Centillium advancing ADSL 2++

Centillium Communications is bringing the ADSL 2++ technology already working in Japan to the rest of the world, hoping to stimulate the market for chipsets that make the most of ADSL's reach.

The company is introducing its Pharos ADSL central office (CO) physical layer (PHY) chipset for the Annex A (North America, China and Korea) and Annex B (Europe) markets, to be available April 1. The Pharos enables service providers to deliver ADSL and ADSL 2, but also enables services at speeds of 50 Megabits per second downstream and up to 5.5 Mbps upstream using ADSL 2++ and is an alternative to deployment of VDSL technology for delivering triple-play services over a copper network, said Ken Madison, senior product marketing manager for Centillium.

The technology is already being used in Japan by NTT and its vendors, NEC and Sumitomo Electronics, he added. It is also being considered by the Japanese standards body, TTC.

"ADSL 2++ preserves the cost basis at the ADSL level for the service provider," Madison said. "It is much lower than VDSL, which is at least two to three times more expensive than ADSL."

Centillium is also contributing directly to the ITU-T global standards body in hopes of advancing the ADSL 2++ cause, he added, but as a single vendor, is facing some resistance.

"It is a slow process," said Madison.

In North America, Centillium is working with both UTStarcom and Lucent Technologies. The company is already in talks with three carriers on this continent, discussing the options with both them and their equipment vendors.

Pharos is spectrally compatible with VDSL, so that a smooth transition is possible as the technologies evolve, said Madison.

The Pharos ADSL CO PHY consists of a single monolithic 12-port digital processor and a two-port analog front-end with integrated line drivers that are optimized for Annexes A, B and C. For Annexes A and B deployment, Pharos uses a common line-card design that can be altered using different firmware.