Transcript Slide 1
School on Radio Use for Information and Communication Technology The Abdus Salam International Centre for Theoretical Physics ICTP Trieste (Italy) 3 - 21 February 2003 Alternative Internet Access Technologies Prof. R. Struzak [email protected] These are preliminary notes, intended only for distribution to participants Topics for discussion Current research activities in various countries aimed at making internet access less expensive and/or more practical: – PLT – HAP – Beware of misprints!!! Existing Technologies Strengths Weaknesses Fiber Large bandwidth Capital/ Labor intensive Cable Popular in many rich countries Capital/ Labor intensive xDSL Popular in cities/ rich countries Distance limits availability Radio Rapid deployment Coverage problems Satellite Ubiquitous coverage Capital intensive Most have lengthy/ costly deployment process, especially new installations Power Line Telecommunication • Electric power transmission network much more developed than telecommunication network • New high-power, high-voltage power lines integrated with fiber optic cable • Low-power line exist in most houses PLC References • Bartak GF, Powerline Communication Systems…,IEEE Internat. EMC 2003 Sympos., Istanbul • Olsen RG, Technical Considerations for Wideband Powerline Communication, IEEE Internat. EMC 2003 Sympos., Istanbul • Vick D, PLC Workshop, Internat. Wroclaw EMC 2000 Sympos. (first findings & simulations) • Hansen D, Update on Power Line Telecommunication Activities in Europe, IEEE Internat. EMC 2003 Sympos., Istanbul • www.PLCforum.com • www.plca.net • www.ipcf.org • www.ascom.ch • www.broadband.ch PLC Forum Presentation Bucharest 2002 HAP HAP – High Altitude Platforms • High Altitude Platform Stations technology is a way to keep antenna at high altitude (stratospheric heights of ~20 km) at low cost • It has a potential of high capacity & coverage: a single platform has >1000 X capacity of satellite (in bps/km2) • The stations are rapidly deployable (system set up in days, providing instant market coverage) • Relatively inexpensive: the cost of the complete system is expected to be a fraction of the cost of satellites & terrestrial systems such as cable, DSL, or fiber to deploy ($/subscriber) • Easy maintenance: Platforms brought down at will for maintenance/ upgrade • Easily re-locatable • Complement to terrestrial & satellite systems • Low power (~1W –compare with 10kW for typical terrestrial broadcast) • Multiple applications – – – – Fixed/mobile broadband Fixed/mobile voice Direct broadcating video/audio Non-telecom applications • (e.g. environmental observations) HAPS’ Footprint • For a given altitude, the diameter of HAPS’ footprint is R d 2 R arccos cos R_h R Earth radius (6'378 km) the minimum elevation angle h altitude • For elevation of 150, the footprint is of ~150 km diameter, for 00 - ~1000 km diameter. HELIOS Flying HAP References • Many publications & ITU documents • HAPS-High Altitude Platform Stations, Federal Office of Communications, Switzerland • http://skystation.com (presentation) • www.angelhalo.com • www.airship.com • www.plfm.net • www.ga.com/avcs/index.html • http:/www1.tlc.polito.it/heliplat • www2.crl.go.jp/team2/ • www2.crl.go.jp/mt/b181/research/spf/index-e.html (presentation) • http://skytowerglobal.com • • www.bacom.ch/imperia/md/content/english/funk/forshungundentwicklung/studien/HA PS.pdf Japanese Presentation Thank you for your attention