Mobile TV

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Mobile TV (Cellevision in the USA) is a name used to describe a service to subscribers via mobile telecommunications networks, most probably the cellular phone carriers. South Korea is at the forefront of this developing sector and BT in the United Kingdom is the first company outside Korea to implement Mobile TV.

Technically, there are several possibilities. These include digital video broadcast-handheld (DVB-H), digital multimedia broadcasting (DMB), TDtv (based on TD-CDMA technology from [IPWireless]), 1seg (based on Japan's ISDB-T) and MediaFLO. None is ideal as all have drawbacks of one kind or another: spectral frequencies used or needed, signal strength required, new antennas and towers, network capacity required, or business model.

There is no new unified global spectrum available for this service, whichever approach is chosen. Perhaps the most plausible is TDtv, which is part of the 3GPP Release 6 specification and is fully UMTS. It also has the advantage of being an 'overlay' on existing spectrum and so can possibly allow roaming from jurisdiction to jurisdiction. And handoff between nodes will be clearly feasible, even at relatively high speeds (eg, in the low hundreds of kilometers/hour).

As of early 2006, cellular carriers have begun several experimental projects to test several of these approaches. By the end of 2006, most observers expect that some approaches will have been dropped, and one or more to have emerged as possible standards.

There is also on-demand uni-cast streaming of mobile TV via 2.5G GPRS and 3G. However, less than 5% of the 2.3 billion handsets in use worldwide are connected to a 3G service and there are limitations to bandwidth capacity - and therefore to the number of viewers at any one time - with 3G. New compression technologies allow for on-demand streaming of TV channels over mass-market GPRS.

Recent research suggests that people will only be prepared to pay a token amount to receive full-length broadcast TV on their mobiles as typical mobile TV viewing patterns are just 3 minutes at a time. People seem far more prepared to pay to receive content on-demand - over 2.5G GPRS.

[edit] Trademark

Cellivision is a registered trademark of WHDC LLC, USPTO Registration #3099426 in the class of goods and services Streaming of video material on the Internet. Similar variants of the registered trademark (e.g. Cellevision) may also be subject to restricted use.