How does Dual band service work?
Before PCS, all cell phones were single band devices that operated only in the Cellar 800 band. When service providers started to deploy both Cellular band and PCS band service, the cellular phone manufacturers started to make dual-band phones. These phones constantly report the signals and channels that are receiving to the towers, even when there is no call engaged. Based on this information the network sends commands back to the phones that include which tower to communicate with and which band to communicate on. This allows the service provider to make the cell phone operate on the PCS band when the provider wants it to and to operate in the Cellular band when no PCS signal is reported by the cell phone.
