Overlapping Cells

Successful and smooth hand-offs can occur only if the coverage cells of adjacent access points overlap. For example, a person who is moving around while wearing a badge must be able to stay connected to the current access point while moving into the coverage area of an adjacent access point to ensure hand-off can occur without dropping packets.

A properly designed wireless network must provide cells with overlapping coverage on non-interfering channels, while simultaneously maintaining proper cell separation among access points using the same channel. Adequate cell overlap is required for smooth Basic Service Set (BSS) transitions.

The boundaries of access point coverage cells can change in real-time, as people and objects move around in the network environment. Some access points attempt to accommodate this situation by adjusting their power output dynamically.

Overlapping cells on the same channel result in:

• interference and dropped packets

• shared network bandwidth

• increase in noise flow

• decrease in signal-to-noise ratio (SNR)