User's Manual Part 1

Designing a Fusion Wideband Solution
Page 64 InterReach Fusion Wideband Installation, Operation, and Reference Manual
© 2013 TE Connectivity Ltd D-620616-0-20 Rev H • TECP-77-044 Issue 7 • May 2013
DOWNLINKRSSIDESIGNGOAL
Wirelessserviceproviderstypicallyprovideaminimumdownlinksignallevelandanassociated
confidencefactorwhenspecifyingcoveragerequirements.Thesetwofiguresofmeritarea
functionofwirelesshandsetsensitivityandmarginsforfadingandbodyloss.Wirelesshandset
sensitivityistheweakestsignalthatthehandsetcanprocessreliablyandisacombinationofthe
thermalnoiseinthechannel,noisefigureofthehandsetreceiverfrontendandminimum
requiredSNR.Fademarginsformultipathfading(fastorsmall‐scale)andlog‐normalshadow
fading(sloworlarge‐scale)aredeterminedbythedesiredconfidencefactor,andotherfactors.
DownlinkRSSIdesigngoalcalculationsfortheGSMprotocolareshownbelowfora95%area
coverageconfidencefactor.
Downlinkdesigngoalsontheorder
of–85dBmaretypicalforprotocols,suchasGSM.Wireless
serviceprovidersmaychooseahigherleveltoensurethatin‐buildingsignaldominatesany
macrosignalthatmaybeleakingintothebuilding.
Noise Power
10 Log (KT)+10 Log (200 KHz); K=1.38X10-23, T=300 degrees Kelvin
-121 dBm
Wireless Handset Noise Figure 8 dB
Required SNR 9 dB
Multipath Fade Margin
95% Reliability for Rician K=6 dB
6 dB
Log-normal Fade Margin
95% Area/87% Edge Reliability for 35 dB PLS and 9 dB Sigma
10 dB
Body Attenuation + 3 dB
Downlink RSSI Design Goal (PDesignGoal)
Signal level received by wireless handset at edge of coverage area
-85 dBm