Towerstream moves to WiMAX

Metro WISP completes trial using Alvarion gear, plans initial major market rollout using 3.65 GHz band

Towerstream is officially embracing WiMAX, shifting its technology in the nation’s largest markets away from propriety broadband wireless gear to the new 4G standard going forward. Towerstream said today it has completed WiMAX trials in an unnamed metro market using Alvarion gear and plans to use that technology going forward in all new deployments.

Though Towerstream has billed itself as a WiMAX operator for the last year, its rollouts in New York, Los Angeles, Boston, San Francisco, Chicago, Miami and Dallas have all used pre-WiMAX equipment from Aperto Networks and Alvarion in the 5.8 GHz unlicensed frequencies. The new WiMAX gear, however, uses the new 3.65 GHz designated by the FCC for unlicensed but restricted use. All operators must register their equipment in the markets they deploy in, and though competitors may use the same spectrum, they must to do it in coordination with one another, creating an unlicensed band with some protections to its users.

Though Towerstream won’t reveal what market it conducted its trial in for competitive reasons--Towerstream will use the same market for its commercial launch--CEO Jeff Thompson said he was highly pleased with the results. “We’ll be in beta for a couple of months,” he said. “Then we’ll go fully commercial.”

Though Towerstream won’t retire any of its current equipment, Thompson said the ISP will use WiMAX gear from now on for its T-1 replacement services, offering sub-10 Mb/s links to smaller and medium-sized businesses. For larger companies though, Towerstream will continue to use dedicated point-to-point links supplied by DragonWave and Ceragon Networks.

Though Towerstream is using the mobile version of WiMAX it, like many ISPs, is using it for fixed wireless purposes. Thompson said Towerstream trialed Redline fixed WiMAX gear in Boston, but wasn’t satisfied with its performance. Due to the huge economies of scale behind Mobile WiMAX and its additional capacity, the IEEE 802.16e standard was the obvious choice for Towerstream’s technology roadmap, Thompson said. As its name implies, Mobile WiMAX supports mobility, but it’s unlikely Towerstream will offer a mobile service.

“We’re not going to become a cellphone replacement company offering service to people going 70 mph down the highway,” Thompson said. “We could become a hotspot company, where people connect with laptops, but that would be more nomadic, not mobile.”

Even if Towerstream wanted to use WiMAX for mobility, it would run into difficulty at the frequency band it operates in. Not only is the higher frequency not optimal for mobile deployments, adding mobility could cause interference issues. Unlike licensed spectrum, 3.65 GHz would be shared by multiple providers. While managing point-to-multipoint links without interfering with neighbors is feasible, crisscrossing mobile signals would not, said Ashish Sharma, vice president of corporate development for Alvarion.

As a fixed wireless technology Mobile WiMAX at 3.65 GHz holds tremendous promise though, Sharma said. Several vendors aside from Alvarion have optimized their licensed 3.5 GHz WiMAX kits for the U.S. band with little additional development costs. And Sharma said Alvarion is conducting multiple trials with other operators in the spectrum. Despite the interest in 3.65 GHz, it’s unlikely that equipment at that band will ever be certified by the WiMAX Forum, receiving the official WiMAX stamp. The configuration is unique to the U.S. and since it doesn’t support mobility, there won’t be a wide range of devices that would necessitate standards-based interoperability testing.