Impact of wind-induced fading on the capacity of point-to-multipoint fixed wireless access systems

• Authors: Yonghong Zhang;David G. Michelson
• Venue: Proceedings of the 2006 international conference on Wireless communications and mobile computing
• Year: 2006

The tendency for wind blowing through foliage and related environmental disturbances to cause fading events on nonline-of-sight fixed and stationary wireless channels has been well studied in recent years. However, the implications of such fading for the performance of point-to-multipoint wireless communications systems has apparently not been considered previously. Here, we present preliminary measurement data from a suburban macrocell environment which shows that: (1)fixed wireless links tend to exhibit highly variable behaviour over time with periods of calm interleaved with well-defined fading events lasting tens of minutes to hours; (2)some links are more fragile than others and exhibit a greater range of fading behaviour; and (3)fading events on different links within the same cell tend to be correlated with each other. While advanced signal schemes such as MIMO technology can often mitigate such fading, many practical systems continue to employ conventional technology and are susceptible. We show how such fading could degrade the capacity of such systems and the throughput and delay experienced by users.