whats difference between softhandoff & hardhandoff in WCDMA?

Question

softhandoff,hardhandoff,WCDMA

Answer 1

Hard handoff is similar to those used for the previous generations of systems. In this case, as the UE moves out of range of one node, the call has to be handed off to another frequency channel. In this instance simultaneous reception of both channels is not possible and there must be a physical break. Therefore the word "hard" handoff.

Soft handoff is a technique that was not available on the previous generations of mobile phone systems. With CDMA systems it is possible to have adjacent cell sites on the same frequency, and as a result it is possible for the UE to receive the signals from two adjacent cells at once, and they are also able to receive the signals from the UE. When this occurs and handoff takes place. Becuase there is no break, it is called "soft" handoff.

Handoffs are generally handled by the RNC. It monitors information regarding the signal strengths being received by both the UE and node B and when a particular link has fallen below a given level and another better radio channel is available, it initiates a handoff.