CELL-PHONE TECHNOLOGY - WikiEducator

CELL-PHONE TECHNOLOGYW ireless phones which receive their signals from towers. A cell is typically the area (severalmiles) around a tower in which a signal can be phones provide an incredible array of functions. Depending on the CELL-PHONE model, youcan: Store contact information Make task or to-do lists Keep track of appointments and set reminders Use the built-in calculator for simple math Send or receivee-mail Get information (news, entertainment, stock quotes) from the internet Play games Watch TV Send text messages Integrate other devices such as PDAs, MP3 players and GPS receiversA cell phone is afull-duplexdevice. That means that you use one frequency for talking and asecond, separate frequency for listening. Both people on the call can talk at of a city into smallcellsallows extensivefrequency reuseacross a city, so thatmillions of people can use cell phones phones operate withincells, and theycan switch cells as they move around. Cells give cell phones incredible range.

of fixed-line analogue telephone systems, the PSTN is now almost entirely digital, and now includes mobile as well as fixed telephones. 3. If you have a cell phone, you turn it on and someone tries to call you. Here is what happens to the call: • When you first power up the phone, it listens for an SID on the control channel. The

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