ece 4730: lecture #1 1 wireless communications “it is dangerous to put limits on wireless.”...

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ECE 4730: Lecture #1 1 Wireless Communications “It is dangerous to put limits on wireless.” Guglielmo Marconi, 1932 Nobel Prize Winner Inventor of Radio

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ECE 4730: Lecture #1 1

Wireless Communications

“It is dangerous to put limits on wireless.”

Guglielmo Marconi, 1932

Nobel Prize Winner

Inventor of Radio

ECE 4730: Lecture #1 2

History Wired Communications

1834 Gauss and Weber build telegraph system in Germany 1844 Morse connects Baltimore and Washington by telegraph 1858 First transatlantic telegraph cable laid 1876 Alexander Bell demonstrates telephone 1911 New York can telephone Denver 1918 First telephone carrier system with multi-plexing 1945 First digital computer (ENIAC) 1956 First transatlantic telephone cable 1965 First packet switched computer network (ARPANET) 1981 IBM personal computer 1995 World Wide Web 1998 Internet usage expands exponentially

ECE 4730: Lecture #1 3

History Wireless Communications Not so “new”

1899 Marconi sends first radio message across Atlantic 1905 Hulsmeyer detects ships with radar 1927 US & Europe telephones linked by HF radio 1934 AM mobile police radios for public safety widely used 1935 Armstrong demonstrates FM radio system 1940 First microwave radar 1965 First commercial communication satellite 1968 AT&T proposes cellular phone system to FCC 1983 FCC allocates spectrum for analog cellular service (AMPS) 1990 GSM digital cellular service introduced in Europe 1995 FCC auctions new PCS licenses in U.S. for digital services 1998 40 million cellular phone users in U.S. (20% of adults) 2002 62% of U.S. adults own a cell phone

ECE 4730: Lecture #1 4

Cell Phone Useage

1990 8 million worldwide users

2002 700 million worldwide users

2005 2.2 Billion!!

2010 4.6 Billion!!

65% of World Population!!

ECE 4730: Lecture #1 5

Frequencies RF = Radio Frequencies

1 MHz to 1 GHz» general classification, not absolute

50 MHz to 1 GHz» more widely used definition

Microwave Frequencies 1 GHz to 300 GHz general 1 GHz to 100 GHz more widely used

Trend towards use of higher frequencies Greater signal bandwidth (BW) Max. BW 10% of fc More users and/or higher data rates More difficult to design !! more $$ Propagation distance as frequency

ECE 4730: Lecture #1 6

Wireless Applications Mature

Appliances» Garage door opener» Car alarms» TV/VCR remote» Cordless phones

Communications» Fixed microwave (point-to-point or LOS) nearly 20,000 in U.S.!» Satellite to fixed ground stations (TV, phone, defense, etc.)» Paging » 1st generation (1G) analog cellular AMPS (FM)» 2nd generation (2G) digital cellular IS-95, IS-136, GSM» 3rd generation (3G) digital cellular UMTS, CDMA2000» WLAN: Wireless Local Area Networks (WiFi)

ECE 4730: Lecture #1 7

Wireless Applications Becoming Mature

Mobile computers/email (3G/4G) Wireless Local Loop (WLL)

» Local phone service via wireless connection» Very prominent in non-industrialized nations» Cheaper to install than wired lines» Local competition from long-distance carriers in U.S.!

Satellite to mobile ground units Land Mobile Satellite (LMS)» Constellation of 66 satellites in orbit (plus spares)» Motorola/Iridium Bankrupt in 2001! (now Iridium Communications)

4G Digital Cellular/PCS LTE PCS = Personal Communication Services

ECE 4730: Lecture #1 8

Wireless Applications

Long-term trends in mobile communications driven by: 1) Technology

» Integrated Circuits (ICs) cheaper, smaller, faster, etc.

» RF/microwave circuit fabrication higher frequencies (MMICs)

» Digital Signal Processing (DSP) chips

» Customized for specific applications (e.g. ASICs)

» Baseband signal processing

» Coding, modulation, encryption, equalization, etc.

