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The Interplanetary Internet:Architecture and

Key Technical Concepts

By H.J.N.G.de Silva

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OverviewBrief description of Internet Society (ISOC)Basics of the IPN ArchitecturePossible ConfigurationsPower availabilityBackboneDesign Principles

Contents

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OverviewDr. Vinton Cerf is often cited as one of the internet’s founding fathers.

Future in which human intelligence is scattered all over the solar system.

People who surf the Internet today and tap websites in extreme locations such as Antarctica may some day be able to communicate to web or ftp servers on Martian micro-satellites to request data directly from Mars.

Imagine the Internet on Earth and a similar one on Mars linked by Gateways. These Gateways are satellites, which relay the information between the Internets.

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Similar Problems,Common Solutions

Fiber Satellites

Cable

Mobile/Wireless

WDM Terabit communicationslow delay

FTP/TCP/IPShort-haul communications

TerrestrialInternetStandards

Opportunity for leverage

S-bandX-band

Ka-band

LEOConstellations

MarsNetwork

Deep-spaceOptical

Megabit communicationshigh delay

Long-haul c

ommunicatio

ns

SpaceInternetStandards

File-basedOperations InterPlaNetary

InternetArchitecture

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Internet Society (ISOC)

InternetEngineering

SteeringGroup(IESG)

InternetArchitecture

Board(IAB)

InternetEngineeringTask Force

(IETF)

InternetResearch

Task Force (IRTF)

InternetCorporation for

Assigned Namesand Numbers

(ICANN)ICANN is the non-profit corporation that was formed to assume responsibility for the IP address space allocation, protocol parameter assignment, domain name system management, and root server system management functions

The IETF is a large open international community of network designers, operators, vendors, and researchers concerned with the evolution of the Internet architecture and the smooth operation of the Internet. It is open to any interested individual.

IRTF Research Groups work on topics related to Internet protocols, applications, architecture and technology. Participation is by individual contributors, rather than by representatives of organizations. The Internet Research Steering Group (IRSG) may from time to time hold topical workshops focusing on research areas of importance to the evolution of the Internet.

The IESG is responsible for technical management of IETF activities and the Internet standards process. The IESG is directly responsible for the actions associated with entry into and movement along the Internet "standards track," including final approval of specifications as Internet Standards.

IAB responsibilities include:1. IESG Selection, 2. Oversight of the architecture for the protocols and procedures used by the Internet. 3. Oversight of the process used to create Internet Standards.4. Editorial management and publication of the Request for Comments (RFC) document series5.External Liaison with other organizations concerned with standards and other issues relevant to the world-wide Internet. 6. Technical, architectural, procedural, and (where appropriate) policy advice to the Internet Society

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Internet Research Task Force (IRTF)

AuthenticationAuthorisationAccounting

Architecture(AAAARCH)

BuildingDifferentiated

Services(BuDS)

End-to-End(E2E)

InternetResourceDiscovery

(IRD)

InterplanetaryInternet(IPNRG)

NetworkManagement

(NMRG)

NameSpace(NSRG)

ReliableMulticast Routing

SecureMulticast(SMuG)

ServicesManagement

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IPNSIG

Public

DARPA-NASAInterplanetary

InternetArchitecture

International SpaceCommunications Infrastructure

Standardization Options

IPNRG

Open ArchitectureOpen SpecificationsOpen Implementations

Communicationsrequirements

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Interplanetary Internet Special Interest Group

IPNSIG formed in September of 1999.Open to all Internet Society membersPurpose

To serve Internet Society members interested in the development and use of an Interplanetary Internet.To encourage the beneficial, open evolution of the global Internet and its related internetworking technologies beyond planet Earth.

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Space explorationbecomes fullyInternet-based

Remoteinternets

are deployed in space

Aninterplanetary

backbonenetwork

is deployed

Missions log-onto the

“InterplanetaryInternet Service

Provider” tocommunicate

Basics of the IPN Architecture

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The InterPlanetary Internet

Public involvementin voyages of discovery

“Plug-and-Play”communicationsinfrastructure

Web-basedscientific

investigation

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In-situ Internets

Security

InterplanetaryGateways

Inter-InternetDialog

InterplanetaryBackbone

Key Technologies

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Some Functions of Deployed Internets

Science Data and Telemetry ReturnCommand and Control of In-Situ ElementsTelescience/Virtual Presence

Initially back-hauled to earthSecondarily, in support of robotic control of robotic explorationEventually, in support of human in situ control of robotic exploration

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Differences between IPN remotely-deployed internets and the terrestrial Internet

Terrestrial“Wired”

