2,588 research outputs found
Distributed QoS Guarantees for Realtime Traffic in Ad Hoc Networks
In this paper, we propose a new cross-layer framework, named QPART ( QoS br>rotocol for Adhoc Realtime Traffic), which provides QoS guarantees to real-time multimedia applications for wireless ad hoc networks. By adapting the contention window sizes at the MAC layer, QPART schedules packets of flows according to their unique QoS requirements. QPART implements priority-based admission control and conflict resolution to ensure that the requirements of admitted realtime flows is smaller than the network capacity. The novelty of QPART is that it is robust to mobility and variances in channel capacity and imposes no control message overhead on the network
A Distributed Scheduling Algorithm to Provide Quality-of-Service in Multihop Wireless Networks
Control of multihop Wireless networks in a distributed manner while providing
end-to-end delay requirements for different flows, is a challenging problem.
Using the notions of Draining Time and Discrete Review from the theory of fluid
limits of queues, an algorithm that meets delay requirements to various flows
in a network is constructed. The algorithm involves an optimization which is
implemented in a cyclic distributed manner across nodes by using the technique
of iterative gradient ascent, with minimal information exchange between nodes.
The algorithm uses time varying weights to give priority to flows. The
performance of the algorithm is studied in a network with interference modelled
by independent sets
Hop-Based dynamic fair scheduler for wireless Ad-Hoc networks
In a typical multihop Ad-Hoc network, interference and contention increase when flows transit each node towards destination, particularly in the presence of cross-traffic. This paper observes the relationship between throughput and path length, self-contention and interference and it investigates the effect of multiple data rates over multiple data flows in the network. Drawing from the limitations of the 802.11 specification, the paper proposes a scheduler named Hop Based Multi Queue (HBMQ), which is designed to prioritise traffic based on the hop count of packets in order to provide fairness across different data flows. The simulation results demonstrate that HBMQ performs better than a Single Drop Tail Queue (SDTQ) scheduler in terms of providing fairness. Finally, the paper concludes with a number of possible directions for further research, focusing on cross-layer implementation to ensure the fairness is also provided at the MAC layer. © 2013 IEEE
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