Traditional one-way paging helps people stay connected when they are not within reach of a telephone, but it can also be highly disruptive, as when a person is forced out of an important business meeting to find a phone when an important page has to be answered immediately. From a system perspective, this method of information delivery is very inefficient and can cause delay as more subscribers are added to the system. This is because one-way paging systems rely on a large-scale simulcast system in which each message is transmitted from every transmitting antenna within a service area simultaneously.

Two-way paging systems not only allow messages to be acknowledged and answered immediately, but employ techniques that allow them to operate at optimum spectral efficiency. Unlike one-way traditional paging systems, two-way systems can keep track of the location of the subscriber units, while selectively and locally broadcasting messages to specific subscribers. This frees up spectrum for use in over 95 percent of the rest of the network, enabling service providers to support more subscribers.

Two-way paging allows subscribers to immediately respond to paging messages directly from their pager. Two-way paging represents the first generation of narrowband Personal Communications Services (PCS) to be made available to the public as a result of spectrum auctions held by the Federal Communications Commission (FCC) that began in mid-1994.

By employing an outbound and an inbound channel, two-way paging systems can locate a subscriber before sending a message. This eliminates the need to simulcast,...