network also allows for the delivery of significantly more content and functionality. In a typical TV or satellite network, using broadcast video technology, all the content constantly flows downstream to each customer, and the customer switches the content at the set-top box. The customer can select from as many choices as the telecomms, cable or satellite company can stuff into the pipe flowing into the home. A switched IP network works differently. Content remains in the network, and only the content the customer selects is sent into the customer's home. That frees up bandwidth, and the customer's choice is less restricted by the size of the pipe into the home. Interactivity An IP-based platform also allows significant opportunities to make the TV viewing experience more interactive and personalised. The provider may, for example, include an interactive programme guide that allows viewers to search for content by title or actor's name, or a picture-in-picture functionality that allows them to channel surf without leaving the programme they're watching. Viewers may be able to look up a player's stats while watching a sports game or control the camera angle. They also may be able to access photos or music from their PC on their television, use a wireless phone to schedule a recording of their favourite show, or even adjust parental controls so their child can watch a documentary for a school report, while they're away from home. A feedback channel from the viewer to the provider is required for this interactivity. Terrestrial, satellite, and some cable networks for television do not feature a feedback channel and thus don't allow interactivity. However, interactivity with those networks can be possible by combining TV networks with data networks such as the Internet or a mobile communication network. Video on demand IPTV technology is used for video on demand (VoD), which permits a customer to browse an online programme or film catalogue, to watch trailers and to then select a program. The playout of the selected item starts nearly instantaneously on the customer's TV or PC. Technically, when the customer selects the program, a point-to-point unicast connection is set up between the customer's decoder (set-top box or PC) and the delivering streaming server. The signalling for the trick mode functionality (pause, slow-motion, wind/rewind etc.) may be communicated using, for instance, RTSP. In an attempt to avoid content piracy, the VoD content is usually encrypted and digital