Radwin Transportation FiberinMotion - Basic Situation; Necessary Pre-Conditions

FinMDeploymentGuide Release4.5.10 4‐18
BasicSituation ConfiguringtheRadioNetwork
• Ifyoursystemusesmorethan3frequencies,thismethodofinterferencemitigationis
notneeded.
4.5.1BasicSituation
ThethreefrequenciesareusedontheTBSsinastaggeredfashion:TBS1usesF1,TBS2uses
F2,TBS3usesF3.Thepatternisthenrepeated:TBS4hasagainF1,TBS5hasF2,TBS6hasF3,
andsoon.
WeassumethatthenominaldistancebetweeneachTBSisatleast500m(belowground;
abovegroundthisvaluecanbeaslargeas2000m).SeeFigure 4‐10.
Figure4‐10:Co‐ChannelNeighbors
Atagivenmoment,arailcar(withTMU1)issynchronizedwithTBS1,andusingfrequencyF1.
Atthissamemoment,thisrailcarisabout1500metersawayfromTBS4,whichisalsousing
F1
1
.
AnysignalthatTMU1receivesfromTBS4atthispointisconsideredinterference.Ifthesignal
fromTBS4isstrongenough,theinterferencecanharmthethroughput,andneedstobe
mitigated.
Thissituationcontinuesthroughouttheline‐TBS7caninterferewithTBS4/TMU4,andinturn
TBS4caninterferewithTBS7
/TMU7.TBS7canfurtherinterferewithTBS10,TBS10can
interferewithTBS7andTBS13,andsoondowntheline.
Thetwounitsthatcaninterferewitheachotherarecalled“co‐channelneighbors”.
4.5.2NecessaryPre‐Conditions
Ifthe“Co‐ChannelNeighborInterferenceMitigation”optionisconfigured,itwillbeactivated
orde‐activatedautomaticallyaccordingtotheconditionsdescribedbelow.Notethatthe
activationconditionsandde‐activationconditionsarenotexactlysymmetrical.
1. Iffewerthan3frequenciesareused,thevalueswouldbe1000mfortwoand500mforonefrequency.
TBS1
TBS4
TBS7
TBS2
TBS3
TBS5
TBS6
TMU1
TMU4
TMU7
500m
500m
500m
500m
500m
500m
co‐channelneighbors
co‐channelneighbors