Download or read book Improving TCP Performance Over Wireless Networks at the Link Layer written by Christina Parsa and published by . This book was released on 1998 with total page 140 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Improving TCP Performance Over Wireless Networks written by Abhijit Vijay Warkhedi and published by . This book was released on 2000 with total page 338 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book TCP Performance over UMTS HSDPA Systems written by Mohamad Assaad and published by CRC Press. This book was released on 2006-07-20 with total page 232 pages. Available in PDF, EPUB and Kindle. Book excerpt: The evolution of the mobile communication market is causing a major increase in data traffic demands. This could lead to disrupted mobility and intermittent degraded channel conditions that contribute to poor transmission control protocol (TCP) performance. TCP Performance over UMTS-HSDPA Systems presents a comprehensive study of the effect of TCP

Download or read book Improving TCP IP Performance Over Wireless Networks written by Hari Balakrishnan and published by . This book was released on 1995 with total page 40 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Effect of Slow Fading and Adaptive Modulation on TCP UDP Performance of High speed Packet Wireless Networks written by Xuanming Dong and published by . This book was released on 2006 with total page 290 pages. Available in PDF, EPUB and Kindle. Book excerpt: High speed data wireless networks in multipath environments suffer channel impairment from many sources such as thermal noise, path loss, shadowing, and fading. In particular, short-term fading caused by mobility imposes irreducible error floor bounds on system performance. We study the effect of fading on the performance of the widely used TCP/UDP protocol, and investigate how to improve TCP performance over fading channels. Our solutions target upcoming mobile wireless systems such as IEEE 802.16e wireless MANs "Metropolitan Area Networks" where adaptive modulation is enabled and the underlying medium access scheme is On-Demand Time Division Multiple Access "On-Demand TDMA". Adaptive modulation is used in the new generation of wireless systems to increase the system throughput and significantly improve spectral effciency by matching parameters of the physical layer to the time-varying fading channels. Most high-rate applications for such wireless systems rely on the reliable service provided by TCP protocol. The effect of adaptive modulation on TCP throughput is investigated. A semi-Markov chain model for TCP congestion/flow control behavior and a multi-state Markov chain model for Rayleigh fading channels are used together to derive the steady state throughput of TCP Tahoe and Reno. The theoretical prediction based on our analysis is consistent with simulation results using the network simulator NS2. The analytical and simulation results triggered the idea of cross-layer TCP protocol design for single-user scenarios. The fading parameters of wireless channels detected in the physical layer can be used to dynamically tune the parameters "such as packet length and advertised receiver window size" of the TCP protocol in the transport layer so that TCP throughput is improved. For multi-user scenarios, we study how multi-user diversity can be used to improve th.

Download or read book Improvement of TCP Performance in Wireless Networks written by Wan Gang Zeng and published by . This book was released on 2006 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Transmission Control Protocol (TCP) was designed and optimized to work well over wired networks. It suffers significant performance degradation in wireless networks due to their different characteristics, such as high Bit-Error Rate (BER), large and variable delay and bursty traffic. In this thesis, I propose packet control algorithms to be deployed in intermediate network routers. They improve TCP performance in wireless networks with packet delay variations and long sudden packet delays. The ns-2 simulation results show that the proposed algorithms reduce the adverse effect of spurious fast retransmits and timeouts and greatly improve the goodput compared to the performance of TCP Reno. The TCP goodput was improved by 3̃0% in wireless networks with 1% packet loss. TCP performance was also improved in cases of long sudden delays. These improvements highly depend on the wireless link characteristics.

