Walkie-talkies are small portable radios with both a receiver and a transmitter. They can both broadcast and pick up radio signals and make for an easy way to communicate when cellphone signals are not available.
Walkie-talkies are radios that both receive and transmit a radio signal. These two-way radios have both advantages and limitations. Their main advantage is that they are not dependent of a central network, unlike cellphones. This means you can communicate with a walkie-talkie in places with no cellphone coverage. They are still limited, since you can only talk with the people connected to the same channel, and a walkie-talkie's coverage is dependant on range. Walkie-talkies are push-to-talk, which means that you have to press a button to transmit your signal.
Most walkie talkies have a single speaker that allows for transmitting and receiving sounds; however, some models have separate devices. They transmit radio waves at the speed of light, 186,000 miles per second, so communication is nearly instantaneous.
Users can operate walkie talkies as a single pair, or in groups, if they are tuned to the same frequency, such as police, military units, emergency responders, public event organizers and businesses. If privacy issues are a concern, walkie talkies use open transmissions that can be easily intercepted. However, encryption capabilities are available, but generally reserved for military use.
Commercial types of walkie-talkies usually have two frequencies: FRS and GMRS. Channels 1 through 7 are shared by both frequencies, channels 8 through 14 are FRS-only, and channels 15 through 22 are specific to GMRS. If you're in a channel, you only receive the signal and listen to anyone talking on the channel at the moment. Walkie-talkies are still commonly used, mostly by small businesses, deployed soldiers and by people who go travel in the outdoors, where cellphone towers are nonexistent.