File Name: twisted pair cable advantages and disadvantages file.zip
Cable is the medium through which information usually moves from one network device to another. There are several types of cable which are commonly used with LANs.
In some cases, a network will utilize only one type of cable, other networks will use a variety of cable types. The type of cable chosen for a network is related to the network's topology, protocol, and size.
Understanding the characteristics of different types of cable and how they relate to other aspects of a network is necessary for the development of a successful network. The following sections discuss the types of cables used in networks and other related topics. Twisted pair cabling comes in two varieties: shielded and unshielded.
Unshielded twisted pair UTP is the most popular and is generally the best option for school networks See fig. The quality of UTP may vary from telephone-grade wire to extremely high-speed cable. The cable has four pairs of wires inside the jacket. Each pair is twisted with a different number of twists per inch to help eliminate interference from adjacent pairs and other electrical devices.
The tighter the twisting, the higher the supported transmission rate and the greater the cost per foot. The standard connector for unshielded twisted pair cabling is an RJ connector.
This is a plastic connector that looks like a large telephone-style connector See fig. A slot allows the RJ to be inserted only one way. RJ stands for Registered Jack, implying that the connector follows a standard borrowed from the telephone industry.
This standard designates which wire goes with each pin inside the connector. Although UTP cable is the least expensive cable, it may be susceptible to radio and electrical frequency interference it should not be too close to electric motors, fluorescent lights, etc.
If you must place cable in environments with lots of potential interference, or if you must place cable in extremely sensitive environments that may be susceptible to the electrical current in the UTP, shielded twisted pair may be the solution.
Shielded cables can also help to extend the maximum distance of the cables. Coaxial cabling has a single copper conductor at its center. A plastic layer provides insulation between the center conductor and a braided metal shield See fig.
The metal shield helps to block any outside interference from fluorescent lights, motors, and other computers. Although coaxial cabling is difficult to install, it is highly resistant to signal interference. In addition, it can support greater cable lengths between network devices than twisted pair cable. The two types of coaxial cabling are thick coaxial and thin coaxial.
Thin coaxial cable is also referred to as thinnet. The 2 refers to the approximate maximum segment length being meters. In actual fact the maximum segment length is meters. Thin coaxial cable has been popular in school networks, especially linear bus networks. Thick coaxial cable is also referred to as thicknet. The 5 refers to the maximum segment length being meters. Thick coaxial cable has an extra protective plastic cover that helps keep moisture away from the center conductor.
This makes thick coaxial a great choice when running longer lengths in a linear bus network. One disadvantage of thick coaxial is that it does not bend easily and is difficult to install. Different types of adapters are available for BNC connectors, including a T-connector, barrel connector, and terminator.
Connectors on the cable are the weakest points in any network. To help avoid problems with your network, always use the BNC connectors that crimp, rather screw, onto the cable. Fiber optic cabling consists of a center glass core surrounded by several layers of protective materials See fig.
It transmits light rather than electronic signals eliminating the problem of electrical interference. This makes it ideal for certain environments that contain a large amount of electrical interference. It has also made it the standard for connecting networks between buildings, due to its immunity to the effects of moisture and lighting.
Fiber optic cable has the ability to transmit signals over much longer distances than coaxial and twisted pair. It also has the capability to carry information at vastly greater speeds. This capacity broadens communication possibilities to include services such as video conferencing and interactive services. The cost of fiber optic cabling is comparable to copper cabling; however, it is more difficult to install and modify. The center core of fiber cables is made from glass or plastic fibers see fig 5.
A plastic coating then cushions the fiber center, and kevlar fibers help to strengthen the cables and prevent breakage. The outer insulating jacket made of teflon or PVC. There are two common types of fiber cables -- single mode and multimode. Multimode cable has a larger diameter; however, both cables provide high bandwidth at high speeds.
Single mode can provide more distance, but it is more expensive. More and more networks are operating without cables, in the wireless mode. Wireless LANs use high frequency radio signals, infrared light beams, or lasers to communicate between the workstations, servers, or hubs. Information is relayed between transceivers as if they were physically connected.
For longer distance, wireless communications can also take place through cellular telephone technology, microwave transmission, or by satellite. Wireless networks are great for allowing laptop computers, portable devices, or remote computers to connect to the LAN.
