  With the seamless coverage of wireless cellular networks in modern society,
it is interesting to consider the shape of wireless cellular coverage. Is the
shape a regular hexagon, an irregular polygon, or another complex geometrical
shape? Based on fractal theory, the statistical characteristic of the wireless
cellular coverage boundary is determined by the measured wireless cellular data
collected from Shanghai, China. The measured results indicate that the wireless
cellular coverage boundary presents an extremely irregular geometrical shape,
which is also called a statistical fractal shape. Moreover, the statistical
fractal characteristics of the wireless cellular coverage boundary have been
validated by values of the Hurst parameter estimated in angular scales. The
statistical fractal characteristics of the wireless cellular coverage boundary
can be used to evaluate and design the handoff scheme of mobile user terminals
in wireless cellular networks.
