Last Mile Goes Wireless

There are 8 million small businesses in the U.S. that spend $100 billion on voice and data services. Yet operators can’t reach nearly half of that group economically, even though they’re close to cable plant.

What’s worse, with Wall Street pressure to curb capital expenditures, traditional plant extensions have been frowned upon.

Enter last-mile wireless technology, which provides a cheap alternative for the business divisions of MSOs looking to make further inroads in the commercial space.

Arcwave Inc., which already supplies wireless gear to four of the top five MSOs, has introduced the Data Over Cable Service Interface Specification 2.0 version of its ARCXtend product, which consists of a network hub device and corresponding antennas deployed at business sites to provide high-speed cable-modem service.

The catch: the last mile is wireless.

“If you have a well-designed plant, you shouldn’t have any problems with wireless,” said Arcwave vice president of marketing Chris Martin.

Charter Communications Inc.’s Medford, Ore., system has already deployed last-mile extensions to three businesses and is currently engaged in site survey work on eight others.

“It’s a great model because it is so affordable,” said Charter network-sales engineer Keith Grunberg.

Grunberg said there are a number of businesses and office parks that are between one-quarter mile and two miles from Charter’s wireline plant. Even aerial extensions would be cost-prohibitive, he said, so underground construction was out of the question.

Wireless became the answer.

Martin said Arcwave installs a network hub “which can connect at any location in the cable plant using power-passing taps. It takes an F-connector input,” Martin said. “The gear interfaces with the [radio-frequency] portion of the plant. No demodulation is necessary.”

The operator then places a small antenna at the business customer location.

“It needs line-of-sight capability,” Martin noted.

The antenna is then connected to the cable node within the business by coaxial cable plant. The entire setup can be monitored by standard cable equipment, he said.

The new DOCSIS 2.0 software will allow MSOs to offer more upstream bandwidth for services such as voice-over-Internet protocol telephony.

“We can support more people with 2.0 because we won’t become upstream bandwidth-limited,” Martin said. “You also get improved noise cancellation.”

Grunberg said the wireless technology allows Charter to compete with Qwest Communications International Inc. and others for small business accounts. And DOCSIS 2.0 will allow Charter to expand its feature set.

“We’re looking to do a rollout of VoIP solutions in the next six months,” he said. “Once we get the DOCSIS product lined up and tested, we’ll also roll out some IP cameras for surveillance.”

There are a few things engineers need to watch out for with wireless extensions, Grunberg said. “When you come off a node within a system, you want to know what bandwidth utilization you already have,” he said. “You don’t want more than 80% utilization off that node.”

Charter is currently provisioning 3 Megabits per second downstream and 1Mbps upstream, and has plans to add a 5 Mbps/1 Mbps service soon.

“With implementation, you don’t just go and slap radio [antennas] up,” Grunberg said. “You need to look at different channels within the spectrum to make sure you have a clean area to work from. You can get different interference in different areas of town. And you have to consider some multipath issues, like a metal roof, metal sliding. You don’t want to get multipath interference coming back on you.”

Arcwave was formed several years ago, and merged with Advantage radio cells — which had created some DOCSIS wireless applications — in April of 2003. “We took the product they were selling to wireless ISPs, reworked the story and pitched it to the cable companies,” said Martin.