Because the dispatch uses one central frequency for all hatzolah calls whether it’s in the RL, the City, or upstate. The MDC 1200 signaling code allows members to hear only what’s necessary in their area. The MDC 1200 system will allow the members radio to unmute only when it hears a three digit code and the rest of the time it will be muted so they don’t hear calls that are unrelated to the area that they are in