A report from ABI Research says that more work and important communications takes place indoors rather than out, and that propels the need for better wireless coverage inside.

"The combination of supply-side enablers -- 3G networks, handsets with advanced capabilities, mobile applications -- with a strong customer need means operators will be focused on establishing a coverage footprint inside buildings to retain customers who are using mobile data services," said principal analyst Dan Shey in a prepared statement. "We expect this market to show a compound annual growth rate of nearly 20% by 2011."

That's a good sign for companies that supply wireless equipment. ABI goes on to say that while the network operators have been working to extend their current networks into buildings, the results aren't good enough. Just this week I was at a meeting in Manhattan. Standing at a window on the 21st floor of a building two blocks from Times Square, my phone was giving me just one bar of coverage. When I moved into the core of the building (i.e., standing next to the elevators), my phone dropped to "SOS" mode. The macro network wasn't able to penetrate through all the walls in that building at that height. Network operators will have to look to other micro cell technologies to pick up where the macro network leaves off.

"Traditional DAS and repeater systems will still play a major role in establishing indoor coverage," says Shey, "but look for femtocells and picocells to play an increasingly important role, not only supplementing current in-building systems but also replacing them."