Explicit rate control for MANET

Streaming applications over Mobile Ad-hoc Networks (MANET) require a smooth transmission rate. The Internet is unable to provide this service during traffic congestion in the network. Designing congestion control for these applications is challenging, because the standard TCP congestion control mechanism is not able to handle the special properties of a shared wireless multi hop channel well. In particular, the frequent changes to the network topology and the shared nature of the wireless channel pose major challenges. In this paper, we propose a novel approach, which allows a quick increase of throughput by using explicit feedback from routers

A Survey on Issues and Challenges in Congestion Adaptive Routing in Mobile Ad hoc Network

Mobile ad hoc networks is the future wireless communication systems have recently emerged as an important trend. Mobile adhoc network is self-configurable and adaptive. Due to the mobility of nodes, the network congestion occurs and it is difficult to predict load on the network which leads to congestion. Mobile adhoc network suffers from a severe congestion controlling problem due to the nature of shared communication and mobility. Standard TCP controlling mechanism for congestion is not fit to the dynamic changing topology of MANETs. This provides a wide scope of research work in mobile ad hoc network. The purpose of this survey is to study and analyze various issues and challenges in congestion control mechanisms in adaptive routing protocols in Mobile Adhoc Network (MANET)

UTFRC - Utility-driven TCP-Friendly Rate Control for Multimedia Streams

This paper describes UTFRC- Utility-driven TCP-Friendly Rate Control, a congestion control mechanism more suitable for streaming layered scalable video streams in best-effort networks than TFRC [2]. UTFRC relies on the original TFRC for achieving a stable throughput, but uses the throughput outputted by TFRC only as a guideline and shapes this throughput, on a coarser granularity scale, according to media characteristics of the video stream. This way, UTFRC is TCP-friendly when computing avail-able bandwidth, but it is also media-sensitive (i.e., media-friendly). We present two versions of UTFRC, a simple one based only on bitrate properties of the video stream and an advanced one which takes into account also the client prefetching buffer value, but other media characteristics of the stream can also be considered. UTFRC improves the perceived quality of video streams in best-effort network conditions. 1

On the Long-Run Behavior of Equation-Based Rate Control

We consider unicast equation based rate control, where a source estimates the loss event ratio p, and, primarily at loss events, adjusts its sending rate to f(p). Function f is assumed to represent the loss-throughput relation that TCP would experience. When no loss occurs, the rate may also be increased according to some additional mechanism. We assume that the loss event interval estimator is non-biased. If the loss process is deterministic, the control is TCP-friendly in the long run, i.e, the average throughput does not exceed that of TCP. If, in contrast, losses are random, it is not a priori clear whether this holds, due to the non-linearity of f, and a phenomenon similar to Feller`s paradox. Our goal is to identify the key factors that drive whether, and how far, the control is TCP friendly (in the long run). As TCP and our source may experience different loss event intervals, we distinguish between TCP-friendly and conservative (throughput does not exceed f(p)). We give a representation of the long term throughput, and derive that conservativeness is primarily influenced by various convexity properties of f, the variability of loss events, and the correlation structure of the loss process. In many cases, these factors lead to conservativeness, but we show reasonable lab experiments where the control is clearly non-conservative. However, our analysis also suggests that our source should experience a higher loss event ratio than TCP, which would make non-TCP friendliness less likely. Our findings provide guidelines that help understand when an equation base control is indeed TCP-friendly in the long run, and in some cases, excessively so. The effect of round trip time and its variation is not included in this study

REFWA: An Efficient and Fair Congestion Control Scheme for LEO Satellite Networks

科研費報告書収録論文(課題番号:17500030/研究代表者:加藤寧/インターネットと高親和性を有する次世代低軌道衛星ネットワークに関する基盤研究

Qos In Cognitive Packet Networks: Adaptive Routing, Flow And Congestion Control

With the emergence of various applications that have different Quality of Service (QoS) requirements, the capability of a network to support QoS becomes more and more important and necessary. This dissertation explores QoS in Cognitive Packet Networks (CPN) by using adaptive routing, flow and congestion control. We present a detailed description and analysis of our proposed routing algorithms based on single and multiple QoS constraints. An online estimation of packet loss rate over a path is introduced. We implement and evaluate the adaptive routing scheme in an experimental CPN test-bed. Our experiments support our claims that the users can achieve their desired best-effort QoS through this routing scheme. We also propose a QoS-based flow and congestion control scheme that is built in the transport layer and specially designed to work with CPN to support users\u27 QoS while remaining friendly to TCP. Theoretical models and experimental analysis are presented. Finally we experimentally demonstrate that the proposed flow and congestion control scheme can effectively control the input flows, react to the congestion and work with our proposed adaptive routing scheme to achieve users\u27 QoS