Freedom R8100 SERIES, Operator'S Manual

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2.2.7.4 PROJECT 25 Test Mode (Trunking)
The optional R8100 P25 Trunk Test Mode allows testing of trunked APCO Project 25 (P25) compliant
radios. P25 mobile stations (radios) use a digital transmission format employing Continuous 4 level FM
(C4FM) modulation. The R8100 P25 Trunk mode simulates the functions of a Project 25 central controller
with the control and voice channel protocols needed for various tests. The simulation can be configured
to generate C4FM as well as LSM (Linear Simulcast Modulation) and WCQPSK (wide Continuous
Quadrature Phase Shift Keying). Also included are TIA/EIA-102.CAAA compliant test patterns for Bit
Error Rate (BER) testing, Frequency Error and Power meters, an Eye Diagram with graphical
representation of the P25 signal, and modulation signal quality meters.
A Voice Loop feature (U.S. patent 5703479) is engaged for audio verification of the radio’s end-to-end
operation after the subscriber unit transmits. During a Voice Call the R8100 automatically records voice
channel data while the subscriber unit PTT is pressed, then retransmits it to provide audio verification of
the radio’s end-to-end operation.
The manufacturer’s Radio Service Software (RSS) is required to perform some tests in P25 Trunk mode
because certain measurements (BER) require placing the radio in a special test mode. Figure 3.2.8.5-1
shows the R8100 main screen after choosing the P25 Trunk Test Mode.
As usual, the RF Zone can be used to configure various settings such as output level, attenuation, and
ports, etc. However, the soft keys for Monitor and Generate frequencies are disabled. These frequencies
are determined by settings in the P25 Trunk zone, either the control/voice channel frequency settings or
the control/voice channel number settings according to the Band Plan Table.
Note: RF Zone Monitor and Generate frequency settings can be changed for the BER Test. Otherwise,
they are read-only and updated in real-time to show the control channel frequencies or the voice channel
frequencies that are in use.