Wireless networks are also beneficial in older buildings where it may be difficult or impossible to install cables. The two most common types of infrared communications used in schools are line-of-sight and scattered broadcast. Line-of-sight communication means that there must be an unblocked direct line between the workstation and the transceiver. If a person walks within the line-of-sight while there is a transmission, the information would need to be sent again.
This kind of obstruction can slow down the wireless network. Scattered infrared communication is a broadcast of infrared transmissions sent out in multiple directions that bounces off walls and ceilings until it eventually hits the receiver. Networking communications with laser are virtually the same as line-of-sight infrared networks. The Wi-Fi Alliance is a global, non-profit organization that helps to ensure standards and interoperability for wireless networks, and wireless networks are often referred to as WiFi Wireless Fidelity.
Since then many variations have emerged and will continue to emerge. Wi-Fi networks use the Ethernet protocol. Wireless networks are much more susceptible to unauthorized use than cabled networks. Wireless network devices use radio waves to communicate with each other.
The greatest vulnerability to the network is that rogue machines can "eves-drop" on the radio wave communications.
To minimize the possibility of this, all modern access points and devices have configuration options to encrypt transmissions. These encryption methodologies are still evolving, as are the tools used by malicious hackers, so always use the strongest encryption available in your access point and connecting devices. WPA and WPA2 WiFi Protected Access versions 1 and 2 are much better at protecting information, but using weak passwords or passphrases when enabling these encryptions may allow them to be easily hacked.
If your network is running WEP, you must be very careful about your use of sensitive passwords or other data. Three basic techniques are used to protect networks from unauthorized wireless use. Use any and all of these techniques when setting up your wireless access points:.
Florida Center for Instructional Technology. College of Education ,. University of South Florida ,. This publication was produced under a grant from the Florida Department of Education.
The information contained in this document is based on information available at the time of publication and is subject to change.
Although every reasonable effort has been made to include accurate information, the Florida Center for Instructional Technology makes no warranty of claims as to the accuracy, completeness, or fitness for any particular purpose of the information provided herein. Nothing herein shall be construed as a recommendation to use any product or service in violation of existing patents or rights of third parties. What is Network Cabling? Unshielded twisted pair.
RJ connector. Coaxial cable. BNC connector. Fiber optic cable. Fowler Ave.
Chapter 4: Cabling
It is defined as the physical medium through which the signals are transmitted. It is also known as Bounded media. Twisted pair is a physical media made up of a pair of cables twisted with each other. A twisted pair cable is cheap as compared to other transmission media. Installation of the twisted pair cable is easy, and it is a lightweight cable. The frequency range for twisted pair cable is from 0 to 3.
1/2. SHIELDED TWISTED PAIR. CABLE ADVANTAGES AND. DISADVANTAGES. PDF-STPCAAD | 56 Page | File Size 2, KB | 26 Aug, TABLE OF.
The Benefits Of Twisted Pair Cable
Physical media refers to the physical materials that are used to store or transmit information in data communications. These physical media are generally physical objects made of materials such as copper or glass. They can be touched and felt, and have physical properties such as weight and color.
In data communication terminology, a transmission medium is a physical path between the transmitter and the receiver i.
Applications of Twisted-Pair Cables
Twisted pair cabling is a type of wiring in which two conductors of a single circuit are twisted together for the purposes of improving electromagnetic compatibility. Compared to a single conductor or an untwisted balanced pair , a twisted pair reduces electromagnetic radiation from the pair and crosstalk between neighboring pairs and improves rejection of external electromagnetic interference. It was invented by Alexander Graham Bell. A twisted pair can be used as a balanced line , which as part of a balanced circuit can greatly reduce the effect of noise currents induced on the line by coupling of electric or magnetic fields. The idea is that the currents induced in each of the two wires are very nearly equal. The twisting ensures that the two wires are on average the same distance from the interfering source and are affected equally.
As a VGM stands for voice grade medium , twisted pair cable is the basis for the most internal office telephone wiring. Due to differences in the electrical characteristics, problems can occur between the pair, for example, length, resistance, capacitance. Therefore, for this reason, LAN applications will tend to use a cable of higher quality known as DGM stands for data grade medium. There are different types and categories of the twisted pair cable, but they all have the following two things in common:. The twisting of wires reduces crosstalk. Here crosstalk means, the bleeding of a signal from one wire to another and which can corrupt the signal and cause network errors.
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