Numeric
Callers touch-tone dial a paging service, then enter in the numeric code--usually up to 20 digits--that will appear on the pager (typically the return phone number). The paging service then sends a signal to the local paging terminal, which transmits it via radio waves over the entire coverage area. The pager then alerts the pager owner with beeps or vibrations that a message is waiting.

Alphanumeric
The most common way to transmit text with an alphanumeric pager is to call the carrier operator, who then transcribes the message (typically up to 80 characters) to be sent to the pager. Other ways to send text include via modem or a dedicated alpha entry terminal.

Two-way
Two-way pagers use the PCS (Personal Communications Services) band recently auctioned off by the FCC. PCS relies upon low-power signals that are picked up by many small signal towers within a given region. Even a small pager can contain all the necessary PCS technology to receive and send messages.