Capital Radio picks ATM over IP

Capital Radio has delivered Europe's first audio-over-ATM network. It will gain a 100-fold bandwidth increase, which will...

Capital Radio has delivered Europe's first audio-over-ATM network. It will gain a 100-fold bandwidth increase, which will underpin business expansion into 3G and digital television.

Asynchronous transfer mode, which has traditionally been a high-capacity internet backbone technology, has provided the company with a 155mbps cloud where its London offices used to use 256kbps connections out to regional offices.

This will replace transmission methods for audio, which included ISDN, CD and satellite for audio and data traffic, and will help Capital to reduce the number of servers.

The network will consist of audio-over-ATM to 12 sites in the UK, a 10mbps internet connection scalable to 622mbps to Thus' core network, and a web streaming platform that allows for several thousand concurrent streams as well as a 100Gbyte storage area network.

A spokesman for Capital Radio said the new network will allow the company to take advantage of more relaxed regulations which will apply under the Broadcasting Act, which comes into force later this year, to expand the number of stations it can own and exchange content between them.

Longer-term benefits will centre on the ability to develop the use of content across different media, such as digital radio, 3G phones and digital television, as they become available.

The spokesman said a decision was taken not to use Internet Protocol as a transmission method. "We could have used IP but decided it was not ready for the demands of quality audio transmission," he said.

Why ATM is a network winner   

Asynchronous Transfer Mode is a network technology for local and wide area networks developed in the early 1990s. The topology uses small packets of data, which are routed using switches that establish logical circuits from end to end, to guarantee quality of service. Unlike telephone switches that dedicate circuits end to end, unused bandwidth in ATM's logical circuits can be appropriated when needed so that, for example, unused bandwidth in a videoconference circuit can be used for data. ATM is widely used as a backbone technology in carrier networks and large enterprises. It is highly scalable and supports transmission speeds from 1.5mbps to 9953mbps.

Read more on IT legislation and regulation