Wireless data involves modulating, or coding conventional binary data (1’s and 0’s) onto a radio frequency carrier. The wireless data is transmitted as a radio message, comprising:

• Data
• Information that controls the message handling
• A “Lead-in” transmission at the beginning of the message to allow receivers to identify the type of radio transmission and to lock-on and synchronize with the transmitter.

Data can be modulated using a variety of techniques. Receivers de-modulate the radio message to re-create the original data. This process is of MOdulating and DEModulating describes the process that occurs in the hardware device MODEM.