1. CHAPTER 12: SATELLITE ATM NETWORKS I. F. Akyildiz Broadband & Wireless Networking Laboratory School of Electrical and Computer Engineering Georgia Institute of Technology Tel: 404-894-5141; Fax: 404-894-7883 Email: ian@ece.gatech.edu Web: http://www.ece.gatech.edu/research/labs/bwn

2. IFA’2005 ECE6609 2 Why Satellite ATM Networks ? Wide geographical area coverage From kbps to Gbps communication everywhere Faster deployment than terrestrial infrastructures Bypass clogged terrestrial networks and are oblivious to terrestrial disasters Supporting both symmetrical and asymmetrical architectures Seamless integration capability with terrestrial networks Very flexible bandwidth-on-demand capabilities Flexible in terms of network configuration and capacity allocation Broadcast, Point-to-Point and Multicast capabilities Scalable

3. IFA’2005 ECE6609 3Orbits Defining the altitude where the satellite will operate. Defining the altitude where the satellite will operate. Determining the right orbit depends on proposed service characteristics such as coverage, applications, delay. Determining the right orbit depends on proposed service characteristics such as coverage, applications, delay.

4. IFA’2005 ECE6609 4 Orbits (cont.)  Outer Van Allen Belt (13000-20000 km) MEO ( < 13K km) GEO (33786 km) LEO ( < 2K km) Inner Van Allen Belt (1500-5000 km) GEO: Geosynchronous Earth Orbit MEO: Medium Earth Orbit LEO: Low Earth Orbit

5. IFA’2005 ECE6609 5 Types of Satellites HEO: var. (Molniya, Ellipso) LEO: < 2K km MEO: < 13K km (Odyssey, Inmarsat-P) GEO: 33786 km (Globalstar, Iridium, Teledesic) Geostationary/Geosynchronous Earth Orbit Satellites (GSOs) (Propagation Delay: 250-280 ms) Geostationary/Geosynchronous Earth Orbit Satellites (GSOs) (Propagation Delay: 250-280 ms) Medium Earth Orbit Satellites (MEOs) (Propagation Delay: 110-130 ms) Medium Earth Orbit Satellites (MEOs) (Propagation Delay: 110-130 ms) Highly Elliptical Satellites (HEOs) (Propagation Delay: Variable) Highly Elliptical Satellites (HEOs) (Propagation Delay: Variable) Low Earth Orbit Satellite (LEOs) (Propagation Delay: 20-25 ms) Low Earth Orbit Satellite (LEOs) (Propagation Delay: 20-25 ms)

6. IFA’2005 ECE6609 6 Geostationary/Geosynchronous Earth Orbit Satellites (GSOs) 33786 km equatorial orbit 33786 km equatorial orbit Rotation speed equals Earth rotation speed (Satellite seems fixed in the horizon) Rotation speed equals Earth rotation speed (Satellite seems fixed in the horizon) Wide coverage area Wide coverage area Applications (Broadcast/Fixed Satellites, Direct Broadcast, Mobile Services) Applications (Broadcast/Fixed Satellites, Direct Broadcast, Mobile Services)

7. IFA’2005 ECE6609 7 Advantages of GSOs Wide coverage Wide coverage High quality and Wideband communications High quality and Wideband communications Economic Efficiency Economic Efficiency Tracking process is easier because of its synchronization to Earth Tracking process is easier because of its synchronization to Earth

8. IFA’2005 ECE6609 8 Disadvantages of GSOs Disadvantages of GSOs Long propagation delays (250-280 ms). (e.g., Typical Intern. Tel. Call  540 ms round-trip delay. Echo cancelers needed. Expensive!) (e.g., Delay may cause errors in data; Error correction /detection techniques are needed.) Long propagation delays (250-280 ms). (e.g., Typical Intern. Tel. Call  540 ms round-trip delay. Echo cancelers needed. Expensive!) (e.g., Delay may cause errors in data; Error correction /detection techniques are needed.) Large propagation loss. Requirement for high power level. (e.g., Future hand-held mobile terminals have limited power supply.) Currently: smallest terminal for a GSO is as large as an A4 paper and as heavy as 2.5 Kg. Large propagation loss. Requirement for high power level. (e.g., Future hand-held mobile terminals have limited power supply.) Currently: smallest terminal for a GSO is as large as an A4 paper and as heavy as 2.5 Kg.

9. IFA’2005 ECE6609 9 Disadvantages of GSOs (cont.) Lack of coverage at Northern and Southern latitudes. Lack of coverage at Northern and Southern latitudes. High cost of launching a satellite. High cost of launching a satellite. Enough spacing between the satellites to avoid collisions. Enough spacing between the satellites to avoid collisions. Existence of hundreds of GSOs belonging to different countries. Existence of hundreds of GSOs belonging to different countries. Available frequency spectrum assigned to GSOs is limited. Available frequency spectrum assigned to GSOs is limited.

