Introduction to Telecommunication

1. Introduction to Telecommunication Dr. Adeel Akram Telecom Engineering Department, UET Taxila

2. Outline • Instructor information • Motivation to study communication systems • Course descriptions and textbooks • What you will study from this course • Objectives • Coverage and schedule • Homework and exams • Background and Preview

3. Instructor Information • Office location: Telecom Engineering Department (Upstairs) • Student Contact hours: Wed. 1:00pm-1:45pm, Other time including weekend by appointment • Email: adeel.akram@uettaxila.edu.pk • Phone: 051-0947-466(o), 0323-5030-712(c) • Course website: http://web.uettaxila.edu.pk/CMS/SP2010/teITTCbs • Research interests: Wireless Networking, Sensor Networks, and Security

4. Motivations • Recent Development • Satellite Communications • Telecommunication: Internet boom at the end of last decade • Wireless Communication: next boom? iPhone • Job Market • Probably one of most easy and high paid majors recently • Intel changes to wireless, • Qualcom, Broadcom, TI, Marvell, etc. • Research Potential • One to one communication has less room to go, but multiuser communication is still an open issue. • Wimax, 3G, next generation WLAN

5. Course Descriptions • Introduction to Telecommunication • Milestones • What is the communication system? • What are the major types? • Analog or Digital • Satellite, Fiber, Wireless… • What are the major components? • How is the information transmitted? • What are the current industrial standards? • What are the state-of-art research? • Can I find a job by studying this course? • Can I find research topics?

6. Textbook and Software • Require textbook: • Telecom Crash Course • Telecom for Dummies • Recommended readings • Digital communications: J. Proakis, Digital Communications • Simon Haykin, Communication Systems, 4th edition, John Wiley and Sons, Inc. • Random process: G.R. Grimmett and D.R. Stirzaker, Probability and Random Processes • Estimation and detection: H.V. Poor, An introduction to Signal Detection and Estimation • Information theory: T. M. Cover and J. A. Thomas, Elements of Information Theory • Error correct coding: P.Sweeney, Error Control Coding

7. Homework, Exam and Participation • Homework • 2 questions per week • Exams • Three independent exams • Votes for the percentages for homework, and exams • Participations • Attendance and Feedback

8. B A Engineering System Social System Genetic System Communication System History and fact of communication

9. Communication System Components transmitter Source Coder Channel Coder Modulation D/A Source input • Digital camera: encoder; TV/computer: decoder • Camcorder • Phone channel Distortion and noise + Reconstructed Signal output Source decoder Channel decoder Demodulation A/D receiver

10. Introduction to Telecommunication What is Telecommunication ?????? Any transmission, emission, or reception of signs, signals, writing, images and sound or intelligence of any nature by wire, radio, optical or other electromagnetic systems. ITU-1989 What are the three main components in a communication system?

11. Milestones Samuel Morse: 1837 telegraph

12. Milestones Samuel Morse: 1837 telegraph Alexander Bell:1876 telephone

13. Milestones Samuel Morse: 1837 telegraph Alexander Bell:1876 telephone Marconi: 1895 wireless telegraph not the inventor of Radio Nikola Tesla <1895 Inventor of Radio

14. Milestones Samuel Morse: 1837 telegraph Alexander Bell:1876 telephone Marconi: 1895 wireless telegraph not the inventor of Radio Nikola Tesla <1895: Inventor of Radio Lee De Forest 1907: triode vacuum tube ‘Audion’ (amplifier)

15. Milestones Samuel Morse: 1837 telegraph Alexander Bell:1876 telephone Marconi: 1895 wireless telegraph not the inventor of Radio Nikola Tesla <1895: Inventor of Radio Lee De Forest 1907: triode vacuum tube 1920: Commercial AM radio broadcast

16. Milestones Samuel Morse: 1837 telegraph Alexander Bell:1876 telephone Marconi: 1895 wireless telegraph not the inventor of Radio Nikola Tesla <1895: Inventor of Radio Lee De Forest 1907: triode vacuum tube 1920: Commercial AM radio broadcast 1939: First FM radio broadcast ‘Alphine New Jersey by Edwin Armstrong

17. Communication Process • Message Signal • Symbol • Encoding • Transmission • Decoding • Re-creation • Broadcast • Point to Point

18. Telecommunication • Telegraph • Fixed line telephone • Cable • Wired networks • Internet • Fiber communications • Communication bus inside computers to communicate between CPU and memory

19. Wireless Communications • Satellite • TV • Cordless phone • Cellular phone • Wireless LAN, WIFI • Wireless MAN, WIMAX • Bluetooth • Ultra Wide Band • Wireless Laser • Microwave • GPS • Ad hoc/Sensor Networks

20. Analog or Digital • Common Misunderstanding: • All transmitted signals are ANALOG ? • NO!, DIGITAL SIGNAL CAN! BE TRANSMITTED! • Analog Message: continuous in amplitude and over time • AM, FM for voice sound • Traditional TV for analog video • First generation cellular phone (analog mode) • Record player • Digital message: 0 or 1, or discrete value • VCD, DVD • 2G/3G cellular phone • Data on your disk • Your grade • Digital age: Why digital communication will prevail?

