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VisionAIR Trials: The Common Platform

Definition of Bearer Services

Broadcast Video

The first bearer service is Broadcast Video. It refers to video streams that are sent over the (inter)network simultaneously to all users who have subscribed to this service. The server starts the streams, normally after they are announced via a program guide. Broadcast Video is typically used for live broadcasting of AV information. The AV information then is encoded and streamed live. The Broadcast Video service also is often used for a scheduled broadcast (not live), also called Near-Video-on-Demand (nVoD). The prerecorded and encoded AV information is then multicasted at a certain point in time. The user can "tune to the channel" to view the high quality video stream at the Set-Top Box or on a PC using a compliant software player.

At the server side a continuous channel must be present, which could be a channel captured from cable TV, from satellite or from other (real-time) encoded sources.

Video-on-Demand

The second bearer service is Video-on-Demand (VoD). With VoD the user can start receiving a video stream at anytime. Each user receives a separate stream, started at his or her request. Other terms often used for this service are delay-TV or time-shifted TV, since the AV material was recorded and encoded at an earlier stage. The user can view the high quality video stream at the Set-Top Box or on a PC using a compliant software player. This bearer service implements such as starting, stopping and skipping through the video content.

At the server side it is possible to create video files and store them for VoD. A digital video camera input and an analog video input are possible.

Telephony

The telephony bearer service implements call setup, release and forwarding capabilities between Internet telephony clients. Additionally, connections can be made to and from telephones connected to the normal telephone network (PSTN) via a VoIP gateway. It furthermore implements an answering machine function, a way to retrieve voicemails, and the possibility of initiating conference calls.

Video Conferencing

The videoconferencing service enables videoconferencing between end-users on top of the telephony bearer service. So the end-users will be able to hear and see each other simultaneously while using these services. This bearer service makes it possible that two end users can participate in a private videoconferencing session or that multiple end users can participate in a videoconferencing session.

Home Control

The Home Control Service allows the user to do locally and remotely the following things :

  • View the status of home appliances connected to the RG
  • Send commands to home appliances connected to the RG

In both cases the user needs to establish communication with the Residential Gateway (RG) to which the home appliances are connected. This communication can be realized via the Data or Telephony Bearer Service.

When using a Graphical User Interface (GUI) the Home Control Service messages can be sent as data via the Internet or a local Home Network connection. This can be accomplished by using a WAP-enabled mobile phone or a PC with a Web Browser. When using a Speech-Based User Interface (SUI), the Home Control Service messages use the Telephony Bearer Service and any mobile or standard phone can be used for it.

Security Service

The Security Service allows sending security related event notifications to the security server, the user's mobile phone and to the security company. Sending of an event message is triggered by a sensor of the Security Alarm System, which is connected to the Residential Gateway (RG). The Security Service also enables the user to view the status of the Security Alarm System and remotely send commands to switch it ON and OFF. These communications involve the Data Bearer Service. It is essential that all Security Service related messages arrive at their destination and that this arrival is confirmed.

Data

The data service may support various types of information being exchanged that are not further specified or even known. The data service is the bearer service that supports these services and can be thought of as the most basic service available. As such, it can also be regarded as the supporting service for the other bearer services.

The data service includes a method to send a data message to multiple destinations. It also allows prioritization of data messages by dividing them into separate classes. It is an unreliable service, which means that no confirmation is given about the actual arrival of data messages.