DTN Applications-Overview
From N4C
The N4C project is developing applications using the Delay-Tolerant Networking (DTN) technology. The DTN technology is developed under the scope of networks working in extreme environments where there isn’t guarantee of continuous end-to-end connectivity. The applications provide the connection between technology and the users. This page is divided into five sections: DTN Concept, Web Caching, Email/Not So Instant Messenger, Hiker's Applications and Meteorological Data Transfer.
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DTN Concept
DTN technology addresses a wide range of technical problems, from interplanetary applications to terrestrial applications, where it is not possible to reduce latency to the values needed for today’s Internet. This kind of applications goes from methods of delivering information related to global warming to ways of including remote populations in the opportunities of modern Internet society.
It also supports the capability of using different transport protocols in different parts of the network. Existing capability, as included in the publicly-available DTN reference implementation (Kevin Fall 2005), operates as a store-and-forward routing and session layer protocol, creating network connections when appropriate, or re-creating them when they have failed. This is important for communication in remote areas because such communication normally has the combined characteristics of high delay, high cost, and high loss rate.
The development of DTN technology is fully integrated in the standardization processes through the Delay Tolerant Networking Research Group within the Internet Research Task Force (IRTF DTNRG, currently chaired by Kevin Fall, Intel/Berkeley and Stephen Farrell, Trinity College Dublin).
The initiative of using DTN for nomadic use in remote areas has been developed in the context of Sámi Network Connectivity (SNC) project. The N4C project derivates from the SNC project and adopts this initiative of use DTN technology to develop applications focused in the rural areas usability.
See more about DTN concept in http://www.dtnrg.org/wiki and http://en.wikipedia.org/wiki/Delay-tolerant_networking.
Web Caching Application
Web Caching Application allows DTN users to receive all the information needed from a particular web page or group of web pages through a single request made to a gateway in the legacy Internet. The objective will be to make this operation as transparent as possible to the user with a standard web browser, even when synchronous retrieval of the information is not possible, and that the system is intelligent enough to deliver sufficient information to display the requested page(s) from a single bundle of information returned via the DTN. The project will also implement a ‘push’ model in which bundles of information can be pro-actively delivered to gateways within the DTN, by the network, either on a regular time schedule (e.g., to deliver news information on a daily basis) or as a result of actions by a user.
This application has the following functionalities:
- User pulled regular: a user can request that some data/webpages should be delivered regularly;
- User pulled event driven: a user can set up a cache in advance;
- Provider pushed regular: provide information regularly - important to increase the tourism, important to the education (packages of educational material appropriate to a particular student, selected by a remotely located teacher), and so on;
- Provider pushed event driven: sends data to cache in advance;
- Ad hoc site request: a user tries to access a site that is not normally cached;
- Ad hoc search request: a user makes a search request through a search box.
This application should have the following input: site/search requests from clients using ad hoc TCP/IP mode in the DTN regions and data from providers using TCP/IP in the common Internet. The answer to the input should be the delivery of the requested data to the client.
Email/Not So Instant Messenger Applications
The aim of the Email/Not So Instant Messenger Applications is to work like the conventional Email/Instant Messenger, adapted to the DTN reality.
These applications have following functionalities:
- The first one is to send and receive emails to/from DTN regions (the emails' destination/source can be located in the common Internet).
- The latter is a “Not so” Instant Messenger, similar to Microsoft Windows messenger, but working in an asynchronous way.
Both of these functionalities can use text or attachments. The “Not so” Instant Messenger will be implemented within the DTN network only to guarantee the correct work of this functionality.
The inputs of these applications are the emails/messages sent out by the DTN users and the output is the delivery of emails/messages to the destination.
Hiker's Applications
The Hiker’s PDA Applications are focused in convenient assistance of the DTN user (e.g. tourists and investigators) with some services, such as emergency services.
These applications have the following features:
- Points of Interest (POI) – The functionalities of this application are to download potential interest points like heart starter, medical or physical services. The module should be able to extract GPS maps with the location of interest points, from the web cache/internet. For example, the location of the nearest medical services (medical, physical or heart starter) can be one type of Point of Interest (POI). The input of the application is the current location, given by the GPS receiver’s coordinates and the output is the POI database updated.
- Send a Message with own location – This application should be able to send a message with GPS receiver’s own location in a DTN region and forward it to the LI. The input of this application is the GPS receiver’s coordinates and the output is the email containing those coordinates.
- Maps for Own Location – Download maps related to one’s location. The application should be able to pull up a map of the area around the current GPS receiver’s coordinates. The input of this application is the GPS receiver’s coordinates and the output is the updated cached maps.
- Geoblog and Photo Blog – Must be able of automatic updates of geoblog and photo blog when there is a connection opportunity. The input of this functionality is the GPS receiver’s coordinates and the output is the email with the GPS receiver’s coordinates.
Meteorological Data Transfer Application
These applications are important both in support of today’s activities in rural areas, including animal herding and eco-tourism, and also in support of longer term needs, like monitoring the environment in areas where local data collection is currently intermittent or non-existent. The International Panel on Climate Change (IPCC) has identified [IPCC07] the risks to the global economy from climate change and there is a need to collect environmental data from all regions of the globe both to assist with immediate weather forecasting and to monitor the longer term effects on the global climate.
The main functionality of this application is to transmit meteorological data from the DTN regions to common Internet. The data is composed of the following meteorological sensors measures:
- temperature
- relative humidity
- wind’s speed and direction
- pressure
- solar radiation
- precipitation
The data files are delivered in ASCII format.
Tracking Animals Application
The Tracking Animals Application is intended to monitor both terrestrial and marine wild animal populations.
In the N4C project, this application focus in the economically important species in the Arctic region, specifically in the reindeer herds, the basis of traditional economic activity in the Sápmi region, that roam freely over very wide areas. The main target of this application is to provide a cost-effective way to monitor the location of the individual animals.
