Probabilistic Routing Protocol for Intermittently Connected Networks

This document is a product of the Delay Tolerant Networking Research Group and has been reviewed by that group. No objections to its publication as an RFC were raised. This document defines PRoPHET, a Probabilistic Routing Protocol using History of Encounters and Transitivity. PRoPHET is a variant of the epidemic routing protocol for intermittently connected networks that operates by pruning the epidemic distribution tree to minimize resource usage while still attempting to achieve the best-case routing capabilities of epidemic routing. It is intended for use in sparse mesh networks where there is no guarantee that a fully connected path between the source and destination exists at any time, rendering traditional routing protocols unable to deliver messages between hosts. These networks are examples of networks where there is a disparity between the latency requirements of applications and the capabilities of the underlying network (networks often referred to as delay and disruption tolerant). The document presents an architectural overview followed by the protocol specification

The Evolution of a DTN Routing Protocol - PRoPHETv2

Research within Delay- and Disruption Tolerant Networks (DTN) has evolved into a mature research area. PRoPHET is a routing protocol for DTNs that was developed when DTN research was in its infancy and which has been studied by many. In this paper we investigate how the protocol can evolve to meet new challenges that has been identified through research and practical experience. We propose some minor modifications to the routing metric cal- culations done in PRoPHET which has potential to alleviate some issues and improve the performance of the protocol. Using these modifications, we define an updated version of the protocol called PRoPHETv2. We run simulations to verify the operation of the protocol and compare its performance against the original version of the protocol as well as some other routing protocols. The evalua- tions are done using both traces from an existing DTN deployment and a synthetic mobility model. Since the basic mechanisms of the protocol remain the same, migrating existing implementations to the new version of PRoPHET is possible with limited effort

Not-so-instant-messaging service for the delay tolerant networks

Most of the research within the Delay Tolerant Network(DTN) area focuses on the networking layer and therouting of network traffic. In order to move the DTNresearch from the networking research area to the realworldusage the developments of services andapplications that uses DTN are crucial. This paperpresents the Not-So-Instant-Messaging (NSIM) servicedesigned for DTN usage. The NSIM service allows usersof the DTN to send and receive E-Mails, send out SMSand communicate efficiently with other users within theDTN region.Godkänd; 2011; 20120904 (samo

Development and Deployment of Delay Tolerant Networks: An Arctic Village Case

In the late 1990s, NASA conducted a study of the Interplanetary Internet (IPN) architecture. In order to build and deploy IPN infrastructure, the network technology had to be able to cope with long radio signal propagation delays and frequent radio link disruptions. The concept of a Delay Tolerant Networking (DTN) emerged after recognizing that such a networking paradigm can also be applicable for terrestrial use. DTN technology can be applied, for instance, in disaster situations, military battlefields, economically developing areas, and remote regions.This thesis follows the process of applying DTN technology to a remote, communication-challenged area in the Arctic part of Sweden. The aim of the DTN deployments in the remote villages of Sarek and Padjelanta National Parks, between 2008 and 2011, was to provide a basic set of ICT services to the nomadic Sami population. Therefore, the research presented here acknowledges and considers the specific geographical, technical, and cultural conditions of these areas, and how these conditions profoundly shaped the development of the deployed technology as well as the research methodology. As a result, this thesis makes scientific contributions to several research topics, spanning the fields of DTN routing, DTN service development, DTN evaluation methodologies, and ICT deployments.The first contribution in this thesis is the proposal of a new and improved version of the PRoPHETv2 routing protocol. The development of this routing protocol was driven by actual protocol use and the results of experiments conducted during the course of the DTN deployments.Secondly, this thesis proposes an alternative DTN routing objective for a typical remote village DTN scenario. Weaknesses of a conventional DTN routing research objective are exposed by outlining concrete geographical, social, and technical conditions discovered in DTN deployments on the field. When these conditions are overlooked, they can profoundly affect DTN deployments.Thirdly, this thesis discusses the development and deployment of the Not-So-Instant-Messaging (NSIM) DTN service. The NSIM service was designed to leverage from the decentralized DTN infrastructure. Its success in the field demonstrates the importance of localized DTN services. Fourthly, using qualitative reading of DTN routing related papers, this thesis describes shortcomings of established DTN routing evaluation methodologies. Extensive use of simulated environments and scarce real-world experiments in the DTN research field often leads to usage of specific hypothetical scenarios. These scenarios are difficult to compare or relate to each other. Additionally, DTN research that does contextualize itself in remote, extreme, and challenging scenarios performs evaluations of proposed routing schemes in urban or academic environments. The DTN evaluation model that is proposed here tries to improve the readability, comparability, and validity of DTN routing evaluations. This thesis also pays attention to the issue of how to evaluate the complex interplay that occurs between researchers, users, technology and environment throughout the deployment process. The suggested method highlights the dynamics of resistance, as conceptualized within Actor Network Theory (ANT). It illustrates how employment of the concept of resistance facilitates the recognition of different driving forces in the design process that emerge from the events in the deployment.Ultimately, the thesis contributes with the PRoPHET routing protocol specification in the "Request for Comments" (RFC) document series that is the official publication channel for the Internet Research Task Force (IRTF) and other Internet communities. The protocol specification published as the RFC6693 document allows for actual protocol implementation and assures interoperability. The discussion that follows the RFC document in this thesis focuses on the process of transferring scientific findings gained from the experiments on the deployment field into the Internet draft document that was finally recognized as an experimental RFC within the IRTF.Godkänd; 2014; 20140407 (samo); Nedanstående person kommer att disputera för avläggande av teknologie doktorsexamen. Namn: Samo Grasic Ämne: Arbetsvetenskap/Human Work Science Avhandling: Development and Deployment of Delay Tolerant Networks: An Arctic Village Case Opponent: Professor Lars Wolf, Institut für Betriebssysteme und Rechneverbund, Technische Universität Braunschweig, Tyskland Ordförande: Docent Maria Udén, Avd för arbetsvetenskap, Institutionen för ekonomi, teknik och samhälle, Luleå tekniska universitet Tid: Måndag den 12 maj 2014, kl 10.00 Plats: A109, Luleå tekniska universitet För Tekniska fakultetsnämndenNetworking for Communications Challenged Communities: Architecture, Test Beds and Innovative Alliance

