Radiopaging technology and systems for wide-area use

摘要

Paging systems have a continuing role to play in low-cost communication as improving technology shrinks the world. Pan-European and pan-global systems are now technically possible. Paging is one of the cheapest and most practical ways of keeping in touch while on the move. There are two types of system. The first, on-site (or in-plant) paging system which offers a service in a limited area, normally no more than 0.5km from a single transmitter, is widely used in commercial, industrial and retail environments. This article is about wide-area paging systems which may serve a city or an entire country. They first appeared in the USA in the 1960s.