Download or read book Intelligent Wireless Management written by Tiki L. Suarez and published by . This book was released on 2001 with total page 1280 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Improving TCP Performance Over Heterogeneous Networks written by M. A. Alnuem and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Transmission Control Protocol (TCP) is considered one of the most important protocolsin the Internet. An important mechanism in TCP is the congestion controlmechanism which controls TCP sending rate and makes TCP react to congestionsignals. Nowadays in heterogeneous networks, TCP may work in networks with somelinks that have lossy nature (wireless networks for example). TCP treats all packetloss as if they were due to congestion. Consequently, when used in networks thathave lossy links, TCP reduces sending rate aggressively when there are transmission(non-congestion) errors in an uncongested network. One solution to the problem is to discriminate between errors; to deal with congestionerrors by reducing TCP sending rate and use other actions for transmissionerrors. In this work we investigate the problem and propose a solution using anend-to-end error discriminator. The error discriminator will improve the currentcongestion window mechanism in TCP and decide when to cut and how much tocut the congestion window. We have identified three areas where TCP interacts with drops: congestion windowupdate mechanism, retransmission mechanism and timeout mechanism. All ofthese mechanisms are part of the TCP congestion control mechanism. We proposechanges to each of these mechanisms in order to allow TCP to cope with transmissionerrors. We propose a new TCP congestion window action (CWA) for transmissionerrors by delaying the window cut decision until TCP receives all duplicate acknowledgmentsfor a given window of data (packets in flight). This will give TCP a clearimage about the number of drops from this window. The congestion window size isthen reduced only by number of dropped packets. Also, we propose a safety mechanismto prevent this algorithm from causing congestion to the network by usingan extra congestion window threshold (tthresh) in order to save the safe area wherethere are no drops of any kind. The second algorithm is a new retransmission actionto deal with multiple drops from the same window. This multiple drops action(MDA) will prevent TCP from falling into consecutive timeout events by resendingall dropped packets from the same window. A third algorithm is used to calculatea new back-off policy for TCP retransmission timeout based on the network?s availablebandwidth. This new retransmission timeout action (RTA) helps relating thelength of the timeout event with current network conditions, especially with heavytransmission error rates. The three algorithms have been combined and incorporated into a delay basederror discriminator. The improvement of the new algorithm is measured along withthe impact on the network in terms of congestion drop rate, end-to-end delay, averagequeue size and fairness of sharing the bottleneck bandwidth. The results show thatthe proposed error discriminator along with the new actions toward transmissionerrors has increased the performance of TCP. At the same time it has reduced theload on the network compared to existing error discriminators. Also, the proposederror discriminator has managed to deliver excellent fairness values for sharing thebottleneck bandwidth. Finally improvements to the basic error discriminator have been proposed byusing the multiple drops action (MDA) for both transmission and congestion errors. The results showed improvements in the performance as well as decreases in thecongestion loss rates when compared to a similar error discriminator.

Download or read book The Design and Implementation of the 4 3BSD UNIX Operating System written by Samuel J. Leffler and published by . This book was released on 1989 with total page 498 pages. Available in PDF, EPUB and Kindle. Book excerpt: The first authoritative description of Berkeley UNIX, its design and implementation. Book covers the internal structure of the 4.3 BSD systems and the concepts, data structures and algorithms used in implementing the system facilities. Chapter on TCP/IP. Annotation copyright Book News, Inc. Portlan.

