By using  different antenna heights [often in the same building or tower] And different power levels, it is possible to provide large and small cells which are co located at a single location. This technique is called umbrella cell approach.

The fig above illustrates an umbrella cell which is co …

Umbrella cell approach:

The cell with low traffic speed is called as micro-cells and large high-speed traffic called macro-cells.

A hexagonal cell method is one of the closest approximation of a circle device. It is being typically used for the system.

The smaller cell is grouped and assumed to be …