the invention supports two types of handoffs . the first handoff is for an inter - an cell selection where the source an allows the at to add a cell under the control of a different an to its active set and then allows the at to switch to the target an . a bearer path is established between the source and target an to transfer the packet data traffic using an exchange of messages to register the at &# 39 ; s movement from one bts to another bts . the a 8 / a 10 connections remain anchored at the source an and , hence , a bearer path is needed between the source and target an to transfer the packet data traffic . the second handoff occurs when the source an specifies a move of the at to a new an proactively . new connections are established at the target an to support the at , and the at is subsequently moved to the target an via the relevant air - interface messaging .