Download or read book Reducing Handover Latency and Improving TCP Performance in Wireless Networks written by Beizhong Chen and published by . This book was released on 2010 with total page 125 pages. Available in PDF, EPUB and Kindle. Book excerpt: Modern network technologies first evolved in wired networks and subsequently entered the wireless network field. Applications may work in pure wired network, pure wireless network or hybrid network. Improving performance in these network infrastructures has been a continuous effort for decades. In this dissertation, we tackle two important challenges: (1) improving handover performance in heterogeneous wireless network, and (2) improving TCP performance in multi-hop wireless network. In heterogeneous network, users expect uninterrupted services moving from one network to another. IEEE proposed Media Independent Handover (MIH) to make it possible to achieve better handover performance. Currently, Mobile IPv4 (MIP) is the dominant mechanism for mobility management and is expected to persist into the future. However, when multiple interfaces of a mobile client are connected to a Foreign Agent (FA), MIP and its existing improvements do not perform well when the active interface fails unexpectedly. In this dissertation, we propose novel mechanism and MIP extension with MIH support. We prove experimentally that the new approach eliminates the FA-HA latency and achieves much faster handover, compared with existing mechanism. Our method also allows FA-bicasting, which can improve transmission reliability by combining traffic from different links, through the same FA. In multi-hop wireless networks, the main network factor that affects TCP performance is the medium-access contention, complicated by other factors like hidden terminal. We analyze the TCP congestion window and provide a more accurate estimate of its optimal value than those reported in the prior work. We also show that the much shorter TCP-ACK packets consume comparable channel capacity as the much longer data packets. We therefore propose two methods to improve TCP throughput, as follows. (1) Segregate the flows of data and ACK using static routing in grid wireless network, (2) Develop an improved variant of delayed TCP ACK by minimizing the number of ACK packets. Our evaluation validates the effectiveness of the proposed method, which can enhance TCP performance significantly. In terms of throughput, it achieves up to 204% improvement over the regular TCP in chain-topology wireless networks, and about 35% improvement in a complex grid wireless network. We also propose a new architecture to achieve higher throughput when multiple TCP connections exist.

Download or read book High Performance Browser Networking written by Ilya Grigorik and published by "O'Reilly Media, Inc.". This book was released on 2013-09-11 with total page 420 pages. Available in PDF, EPUB and Kindle. Book excerpt: How prepared are you to build fast and efficient web applications? This eloquent book provides what every web developer should know about the network, from fundamental limitations that affect performance to major innovations for building even more powerful browser applications—including HTTP 2.0 and XHR improvements, Server-Sent Events (SSE), WebSocket, and WebRTC. Author Ilya Grigorik, a web performance engineer at Google, demonstrates performance optimization best practices for TCP, UDP, and TLS protocols, and explains unique wireless and mobile network optimization requirements. You’ll then dive into performance characteristics of technologies such as HTTP 2.0, client-side network scripting with XHR, real-time streaming with SSE and WebSocket, and P2P communication with WebRTC. Deliver superlative TCP, UDP, and TLS performance Speed up network performance over 3G/4G mobile networks Develop fast and energy-efficient mobile applications Address bottlenecks in HTTP 1.x and other browser protocols Plan for and deliver the best HTTP 2.0 performance Enable efficient real-time streaming in the browser Create efficient peer-to-peer videoconferencing and low-latency applications with real-time WebRTC transports

Download or read book Network Coding at Different Layers in Wireless Networks written by Yang Qin and published by Springer. This book was released on 2016-05-14 with total page 187 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book focuses on how to apply network coding at different layers in wireless networks – including MAC, routing, and TCP – with special focus on cognitive radio networks. It discusses how to select parameters in network coding (e.g., coding field, number of packets involved, redundant information ration) in order to be suitable for the varying wireless environments. The author explores how to deploy network coding in MAC to improve network performance and examine joint network coding with opportunistic routing to improve the successful rate of routing. In regards to TCP and network coding, the author considers transport layer protocol working with network coding to overcome the transmission error rate, particularly with how to use the ACK feedback of TCP to enhance the efficiency of network coding. The book pertains to researchers and postgraduate students, especially whose interests are in opportunistic routing and TCP in cognitive radio networks.

Download or read book Improving TCP Performance by Estimating Errors in a Long Delay High Error Rate Environment written by Stephanie E. Carroll and published by . This book was released on 2004-07-01 with total page 103 pages. Available in PDF, EPUB and Kindle. Book excerpt: Interest in finding methods of improving TCP performance over satellite and wireless networks is high. This has been an active area of research within the networking community. This research develops an algorithm, CETEN-R for TCP to determine if a particular packet is lost due to congestion or corruption and react accordingly. An analysis of the performance of CETEN-R under a variety of conditions is studied and then compared to TCP Reno and TCP New Reno. When delay is high and the error rate is high CETEN-R showed a 77.5% increase in goodput over TCP New Reno and a 33.8% increase in goodput over TCP Reno. When delay is low and the error rate is high, CETEN-R showed a 146% increase in goodput over TCP New Reno and a 77% increase in goodput over TCP reno. At low error rates, CETEN-R provides no advantage over TCP Reno or TCP New Reno.

