PALO ALTO, Calif. Copper Mountain Networks Inc. has provided intellectual property on packet fragmentation to seven different semiconductor companies as part of its new CopperSilicon program. The technology is provided on a royalty-free basis in exchange for commitments to develop client-side modem chips that can aggregate voice-over-digital subscriber line traffic in a way that's understandable to Copper Mountain's DSL access multiplexers.
Brecis Communications, Centillium Communications Inc., Conexant Systems Inc., GlobeSpan Inc., Ishoni Networks Inc., Metalink Ltd., and Virata Corp. are the first seven players to join the CopperSilicon program, and they currently represent a significant percentage of the total DSL silicon market. But Copper Mountain hopes to ink pacts with virtually all DSL semiconductor players, said Pavan Vohra, director of business development, though it was interested in talking to symmetric DSL specialists first.
Copper Mountain's DSLAMs were originally based on SDSL and have only recently expanded to include G.Lite (splitterless ADSL) support. DSLAMs developed for ADSL and which followed the Joint Procurement Committee model used Asynchronous Transfer Mode as an interface, while Copper Mountain's DSLAMs utilize a native Internet Protocol interface.
This created a dilemma as Copper Mountain's customers among the competitive local exchange carriers (CLECs) began moving to packet voice services, Vohra said. To deal with packet traffic in an IP environment, Copper Mountain developed pre-emptive quality-of-service algorithms and an "adaptive fragmentation" approach, which breaks up large data packets for delayed delivery whenever packet voice traffic is on the line.
While this solution works fine for a central office, Vohra said, CLECs wanted assurances that the integrated access devices on the client end could talk to Copper Mountain DSLAMs as the IADs were upgraded to voice service. Th is spurred the CopperSilicon campaign.
While the implementation of "adaptive fragmentation" depends on the silicon vendor, in most cases the support circuitry is not complex and can be integrated into existing xDSL chip sets, according to Vohra.
Vohra was asked what would compel a silicon vendor to add vendor-specific DSLAM logic to a client chip set. In response, he pointed to a recent study by Dell'Oro Group that showed Copper Mountain with the top market share in SDSL, IDSL and the SDSL/IDSL combination, in terms of both revenue and ports shipped. The impetus for interworking with a market leader should spur design efforts to add "adaptive fragmentation" to chip sets, Vohra said.