It happened with little fanfare, but last month some technical trials held in Dublin removed a major obstacle to delivering high-quality TV and video content over the internet in Ireland.
In December INEX, the hub for Irish internet service providers (ISPs), conducted a test between two of its members, the education and research network HEAnet sent a streaming video of a live Dáil debate to Magnet Networks. Magnet sent a live stream of RTÉ 1 television and a high-definition TV channel from its network to HEAnet. At one point in the trial the high-definition stream reached up to 20Mbps.
TV over the internet is not new — RTÉ has streamed budget speeches and even the Rose of Tralee via the internet before — but the cost of having enough bandwidth to cope with demand meant that the size and quality of the images tended to be greatly reduced. Few people would have rushed to switch off their TVs at the prospect.
These services would have used a technology called unicast — basically, for every request that’s made for a video clip, a new version of it is sent to the user. This carries a huge cost and is why December’s test of a technology known as multicasting is so significant.
The technology cuts the cost of delivering video content over the internet, as Nick Hilliard, head of operations at INEX, points out. “It’s an ideal means for transferring streaming data from a single source to a lot of destinations,” he says. “It will massively reduce the bandwidth that the streaming provider needs and because the bandwidth is reduced they can send out much higher quality images.” It would also allow content producers to offer streams suitable for different audiences depending on their connection speeds, Hilliard suggests.
Multicasting delivers packets of data in a way that avoids delay, adds Hilliard; in simple terms, it means the picture won’t jump or freeze in mid-broadcast.
Marcus O’Doherty, technology development manager with RTÉ’s Publishing Division, says that multicasting is a “significant step forward”, as it makes the internet a viable platform for its TV and radio services, in the same way that terrestrial, cable and satellite networks are today. This wouldn’t have been possible before. “For us, multicasting technology represents a very attractive option for streaming live content,” he says. “We’re extremely keen for this technology to take hold.” Just as with a standard TV broadcast, multicast means that the cost to RTÉ is no greater whether there is one or 100,000 viewers.
The technology also neatly sidesteps the problem every TV station has — there are only so many hours in the day to give to every individual programme. Now, the internet could be an alternative delivery medium that could stretch the length of a broadcast beyond what the traditional schedule allows. To take the example of boxing, there might only be enough airtime to show the main bout on TV but fight fans could watch other matches on the undercard via multicast on the web.
Uses needn’t be restricted to TV content only — multicasting also makes possible distance learning, online collaboration applications or even computer gaming.
But if good things come to those who wait, Irish internet users may find themselves hanging on for a little longer. Multicast doesn’t work with standard ADSL, which is the most common broadband technology currently used in Ireland. In order to receive a multicast signal, the user’s ISP must have a network based on ADSL 2+. According to Hilliard, newer players such as Magnet Networks and Smart Telecom are already building their networks on this technology. Where they go, the more established ISPs are sure to follow and before long, true TV over the internet will be a viable prospect.
By Gordon Smith
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