Broadcom has unveiled a cable gateway chipset that bakes in new DOCSIS 3.0 silicon that is capable of bonding 32 downstream channels and eight upstream channels – offering enough punch to produce maximum downstream speeds above 1 Gbps.
In EuroDOCSIS networks with 8MHz-wide channel spacing, the chip can hit max downstream speeds of 1.6 Gbps, and about 1.2 Gbps in North American DOCSIS networks that use 6MHz-wide channels. The DOCSIS 3.0 chip utilizes Broadcom’s Full Band Capture technology, which lets operators capture channels for bonding from anywhere one the spectrum (up to 1GHz), rather than obtaining them from more limited, 100MHz-wide blocks.
Broadcom’s new hybrid IP/QAM gateway system-on-chip, called the BCM7145, essentially leapfrogs Intel’s Puma 6 DOCSIS 3.0 chip, which can bond up to 24 downstream channels and 8 upstream channels. Hitron Technologies and Netgear have already obtained CableLabs certifications on DOCSIS 3.0 gateways powered by the Puma 6 and MaxLinear receivers. Broadcom’s latest SoC is for "headed" gateways with video outputs, and would generally be installed near the home's primary TV set.
Broadcom's latest gateway chipset also features a video decoder based on H.265/HEVC, a codec that’s about 50% more efficient than H.264/MPEG-4 and is roughly on par with the bandwidth required to deliver 1080p video in the MPEG-2 format. It’s expected that service providers will lean on HEVC to keep bandwidth demand in check as they start to introduce Ultra HD/4K video services.
The chipset also supports the 2.0 version of the Multimedia over Cable Alliance (MoCA) platform, which can support speeds up to 800 Mbps on the home’s coax network, as well as 802.11ac, a new version of Wi-Fi that is targeting wireless speeds of greater than 1 Gbps.
Those advanced home networking platforms will come in handy as consumers stream increasing amounts of HD video to tablets, PCs, set-tops, gaming consoles and smartphones hanging off the home network. Broadcom’s new SoC also supports a quad transcoder that’s capable of turning QAM video into IP streams that can be shuttled along to four wireless mobile devices simultaneously. With the native IP capabilities factored in, Broadcom claims its new gateway SoC can stream content simultaneously to more than 10 video clients. .
"Broadcom's new BCM7145 is a giant step forward in set-top box gateway chip design and is a key enabler for an all-IP cable platform," said John Gleiter, VP of set-top box marketing for Broadcom's Broadband Communications Group, in a statement.
Broadcom said the Nexus-Trellis set-top box software on the BCM7145 supports several platforms, including the Comcast-led Reference Design Kit, a pre-integrated software bundle for IP-only and hybrid QAM/IP gateway and video client devices. Comcast’s next-gen X1 video platform is the first product based on the RDK.
The BCM7145 is currently sampling to customers and is slated for volume production by 2014, said Broadcom, which announced the SoC at this week’s Anga Com show in Germany.
