dec 2003 electrical and computer engineering jeff frolik, assistant professor
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TRANSCRIPT
DEC 2003
Outline
• Where are electrical devices used?
• Fields within Electrical Engineering
• Exciting future for Electrical Engineers
• Wireless Communications (in your lifetime)
DEC 2003
Where are Electrical Devices Used?
• Home
• Office
• Medical
• Military
• Manufacturing
• Power
DEC 2003
Home
• Television
• VCR
• Remote Control
• Antenna
• Clock Radio
• Audio Compact Disk
• Home Computer
• Electric Stove
• MP3 Player
• Electric Water Heater
• Microwave Oven
• Video Games
DEC 2003
Work Place
• Desktop PC
• Laptop PC
• Copy/Fax Machine
• Computer Network
• Video Conferencing
• Cellular Telephone
• Supercomputers
DEC 2003
Military
• Radar
• Guided Missile
• Smart Bomb
• Aerospace Electronics
• Autopilot/UAV
• Infrared Imaging
• Digital Image Processing
• Satellite
• Global Positioning System
DEC 2003
Manufacturing
• Robotics
• Inventory Control
• Visual Inspection System
• Electronic Instrumentation
• Computer-controlled Processes
• Semiconductors
• Electric Welding
• Laser Cutting
• Computer Integrated Manufacturing
http://www.extremepumpkins.com/detsciencen.html
DEC 2003
Power Systems
• Power Generator
• Motor
• Transformer
• Transmission Line
• Distribution System
• Alternative Energy Sources
DEC 2003
Fields within Electrical Engineering
• Aerospace Electronics
• Antennas
• Broadcast Technology
• Circuits and Systems
• Communications
• Computers
• Consumer Electronics
• Control Systems
• Education
• Electromagnetics
• Industrial Electronics
• Instrumentation
DEC 2003
More Fields within Electrical Engineering
• Lasers
• Magnetics
• Microwave
• Plasma Science
• Power Electronics
• Reliability
• Robotics
• Semiconductors
• Signal Processing
• Ultrasonics
• Vehicular Technology
DEC 2003
Exciting Future for Electrical and Computer Engineers
• High Definition TV
• Superconductors
• Smart Weapons
• Supercomputers
• Electric Cars
• Micromotors
• Sensing Computers
• Virtual Reality
• Microelectromechanical Systems (MEMS)
• Video Phones
• Lasers
• Clean Power Sources
• Smart Cars
• Smart Robots
• Computer Vision
DEC 2003
Wireless Communication Systems: WHY?
Camel’s Hump School survey:
1. Better what?
2. Better what?
3. Better what?
DEC 2003
Wireless Communication Systems: WHY?
Wired transmission media - wire/fiber
Wireless transmission media - air
• Quick installation of infrastructure • e.g., straight to mobile in developing countries
• User mobility • Shared access of channel (airwaves)
DEC 2003
Frequency Spectrum
How is the “air” shared?
Different applications use different frequency bands:
• AM radio: 530-1600 kHz• FM radio: 88-108 MHz• TV: CH 2-13: 54-88 & 178-216 MHz
CH 14-83: 470-890 MHz• Cellular: 824-894 MHz• Cellular PCS: 1.8-2.0 GHz• Wi-Fi: 2.45-2.50 GHz, 5.725-5.875 GHz• DBS Satellite: 12.2-12.7 GHz
Note: the higher you go in frequency, the more “room” you have
Spectrum Analyzer
DEC 2003
Mobile Communications
Two-way Radio
1. Pro
2. Pro
3. Con
4. Con
Cell Phone
1. Pro
2. Pro
3. Con
4. Con
DEC 2003
1G Cellular Systems (1983)
“Advanced” Mobile Phone System (AMPS)
• Limited coverage: few cell towers
• Channelized analog system
What was wrong with it?
DEC 2003
1G Cellular Systems (1983)
“Advanced” Mobile Phone System (AMPS)
• Limited coverage: few cell towers
• Channelized analog system
What was wrong with it?
Hint: What is the biggest component in your cell phone?
DEC 2003
1G Cellular Systems (1983)
“Advanced” Mobile Phone System (AMPS)
• Limited coverage: few cell towers
• Channelized analog system
Question what was wrong with it?
Battery Killer
• Few sites – further distance to transmit
• Analog system – always sending a signal during call
DEC 2003
The Fix
Demand for service
• Increased coverage area
• Increase cell density
Advances in digital technology
• 2G systems (1993)
• Digital systems compress and send “data” as available
Result: more efficient use of batteries
• Less distance to send
• Less time sending
DEC 2003
What’s next?
3G systems
• Voice
• Internet
• Music
• Video
• Games
Images courtesy: Motorola
DEC 2003
What’s next?
3G systems
• Voice
• Internet
• Music
• Video
• Games
Images courtesy: Motorola
Problem?
DEC 2003
What’s next?
3G systems
• Voice
• Internet
• Music
• Video
• Games
Images courtesy: Motorola
Problem: more time on per hour results in shorter battery life
DEC 2003
Television Broadcasting
• Terrestrial Broadcast TV
• An analog system of limited range
• Each channel occupies 6 MHz
• Regular Cable: same technology, just over wire
• Need for an alternative?
