Handoffs

CDMA2000 systems utilize several types of handoffs for both voice and
packet data. The types of handoffs involve soft, softer, and hard. The difference
between the types is dependent upon what is trying to be accomplished.
The process for having a call or packet session in handoff for soft, softer, or hard is the same as that used for IS-95. The key exception to this
fact is when a packet session is in progress and the subscriber exits the
PDSN coverage area, resulting in a termination of the packet session.
There are several user, adjustable parameters that help the handoff
process take place. The parameters that need to be determined involve the
values to add or remove a pilot channel from the active list, and the search
window sizes. There are several values that determine when to add or
remove a pilot from consideration. In addition, the size of the search window
cannot be too small or too large.
When introducing CDMA2000 into an existing IS-95 system, the choice
of how to set up the neighbor list and search windows should mirror the
existing system except where there is a transition zone.