It is important when talking about wireless personal area networks, or any RF wireless protocol, to consider the range of transmission. Competing protocols use range, speed, and power as differentiators. As architects, we need to consider different protocols and design choices when implementing a complete solution. The range of transmission is based on the distance between transmitter and receiver antennas, the frequency of transmission, and the power of transmission.
The best form of RF transmission is unobstructed line-of-sight in a radio signal-free area. In most situations, this ideal model will not exist. In the real world, there are obstructions, reflections of signals, multiple wireless RF signals, ...
