Subject : Mobile Communication

Topic : Cellular Communication System

Difficulty : Medium

Transfer of a Call from One Cell to other called as Handoff.
During handoff there is possibility of call block.

Following are the type of Handoff :

1) Hard handoff - During the handoff process, if the old connection is terminated before making the new connection, it is called a hard handoff .it can be further divided into intrafrequency and interfrequency handoff.
Interfrequency handoffs may occur between two different radio access networks, for example, between GSM and Universal Mobile Telecommunications Services. And In the 2G TDMA systems, the majority of handoffs are intra frequency hard handoffs

2) Soft handoff - The handoff is referred to as soft handoff if the new connection is established before the old connection is released. In the 3G systems, the majority of handoffs are intrafrequency soft handoffs.

3) Softer handoff - In softer handoff, the BS transmits through one sector but receives from more than one sector