17 September 2002 -- At last week's IBC2002 event in Amsterdam, The Netherlands, it was announced that Telewest Broadband - which provides multi-channel television, telephone and Internet services to more than 1.76 million UK households, and voice and datacoms services to over 73,000 business customers - has installed Harmonic Inc's METROLink DWDM transmission system in the upgrade of its network in south-west England. This is claimed to be the first deployment of 100GHz DWDM in the cable market.
With its ability to multiplex up to 32 wavelengths at 100GHz (0.8nm) spacing on a single fibre, the METROLink DWDM system enables Telewest to increase the capacity of its network and deliver narrowcast and multicast services to residential and business customers.
Harmonic says that the geographic area covered by Telewest's upgrade presented a unique set of challenges for implementing a balanced and scalable network architecture. First, the region is characterised by a mix of high- and low-density areas of population as well as short- and medium-distance links. Second, Telewest's existing network comprised several different architectures.
Harmonic's 100GHz DWDM transmission solution integrated into the Telewest environment using wavelengths that were below the window occupied by existing 1550nm trunk transmitters. This approach gives Telewest the narrowcast/broadcast infrastructure required to support a variety of bandwidth-intensive voice, data and video services.
"Adoption rates of our voice and data services have necessitated an upgrade of our existing network infrastructure so that we can deliver interactive services more efficiently to our geographically distributed customer base and add incremental capacity in step with growing demand," said Chris Eccles, Telewest's Network Architect HFC.
With DWDM, new capacity can be brought online incrementally to support new target services or to increase bandwidth for existing services. Harmonic says that, in the late 1990s, became the first company to provide DWDM transmission systems to the cable market, enabling broadband communications service providers to build balanced and scalable, pay-as-you-grow network architectures optimised to deliver a wide range of one- and two-way services.
"By upgrading to DWDM technology, Telewest has implemented a highly efficient architecture for cost-effectively delivering fast and reliable digital broadcast and narrowcast services," said Frank Patterson, Harmonic's Sales Director for UK, Middle East and Southern Africa. "Harmonic's open-standards-based approach allowed Telewest to rapidly deploy future-proof new technology that preserves its existing investments."