Meeting QoS requirements of mobile computing by dual-level congestion control

As the resources in a wireless network are limited and freely shared by all network users, Call Admission Control (CAC) plays a significant role in providing the Quality of Service (QoS) in wireless networks. However, when the network is congested with too many users, traditional CAC that mainly focuses on the tradeoff between new call blocking probability and handoff call dropping probability cannot guarantee QoS requirements to users. To address this issue, this paper proposes a dual level congestion control scheme which considers not only the call level admission control but also the user's decision to enter the network or not during the network traffic burst interval (we call it as user-level burst control). We adopt the economical terms of externality and introduce a total user utility function to formally model the user's perceived QoS metric. Our simulation shows that the weighted blocking probability (Pb) of our scheme can decreases 70-80% than traditional CAC systems and increase the total user utility to 2-3 times.