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Activities at AIT Activities at AIT (Asian Institute of Technology) (Asian Institute of Technology) by by Kanchana Kanchanasut Kanchana Kanchanasut AIT AIT AIT is an international education AIT is an international education institute


  1. Activities at AIT Activities at AIT (Asian Institute of Technology) (Asian Institute of Technology) by by Kanchana Kanchanasut Kanchana Kanchanasut AIT AIT

  2. AIT is an international education AIT is an international education institute institute

  3. Asian Institute of Technology Asian Institute of Technology • International Partnerships International Partnerships • • Regional Mission Regional Mission • • www. www.ait ait.ac. .ac.th th •

  4. AIT MISSION AIT MISSION Being a multinational institution of higher education devoted to human resources development in the region.

  5. AIT Alumni 1961- ����� ���������������������� ����� ���������������������� ������������������������������������������������������������������������������� ������������������������������������������������������������������������������� ������������������������������������ �������� ������������������������������������ �������� ��!�����������������������"�����������#��������� ��!�����������������������"�����������#��������� ���������"����������$��%��!�����&�$��% ��!����'����%�������(��)������ ���������"����������$��%��!�����&�$��% ��!����'����%�������(��)������ ������������������������*������+�������#���$���������� ������������������������*������+�������#���$����������

  6. Networking Research at AIT Networking Research at AIT • Computer Science Computer Science • • Telecommunications Telecommunications • • Internet Education and Research Lab Internet Education and Research Lab •

  7. intERLab@AIT @AIT intERLab • Research Lab Research Lab • • Activities Based Activities Based • • Three major components: Three major components: • – Internet Technology & Infrastructures Internet Technology & Infrastructures – – Internet Applications Internet Applications – – Social/Governance & Policy/Legal Study Social/Governance & Policy/Legal Study –

  8. Internet for Rural Community Internet for Rural Community QuickTime™ and a TIFF (Uncompressed) decompressor are needed to see this picture.

  9. Satellite Network Satellite Network • Pros Pros • – Broadcasting capabilities Broadcasting capabilities – – Large geographical coverage Large geographical coverage – • Cons Cons • – Long round trip delay (560 ms) Long round trip delay (560 ms) – – Burst error because of weather effect Burst error because of weather effect –

  10. Satellite Network Satellite Network • Bi Bi- -directional link directional link • – Costly Costly – – Complex setup, Complex setup, – – Operating license required Operating license required – • Uni Uni- -directional link directional link • – Easy to setup Easy to setup – – No license required No license required – – Any user can become a host just having a receiver Any user can become a host just having a receiver – antenna antenna

  11. Satellite UDL Characteristics Satellite UDL Characteristics • One One- -way communication channel way communication channel • • Wide area coverage Wide area coverage • • High bandwidth High bandwidth • • Long delay Long delay •

  12. Unidirectional satellite link Unidirectional satellite link Unidirectional Satellite Link Feed router Receiving routers UDL Receiving networks UDL feeding networks

  13. Unidirectional Link Routing Unidirectional Link Routing (UDLR) (UDLR) Unidirectional Satellite Link Feed router Receiving routers UDL Receiving networks UDL feeding networks Internet

  14. Multicasting Multicasting • Simultaneous delivery of packets from a Simultaneous delivery of packets from a • sender to a selected group of recipients sender to a selected group of recipients • Can dramatically reduce network bandwidth Can dramatically reduce network bandwidth • • Applications : Live Conferencing (Audio and Applications : Live Conferencing (Audio and • Video, Software Upgrade Distribution, White Video, Software Upgrade Distribution, White Board Collaboration Applications, Distributed Board Collaboration Applications, Distributed Databases. Databases.

  15. Reliable Multicast: Reliable Multicast: Bulk Data Transfer Bulk Data Transfer • Web Cache Web Cache • • Software Software • • Newspapers Newspapers •

  16. Reliable Multicast over Reliable Multicast over Unidirectional Satellite Unidirectional Satellite Link (UDLR) Link (UDLR) Patcharee Basu Patcharee Basu & & Kanchana Kanchanasut Kanchana Kanchanasut

  17. Unidirectional Link Routing Unidirectional Link Routing (UDLR) (UDLR) Unidirectional Satellite Link Feed router Receiving routers UDL Receiving networks UDL feeding networks Internet

  18. Reliable Multicast for Reliable Multicast for Unidirectional Satellite Link( Unidirectional Satellite Link( RMUS) RMUS) • Error Control Error Control • – Correct data loss and out Correct data loss and out- -of of- -order packet at end of order packet at end of – transmission transmission • Error detection Error detection – – NAK NAK- -based receiver based receiver- -initiated initiated • • Error recovery Error recovery – – Selective repeat Selective repeat • • Congestion Control Congestion Control • – Prevent data loss during transmission period Prevent data loss during transmission period – • Modification of Monitor Modification of Monitor- -Based Flow Control (MBFC) Based Flow Control (MBFC) • • Rate adjustment Rate adjustment •

  19. UDLR Scenario UDLR Scenario � � � � � � � � ������ �������� �������� �������� �������� �������� �������� ��� ���� ��� ��� ��� ��� ���� ���� �������������������� ��������������������

  20. UDLR Scenario UDLR Scenario R � � � � � � � � R R R R R R ������ �������� �������� �������� �������� �������� �������� ��� ���� ��� ��� ��� ��� ���� ���� �������������������� ��������������������

  21. Design Constraints Design Constraints • Application • Application – Reliability Reliability – – Not time – Not time- -sensitive sensitive • Satellite UDL • Satellite UDL – Downstream link Downstream link – • High bandwidth High bandwidth • • Long delay Long delay • – Return paths Return paths – • Receivers do not share the same return path Receivers do not share the same return path • • As good as the worst one As good as the worst one • – Long delay (Satellite) Long delay (Satellite) – – – Low bandwidth (Dial Low bandwidth (Dial- -up modem) up modem)

  22. Reliable Multicast over Reliable Multicast over Unidirectional Satellite Unidirectional Satellite Link (UDL) Link (UDL) Wacharapol P., P., Wacharapol Patcharee Basu Patcharee Basu & & Kanchana Kanchanasut Kanchana Kanchanasut

  23. Unidirectional satellite link Unidirectional satellite link Unidirectional Satellite Link Feed router Receiving routers UDL Receiving networks UDL feeding networks

  24. Bulk Data Transfer over Bulk Data Transfer over Satellite Link Satellite Link • One-to-many IP-based content delivery protocol • Provide reliability without relying on acknowledgement • Support reliable bulk transfer for any media to co-exist with streaming applications • Unique satellite characteristics are taken into design consideration • Scalable to accommodate large number of receivers • Implemented and tested on real satellite link. • Windows and Unix version

  25. Broadcast Disk Broadcast Disk

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