Leo satellite networks

Routing Algorithm for LEO Satellite Networks : A Survey

A Presentation by:

Saif ShamimStudent - Department of Information science and Engineering

Acharya Institute of Technology

Bangalore – 560090, India

Email : saifshamim.ise.09@acharya.ac.in

Guided By:

Dr. Shiva Murthy G Associate Professor

Department of Information science and Engineering

Acharya Institute of Technology

Bangalore – 560090, India

Email : shivamurthyg@acharya.ac.in

Introduction

GEO

MEO

HEO

LEO

Types of SatellitesGeostationary/

Geosynchronous Earth Orbit Satellites (GSOs) (Propagation Delay: 250-280 ms)

Medium Earth Orbit Satellites (MEOs) (Propagation Delay: 110-130 ms)

Highly Elliptical Satellites (HEOs) (Propagation Delay: Variable)

Low Earth Orbit Satellite (LEOs) (Propagation Delay: 20-25 ms)

HEO: var. (Molniya, Ellipso)

LEO: < 2K km

MEO: < 13K km (Odyssey, Inmarsat-P)

GEO: 33786 km

(Globalstar, Iridium, Teledesic)

This slide is taken from:Ian F. AkyildizSatellite networksGerogia Institute of Technology, USA

Geosynchronous Orbit (GEO): 35,786 km above the earth

A geosynchronous satellite is a satellite in geosynchronous orbit, with an orbital period the same as the Earth's rotation period.

There are approximately 300 operational geosynchronous satellites.

These can remain at one position for infinite time.

Medium Earth Orbit (MEO): 8,000-20,000 km above the earth

Medium Earth orbit (MEO), sometimes called intermediate circular orbit (ICO), is the region of space around the Earth above low Earth orbit and below geostationary orbit.

Telstar 1, an experimental satellite launched in 1962.

Highly Elliptical Orbit Satellites (HEOs)

From a few hundreds of km to 10s of thousands allows to maximize the coverage of specific Earth regions.

Variable field of view and delay.

Examples: MOLNIYA, ARCHIMEDES (Direct Audio Broadcast), ELLIPSO.

This slide is taken from:Ian F. AkyildizSatellite networksGerogia Institute of Technology, USA

Low Earth Orbit (LEO): 500-2,000 km above the earth

A low Earth orbit (LEO) is generally defined as an orbit below an altitude of approximately 2,000 kilometers.

A majority of artificial satellites are placed in LEO.

Examples: Earth resource management

(Landsat, Spot, Radarsat) Paging (Orbcomm) Mobile (Iridium) Fixed broadband (Teledesic,

Celestri, Skybridge)

Architecture of LEO

Communications data passes through a satellite using a signal path known as a transponder.

Typically satellites have between 24 and 72 transponders. A single transponder is capable of handling up to 155 million bits of information per second.

With this immense capacity, today's communication satellites are an ideal medium for transmitting and receiving almost any kind of content - from simple voice or data to the most complex and bandwidth-intensive video, audio and Internet content.

Why LEO Satellite Networks?

Less Propagation Delay

High Throughput

Flexible Bandwidth

Digital Earth and Tele-Education

Easy Integration

Will Play an Important Role in Next Generation Networks (NGN)

Applications of Satellite Networks

Telecommunication

Earth Observation

Military Operations

Natural Calamities

Broadcasting Internet

Routing Parameters

Packet Loss Rate

Delay Jitter

Throughput

Delay

Average Node Throughput

Classification of Routing Algorithms

Steiner Tree Routing

Destruction Resistance Routing

Minimum Flow Maximum Residual

BDSR Routing Algorithm

A Handover Optimize Routing

Contd…

Connection Oriented Routing

Routing Based On Ground Station

Optimization of Delay and Bandwidth

High Performance Routing

Distributed Multipath Routing

Classification of Routing Algorithms

Classes of LEOs

Little LEOs

–Non-voice services

–Orbcomm

–LEO One

–Final Analysis

Broadband LEOs–High-speed data plus voice–Teledesic–SkyBridge

Big LEOs–Voice plus limited data services–Iridium–Globalstar–Constellation Communications This slide is taken from

Christhoper Reeding,Overview of LEO Satellite SystemsNational Communication & Information Administration, USA

Open Issues

Swarn Intelegence

A Handover Problem

TO satisfy all QoS Constraints

To Reduce Onboard Complexity

Combining GEO and LEO advantages

Conclusions

GEO Satellite Networks have advantage of technological maturity and good coverage.

GEO Satellite Networks are suffering form high delay and attenuation limits transmitting real time information.

Today LEO satellite networks are most commonly used

in broadcasting Internet. Due to low cost and high data transmission rate these LEO satellite networks are the preferred choice of the vendors.

Thank You

References

1. Satellite Networks, Ian F. Akyildiz Georgia Institute of Technology, USA.

2. Overview of LEO Satellite Systems, Christhoper Reeding, National Communication & Information Administration, USA.

3. Dynamic Routing With Link State Information in ADNS and future SATCOM Networks, Jun Sun, Mu-Cheng, Lorraine Prior, Terrence Gibbons & Jeff Wysocarski, MIT Lincoln Laboratory USA.