21. Channel, Bandwidth, Spectrum • Bandwidth: the number of bits per second is proportional to Bandwidth http://www.ntia.doc.gov/osmhome/allochrt.pdf

22. Electromagnetic Frequency Spectrum Frequency : f [Hertz] Wavelength:  [m] c : velocity of light: 3 x108 m/sec f  1 kHz  3 x105 m 100 kHz  3 x103 m 10 MHz  3 x101 m = 30 m 1 GHz  3 x10-1 m = 30 cm

23. Electromagnetic Frequency Spectrum

25. Power, Channel, Noise • Transmit power • Constrained by device, battery, health issue, etc. • Channel responses to different frequency and different time • Satellite: almost flat over frequency, change slightly over time • Cable or line: response very different over frequency, change slightly over time. • Fiber: perfect • Wireless: worst. Multipath reflection causes fluctuation in frequency response. Doppler shift causes fluctuation over time • Noise and interference • AWGN: AdditiveWhiteGaussian noise • Interferences: power line, microwave, other users (CDMA phone)

26. Shannon Capacity • Shannon Theory • It establishes that given a noisy channel with information capacity C and information transmitted at a rate R, then if R<C, there exists a coding technique which allows the probability of error at the receiver to be made arbitrarily small. This means that theoretically, it is possible to transmit information without error up to a limit, C. • The converse is also important. If R>C, the probability of error at the receiver increases without bound as the rate is increased. So no useful information can be transmitted beyond the channel capacity. The theorem does not address the rare situation in which rate and capacity are equal. • Shannon Capacity

27. Modulation • Process of varying a carrier signal in order to use that signal to convey information • Carrier signal can transmit far away, but information cannot • Modem: amplitude, phase, and frequency • Analog: AM, amplitude, FM, frequency, TV • Digital: mapping digital information to different constellation: Frequency-Shift Key (FSK)

28. Channel Coding • Purpose • Deliberately add redundancy to the transmitted information, so that if the error occurs, the receiver can either detect or correct it. • Source-channel separation theorem • If the delay is not an issue, the source coder and channel coder can be designed separately, i.e. the source coder tries to pack the information as hard as possible and the channel coder tries to protect the packet information. • Popular coder • Linear block code • Cyclic codes (CRC) • Convolutional code (Viterbi, Qualcom) • LDPC codes, Turbo code, 0.1 dB to Channel Capacity

29. Communication Networks • Connection of 2 or more distinct (possibly dissimilar) networks. • Requires some kind of network device to facilitate the connection. • Internet Net A Net B

30. Broadband Communication

31. OSI Model Open Systems Interconnections

32. TCP/IP Architecture • TCP/IP is the de facto global data communications standard. • It has a lean 3-layer protocol stack that can be mapped to five of the seven in the OSI model. • TCP/IP can be used with any type of network, even different types of networks within a single session.

33. What is Telecommunication? • Transmission and Networks • Milestones • Signal transmission and Media • Modulation and Demodulation • The Electromagnetic Frequency Spectrum • Bandwidth and Information Capacity • Noise Analysis

34. Communication Networks Point to point Mesh network

35. Power Measurements (dB, dBm) Pin Pout I V R What is the advantage of using dB ???????????????? http://www.allaboutcircuits.com/vol_3/chpt_1/5.html

36. Signal transmission (1) System noise and interference Transmitter Transmission mediumor Communications channel Receiver Copper cable (coax, UTP) Optical fiber cable Free space (Radio) Received Information Information source (intelligence)

37. Signal transmission (2) Low-frequency source information (analog or digital) Transmission medium (channel) Modulator and frequency up-converter Power amplifier Ampli-fier Frequency down-converter Filter High-frequency oscillator High-frequency local oscillator Receiver Transmitter

38. Transmission media and products

39. Noise Correlated noise: Related to signal Uncorrelated noise: Not related to signal

40. Noise Correlated noise Nonlinear distortion Harmonic distortion Intermodulation distortion Uncorrelated noise External Atmospheric Extraterrestrial Solar Cosmic Man-made Impulse Interference Internal Thermal noise (random movement of electrons)

41. Summary • Course Descriptions • Communication System Structure • Basic Block Diagram • Typical Communication systems • Analog or Digital • Channels • Shannon Capacity • Modulation • Communication Networks • Spectrum Allocation • Signal Transmission • Power Amplification • Noise