In cellular mobile phone systems, which is the main reason for dividing the service area into many small areas (cells), each with its own base station?

Answer: C. Because the same frequencies can be reused in cells far apart, so limited spectrum can serve many terminals

Usable spectrum is limited, so if one base station covered a wide area, few terminals could communicate at the same time. A cellular system divides the area into many cells and reuses the same frequencies in cells far enough apart not to interfere, increasing total capacity. When a terminal moves across a cell boundary, a handover passes the connection to the neighboring base station. In busy urban areas, making cells smaller (small cells) increases capacity further.

• A. Dividing into smaller cells increases the number of base stations. The scheme is for capacity, not cost.
• B. Crossing a cell boundary requires a handover to switch base stations.
• C. Correct. Frequency reuse increases the capacity of the whole area.