Learn how text messages travel from cell phone to cell phone, in this episode of What the Physics?! from NOVA. Cell phones use antennae to transmit and receive radio waves that carry binary information. Every cell tower presides over an area of land, where it receives and transmits radio waves. When a text message is written, it is transmitted as binary code using a particular frequency of radio waves specific to that user. The signal is received by a nearby cell tower, which then directs the information to be transmitted by another tower near the intended recipient. Cell towers are connected by a network of computers that constantly monitor the locations of cell phones so that each phone can communicate with the tower closest to it. This resource is part of the NOVA: What the Physics?! Collection.
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