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Convergence Technology MODULE 2 - LEARNING OUTCOME 5 Describe signaling and its importance to telecommunications and differentiate various signaling techniques involved in telephony. www.convergencetechnologycenter.org DUE 402356 Voice Telephony Fundamentals What Makes the Telephone Work? • The hook switch • The Microphone • The Speaker • ECHO www.convergencetechnologycenter.org Anatomy of the phone Speaker Microphone To Wall Jack Hook Switch www.convergencetechnologycenter.org Telephone components with duplex coil and touchtone keypad Touchtone Keypad Speaker Ringer Duplex Coil Microphone To Wall Jack www.convergencetechnologycenter.org Hook Switch Component Configuration Green wire Red wire 300 Ohm Resistor 9 Volt Battery www.convergencetechnologycenter.org Telephone Carbon Microphone Vibrating Diaphragm Electric Contact Carbon Granules Wires Electric Contact www.convergencetechnologycenter.org How a speaker works Diaphragm Dust cap Suspension Magnet + Voice coil www.convergencetechnologycenter.org Voice Telephony Fundamentals Wires and Cables • Residential Cabling • The Telephone Network cabling Signaling and Transmission • Analog Signals • Digital Signals www.convergencetechnologycenter.org Dual tone dialing pad www.convergencetechnologycenter.org Entrance bridge To phones inside house Entrance Bridge Ground wire From the Central Office www.convergencetechnologycenter.org Roadside wiring concentrator Typical phone company boxe (wiring concentrator) that you have seen by the side of the road www.convergencetechnologycenter.org Residential cabling Residences www.convergencetechnologycenter.org Voice Telephony Fundamentals Waveform Sine Wave Anatomy Frequency Wavelength Amplitude Signal Phase www.convergencetechnologycenter.org Electromagnetic wave form www.convergencetechnologycenter.org Anatomy of a sine wave One cycle One Second One Hertz a t a 00 900 1800 2700 3600 V = Voltage t = time A = Amplitude One cycle per second = one Hertz www.convergencetechnologycenter.org Cycles per second One Second 1 cycle per second (1 Hz) 2 cycles per second (2 Hz) 4 cycles per second (4 Hz) www.convergencetechnologycenter.org Phase Shift www.convergencetechnologycenter.org Analog signal being digitized www.convergencetechnologycenter.org Digital Signal types Unipolar Bipolar Nonreturn to Zero Bipolar Return to Zero Manchester Differential Manchester www.convergencetechnologycenter.org The Codec Analog Phone Digital Transmission (Digital Data Lines Analog Phone Codec Analog Signal Digital Signal www.convergencetechnologycenter.org Analog to Digital to Analog Dallas Boston Central office Central Office A/D conversion D/A conversion www.convergencetechnologycenter.org Voice Telephony Fundamentals Local and Long-Distance Calling • The Protocol for Making a Phone Call • DTMF (Dual-Tone MultiFrequency) www.convergencetechnologycenter.org Dual tone dialing pad www.convergencetechnologycenter.org Voice Telephony Fundamentals Transmission Lines • Attaching Transport Devices • Circuits • Two-Wire Circuits • Four-Wire Circuits • The Effects of Attenuation When Using Two-Wire or Four-Wire www.convergencetechnologycenter.org Analog to Digital to Analog Dallas Boston Central office Central Office A/D conversion D/A conversion www.convergencetechnologycenter.org Two-wire and four-wire pairs Outer Jacket Outer Jacket Foil shield Twisted Pair Plastic insulation Braided shield Twisted Pairs Eight wire - four pair Four wire – two pair www.convergencetechnologycenter.org Two-wire circuit as used in the Local Loop www.convergencetechnologycenter.org Four-wire circuit Receive Transmit Transmit Receive Customer Site Carrier www.convergencetechnologycenter.org Voice Telephony Fundamentals •Lines and Trunks •CPE Switches •Network Switches •Channels •Virtual Circuits •Flavors of Virtual Circuits •Network Connections www.convergencetechnologycenter.org CPE lines, trunks, switches International Gateway Core Network Class 4 Switches Interexchange Trunks Class 5 Switches Local Exchange Trunks Local Loop Subscriber Lines CPE PBX PBX Residential Phones www.convergencetechnologycenter.org Business Phones Voice Telephony Fundamentals Bandwidth • Getting more out of a wire pair • Bandwidth and the Electromagnetic Spectrum • Electromagnetic Spectrum www.convergencetechnologycenter.org Electromagnetic Spectrum www.convergencetechnologycenter.org The anatomy of an analog voice channel Bandwidth of a voice channel Frequency multiplexed voice signals www.convergencetechnologycenter.org Questions: Feel free to contact the creator of this material Peter Brierley, Professor, Collin County Community College, [email protected] www.convergencetechnologycenter.org This material is based upon work supported by the National Science Foundation under Grant No. 0402356. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation