This timely book is a comprehensive treatment of managing mobility in wireless networks. Significant new insight is also provided into solutions to file allocation problems, specifically data replication, faced in distributed database systems by Computer Scientists. Some of the solutions are applications from the general facility location problems in Operations Research.
The authors thoroughly investigate replication for hierarchical mobility management where the underlying network forms a tree-like structure. Various problem formulations are considered that provide new insight into more comprehensive solutions. The off-line replication problem is reduced to problems in discrete location theory for which efficient dynamic programming solutions exist for tree networks. To solve the on-line replication problem, a unified framework is established that provides unique visual representation of the overall solution structure. This framework not only demonstrates the correspondence between two previously proposed on-line algorithms but also provides the basis for new algorithms and expands the applicability of the original problem formulation. All algorithms derived in this book have been implemented and simulated using realistic traffic models. Their performance is compared with previously proposed algorithms.
Mobility Management In Wireless Networks: Data Replication Strategies and Applications is an excellent reference for engineers, computer scientists, operations researchers and others working in mobility management as well as in related fields including distributed database systems, data management and facility location.

In wireless communication systems, the network keeps track of a user's location through an up-to-date user profile stored in various databases. A user profile contains not only a user's current location information, but also service information, such as billing and authentication. The cov- age area of an access network is divided into registration areas (RAs), and each RA is associated with a location database. The two basic op- ations in mobility management are location update and location lookup. When a user moves across the boundaries of these RAs, the network updates his location information in the pertinent databases. When a caller places a call using the callee's identification, the network queries the relevant database(s) to obtain the current location and other service information of the callee. The performance of mobility management can be further enhanced by using replicas of user profiles which may be kept at various locations. Replication techniques make profile information more readily available, thus reducing lookup cost and latency, but to keep these replicas c- sistent and fresh, they must be updated whenever the user profile is updated. The principle of replication is to replicate if the benefit of replication is greater than its overhead. The difficulty, however, lies in accurately measuring the benefit and overhead.