This document discusses VSAT (Very Small Aperture Terminal) technology for connecting remote sites via satellite. It provides an overview of VSAT components and configurations, as well as advantages such as availability, fast deployment, and reliability compared to other connectivity options. Different types of satellite orbits - geostationary, medium earth, and low earth - are described along with their implications for latency, coverage, and system complexity.

1. VSAT–viable solution for remote sites connectivityBY:Syed Khurram Iqbal NaqviSystem Architect O3B NetworksFor Pakistan and Central Asia

2. VSAT (Very Small Aperture Terminal)A Very Small Aperture Terminal (VSAT), is a two-way satellite ground station with a dish antenna that is smaller than 3 meters. VSATs access satellites to relay data from small remote earth stations (terminals) to other terminals (in mesh configurations) or master earth station "hubs" (in star configurations).

3. Motivation to use VSATVSHard to reach areasReliability Time to deploy (4-6 months vs. 1-2 weeks)Cost ( If distance is more than 500 km then the VSAT solution is more cost-effective as compared to the optical fiber.)Emergency Situations

4. Satellite Services & ApplicationsVoice/Video/Data CommunicationsMobile Telephony

5. Rural Telephony

6. News Gathering/Distribution

7. Internet Trunking

8. Corporate VSAT Networks

9. Distance-Learning

10. Videoconferencing

11. Business Television

12. Broadcast and Cable Relay

13. VOIP & Multi-media over IPGPS/Navigation Position Location

14. Timing

15. Search and Rescue

16. Mapping

17. Fleet Management

18. Security & Database Access

19. Emergency Services Remote Sensing Pipeline Monitoring

20. Infrastructure Planning

21. Forest Fire Prevention

22. Urban Planning

23. Flood and Storm watches

24. Air Pollution ManagementDirect-To-Consumer Broadband IP

25. Digital Audio Radio

26. Interactive Entertainment

27. Video & Data to handheldsOccasional Use ServicesNewsgathering – First choicefor live coverage, providinghigh-bandwidth video links from remote locations to capture “breaking news”

28. Program Delivery – Broadcasts from television networks and relayed via satelliteUsers of Satellite CommunicationsBanking SectorData NetworksTelecommunications (Cellular) Power ProductionInfrastructureOil & Gas

29. AdvantagesAvailability: anywhere—no limitationsFast Deployment: Within hours!Homogeneity: Same speed and SLA regardless of locationMulticast: broadcast schemes which allows broadcast at no additional costFew Points of Failure: just two on the earth!

30. Advantages (contd.)Reliability:reliable satellite transmission of data between an unlimited number of geographically dispersed sites Flexibility:expansion capabilities, unrestricted and unlimited reach.Network Management:end-to-end monitoring and configuration control for all network subsystems.A low mean-time to repair - lesser elements imply lower MTTR.

31. DisadvantagesLatency: round trip delay of 500ms or even more!Cost of Bandwidth:high as compared to others! Environmental concerns:“fading” due to rain/snow (frequency band dependent)LOS dependency:outdoor antenna installation requires clear LOS.Interference:common to all wireless media!

32. Comparison between Transmission MediaOptical FiberMicrowaveCopperVSAT

33. Satellite-Fiber ComparisonComparing Satellite and Fiber CharacteristicsCapabilityFiber Optic Geo Satellite in a Meo Satellite in a Leo Satellite in aCableGlobal SystemGlobal SystemConstellationSystemsTransmission 10 Gbps-3.2 Single SatSingle SatSingle SatSpeedTerabits/second*1 Gbps-10 Gbps0.5 Gbps- 5 Gbps.01 Gbps-2Gbps-11-12-6-11-6-11-2 91Quality of 1010101010101010ServiceTransmission 25 to 50 ms250 ms100-150 ms25-75 mslatencySystem 93 to 99.5%99.98% (C-Ku band) 99.9% (C-Ku band)99.5% (L-C-Ku band)Availability w/o 99% (Ka band)99% (Ka band)99% (Ka band))BackupBroadcasting Low to NilHighLowLowCapabilitiesMulti-casting LowHighHighMediumCapabilitiesTrunking Very HighHighMediumLowCapabilitiesMobile ServicesNilMedium-to-HighHighHigh

34. VSAT Vs. Leased LineVSATFootprint across the countryHigh initial investment High reliability – Uptime of 99.5%No recurring b/w costsLeased LineOption not available in all areasLow initial investment Dependent on the capacity of the local systemRecurring Bandwidth costs

