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Wireless Technologies. SOFYAN BASUKI Sofmae4@gmail.com 085724677888 085320900567. Wireless technology overview Cellular communications Satellite systems Wireless LAN 802.11, Bluetooth, UWB Mobility support WAP Wireless applications. Outline. Human freedom Portability v. Mobility
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Wireless Technologies SOFYAN BASUKI Sofmae4@gmail.com 085724677888 085320900567
Wireless technology overview • Cellular communications • Satellite systems • Wireless LAN • 802.11, Bluetooth, UWB • Mobility support • WAP • Wireless applications Outline
Human freedom • Portability v. Mobility • Objective: “anything, anytime, anywhere” • Mobility • Size, weight, power • Functionality • Content • Infrastructure required • Cost • Capital, operational Why Wireless?
Worldwide Mobile Subscribers SOURCE: CTIA, iGillottResearch, 2001
4G CELLULAR 56-100 GHz 3G CELLULAR 1.5-5.2 GHz 1G, 2G CELLULAR 0.4-1.5GHz HARMFUL RADIATION LIGHT RADIO SOUND VHF = VERY HIGH FREQUENCY UHF = ULTRA HIGH FREQUENCY SHF = SUPER HIGH FREQUENCY EHF = EXTRA HIGH FREQUENCY UWB 3.1-10.6 GHz Electromagnetic Spectrum SOURCE: JSC.MIL
MARITIME MOBILE FIXED BROADCAST MOBILE AERO RADIOLOCATION
WIRELESS AIR LINK WIRED PUBLIC SWITCHED TELEPHONE NETWORK Wireless Telephony SOURCE: IEC.ORG
ACTUAL COVERAGE AREA OF CELL 3 ACTUAL COVERAGE AREA OF CELL 1 CELL 1 OVERLAPS 6 OTHERS DIFFERENT FREQUENCIES MUST BE USED IN ADJACENT CELLS SEVEN DIFFERENT SETS OF FREQUENCIES REQUIRED Cell Clusters SOURCE: IEC.ORG
MANY CELLS CAN SHARE SAME FREQUENCIES IF SEPARATED IN SPACE PATTERN CAN BE REPLICATED OVER THE ENTIRE EARTH 200 FREQUENCIES IN ONE CELL TOTAL NUMBER OFFREQUENCIES = 1400 WORLDWIDE Space Division Multiple Access (SDMA)
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 A x y B z Cell Handover Handover threshold contour ANIMATION SOURCE: R. C. LEVINE, SMU
MACROCELL: $1M FAST-MOVINGSUBSCRIBERS PICOCELLS MICROCELL: $250K SLOW-MOVINGSUBSCRIBERS GSM: 100m - 50 km 250 km/hr Cell Sizes
Many users sharing a resource at the “same time” • Needed because user must share cells • FDMA (frequency division) • Use different frequencies • TDMA (time division) • Use same frequency, different times • CDMA (code division) • Use same frequency, same time, different “codes” Multiple Access
Advantages: • No dynamic coordination Disadvantages: • Inflexible & inefficient if channel load is dynamic and uneven Each channel gets a band (range) of frequencies Used in traditional radio, TV, 1G cellular k1 k2 k3 k4 k5 k6 c f Frequency Division Multiplexing (FDMA) t SOURCE: NORMAN SADEH
k1 k2 k3 k4 k5 k6 c FREQUENCY BAND f t Each channel gets entire spectrum for a certain (rotating) time period EACH CHANNEL OCCUPIES SAME FREQUENCY Advantage: Can assign more time to senders with heavier loads 3X capacity of FDMA, 1/3 of power consumption Disadvantage: Requires precise synchronization Time Division Multiplexing (TDMA) SOURCE: NORMAN SADEH
k1 k2 k3 k4 k5 k6 c f t Each channel gets a certain frequency band for a certain amount of time. Example: GSM • Advantages: • More robust against frequency- selective interference • Much greater capacity with time compression • Inherent tapping protection • Disadvantages • Frequency changes must be coordinated Combining TDMA and FDMA SOURCE: NORMAN SADEH
Time-Division Multiple Access SOURCE: QUALCOMM
k1 k2 k3 k4 k5 k6 c f t • Each channel has unique“code” • All channels use same spectrumat same time but orthogonal codes • Advantages: • bandwidth efficient – code space is huge • no coordination or synchronizationbetween different channels • resists interference and tapping • 3X capacity of TDMA, 1/25 power consumption • Disadvantages: • more complex signal regeneration • Implemented using spread spectrum Code Division Multiplexing (CDMA)
