Mdc Otar (Conventional Only); Infinite Ukek Retention; Hear Clear - Motorola APX 2000 User Manual

• Press the PTT button again, or the
in normal mode.
If the rekey operation fails, you hear a bad-key tone and the display shows Rekey fail.
NOTE: The rekey operation failure indicates that your radio does not contain the UKEK
or USK.
7.18.3.7

MDC OTAR (Conventional Only)

This feature allows you to view or define the Motorola Data Communications (MDC) Over-the-Air
Rekeying (OTAR) features. This feature 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. For more information,
contact your system administrator.
7.18.3.8

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. For more information,
contact your system administrator.
7.18.3.9

Hear Clear

Hear-Clear is a noise reduction system that 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 programmed by a qualified radio technician. For more information,
contact your system administrator.
or Emergency button, to exit the feature and transmit
68012005014-HV
Chapter 7 : Advanced Features
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