User's Guide

Conventional Multikey
The encryption keys are strapped on a one-per-channel basis, through CPS. In addition, you can
have operator-selectable keys, operator-selectable keysets, and operator-selectable key erasure. If
talkgroups are enabled in conventional, then the encryption keys are strapped to the talkgroups.
Trunked Multikey
If both conventional and trunked applications are applied, strap the encryption keys for trunking
on a per-talkgroup, or announcement-group basis. Also, a different key can be strapped to other
features such as dynamic regrouping, failsoft, or emergency talkgroup. You can have operator-
selectable key erasure.
12.2.2
MDC OTAR (Conventional Only)
This feature allows you to view or define the Motorola Data Communications (MDC) Over-the-
Air Rekeying (OTAR) features. It is applied only when operating in secure encrypted mode. In
addition to Rekey Requests, OTAR transmissions include Delayed Acknowledgments, and Power-up
Acknowledgments.
Some of the selected options require configuration at the Key Management Controller (KMC) site to
work properly.
NOTE: This feature must be programmed by a qualified radio technician.
12.2.3
Infinite UKEK Retention
This feature enables Unique Key Encryption Key (UKEK) to be permanently stored in the radio even
when all the encryption keys are erased. Without this UKEK key, the radio cannot be rekeyed over the
air. The Infinite UKEK Retention settings can be different for each secure profile.
NOTE: This feature must be programmed by a qualified radio technician.
12.2.4
Hear Clear
Hear-Clear is a noise reduction system which consists of Companding and Random FM Noise
Canceller.
Companding
Reduces the channel noise, such as OTA transmission that is predominantly present in UHF2 and
900 MHz channel with the following features.
Compressor
Reduces the background noise flow and the speech signal at transmitting radio.
Expander
Expands the speech while the noise flow remains the same at receiving radio.
Random FM Noise Canceller (Flutter Fighter)
Reduces the unwanted effects of random FM noise pulses caused by channel fading under high
Signal-to-Noise (S/N) conditions such as in a moving transportation. The fading effects, heard as
audio pops and clicks, are canceled without affecting the desired audio signal.
The Random FM Noise Canceller operates only in receive mode.
NOTE: This feature must be preprogrammed by a qualified radio technician. Check with your
dealer or system administrator for more information.
MN009363A01-AA
Chapter 12 : Secure Operations
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