As the user moves from cell to cell, the call is handed off from one antenna to the next. Large PCS service areas also allow for wider roaming, and new data services linked to the Internet. Since wireless radio waves are transmitted over airspace a limited public resource instead of wires, the government must sell the space to mobile services providers. It has held a series of auctions to sell the rights to new frequency bands as they are introduced into service. For example, analog cellular services operate on the 800 MHz band, while PCS operates at the 1900 MHz frequency.
Cellular services are a deep-pocketed company s game.
After paying billions of dollars for their frequency licenses, wireless companies must invest billions more to build the infrastructure that the service actually runs on. The companies building these networks don t expect them to pay off for a decade or longer. There are also expensive mobile switching centers, which connect all the cell cites in a geographic area. In big cities, there are extra costs such as leasing rooftop space for antennas on tall buildings. Marketing is another big expense.