TCP Network Coding with Enhanced Retransmission for Heavy and Bursty Loss

In general, Transmission Control Protocol (TCP), e.g., TCP NewReno, considers all losses to be a sign of congestion. It decreases the sending rate whenever a loss is detected. Integrating the network coding (NC) into protocol stack and making it cooperate with TCP (TCP/NC) would provide the benefit of masking packet losses in lossy networks, e.g., wireless networks. TCP/NC complements the packet loss recovery capability without retransmission at a sink by sending the redundant combination packets which are encoded at the source. However, TCP/NC is less effective under heavy and bursty loss which often occurs in fast fading channel because the retransmission mechanism of the TCP/NC entirely relies on the TCP layer. Our solution is TCP/NC with enhanced retransmission (TCP/NCwER), for which a new retransmission mechanism is developed to retransmit more than one lost packet quickly and efficiently, to allow encoding the retransmitted packets for reducing the repeated losses, and to handle the dependent combination packets for avoiding the decoding failure. We implement and test our proposal in Network Simulator 3. The results show that TCP/NCwER overcomes the deficiencies of the original TCP/NC and improves the TCP goodput under both random loss and burst loss channels

TCP network coding with adapting parameters for bursty and time-varying loss

The Transmission Control Protocol (TCP) with Network Coding (TCP/NC) was proposed to introduce packet loss recovery ability at the sink without TCP retransmission, which is realized by proactively sending redundant combination packets encoded at the source. Although TCP/NC is expected to mitigate the goodput degradation of TCP over lossy networks, the original TCP/NC does not work well in burst loss and time-varying channels. No apparent scheme was provided to decide and change the network coding-related parameters (NC parameters) to suit the diverse and changeable loss conditions. In this paper, a solution to support TCP/NC in adapting to mentioned conditions is proposed, called TCP/NC with Loss Rate and Loss Burstiness Estimation (TCP/NCwLRLBE). Both the packet loss rate and burstiness are estimated by observing transmitted packets to adapt to burst loss channels. Appropriate NC parameters are calculated from the estimated probability of successful recoverable transmission based on a mathematical model of packet losses. Moreover, a new mechanism for coding window handling is developed to update NC parameters in the coding system promptly. The proposed scheme is implemented and validated in Network Simulator 3 with two different types of burst loss model. The results suggest the potential of TCP/NCwLRLBE to mitigate the TCP goodput degradation in both the random loss and burst loss channels with the time-varying conditions

TCP with Network Coding Performance Under Packet Reordering

The adverse impact of packet reordering besides packet loss is significant on the goodput performance of TCP (Transmission Control Protocol), a dominant protocol for reliable and connection-oriented transmission. With the primary purpose of improving the TCP goodput in lossy networks, the Network Coding technique was introduced. TCP/NC (TCP with Network Coding) is a promising approach which can recover lost packets without retransmission. However, the packet reordering has not been considered, and no study on that issue is found for TCP/NC. Therefore, in this paper, we investigate the goodput performance degradation due to the out-of-order reception of data or acknowledgment packets and propose a new scheme for TCP/NC to estimate and adapt to the packet reordering. The results of our simulation on ns-3 (Network Simulation 3) suggest that the proposed scheme can maintain the TCP goodput well in a wide range of packet reordering environments compared to TCP NewReno as well as TCP/NC.International Conference on Emerging Internetworking, Data & Web Technologies (EIDWT 2019), 26-28 February, 2019, Fujairah Campus, United Arab Emirate

Masking Lossy Networks by TCP Tunnel with Network Coding

Transmission Control Protocol (TCP) with Network Coding (TCP/NC) was designed to recover the lost packets without TCP retransmission to improve the goodput performance in lossy networks. However, TCP/NC is too costly to be implemented in some types of end devices, e.g., with less memory and power. In addition, TCP/NC across loss-free but thin networks may waste scarce link bandwidth due to the redundant combination packets sacrificed for the lossy network. In this paper, we propose the TCP/NC tunnel to convey end-to-end TCP sessions on a single TCP/NC flow traversing a lossy network between two special gateways without per-flow management. We implemented and validated our proposal in Network Simulator 3, in which each gateway runs a reinforced version of TCP/NC that we previously developed. The results show that the proposed TCP/NC tunnel can mitigate the goodput degradation of end-to-end TCP sessions traversing a lossy network without any change in TCP on each end host.The 22nd IEEE Symposium on Computers and Communications (ISCC\u2717), 03 - 06 July 2017, Heraklion, Crete, Greec

