Wireless Communication Engineering (Fall 2004)

1. Wireless Communication Engineering(Fall 2004) Lecture 1 Professor Mingbo Xiao Sept. 23, 2004

2. 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 

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. 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?

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 (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

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: 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)

14. 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

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

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. (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.

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 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.

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. 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

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 (>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

29. All IP Based

30. 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

31. Combination of different wireless access systems IEEE.802.11 WLAN PAN Bluetooth PDMA WPAN WLAN WWAN

32. 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

33. 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

34. System Capacity and spectrum efficiency Capacity: 5-10 times higher than 3G Frequency efficiency: Multi-cell: > 2bits/Hz Single-cell: 5~10 bits/Hz

35. 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

36. Revolution from IP infrastructure IP Revolution from subscriber service expectations Drivers of 3G Beyond and Beyond 3G Evolution from 2G systems 2G

37. 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

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

42. 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?