Mobile TV: The difference between unicast and broadcast

The definition of the terms broadcast and unicast justifies the interest of implementing the DVB-H standard for Personal Digital Television (PDT) when compared to current Mobile TV offers. Mobile TV has already been in existence for a number of years on mobile networks, but the broadcast in DVB-H (Digital Video Broadcast – Handheld) should allow it to overcome certain constraints.

Mobile TV on 3G networks presents limited offerings due to the bandwidth constraints on the cellular network. This means that the each cell can only host a determined number of users, with each opening a channel every time. When all of the channels are occupied, it is not possible to add any new users. This is a unicast broadcast.

This form of Mobile TV can only work if the number of users remains overall low. This said, if you want the take up of Mobile TV to be large, then you need access to as many people as possible, requiring a different broadcast method.

The difference between unicast and broadcast

Broadcast corresponds to the analogue hertz transmission: an unlimited number of users can receive the stream if they have an adequate receiver and are located in the coverage zone. This form is adapted to the objective of mass take u p of PMT.

The inconvenience is that unlike the broadcasting of a unicast which uses the existing 3G cellular network and a normal 3G telephone, you need a network of transmitters to be built from zero, and then commercialise the specialised receptors.

This is why, with the attribution of channels from the CSA (Conseil Superieur de l’Audiovisuel), the coverage obligations are only 30% in the first three years after the launch of PMT, and 60% in the first six.