MODEL 55B
Page Buffer

Digital Store and Forward Device

The Model 55B is essentially a recording device for storing pages received from a paging terminal for later transmission.

APPLICATIONS

Sequencing without zone addressing

When the coverage area of multiple remote transmitters overlap, interference can cause garbled or missed pages. Standard solutions to this problem include simulcasting and zone sequencing. Simulcasting requires expensive transmitters and control equipment. Sequencing is less costly, but some paging terminals are not capable of repeating pages with different zone addresses. By replaying pages from a remote link after transmission, the Model 55B provides a way to sequence overlapping transmitters without using zone addressing.

Remote control of shared channels

When the remote transmitter is being controlled via a simplex link such as RF or microwave, the remote site cannot notify the paging terminal when the channel is busy. This is a problem for shared paging frequencies, because the paging terminal might instruct a transmitter to key-up when the frequency is already in use. Because the Model 55B can monitor a receiver tuned to the paging frequency at the transmitter site, it can prevent transmission of pages when the channel is busy.

Paging terminals with no page storage

The Model 55B is an ideal add-on for a paging terminal with limited buffering capabilities. The Model 55B can store excess pages when the terminal or channel is already busy. This eliminates putting a caller on hold or sending a busy signal until the paging terminal or channel is free to receive new pages.

Paging terminals sharing remote transmitters

The Model 55B will allow two paging terminals to share one remote transmitter. By tying together two Model 55B Page Buffers at the transmitter site, each communicating with a different paging terminal, both terminals can page into one area without interfering with each other.

Analog paging channel repeater

The Model 55B can also be used to buffer analog pages from a receiver listening to the paging channel itself (eliminating the need for any link equipment). The pages are then retransmitted when the channel is clear. Since all transmissions on the paging channel are repeated, this only works when the paging channel is not being shared with other applications.
If digital pages need to be recorded from the paging channel, the Zetron Model 55D can be used because it interprets POCSAG 512 and 1200 baud pages, and stores them as digital data for retransmission.

Features

• Stores digital and analog pages from a paging terminal and forwards them to a transmitter when the paging channel is clear
• Eliminates need for costly zone sequencing or simulcasting equipment
• Allows remote control transmitters on shared channels
• Adds storage capability to older model paging terminals that cannot store pages
• Allows two paging terminals to share a remote transmitter
• Standard with 120 seconds of storage time, expandable up to 480 seconds

Specifications

PHYSICAL