Belal Hamzeh, VP of Wireless Technologies at US-based R&D lab CableLabs, told Mobile World Live a new full-duplex technology unveiled this week is well suited to meet anticipated backhaul needs in a future, densified, 5G world.

CableLabs Full-Duplex DOCSIS 3.1 specification will enable symmetric multi-giagbit speeds over existing hybrid fibre-coaxial (HFC) infrastructure. While ostensibly designed to enable cable operators to boost broadband speeds for enterprise and other customers, Hamzeh said wireless operators were among CableLabs’ members pushing for the new technology.

“There’s a lot of excitement from both sides,” he said.

The new specification builds on CableLabs’ previous DOCSIS 3.1 specification to offer 10Gb/s both upstream and downstream. DOCSIS 3.1 originally offered 10Gb/s in the downlink, but only 1Gb/s up.

Small cells
“The expectation of the industry is that 5G, especially for the millimetre wave, will basically be a small cell deployment given the propagation characteristics of the millimetre wave spectrum. If you have small cells that means you have to have an infrastructure to every small cell to do the backhaul, and if you look at the pervasiveness of the HFC plants it makes it very well suited for backhaul solutions,” Hamzeh said.

Hamzeh added the full-duplex specification could eventually be converted for full wireless use, but noted the specification currently uses much larger bandwidths than are currently available to wireless operators. The spec calls for use of a channel up to 190MHz wide, where mobile operators today have much narrower channels of between 20MHz and 40MHz, he noted.

How it works
The new set up uses a combination of DOCSIS 3.1 technology alongside passive HFC network characteristics, self-interference cancellation technology and intelligent scheduling to allow upstream and downstream to flow concurrently on the same spectrum. The spec is backwards compatible with previous generations of DOCSIS technology, and can be implemented for individual customers on an as-needed basis.

CableLabs’ CEO Phil McKinney noted approximately 90 per cent of US households are connected to an HFC network, meaning the specification will enable cable operators to deliver higher broadband speeds to consumers without the need for expensive fibre trenching.

The updated full-duplex specification will be published to the CableLabs website later this month.