Earlier DOCSIS cable networks can only support transmissions within a single downstream 6 MHz radio frequency (RF) channel, limiting maximum throughput to around 40Mbps (shared). DOCSIS 3.0 upgrades will allow tuning into multiple 6 MHz channels through channel bonding technology, offering shared downstream data rates of 160 Mbps or higher and upstream data rates of 120 Mbps. Downstream speeds could theoretically reach as high as 320Mbps -- thanks to new eight channel bonding chipsets.

Channel bonding combines multiple quadrature amplitude modulation (QAM) channels to ultimately offer cable broadband customers faster speeds. While DOCSIS 3.0 may not be here yet, ARRIS, Motorola, and Cisco are releasing pre-cert hardware that takes advantage of these advancements. We've been seeing a growing number of pre-cert 50-100Mbps cable solutions popping up in markets such as the UK, South Korea, and Singapore.

Comcast is the only cable operator in the U.S. to deploy pre-certification DOCSIS 3.0 technology at speeds of 50Mbps, but so far that's only in one market. Videotron was the first carrier in north America to offer pre-cert speeds, delivering both 30Mbps ($64.95) and 50Mbps ($79.95) tiers with 30Gb and 50GB caps, respectively.

This week Europe got in on the pre-cert action, a company by the name of Liberty Global saying they're offering 120Mbps DOCSIS 3.0 speeds in Amsterdam. "The launch of our Fiber Power broadband services in Europe marks another milestone in cable's long-standing superiority of DSL," insists Liberty Global CEO Mike Fries. Liberty says they'll launch the product in Switzerland and Austria before the end of this year, and the rest of their European markets by the end of 2009.

You'll notice that none of these announcements go out of their way to mention upstream speeds, largely because upstream channel bonding is still being worked on. The result is some rather top heavy tiers being offered in many of these markets (such as 100Mbps/2Mbps). Back to the States, Comcast has promised to have DOCSIS 3.0 technology deployed to 20% of their footprint by the end of this year, and their entire customer base by the end of 2010.