Following an initial product that brings a “dual-band” architecture to DOCSIS 3.1-based modems, Peregrine Semiconductor has introduced a new RF switch that will help operators future-proof as they consider new spectrum splits that could widen (and speed up) an MSO’s upstream data path.

Its new UltraCMOS PE42723 RF Switch, an upgrade of the PE42722, is designed to boost performance in a smaller footprint (12-lead 3x3 mm QFN package)

And, like its predecessor, the new switch ($1.56 each in order quantities of 10,000) will support a range of spectrum splits.

In North America, most MSOs use a “sub-split” upstream that lives in the 5MHz-42 MHz range, but some are also looking at a “mid-split” that would raise the ceiling to 85 MHz, or a “high-split” that would push it up to 204 MHz.

“The mid-split will be the new sub-split,” Kinana Hussain, director of marketing at Peregrine, predicted.

“The ability to support dual upstream/downstream bands in the same CPE device is a critical enabler to making DOCSIS 3.1 a reality,” Jim Koutras, director of product management at DOCSIS tuner/silicon maker MaxLinear, said in a statement.

Peregrine’s earlier-generation technology has already begun to gain some market acceptance in the newest wave of D3.1 modems. Products from three of the first five DOCSIS 3.1 modem vendors that recently achieved certification at CableLabs – Netgear, Ubee Interactive and Technicolor – use Peregrine’s switchable-band selector technology in their respective products. Those modems are hybrids in that they are capable of supporting both DOCSIS 3.0- and DOCSIS 3.1-based data signals. 

Peregrine’s approach is also emerging as CableLabs continues work on a “Full Duplex” approach that could eliminate the need to do spectrum splits and put MSOs on the path toward more symmetrical DOCSIS offering.  

DOCSIS-based services are considerably asymmetrical.  For example, Comcast, the first MSO to deploy D3.1, is starting off with a trial offering that pairs a downstream that maxes out at 1 Gbps with an upstream that delivers up to 35 Mbps.

CableLabs is currently in the feasibility phase with Full Duplex, but says it’s on a “fast track” to become an extension to the current D3.1 specs. But it will involve some hardware additions, and there’s still no telling when Full Duplex will become a deployable reality for the cable industry.

In Hussain’s view, Full Duplex could become a commercial option for the cable industry in four to five years.

Speaking at a Light Reading event in Denver last week, Jorge Salinger, Comcast’s vice president of access architecture, said the potential presented by the Full Duplex concept should not change operator plans to do spectrum splits that provide more upstream spectrum.