The U.S. Federal Communications Commission may regulate cellular signal boosters, which are designed to solve voice and data coverage gaps by picking up signals from carrier base stations and amplifying them in homes or vehicles.
On Thursday, the FCC started seeking comments on signal boosters and interference problems that they are accused of causing. As the first step in the process, which may result in a new set of regulations aimed specifically at these types of devices, the agency will hold a 45-day period for public comment. That will be followed by a 30-day period for replies to those comments.
Third-party vendors have been selling devices to boost U.S. cellular carriers' networks for several years.
One vendor, Wilson Electronics, has been pushing for regulation of the devices, saying that some products cause interference but Wilson has developed features to prevent it. CTIA: The Wireless Association, the main industry group for mobile operators, questions whether these methods are adequate. The group says there appear to have been cases of interference even from signal boosters that have the safety features.
Signal boosters typically have two radios: One receives and transmits signals with the cellular network, and the other acts like a small base station inside the building or vehicle where the user needs a stronger signal. Because they communicate with the carrier's network and a standard cellphone, signal boosters use the very frequencies that the service provider has licensed.
Using a carrier's own channels can cause interference, signal booster vendors and mobile operators agree. But they haven't agreed on ways to prevent that interference, and vendors continue selling the devices without specific rules. The FCC's request for comments "seeks to create appropriate incentives for carriers and manufacturers to collaboratively develop robust signal boosters that do no[t] harm wireless networks," the FCC wrote in its introduction to the document.
Boosters can help to fill in gaps in coverage that exist despite 99.6 percent of U.S. residents being covered by mobile voice service, the FCC said. Boosters can help consumers make emergency calls and keep public safety workers connected, but badly designed devices that interfere can prevent those same benefits, it said.
The FCC document lists several proposed requirements for signal boosters.
They should comply with power limits, automatically shut down if they cause harmful interference or go out of compliance with the FCC's technical rules, and in the case of boosters for vehicles, shut down when they get close enough to a cell tower that they are not needed. The paper also lists proposals to require clear information in labels and marketing about the legal use of the devices, and a requirement to coordinate frequency selection and power levels with the carriers operating nearby.
There are two major ways that a signal booster can harm a cellular network, according to Wilson, one of four entities that petitioned the FCC for new rules. If it is too close to any cell tower, it can interfere and degrade service, said Laine Matthews, director of business development. If the indoor and outdoor antennas of the booster are too close to each other, they can create oscillation, which can actually force nearby carrier base stations to shut down, Matthews said. This effect is similar to loud feedback caused by a microphone being too close to a speaker, he said.
Wilson claims its products come with mechanisms to detect and prevent both problems by powering down or turning themselves off. Some of its older gear lacks these, but Wilson immediately replaces them for free when they are reported, Matthews said. Wilson's position is that other boosters may not have these features, but all should be required to have them.
"Over time, we've learned more and more about what is required in a booster," Matthews said.
CTIA isn't so sure that improvements to boosters have solved the problem.
"We've seen it get worse and worse," said Brian Josef, assistant vice president for regulatory affairs. The group has heard reports from some of its carrier members that even boosters with some of the mitigation features have caused interference problems. It remains to be seen whether a set of regulations can be crafted that will prevent those problems, Josef said.
Both sides in the debate have some legitimate points, but it's important to get some solid figures from an independent source on the extent of the problem, said analyst Jack Gold of J. Gold Associates. He is concerned that the FCC's comments process will only draw out the parties' opposing views. Both sides have vested interests at stake, he said.
While the booster vendors want to sell more products, "Carriers don't want to admit that there's a coverage problem," Gold said. And where the problem really exists, carriers want to persuade customers to solve it with devices supplied by the carrier, such as femtocells.
Femtocells, which typically do a better job than signal boosters because they use wired broadband connections rather than a cell tower to connect back to the carrier, may go a long way toward giving subscribers stronger signals, Gold said.
In addition, it's important to keep the scale of the issue in perspective, Gold added. Signal boosters are not selling in the hundreds of millions, he said. "I think this fades away in a while," Gold said.