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20-751 ECOMMERCE TECHNOLOGY FALL 2003 COPYRIGHT © 2003 MICHAEL I. SHAMOS Wireless Technologies 20-751 ECOMMERCE TECHNOLOGY FALL 2003 COPYRIGHT © 2003 MICHAEL I. SHAMOS Outline • Wireless technology overview • Cellular communications • Satellite systems • Wireless LAN – 802.11, Bluetooth, UWB • Mobility support – WAP • Wireless applications 20-751 ECOMMERCE TECHNOLOGY FALL 2003 COPYRIGHT © 2003 MICHAEL I. SHAMOS Why Wireless? • Human freedom – Portability v. Mobility • Objective: “anything, anytime, anywhere” • Mobility – Size, weight, power – Functionality – Content • Infrastructure required • Cost – Capital, operational 20-751 ECOMMERCE TECHNOLOGY FALL 2003 COPYRIGHT © 2003 MICHAEL I. SHAMOS Worldwide Mobile Subscribers SOURCE: CTIA, iGillottResearch, 2001 20-751 ECOMMERCE TECHNOLOGY FALL 2003 COPYRIGHT © 2003 MICHAEL I. SHAMOS Electromagnetic Spectrum SOURCE: JSC.MIL SOUND LIGHT RADIO HARMFUL RADIATION VHF = VERY HIGH FREQUENCY UHF = ULTRA HIGH FREQUENCY SHF = SUPER HIGH FREQUENCY EHF = EXTRA HIGH FREQUENCY 4G CELLULAR 56-100 GHz 3G CELLULAR 1.5-5.2 GHz 1G, 2G CELLULAR 0.4-1.5GHz UWB 3.1-10.6 GHz 20-751 ECOMMERCE TECHNOLOGY FALL 2003 COPYRIGHT © 2003 MICHAEL I. SHAMOS MOBILE FIXED MARITIME MOBILE BROADCAST AERO RADIOLOCATION 20-751 ECOMMERCE TECHNOLOGY FALL 2003 COPYRIGHT © 2003 MICHAEL I. SHAMOS Wireless Telephony SOURCE: IEC.ORG AIR LINK PUBLIC SWITCHED TELEPHONE NETWORK WIRED 20-751 ECOMMERCE TECHNOLOGY FALL 2003 COPYRIGHT © 2003 MICHAEL I. SHAMOS Cell Clusters SOURCE: IEC.ORG ACTUAL COVERAGE AREA OF CELL 1 ACTUAL COVERAGE AREA OF CELL 3 CELL 1 OVERLAPS 6 OTHERS DIFFERENT FREQUENCIES MUST BE USED IN ADJACENT CELLS SEVEN DIFFERENT SETS OF FREQUENCIES REQUIRED 20-751 ECOMMERCE TECHNOLOGY FALL 2003 COPYRIGHT © 2003 MICHAEL I. SHAMOS Space Division Multiple Access (SDMA) PATTERN CAN BE REPLICATED OVER THE ENTIRE EARTH 200 FREQUENCIES IN ONE CELL TOTAL NUM BER OF FREQUENCIES = 1400 WORLDWIDE MANY CELLS CAN SHARE SAME FREQUENCIES IF SEPARATED IN SPACE 20-751 ECOMMERCE TECHNOLOGY FALL 2003 COPYRIGHT © 2003 MICHAEL I. SHAMOS Cell Handover SOURCE: R. C. LEVINE, SMU AS PHONE MOVES FROM CELL “A” TO CELL “B”: • CELL “A” MUST HAND THE CALL OVER TO “B” • PHONE MUST CHANGE FREQUENCIES • CELL “A” MUST STOP TRANSMITTING Minimum performance contour Handover threshold contour A Bx y z ANIMATION