Tomasz Halapacz

7halat58@solent.ac.uk

Introduction

• Definition

• Background

• Overview of the technology

• Examples

• Summary

What is Delay Tolerant Networking

[DTN] DTNs=

oDisruption Tolerant Network

o Intermittently Connected Mobile Networks

[ICMNs]

o InterPlaNetary (IPN) Internet

• “Communication over vast distances where

end-to-end continuous connectivity is not

required “

(Cerf, et al., 2007)

Background

• In 1966 Leonard Kleinrock of MIT developed the theory of packet switching

• DARPA has funded NASA to develop Interplanetary Internet

• Vint Cerf and others has developed initial DTN architecture in July 1998. o The initial public announcement of this project can be found in

the JPL house journal .Available: Universe (7 August 1998)

• In 2002 Kevin Fall has proposed DTN acronym as Delay Tolerant Networks

• 2002- Delay-Tolerant Networking Research Group

Leonard Kleinrock

Vinton Cerf

Kevin Fall

(Farrell, S., 2006)

(Sterbenz, J., 2005)

(DTNRG., 2011)

http://universe.jpl.nasa.gov/un980807.pdfhttp://universe.jpl.nasa.gov/un980807.pdfhttp://universe.jpl.nasa.gov/un980807.pdf

When do we need DTNs? • Can be adapted to scenarios other than inter-planetary

communication

• To enable network access, when infrastructure is:

o difficult to deploy

o expensive to deploy

o available, but a DTN can still improve performance

(Cerf, V. et al., 2002)

Some real life examples where DTNs are being used…..

Infrastructure is difficult to deploy

• Wild-life tracking

Ze

bra

Net

pro

ject,

Kenya

(Princeton University. 2007)

Infrastructure expensive to deploy

• Providing Internet connectivity to developing regions. E.g., Email

KioskNet Project in India and Ghana

(Keshaw, S. 2009)

Interplanetary Examples

2008 November

• DINET 1 Test: Deep Impact DTN experiment: Moved

292 images (about 14.5 MB) through the DTN

network

2009 November

• DINET 2 postponed to 2011 due to Hartley 2 Comet

(NASA, 2010)

(NASA, 2010)

How it Works?

i

Destination

Intermediate

Source

• Store and

Forward

• Bundling

(Boucher, M. 2002)

Bundle Layer

• The figure below compares Internet protocol layers with DTN

protocol layers

• DTN operates over existing protocols and provide a gateway

when a node touches two or more dissimilar networks

Application

Network

Specific

Layers

Network

Specific

Layers

Network

Specific

Layers

Network

Specific

Layers

Application

Bundle Layer Application

Transport - TCP

Network - IP

Link

Physical

TCP/IP Model Mission Control Rover

Ground

Station

potential

delay

Source: Wartham, F. 2003. “Delay-Tolerant Networks (DTNs): Tutorial

Sattelite

Summary • DTN began intended as „Interplanetary Internet‟ for

deep-space connectivity, but is now also used for ad-hoc sensor networks.

• DTN Routers are equipped with significant persistent storage

• Data is moved like store-and-forward email messages in „bundles‟ between nodes, when limited connectivity becomes available

• Round-trip times could range from milliseconds to days

• Retransmission may be very expensive

Live Video from NASA 2011. NASA allows the public to watch technicians

assemble and test NASA's next Mars rover – “Curiosity”

Source: http://marsprogram.jpl.nasa.gov/msl/mission/whereistherover

now/

http://marsprogram.jpl.nasa.gov/msl/mission/whereistherovernow/http://marsprogram.jpl.nasa.gov/msl/mission/whereistherovernow/

Any Questions?

Thank You!

Tomasz Halapacz

7halat58@solent.ac.uk

References Aggelou, G. 2008. Wireless Mesh Networking, McGraw-Hill.

Anagnostopoulos, C. and S. Hadjiefthymiades .2010. "Delay-tolerant delivery of quality information in ad hoc networks." Journal of Parallel and Distributed Computing.

Boucher, M. 2002. The InterPlanetary Internet (IPN) [online] Available: http://images.spaceref.com/news/02.28.00.marsnetwork.jpg [accessed 27 February 2011]

Cerf, V. et al., 2002. Delay-Tolerant Network Architecture: The Evolving Interplanetary Internet, August.

Cerf, V. et al., 2007. Delay-Tolerant Network Architecture, IETF RFC 4838, informational, April.

Cerf. V, et al., 2001. Interplanetary Internet (IPN): Architectural Definition. Online] Available: http://www.ipnsig.org/reports/memo-ipnrg-arch-00.pdf [accessed 03 February 2011]

Durst, R. and Feighery, P. ,2006. Why not use the Standard Internet Suite for the Interplanetary Internet?, IPN Special Interest Group, (http://www.ipn-sig.org/reports/TCP_IP.pdf).

DTNRG., 2011. Delay Tolerant Networking Research Group [online] Available: http://www.dtnrg.org/ [last accessed 28 February 2011]

Fall, K. 2003. A Delay-Tolerant Network Architecture for Challenged Internets [online] Available: http://conferences.sigcomm.org/sigcomm/2003/papers/p27-fall.pdf [accessed 07 February 2011]

References Farrell, S. and V. Cahill (2006). Delay- and disruption-tolerant networking, Artech House.

Ivancic, W. et al. 2010. Large File Transfers from Space using Multiple Ground Terminals and Delay-Tolerant Networking. IEEE Global Communications Conference (Globecom), Miami [online] Available: http://personal.ee.surrey.ac.uk/Personal/L.Wood/publications/ivancic-globecom-large-file-dtn.pdf [accessed 05 February 2011]

Keshaw, S. 2009. The KioskNet Project Overview. [online] Available: http://blizzard.cs.uwaterloo.ca/tetherless/index.php/KioskNet [accessed 20 February 2011]

Meghanathan, N., B. Kaushik, et al. (2010). Advances in Networks and Communications: First International Conference on Computer Science and Information Technology, CCSIT 2011, Bangalore, India, January 2-4, 2011. Proceedings, Springer.

NASA. 2010. EPOXI Mission Overview [online] Available: http://epoxi.umd.edu/1mission/index.shtml [accessed 25 February 2011]

Princeton University. 2007. Zebranet Project Overview. [online] Available: http://www.princeton.edu/~mrm/zebranet.html [accessed 15 February 2011]

Scott, K. and Burleigh, S.2007, Bundle Protocol Specification, IETF RFC 5050, experimental, November.

Sterbenz, J. and Krishnan, R. 2005. Survivable and Disruption Tolerant Networking. [online] Available: http://www.sterbenz.org/jpgs/tutorials/sumowin-dtn/SUMOWIN-DTN-display.pdf [accessed 03 February 2011].

Vasilakos, A. (2011). Delay Tolerant Networks: Protocols and Applications, Taylor & Francis.

Warthman, F. 2003. Delay Tolerant Networks (DTNs): A Tutorial [online] Available: http://www.dtnrg.org/docs/tutorials/warthman-1.1.pdf [accessed 03 February 2011]

http://marsprogram.jpl.nasa.gov/msl/mission/whereistherovernow/

http://marsprogram.jpl.nasa.gov/msl/mission/whereistherovernow/http://marsprogram.jpl.nasa.gov/msl/mission/whereistherovernow/