An Analysis of Evaluation Practices for DTN Routing Protocols

Over the past decade, a lot of research has been done to develop efficient routing protocols for Delay- and Disruption Tolerant Networks (DTNs). In the course of this work, many comparative evaluation studies have been done to determine which of two proposed protocols is the better one (for a given situation). The majority of these evaluations are based on results gained from simulated network environments. In order to conduct a relevant evaluation of routing schemes, numerous conditions, policies and data need to be specified and fed into the simulation environment. The aim of our work in this paper is to discuss current DTN evaluation practices through a thorough and critical literature study. Based on the surveyed material, we show some weaknesses and lack of argumentation used in the evaluations. Through this, we hope to aid in bridging the gap between simulated and real-world DTN environments. In addition, and as a call for further research, we propose a model for evaluation of DTN routing schemes that outlines the most crucial inputs that needs to be considered in the evaluation process. This model is then projected onto evaluation practices used for evaluations of DTN routing protocols in a set of sixteen papers roughly covering a decade of DTN research.CN

How the library better can support students to analyze and evaluate sources when using popular media platforms

Printed material is no longer the only source for information. The media landscape of today consists more and more of films, vlog and video. Despite this, printed sources are often the only referred to in the students' academic work. Umeå University Library conducted interviews and workshops with student groups from different disciplines. From this we learned that the library can play a crucial role to facilitate guidance to evaluate the reliability and credibility of films and how to cite different online sources. Together with HUMlab we aim to develop a new way of guiding the students in source criticism, both in technical and pedagogical aspects.

NomaTrack and the LoRa-DTN protocol : DTN in innovation for reindeer husbandry

The NomaTrack design combines the LoRa‐DTN protocol with a set of unique equipment units. The equipment set consists of the units base station, reindeer GPS collar, and portable node. Drones are utilized to create line‐of‐sight. With this set reindeer positions are tracked. Real life on‐site tests integrated in herding operations were essential. They involved Jåhkågaska, Sirges, Tuorpon and Udtja Sámi Villages in Norrbotten, Sweden. In the concluding tests November‐December 2020 the deployed network extended reindeer tracking beyond regular infrastructure and connectivity with approximately 300 units. The system remains in use after the project ended. From mid‐November totally 5000 or up to more than 6000 bundles were delivered daily. Into January the number of active nodes in the LoRA‐DTN has been about 145 to 180 per day. The NomaTrack connectivity concept offers an opportunity for messaging. During the project here reported, the design of such a service was drafted. Development ofthe messaging function will commence during 2021.Sponsorship of NomaTrack and the LoRaDTN protocol 2020. Project support from GooglePlaneringsverktyg för rennäringsföretag - teknikutveckling inom renskötseln, Europeiska Jordbruksfonden för Landsbygdsutvecklin