Priority Service Provisioning and Max–Min Fairness: A Utility-Based Flow Control Approach

In this paper, a novel priority assignment scheme is proposed for priority service networks, in which each link sets its own priority threshold, namely, the lowest priority the link is willing to support for the incoming packets without causing any congestion. Aiming at a reliable transmission, the source then assigns each originated packet the maximum priority value required along its path, because links may otherwise discard the incoming packets which do not meet the corresponding priority requirements. It is shown that if each source sends the traffic at a rate that is reciprocal to the specified highest priority, a bandwidth max–min fairness is achieved in the network. Furthermore, if each source possesses a utility function of the available bandwidth and sends the traffic at a rate so that the associated utility is reciprocal to the highest link priority, a utility max–min fairness is achieved. For general networks without priority services, the resulting flow control strategy can be treated as a unified framework to achieve either bandwidth max–min fairness or utility max–min fairness through link pricing policy. More importantly, the utility function herein is only assumed to be strictly increasing and does not need to satisfy the strictly concave condition, the new algorithms are thus not only suitable for the traditional data applications with elastic traffic, but are also capable of handling real-time applications in the Future Internet.