Telecommunication networks include repeaters that serve to monitor the condition of each line within the network, and a center that dispatches repairmen to fix broken repeaters. In such a set-up, however, a problem arises : where is the most effective location for the center? First of all, we consider the network problem in which the nodes are the telephone offices and the arcs are the transmission lines. Here we deal with the center location problem in which the center must be located at a node and calls for service are assumed to occur on the arcs. This thesis proposes to prove that this problem can be transformed into a 1-median problem. Furthermore, the transformed problem will be proven to be equivalent to the center location problem that minimizes the sum of the distances weighted by the degrees of each node.