RF Power Terminology

[notes]
dB - attenuation/amplification of the power level - expressed as the base 10 logarithm of the ratio of the power of two signals, as shown here:

• dB = 10 x Log10 (P1/P2)

dBi - power gain rating of antennas
dBm - uses same calculations as dB, but has a reference value of 1mW.  Can also describe receiver sensitivity in -dBm.

Data networks: AP separation of 120-130 feet
Voice networks: cell edge at -67dBm, 2 non overlapping APs at an RSSI +35
                             baseline power of 35-50mw
                             requires 15% more APs than a 100mW deployment

APs have an aggregate throughput less than the data rate because the 802.11 provides a reliable transport mechanism that ACKs all packets, thereby halving the throughput on the channel.