ECEN5553 Telecom Systems Week #1  Read [1] "Telecommunications and the IEEE Communications Society", p. 1-9 [2] "The Beginnings of Packet Switching: Some Underlying Concepts"  Exam #1 Lecture 15, 21 September (Live)  No later than 28 September (Remote DL)  Outline 7 October 2015, Lecture 22 (Live)  No later than 14 October (Remote DL)

Exams n Closed Book & Notes n 80-90% on class notes n 10-20% on Required Readings n Start Studying NOW!

Term Paper n Your Opportunity to Probe Further n Telecommunications topic of your choice n 1, ,400 words (about 7-14 pages) n Topic MUST be approved by the instructor u Submit 5-10 line Outline ASAP (Due 7 October 2015, Lecture 22) n Due 6 November 2015, Lecture 34 n Remote students: all due dates are +1 week n Visit 5553 Home Page for more details

Telecommunications n Long Distance Communications via Electro-Magnetic Means n Long Distance = Distance > Normal Voice Conversation

ECEN 5553 Telecom Systems n Core Course for M.S. Telecom Management B.S. inEngineering Management Information Systems Computer Science n Elective: Electrical Engineering n Elective: Others interested in Data, Voice, & Video Networks

Student Skill Sets... None Years Experience Technical Background None A Lot Where instructor is pitching the class.

Cheating n Don’t do it! n My idol: Judge Isaac Parker U.S. Court: Western District of Arkansas a.k.a. “Hanging Judge Parker” a.k.a. “Hanging Judge Parker”

Previous Term Paper tolls... n Fall Students in the class 11 F’s for Plagiarism 12 Major Citation Problems -20 to -40 points off n Spring 2002/Fall F's for Plagiarism n Fall 2014 (23 students) 1 Incident

Accessing OSU Library Databases PCServer OSU Based System IEEE IEEE Server verifies legal user by checking IP Source Address.

Accessing OSU Library Databases PCServer Home/Office Based System IEEE IEEE Server blocks usage due to incorrect IP Source Address.

Accessing OSU Library Databases PCServer Home/Office Based System IEEE OSU Proxy Server allows access. Maps your IP address to an OSU address. Server OSU

Required Readings n Accessing from any OSU campus? u Article links should work fine n Accessing from off campus? u You must log into the proxy server u u Sometimes the Home Page links then work u u Sometimes you have to search for article

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ISO OSI Seven Layer Model n Layer 7 Application n Layer 6 Presentation Windows API n Layer 5 Session TCP n Layer 4 TransportTCP n Layer 3 Network IP n Layer 2 Data LinkMotherboard n Layer 1 Physical Motherboard

Five Layer TCP/IP Model n Layer 5 Application Application n Layer 5 Presentation n Layer 4 Session Transport (TCP) n Layer 4 Transport n Layer 3 Network Internet (IP) n Layer 2 Data LinkData Link n Layer 1 Physical Physical

Business Version of Communications Theory: Moving Bits (OSI Layer 1) n Bandwidth... ‘...an assigned range of frequencies...’ n A sinusoid such as A*cos(2πft + θ) only has energy at a single frequency (f Hertz) n Any waveform can be constructed by adding together a bunch of sinusoids u The frequency range of the sinusoids required to do this constitutes the signal's bandwidth n Fourier Theory specifies the sinusoids required

200 Hz Cosine Wave 5/100 second plotted

Generating a Square Wave vp 5 Hz 1/3 vp 15 Hz

Generating a Square Wave /5 vp 25 Hz Hz + 15 Hz

Generating a Square Wave /7 vp 35 Hz Hz + 15 Hz + 25 Hz

Generating a Square Wave Hz + 15 Hz + 25 Hz + 35 Hz cos2*pi*5t - (1/3)cos2*pi*15t + (1/5)cos2*pi*25t - (1/7)cos2*pi*35t) 5 cycle per second "square wave" generated using first 4 sinusoids, Absolute Bandwidth = 35 Hertz.

