BitTorrent is Apt for Geophysical Data Collection and Distribution

This article covers a nouveau idea of how to collect and handle geophysical data with a peer-to-peer network in near real-time. The text covers a brief introduction to the cause, the technology, and the particular case of collecting data from GNSS stations. We describe the proof-of-concept implementation that has been tested. The test was conducted with an experimental GNSS station and a data aggregation facility. In the test, original raw GNSS signal measurements were transferred to the data aggregation center and subsequently to the consumer. Our implementation utilized BitTorrent to communicate and transfer data. The solution could be used to establish the majority of data aggregation centers activities to provide fast, reliable, and transparent real-time data handling experience to the scientific community.Comment: 13 pages, 2 figure

Conceptual Design of an IP-based Satellite Bus using Internet Technologies

The goal of this paper is to develop a generic, reconfigurable spacecraft bus architecture that implements IP-based protocols and networking hardware that is common to terrestrial networks. First, a description of the communications architecture for an operational Earth Science mission is presented. The Tropical Rainfall Measuring Mission (TRMM) was selected as an example that shows a typical Earth science mission with a nice complement of varying data rate instruments. We will be able to show through the satellite architecture where IP-based protocols will benefit a new design. Secondly, we develop an IP-based satellite bus design with an Ethernet backbone using standard terrestrial networking components and protocols. The design will be highly configurable to meet many different mission requirements. Adapting the design to the TRMM communications architecture will test the feasibility. We will indicate the subsystems that are part of the design and show examples of how TCP/IP will operate on board the satellite bus. Finally, we present the type of research needed to make IP-based missions a reality. This roadmap will provide NASA the guidance to design complex architectures that will become part of their mission portfolio in the next decade

MUST, SHOULD, DON'T CARE: TCP Conformance in the Wild

Standards govern the SHOULD and MUST requirements for protocol implementers for interoperability. In case of TCP that carries the bulk of the Internets' traffic, these requirements are defined in RFCs. While it is known that not all optional features are implemented and nonconformance exists, one would assume that TCP implementations at least conform to the minimum set of MUST requirements. In this paper, we use Internet-wide scans to show how Internet hosts and paths conform to these basic requirements. We uncover a non-negligible set of hosts and paths that do not adhere to even basic requirements. For example, we observe hosts that do not correctly handle checksums and cases of middlebox interference for TCP options. We identify hosts that drop packets when the urgent pointer is set or simply crash. Our publicly available results highlight that conformance to even fundamental protocol requirements should not be taken for granted but instead checked regularly

Sub-segment based transport layer protocol for wireless medium

This thesis discusses the techniques to improve the TCP over wireless. The loss-intensive wireless communication results in high retransmission rates to recover lost packets and bandwidth consumption. In addition, the retransmitted segments have significant chance of being dropped. To make the retransmission process more granular, large segments at the transport layer (540 bytes, by default) can be subdivided into smaller sub-segments. This document introduces a split TCP based solution and describes how to produce a series of smaller-sized segments that share the same transport layer header. A new header format is introduced to support the transmission of smaller segments and to conserve bandwidth during transmission. The NACK-based message exchange method is adopted with a special windowing protocol to achieve reliability, flow-control, and efficient buffer handling. The simulation results indicate that use of sub-segments improves latency, throughput, bandwidth, power and other measurements. In addition to that, an analytical model is developed to study the influence of sub-segmentation over latency and throughput