QoS routing with outdated network knowledge

The problem of QoS routing in an inaccurate link state is studied. In particular, the efficiency of different link cost functions are compared in a realistic environment where the link state changes are not immediately communicated to all nodes in the network. The effects of predicting the present network state when a node must make a routing decision are also analysed. For this purpose, an optimistic and a pessimistic prediction are considered, together with a combination of these two assumptions through a multi-path search policy.