Subject: Mobile Computing

Difficulty: Medium

Marks: 4 Marks

Techniques for improving coverage and capacity of celluar system are:

Cell Splitting:

• It is the process of subdividing a congested cell into smaller cells,
• It increase the capacity of cellular system line it increases the number of times channels are reused.
• By defining new cells which have smaller radius than original cells and by installing by these smaller cells (microcells) between existing cells.

Fig: Cell Splitting

• Sectoring uses directional antenna to control interference and frequency reuse.
• A cell is normally partitioned into 3 sectors or 6 sectors.

Coverage zone (Microcell concept):

• When sectoring is employed, lot if handoff is required due to this load on switching and control link element of the mobile system increases. To solve this, a microcell concept for seven cell reuse is used.
• Each of three zones sites are connected to single base station.
• Zones are connected by co-axial fibre optic cable or microwave link to a base station.