FiberTower Makes Case for Small Antennas for 11 GHz Band]

Tarun Gupta, chief architect at FiberTower, said most commenters in an FCC docket were generally supportive of his company’s proposal. The technology utilizes 2-foot antennas, which weigh 35 lbs., vs. 125 lbs. for the larger antennas, and costs 1/3 as much. Gupta said wireless carriers in particular may find the proposal attractive as they make greater use of the 11-GHz band. The band offers much wider channels for advanced wireless services than the 10-GHz band, which has carried most of their backhaul traffic.

The proposal has implications for a range of companies. Electric utilities use 11 GHz for communications among employees and with their generation facilities. Gas pipelines use the frequency to monitor and control compression in their lines. Public safety agencies also use the frequency. “Conceptually, as well in reality, it’s easier to deploy,” Gupta told us. “There’s the pure cost of the dish itself. There’s the aesthetic perspective of using a smaller antenna. There’s the weight perspective. There’s the zoning impact. There’s leasing impact and there are structural impacts.”

The drawback of a smaller antenna remains its less tightly focused beam, FiberTower acknowledged in a July filing. To protect other users of the spectrum, the company proposed a rule change providing that the owners of small antennas are responsible for any problems they cause. Gupta said problems seem unlikely: “Even if you're using a 2-foot antenna and a wider beamwidth you have less gain. Even though you're sending energy in an adverse direction you're sending less energy.”

Proposed protections would do nothing to protect fixed satellite service (FSS) operators from the increased interference the industry expects, SIA said. The proposal would also “interfere with FSS spectrum rights,” it said. FiberTower said in its proposals that the antennas are more likely to cause interference to satellite earth stations, and proposed that the small antenna operator be responsible for coordination with earth station operators. Specifically, FiberTower said the smaller antennas couldn’t cause more interference than a larger antenna and coordination would be required each time a new satellite earth station entered the band.

But SIA said the company’s rule-specific proposals don’t mention satellite earth station operators and would only give FS licensees the right to request changes to small antenna operations: “Even assuming that the omission of earth stations from the FiberTower proposed rules was an oversight, the language of the rule is vague with respect to how a new application would exercise its rights.” SIA said more details -- like the timing of the request and the change and consequences for failure to comply -- are missing from the proposal. FiberTower’s proposal also failed to address the effect of placing more FS antennas near earth stations, pointing error, and how that harmful interference would be addressed, SIA said. SIA said FiberTower also fails to convince that FS operators need more flexibility.

FiberTower will work with the satellite companies to address their concerns, Gupta said. Other commenters supported the proposal. “The rules proposed by FiberTower will deliver the benefits of small antennas -- lower cost, greater flexibility of installation, and more efficient use of the band -- with no detriment to other users,” said the Fixed Wireless Communications Coalition. - Howard Buskirk, Jeanene Timberlake