• Cable not available everywhere
• Cable had a “monopoly”
• Analog system had a limited number of channel (82)
DEC 2003
Direct to Home Satellite TV (1986)
C-band (4 GHz)
• 6 foot dishes
Analog system
• 6 MHz channels
• Few channels per satellite
Image: Dave’s Web Shop
DEC 2003
Direct to Home Satellite TV (1986)
C-band (4 GHz)
• 6 foot dishes
Analog system
• 6 MHz channels
• Few channels per satellite
Image: Dave’s Web Shop
Problems?
DEC 2003
Direct to Home Satellite TV (1986)
C-band (4 GHz)
• 6 foot dishes
Analog system
• 6 MHz channels
• Few channels per satellite
Image: Dave’s Web Shop
Problems:• cumbersome/expensive equipment• expensive hardware• limited channel selection
DEC 2003
DBS Receiver Technology
• Ku-band (higher frequency) enables small receiving dish
• Digital signal provides
• CD quality sound
• “Better” picture
• Additional services
• More channels: “500!”
DEC 2003
DBS Summary
• Promise of high-quality, nation-wide service obtained• DirecTV and Echo Star
• Advantages• Easy to add new customers (database change)
• Disadvantages• Large customer and venture investment up-front• No standard among providers• Compression can break down• Cable has caught up• Limited bandwidth, HDTV? • Rainfade (FL - high gain slope and rain rates)
DEC 2003
Satellite Radio (2002)
• Two competing and incompatible systems: XM and Sirius
• Like Direct Broadcast Television in idea
• Smaller antenna
• No need to point
• Coming next, Digital Radio in the AM and FM bands.
• Static free
• Additional features (e.g., play list)
Image: Sony
DEC 2003
Iridium (1998)
• Cell coverage around the world through a 66 satellite network• Low earth orbit: 485 miles
• First phones were brick size/weight• Pricing is way too high (dollars/minute) for
general consumer• Land based systems in other countries built
out faster than expected• $4 B and company filed for bankruptcy• Niche market for private planes, boats, artic
explorers and military
• Lesson learned (probably not): Just because you can do something, doesn’t mean you should
Source: Iridium
DEC 2003
Wireless Networks (2000)
Laptop Laptop
Laptop
Network
W-LAN
802.11 b (WI-FI)
Slave-PDA
Slave-Cell
Slave-Laptop
Master-Car
W-PAN
Bluetooth
DEC 2003
Coverage Area in Wireless
Source: University of Kansas' Information & Telecommunications Technology Center and Kansas Applied Remote Sensing Program
Not uniform in practice
DEC 2003
So what is happening now!
TODAY: 10 million users in the US check mail or surf the web wirelessly via mobile phones or handheld computers
• WLAN• 802.11b (11 Mbps) and Bluetooth (720 kbps)
• Satellite based systems• XM and Sirius digital radio• OnStar telematics
• In building wireless• Your mobile phone becomes part of the company exchange inbuilding• Maintains regular mobile functions off-campus
• THE FIELD IS MARKET DRIVEN!
DEC 2003
What is Next? Wireless Sensor Networks
Very sophisticated, low-cost and ubiquitous sensing networks using many, broadly distributed sensors
NETWORK
3G, WLAN
DEC 2003
Very sophisticated, low-cost and ubiquitous sensing networks using many, broadly distributed sensors
The system is sophisticated but the individual components can be “dumb”
Wireless Sensor Networks
DEC 2003
Why is this an important area?
Industry~90% of instrumentation costs deal with installation
(e.g., mounting and routing of cabling)
MilitaryCan sensor systems replace human sentinels and save lives?
EnvironmentalIn situ sensing is more accurate than remote sensing
DEC 2003
Sample Wireless Sensor Application:Smart Bobbers
• Ubiquitous sensing of watershed
processes (e.g., chemicals,
hydrology and nutrients)
• Fully integrated floating sensing,
processing and communicating
device
• Information enables dynamic
modeling and adaptive
management of resources
Data Reception & Sensor Fusion
DynamicModeling
Adaptive Management
Watershed
CN
HH
HN
N CC
DEC 2003
End Result:Remote
Monitoring of Spatial-
Temporal Data
http://quake.wr.usgs.gov/recenteqs/latest.htm
DEC 2003
Math is Important!
• FM modulation
)sin()(!3
1)cos()(
!2
1)sin()(cos
))(cos())(cos()(
2222 ttakttakttaktA
taktAdmktAt
cfcfcfc
fc
t
fcFM
CALCULUS – Power Series Expansion
DEC 2003
Communications is Important!
• Engineers must be able to communicate their ideas
• To their colleagues/clients
• In written reports
• In oral presentations
DEC 2003
Key Points
• Electrical Engineers work in all aspects of society
• In less than 20 years, wireless communications has become nearly ubiquitous
• Technology without a market is doomed to fail
• Your math courses and communication skills form a key foundation for electrical engineering
• The future is up to you!