PRIMARY TRANSFER FOR SIMPLEX MODE FORWARD-LINK HIGH-SPEED PACKET DATA SERVICES IN CDMA SYSTEMS

摘要

A back haul architecture enables efficient primary transfer (i.e., transfer of the designation of primary base station from one base station to another). A frame selection/distribution (FSD) function queues packets of forward-link data -- to which sequence numbers ha ve been assigned -- for packet-mode transmission over the back haul only to one base station -- the current primary base station -- where the packets are again queued for over-the-air transmission to the mobile unit. If and when it becomes appropriate to transfer the designation of primary ba se station to another base station, there may still be packets of data queued at the old primary base station awaiting transmission to the mobile unit. The old primary base station sends a messag e to the new primary base station indicating a particular sequence number that identifies the remaining packets of forward-link data queued at the old primary base station. The new primary ba se station then sends a message to the FSD function requesting transmission of those packets of forward-link data corresponding to the particular sequence number. The FSD function then transmits those requested packets of forward-link data to the new primary base station, which queues t he requested packets for over-the-air transmission to the mobile unit. In this way, transmission of all of the forward-link data to the mobile unit is enabled without having to transmit the remaining queued packets of forward-link data from the old primary base station to the new primary base station over the back haul, thereby providing an efficient mechanism for primary transfer in wireless communications systems that support forward-link data transmissions only in simplex mode.