Scalable gateway GPRS support node for GPRS/UMTS networks

In GPRS(General Packet Radio Service) and UMTS(Universal Mobile Telecommunications System) networks, GGSN (Gateway GPRS Support Node) serves as a default gateway while MSs (mobile stations) connect to outside networks such as Internet. According to GPRS/UMTS specifications, a fixed GGSN is assigned to serve an MS that attaches to the network and activates a session. The GGSN cannot be changed until the MS deactivates the session. Since packet-switched access is burst in nature, GGSNs may suffer from unbalanced load even the numbers of serving MSs of GGSNs are equal. This paper presents a GGSN relocation method that can re-direct in-service MSs without breaking services and connections. The proposed approach enables GGSN with a dynamical load balancing feature and improves the scalability of a GGSN system.