How to Allocate Network Centers

This paper deals with the issue of allocating and utilizing centers in a distributed network, in its various forms. The paper discusses the signiicant parameters of center allocation, deenes the resulting optimization problems, and proposes several approximation algorithms for selecting centers and for distributing the users among them. We concentrate mainly on balanced versions of the problem, i.e., in which it is required that the assignment of clients to centers be as balanced as possible. The main results are constant ratio approximation algorithms for the balanced-centers and balanced-weighted centers problems, and logarithmic ratio approximation algorithms for the-dominating set and the k-tolerant set problems.