Docsis 3.0, sometimes branded by MSOs as "wideband," is a CableLabs
specification that uses channel bonding techniques to create one larger (and faster) logical pipe, producing shared speeds in excess of 100 Mbit/s.
The specs call for equipment to bond at least four channels in the upstream and downstream directions, although some recently announced modem chipsets can bond up to eight downstream channels, creating a fat pipe capable of pumping out bursts in the neighboarhood of 320 Mbit/s.
The early wave of wideband deployments have been limited to downstream channel bonding. Services that use upstream channel bonding could emerge by late 2009 or sometime in 2010.
Channels for North American Docsis are 6 MHz wide; EuroDocsis channels are 8 MHz wide.
In addition to creating more capacity through channel bonding, Docsis 3.0 bakes in other features such as IPv6 addressing, IP multicasting, and the Advanced Encryption System (AES), an element that some government and business customers are now insisting upon.
In addition to publishing the specs, CableLabs also conducts interoperability testing on Docsis equipment, awarding "qualification" to cable modem termination systems (CMTSs) and "certification" to cable modems. In addition to ensuring interoperability, Docsis certification also gives vendors the green light to offer the equipment through retail channels.
For more on Docsis 3.0, please see:
- Docsis 3.0 Specs Head to the Freezer
- Comcast Wraps Up '08 Wideband Rollout
- Shaw Breaks 100-Meg Barrier
- Bay Area Gets Wideband
- Broadcom: Sub-$50 Docsis 3.0 Modem in Sight
- TI Flexes Docsis 3.0 Muscle