10. IFA’2005 ECE6609 10 Medium Earth Orbit Satellites (MEOs) Positioned in 10-13K km range. Positioned in 10-13K km range. Delay is 110-130 ms. Delay is 110-130 ms. Will orbit the Earth at less than 1 km/s. Will orbit the Earth at less than 1 km/s. Applications Applications –Mobile Services/Voice (Intermediate Circular Orbit (ICO) Project) –Fixed Multimedia (Expressway)

11. IFA’2005 ECE6609 11 Highly Elliptical Orbit Satellites (HEOs) From a few hundreds of km to 10s of thousands  allows to maximize the coverage of specific Earth regions. 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. Variable field of view and delay. Examples: MOLNIYA, ARCHIMEDES (Direct Audio Broadcast), ELLIPSO. Examples: MOLNIYA, ARCHIMEDES (Direct Audio Broadcast), ELLIPSO.

12. IFA’2005 ECE6609 12 Low Earth Orbit Satellites (LEOs) Usually less than 2000 km (780-1400 km are favored). Usually less than 2000 km (780-1400 km are favored). Few ms of delay (20-25 ms). Few ms of delay (20-25 ms). They must move quickly to avoid falling into Earth  LEOs circle Earth in 100 minutes at 24K km/hour. (5-10 km per second). They must move quickly to avoid falling into Earth  LEOs circle Earth in 100 minutes at 24K km/hour. (5-10 km per second). Examples: Examples: –Earth resource management (Landsat, Spot, Radarsat) –Paging (Orbcomm) –Mobile (Iridium) –Fixed broadband (Teledesic, Celestri, Skybridge)

13. IFA’2005 ECE6609 13 Low Earth Orbit Satellites (LEOs) (cont.) Little LEOs: 800 MHz range Big LEOs: > 2 GHz Mega LEOs: 20-30 GHz

14. IFA’2005 ECE6609 14 Comparison of Different Satellite Systems

15. IFA’2005 ECE6609 15 Comparison of Satellite Systems According to their Altitudes (cont.)

16. IFA’2005 ECE6609 16 Why Hybrids? GSO + LEO GSO + LEO –GSO for broadcast and management information –LEO for real-time, interactive LEO or GSO + Terrestrial Infrastructure LEO or GSO + Terrestrial Infrastructure –Take advantage of the ground infrastructure

17. IFA’2005 ECE6609 17 Frequency Bands Frequency Bands NarrowBand Systems L-Band  1.535-1.56 GHz DL; 1.635-1.66 GHz UL L-Band  1.535-1.56 GHz DL; 1.635-1.66 GHz UL S-Band  2.5-2.54 GHz DL; 2.65-2.69 GHz UL S-Band  2.5-2.54 GHz DL; 2.65-2.69 GHz UL C-Band  3.7-4.2 GHz DL; 5.9-6.4 GHz UL C-Band  3.7-4.2 GHz DL; 5.9-6.4 GHz UL X-Band  7.25-7.75 GHz DL; 7.9-8.4 GHz UL X-Band  7.25-7.75 GHz DL; 7.9-8.4 GHz UL

18. IFA’2005 ECE6609 18 Frequency Bands (cont.) WideBand/Broadband Systems Ku-Band  10-13 GHz DL; 14-17 GHz UL (36 MHz of channel bandwidth; enough for typical 50-60 Mbps applications) Ku-Band  10-13 GHz DL; 14-17 GHz UL (36 MHz of channel bandwidth; enough for typical 50-60 Mbps applications) Ka-Band  18-20 GHz DL; 27-31 GHz UL (500 MHz of channel bandwidth; enough for Gigabit applications) Ka-Band  18-20 GHz DL; 27-31 GHz UL (500 MHz of channel bandwidth; enough for Gigabit applications)

19. IFA’2005 ECE6609 19 Next Generation Systems: Mostly Ka-band Ka band usage driven by: Ka band usage driven by: –Higher bit rates - 2Mbps to 155 Mbps –Lack of existing slots in the Ku band Features Features –Spot beams and smaller terminals –Switching capabilities on certain systems –Bandwidth-on-demand Drawbacks Drawbacks –Higher fading –Manufacturing and availability of Ka band devices –Little heritage from existing systems (except ACTS and Italsat)

20. IFA’2005 ECE6609 20 Frequency Bands (cont.) New Open Bands (not licensed yet) GHz of bandwidth GHz of bandwidth Q-Band  in the 40 GHz Q-Band  in the 40 GHz V-Band  60 GHz DL; 50 GHz UL V-Band  60 GHz DL; 50 GHz UL

21. IFA’2005 ECE6609 21 Space Environment Issues Harsh  hard on materials and electronics (faster aging) Harsh  hard on materials and electronics (faster aging) Radiation is high (Solar flares and other solar events; Van Allen Belts) Radiation is high (Solar flares and other solar events; Van Allen Belts) Reduction of lifes of space systems (12-15 years maximum). Reduction of lifes of space systems (12-15 years maximum).

22. IFA’2005 ECE6609 22 Space Environment Issues (cont.) Debris (specially for LEO systems) (At 7 Km/s impact damage can be important. Debris is going to be regulated). Debris (specially for LEO systems) (At 7 Km/s impact damage can be important. Debris is going to be regulated). Atomic oxygen can be a threat to materials and electronics at LEO orbits. Atomic oxygen can be a threat to materials and electronics at LEO orbits. Gravitation pulls the satellite towards earth. Gravitation pulls the satellite towards earth. Limited propulsion to maintain orbit (Limits the life of satellites; Drags an issue for LEOs). Limited propulsion to maintain orbit (Limits the life of satellites; Drags an issue for LEOs). Thermal Environment again limits material and electronics life. Thermal Environment again limits material and electronics life.

