Showing papers by "Ruhai Wang published in 2009"
TL;DR: A survey on the protocols proposed for reliable data transport in space Internet, with a focus on the latest developments, is presented, classification of these protocols into different approaches.
Abstract: A variety of protocols have been proposed for reliable data transport in space Internet and similar network environments. It is necessary to conduct a survey on these protocols to investigate and compare among them. In this article, we present a survey on the protocols proposed for reliable data transport in space Internet, with a focus on the latest developments. The survey includes the following contents: (1) classification of these protocols into different approaches; (2) discussions and comments on the design and operation methods of the protocols; and (3) comparisons and comments on the main techniques and performance of the protocols.
71 citations
TL;DR: It is concluded that SCPS-TP is better suited than TCP over long-delayed, asymmetric, satellite channels with a throughput advantage of over 30 Kbyte/s for the transmission of a 10 Mbyte file.
Abstract: As the transport layer protocol of the Space Communication Protocol Standard (SCPS) suite, SCPS-Transport Protocol (SCPS-TP) is actually transmission control protocol (TCP), with a set of extensions aimed at improving TCP performance in space communications. Some work has been done on the performance evaluation of SCPS-TP in comparison with TCP. However, those works have been done by testing SCPS-TP via emulation test-beds. We present the file transfer experimental work of testing the SCPS protocol stack over NASA's geostationary orbit (GEO) Advanced Communications Technology Satellite (ACTS). Considering that space communication channels in practice are frequently asymmetric in terms of channel bandwidth, our work is concentrated on the evaluation of the effectiveness of SCPS-TP in coping with channel rate asymmetry. We conclude that SCPS-TP is better suited than TCP over long-delayed, asymmetric, satellite channels with a throughput advantage of over 30 Kbyte/s for the transmission of a 10 Mbyte file. A hybrid of the channel rate control and acknowledgment frequency reduction mechanisms makes significant contributions to the performance enhancement of SCPS-TP over asymmetric space channels.
15 citations
30 Nov 2009
TL;DR: An experimental evaluation of the DTN protocols with BP/TCPCL running on top of TCP/IP over a long-delay cislunar communication channel with and without link disruption is presented.
Abstract: TCP experiences severe performance degradation in cislunar communications because of some assumptions built into its design. Delay/disruption tolerant networking (DTN) is a class of network techniques that is developed to work over internet protocols to accommodate long link delay and frequent link disruptions in space communication environment. Most of the work concerning DTN protocols and techniques focused on its application in terrestrial wireless network and sensor-based networks. In this paper, we present an experimental evaluation of the DTN protocols with BP/TCPCL running on top of TCP/IP over a long-delay cislunar communication channel with and without link disruption. We hope the experiment results and analysis in this paper will apply equally well in any deep space mission with a round-trip time (RTT) that is comparable to that of the Earth-Moon system.
9 citations
30 Nov 2009
TL;DR: An experimental investigation of the BP/LTP protocol, running on top of an unreliable UDP stack, over a cislunar link with long propagation delays, frequent disconnects, and a high bit error rate (BER).
Abstract: With demands increasing in lunar and Mars explorations, the need for a new space communication standard protocol is becoming more and more critical. The DTN Research Group (DTNRG) is developing a series of communication protocols with new architecture, generally called DTN protocols, to tolerate highly stressed communication environments with long propagation delays and frequent link disruptions. In this paper, we present an experimental investigation of the bundle protocol (BP), over Licklider transmission protocol (LTP - sometimes called the long-haul transmission protocol), operating with unreliable User Datagram Protocol (UDP), over an emulated cislunar networking under various channel conditions. Our intention is to investigate the transmission performance of the BP/LTP protocol, running on top of an unreliable UDP stack, over a cislunar link with long propagation delays, frequent disconnects, and a high bit error rate (BER). A comparison between BP/LTP/UDP and another DTN protocol suite is also presented.
7 citations