Offloading The Traffic Data From 2G, 3G Network Using WLAN Based On The Control Of PCRF

No matter in the home usage or in the commerce usage, Internet has taking a more and more important place. Currently, the 2nd generation(2G), the 3rd generation(3G) mobile communication and the WLAN (Wireless Local Area Network), which is uesd for high speed wireless access in a small area, have come into commercial applications. The study of choosing these access technique will enable the feasibility of the data traffic service of users.The combination of the 2G,3G and the WLAN has been researched for a while. WLAN is uesed to perfect the data access bit rate in a small area, especially the hot spot arae which the 2G,3G could not afford the data traffic. The method of loosely coupled system of WLAN and 2G,3G is not propitious for the management of the operators. So the paper is focused on the combination system based on the reuse of Gn refrence point and willing to supply a mechanism of offloading the data traffic to the WLAN from the 2G,3G system under the coverage area of WLAN.When the user is under service of a cellular system, the operation network needs to know the place where the user at. During the evolution of core network architecture, the 3 GPP has brought up the policy charging control mechanism and offloading the data traffic from the 2G, 3G system to the WLAN become possible. The paper designs a signal flow to enable the core network to support the downloading data traffic mechanism, and gives some simulation for the core network to judge how to make the credit rules.The traffic data access the PDN(Packet Data Network) through the GGSN in cellular network. We can update the GGSN to enable the deep packet inspection feature. Thus, some of the packet data that matchs the filter character could be downloaded to the WLAN. The operator could download some services with high traffic to the WLAN and keep the services with QoS requirement on the 2G,3G bearers. And this function will balance the load of the two networks, so that the performance of the two networks will match the requirement of the users.