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New capabilities, tried-and-true technology
Cell phones might seem like the ultimate sign of the new millennium, but wireless communications rely on a technology that’s been around for more than 160 years.
Your cell phone sends information—whether it’s voice, text, images, music or more—in the form of radio waves, also called “signals” or “radio frequencies” (RF). This is the same technology that delivers radio and television broadcasts and that makes cordless telephones, baby monitors and wireless routers work in your home.
Cell phone calls travel by air and land
A wireless network operates on a grid that’s divided into geographic areas or cells. Within each geographic cell is a wireless facility or cell site that contains low-powered radio equipment required to send and receive calls.
A cell site uses transmitters and receivers, connected to antennas, to provide service within its coverage area. Ideally, the areas covered by each cell site overlap so a call can pass seamlessly from one cell site to another as a caller moves around.
When you make a call, your cell phone sends your voice or information via radio signals to the cell site serving your area. The cell site then forwards your call through the same infrastructure that landline calls use.
Your call goes to a central facility, called a switch, that identifies the destination for your call and forwards it via the public telephone network, the infrastructure that landline calls use. Your call will go directly to a landline phone or if it’s headed to another cell phone, it will travel to another switch, a cell site, and then be delivered to the cell phone via radio signal.
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