Experimental Evaluation of TCP-Based DTN for Cislunar Communications in Presence of Long Link Disruption

Ruhai Wang,Xuan Wu,Zhensheng Zhang,Tarik Taleb,Qinyu Zhang,Jia Hou

doi:10.1155/2011/720671

Abstract

Delay/disruption tolerant networking (DTN) technology is considered a new solution to highly stressed communications in space environments. To date, little work has been done in evaluating the effectiveness and performance of the available DTN protocols when they are applied to an interplanetary Internet, especially in presence of a long link disruption. In this paper, we present an experimental investigation of the DTN architecture with a Bundle Protocol (BP) running over TCP-based convergence layer (TCPCL) protocol in a simulated cislunar communication environment characterized by a long link disruption. The intent of this work is to investigate the effectiveness of the TCPCL-based DTN protocol in coping with long link disruptions, through realistic file transfer experiments using a PC-based test-bed. The experiment results show that the DTN protocol is effective in handling a long link disruption experienced in data transmission accompanied by a cislunar link delay and a high BER. The performance of the DTN is most adversely affected by link disruption time in comparison to the effect of link delay and BER. For the transmissions with a very long link disruption of hours, the variations in goodput are nominal with respect to the change in cislunar link delay.

Highlights

Several issues of the space internetworking are inappropriately addressed by TCP [1], limiting its performance in space communications, especially in deep space [2,3,4]
We present an experimental investigation of the disruption tolerant networking (DTN) architecture with a Bundle Protocol (BP) running over TCP-based convergence layer (TCPCL) protocol in a simulated cislunar communication environment characterized by a long link disruption
We present an experimental investigation of the DTN architecture with a BP running over TCPCL protocol in an emulated cislunar communication environment characterized by a long link disruption

Summary

Introduction

Several issues of the space internetworking are inappropriately addressed by TCP [1], limiting its performance in space communications, especially in deep space [2,3,4]. With the sliding window flow-control mechanisms, TCP regulates the amount of data a source can send by adjusting the window size in response to the acknowledgement information from the destination; the timeliness of that information is key to the effectiveness of the technique. Another major issue is that TCP cannot distinguish between data losses caused by network congestion and link errors. Many alternative transmission control protocols have been developed for space communications [4,5,6,7,8,9,10,11,12,13,14,15,16].

Methods

Results

Conclusion