Better wireless rules needed, says BellSouth CTO

Engineers need to engage with regulators to sort out looming problems in network technologies, including broadband-over-powerline and Wi-Fi, according to BellSouth's CTO.

In a keynote address last week at the IEEE Globecom conference, Bill Smith also said BellSouth believes digital subscriber lines remain strong as an access network and WiMAX is a strong contender for last-mile access where DSL lines don't reach.

Regulators should carve out separate frequencies for powerline access and home networks. Otherwise, Smith said, the two will cause significant interference and consumer backlash.

"There are issues here the IEEE needs to get involved in. We can't leave consumers to deal with these challenges," Smith said.

Similarly, it "makes no sense at all" that Wi-Fi enabled cellphones come under one regulatory regime inside buildings and another regulatory regime when they connect to cellular nets outdoors. BellSouth is conducting a trial at one of its corporate offices using such dual-mode cellphones enabled with Wi-Fi.

Separately, BellSouth is using ADSL2+ as an access technology for its IPTV trials now installed in about 100 employee homes. The trial has been delayed due to a new version of the Microsoft IPTV software just now being rolled out along with delays for delivery of unnamed components from the company's residential gateway provider.

Smith predicted that within about 12 months new DSL chipsets will emerge supporting both the ADSL2+ networks BellSouth currently deploys and the VDSL nets the telco hopes to use in the future. "These agile chipsets will sit in the DSL Access Multiplexers and serve whatever traffic comes down the line," said Smith.

BellSouth now gets at least 23Mbps from all its DSL lines and more than 25Mbps in best-case scenarios. "I wish I had fiber to everybody, but we believe the performance of our DSL systems put us in the game," said Smith referring to competition from cable TV providers and telcos such as Verizon who are installing fiber systems for IPTV.

Advances in MIMO technology and other work will help extend DSL even beyond the 80Mbps range of a single VDSL line. "We haven't seen the last of DSL improvements by any means," said Smith.

BellSouth is investigating WiMAX as a strong contender for the 15 percent of its coverage area that cannot be reached by DSL lines. "We have a fair amount of spectrum [for WiMAX], and we have used [WiMAX] in a couple cases so far," Smith said.

- Rick Merritt
EE Times