Generating a Square Wave... 5 cycle per second square wave generated using first 50 sinusoids, Absolute Bandwidth = 495 Hertz

Generating a Square Wave... 5 cycle per second square wave generated using first 100 sinusoids, Absolute Bandwidth = 995 Hertz

Communications Theory: Moving Bits (OSI Layer 1) n Digital Signal: A finite number of symbols are transmitted. Ex) If we define a capital letter as a symbol, the alphabet is digital (26 symbols, A - Z). n Analog Signal: An infinite number of symbols are transmitted. Example) If we define the instantaneous pressure as a symbol, a voice pressure wave is an analog signal.

Example: Binary Signal n Serial Bit Stream (a.k.a. Random Binary Square Wave) u One of two possible symbols transmitted every T seconds. Here the symbol is either a positive or negative going pulse. u When two symbols are used, a symbol is known as a ‘bit’. time +1 volts 0 T If T = seconds, then this signal moves 1 Mbps.

Example:M-Ary Signal n One of M possible symbols is transmitted every T seconds. EX) 4-Ary signaling. Note each symbol can represent 2 bits. time volts +.45 T If T = seconds, then this 1 MBaud signal moves 2 Mbps

M-Ary versus Binary n Two Symbols: Binary Signaling n M Symbols: M-Ary Signaling u M is usually a power of 2 u Log 2 M bits/symbol n Baud rates same? Symbol shapes similar? If yes.. u Bandwidth required is similar u M-Ary signaling allows increased bit rate F Symbols get closer together if Power fixed F Noise and/or distortion? Receiver detection errors more likely

M-Ary signaling MMMM-Ary signaling used when BBBBandwidth is tight SSSSNR's & signal distortion tolerable PPPP(Bit Error) OK DDDDial-Up Phone Modems (3500 Hz Channel Bandwidth) 1111960's: 300 bps using binary signaling 1111980's: 14,400 bps using 128-Ary signaling 1111996: 33,600 bps using 1664-Ary signaling

Wired Signaling Generally uses square pulse symbols Generally uses square pulse symbols Symbol shape & width → system bandwidth Symbol shape & width → system bandwidth Binary → 2 possible symbols Binary → 2 possible symbols M-ary → M possible symbols M-ary → M possible symbols Can increase system bps with same bandwidth Can increase system bps with same bandwidth So long as symbol width & general shape unchanged So long as symbol width & general shape unchanged Makes receiver's life more difficult Makes receiver's life more difficult Bit Error Rate tends to increase with increasing M Bit Error Rate tends to increase with increasing M If Power Fixed If Power Fixed Can crank up power to get same BER as binary Can crank up power to get same BER as binary

Untwisted Pairs

Wired Physical Links Untwisted Pair Cabling Untwisted Pair Cabling Highly susceptible to EM interference Highly susceptible to EM interference Lousy choice for telecom systems Lousy choice for telecom systems Example: Speaker Wires, Power Lines Example: Speaker Wires, Power Lines Twisted Pair Cabling Twisted Pair Cabling Fairly resistant to EM interference Fairly resistant to EM interference Bandwidth typically in 1-2 digit MHz Bandwidth typically in 1-2 digit MHz Examples: LAN wiring, Home telephone cables Examples: LAN wiring, Home telephone cables

Twisted Pair Cables source: Wikipedia RJ45

Wired Physical Links Coaxial Cable Coaxial Cable Resistant to EM interference Resistant to EM interference Bandwidth typically in 2-3 digit MHz Bandwidth typically in 2-3 digit MHz Example: Cable TV Example: Cable TV Fiber Optic Cable Fiber Optic Cable Immune to EM interference Immune to EM interference Bandwidth in GHz to THz Bandwidth in GHz to THz

Coax Cable RG-59 flexible coaxial cable composed of: A: outer plastic sheath B: woven copper shield C: inner dielectric insulator D: copper core source: Wikipedia BNC F