Download or read book Techniques for End to end TCP Performance Enhancement Over Wireless Networks written by Bong Ho Kim and published by . This book was released on 2016 with total page 262 pages. Available in PDF, EPUB and Kindle. Book excerpt: Today’s wireless network complexity and the new applications from various user devices call for an in-depth understanding of the mutual performance impact of networks and applications. It includes understanding of the application traffic and network layer protocols to enable end-to-end application performance enhancements over wireless networks. Although Transport Control Protocol (TCP) behavior over wireless networks is well known, it remains as one of the main drivers which may significantly impact the user experience through application performance as well as the network resource utilization, since more than 90% of the internet traffic uses TCP in both wireless and wire-line networks. In this dissertation, we employ application traffic measurement and packet analysis over a commercial Long Term Evolution (LTE) network combined with an in-depth LTE protocol simulation to identify three critical problems that may negatively affect the application performance and wireless network resource utilization: (i) impact of the wireless MAC protocol on the TCP throughput performance, (ii) impact of applications on network resource utilization, and (iii) impact of TCP on throughput performance over wireless networks. We further propose four novel mechanisms to improve the end-to-end application and wireless system performance: (i) an enhanced LTE uplink resource allocation mechanism to reduce network delay and help prevent a TCP timeout, (ii) a new TCP snooping mechanism, which according to our experiments, can save about 20% of system resources by preventing unnecessary video packet transmission through the air interface, and (iii) two Split-TCP protocols: an Enhanced Split-TCP (ES-TCP) and an Advanced Split-TCP (AS-TCP), which significantly improve the application throughput without breaking the end-to-end TCP semantics. Experimental results show that the proposed ES-TCP and AS-TCP protocols can boost the TCP throughput by more than 60% in average, when exercised over a 4G LTE network. Furthermore, the TCP throughput performance improvement may be even superior to 200%, depending on network and usage conditions. We expect that these proposed Split-TCP protocol enhancements, together with the new uplink resource allocation enhancement and the new TCP snooping mechanism may provide even greater performance gains when more advanced radio technologies, such as 5G, are deployed. Thanks to their superior resource utilization efficiency, such advanced radio technologies will put to greater use the techniques and protocol enhancements disclosed through this dissertation.

Download or read book Challenges to Reliable Data Transport Over Heterogeneous Wireless Networks written by Hari Balakrishnan and published by . This book was released on 1998 with total page 450 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Improving Performance of TCP Over Wireless Networks written by Miten N. Mehta and published by . This book was released on 1998 with total page 128 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Differential Radio Link Protocol written by Jaideep Sarkar and published by . This book was released on 2005 with total page 77 pages. Available in PDF, EPUB and Kindle. Book excerpt: New generations of wireless cellular networks, including 3G and 4G technologies, are envisaged to support more mobile users and a variety of wireless multimedia services. With an increasing demand for wireless multimedia services, the performance of TCP becomes a bottleneck as it cannot differentiate between the losses due to the nature of air as a medium and high data load on the network that leads to congestion. This misinterpretation by TCP leads to a reduction in the congestion window size thereby resulting in reduced throughput of the system. To overcome this scenario Radio Link Protocols are used at a lower layer which hides from TCP the channel related losses and effectively increases the throughput. This thesis proposes enhancements to the radio link protocol that works underneath TCP by identifying decisive frames and categorizing them as crucial and non-crucial. The fact that initial frames from the same upper layer segment can afford a few trials of retransmissions and the later frames cannot, motivates this work. The frames are treated differentially with respect to FEC coding and ARQ schemes. Specific cases of FEC and ARQ strategies are then considered and it is shown qualitatively as how the differential treatment of frames can improve the performance of the RLP and in effect that of TCP over wireless networks.