BTS is a piece of equipment that facilitated wireless communication between user equipment and network. The devices like mobile phone, WLL phone, computer with network connectivity, WiFi.

This is generally associated between mobile phone like GSM CDMA. It is may use to encrypting or decrypting  communication.

The Base Transceiver Station (BTS) is a term used to denote a base station in GSM terminology. A BTS consists of an antenna and the radio equipment necessary to communicate by radio with a Mobile Station (MS). Each BTS covers a defined area, known as a cell. A BTS is under control of a BSC, which is in turn under control of a MSC (Mobile Switching Centre).