Conexant Systems Inc.  has formally thrown its hat into the pre-DOCSIS 3.0 game with the introduction of set-top silicon that can bond up to three DOCSIS downstream channels.
Conexant, which will compete in this particular segment primarily with Broadcom Corp. , said its new entrant - the CX24455X - will be targeted to set-tops that can support traditional broadcast video, as well as IP-based video services.
Conexant's new front-end modem chips for advanced two-way set-tops, including models with on-board digital video recorders, feature three demodulators with downstream channel bonding capabilities. Forthcoming, full-feature DOCSIS 3.0 modem and cable modem termination system (CMTS) technologies will enable operators to bond both upstream and downstream channels.
The new chipset can support a combination of two digital video streams, plus an additional channel to serve as a DOCSIS Set-top Gateway (DSG), a CableLabs-specified signaling platform that uses standard in-band DOCSIS connections, rather than proprietary out-of-band signaling, to deliver program guide information and other data to the set-top.
The same silicon system can also be used to bond up to three downstream channels. In 6 MHz cable systems (EuroDOCSIS plant uses 8 MHz channel spacing), those boxes would have the ability to provide speeds up to 120 Mbps - enough to handle a streaming HD video, the company said.
Conexant pointed to other features, such as IPv6 support, an integrated out-of-band cable physical layer (for legacy U.S. cable systems), and support for the SCTE 55-1 and 55-2 standards.
Conexant said the CX2445X is sampling today, with volume production slated for Q3 2007. The chipsets will be priced at $17 each "in production quantities."
The company has not announced any set-top partners for its new wideband-capable chipset. One possible candidate is Motorola Inc. , which already uses Conexant silicon in its all-digital DCT700 set-top.Conexant has also integrated its DOCSIS 3.0 silicon in Samsung  and Humax  set-tops for the Asia region.
Although Texas Instruments  will certainly provide heavy competition for DOCSIS 3.0 modem silicon, most of Conexant's pre-3.0 competition at the set-top level will come from Broadcom.
In January, Broadcom released the BCM7118 , an integrated chipset that can also bond up to three downstream DOCSIS channels, as well as offer multiple compression formats, including MPEG-2, MPEG-4 part 10 and VC-1.
That chipset is also the core of two reference designs: the BCM97118RNG (a low-cost, entry-level, all-digital box design), and the BCM97118 (integrated hard drive for multi-room DVR applications).