On the contrary, most of WiMAX access points locate in
urban area where interference from other applications of
unlicensed bands is much more often. To reduce chance of
interference in urban area, limited usage of RF band is
necessary. Thus, TDD is a better choice while resource of RF
band is limited. Meanwhile, WiMAX access points preserve
shorter transmission distance than backbone network.
Therefore, the longer transmission delay of TDD than FDD
becomes insignificant because of the shorter transmission
distance in urban area.