Performance Evaluation of Tcp Congestion Control Algorithms over Umts

TCP congestion control was designed and optimized for wired networks. During recent years, however, the popularity of wireless network infrastructures enabling ubiquitous Internet access, such as Universal Mobile Telecommunication System (UMTS), has grown considerably. As a consequence, many improved TCP congestion control algorithms, able to effectively operate over hybrid wired/wireless networks, as well as, layer 2 optimizations, hiding to higher layers the inefficiencies of radio links, have been proposed by the scientific community. This work investigates the performance of TCP congestion control over UMTS networks. We have focused the attention on the interactions between UMTS RLC error recovery, and New Reno or Westwood+ TCP congestion control algorithms. Using the ns-2 network simulator, we have shown that a proper tuning of RLC parameters can ensure an efficient usage of the UMTS wireless channel.