APCO P25 Mode Operation
Key Fail Indication
The transceiver indicates “Key Fail” for the
specified time period* when the Common Key
Reference (CKR) of the selected channel is not
stored in the encryption unit.
Decryption Multi Keys function
When this function is enabled, the transceiver
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▒
NOTE: There are 2 models of KMM— Standard
▒
and Packet. If the pre-programmed KMM type
▒
is not matched to the system to which the
▒
transceiver attempts to register with, the
▒
registration attempt may fail. In that case,
▒
the transceiver’s KMM type should be changed
▒
to another type.
releases the mute after receiving the audio signals
for decryption, even if the CKR setting is not
matched to the selected channel.
*Depending on the pre-set time.
■
OTAR function
P25 Over-The-Air-Rekeying (OTAR) function
Deregistration from the OTAR system
➥
Push [CH Up] or [CH Down], or rotate
[CH Up/Down], to exit the channel in which the
OTAR function is enabled. After exiting the
channel, the transceiver automatically attempts
deregistration from the OTAR system by
transmitting a KMM ‘Deregistration’ command
P25 Over The Air Rekeying (OTAR) function
allows the Key Management Facility (KMF) to
change the encryption keys in a transceiver
remotely, (“over the air”) to protect the secure
communications. Moreover, several OTAR
commands are used to perform the following
operations. See also
4-7 OTAR
for this function.
From KMF to transceiver:
to KMF.
Rekey request function
Normally, the encryption keys are managed and
securely changed by KMF over the air without
receiving a Rekey request. But the transceiver
can control KMF remotely by sending a Rekey
request to perform the rekey operation.
• Change Active Keyset
• Change Group RSI
• Radio Check
- The transceiver automatically responds to any
command.
From transceiver to KMF:
• Registration to the OTAR system
D
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th OTAR
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1
Push and hold [Rekey] for 1 sec to send a KMM
‘Hello’ command to KMF for a Rekey request.
• “REQUEST REKE” appears.
2
After receiving a Rekey request from the
transceiver, KMF performs the rekey operation.
3
When the rekey operation is successful,
• Deregistration from the OTAR system
• Rekeying
- When the channel in which the OTAR function is
enabled is selected, the transceiver automatically
attempts registration to the OTAR system by
transmitting a Key Management Message (KMM)
to KMF. Various other commands are exchanged
“REQUEST REKE” disappears.
• If the rekey operation fails, “FAILED” appears.
Active Keyset selection
This function allows you to select the Active Keyset
that is stored in the transceiver.
The keyset structures a group of keys. By changing
the keyset, the group of keys will be automatically
between KMF and a transceiver, other than above.
Registration to the OTAR system
➥
Push [Zone], then push [CH Up] or [CH Down],
or rotate [CH Up/Down], to select the channel
in which the OTAR function is enabled.
After selecting the channel, the transceiver
automatically attempts registration to the
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switched to another group.
1
Push [Keyset] to enter the keyset selection mode.
• The selected keyset name (“KEYSET1” or
“KEYSET2”) appears.
2
Push [CH Up] or [CH Down], or rotate
[CH Up/Down], to select the desired keyset.
3
Push and hold [Keyset] for 1 sec to set the
56
automatically attempts registration to the
OTAR system by transmitting a KMM
‘Registration’ command to KMF.
3
Push and hold [Keyset] for 1 sec to set the
selected keyset.
4
Push [Keyset] to exit the keyset selection mode.