First • Analog, circuit-switched (AMPS) • Second • Digital, circuit-switched (GSM, Palm) 10 Kbps • Advanced second • Digital, circuit switched, Internet-enabled (WAP) 10 Kbps • 2.5 • Digital, packet-switched, TDMA (GPRS, EDGE)40-400 Kbps • Third • Digital, packet-switched, wideband CDMA (UMTS)0.4 – 2 Mbps • Fourth • Data rate 100 Mbps; achieves “telepresence” Cellular Generations
CELL TRANSMITTER & RECEIVER INTERFACE TO LANDTELEPHONE NETWORKS HIERARCHY OF CELLS STOLEN, BROKEN CELLPHONE LIST LIST OF ROAMINGVISITORS PHONE ENCRYPTION, AUTHENTICATION LIST OF SUBSCRIBERS IN THIS AREA SIM: IDENTIFIES A SUBSCRIBER DATA RATE: 9.6 Kbps GSM Architecture SOURCE: UWC
Integral part of GSM standard • Added to other standards as well • Uses control channel of phone • Send/Receive short text messages • Sender pays (if from mobile phone) • Phone has "email" address • SMTP Interface • Only in the US, not the rest of the world • Allows messages to be sent for free! • 3125551234@wireless.att.net • 1 BILLION SMS/day worldwide SMS – Short Message Service SOURCE: GEMBROOK SYSTEMS
Bank Web Site Customer Internet Alert me to all credit card transactions greater than $100. Message from YourBank: Credit card purchase of $1245 at Joe’s HiFi. Bank Back-end Systems SMS Monitoring Application Air Credit card used Joe’s HiFi $1245 Message appears within seconds on the customer’s phone Wireless Carrier SMS Carrier Cell Tower SMS in Banking SOURCE: GEMBROOK SYSTEMS
GEO MEO LEO GEO (22,300 mi., equatorial) high bandwidth, power, latency MEO high bandwidth, power, latency LEO (400 mi.) low power, latency more satellites small footprint V-SAT (Very Small Aperture) private WAN SATELLITE MAP Satellite Systems SOURCE: WASHINGTON UNIV.
Geostationary Orbit SOURCE: BILL LUTHER, FCC
Global Positioning System • Operated by USAF • 28 satellites • 6 orbital planes at a height of 20,200 km • Positioned so a minimum of 5 satellites are visible at all times • Receiver measures distance to satellite GPS Satellite Constellation SOURCE: NAVSTAR
DISTANCE MEASUREMENTS MUST BE VERY PRECISE LIGHT TRAVELS 1018 FEET EACH MICROSECOND GPS Trilateration SOURCE: PETER DANA
Benefits of AVL • Fast dispatch • Customer service • Safety, security • Digital messaging • Dynamic route optimization • Driver compliance • Sample AVL Users • Chicago 911 • Inkombank, Moscow • Taxi companies Automatic Vehicle Location (AVL) Intelligent Highway demo CA SOURCE: TRIMBLE NAVIGATION
Vehicle tracking • Firemen in buildings, vital signs, oxygen remaining • Asset tracking • Baggage • Shoppers assistance • Robots • Corporate visitors • Insurance • Barges Location-Aware Applications
Idea: just a LAN, but without wires • Not as easy since signals are of limited range • Unlike wired LAN, if A can hear B and B can hear C, not necessarily true that A can hear C • Uses unlicensed frequencies, low power • 802.11 from 2 Mb to 54 Mb • Bluetooth • UWB Wireless LAN
Extended Range Antenna WaveLAN ISA (Industry Standard Architecture) Card WavePOINT II Transmitter Ethernet Converter Wireless LAN Components 11 Mbps WaveLAN PCMCIA Card SOURCE: LUCENT
CLIENT AND ACCESS POINT WIRELESS PEER-TO-PEER BRIDGING WITH DIRECTIONAL ANTENNAS Wireless LAN Configurations MULTIPLE ACCESS POINTS + ROAMING UP TO 17 KM ! SOURCE: PROXIM.COM
A standard permitting for wireless connection of: • Personal computers • Printers • Mobile phones • Handsfree headsets • LCD projectors • Modems • Wireless LAN devices • Notebooks • Desktop PCs • PDAs Bluetooth
Operates in the 2.4 GHz Industrial-Scientific-Medical (ISM) (unlicensed)! band. Packet switched. 1 milliwatt (as opposed to 500 mW cellphone. Low cost. • 10m to 100m range • Uses Frequency Hop (FH) spread spectrum, which divides the frequency band into a number of hop channels. During connection, devices hop from one channel to another 1600 times per second • Bandwidth 1-2 megabits/second • Supports up to 8 devices in a piconet (two or more Bluetooth units sharing a channel). • Built-in security. • Non line-of-sight transmission through walls and briefcases. • Easy integration of TCP/IP for networking. Bluetooth Characteristics
