Assignment # 03

1. Complete the following questions on page 112 in your book
1,2,3,4,6,9,11,14,20,23,25,30
2. Complete the following exercise on page 113 in your book
3-6
Part 1

1. How does multipoint circuit differ from a point-to-point circuit? Multipoint is also called a shared circuit. In this configuration, many computers are connected on the same circuit. This means that each must share the circuit with the others, much like a party line in telephone communication. The disadvantage is that only one computer can use the circuit at a time. When computer is sending or receiving data, all others must wait. The advantage of multipoint circuits is that they reduce the amount of cable required and typically use the available communication circuit more efficiently. Multipoint configurations are cheaper than point-to-point configurations. Point-to-point configuration is so named because it goes from one point to another (e.g., one computer to another). These are also called as dedicated circuits because they are dedicated to the use of these two computers. This type of configuration is used when the computers generate enough data to fill the capacity of the communication circuit. This can get very expensive, particularly if there is some distance between the computers.

2. Describe the three types of data flows. Circuits can be designed to permit data to flow in one direction or in both directions. There are three ways to transmit: simplex, half-duplex, and full duplex. Simplex is one-way transmission, such as that with radios and TVs. Half-duplex communication link is similar to a walkie-talkie; only one computer can transmit at a time. With full-duplex transmission, you can transmit in both directions simultaneously, with no turnaround time.

3. Describe three types of guided media. Guided media are those in which the message flows through a physical media such as a twisted pair wire, coaxial cable, or fiber-optic cable. Twisted pair wire is most commonly used. It is a pair of wires used in standard telephone wiring. They are twisted to reduce interference caused by the other twisted pairs in the same cable bundle. Twisted-pair wires go from homes and offices to the telephone company end office.
Coaxial cable is a type of guided media that is quickly disappearing. It is an insulated wire that runs through the middle of a cable. A second braided wire surrounds the insulation of the inner wire like a sheath. Used on LANs for transmitting message between devices
Even though twisted-pair is most commonly used guided media, Fiber-optic-cable also is becoming widely used. In this transmission medium that uses glass or plastic cable instead of copper wires. Instead of carrying telecommunications signals in the traditional electrical form, this technology uses high-speed streams of light pulses from lasers or LEDs that carry information inside hair-thin strands of glass called optical fibers.

4. Describe the four types of wireless media. One of the most commonly used forms of wireless media is radio; when people used the term wireless, they usually mean radio transmission. When you connect your laptop into the network wirelessly, you are using radio transmission. Radio data transmission uses the same basic principles as standard radio transmission.
Infrared transmission uses low frequency light waves to carry the air on a direct line-of-sight path between two points. This technology is similar to the technology used in infrared TV remote controls.
Microwave is an extremely high-frequency radio communication beam that is transmitted over a direct line-of-sight path between any two points. Satellite transmission through this is similar to transmission via microwave except instead of transmission involving another nearby microwave dish antenna; it involves a satellite many miles up in space.
6. Clearly explain the