User's Guide

First InterComm ™ System User Guide
A29798 Page 5
November 2007
Trees/Buildings Weaken Signal
Hills/Buildings Can Block Signals
Optimal Range: Clear Line of Site!
Trees/Buildings Weaken Signal
Hills/Buildings Can Block Signals
Trees/Buildings Weaken SignalTrees/Buildings Weaken Signal
Hills/Buildings Can Block SignalsHills/Buildings Can Block Signals
Optimal Range: Clear Line of Site!
Figure 4. Area Geometry or Physical Features Can Affect Talk Range
Signal Relay (Hopping)
Figure 5 shows a generalized urban incident site where there is no LOS between
vehicles A and D or vehicles B and C. Figure 6 shows a generalized ex-urban incident
site where vehicles A and E have no LOS and are considerably farther apart than one-
quarter mile. In both scenarios, the FICS overcomes these limitations by “hopping”
voice communications; i.e., passing communications through the units that do have
LOS. Thus, all units can communicate even though not all have direct LOS.