Mobile television: the reality of rollout

For some exhibitors at this show, the business model for mobile TV is a lot simpler than for others. Take antenna systems specialist RFS, which, as Dave Thickett, RFS senior systems engineer, told the Show Daily, has experience in DVB-T, the terrestrial cousin of mobile broadcasting contender DVB-H.

In the UK, he said, a digital switchover programme is imminent leaving a number of frequencies free in the UHF band to be auctioned for various services of which DVB-H could be one: this would most likely be satellite distribution with an overlay in UHF.

“The significance for RFS,” he said,” is that for this type of overlay we would have to install an omni-directional antenna on probably one in three to one in four base stations.” Currently there are about 25,000 of these in the UK. If Italy, Spain, the US and a number of other countries follow suit, he said “we reckon Eur250 to Eur300 million a year in UHF antenna sales”.

That’s the good news for infrastructure providers. The good news for operators is that DVB-H requires lower power antennas than the terrestrial version. Typically in terrestrial broadcast the transmitter powers might be from one to 30 kilowatts. DVB-H transmitters are looking to cover smaller cell sizes, which implies the 200-500 watt range, and lower power and simpler, cheaper antennas than the terrestrial version. As Thickett said: “That’s a possible difference of Eur3000 per site for an antenna compared with a typical broadcast antenna cost of Eur150,000 – Eur500,000 per site.” And of course screen size is much smaller so data rates are much lower than terrestrial, which helps with the number of channels you can offer.

It sounds like a straightforward proposition but there could be some technical difficulties. Thickett explained: “If people decide they want to build DVB-H as a single frequency network, then there are timing issues in that all of the transmissions that overlap have to be reasonably well timed. There’s a parameter called the guard interval; if the guard interval is too great-if one signal arrives a long time after the other one-it will actually destroy the main signal. So you have to make sure all the overlaps are timed.”

The company also offers equipment for DMB, and, with Alcatel, a third system called DVB-SH, leaving it ready to take advantage of most rollout possibilities.

Which brings us back to the simple business model for antenna providers. How to sell these services to the end user may be undetermined but rollout is happening, no matter what. Or, as Thickett puts it: “Once the results are in from the trials and operators have analysed them and decided which is the system to go for, everybody will roll it out; the only question now is which system is going to be the most cost-effective way to do it.”