Wireless Communication Engineering Fall 2004

1
Wireless Communication Engineering(Fall 2004)

• Lecture 1
• Professor Mingbo Xiao
• Sept. 23, 2004

2
Lets Know Each Other

• My Self-Introduction
• Course Objectives and My Wishes
• Your Self-Introduction (Name, Major, Reasons for
  taking this course, etc.)
• Suggestions are always welcome and sometimes
  required ?

3
Recommended Background

• Digital Communications
• Computer Networks
• Probability and Stochastic Processes

4
Grading

• Final (Exam/Project/Paper) 34
• Midterm 33
• Homework Quiz 33
• NO late submission or
• any type of cheating
• is allowed in this class.
• Homework is due before the next lecture starts.

5
Whats QUIZ?

• QUIZ is also known as POP QUIZ.
• Its a very nice way for the teacher to find out
  who is absent. ?
• It is usually unannounced -B.
• When you find out its real meaning, you may want
  to say it like QUIZzzzzzzzzzz
• Still unclear?

6
QUIZ 1

• Given two boxes of GO chesses. Put a handful of
  the black chesses into the white box, mix them,
  and then take a handful of the mixed chesses back
  to the first box.
• Question Which one is larger, the number of
  black chesses in the white box or the number of
  white chesses in the black box?

7
How about Homework?

• Homework is different from quiz in that you can
  answer it off the class.
• HW1 Answer the following questions in no less
  than 500 English words
• What do you expect to learn from this course? Any
  plan on how to achieve it?
• What are your opinions on the bilingual teaching
  for a major course like this one?

8
Textbook and References

• Wireless Communication and Networks (by William
  Stallings ISBN 0-13-040864-6 Publisher
  Prentice Hall, 2002)
• Wireless Communication and Networks (by Weihua
  Zhuang etc., Chinese edition)
• Principles of Wireless Networks A Unified
  Approach (by Kaveh Pahlavan etc., Publisher
  Science Press, 2003)
• Notes and Handouts

9
Internet and Web Resources

• Web page for the textbook
• WilliamStallings.com/Wireless1e.html
• Useful web sites, errata sheet, figures, tables,
  slides, internet mailing list, etc.
• Student Support Site
• WilliamStallings.com/StudentSupport.html
• Newsgroups
• comp.std.wireless
• comp.dcom.

10
Tentative Course Outline

• Week 1 Introduction of Wireless Networks
  (Evolution, Promises, and Challenges)
• Week 2 Wireless Communication Principles
• Week 3 Computer Networking Basics
• Week 4-5 Wireless Channels and Antenna
• Week 6 Multiple Access Techniques
• Week 7 Concepts of Cellular and 1G Systems
• Week 8-10 2G Cellular Systems

11
Tentative Course Outline (Contd)

• Week 11-12 3G and Beyond Systems
• Week 13 Wireless LANs
• Week 14 Ad Hoc Networks
• Week 15 Mobile IP
• Week 16-17 Exams and Presentations

12
Wireless Is Hot

• Billions of wireless devices are in use
• 4 wireless technologies in 10 communication
  technologies with most market potential
• Wi-Fi
• UWB
• Software Radio
• Wireless Mesh
• Other six are Nanotech, PON, Soft Switching,
  MPLS, FSO, Optical Switching

13
Introductions to Wireless Communications

• Communication is an essential need of human
  being, e.g., conversation, letter
• Wireless used to be the only (limited and
  unreliable) way to communicate in ancient times
  ???????????????????
• Modern wireless communications are based on the
  electromagnetic field theory (Maxwells
  equations, Marconis invention)

14
Introductions to Wireless Communications (Contd)

• Wireless is often prior to its wired counterpart
  and has become an important supplement
• Marconis Wireless Telegraph ? Wired Telegraph
  Telephone ? Cordless, Cellular Telephone, and
  Wireless Local Loop
• Broadcast TV ? Cable TV ? Satellite TV
• Aloha Network ? Ethernet ? Wireless LAN

15
Characteristics of Wireless Comm.

• Convenience and reduced cost
• Service can be deployed faster than fixed service
• No cost of cable plant
• Service is mobile, deployed almost anywhere
• Unreliable channel (attenuation, fading,
  shadowing, interference)
• Complicated design and management
• Device limitations (power supply, LCD)
• Limited bandwidth and expensive service

16
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17
EM Spectrum for Telecom

• Most spectra licensed 3G license is very
  expensive FCC is a mighty sector
• Infrared, ISM band, and amateur radio band are
  license-free
• HW2 Find out what spectrum is used for GSM,
  IS-95, 802.11b WLAN. What data rates are
  available in each system? What transmission
  characteristics makes these spectrum bands
  suitable for wireless communications?

18
Evolution of Wireless Systems

• Guglielmo Marconi invented the wireless telegraph
  in 1896
• Communication by encoding alphanumeric characters
  in analog signal
• Sent telegraphic signals across the Atlantic
  Ocean
• First public mobile (car-based) telephone system
  (MTS) introduced in 1946
• Analog frequency modulation
• High power BS tower to cover 50 miles radius
• Inefficient (120K spectrum for a voice connection)

19
Evolution of Wireless Sys. (Contd)

• Improved mobile telephone system (IMTS) developed
  in 1960
• Full duplex services and direct-dialing
• 23 FM channels with BW reduced to 25-30 KHz
• Cellular concept
• Exploits the attenuation of radio signal with
  distance to achieve frequency reuse.
• originally proposed by D. H. Ring in 1947
• Bell Labs began work on cellular telephone system
  in the late 1960s.