23. IFA’2005 ECE6609 23 Basic Architecture Ring Wireless Terrestrial Network Internet LAN Ethernet Internet Ethernet Ring Mobile Network Public Network MAN SIU- Satellite Interface Unit SIU - Satellite Interworking Unit

24. IFA’2005 ECE6609 24 ATM-Satellite Configuration Multi-Service Workstation ASIU Modem SONET/ PDH/PLCP Satellite Interface Multi-Service Workstation ASIU Modem SONET/ PDH/PLCP Satellite Interface Satellite

25. IFA’2005 ECE6609 25 3.2. ATM Satellite Interworking Unit (ASIU)

26. IFA’2005 ECE6609 26 Payload Concepts Bent Pipe Processing Bent Pipe Processing Onboard Processing Onboard Processing Onboard Switching Onboard Switching

27. IFA’2005 ECE6609 27 Bent Pipe Processing Amplifies (repeats) the received signals Amplifies (repeats) the received signals Does not require demodulation/modulation of signals Does not require demodulation/modulation of signals Simple payload (but little flexibility) Simple payload (but little flexibility)

28. IFA’2005 ECE6609 28 Bent-Pipe Protocol Stack (IP over ATM) Physical Satellite TCP AAL ATM Medium Access Control Data Link Control Physical User Terminal Applications UDP IP TCP AAL ATM Medium Access Control Data Link Control Physical User Terminal Applications UDP IP

29. IFA’2005 ECE6609 29 3.5 Onboard Processing (Transparent) Regenerates the received frequencies (3 dB gain) Regenerates the received frequencies (3 dB gain) Requires demodulation/modulation of signals Requires demodulation/modulation of signals Digital payload (can be multibeam) Digital payload (can be multibeam) Used mostly for mobile systems Used mostly for mobile systems

30. IFA’2005 ECE6609 30 Onboard Processing Protocol Stack (IP over ATM) Satellite TCP AAL ATM Medium Access Control Data Link Control Physical User Terminal Applications UDP IP TCP AAL ATM Medium Access Control Data Link Control Physical User Terminal Applications UDP IP Physical Medium Access Control Data Link Control

31. IFA’2005 ECE6609 31 Onboard Switching Regenerates the received frequencies (3 dB gain) Regenerates the received frequencies (3 dB gain) Digital baseband switching multibeam payload Digital baseband switching multibeam payload Baseline for most future satellite systems Baseline for most future satellite systems

32. IFA’2005 ECE6609 32 Onboard Switching Protocol Stack (IP over ATM) TCP AAL ATM Medium Access Control Data Link Control Physical User Terminal Applications UDP IP TCP AAL ATM Medium Access Control Data Link Control Physical User Terminal Applications UDP IP Satellite Physical Medium Access Control Data Link Control Network

33. IFA’2005 ECE6609 33 ATM Network AIU TIU FIU MIU LMAPC ACDU ACMU ACDU ACMU Existing ASIU Functions Existing ASIU Functions SIU EIU Token Ring Ethernet FDDI IEEE 802.6 MAN LAN/MAN Interconnection ATM Network AIU TIU FIU MIU LMAPC ACDU ACMU ACDU ACMU Existing ASIU Functions Existing ASIU Functions SIU EIU Token Ring Ethernet FDDI IEEE 802.6 MAN ASIU Satellite Modem Communication Satellite

34. IFA’2005 ECE6609 34 Physical MAC. (IEEE 802 3,5,6 LLC IP TCP/UDP Applicat- ions & Higher Layers Physical MAC (IEEE 802.3,5,6 LLC LMAPC Satellite Modem I/F AAL ATM Physical USER Physical MAC (IEEE 802.3,5,6 LLC IP TCP/ UDP Applications & Higher Layers Physical MAC (IEEE 802.3,5,6 LLC LMAPC Satellite Modem I/F AAL ATM Physical USER LAN/MAN Internetworking Protocol Architecture Communication Satellite 1 2a 2b 3 4 ASIU Satellite Modem

35. IFA’2005 ECE6609 35 IP-ATM-Satellite Configuration TCP-PEACH RTCP/UDP Applications Quality-Critical Time-Critical IPv4/IPv6 AAL5AAL2x Physical MAC (WISPER-2) AFEC ATM RCS A NEW PROTOCOL SUITE FOR SATELLITE NETWORKS

36. IFA’2005 ECE6609 36 TCP Problems in Satellite Networks Long Propagation Delays Long Propagation Delays - Long duration of the Slow Start phase -> TCP sender does not use the available bandwidth - cwnd < rwnd. The transmission rate of the sender is bounded. The higher RTT the lower is the bound on the transmission rate for the sender. The transmission rate of the sender is bounded. The higher RTT the lower is the bound on the transmission rate for the sender.

