Analysis of an enhanced signaling network for scalable mobility management in next generation wireless networks

In order to support new personal communication services (PCS) in 2.5G and 3G networks, the underlying signaling network must support scalable and fault-tolerant mobility management. A mobility management architecture based on multiple home location registers (HLRs) and multiple gateway GPRS support nodes (GGSN) can meet both of these requirements. We consider an enhanced network architecture in which the mobility management databases, in particular, the HLRs, are interconnected by a TCP/IP network. The primary function of this additional network interface will be to support synchronization of the replicated and/or distributed HLRs. We outline the architecture of the converged signaling network and discuss the integration with the GPRS network. We then present analytical models to quantify the benefit of distributed HLR and replicated GGSN architectures. Our results show that a distributed HLR architecture can reduce the update and query delay. Finally, by appropriately load balancing the multiple GGSNs, the mean packet delay can be significantly reduced.