SELECTIVE CALL SYSTEM

PURPOSE:To prevent surely mis-calling between zones by transmitting a signal added with a scramble code in an optional bit of a selective call signal with prescribed logical operation from a base station to allow a receiver to operate inversely the scramble code. CONSTITUTION:The selective call number and message information from a subscriber telephone set are received by a base station of the selective call system, and the coder codes the call number and the message into an information bit (16-bit) comprising an individual number code (11-bit) and a message (5-bit). A check bit in 15-bit is added to the information bit 16, a scramble code (A) in 4-bit is added to the end while exclusive OR operation is applied and the result is transmitted. Then the receiver provided with an inverse logical operation circuit 10, a scramble code operation circuit 11, a ROM5, an error correction operating circuit 3 and a collation circuit 4 operates inversely the transmitted scramble code to prevent mis-calling between zones.