In this chapter, Tina Mani tells us about DVB-H technology, MBMS technology and combining satellite television with mobile.
What is Mobile Television?
Mobile Television, as the name suggests, is the ability to view regular television channels over your mobile.
Mobile Television – Broadcast – DVB-H
Traditional Television uses a broadcast medium, i.e., different channels are played out from one source and all the listeners of a channel tune in to the particular channel frequency. Keeping the same philosophy, standards like DVB-H evolved from the broadcasting world, to allow viewership on the mobile by tuning into the channel. The DVB-H technology did not take off worldwide mainly because of the high upfront investment in infrastructure and because a separate radio network had to be built exclusively for this purpose. Also the technology was dependent on support in the handsets, which needed an additional radio. Nokia tried to solve the problem by launching a DVB-H antenna accessory that could plug into any Nokia phone and make it DVB-H enabled, but by the time they launched this, the technology was more or less dead.
In India, Doordarshan launched DVB-H on a trial basis in some areas around Akashwani Bhavan in Delhi. This service can be availed using a DVB-H compliant handset. Today, there are no DVB-H compliant handsets in the Indian market. Initially the service was not launched commercially because of lack of spectrum in the UHF band (470-862 Mhz), and a lack of understanding on how to commercialize this model. Now the Information & Broadcasting Ministry in India has already made plans to release this spectrum for auction to use for Broadband Wireless Access (LTE) instead. So this kills the DVB-H story in India.
Mobile Television – Broadcast – MBMS
Another new technology that is now being talked about is Mobile Broadcasting Multimedia Service (MBMS) which is based on cellular technologies. LTE Operators in India like Reliance Industries are running trials for this technology, because it fits well into their plans of LTE deployment with a big focus on video. It is used to bring IPTV services to the mobile, and can work very well with LTE networks. This utilizes the cellular (mobile) network. This technology is used to create the equivalent of IPTV on a mobile network. Each channel is streamed to one multicast IP address and the mobiles in that cell join that multicast group to view the channel. It requires support of MBMS technology on the base stations as well as in the core network equipment. Since each Base station (radio) is responsible for a cell, this helps optimize the bandwidth only if multiple users within that cell are viewing the same program.
Interactive Television – combining satellite television (DVB-S) with mobile
Satellite television uses a one way satellite connection to the television through a dish antenna. This means that the communication with the viewer is one-way. Hence all the users in an area get the same set of programs. To make one way medium more interactive, and personalize television more, an uplink channel from the user to the headend is required. Set top boxes with a broadband port or a wireless dongle can be used to provide this communication from the user to the head end. This can enable many interesting applications like distance learning, true Video On Demand, etc.