
236af23356fe3a305177cda29bbef1a9.ppt
- Количество слайдов: 34
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 Multi. Frequency) 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 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 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 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 n Peter Brierley, Professor, Collin County Community College, brierley. peter@gmail. com 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