P25 Encryption; Automatic Psu Revert To Talk Around (Ta); Digital Outbound Takeover; Table 15 P25 Inbound & Outbound Encryption Scenarios In Digital Mode - Futurecom Mobexcom P25 User Manual

P25 Encryption

The DVRS transparently passes the P25 encryption algorithms used by the subscriber
and fixed network equipment.
The DVRS can translate TG IDs (when TG Translation is enabled), however it can not
translate encryption keys.
Call From
Local PSU
CLEAR
ENCRYPTED
Call From
System PSU / MSU
CLEAR
ENCRYPTED
Table 15 P25 Inbound & Outbound Encryption Scenarios in Digital Mode

Automatic PSU Revert to Talk Around (TA)

The DVRS Enabled PSU (with firmware R09.00.00 or later) can be programmed to
automatically revert to TA if it goes outside of the DVR radio coverage range. The PSU
automatically reverts to normal full duplex operation as soon as it re-enters the DVR
radio coverage range.
If using a simplex DVRS channel, the simplex PSU can be programmed to automatically
revert to TA so that it can transmit even when the PSU is outside of the range of the
DVRS. This way, simplex PSU-to-PSU calls will be allowed regardless of the presence
or absence of the DVRS.

Digital Outbound Takeover

When Digital Outbound Takeover is enabled in the DVR, a local PSU call is given higher
priority over an ongoing outbound call as described below.
The DVR stops repeating the outbound call and starts repeating the LPSU call.
The DVR tries to key up the MSU and if channel grant is received, the inbound call is
repeated to the system. Typically the MSU can only get channel grant and key up if the
MSU is receiving on a different TG then the one selected on the LPSU. If the MSU is
receiving a call on TG A and the LPSU tries to key up on the same TG A, the MSU will
not be able to key up (Trunking System programmed for Interrupt = Never).
If TG Translation is enabled, the inbound LPSU call will always try to key up the MSU on
its selected TG. The LPSU will be unable to interrupt the receiving MSU due to Interrupt
Never setting on the trunking system.
The Digital Outbound Takeover operation depends on other system factors, such as
DVRS programming (Call setup options on the Digital System Setup screen), trunking
system programming and PSU type ('DVRS Enabled' or 'Generic P25') and its
programming.
For instance, if 'Pass Deny to PSU' is enabled (checked) in the DVR, then if the LPSU
receives a Deny, it will sound a deny tone, give up transmitting and will resume receiving
April 2014
DVRS / MSU Mode
CLEAR OR
SECURE
CLEAR OR
SECURE
DVRS / MSU Mode
CLEAR OR
SECURE
CLEAR OR
SECURE
Receiving
Local PSU System PSU / MSU
CLEAR
ENCRYPTED
Receiving
Local PSU
CLEAR
ENCRYPTED
8A083X20 Rev. 16
6881013Y38-P
User's Guide
Receiving
CLEAR
ENCRYPTED
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