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 ECE 4730: Lecture #1 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 ECE 4730: Lecture #1 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
2005  2.2 Billion!!
2010  4.6 Billion!!
65% of World Population!!
ECE 4730: Lecture #1

5. Frequencies ECE 4730: Lecture #1 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/ (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
AMPS
AMPS
PCS
PCS
Fig
pg. 592
PCS
PCS
Reallocated to PCS
802.11b Wi-Fi
802.11a Wi-Fi
ECE 4730: Lecture #1

10. U.S. Mobile Radio Spectrum
SMR Bands  Specialized Mobile Radio
Three 20 MHz bands from 800900 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
902928 MHz and 24002484 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 2.4 GHz
ECE 4730: Lecture #1

12. U.S. Mobile Radio Spectrum
1st Generation (1G) Cellular Telephone
AMPS: Advanced Mobile Phone System
824849 MHz
Reverse Channel: Xmit from mobile to base station (fixed)
869894 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
1.851.99 GHz
FCC Spectrum Auctions 1998 &  $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, , 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 = GHz (reallocated from MMDS)
ECE 4730: Lecture #1

15. U.S. Mobile Radio Spectrum
Analog Broadcast TV Frequencies  recent reallocation
Broadcast TV channels 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
5.155.35 GHz & 5.7255.825 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
ECE 4730: Lecture #1