User's Manual

Table Of Contents
Advanced Features
English
76
Requesting an Over-the-Air Rekey
This feature, also known as OTAR, allows the dispatcher to
reprogram the encryption keys in the radio remotely. The
dispatcher performs the rekey operation upon receiving a rekey
request from the user.
Procedure:
1 > or < to REKY.
2 Press the Menu Select button directly below REKY.
3 Press the PTT button to send the rekey request.
OR
Press the PTT button again, or the H or Emergency button,
to exit the feature and transmit in normal mode.
4 If the rekey operation fails, a bad-key tone sounds and the
display shows REKEY FAIL.
Note: The rekey operation failure indicates that your radio
does not contain the Unique Shadow Key (USK). This
key must be 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.
The Global Positioning System (GPS)
This feature uses information from the Global Positioning
System (GPS) satellites orbiting the Earth to determine the
approximate geographical location of your radio, expressed as
latitude and longitude. The availability and accuracy of this
location information (and the amount of time that it takes to
calculate it) varies depending on the environment in which you
are using the GPS feature.
For example, GPS location fixes are very difficult to obtain
indoors, in covered locations, between high buildings, or in
situations where you have not established a clear broad view of
the sky.
Understanding the GPS Feature
The GPS technology uses radio signals from earth orbiting
satellites, to establish the location co-ordinates, maximizing
your view of clear unobstructed sky is essential for optimum
performance.
Where adequate signals from multiple satellites are not
available (usually because you cannot establish a view of a
wide area of the sky), the GPS feature of your radio will not
work. Such situations include but are not limited to:
In underground locations
Inside of buildings, trains, or other covered vehicles