Ec/Io CALCULATION

Ec/Io CALCULATIONEc/Io = Xp * Pc * T(r) . [No Bw]mob + Pc * T(r) * (1+ Y)Where, T(r) = [Lp (r) + Gb + Gm]Xp = Fractional Cell Power Allocated to the Pilot ~ 15% = 34.77 dBmPc = Cell Output Power ~ 20 Watts = 43 dBmGb = Cell Antenna Gain including Cable Losses = 6 dBGm = Mobile Antenna Gain including Cable Losses = 0 dBLp (r) = Maximum Path Loss = 110 dB[No Bw]mob = Thermal Noise at the Mobile ~ - 185 dBmT(r) = Maximum Transmission Loss = -116 dBYp = Ioc/Io = Other Cell / Serving Cell interference power spectral density ~ 2.5 dBPutting the values @ 110 dB Max Path Loss we get,Ec/Io = 34.77 + 43 - 116 + 185 - [116 + 43 + 3.5] Ec/Io = -15.73RSSI UNITS CALCULATIONRSSI Units = dBm + 130 0.78125Where, dBm always express with negative sign in the formula.For dBm = -55RSSI Units = -55 + 130 0.78125RSSI Units = 96

Note: In the cell site, receive signal strengths at the input to the voice radio are measured interms of RSSI units. The conversion example is explained above.The constant value ".78125" is obtained by dividing 100 by 128. 128 is the true constant and is the number of possible values represented in the range 0-127 which can be represented by seven binary bits.