6,271 research outputs found
Active Queue Management for Fair Resource Allocation in Wireless Networks
This paper investigates the interaction between end-to-end flow control and MAC-layer scheduling on wireless links. We consider a wireless network with multiple users receiving information from a common access point; each user suffers fading, and a scheduler allocates the channel based on channel quality,but subject to fairness and latency considerations. We show that the fairness property of the scheduler is compromised by the transport layer flow control of TCP New Reno. We provide a receiver-side control algorithm, CLAMP, that remedies this situation. CLAMP works at a receiver to control a TCP sender by setting the TCP receiver's advertised window limit, and this allows the scheduler to allocate bandwidth fairly between the users
Cross-layer scheduling and resource allocation for heterogeneous traffic in 3G LTE
3G long term evolution (LTE) introduces stringent needs in order to provide different kinds of traffic with Quality of Service (QoS) characteristics. The major problem with this nature of LTE is that it does not have any paradigm scheduling algorithm that will ideally control the assignment of resources which in turn will improve the user satisfaction. This has become an open subject and different scheduling algorithms have been proposed which are quite challenging and complex. To address this issue, in this paper, we investigate how our proposed algorithm improves the user satisfaction for heterogeneous traffic, that is, best-effort traffic such as file transfer protocol (FTP) and real-time traffic such as voice over internet protocol (VoIP). Our proposed algorithm is formulated using the cross-layer technique. The goal of our proposed algorithm is to maximize the expected total user satisfaction (total-utility) under different constraints. We compared our proposed algorithm with proportional fair (PF), exponential proportional fair (EXP-PF), and U-delay. Using simulations, our proposed algorithm improved the performance of real-time traffic based on throughput, VoIP delay, and VoIP packet loss ratio metrics while PF improved the performance of best-effort traffic based on FTP traffic received, FTP packet loss ratio, and FTP throughput metrics
Confucius Queue Management: Be Fair But Not Too Fast
When many users and unique applications share a congested edge link (e.g., a
home network), everyone wants their own application to continue to perform well
despite contention over network resources. Traditionally, network engineers
have focused on fairness as the key objective to ensure that competing
applications are equitably and led by the switch, and hence have deployed fair
queueing mechanisms. However, for many network workloads today, strict fairness
is directly at odds with equitable application performance. Real-time streaming
applications, such as videoconferencing, suffer the most when network
performance is volatile (with delay spikes or sudden and dramatic drops in
throughput). Unfortunately, "fair" queueing mechanisms lead to extremely
volatile network behavior in the presence of bursty and multi-flow applications
such as Web traffic. When a sudden burst of new data arrives, fair queueing
algorithms rapidly shift resources away from incumbent flows, leading to severe
stalls in real-time applications. In this paper, we present Confucius, the
first practical queue management scheme to effectively balance fairness against
volatility, providing performance outcomes that benefit all applications
sharing the contended link. Confucius outperforms realistic queueing schemes by
protecting the real-time streaming flows from stalls in competing with more
than 95% of websites. Importantly, Confucius does not assume the collaboration
of end-hosts, nor does it require manual parameter tuning to achieve good
performance
Optimizing Service Differentiation Scheme with Sized-based Queue Management in DiffServ Networks
In this paper we introduced Modified Sized-based Queue Management as a
dropping scheme that aims to fairly prioritize and allocate more service to
VoIP traffic over bulk data like FTP as the former one usually has small packet
size with less impact to the network congestion. In the same time, we want to
guarantee that this prioritization is fair enough for both traffic types. On
the other hand we study the total link delay over the congestive link with the
attempt to alleviate this congestion as much as possible at the by function of
early congestion notification. Our M-SQM scheme has been evaluated with NS2
experiments to measure the packets received from both and total link-delay for
different traffic. The performance evaluation results of M-SQM have been
validated and graphically compared with the performance of other three legacy
AQMs (RED, RIO, and PI). It is depicted that our M-SQM outperformed these AQMs
in providing QoS level of service differentiation.Comment: 10 pages, 9 figures, 1 table, Submitted to Journal of
Telecommunication
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