Question: Suppose a 2.4 GHz transmitter is separated 35 m from the receiver. The signal must pass 5 m office (free space), then a wall with a 6 dB attenuation and the rest 30 m is an open area with a loss exponent of 3.1. Suppose isotropic transmitter which radiates 20 dBm. What should be the sensitivity if a receiver? Answer: Transmit power = 20 dBm - Free space loss LdB = 32.4 +20 log10(d[km]) + 20 log10(f[MHz]) = 54 dB Wall attenuation = 6 dB Open area losses L=10logo 3 (1) Required sensitivity = -66.2 dBm P.(d) P, (d) =10 log10 =10 logi 35 5 3.1 = 26.2 dB