DISTRIBUTED SOFT HANDOFF IN All-IP WIRELESS NETWORKS

Two key problems need to be solved in order to realize soft handoff in wireless IP (Internet Protocol) networks: 1) Data distribution: multiple streams of the same IP traffic have to be distributed via multiple wireless base stations to the same mobile station, 2) Data content synchronization: pieces of data arriving at the mobile station at the same time from different base stations should be copies of the same data for the mobile station’s radio system to correctly combine the pieces into a single copy. Solving these problems in a distributed all-IP wireless network remains a challenge. This paper presents a new solution that consists of two main components: 1) a method that uses shadow addresses to realize data distribution with little signaling and 2) an IPlayer procedure performed by base stations to ensure data content synchronization at the mobile station.