35. “Typical” Fixed Satellite NetworkApplications Credit Card Validation

36. ATM/Pay at the Pump

37. Inventory Control

38. Store Monitoring

39. Electronic Pricing

40. Training Videos

41. In-Store Audio

42. Broadband Internet Access

43. Distance LearningNetwork HUBApartment BuildingsInternetGas StationsCorporate Data Center/HQCorporate OfficesResidentialBranch OfficesSome large scale corporate networks have as many as 10,000 nodes

44. Satellite Network ConfigurationsVSAT

45. Satellite FrequenciesThere are specific frequency ranges used by commercial satellites.L-band (Mobile Satellite Services) 1.0 – 2.0 GHzS-band (MSS, DARS ) 1.55 – 3.9 GHzC-band (FSS, VSAT) 3.7 – 6.2 GHzX-Band (Military/Satellite Imagery) 8.0 – 12.0 GHzKu-band (FSS, DBS, VSAT) 11.7–14.5 GHzKa-band (FSS “broadband” and inter-satellite links) 17.7 - 21.2GHz and 27.5 – 31 GHz

46. VSAT TechnologyBands C-band (4-6 GHz), Ku-band (10-20 GHz) and Ka-band (20-30 GHz) that require different licensing approaches. Entities a) the Space Segment operator; b) the satellite network operator, who operates one or more Gateway Stations or Network Control Stations (HUBs) or other ground stations; c) the Satellite Service Provider; d) the subscriber who uses individual VSAT equipmentConnectivity – Point to Point (Mesh), Point to Multipoint (star, hub at centre), Multipoint to multipoint (hybrid)

47. Orbital OptionsA Geosynchronous satellite (GEO) completes one revolution around the world every 23 hrs and 56 minutes in order to maintain continuous positioning above the earth’s sub-satellite point on the equator. A medium earth orbit satellite (MEO) requires a constellation of 10 to 18 satellites in order to maintain constant coverage of the earth. A low earth orbit satellite (LEO) offers reduced signal loss since these satellites are 20 to 40 times closer to the earth in their orbits thus allowing for smaller user terminals/antennas.

48. Geostationary Orbit (GEO)Characteristics of Geostationary (GEO) Orbit SystemsUser terminals do not have to track the satellite

49. Only a few satellites can provide global coverage

50. Maximum life-time (15 years or more)

51. Above Van Allen Belt Radiation

52. Often the lowest cost system and simplest in terms of tracking and high speed switchingChallenges of Geostationary (GEO) OrbitTransmission latency or delay of 250 millisecond to complete up/down link

53. Satellite antennas must be of larger aperture size to concentrate power and to create narrower beams for frequency reuse

54. Poor look angle elevations at higher latitudesGeostationary Orbit Today

55. Low Earth Orbit (LEO)Characteristics of Low-Earth Orbit (LEO) Systems - Low latency or transmission delay - Higher look angle (especially in high-latitude regions) - Less path loss or beam spreading - Easier to achieve high levels of frequency re-use - Easier to operate to low-power/low-gain ground antennasChallenges of Low-Earth Orbit (LEO) Systems - Larger number of satellites (50 to 70 satellites). Thus higher launch costs to deploy, build, and operate. - Harder to deploy, track and operate. There is higher TTC&M costs even with cross links. - Shorter in-orbit lifetime due to orbital degradation

56. Medium Earth Orbit (MEO)Characteristics of Medium-Earth Orbit (MEO) Systems Less latency and delay than GEO (but greater than LEO)

57. Improved look angle to ground receivers in higher latitudes

58. Fewer satellites to deploy and operate and cheaper TTC&M systems than LEO (but more expensive than with GEO)

59. Longer in-orbit lifetime than LEO systems (but less than GEO)Challenges of Medium-Earth Orbit (MEO) SystemsMore satellites to deploy than GEO (10 to 18 vs. 3 to 4)

60. Ground antennas are generally more expensive and complex because of the need to track satellites. Or, one must use lower-gain, complex antennas.

61. Increased exposure to Van Allen Belt radiationTranspondersThe transponder is the “brain” of the satellite - provides the connection between the satellite’s receive and transmit antennas.

62. Satellites can have 12 to 96 transponders plus spares, depending on the size of the satellite.

63. A transponder bandwidth can frequently be 36 MHz, 54 MHz, or 72 MHz or it can be even wider.

64. A transponders function is to

65. Receive the signal, (Signal is one trillion times weaker then when transmitted)

66. Filter out noise,