17. Frequency Spectrum Low Frequency High Frequency Radio Frequency Coaxial Cable MHz Satellite Transmission Microwave MHz Voice KHz
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23. Limiting Factors on Communication Speed Communication Speed Bandwidth Technology
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25. Speed Dependency on Bandwidth and Technology Medium 1 example can be shielded twisted pair and medium 2 example can be fiber. Medium 1 Technology Medium 2 Higher Bandwidth
53. Unicode Advantage in WWW Transmissions Client Tamil Web Site Internet Explorer Browser retrieving Tamil pages on a client supporting Unicode. Tamil pages are transmitted in their binary encoded form. Site created using all the tools such as the MS-IIS.
54. Transmission of Tamil Pages as Images on WWW Client Tamil Web Site Internet Explorer Browser retrieving Tamil pages similar to images. Binary image transmission of Tamil pages. Web pages scanned and stored as images.
55. Using Downloaded Fonts to Host and Transmit Tamil Pages Client Tamil Web Site Internet Explorer retrieving Tamil pages. Site created with tools such as MS-IIS. Download and install the Tamil fonts. Binary encoded form. Bandwidth requirements are low.
59. Digitization of Audio: Pulse Amplitude Modulation (PAM) Audio 9 8 7 6 7 9 Digital Signals must further be encoded into binary signals for computer processing and transmission. Sampling Interval
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61. Binary Encoding of Signals in Pulse Code Modulation (PCM) 9 8 7 6 5 6 1001 1000 0111 0110 0101 0110 The integer numbers have effectively been coded into zeros and ones. The ones and zeros now contain the audio information encoded in a form that could be processed by a computer. PCM
68. Factors Affecting Quality Number of bits used for binary encoding. Example: 4 bits allow 16 amplitude variations to be represented. 9 8 7 6 7 9 Sampling Interval
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70. Problem Representation 79 68 57 46 57 79 1/8000 Seconds or 2X4000 samples per second 8 bits are used enabling 256 amplitudes to represent the human voice which is considered to be adequate.
75. Audio Transmission In WWW Client Receive audio using Internet Explorer and a plug-in to receive the audio stream. Audio streaming requires compression. Real-time audio broadcast support using streaming server module. 28-56K bps Web Site
76. Delivery of Instruction Over the WWW Client Web Site Receive audio/video using Internet Explorer. Audio/Video streaming. Store streamed audio/ video using StreamCam. 28-56K bps
77. Internet Ramp Bandwidth Computation WWW A T1 line operating at approximately 1.354M bps can support approximately 47 connections in theory. In practice, 23 connections which is half of 47 can be supported with due consideration given to bandwidth bottlenecks.
78. Sampling Considerations In Communications Sender Receiver Digital audio transmission Adjust quality (sampling interval and bit representation) to suit bandwidth availability.
82. Analog Audio Transmission Audio Prior to Transmission Audio with Interference Transmission Audio After Filtering
83. Passage of Analog Audio Over Analog Lines Analog Audio Analog Signals Analog Signals Analog Audio Telephone Telephone
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85. Signal Passage in Digital Audio Transmission Encode Transmit Recreate Decode Audio Audio
86. A Sample Digital Audio Transmission Path Analog Audio Digital Audio ISDN Adapter ISDN Adapter Digital Audio Analog Audio Sound Card Sound Card ISDN Lines
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89. Digitized Signal Passage Over Analog Lines Encode Transmit Recreate Decode Audio Audio Limited Sampling
90. A Sample Digital Audio Transmission Path Analog Audio Digital Audio Modem Modem Digital Audio Analog Audio Sound Card Sound Card Analog PSN
91. Audio Transmission In WWW Client Web Site Receive audio using Internet Explorer and RealAudio plug-in. Audio stream over analog/digital line. Real-time audio broadcast support using RealAudio streaming server module.
113. Image Transmission Considerations Sender Receiver Adjust image to suit available bandwidth. Adjustable features are as follows. - Resolution - Color depth Adjusting the size also reduces the bandwidth requirement because of a corresponding reduction in the number of pixels required to represent the image.
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