ALCATEL One TouchTM 700 GPRS, WAP ERICSSON R520 GSM 900/1800/1900 ERICSSON BLUETOOTH CELLPHONE HEADSET Bluetooth Devices NOKIA 9110 + FUJI DIGITAL CAMERA ERICSSON COMMUNICATOR
Piconet = small area network • “Ad hoc” network: no predefined structure • Based on available nodes and their locations • Formed (and changed) in real time Bluetooth Piconets
Scatternet Piconets Master Master / Slave Slave Piconet ScatterNet Bluetooth Scatternets SOURCE: KRISHNA BHOUTIKA
“0” “1” 500 ps d d Frequency (GHz) Randomized Time Coding d = 125 ps 0 -40 Power Spectral Density (dB) Amplitude Random noise signal Time -80 Frequency (GHz) 1 2 3 4 5 • Not a sinewave, but millions of pulses per second • Time coded to make noise-likesignal • Pulse position modulation Spread Spectrum Time-Modulated Ultra-Wideband (TM-UWB) SOURCE: TIME DOMAIN
PulsON, A Chip Based Solution • VERY low power: 0.01 milliwatt • Bluetooth 1 milliwatt (100 x UWB) • Cellphone 500 milliwatts (50,000 x UWB) • Range: 30 to 300 feet • Very small • Low cost • 100 Mbits/second • Up to 500 Mbps for short distances(USB speed) • No interference • Secure Ultra Wideband Properties
WAP (Wireless Application Protocol) and iMode • High-level protocols that use cellular transport • WAP: • Uses WML (Wireless Markup Language) • Divides content into “cards” equal to one telephone screen • Simplified but incompatible form of HTML • To send to a WAP phone, must broadcast WML content Wireless Application Support
Internet MobileNetwork Web Content Server Non Mobile Internet User WAP Gateway Mobile Terminal iNexware Database Server WAP Applications WAP simulator SOURCE: DANET
Telephone, pager, email, browser, location tracking, banking, airline tickets, entertainment tickets, games • NTT DoCoMo (ドコモ means “anywhere”) • Japan is the wireless Internet leader: iMode iMode FAQ SOURCE: EUROTECHNOLOGY JAPAN K.K.
Sits on top of packet voice/data transport • As of July 31, 2003, > 39 million subscribers • 28,000 new ones per day • 26% of Japan • >3000 “official” sites • >1000 application partners • >40,000 unofficial sites • Fee based on amountof data transmitted iMode SOURCES: XML.COM, EUROTECHNOLOGY.COM
Phonetic text input (better for Japanese) • SLOW: 9.6 Kbps, but 3G will raise to 384 K • Uses cHTML (compact HTML) • same rendering model as HTML (whole page at a time) • low memory footprint (no tables or frames) • Standby time: 400 min., device weight 2.4 oz. (74g) iMode SOURCES: XML.COM, NTT
BILLING DB INTERNET INFO PROVIDER USER DB IP IP DoCoMo Packet Network (PDC-P) iMode Servers HTTP PACKET DATA iMode Operation SOURCE: SAITO & SHIN
Wireless Standards • 802.11b (2.4 GHz 300’ radius 11 Mbps) • 802.11a (5 GHz 54 Mbps incompatible with b) • 802.11g (2.4 GHz 54 Mbps backward compatible with b) • 802.20 (<3.5 GHz >1 Mbps @250 kph) • BlueTooth (2.4 Ghz 30’ radius) • GSM (9.6 Kbps) GPRS (28.8 Kbps up to 60 Kbps ) • 3G (UMTS 1.1 Mbit/s shared typically giving 80 Kbit/s ) • 4G2010? (10 Mbs? ) • UWB potential to deliver 500 Mbps over short distances SOURCE: JOHN DOWNARD
Mobile growing very rapidly • Cell systems need large infrastructure • Wireless LAN does not • Content preparation is a problem • Wireless business models largely unexplored • Bandwidth, bandwidth, bandwidth Key Takeaways
Q A &
DATA 1 0 1 “CODE” 0 1 0 1 0 0 1 0 0 0 1 0 1 1 0 0 1 1 DATA CODE 1 0 1 0 1 1 1 0 0 0 1 0 0 0 1 1 0 0 +1 ACTUAL SIGNAL -1 Code Division SOURCE: JOCHEN SCHILLER
DATA B 1 0 0 “CODE” B 0 0 0 1 1 0 1 0 1 0 0 0 0 1 0 1 1 1 DATA CODE 1 1 1 0 0 1 1 0 1 0 0 0 0 1 0 1 1 1 +1 ACTUAL SIGNAL B -1 Code Division SOURCE: JOCHEN SCHILLER
+1 ACTUAL SIGNAL B -1 +1 ACTUAL SIGNAL A -1 +2 ACTUAL SIGNAL A+B Two CDMA Signals -2 SOURCE: JOCHEN SCHILLER
+2 ACTUAL SIGNAL A+B -2 “CODE” A 0 1 0 1 0 0 1 0 0 0 1 0 1 1 0 0 1 1 +1 -1 +2 -(A+B) * CODE A -2 0 INTEGRAL Recovering Data A From A+B 1 1 SOURCE: JOCHEN SCHILLER