User Manual

14221-1200-2000, Rev. A
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6.16 WIDE AREA SYSTEM SCAN (TRUNKED ONLY)
The Unity mobile radio can be programmed for Wide Area System Scan (WA Scan) operation for multi-
site applications. Upon the loss of the currently selected system's control channel, radios can be
programmed to automatically scan the control channels of other systems. If a new control channel is
found, the radio switches to the new system and sounds an alert tone.
If the radio cannot find the control channel of the selected system and begins WA Scan, the radio only
scans for the priority system control channel if the priority system is in the WA Scan list.
1. Press MENU and then use the
ramp control to scroll through the selections until SYS SCAN
is displayed.
2. Press MENU to toggle the System Scan state.
3. The SYSC ON or SYSC OFF display message is displayed for two seconds to show the new state.
6.17 PROSCAN
The radio can be programmed for ProScan system scan operation for multi-site applications. ProScan
provides the radio with the ability to select a new system for the radio to communicate on when the
selected system drops below a predefined level. This is accomplished by enabling each radio to analyze
the signal quality of its current control channel and compare it with the signal quality of the control
channel for each site in its adjacency scan list. The signal quality metric used for the ProScan algorithm is
based on a combination of both Received Signal Strength Indicator (RSSI) and Control Channel
Verification (CCV) measurements. When the selected system’s signal quality level degrades below a pre-
programmed level, the radio begins to look for a better control channel. Once a control channel that
exceeds the pre-programmed parameters is found, the radio changes to the new system and emits a tone.
If the control channel is completely lost, the radio enters Wide Area System Scanning and searches the
programmed adjacent systems until a suitable control channel is found.
6.18 PRIORITY SYSTEM SCAN
The radio can also be programmed for Priority System Scan. To ensure that this feature operates
correctly, the control channel of the priority system must be located on channel one unless you are using
ProScan. The priority system is the desired or preferred system. While receiving the control channel of
the selected system, the radio periodically leaves the selected system and searches for the control channel
of the priority system at a programmable rate. The programmable rate is defined by the value in the
Priority Scan Time control, (unless ProScan is enabled, as explained below). This priority scan timer is
reset each time the PTT button is pressed or when a call is received. If the priority system control channel
is found, or meets the predefined ProScan criteria, the radio automatically switches to the priority system.
6.18.1 When Wide Area System Scan is Enabled
If the radio cannot find the control channel of the selected system and begins Wide Area System Scan
(WA Scan), the radio only scans for the priority system control channel if the priority system is in the WA
Scan list.
6.18.2 When ProScan is Enabled
The radio monitors the priority system and switches to the priority system if the priority system meets the
criteria defined in the “ProScan Options” dialog box. If ProScan is enabled, the rate at which the radio
scans for the priority system is defined by the System Sample Time control.