37. IFA’2005 ECE6609 37 TCP Problems in Satellite Networks High link error rates High link error rates - The TCP protocol was initially designed to work in networks with low link error rates, i.e., all segment losses were mostly due to network congestion. As a result the TCP sender decreases its transmission rate -> causes unnecessary throughput degradation if segment losses occur due to link errors

38. IFA’2005 ECE6609 38 TCP Problems in Satellite Networks Asymmetric Bandwidth: Asymmetric Bandwidth: - ACK packets may congest the reverse channel, and be delayed or lost -> Traffic burstiness increases and Throughput decreases

39. IFA’2005 ECE6609 39 Duration of the Slow Start for LEO, MEO and GEO Satellites Satellite Type RTT msec TSlowStart (B=1Mb/sec) TSlowStart (B=10Mb/sec) TSlowStart (B=155Mb/sec) LEO500.18 sec0.35 sec0.55 sec MEO2501.49 sec2.32 sec3.31 sec GEO5503.91 sec5.73 sec7.91 sec

40. IFA’2005 ECE6609 40 TCP Peach: A New Congestion Scheme for Satellite Networks Sudden Start (*) Sudden Start (*) Congestion Avoidance Congestion Avoidance Fast Retransmit Fast Retransmit Rapid Recovery (*) Rapid Recovery (*) * I. F. Akyildiz, G. Morabito, S. Palazzo,”TCP Peach: A New Flow Control Scheme for Satellite Networks”. IEEE/ACM Transactions on Networking, June 2001.

41. IFA’2005 ECE6609 41 TCP-Peach Scheme

42. IFA’2005 ECE6609 42 Comparison Between the Sudden Start and the Slow Start

43. IFA’2005 ECE6609 43 What is Handover? Leo Satellites circulate the Earth at a constant speed. Leo Satellites circulate the Earth at a constant speed. Coverage area of a LEO satellite changes continuously. Coverage area of a LEO satellite changes continuously. Handover is necessary between end-satellites. Handover is necessary between end-satellites.

44. IFA’2005 ECE6609 44 Types of Handover Types of Handover

45. IFA’2005 ECE6609 45 Footprint and Orbit Periods

46. IFA’2005 ECE6609 46 Handover Management Through Re-routing Uzunalioglu, H., Akyildiz, I.F., Yesha, Y., and Yen W., "Footprint Handover Rerouting Protocol for LEO Satellite Networks," ACM-Baltzer Journal of Wireless Networks (WINET), Vol. 5, No. 5, pp. 327-337, November 1999. Handover Management Through Re-routing Uzunalioglu, H., Akyildiz, I.F., Yesha, Y., and Yen W., "Footprint Handover Rerouting Protocol for LEO Satellite Networks," ACM-Baltzer Journal of Wireless Networks (WINET), Vol. 5, No. 5, pp. 327-337, November 1999.

47. IFA’2005 ECE6609 47 Footprint Re-routing (FR) Footprint Re-routing (FR)

48. IFA’2005 ECE6609 48 Routing Algorithms for Satellite Networks Satellites organized in planes Satellites organized in planes User Data Links (UDL) User Data Links (UDL) Inter-Satellite Links (ISL) Inter-Satellite Links (ISL) Short roundtrip delays Short roundtrip delays Very dynamic yet predictable network topology Very dynamic yet predictable network topology –Satellite positions –Link availability Changing visibility from the Earth Changing visibility from the Earth http://www.teledesic.com/tech/mGall.htm

49. IFA’2005 ECE6609 49 Seam Seam –Border between counter-rotating satellite planes Polar Regions Polar Regions –Regions where the inter-plane ISLs are turned off LEO’s at Polar Orbits n E. Ekici, I. F. Akyildiz, M. Bender, “The Datagram Routing Algorithm for Satellite IP Networks”, IEEE/ACM Transactions on Networking, April 2001. n E. Ekici, I. F. Akyildiz, M. Bender, “A New Multicast Routing Algorithm for Satellite IP Networks”, IEEE/ACM Transactions on Networking, April 2002.

50. IFA’2005 ECE6609 50 IP-Based Routing in LEO Satellite Networks Datagram Routing Datagram Routing –Darting Algorithm –Geographic- Based Multicast Routing Multicast Routing –No scheme available

51. IFA’2005 ECE6609 51 Routing in Multi-Layered Satellite Networks

52. IFA’2005 ECE6609 52 Satellite Architecture Satellite Architecture –Consists of multiple layers (here 3) –UDL/ISL/IOL –Terrestrial gateways connected to at least one satellite Multi-Layered Satellite Routing I.F. Akyildiz, E. Ekici and M.D. Bender, “MLSR: A Novel Routing Algorithm for Multi- Layered Satellite IP Networks,” IEEE/ACM Transactions on Networking, June 2002.

