Don't hold your breath for online TV

Sports fans can substitute the latest event of your choice, complete with player profiles, historical data and records, etc. Current-events freaks and political animals substitute the news bulletin, debate or party conference of your calling. It would be great if everyone in the household could have their own such device, so that dad can watch the footy, mum a girl movie and junior can find out how to make an A-bomb in between on-line classes.

Unfortunately, the best current version of this for most of us, even using the broadest-band connections, is a small, poor-resolution screen that appears surrounded by logos on a device that takes an eternity to start up – if you can get satisfactory access to the Web regularly.

So, what is the problem with on-line TV and when can we expect our services to improve?

Notwithstanding the argument that people don’t want to use their TVs for surfing the Web, the answer is one of simple maths: the best Internet delivery services available are simply nowhere near fast enough to cope with the services described above.

A cable-TV line and modem can cope with a maximum of about 2M/second, which has to be split between the number of users attached to any cable. So if you have three devices in the house and all want to use them all once, you get 666K/second each. DSL lines can handle about 1.5M/sec (9M/sec if you include the asynchronous download only).

That sounds pretty damn fast until you consider that a single stream of TV-quality digital video footage requires a transmission of about 50M/sec – more than five times faster than the fastest option available. Delivery of these services over a wire network is simply not feasible.

Of course, there is always Gilder’s Law, which states that available bandwidth will treble every 18 months. At that rate, if we assume that a current broadband user can expect a 1M connection, then in 6 years (4 x 18 months), that same user should be able to use the Internet to access a single broadcast-quality video signal with enough spare bandwidth to request accompanying text information or other views. It will be a lot longer before everyone on their block can access the same quality of the signal of their choice.

In the meantime, the ‘net will remain the province of text-based sites, and Murdoch and Co will seek their fortunes via satellite-borne Interactive-TV loops with PVR devices. Unsatisfactory as these loops are, I, like other content creators, publishers and consumers, just have to wait patiently for the day when "I Love Lucy" will replace tiny, jerky videos that never play.