Shannon's Law describes the relationship between bandwidth, signal power, and noise in determining the theoretical maximum Capacity in bits per second of a particular communications channel. A close approximation of Shannon's famous formula is:
C = .332 (Bandwidth) ( SNR) , where B=Bandwidth in Hz, and SNR is in dB.
(Signal to Noise Ratio (SNR) is the difference between the power of a particular signal and the level of background noise.)
1) What is the theoretical maximum data capacity of a WiFi channel with a bandwidth of 20MHz, Signal power of -60dBm and noise level of -100dBm? What is the Spectral Efficiency of this theoretical maximum throughput?
2) What is the theoretical maximum data capacity of a cellular/PCS channel with a bandwidth of 1.25MHz, Signal power of -70dBm and noise level of -90dBm? What is the Spectral Efficiency of this theoretical maximum throughput?