Dynamic rate-based borrowing scheme for QoS provisioning in high speed multimedia wireless cellular networks

摘要

The provisioning of QoS in wireless networks carrying multimedia traffic imposes a big challenge to network designers and traffic engineers. Guaranteeing QoS in wireless networks is a complicated task due to the unique characteristics of wireless networks such as user mobility, limited link capacity, frequent link failure, scarcity of bandwidth, channel fading, and inability to predict the availability of resources in the network. In this paper, we investigate multiple QoS schemes in multimedia wireless networks. A modification to an existing scheme, rate-based borrowing scheme, where the concept of borrowing bandwidth from existing connections to accept both new and handoffs connections is proposed. Unlike Rate-Based Borrowing Scheme (RBBS) and Statistical Scheme (SBS), Dynamic Rate-Based Borrowing Scheme (DRBBS) exploits the positive feature of fair borrowing bandwidth and avoids pre-allocation of resources. This is based on the concept of borrowing from existing connections. Extensive simulation experiments have been performed using a simulation package designed for the purpose of this research. Using the call dropping/blocking probabilities and bandwidth utilization as a performance metrics, the proposed scheme, DRBBS outperforms the previously known schemes in terms of the aforementioned performance metrics. Fair borrowing from ongoing connections shows a decrease in the rate of calls dropping probabilities and a decrease in the calls blocking probabilities, while avoiding pre-allocation of resources offers a significant improvement in the bandwidth utilization.