Simulcasting

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How is it determined if a county is going to be Simulcast or Non-Simulcast.
It just looks like, to me @ least, that Simulcasting is a waste of spectrum. Why broadcast over the
whole statewide county system when just broadcasting/transmitting on a single
site can get the job done. Plus this frees up frequencies for other services.
 

WA0CBW

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It depends on the coverage area required. If a single site will not cover the area required then simulcasting is a method of extending the coverage area. Simulcasting is a technique that has been around for a long time. It uses the same frequency at all sites thus reducing the need for lots of frequencies. Also the user doesn't have to change the channel selector as they travel through the coverage area of each site. The disadvantages are tighter frequency control and timing and phase of the transmitted signal. RF in the overlap areas of multiple sites can be difficult to decode.
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wa8pyr

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How is it determined if a county is going to be Simulcast or Non-Simulcast. It just looks like, to me @ least, that Simulcasting is a waste of spectrum. Why broadcast over the whole statewide county system when just broadcasting/transmitting on a single site can get the job done. Plus this frees up frequencies for other services.
I think you're mixing up your terminologies here. Simulcast refers to a single site with multiple towers, all of which SIMULtaneously broadCAST on the same frequencies. Simulcast is typically used in metro areas which have a requirement for greater in-building coverage (like Columbus), or other less populated areas with considerable coverage challenges and a healthy traffic base (like Washington County). Simulcast sites can have up to 30 channels, and are more spectrum efficient in this context than multiple sites with multiple frequencies.

What you're referring to is Multicast, in which a signal is broadcast on multiple towers with different frequencies on an as-needed basis. This is a lower-cost option typically used to provide coverage in rural areas where there isn't much traffic; these sites typically have no more than 10-12 channels.

For both simulcast and multicast sites, radio traffic for a given agency is only present when a user radio is affiliated to that site.

The way these wide-area systems are configured, users can roam anywhere in the state and still be able to communicate back home. While the unrestricted use of this capability can be debated endlessly, it is a big help for interoperability, enabling units responding to a major incident from outside the area to monitor the incident and communicate with the command post earlier than they might otherwise be able to.
 
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