53. IFA’2005 ECE6609 53 Iridium Network

54. IFA’2005 ECE6609 54 Iridium Network (cont.)

55. IFA’2005 ECE6609 55 Iridium Network (cont.) 6 orbits 6 orbits 11 satellites/orbit 11 satellites/orbit 48 spotbeams/satellite 48 spotbeams/satellite Spotbeam diameter = 700 km Spotbeam diameter = 700 km Footprint diameter = 4021km Footprint diameter = 4021km 59 beams to cover United States 59 beams to cover United States Satellite speed = 26,000 km/h = 7 km/s Satellite speed = 26,000 km/h = 7 km/s Satellite visibility = 9 - 10 min Satellite visibility = 9 - 10 min Spotbeam visibility < 1 minute Spotbeam visibility < 1 minute System period = 100 minutes System period = 100 minutes

56. IFA’2005 ECE6609 56 Iridium Network (cont.) 4.8 kbps voice, 2.4 Kbps data 4.8 kbps voice, 2.4 Kbps data TDMA TDMA 80 channels /beam 80 channels /beam 3168 beams globally (2150 active beams) 3168 beams globally (2150 active beams) Dual mode user handset Dual mode user handset User-Satellite Link = L-Band User-Satellite Link = L-Band Gateway-Satellite Link = Ka-Band Gateway-Satellite Link = Ka-Band Inter-Satellite Link = Ka-Band Inter-Satellite Link = Ka-Band

57. IFA’2005 ECE6609 57 Operational Systems

58. IFA’2005 ECE6609 58 Operational Systems (cont.) Little LEOs

59. IFA’2005 ECE6609 59 Proposed and Operational Systems 1.ICO Global Communications (New ICO) nNumber of Satellites:10 nPlanes:2 nSatellites/Plane:5 nAltitude:10,350 km nOrbital Inclination:45° nRemarks: Service: Voice @ 4.8 kbps, data @ 2.4 kbps and higher Service: Voice @ 4.8 kbps, data @ 2.4 kbps and higher Operation anticipated in 2003 Operation anticipated in 2003 System taken over by private investors due to financial difficulties System taken over by private investors due to financial difficulties Estimated cost: $4,000,000,000 Estimated cost: $4,000,000,000 163 spot beams/satellite, 950,000 km 2 coverage area/beam, 28 channels/beam 163 spot beams/satellite, 950,000 km 2 coverage area/beam, 28 channels/beam Service link:1.98-2.01 GHz (downlink), 2.17-2.2 GHz (uplink); (TDMA) Service link:1.98-2.01 GHz (downlink), 2.17-2.2 GHz (uplink); (TDMA) Feeder link: 3.6 GHz band (downlink), 6.5 GHz band (uplink) Feeder link: 3.6 GHz band (downlink), 6.5 GHz band (uplink)

60. IFA’2005 ECE6609 60 Proposed and Operational Systems (cont.) 2.Globalstar nNumber of Satellites: 48 nPlanes:8 nSatellites/Plane:6 nAltitude: 1,414 km nOrbital Inclination: 52° nRemarks: Service: Voice @ 4.8 kbps, data @ 7.2 kbps Service: Voice @ 4.8 kbps, data @ 7.2 kbps Operation started in 1999 Operation started in 1999 Early financial difficulties Early financial difficulties Estimated cost: $2,600,000,000 Estimated cost: $2,600,000,000 16 spot beams/satellite, 2,900,000 km 2 coverage area/beam, 175 channels/beam 16 spot beams/satellite, 2,900,000 km 2 coverage area/beam, 175 channels/beam Service link:1.61-1.63 GHz (downlink), 2.48-2.5 GHz (uplink); (CDMA) Service link:1.61-1.63 GHz (downlink), 2.48-2.5 GHz (uplink); (CDMA) Feeder link: 6.7-7.08 GHz (downlink), 5.09-5.25 GHz (uplink) Feeder link: 6.7-7.08 GHz (downlink), 5.09-5.25 GHz (uplink)

61. IFA’2005 ECE6609 61 Proposed and Operational Systems (cont.) 3.ORBCOM nNumber of Satellites:36 nPlanes:42 nSatellites/Plane:22 nAltitude:775 km775 km nOrbital Inclination:45° 70° nRemarks: Near real-time service Near real-time service Operation started in 1998 (first in market) Operation started in 1998 (first in market) Cost: $350,000,000 Cost: $350,000,000 Service link:137-138 MHz (downlink), 148-149 MHz (uplink) Service link:137-138 MHz (downlink), 148-149 MHz (uplink) Spacecraft mass: 40 kg Spacecraft mass: 40 kg

62. IFA’2005 ECE6609 62 Proposed and Operational Systems (cont.) 4.Starsys nNumber of Satellites:24 nPlanes: 6 nSatellites/Plane: 4 nAltitude:1,000 km nOrbital Inclination:53° nRemarks: Service: Messaging and positioning Service: Messaging and positioning Global coverage Global coverage Service link:137-138 MHz (downlink), 148-149 MHz (uplink) Service link:137-138 MHz (downlink), 148-149 MHz (uplink) Spacecraft mass: 150 kg Spacecraft mass: 150 kg

63. IFA’2005 ECE6609 63 Proposed and Operational Systems (cont.) 5.Teledesic (original proposal) nNumber of Satellites: 840 (original) nPlanes: 21 nSatellites/Plane: 40 nAltitude:700 km nOrbital Inclination:98.2° nRemarks: Service: FSS, provision for mobile service (16 kbps – 2.048 Mbps, including video) for 2,000,000 users Service: FSS, provision for mobile service (16 kbps – 2.048 Mbps, including video) for 2,000,000 users Sun-synchronous orbit, earth-fixed cells Sun-synchronous orbit, earth-fixed cells System cost: $9,000,000,000 ($2000 for terminals) System cost: $9,000,000,000 ($2000 for terminals) Service link:18.8-19.3 GHz (downlink), 28.6-29.1 GHz (uplink) (K a band) Service link:18.8-19.3 GHz (downlink), 28.6-29.1 GHz (uplink) (K a band) ISL: 60 GHz ISL: 60 GHz Spacecraft mass: 795 kg Spacecraft mass: 795 kg

