Geographic Centroid Routing for Vehicular Networks

A number of geolocation-based Delay Tolerant Networking (DTN) routing protocols have been shown to perform well in selected simulation and mobility scenarios. However, the suitability of these mechanisms for vehicular networks utilizing widely-available inexpensive Global Positioning System (GPS) hardware has not been evaluated. We propose a novel geolocation-based routing primitive (Centroid Routing) that is resilient to the measurement errors commonly present in low-cost GPS devices. Using this notion of Centroids, we construct two novel routing protocols and evaluate their performance with respect to positional errors as well as traditional DTN routing metrics. We show that they outperform existing approaches by a significant margin.Comment: 6 page

Implementation of Epidemic Routing with IP Convergence Layer in ns-3

We present the Epidemic routing protocol implementation in ns-3. It is a full-featured DTN protocol in that it supports the message abstraction and store-and-haul behavior. We compare the performance of our Epidemic routing ns-3 implementation with the existing implementation of Epidemic in the ONE simulator, and discuss the differences

End-to-End Resilience Mechanisms for Network Transport Protocols

The universal reliance on and hence the need for resilience in network communications has been well established. Current transport protocols are designed to provide fixed mechanisms for error remediation (if any), using techniques such as ARQ, and offer little or no adaptability to underlying network conditions, or to different sets of application requirements. The ubiquitous TCP transport protocol makes too many assumptions about underlying layers to provide resilient end-to-end service in all network scenarios, especially those which include significant heterogeneity. Additionally the properties of reliability, performability, availability, dependability, and survivability are not explicitly addressed in the design, so there is no support for resilience. This dissertation presents considerations which must be taken in designing new resilience mechanisms for future transport protocols to meet service requirements in the face of various attacks and challenges. The primary mechanisms addressed include diverse end-to-end paths, and multi-mode operation for changing network conditions

A Distributed Platform for High-Speed Active Network Topology Discovery

Sponsored Research ArticleNaval Postgraduate School Cyber Academic Grou

Effective C2 Comms to the Tactical Edge in Challenged, Disrupted, and Denied Environments

Native IP networks are ill-equipped to handle the communication challenges found in wireless comms environments, resulting in communications outages that degrade C2 data flow and subject the user to disconnection, timeouts, and repeated login requests. We counter these limitations by integrating DTN (Disruption-Tolerant Networking) technology into the IP network using software+hardware or software-only solutions as appropriate. This work evaluates the tradeoffs between the currently available DTN software implementations and seeks to identify the one with the highest technical readiness level, as well as any barriers to adoption that may be present. We find that no current implementation is fully ready, and that each have particular pros and cons to adoption.Naval Research ProgramPrepared for Topic Sponsor: Maj Jeffrey Sykes, USMC, HQMC Aviation; Research Sponsor HQMC Aviation; Research POC Name: Maj Scott CuomoN16-M343-

Whale of a crowd: Quantifying the effectiveness of crowd-sourced serious games

Abstract—In this paper we analyze several Crowd-Sourced Serious Games (CSSGs), a new genre focused on advancing widely respected causes such as social equality and science. We observe that the general effectiveness of these games has remained largely unknown. Existing performance analyses have been limited to documenting experiences with individual systems. More importantly, existing game analytics approaches are designed for games that provide personal experience and entertainment. In contrast, CSSGs attract participants by evoking their sense of social responsibility and sympathy for others. Intuitively, social awareness and sympathy alone may not result in the same level of consistent participation as personal achievement, or fun. Consequently, the success of a CSSG may be more tightly linked to the contributions of few highly-dedicated players (whales)

Ferritins: furnishing proteins with iron

Ferritins are a superfamily of iron oxidation, storage and mineralization proteins found throughout the animal, plant, and microbial kingdoms. The majority of ferritins consist of 24 subunits that individually fold into 4-α-helix bundles and assemble in a highly symmetric manner to form an approximately spherical protein coat around a central cavity into which an iron-containing mineral can be formed. Channels through the coat at inter-subunit contact points facilitate passage of iron ions to and from the central cavity, and intrasubunit catalytic sites, called ferroxidase centers, drive Fe2+ oxidation and O2 reduction. Though the different members of the superfamily share a common structure, there is often little amino acid sequence identity between them. Even where there is a high degree of sequence identity between two ferritins there can be major differences in how the proteins handle iron. In this review we describe some of the important structural features of ferritins and their mineralized iron cores and examine in detail how three selected ferritins oxidise Fe2+ in order to explore the mechanistic variations that exist amongst ferritins. We suggest that the mechanistic differences reflect differing evolutionary pressures on amino acid sequences, and that these differing pressures are a consequence of different primary functions for different ferritins

Graph reduction for emulated network experimentation

Network researchers and operators often turn to emulation and simulation for testing and experimentation.Obtaining topologies that reflect the graph characteristics of the Internet, while of small enough order to emulate or simulate on commodity hardware, however, is a difficult undertaking.In this work, we reexamine a previous study devoted to generating Internet-like topologies by reducing Autonomous System-level Internet instances to a more manageable scale.In addition to replicating the original experiment using Routeviews data from 2001, we extend the prior work’s methodology to more current data and to another data set compiled by the Center for Applied Internet Data Analysis.Finally, we introduce a new Internet graph reduction method, and examine its performance on both data sets.Approved for public release; distribution is unlimited

DTN Hybrid Networks for Vehicular Communications

2013 International Conference on Connected Vehicles and Expo (ICCVE)The article of record as published may be found at http://dx.doi.org/10.1109/ICCVE.2013.25We present an architecture for combining two established network paradigms, IP and Disruption-Tolerant Networking (DTN), into a unified packet gateway design that leverages the advantages of both. Vehicular networking (VNET) scenarios often involve brittle links between communicating nodes due to their mobility. DTN solutions, by using a dynamic hopby- hop delivery model instead of the end-to-end IP model, are able to sustain a large class of applications despite intermittent links. As a defining characteristic, our design is applicationtransparent in that it requires no changes to host applications (or the underlying host protocol stacks) in order for them to use DTN transport when IP is not feasible. In addition, we build into the architecture an explicit disruption notification service for keeping users informed as well preventing application time-outs during an IP outage. Finally, given the wide range of behaviors exhibited by applications that can benefit from DTN, our design supports the notion of an application lattice to allow operators to customize, on a per application/group/protocol basis, how the switch between IP and DTN and the disruption notification are performed. A preliminary evaluation based on a C++ proof-ofconcept implementation has illustrated several potential benefits of the proposed architecture for VNET applications

DTN Gateway Architecture for Partially Disconnected Telemetry Environments

Proceedings of the International Telemetering Conference (ITC), October, 2012.Telemetry networks often operate in challenged wireless environments, resulting in periods of disconnection. Our delay tolerant networking (DTN) gateway dynamically detects disruptions in connectivity and buffers telemetry data until connectivity is reestablished. When the connection is resumed, all buffered data is transmitted automatically in order to backfill any gaps in the telemetry stream. A DTN gateway may operate as a standalone device with multiple DTN client applications, or as a network of mobile DTN gateways which will perform multi-hop ad-hoc routing to deliver telemetry data across the telemetry network system (TmNS). Our DTN gateway also provides conventional IP routing and forwarding capabilities, including support for standard dynamic routing protocols, eliminating the need for a stand-alone IP router on the test article (TA). This paper presents the system architecture of our DTN gateway, along with several deployment scenarios for telemetry environments