Cell planning is similar to the coloring problem. There is no frequency overlap between different PCS providers. Each cell can have a maximum radius of 20 miles. Want to minimize co-cells interference. Can use a simple 7 color scheme.
Power management can help delimit cell boundary.
Cell planning is not easy, need to watch for hills and buildings. GSM separates receive and transmit channels. A channel is a carrier number plus a slot number. Can use voice silence detection to improve system performance, but can't use voice silence detection to give the bandwidth to others. Offset by 3 so that it doesn't need to receive and transmit at the same time.