Requesting An Over-The-Air Rekey; Mdc Otar (Conventional Only); Infinite Ukek Retention; Hear Clear - Motorola APX 8000XE User Manual

MN002667A01-AR
Chapter 6: Advanced Features
6.14.3.4

Requesting an Over-the-Air Rekey

If the Multi-system Over-the-Air Rekeying feature is in use, the rekey request is only for the current
selected secure profile.
Prerequisites:Ensure that the Unique Key Encryption Key (UKEK) or Unique Shadow Key (USK) is
loaded into the radio with the Key Variable Loader (KVL) before the rekey request can be sent. Refer
to your local key management supervisor for more information.
Procedure:
1 Press and hold the preprogrammed Rekey Request button to send the rekey request.
If the rekey operation fails, a bad-key tone sounds and the display shows RKY FAIL.
NOTICE: The rekey operation failure indicates that your radio does not contain the UKEK
or USK.
6.14.3.5

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.
NOTICE: This feature must be preprogrammed by a qualified radio technician. Contact your
system administrator for more information.
6.14.3.6

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.
NOTICE: This feature must be preprogrammed by a qualified radio technician. Check with your
dealer or system administrator for more information.
6.14.3.7

Hear Clear

Hear-Clear is a noise reduction system which composed 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.
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