Q4if Diwania city center has an area of 25 square miles and is covered by cellular system using four cells reuse pattern. Each cell covers half square mile and the city is allocated 60 MHZ which uses two 30 kHz simplex channels to provide full duplex voice and control channels as a communication engineer calculate:
1. number of cells to cover all the city
2. No. channel per cell
3. Total capacity
4. determine the control channels and voice channels in each cell If 1 MHz of the allocated spectrum is dedicated to control channels
Answers
A certain city has an area of 1,300 square miles and is covered by a cellular system using a seven-cell reuse pattern. Each cell has a radius of four miles and the city is allocated 40 MHz of spectrum with a full duplex channel bandwidth of 60 kHz. Assume a GOS of 2% for an Erlang B system is specified. If the offered traffic per user is 0.03 Erlangs, compute (a) the number of cells in the service area, (b) the number of channels per cell, (c) traffic intensity of each cell, (d) the maximum carried traffic, (e) the total number of users that can be served for 2% GOS, (f) the number of mobiles per unique channel (where it is understood that channels are reused), and (g) the theoretical maximum number of users that could be served at one time by the system.
Solution (a) Given: Total coverage area = 1300 miles, and cell radius = 4 miles The area of a cell (hexagon) can be shown to be 2.5981R2, thus each cell covers 2.5981 × (4)2 41.57 sq. mi.