Long_line_PA Public_address_system

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london underground employee making long line public address system announcement using rpa01 radio microphone @ bank station


a long-line public address (llpa) system public address system distributed architecture, across wide geographic area. systems of type commonly found in rail, light rail, , metro industries, , let announcements triggered 1 or several locations rest of network on low bandwidth legacy copper, pstn lines using dsl modems, or media such optical fiber, or gsm-r, or ip-based networks.


rail systems typically have interface passenger information system (pis) server, @ each station. these linked train describers, state location of rolling stock on network sensors on trackside signaling equipment. pis invokes stored message play local or remote digital voice announcement system, or series of message fragments assemble in correct order, example: / / 23.30 / first_great_western / night_riviera_sleeper_service / / london_paddington / / penzance / .... / depart platform / 1 / train formed of / 12_carriages /. messages routed via ip network , played on local amplification equipment. taken together, pa, routing, dva, passenger displays , pis interface referred customer information system (cis), term used interchangeably passenger information system.








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