Understanding POCSAG

POCSAG is the most widely used paging protocol worldwide. It sends tone, numeric or alphanumeric messages over a one-way radio link. The protocol uses binary frequency shift keying, switching between two frequencies to represent a logical zero and one. Data rates of 512, 1200 or 2400 baud are supported. Each pager is identified by a unique cap code. Transmissions begin with a preamble, followed by a frame sync codeword and one or more batches. Each batch contains eight frames with two codewords each: address codewords identify the pager, message codewords carry the content. Testing typically covers RF performance such as sensitivity and selectivity, as well as power consumption in active and standby modes