20
Evolution of Wireless Sys. (1G)

• Handoff was not solved until the development of
  microprocessor, efficient remote-controlled RF
  synthesizer, and switching center.
• 1G Cellular System
• Designed in 1970s, deployed in early 1980s
• Analog, 42 control channels, 790 voice channels
• Handoff performed at BS based on received power
• AMPS in US TACS in part of Europe NTT in Japan
  C450 in West German, and NMT in some countries.
• Became highly popular AMPS still popular in US!

21
Evolution of Wireless Sys. (2G)

• 2G Systems
• Digital cellular telephony
• Modest data support, incompatible
• GSM a common TDMA technology for Europe claim
  about 3/4 of subscribers worldwide.
• IS-54 and IS-136 TDMA technology in US
  compatible with AMPS
• IS-95 CDMA standardized in 1993 South Korea
  and Hong Kong deployed it in 1995 US in 1996.

22
Evolution of Wireless Sys. (2.5G)

• 2G telephony is highly successful
• Enhancement to 2G on data service
• GSM HSCSD and GPRS
• IS-95 IS-95b
• IS-136 D-AMPS and CDPD
• The improved data rate is still too low to
  support multimedia traffic
• ITU initiated 3G standardization effort in 1992,
  and the outcome is IMT-2000.

23
Evolution of Wireless Sys. (3G)

• IMT-2000 comprises several 3G standards
• EDGE, data rate up to 473Kbps, backward
  compatible with GSM/IS-136
• cdma2000 (Qualcomm), data rate up to 2Mbps,
  backward compatible with IS-95
• WCDMA (Europe), introduces a new 5MHz channel
  structure data rate up to 2Mbps
• TD-SCDMA (China), CDMA in TDD fashion

24
Evolution of Wireless Sys. (4G)

• Problems of 3G systems
• Immature 3G license auction increases the
  financial burden
• What are the killer applications of 3G?
• No unified standard (political factors dominate)
• 4G systems
• Research initiated, but still not well-defined
• Data-oriented, seamless integrated with wireline
• Indoor data rate up to 100 Mbps, outdoor data
  rate up to 20Mbps.

25
Evolution of Mobile Radio Communications
26
Paradigm From 1G to Beyond 3G
27
Mobility and Information Speed of Evolving
Mobile Communication Systems
28
Trends in Wireless Commun.

• Personal Communications (Goal of mobile
  communications)
• All IP based (IPv6) (Packet switched)
• Flexible platform of complementary access
  systems( Combination of different wireless
  access systems, Hot spot services will be
  introduced by high-speed wireless access
  (gt100mbps))
• Higher system capacity (Users/Service, 5-10
  times higher than 3G)
• Higher Transmission Data rate
• Higher frequency efficiency
• More advanced multimedia applications
• Improved QoS
• Realize high levels of security and
  authentication
• Global coverage
• Global roaming

29
All IP Based
30
All IP based
Mobile InternetApplication Servers
Broadband Accesses
Network Domain
Mobile Internet Application Platforms
Mobility, Connection Control Servers
Broadband Gateway
Service Domain
OWLAN
IP Multi Radio
IP/ATM/MPLS Backbone
Mobility Gateway
Intelligent Edge
Media Gateway
31
Combination of different wireless access systems
IEEE.802.11 WLAN
PAN Bluetooth
PDMA
WPAN WLAN WWAN
32
Network of 3G beyond
33
Transmission Data Rate

• Highest data rate(3G)
• at least 144 Kb/s in a vehicular environment,
• 384 Kb/s in a pedestrian environment,
• 2048 Kb/s in an indoor office environment.
• Highest data rate (4G)
• 2Mbps in a vehicular environment,, 20Mbps in a
  pedestrian environment
• Wide Area, high velocity100Mbps
• Indoor, lower velocity1Gbps
• Evolution of transmission data rate

34
System Capacity and spectrum efficiency
Capacity 5-10 times higher than 3G Frequency
efficiency Multi-cell gt 2bits/Hz
Single-cell 510 bits/Hz
35
Drivers of 3G Beyond

• 3G evolution but difficult
• to extend to higher data rate with CDMA only
  technology
• to provide various services with different QoS
• to have enough frequency resource to accommodate
  more subscribers
• Drawback
• Low system capacity
• Low spectrum efficiency

36
Drivers of 3G Beyond
and Beyond
3G
Evolution from 2G systems
2G
37
Service Forecast for Asia Region
38
Multimedia Services

• Internet access
• Shopping/banking(e-commerce)
• Video conferencing
• Video on demand
• Telemedicine
• Distance learning

39
Ad Hoc Networks

• Self-configuring mobile networks with no
  infrastructure
• Rapid deployment and reconfiguration
• Robust to node failure
• A necessity in the battlefields of the future?
• Despite much research activity, there remain many
  significant technical challenges

40
Challenges

• Unreliable Channels (Cross Layer Design)
• Scarce Spectrum and Resource Management
• Stringent Power Budget
• Security
• Location and Routing
• Interfacing with Wired Networks
• Health Concern
• Diversified Standards and Political Struggle

41
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42
Whats Your Wireless Dream?

• Whoever, Whenever, Wherever, Whomever, Whatever
  personal communication?
• Shrinking the world into earth village?
• Outdoor classroom on lawn under trees?
• Call for help in icy storm?
• Browsing web on cozy seashore?