Fair Packet Scheduling and Bandwidth Management in Wireless Networks

Download or read book Fair Packet Scheduling and Bandwidth Management in Wireless Networks written by Ying Jian and published by . This book was released on 2008 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: ABSTRACT: Our study focused on fair packet scheduling and bandwidth management in CSMA/CA based wireless networks. We address the fairness problem for MAC-layer links and study end-to-end service differentiation and rate assurance for multihop flows. Fine-level rate control, particularly meeting rate requirements and differentiating various types of end-to-end traffic, remains an open problem for multihop wireless networks. Traditionally, rate assurance in wired networks is achieved through resource reservation and admission control, which can be efficiently implemented since the bandwidth capacity of each communication link is known and the sender of a link has the information of all flows that compete for the bandwidth of the link. In a wireless network, however, the capacity of each wireless link can change unpredictably over time due to contention from nearby links and dynamic channel conditions. An end-to-end flow consumes available bandwidth not only at links on its route but also at all nearby contending links, which makes resource reservation extremely complicated. We propose a new adaptive rate control function based on two novel techniques, called proportional packet scheduling (PPS) and dynamic weight adaptation with floor and ceiling (DWA). PPS distributes channel bandwidth among MAC (one-hop) flows in proportion to their weights. DWA adapts flows' weight according to their rate requirements and priorities. End-to-end traffic is classified into two categories: best-effort flows and QoS flows with rate requirements. The QoS flows are assigned with different priorities. PPS and DWA together achieve three important objectives without resource reservation and admission control. First, when bandwidth contention arises, the rate requirements of the QoS flows are satisfied in the order of priorities.