64. IFA’2005 ECE6609 64 Proposed and Operational Systems (cont.) 6.Teledesic (final proposal) nNumber of Satellites:288 (scaled down) nPlanes: 12 nSatellites/Plane: 24 nAltitude:700 km nRemarks: Service: FSS, provision for mobile service (16 kbps – 2.048 Mbps, including video) for 2,000,000 users Service: FSS, provision for mobile service (16 kbps – 2.048 Mbps, including video) for 2,000,000 users Sun-synchronous orbit, earth-fixed cells Sun-synchronous orbit, earth-fixed cells System cost: $9,000,000,000 ($2000 for terminals) System cost: $9,000,000,000 ($2000 for terminals) Service link:18.8-19.3 GHz (downlink), 28.6-29.1 GHz (uplink) (K a band) Service link:18.8-19.3 GHz (downlink), 28.6-29.1 GHz (uplink) (K a band) ISL: 60 GHz ISL: 60 GHz Spacecraft mass: 795 kg Spacecraft mass: 795 kg

65. IFA’2005 ECE6609 65 HALO TM Network : A Wireless Broadband Metropolitan Area Network Frequency Options - 28 or 38 GHz Service Availability Urban Area Suburban & Rural Areas Areas 50 - 75 miles 1 to 15 HALO TM Gateway Beams 100 to 1000 Subscriber Beams Coverage Cells 15 - 150 Gbps Throughput Capacity (5,000 to 50,000 T1 Equivalents) To Satellites

66. IFA’2005 ECE6609 66 HALO TM Network (cont.) Business Premise Equipment HALO™ Network Hub Internet Service Provider (ISP), Content Producer Public Switched Telephone Network (PSTN) To Remote Metropolitan Centers BPE CPE Communication Payload (Payload & Switching Node) Network Operations Center Consumer Premise Equipment HALO Gateway

67. IFA’2005 ECE6609 67 HALO TM Network (cont.): Mobility Model

68. IFA’2005 ECE6609 68 A Stratospheric Communications Layer GEO Satellites 22,300 miles LEO Satellites 400 miles Terrestrial < 200 ft High Altitude Long Operation HALO Aircraft 10 miles

69. IFA’2005 ECE6609 69 Interconnection of HALO TM Networks 100 Sites Serve 72% of Population

70. IFA’2005 ECE6609 70 References Published in BWN Lab (http://www.ece.gatech.edu/research/labs/bwn/ ) 1.Survey Paper Akyildiz, I.F. and Jeong, S., "Satellite ATM Networks: A Survey," IEEE Communications Magazine, Vol. 35, No. 7, pp.30-44, July 1997.Akyildiz, I.F. and Jeong, S., "Satellite ATM Networks: A Survey," IEEE Communications Magazine, Vol. 35, No. 7, pp.30-44, July 1997.

71. IFA’2005 ECE6609 71 References Published in BWN Lab (http://www.ece.gatech.edu/research/labs/bwn/ ) 2. Transport Layer Akyildiz, I.F., Morabito, G., and Palazzo, S., "TCP Peach for Satellite Networks: Analytical Model and Performance Evaluation,'' International Journal of Satellite Communications, Vol. 19, pp. 429- 442, October 2001.Akyildiz, I.F., Morabito, G., and Palazzo, S., "TCP Peach for Satellite Networks: Analytical Model and Performance Evaluation,'' International Journal of Satellite Communications, Vol. 19, pp. 429- 442, October 2001. Akyildiz, I.F., Morabito, G., Palazzo, S., "TCP Peach: A New Congestion Control Scheme for Satellite IP Networks,'' IEEE/ACM Transactions on Networking, Vol. 9, No. 3, June 2001.Akyildiz, I.F., Morabito, G., Palazzo, S., "TCP Peach: A New Congestion Control Scheme for Satellite IP Networks,'' IEEE/ACM Transactions on Networking, Vol. 9, No. 3, June 2001. Akyildiz, I.F., Morabito, G., Palazzo, S., “Research Issues for Transport Protocols in Satellite IP Networks,'' IEEE PCS (Personal Communications Systems) Magazine, Vol. 8, No. 3, pp. 44-48, June 2001.Akyildiz, I.F., Morabito, G., Palazzo, S., “Research Issues for Transport Protocols in Satellite IP Networks,'' IEEE PCS (Personal Communications Systems) Magazine, Vol. 8, No. 3, pp. 44-48, June 2001. Morabito, G., Tang, J., Akyildiz, I.F., and Johnson, M., “A New Rate Control Scheme for Real-Time Traffic in Satellite IP Networks,'' IEEE Infocom'01, April 2001, Alaska.Morabito, G., Tang, J., Akyildiz, I.F., and Johnson, M., “A New Rate Control Scheme for Real-Time Traffic in Satellite IP Networks,'' IEEE Infocom'01, April 2001, Alaska.