TCP/NC performance in bi-directional loss environments

Transmission Control Protocol with Network Coding (TCP/NC) is studied to improve the goodput performance of the standard TCP in lossy networks (e.g., wireless networks). TCP/NC uses additional sub-layer called Network Coding layer below TCP layer to handle packet losses without sensed by TCP layer. Basically, n+k combination packets combined from n original packets are sent by the source. When the sink receives enough n combination packets, the sink can calculate n original packet even though k \u27 packets are lost where k \u27 is less than or equal to k. Most versions of TCP/NC consider the loss in only the direction of sending data; however, the loss in the reverse direction, i.e., the direction of sending an acknowledgment, affects seriously to goodput performance, especially in TCP/NC with an automatic estimation of Network Coding parameters n and k) case. In this paper, we propose a new scheme for the bi-directional loss issue. The result of our simulation on ns-3 (Network Simulation 3) shows that the proposed scheme can work well when loss happens in both directions compared to the TCP NewReno and our previously proposed, TCP/NC with Loss Rate and Loss Burstiness Estimation (TCP/NCwLRLBE).18th International Conference on Electronics, Information, and Communication (ICEIC 2019), January 22 - 25, 2019, Pullman Auckland Hotel, New Zealan

Tolerance of TCP with network coding to reverse-direction packet loss and packet reordering

Transmission Control Protocol with Network Coding (TCP/NC) is one of the potential proposals for improving the goodput performance of the current TCP protocol in lossy networks (e.g., wireless networks). TCP/NC uses additional sub-layer called Network Coding layer below TCP layer to handle packet losses without sensed by TCP layer. The authors introduced some variants of TCP/NC such as TCP/NCwLRLBE (TCP/NC with Loss Rate and Loss Burstiness Estimation) which can improve the retransmission and adapt to the changing of the channel. However, most versions of TCP/NC do not consider two problems, that are the bi-directional packet loss and the unordering packet receiving, which affect the goodput performance seriously. Therefore, in this paper, we investigate the goodput performance degradation by the bi-directional packet loss and the unordering packet receiving, and propose solutions. The result of our simulation on ns-3 (Network Simulation 3) shows that the proposed scheme can work well when loss happens in both directions as well as in unordering packet receiving environment compared to the TCP NewReno and our previously proposed protocol, TCP/NCwLRLBE.電子情報通信学会 情報ネットワーク研究会（IN）, 2018年12月13日-14日, 広島大学, 日

Evaluation of a Set of TCP Features over Narrowband Radio Bearer for Train Communication

An engineering approach to the evaluation of the TCP as a narrowband bearer for short messages in the low latency train-trackside communication scenario is described in this report. The project was developed in cooperation with Bombardier Transportation Sweden AB as a part of the “ETCS over GPRS” venture. With the increase of the demands from the railway industry, the currently used circuit-switched GSM-R technology becomes unsatisfactory from the radio system capacity point of view and the need of a new solution is highly required. The packet-switched GPRS solution using TCP as a suite is under research for this specific scenario. The investigated problem in this report concerns the tuning of the retransmission mechanism, which includes the TCP features TCP_RTO_MIN and TCP_KEEPALIVE. This implies the tuning of those features to be able to detect a loss of communication and to react less aggressively for the short and instantaneous changes in the network delay. This thesis work began with a preparation phase in which a broad literature analysis of the background theory was made and followed by the development of applications that realizes the traffic model. Later in the performance phase the required changes were applied on the system and finally tested in a lab. The tests have been performed using one and four pairs of client-server applications communicating over an emulated link. The TCP features were modified at two levels, the TCP_RTO_MIN by a kernel recompilation and the TCP_KEEPALIVE by changes on the live system. Results from the tests have shown that for the higher than the default value of the TCP_RTO_MIN the less retransmissions were triggered. The TCP_KEEPALIVE has proven to be a sufficient feature to indicate a loss of the link. However the achieved improvement in performance was not as high as expected, but acceptable for this scenario. The train-trackside communication system could benefit from the proposed changes

Optimization and Performance Analysis of High Speed Mobile Access Networks

The end-to-end performance evaluation of high speed broadband mobile access networks is the main focus of this work. Novel transport network adaptive flow control and enhanced congestion control algorithms are proposed, implemented, tested and validated using a comprehensive High speed packet Access (HSPA) system simulator. The simulation analysis confirms that the aforementioned algorithms are able to provide reliable and guaranteed services for both network operators and end users cost-effectively. Further, two novel analytical models one for congestion control and the other for the combined flow control and congestion control which are based on Markov chains are designed and developed to perform the aforementioned analysis efficiently compared to time consuming detailed system simulations. In addition, the effects of the Long Term Evolution (LTE) transport network (S1and X2 interfaces) on the end user performance are investigated and analysed by introducing a novel comprehensive MAC scheduling scheme and a novel transport service differentiation model