2) Governments (e.g. FCC)» Spectrum allocation

» Public use vs. $$ from auctions

» Regulations

» International standards

ECE 4730: Lecture #1 9

U.S. Mobile Radio Spectrum

Fig. 11.23pg. 592

AMPS AMPS PCS PCS

PCSPCS Reallocated to PCS

802.11a Wi-Fi

802.11b Wi-Fi

ECE 4730: Lecture #1 10

U.S. Mobile Radio Spectrum

SMR Bands Specialized Mobile Radio Three 20 MHz bands from 800900 MHz Large number of private licenses nationwide Paging/messaging Voice dispatch taxi, P/F/A Data (UPS/Fedex) Extended SMR

» Nextel/Motorola partnership bought by Sprint» Purchased SMR licenses all over the country» Nationwide coverage providing digital cellular/data service

ECE 4730: Lecture #1 11

U.S. Mobile Radio Spectrum

ISM Bands Industrial/Scientific/Medical 902928 MHz and 24002484 MHz

» Unlicensed “garbage” bands

Anyone can develop application as long as FCC guidelines are met» Spread spectrum modulation must be used» Tx power level < 1 W

Remote meter reading Wireless medical monitors Digital cordless telephones 802.11b IEEE WLAN standard @ 2.4 GHz

ECE 4730: Lecture #1 12

U.S. Mobile Radio Spectrum

1st Generation (1G) Cellular Telephone AMPS: Advanced Mobile Phone System 824849 MHz

» Reverse Channel: Xmit from mobile to base station (fixed)

869894 MHz» Forward Channel: Xmit from base station to mobile

FCC mandated duopoly in Major Trading Areas (MTAs) MTA = 51 largest U.S. cities Two providers/MTA

» e.g. Cellular One + Southwestern Bell Mobile in K.C.

All MTA providers have upgraded to 2G/3G systems 1G AMPS still used only sparsely in rural areas

ECE 4730: Lecture #1 13

U.S. Mobile Radio Spectrum

Digital PCS Band 1.851.99 GHz FCC Spectrum Auctions 1998 & 2000 $10 Billion!!

» 1st time spectrum sold for $$ in U.S.

A & B blocks for MTAs» Duopoly like AMPS

C, D, E, & F blocks Basic Trading Areas (BTAs)» BTA = 492 large rural areas (includes MTAs!)

2nd Generation (2G) digital cellular phone service + PCS PCS = messaging, caller ID, voice mail, email, data, etc. Compete with analog cellular and SMR services combined

ECE 4730: Lecture #1 14

U.S. Mobile Radio Spectrum

3rd Generation (3G) Cellular Telephone AT&T (HSPA)

» 850 & 1900 MHz (AMPS + PCS)

Verizon (CDMA)» 800 & 1900 MHz (AMPS + PCS)

T-Mobile (HSPA)» 1700 MHz (forward link) & 2100 MHz (reverse link)

Sprint (CDMA)» 850 MHz & 1800 MHz (AMPS + PCS)» New 4G network = 2.5 - 2.7 GHz (reallocated from MMDS)

ECE 4730: Lecture #1 15

U.S. Mobile Radio Spectrum

Analog Broadcast TV Frequencies recent reallocation Broadcast TV channels 52-69 relinquished in the switchover to digital 700 – 800 MHz Split into 5 blocks (A-E) by FCC for 3G/4G use Auctioned by FCC for $19.6 billion Block A (12 MHz)

» 698 – 704 & 728 – 734 MHz Block B (12 MHz)

» 704 – 710 & 734 – 740 MHz Block C (22 MHz)

» 746 – 757 & 776 – 787 MHz Block D (6 MHz)

» 758 – 763 & 788 – 793 MHz Block E (10 MHz)

» 722 – 728 MHz

ECE 4730: Lecture #1 16

U.S. Mobile Radio Spectrum

UNII Unlicensed National Information Infrastructure Allocated in 1997 for “public use” applications 5.155.35 GHz & 5.7255.825 GHz

» 300 MHZ of available spectrum

WLL, wireless internet access, and WLAN applications 802.11a IEEE WLAN standard Only spectrum in U.S. with enough BW to support very high data rate

services (> 20 Mbps)» High speed WLAN

» Wireless ATM

Campus or building applications» High frequency poor signal propagation & geographic coverage

» Will NOT support cellular phone applications