VERTICAL HANDOFF METHOD AND SYSTEM IN WLAN/3G INTEGRATED NETWORKS

摘要

An IPSec tunnel is established by assigning parameters TS and SPI being translated into TFT (PF I, PF II). A first index is assigned. A GTP tunnel is established based on TFT (PF I, PF II) and the first index. GGSN generates a table based on TFT (PF I, PF II) and the first index, for UE in WLAN network to access 3G services. UE assigns a second index when roaming into the 3G network. A tunnel between SGSN and UE is established based on TFT (PF I, PF II) and the second index. Another tunnel between the SGSN and the GGSN is established based on TFT (PF I, PF II) and the second index. GGSN searches for the table with the first index based on SPI in the TFT (PF II), for reusing the table for not interrupting 3G services provided to the UE in the 3G network.