full duplex comm headset

Full duplex is a bidirectional type of communication system where two or more headsets send and receive voice signals at the same time, and a single carrier is simultaneously used for dual communication.  The headsets can be used to receive and send voice data at the same time.  No waiting real time conversation.  

  Digital Enhanced Telecommunications System (DECT) was originally intended for fast roaming between networked base stations, it is most widely used as a simple cordless phone system to connect phones to a base station or base point. The Bluetooth radio interface uses techniques: modulation; frequency hopping & protocols to ensure reliable & effective data transfer.

Gaussian frequency shift keying is the Bluetooth radio interface uses techniques:

Phase shift keying is the form of Bluetooth modulation used to enable the higher data rates achievable with Bluetooth protocols to ensure reliable & effective data transfer.