Handoff (or handover) is a control process initiated when a mobile moves from its current cell to its neighboring cell.
A user of a mobile phone will be moving continuously. In such a situation, the mobile connection should also remain intact especially if the user is currently using the phone.
This transfer of connection from one cell to another should be quick and in such a manner that user doesn’t actually realize that a handoff has happened.
There are four basic types of handoffs in GSM network:
a) Intra-cell handover:
- Such a kind of handover is performed to optimize the traffic load in the cell or to improve quality of a connection by changing carrier frequency.
b) Inter-cell handover:
- It is also known as Intra-BSC handover.
- Here the mobile moves from one cell to another but remains within the same BSC (Base station controller).
- Here the BSC handles the handover process
c) Inter-BSC handover:
- It is also called as Intra-MSC handover.
- As BSC can control only a limited number of cells, we might usually need to transfer a mobile from one BSC to another BSC.
- Here the MSC handles the handover process.
d) Inter-MSC handover:
It occurs when a mobile moves from one MSC region to another MSC.
MSC cover a large area. It can be imagined as a handover from Maharashtra MSC to Gujarat MSC while travelling.