Fire Paging on the P25 Trunking system

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Nov 19, 2005
Relm Wireless has addressed the Paging dilemma on the P25 Trunked network, what they have done is utilize the call alert feature within the P25 standard feature set, the call alert is actually an individual Unit ID to Unit ID call type, but could be setup on any of the existing P25 consoles. In order to accommodate the one to many call type required for paging, Relm Wireless created the sentinel ID, so one single base station can be configured to appear to be many P25 Radios from the system level view, when the Base Station receives a call alert (Page) from the console it immediately acknowledges back to the console then refers to an internal lookup table which maps that individual sentinel ID to a predetermined DTMF ID that is programmed into the Relm BK Radios similar to the Quick call codes in a pager (Yes the solution would require the use of radios verses a receive only pager). The radios can be set to voice mute with the push of a button, so as to mimic the pager. The DTMF Id is sent out over the voice channel so the dispatcher has an audible when it is clear to talk. A second DTMF ID code can be programmed in the radio and can be mapped to the sentinel ID in the Base Station in order to mimic the All Call features as well.
Relm Wireless has gone on further to develop this same scenario in order to accomplish Station and weather siren alerting, the difference is that instead of mapping the sentinel ID to a DTMF code, it is mapped to an output of the Base Station which activates various functions within an existing alerting system.

Although this solution involves the utilization of a radio, Relm Wireless has been offering P25 Trunking portable radios in the $1200-$1500 range for years and the paging feature is part of the standard feature set, this is true with the Base Station as well, average Base Station cost is @$3500.
The drawback besides the increased cost (Radio Verses Pager) is the additional Unit ID's (Sentinel) which in many states is issued on a cost per month basis for voice traffic. Since a sentinel ID cannot be accessed by a user at the base station and be utilized for a voice communications in the normal sense, a cooperation would be necessary from the system owner/user community to work out a reasonable or no cost plan for the sentinel ID's.
For more information you can contact
Ken Klyberg
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