Historically, times of technology transition result in “hybrid” approaches. Thus, one sees hybrid computing environments partly using cloud and also premises-based data centers.

The cable TV industry developed hybrid fiber coax to strengthen its networks by grafting optical fiber backbones onto distribution networks and then gradually extending fiber deeper towards end user locations, while retaining existing copper drop cables and a substantial amount of distribution network copper.

Telcos use variations of media, ranging from all-copper access media to all-fiber media to hybrids that extend fiber to neighborhoods.

That hybrid approach extends the life of the older technology while the replacement is introduced.

So it is that BT (News - Alert) reports G.fast trial results suggesting that “1 G.fast” technology could deliver 700 Mbps speed downstream and 200 Mbps upstream, if G.fast was deployed, to about 80 percent of locations now served by fiber to the curb networks (FTTC).

That trial is part of development efforts seeking to reach gigabit speeds over hybrid networks using copper drops and optical fiber distribution. The trade off is distance for speed: the longer the copper span, the lower the potential bandwidth delivered to a customer location.

In its recent G.fast tests, BT has been able to deliver download and upload speeds of 786 Mbps downstream and 231 Mbps upstream over an FTTC line using a 19-meter (about 62 feet) copper drop cable.

That is significant since many fixed networks in suburban or urban areas feature copper drop cables of perhaps 100 feet to 150 feet long. To achieve 700 Mbps, a service provider would have to use a “fiber to the telephone pole” or “fiber to a cabinet” network that places cabinets about as densely as a telephone pole network does.

BT also tested G.fast with a 66-meter (216 feet) copper line and found that the download speed fell to 696 Mbps while top uploads weighed in at 200 Mbps.

In other words, “close to gigabit speeds” might be possible over relatively standard drop cable networks.

The International Telecommunication Union is working on standards for G.Fast, so commercial deployment will have to wait a bit. Some think the standard could be finished by 2015.

The development shows how much value a hybrid approach can yield during a time of technology transition. Decades ago, few believed such performance was possible, using such pair-gain technologies.