Guided(Bounded) Communication Media
Management Information System
Guided(Bounded) Communication Media:
In guided communication media,information is transmitted over a closed path such as physical wire.So,they are also called wired communication media or bound communication media.For e.g.
- Twisted Pair Cable
- Coaxial Cable
- Optical Fiber
Twisted Pair Cable:
They are the most popular form of communication media having two insulated copper wire insulated in a spiral. It is relatively easy to setup a network using a twisted pair cable. A single twisted pair cable is capable of providing a capacity up to 1 GBPS for short distances (typically not more than 100 to 200 metres). Twisted pair makes the world’s public telephone line communication.Twisted pair cable comes in two forms:
- Shielded twisted pair (STP) Cable
- Unshielded twisted pair (UTP) Cable
Shielded Twisted Pair (STP) Cable: It consists of one or more twisted pair cables enclosed in a foll warp and woven copper shielding. Caballing is difficult than UTP. It is more expensive than UTP. The data transfer capacity of STP is from 16Mbps to 5000Mbps.
Unshielded Twisted Pair (UTP) Cable: It is most popular twisted pair cable. The quality of UTP may vary telephone form grade wire to extremely high speed cable. It is commonly used for LAN and telephone connection. It is less expensive and easier to work but it does not offer high bandwidth.The data transfer rate in UTP is up to 100 MBPS.
Twisted pair cables are cheap and easy to install and use. However their use is limited because they easily loss the data when distance exceeds beyond 100 meters.
A faster and more reliable alternative to twisted pair cable is coaxial cable. It is made up of one or more central wire rounded by thick insulation. It is used to connect the cable line in the television .It is capable of carrying 500 mbps or 15000 voice calls. Because of its particular constructions coaxial cable is much less susceptive than twisted pair cable to outside interference and information damage.It is more expensive than twisted pair cable and difficult to setup.
Coaxial cable has a copper conductor at its center. A plastic layer provides the insulation between the center conductor and braided metal shield (outer conductor). The metal shield helps to block any outside interference from fluorescent lights, motors and other computers. Although a coaxial cable is difficult to install, it is highly resistant to signal interference. It can support greater cable length between network devices than twisted pair cable.
Optical Fiber is the fastest and most reliable communication medium is optical fiber which uses a very thin glass or plastic fiber through which pulses or light travels.In the optical fiber communication, the sender converts the electrical signals to light waves and receivers convert light waves back to electrical signals. The optical fiber cable has a outer insulating jacket which is made of Teflon or PVC. At the center of fiber optic cable, a very small glass is found through which the light pulses pass. A plastic coating is used to soften the fiber center.
Optical fiber has the ability to transmit signals over much longer distances than coaxial and twisted pair cables. It carries the signals at vastly speed (as of speed of light). This capability of optical fiber makes possible services such as video conferencing and interactive services. Optical fiber has a advantage in size (one optical fiber has a diameter of a strand of a human hair), capacity exceeding more than 1400 MBPS) and quality (much greater than others). The disadvantage of optical fiber is that it is very costly and difficult to implement.