Routing Algorithm for LEO Satellite Networks : A Survey
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 : [email protected]
Guided By:
Dr. Shiva Murthy G Associate Professor
Department of Information science and Engineering
Acharya Institute of Technology
Bangalore – 560090, India
Email : [email protected]
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.