Utility Max-Min Fair Congestion Control with Time-Varying Delays

Abstract

We present a framework for designing delay- independent end-to-end congestion control algorithms, where each end-user may have a different utility function. We only require that utility functions are strictly increasing. In this framework, we design an algorithm that maximizes the minimum utility value in the network, that is, the resulting resource allocation is utility max-min fair. To achieve this, we first extend the congestion control algorithm EMKC proposed by Zhang et al. [1], which aims at max-min fair bandwidth allocation. Our extension (xMKC) allows for arbitrary rate allocations in the steady state. We investigate xMKC analytically and prove local asymptotic stability with heterogeneous time-varying feedback delays in multi-link networks and global asymptotic stability with homogeneous time-varying feedback delays in single-link networks. Then, we propose uMKC (Utility Max-Min Fair Kelly Control), which achieves utility max-min fairness in its steady state. Based on the analysis of xMKC, we establish stability results for uMKC in the presence of time-varying feedback delays. Finally, we evaluate the performance of uMKC using NS-2 simulations [2].