Terrestrial“MANET”

IPN in-situ“Wireless”

Poweravailability Not critical Important Of overriding

importance

Signal-to-Noise Ratios Fiber clean

Low SNRf(power, node

density)Very low SNR

f(power)

Infrastructure Fixed Deployable,mobile

Transmissionmedium Fiber, copper Free space

RF, IRPrimarily free space

RFDeployment Cost Relatively low Moderate High, f(mass)

Operational Cost Relatively lowRepair, upgrade Cost Relatively low Very high

Deployable, mobile

High, f(reliability)

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Power Availability Makes Mitigation of Differences More Difficult

Power availability affects all aspects of deployed internet operation

Solar conversion is the primary power source for foreseeable futureExample: The average solar intensity in Mars orbit is 590 W/m2, compared with 1370 W/m2 in Earth orbitSurface-based solar panels are subject to

Atmospheric dust limiting available solar energyDust build-up on/erosion of solar panels, reducing effectiveness over timeLocation-based reductions in solar intensitySeasonal variations in solar intensity

Efficiency of communication at all layers is required to offset the limitations of power availability

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What’s a Backbone?

A set of high-capacity, high-availability links between network traffic hubs

Terrestrial backbone linksInterplanetary backbone links (between hubs like Earth and Mars)

In-situ Internets

Security

InterplanetaryGateways

Inter-InternetDialog

InterplanetaryBackbone

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Differences Between Terrestrial and Interplanetary Backbones

Terrestrial InterplanetaryDelay (sec) < .1 10 to 10,000

Connectivity Wired; structural,continuous

Radiant; operational,intermittent

Medium Copper, glass Space; high BER

Deployment Cost “low” Very high

Operations Cost “low” High (power is costly)

Repair, upgrade Cost

“low” Very high

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What Won’t Work

Absence of automated protocol It doesn’t scale up. Network operations cost would be too high.Internet protocols (TCP, UDP, IP) or other protocols designed for terrestrial networks.

They rely on conversational protocol mechanisms and/or continuous end-to-end connectivity.

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What To Do Instead

New application protocols

New bundle-oriented protocols

New reliable link layer protocol.

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Resulting Backbone Differences

Terrestrial Interplanetary

Transport TCP bundling

Network IP bundle routing

Link SONET “LTP” / CCSDS

Physical Optical fiber R/F or laser

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Challenges in Deep Space Time Synchronization

Variable and long transmission delaysThe long and variable delays may cause a fluctuating offset to the clock

Variable transmission speedIt may produce a fluctuating offset problem

Variable temperatureIt may cause the clock to drift in different rate

Variable electromagnetic interferenceThis may cause the clock to drift or even permanent damage to the crystal if the equipment is not properly shielded

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Multimedia Transport in InterPlaNetary Internet

Additional Challenges

* Bounded Jitter* Minimum Bandwidth* Smoothness* Error Control

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Planned InterPlaNetaryInternet Missions

To study Mercury’s form, interior structure, geology, composition, etc.January 2011BepiColombo

Smart Lander, Long Range Rover and Communication Satellite.Late 2009Mars 2009

To launch a remote sensing orbiter and four small Netlanders to Mars. Late 2007Mars 2007

To probe the gravity waves emitted by dwarf stars and other objects sucked into black holes.

2007LISA

To study the Jupiter’s Moon Europa’s icy surface.2008Europa Orbiter

Search for terrestrial planets, i.e., similar to Earth.October 2006Kepler

To study two of the largest asteroids, Ceres and Vesta.May 2006Dawn

To fly by Pluto and its moon Charon and return scientific data/images.January 2006New Horizons

To study the atmosphere and plasma environment of Venus.November 2005Venus Express

To study Mars from orbit, perform high-resolution measurements and serve as communications relay for later Mars landers until 2010.

July 2005Mars Reconnaissance Orbiter

To investigate the interior of the comet, the crater formation process, the resulting crater, and any outgassing from the nucleus.

December 2004Deep Impact

To study the characteristics of Mercury, and to search for water ice and other frozen volatiles.

March 2004Messenger

Comet orbiter and lander to gather scientific data.February 2004Rosetta

To measure star formation 11 billion years ago with UV wavelengths.2003Galaxy Evolution Explorer

Description/ObjectiveScheduleMission Name

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Conclusions

InterPlaNetary Internet will be the Internet of next generation deep space networks.

There exist many significant challenges for the realization of InterPlaNetary Internet.

Many researchers are currently engaged in developing the required technologies for this objective.

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References

http://www.ipnsig.org/techinfo

http://www.cewit.org/InterPlanetary

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Thank You