TCP Streaming Research Articles

A New Design for Live Neutron Event Data Visualisation for ISIS and the ESS

Viewing and reducing event data live during an experiment is an important component of contemporary experiment control systems. At ISIS a simple TCP streaming mechanism for neutron event data allows data to be processed by Mantid during an experiment; however, this existing solution is likely to encounter performance issues with the new generation of acquisition hardware. As part of an ESS in-kind collaboration, ISIS is working on developing a new data streaming system based on Apache Kafka for managing and delivering live experiment data to multiple clients. This work provides an ideal opportunity to replace the existing ISIS streaming mechanism with this new system, which not only provides enhanced functionality for ISIS but also functions as a prototype for developing and testing requirements of the ESS.

지그비 통신망을 이용한 보안등 관제 시스템에 관한 연구

Abstract: This paper relates to the study about the street security light management system. The purpose of the wireless remote management system is to manage street security lights efficiently. The system is composed of three components like light controller, CDMA gateway and web based remote management server. The zig-bee solution is adopted to make local wireless network between street security lights. The CDMA network is used for the wireless communication between street security light controller and the remote control center. The gateway to interconnect zigbee network and CDMA was designed with low power 32 bits Cortex M3 mi-cro-controller. For the data communication between the management server and the gateway, SMS and socket based TCP streaming is used. The management server sends SMS to the gateway to deliver light control and management requests, and the gateway replies with the light controllers report via TCP streaming. By using both SMS and TCP streaming communication, it was verified that simple cost effective management is possible for street security lights. We tried real test for 95 street security lights in real environment during two months and ana-lyzed the practical possibility for mass supply.

Model and Performance of a No-Reference Quality Assessment Metric for Video Streaming

Video streaming via TCP networks has become a popular and highly demanded service, but its quality assessment in both objective and subjective terms has not been properly addressed. In this paper, based on statistical analysis a full analytic model of a no-reference objective metric, namely Pause Intensity, for video quality assessment is presented. The model characterizes the video playout buffer behavior in connection with the network performance (throughput) and the video playout rate. This allows for instant quality measurement and control without requiring a reference video. Pause intensity specifically addresses the need for assessing the quality issue in terms of the continuity in the playout of TCP streaming videos, which cannot be properly measured by other objective metrics such as PSNR, SSIM and buffer underrun or pause frequency. The performance of the analytical model is rigidly verified by simulation results and subjective tests using a range of video clips. It is demonstrated that pause intensity is closely correlated with viewer opinion scores regardless of the vastly different composition of individual elements, such as pause duration and pause frequency which jointly constitute this new quality metric. It is also shown that the correlation performance of pause intensity is consistent and content independent.

Analytical Framework for Improving the Quality of Streaming Over TCP

Multimedia streaming applications are traditionally delivered over UDP. Recent measurements show that more and more multimedia streaming data are over TCP as web-based TV, P2P streaming, video sharing websites are getting increasingly popular. To improve the quality of experience (QoE) for users and to cope with variability in TCP throughput, streaming applications typically implement buffers. Yet, for improving the QoE and the streaming quality, e.g., playback continuity and timeliness, it is critical to dimension buffers and the initial buffering delay appropriately. In this paper, we first develop a model for TCP streaming systems and an analytical framework to assess the QoE. Our emphasis is on buffer occupancy, which depends on the TCP arriving rate and the playout rate (the coding rate). We observe that TCP window “bounds”, namely congestion window sizes immediately before a triple duplicate or timeout event, allow to distinguish the minimum and maximum buffer occupancy for TCP streaming systems. As confirmed by experiments, the proposed analytical framework allows to estimate the frequency of buffer overflow or underflow events if buffer sizes and the initial buffering delays are known parameters, or conversely, to dimension the buffer and delay appropriately. We further extend our model and analysis for P2P multicast streaming systems. Simulations and experiments in real networks validate our proposed analytical framework in terms of underflow/overflow probabilities and delay.

Enhancing the performance of TCP over Wi-Fi power saving mechanisms

The Wi-Fi technology is quickly being adopted by new types of devices that pose stringent requirements in terms of energy efficiency. In order to address these requirements the IEEE 802.11 group developed in the recent years several power saving protocols, that are today widely used among devices like smartphones. In this paper we study, by means of analysis and simulation, the effect that these power saving protocols have on the performance/energy trade-off experienced by long lived TCP traffic. Our study unveils that the efficiency of Wi-Fi power saving protocols critically depends on the bottleneck bandwidth experienced by a TCP connection. Based on the obtained insights, we design and evaluate a novel algorithm, BA-TA, which runs in a Wi-Fi station, does not require any modification to existing 802.11 standards, and using only information available at layer two, improves the performance/energy trade off of long lived TCP connections, whilst also exhibiting a notable performance with Web traffic and TCP Streaming.

A New Buffer Management Mechanism for QoS-Aware IP Router

In this paper, in order to guarantee more sophisticated QoS for TCP streaming, we expand the function of output buffer control mechanism in QoS-aware IP router. Specifically, we proposed the mechanism which calculates transmission band-width and buffer volume preferentially available according to flow condition only in the QoS-aware router by measuring transmitted packets per flow. Furthermore, through computer simulation, the effectiveness of our proposal is verified.

Multimedia streaming via TCP

TCP is widely used in commercial multimedia streaming systems, with recent measurement studies indicating that a significant fraction of Internet streaming media is currently delivered over HTTP/TCP. These observations motivate us to develop analytic performance models to systematically investigate the performance of TCP for both live and stored-media streaming. We validate our models via ns simulations and experiments conducted over the Internet. Our models provide guidelines indicating the circumstances under which TCP streaming leads to satisfactory performance, showing, for example, that TCP generally provides good streaming performance when the achievable TCP throughput is roughly twice the media bitrate, with only a few seconds of startup delay.