72. IFA’2005 ECE6609 72 References Published in BWN Lab (http://www.ece.gatech.edu/research/labs/bwn/ ) 2. Transport Layer (cont.) Morabito, G., Akyildiz, I.F., Palazzo S., "Design and Modeling of a New Flow Control Scheme (TCP Peach) for Satellite Networks" IFIP-TC6/ European Union: Networking 2000 Conference: Broadband Satellite Workshop, Paris, France, May 2000.Morabito, G., Akyildiz, I.F., Palazzo S., "Design and Modeling of a New Flow Control Scheme (TCP Peach) for Satellite Networks" IFIP-TC6/ European Union: Networking 2000 Conference: Broadband Satellite Workshop, Paris, France, May 2000. Morabito G., Akyildiz, I.F., Palazzo, S., "ABR Traffic Control for Satellite ATM Networks," IEEE Globecom'99 Conference, Rio De Janeiro, December 1999.Morabito G., Akyildiz, I.F., Palazzo, S., "ABR Traffic Control for Satellite ATM Networks," IEEE Globecom'99 Conference, Rio De Janeiro, December 1999. 3.Handover Management Cho, S., Akyildiz I. F., Bender M. D., and Uzunalioglu H., "A New Connection Admission Control for Spotbeam Handover in LEO Satellite Networks," to appear in ACM-Kluwer Wireless Networks Journal, 2002.Cho, S., Akyildiz I. F., Bender M. D., and Uzunalioglu H., "A New Connection Admission Control for Spotbeam Handover in LEO Satellite Networks," to appear in ACM-Kluwer Wireless Networks Journal, 2002. Cho, S.R., Akyildiz, I.F., Bender, M.D., and Uzunalioglu, H., “A New Spotbeam Handover Management Technique for LEO Satellite Networks,'' Proc. of IEEE GLOBECOM 2000, San Francisco, CA, November 2000.Cho, S.R., Akyildiz, I.F., Bender, M.D., and Uzunalioglu, H., “A New Spotbeam Handover Management Technique for LEO Satellite Networks,'' Proc. of IEEE GLOBECOM 2000, San Francisco, CA, November 2000.

73. IFA’2005 ECE6609 73 References Published in BWN Lab (http://www.ece.gatech.edu/research/labs/bwn/ ) 3. Handover Management (cont.) Cho, S., “Adaptive Dynamic Channel Allocation Scheme for Spotbeam Handover in LEO Satellite Networks,'' to appear in the IEEE Vehicular Technology Conference (IEEE VTC) 2000, Boston, MA, September, 2000.Cho, S., “Adaptive Dynamic Channel Allocation Scheme for Spotbeam Handover in LEO Satellite Networks,'' to appear in the IEEE Vehicular Technology Conference (IEEE VTC) 2000, Boston, MA, September, 2000. McNair, J., “Location Registration in Mobile Satellite Systems'', Proc. of the 5th IEEE Symposium on Computers and Communications (ISCC 2000), July 2000.McNair, J., “Location Registration in Mobile Satellite Systems'', Proc. of the 5th IEEE Symposium on Computers and Communications (ISCC 2000), July 2000. Akyildiz, I.F., Uzunalioglu, H., and Bender, M.D., "Handover Management in Low Earth Orbit (LEO) Satellite Networks," ACM- Baltzer Journal of Mobile Networks and Applications (MONET), Vol. 4, No. 4, pp. 301-310, December 1999.Akyildiz, I.F., Uzunalioglu, H., and Bender, M.D., "Handover Management in Low Earth Orbit (LEO) Satellite Networks," ACM- Baltzer Journal of Mobile Networks and Applications (MONET), Vol. 4, No. 4, pp. 301-310, December 1999. Uzunalioglu, H., Akyildiz, I.F., Yesha, Y., and Yen W., "Footprint Handover Rerouting Protocol for LEO Satellite Networks," ACM- Baltzer Journal of Wireless Networks (WINET), Vol. 5, No. 5, pp. 327- 337, November 1999.Uzunalioglu, H., Akyildiz, I.F., Yesha, Y., and Yen W., "Footprint Handover Rerouting Protocol for LEO Satellite Networks," ACM- Baltzer Journal of Wireless Networks (WINET), Vol. 5, No. 5, pp. 327- 337, November 1999.

