Picocells: Like femtocells, picocells function like small cellular base stations and use an IP connection for “backhaul.” Also like femtocells, they operate with very low output power.

But picocells have a bit more range: They can cover buildings up to 30,000 square feet, according to an article from Stefan Scheinert of LGC Wireless. Some airports have used picocells.

The biggest distinction: “Picocells are normally installed and maintained directly by the network operator, who would pay for site rental, power and fixed network connections back their switching center,” according to ThinkFemtocell.com, a leading authority on the technology. “Femtocells differ from picocells because they are intended to be much more autonomous. They are self-installed by the end user in the home or offi ce, primarily for the user’s benefit.

“Femtocells automatically determine at which frequency and power levels to operate, rather than being directed from a centrally determined master plan. This allows the network to adapt automatically as new femtocells are added or moved without the need for a complete frequency replan.”

Ip.access, based in the United Kingdom, is one of the main picocell players.

Like femtocells, picocells have the potential to interfere with the larger, outdoor network and with other picocells. But they also can partner well with the following technology: Distributed Antenna Systems.

DAS: Distributed Antenna Systems are bigger solutions for bigger spatial areas, such as college campuses, large hospitals and casinos. A DAS connects to one or several wireless services and rebroadcasts the signals. An onsite cellular carrier base station or repeater is put in place, and the signal is ”boosted” to improve reception. Multiple remote antennas are placed throughout the site, allowing the signal to be extended.

The University of Notre Dame set up a carrier-neutral distributed antenna system throughout the campus using 16 small “stealth” antenna sites.

San Jose, Calif.-based NextG Networks, Inc. is one of the leaders in the distributed antenna system (DAS) world. It uses fiber-optic architecture and low-impact, low-emission equipment. Other leaders include ADC, Andrew, Cellvine, InnerWireless, Powerwave, and Spotwave Wireless, plus integrators such as LComm Global Solutions, InSite Wireless Group, and Nsoro, according to Wendy Chretien, a senior network systems consultant with Elert & Associates.