Answers To Review Questions Ch 2
Answers to Review Questions Ch 2, 3
2.3 The process that takes advantage of redundancy to reduce the number of bits sent for a given piece of data is called what?
Compression.
2.6 Explain the basic principles of vector graphics and raster graphics.
In vector graphics, an image is represented as a collection of straight and curved line segments.
Simple objects, such as rectangles and ovals, and more complex objects are defined by the grouping of line segments. In raster graphics, an image is represented as a two-dimensional array of spots, called pixels, which may take on the values black or white, or may be gray scale
2.10 Define response time.
The time is takes for a system to respond to a given input.
2.11 What is considered an acceptable system response time for interactive applications and how does this response time relate to acceptable response times for Web sites?
In order to increase productivity, system response times should be kept to 2 seconds or less. For the
World Wide Web, site response time should be kept to 3 seconds or less to ensure user interest levels are kept high.
Problems
2.1 How many CD-quality music channels can be transmitted simultaneously over a 10-Mbps
Ethernet, assuming that no other traffic is carried on the same network and ignoring overhead?
The required bandwidth for each CD-quality music channel is 44100 Hz ×2 ×16 bits = 1,411,200 bps .
Assuming that no other traffic is carried on the same network, seven CD-quality music channels can be transmitted simultaneously.
2.3 A company’s telephone exchange digitizes telephone channels at 8000 smp/s, using 8 bits for quantization. This telephone exchange must transmit simultaneously 24 of these telephone channels over a communications link.
a. What’s the required data rate?
The required bandwidth for transmitting the 24 telephone channels is 1.536 Mbps.
b. In order to provide answering-machine service, the telephone exchange can store 3-minute audio messages of the same quality as that
2.3 The process that takes advantage of redundancy to reduce the number of bits sent for a given piece of data is called what?
Compression.
2.6 Explain the basic principles of vector graphics and raster graphics.
In vector graphics, an image is represented as a collection of straight and curved line segments.
Simple objects, such as rectangles and ovals, and more complex objects are defined by the grouping of line segments. In raster graphics, an image is represented as a two-dimensional array of spots, called pixels, which may take on the values black or white, or may be gray scale
2.10 Define response time.
The time is takes for a system to respond to a given input.
2.11 What is considered an acceptable system response time for interactive applications and how does this response time relate to acceptable response times for Web sites?
In order to increase productivity, system response times should be kept to 2 seconds or less. For the
World Wide Web, site response time should be kept to 3 seconds or less to ensure user interest levels are kept high.
Problems
2.1 How many CD-quality music channels can be transmitted simultaneously over a 10-Mbps
Ethernet, assuming that no other traffic is carried on the same network and ignoring overhead?
The required bandwidth for each CD-quality music channel is 44100 Hz ×2 ×16 bits = 1,411,200 bps .
Assuming that no other traffic is carried on the same network, seven CD-quality music channels can be transmitted simultaneously.
2.3 A company’s telephone exchange digitizes telephone channels at 8000 smp/s, using 8 bits for quantization. This telephone exchange must transmit simultaneously 24 of these telephone channels over a communications link.
a. What’s the required data rate?
The required bandwidth for transmitting the 24 telephone channels is 1.536 Mbps.
b. In order to provide answering-machine service, the telephone exchange can store 3-minute audio messages of the same quality as that