74. IFA’2005 ECE6609 74 References Published in BWN Lab (http://www.ece.gatech.edu/research/labs/bwn/ ) 3. Handover Management (cont.) Uzunalioglu, H., Evans, J.W., and Gowens, J., ”A Connection Admission Control Algorithm for Low Earth Orbit (LEO) Satellite Networks,'' Proc. of IEEE ICC'99, pp. 1074 - 1078, Vancouver, Canada, June 1999.Uzunalioglu, H., Evans, J.W., and Gowens, J., ”A Connection Admission Control Algorithm for Low Earth Orbit (LEO) Satellite Networks,'' Proc. of IEEE ICC'99, pp. 1074 - 1078, Vancouver, Canada, June 1999. Uzunalioglu, H., and Yen W., “Managing Connection Handover in Satellite Networks,'' Proc. IEEE GLOBECOM '97, pp. 1606- 1610, Phoenix, Arizona, Dec. 1997.Uzunalioglu, H., and Yen W., “Managing Connection Handover in Satellite Networks,'' Proc. IEEE GLOBECOM '97, pp. 1606- 1610, Phoenix, Arizona, Dec. 1997. Uzunalioglu, H., Yen W., and Akyildiz, I.F., "Handover Management in LEO Satellite ATM Networks," Proc. of the ACM/IEEE MobiCom'97, pp. 204-214, October 1997.Uzunalioglu, H., Yen W., and Akyildiz, I.F., "Handover Management in LEO Satellite ATM Networks," Proc. of the ACM/IEEE MobiCom'97, pp. 204-214, October 1997.

75. IFA’2005 ECE6609 75 References Published in BWN Lab (http://www.ece.gatech.edu/research/labs/bwn/ ) 4. Routing Akyildiz, I.F., Ekici, E., and Bender, M.D., "MLSR: A Novel Routing Algorithm for Multi-Layered Satellite IP Networks", April 2001; Revised in September 2001.Akyildiz, I.F., Ekici, E., and Bender, M.D., "MLSR: A Novel Routing Algorithm for Multi-Layered Satellite IP Networks", April 2001; Revised in September 2001. Ekici, E., Akyildiz, I.F., and Bender, M., “A Multicast Routing Algorithm for LEO Satellite IP Networks,'' to appear in IEEE/ACM Transactions on Networking, April 2002.Ekici, E., Akyildiz, I.F., and Bender, M., “A Multicast Routing Algorithm for LEO Satellite IP Networks,'' to appear in IEEE/ACM Transactions on Networking, April 2002. Ekici, E., Akyildiz, I.F., Bender, M., "A Distributed Routing Algorithm for Datagram Traffic in LEO Satellite Networks," IEEE/ACM Transactions on Networking, Vol. 9, No. 2, pp. 137-148, April 2001.Ekici, E., Akyildiz, I.F., Bender, M., "A Distributed Routing Algorithm for Datagram Traffic in LEO Satellite Networks," IEEE/ACM Transactions on Networking, Vol. 9, No. 2, pp. 137-148, April 2001. Ekici, E., Akyildiz, I.F., and Bender, M.D., "Network Layer Integration of Terrestrial and Satellite IP Networks over BGP-S" Proceedings of GLOBECOM 2001, San Antonio, TX, Nov. 25-29, 2001.Ekici, E., Akyildiz, I.F., and Bender, M.D., "Network Layer Integration of Terrestrial and Satellite IP Networks over BGP-S" Proceedings of GLOBECOM 2001, San Antonio, TX, Nov. 25-29, 2001. Uzunalioglu, H., Akyildiz, I.F., and Bender, M.D., “A Routing Algorithm for LEO Satellite Networks with Dynamic Connectivity,'' ACM-Baltzer Journal of Wireless Networks (WINET), Vol. 6, No. 3, pp. 181-190, June 2000.Uzunalioglu, H., Akyildiz, I.F., and Bender, M.D., “A Routing Algorithm for LEO Satellite Networks with Dynamic Connectivity,'' ACM-Baltzer Journal of Wireless Networks (WINET), Vol. 6, No. 3, pp. 181-190, June 2000.

76. IFA’2005 ECE6609 76 References Published in BWN Lab (http://www.ece.gatech.edu/research/labs/bwn/ ) 4. Routing (cont.) Ekici, E., Akyildiz, I.F., Bender, M.D., "Datagram Routing Algorithm for LEO Satellite Networks'' IEEE INFOCOM'2000, Israel, March 2000.Ekici, E., Akyildiz, I.F., Bender, M.D., "Datagram Routing Algorithm for LEO Satellite Networks'' IEEE INFOCOM'2000, Israel, March 2000. Uzunalioglu, H., “Probabilistic Routing Protocol for Low Earth Orbit Satellite Networks,'' Proc. of the IEEE ICC'98, Atlanta, pp. 89-93, June 1998.Uzunalioglu, H., “Probabilistic Routing Protocol for Low Earth Orbit Satellite Networks,'' Proc. of the IEEE ICC'98, Atlanta, pp. 89-93, June 1998. 5.HALO Network Colella, N.J., Martin, J., and Akyildiz, I.F., "The HALO Network,'' IEEE Communications Magazine, Vol. 38, No. 6, pp. 142-148, June 2000.Colella, N.J., Martin, J., and Akyildiz, I.F., "The HALO Network,'' IEEE Communications Magazine, Vol. 38, No. 6, pp. 142-148, June 2000. Akyildiz, I.F., Wang, X., and Colella, N., "HALO (High Altitude Long Operation): A Broadband Wireless Metropolitan Area Network,'' IEEE MoMuC'99 (Mobile Multimedia Communication Conference), San Diego, November 1999.Akyildiz, I.F., Wang, X., and Colella, N., "HALO (High Altitude Long Operation): A Broadband Wireless Metropolitan Area Network,'' IEEE MoMuC'99 (Mobile Multimedia Communication Conference), San Diego, November 1999.