PTT is short for Push to Talk, or maybe you know it by the name 'Beep-beep' or 'chirp'. PTT is a conversation method between two devices, using a two way radio button to switch between a voice reception mode to a transmit mode.

Mobile phones are utilizing a full-duplex communication, which means that one can call another person to a land line or a cellphone, and can simultaneously talk and hear the other person talking. This type of communication must start with dialing a phone number and the other person answering the call, and the connection stays active until one person ends the call or until the connection is dropped because of a lost signal.

With two way radios it's totally different. you can send transmits without the need of dialing first. This is possible because two way radios use separate frequencies for transmission and reception.

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Cellular push to talk service adds much more functionality to the usual cellular services, because it allows transmissions to be sent to another person without the need of a connection to be already establish.

With PTT only one person can transmit at a time because the PTT service system is half-duplex (utilizing a single frequency), and so one personcan't transmit until the other person stops pressing thePTT key and stops the transmission. This can be very annoying…from experience! Sometimes you really want to comment on what the other person is saying, but you can’t!

Another important fact is that you can only use the PTT service within the same carrier. In other words, if you have a cingular wireless you can NOT talk on the radio with someone that got a Sprint Nextelservice (and that sucks!), but, according to the rumors anyway, the carriers are now considering changing that, so it will be possible in the future.

Oh, but the best part about the Push to talk service is that it does not count as airtime minutes that are used for regular voice calls. And how cool is that?

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