By Jim Baker

For years, audio-visual entertainment on public transportation was often limited to long-haul journeys and reliant on VHS equipment with suspect (and very small) CRT displays.

Fortunately, this is technology of the past, and more up-to-date systems utilize hard-disk playback and flat-panel displays that make the viewing experience considerably more pleasurable.

Passenger vehicles such as buses and coaches also are being fitted with digital video broadcasting reception, using terrestrial or satellite signals, and equipment from providers such as KVH.

But surely the technology that underlies cellular networks is theoretically getting fast enough to deliver multimedia to vehicles. Or, is it?

In the past few years, weve seen mobile broadband offerings from providers such as AT&T, Verizon and Sprint gradually increase in speed. It wasnt so long ago that 300 kb/s was considered fast; now the mobile operators are talking about networks capable of 3.6 Mb/s and even 7.2 Mb/s download speeds. The truth is that the actual throughput measured to a laptop over these networks is on average less than 1Mb/s. That is hardly rocket speed, and a long way short of the technical specifications of HSPA (used by AT&T) and EV-DO Rev A (used by Sprint and Verizon).

So, its unlikely cellular networks could be used today for streaming live video and audio to passenger transport without aggregating multiple cellular connections from multiple providers to create a fatter pipe to the vehicle, and seamlessly switching between different networks as a vehicle moves in and out of coverage areas.

This method of intelligently combining different data networks is where products like Icomeras Moovbox cellular broadband gateway help bring high-speed communications to passenger vehicles where network performance is less than stellar.

Meanwhile, what does the future hold? Verizon announced in February it would accelerate its commitment to the next generation of cellular data networks known as LTE (long-term evolution) that promises actual speeds of up to 10Mb/s to the end-user. Initial roll-outs will commence as early as the first half of next year in key U.S. markets, with field tests underway in Minneapolis and Columbus, Ohio.

A joint venture between Sprint and Clearwire has seen live deployments of WiMAX in several cities.

In terms of streaming multiple live channels of video and audio over the internet to passenger transport, 2010 is shaping up to be the year where the rubber hits the road.

Jim Baker is chief marketing officer of Icomera.