Cell phone layouts

     One of the most explosive areas of growth in recent years has been cell phone networks. Figure 1-10 shows an example of a handheld PDA that, along with making telephone calls, can transmit and receive data. The PDA has a modem installed, which transmits the PDA’s data across the cell phone network to the cell phone switching center. The switching center then transfers the PDA’s data over the public telephone network or through a connection onto the Internet. Many newer handheld devices have combined data accessing capabilities with a cell phone and can transfer data over cell phone connections.

An example of a user with a smart cell phone transmitting and receiving data