Mumbai University > Computer Engineering > Sem6 > Mobile Communication and Computing

Marks: 5M

Year: May 2015

• 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.