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| Radio-waves~ are divided-up into three categories: 1) Short-wave (emergency-dispatching) 2) Ground-wave (FM/AM Radio) 3) Long-wave (T.V./Cell-phones) |
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| The frequencies~ in which modern-day IR communication-technologies' work: 800-1000 nm |
Local dispatching-agencies use (short-wave) water-towers < to communicate with police-officers' on the beat.
