Data Centre


CableLabs signs off MAC spec for DOCSIS full duplex

Fibre, schmibre: existing cable TV networks edge closer to symmetric 10 Gbps capabilities

By Richard Chirgwin


US standards outfit CableLabs has added another piece to the Full Duplex DOCSIS 3.1 jigsaw, with the release of the key MAC layer specification for the standard.

DOCSIS 3.1 Full Duplex is designed to push symmetric 10 Gbps over the world's cable (or hybrid fibre-coax, HFC) networks.

The spec expands the existing DOCSIS media access control layer with messages specific to setting up full duplex communications between the cable modem and the upstream cable modem termination system (CMTS).

As CableLabs architect Karthik Sundaresan explained here, the MAC layer changes let a cable modem acquire and initialise a full duplex channel, as well as supporting new processes including sounding, echo cancellation training, and resource block assignment.

Sounding refers to how the system identifies groups of modems that will interfere with each other if they receive and transmit at the same time in any sub-band of the system. Echo cancellation is a common mechanism to prevent interference between upstream and downstream communications.

Resource block assignment refers to how the CMTS assigns frequency bands to cable modems for full-duplex communication.

With the MAC layer work complete for now, CableLabs expects silicon design to accelerate, and starting this month the organisation is running interoperability events.

Sundaresan added that the work-in-progress includes incorporating OSS support in the full duplex spec, further development in the physical layer, and refinements to PHY and MAC specs once vendors start hooking products together. ®

Sign up to our NewsletterGet IT in your inbox daily


More from The Register

CableLabs, Cisco working on LTE-over-DOCSIS

+COMMENT Plan avoids the need for new fibre to connect a squillion small cells

CableLabs' many hands make light work – at four terabits per second

New optical standards give cable operators lots of headroom as they fibre up

CableLabs backhaul spec gets speed boost

Faster fibre will help networks cope with the Netflix effect

nbn™ joins standards body CableLabs

Yet more evidence that nbn™ just won't change its mind and build fibre-to-the-premises

Arris slaps down US$800m to buy Brocade's wireless bits

Broadcom waves farewell to what used to be Ruckus and the ICX switch business

Intel's buggy Puma 6 chipset earns Arris a gigabit-modem lawsuit

Laggy silicon at heart of broadband boxes lands gateway maker in court

Alert: AT&T customers with Arris modems at risk of remote hacking, claim infosec bods

Just the usual procession of firmware vulnerabilities

Australia defies trend for network sales slide, shovels cash at Cisco

Good old-fashioned hardware-defined networking growing like topsy Down Under

Spooked Cisco chief phoned AWS, asked: You're not making a switch, are you?

Switchzilla's share price dipped following rumor of direct rivalry

Cisco snags potential customer-sniffing biz for an undisclosed sum

OEM partner July Systems' tech tracks in-store punters by Wi-Fi