN Hotspot base-station that is labelled (i. e. with geographic longitude/latitude) and the WLAN base-station'broadcasts'the content to the WLAN users using a designated port and/or IP address. There may also be content broadcast into pico-cells, where the pico-cell may range from 100 metres to 5 metres.

Fig. 4 illustrates broadcast of content in 3G networks. As described above a push initiator 20 in the internet 21 pushes content to a content manager 22. This in turn pushes it to either an SMSC 23 or to a 3G broadcast server 24. The server 24 in turn pushes it to a Radio Access Node (RAN) using TCP/IP as the transport protocol.

The 3G air interface is significantly different and the broadcast channel may also be able to support greater payload lengths.

Broadcast of content into the fixed IP domain is illustrated in Fig 5 and like parts are given the same reference numerals. This embodiment illustrates the broadcast of content locally into WLAN Hotspots. A broadcast server 30 routes content to WLAN base-stations 31 using the IP addresses, which in turn broadcast within the WLAN area-fixed PC 32 or mobile PDA/Pocket PC 33 users. Thus, the broadcast server can intelligently select local areas for particular content. For example content may be broadcast only in the vicinity of a train station, departure lounge, or a café for example.

The broadcast of content into regions supported by different technologies will have an impact on the content payload length supported. In general, the length of the broadcast content is determined by the underlying communication transport capabilities. The length of the broadcast content payload can be significantly larger when broadcasting content into the IP fixed domain (or 3G network) as opposed to

broadcasting into the (2+G) PLMN Domain. The increased content length will enable additional broadcast services such as multimedia data formats (for example football highlights) may be contained in the broadcast. The broadcast server will manage the content encoding/service delivery to the destination base stations. The broadcast server will differentiate the service to PLMN broadcast users and fixed IP domain users using a number of techniques such as destination address format and/or, geographic domain/co-ordinates.

Broadcasting of messages in the IP Domain may use a dual IP address technique where the base station will broadcast messages to a standard IP address (e. g. IP4- 255.255. 255.255)-in this case every UA device will have effectively two IP addresses-one for point-to-point service and one for broadcast. The broadcast service may use a'well known'port and the UA will read the port at regular intervals.

It will be appreciated that the invention provides for much more widespread use of broadcast content to the benefit of both the user and the operator. The user can view the content in a non-intrusive manner without affecting other device usage such as sending or receiving voice calls or SMS messages. Also, the user can easily select desired content without needing to know anything about CBC or other underlying technology. The device couples the selected content to the relevant channels. Also, use of XML allows a single channel for optimum use of available bandwidth.

The invention is not limited to the embodiments described but may be varied in construction and detail.