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Wireless Communication Engineering (Fall 2004). Lecture 1 Professor Mingbo Xiao Sept. 23, 2004. Let’s Know Each Other. My Self-Introduction Course Objectives and My Wishes Your Self-Introduction (Name, Major, Reasons for taking this course, etc.)

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wireless communication engineering fall 2004

Wireless Communication Engineering(Fall 2004)

Lecture 1

Professor Mingbo Xiao

Sept. 23, 2004

let s know each other
Let’s 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 
recommended background
Recommended Background
  • Digital Communications
  • Computer Networks
  • Probability and Stochastic Processes
grading
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.

what s quiz
What’s QUIZ?
  • QUIZ is also known as POP QUIZ.
  • It’s 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?
quiz 1
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?

how about homework
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?
textbook and references
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
internet and web resources
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.*
tentative course outline
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
tentative course outline cont d
Tentative Course Outline (Cont’d)
  • 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
wireless is hot
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
introductions to wireless communications
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: 烽火狼烟、摔杯为号、铜镜反光、鸣金收兵…
  • Modern wireless communications are based on the electromagnetic field theory (Maxwell’s equations, Marconi’s invention)
introductions to wireless communications cont d
Introductions to Wireless Communications (Cont’d)

Wireless is often prior to its wired counterpart and has become an important supplement:

  • Marconi’s Wireless Telegraph  Wired Telegraph & Telephone  Cordless, Cellular Telephone, and Wireless Local Loop
  • Broadcast TV  Cable TV  Satellite TV
  • Aloha Network  Ethernet  Wireless LAN
characteristics of wireless comm
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
em spectrum for telecom
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?
evolution of wireless systems
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)
evolution of wireless sys cont d
Evolution of Wireless Sys. (Cont’d)
  • 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.
evolution of wireless sys 1g
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!
evolution of wireless sys 2g
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.
evolution of wireless sys 2 5g
Evolution of Wireless Sys. (2.5G)
  • 2G telephony is highly successful
  • Enhancement to 2Gon data service
    • GSM: HSCSD and GPRS
    • IS-95: IS-95b
    • IS-136: D-AMPS+ and CDPD
  • The improved data rate is still too lowto support multimedia traffic
  • ITU initiated 3G standardization effort in 1992, and the outcome is IMT-2000.
evolution of wireless sys 3g
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
evolution of wireless sys 4g
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.
slide26
Beyond Third

Generation

Third Generation

First Generation

Second Generation

  • Digital
  • Packet and circuit switched
  • Advanced data (multimedia) applications
  • Fast data access
  • Global coverage
  • Global roaming
  • Digital
  • Packet switched
  • All IP based (IPv6)
  • More advanced multimedia applications
  • User in control
  • Flexible platform of complementary access systems
  • High speed data
  • Improved QoS
  • Global coverage
  • Global roaming
  • Analogue
  • Circuit switched
  • Basic voice telephony
  • Low capacity
  • Limited local and regional coverage
  • Digital
  • Circuit switched
  • Voice plus basic data applications
  • Low data speed
  • Enhancements towards
    • packet switching
    • higher data rates
  • Trans-national and global roaming

Paradigm From 1G to Beyond 3G

slide28
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 (>100mbps))
  • 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
slide30
Internet

PSTN

ISDN

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

slide31
Combination of different wireless access systems

IEEE.802.11 WLAN

PAN Bluetooth

PDMA

WPAN WLAN WWAN

slide32
Services and

applications

New radio

interface

download channel

Media access system

Wireline

xDSL

DAB

DVB

IP based core network

WLAN

type

cellular

GSM

return channel:

e.g. GSM

IMT-2000

UMTS

other

entities

short range

connectivity

Network of 3G beyond

slide33
evolved 2G

2G

3G and beyond

9.6-14.4 kbps

384 kbps-20 Mbps

384 kbps-2 Mbps

100 Mbps?

64-144 kbps

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 velocity:100Mbps

Indoor, lower velocity:1Gbps

  • Evolution of transmission data rate
slide34
System Capacity and spectrum efficiency

Capacity: 5-10 times higher than 3G

Frequency efficiency: Multi-cell: > 2bits/Hz

Single-cell: 5~10 bits/Hz

slide35
Pbit/day

Subscriptions (millions)

1800

Mobile

User

150

Mobile

Fixed

Mobile Internet

Fixed Internet

1600

Non Real Time

(e.g. Internet access)

125

1400

1200

100

1000

Mobile

Internet

User

75

800

50

Real Time

(e.g. Voice)

600

400

25

200

0

1998

1999

2000

2001

0

1995

2000

2005

2010

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
slide36
Revolution from IP infrastructure

IP

Revolution from subscriber service expectations

Drivers of 3G Beyond

and Beyond

3G

Evolution from 2G systems

2G

service forecast for asia region
25

23?

Multimedia traffic increases 40%/year.

 10Mbps downstream service emerges.

 Saturation of 1G/2G services traffic.

19.8

20

Multimedia

(U:128k,D:10Mbps)

(U:128k, D:2Mbps)

(U:64k,D:384kbps)

(U/D:128kbps×n)

15%

15

Voice : Multimedia traffic ratio

 1 : 2 (in 2010)

Relative traffic value in bits (Ref: 1999)

30%

91 %

10

5.4

Subscribers ×1.5

1G/2G services

Voice (U/D: 16k, VOX0.5)

Others (<64 kbps)

5

28%

3.9

1

3.4

63%

8%

10%

1.5

0.5

0.5

9 %

0

Up

Down

Up

Down

Up

Down

Year

1999

2015

(Extrapolation)

2010

(Forecast by ITU-R TG-8/1 for Asia)

Service Forecast for Asia Region
slide38
Multimedia Services
  • Internet access
  • Shopping/banking(e-commerce)
  • Video conferencing
  • Video on demand
  • Telemedicine
  • Distance learning
ad hoc networks
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
challenges
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
what s your wireless dream
What’s 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?
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