Unfortunately digital trunking is going to involve encryption modes that make scanner monitoring of those transmissions useless. DES is already becoming quite common, and with the advent of Project 25, it is likely that most digital trunking systems (especially those in public service will be runnning high level encryption (256 bit) or cipher by 2010. Given the mandate deadlines for implementation thanks to stupid laws like the HSA, most agencies will have to capitulate in order to keep qualifying for federal funding, or else risk getting left behind and out in the dark for mutual aid ops.
It was bound to happen sooner or later. I must've retrofitted thousands of trunked portables in central Washington with DES boards, and that was 5 years ago.
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The ultimate result of shielding men from the effects of folly is to fill the world with fools.
-- Herbert Spencer, English Philosopher (1820-1903)