Ch$.1$

An alternative to a LAN is simply a big timesharing system with terminals for

all users. Give two advantages of a client$-$server system using a LAN.

What are two reasons for using layered protocols? What is one possible

disadvantage of using layered protocols?

What does "negotiation" mean when discussing network protocols? Give an

example.

An image is $16001200$ pixels with $3$ bytes$/$pixel$.$ Assume the image is

uncompressed. How long does it take to transmit it over a $56-kbps$ modem

channel? Over a $1-$Mbps cable modem? Over a $10-$Mbps Ethernet? Over $100-$

Mbps Ethernet? Over gigabit Ethernet?

List two advantages and two disadvantages of having international standards

for network protocols.

Ch$.2$

What are the advantages of fiber optics over copper as a transmission

medium? Is there any downside of using fiber optics over copper?

It is desired to send a sequence of computer screen images over an optical

fiber. The screen is $25601600$ pixels, each pixel being $24$ bits. There are $60$

screen images per second. How much bandwidth is needed, and how many

microns of wavelength are needed for this band at $1\mathrm{.}30$ microns?

Is the Nyquist theorem true for high$-$quality single$-$mode optical fiber or only

for copper wire?

Why has the PCM sampling time been set at $125$ usec?

In a typical mobile phone system with hexagonal cells, it is forbidden to reuse

a frequency band in an adjacent cell. If $840$ frequencies are available, how many

can be used in a given cell?