An enhanced network architecture to support replicated HLR databases-prototype design and experimental performance analysis

In this paper, we consider an enhancement to the existing signaling system number 7 (SS7) network architecture in which the mobility management databases, in particular, the home location registers (HLRs), are interconnected by a TCP/IP network. The primary function of this additional network will be to support concurrency control of replicated HLR databases. Since additional bandwidth can be added to the TCP/IP network as required, a higher degree of replication can be supported than in the legacy narrow-band SS7 network. The enhanced signaling network also provides other advantages: 1) since the HLR databases can now be accessed through the Internet, they can be used to support mobility management for mobile-IP services; 2) the enhanced network will enable new types of mobile applications in which the location information of mobile terminals can be queried over the Internet; and 3) the additional network interface will allow more effective management and control of the HLR databases. In this paper, we outline the key aspects of the enhanced network architecture and describe a prototype implementation. Our preliminary results based on experiments on a local area network (LAN) show that when the network is not the bottleneck, a moderate degree of replication can be supported even with nodes with low processing capacities