Q8. What is transmission Media? Explain all types of Guided Media with parts.
Answers
A transmission medium is something that can mediate the propagation of signals for the purposes of telecommunication
There four basic types of Guided Media :
1.Open Wire
2.Twisted Pair
3.Coaxial Cable
4.Optical Fiber
Answer:
Many different types of media can be used for the physical layer. For example, telephone twisted pair, coax cable, shielded copper cable and fiber optics are the main types used for LANs. Different transmission techniques generally categorized as baseband or broadband transmission may be applied to each of these media types.
Explanation:
Guided media, which are those that provide a conduit from one device to another, include twisted-pair cable, coaxial cable, and fiber-optic cable.
Guided Transmission Media uses a "cabling" system that guides the data signals along a specific path. The data signals are bound by the "cabling" system. Guided Media is also known as Bound Media. Cabling is meant in a generic sense in the previous sentences and is not meant to be interpreted as copper wire cabling only. Cable is the medium through which information usually moves from one network device to another.
Twisted pair cable and coaxial cable use metallic (copper) conductors that accept and transport signals in the form of electric current. Optical fiber is a glass or plastic cable that accepts and transports signals in the form of light.
There four basic types of Guided Media :
- Open Wire
- Twisted Pair
- Coaxial Cable
- Optical Fiber
- OPEN WIRE
[[Image:]]Open Wire is traditionally used to describe the electrical wire strung along power poles. There is a single wire strung between poles. No shielding or protection from noise interference is used. We are going to extend the traditional definition of Open Wire to include any data signal path without shielding or protection from noise interference. This can include multiconductor cables or single wires. This media is susceptible to a large degree of noise and interference and consequently not acceptable for data transmission except for short distances under 20 ft.
- TWISTED-PAIR (TP) CABLE
Twisted pair cable is least expensive and most widely used. The wires in Twisted Pair cabling are twisted together in pairs. Each pair would consist of a wire used for the +ve data signal and a wire used for the -ve data signal. Any noise that appears on one wire of the pair would occur on the other wire. Because the wires are opposite polarities, they are 180 degrees out of phase When the noise appears on both wires, it cancels or nulls itself out at the receiving end. Twisted Pair cables are most effectively used in systems that use a balanced line method of transmission : polar line coding (Manchester Encoding) as opposed to unipolar line coding (TTL logic).
- COAXIAL CABLE
A form of network cabling used primarily in older Ethernet networks and in electrically noisy industrial environments. The name “coax” comes from its two-conductor construction in which the conductors run concentrically with each other along the axis of the cable. Coaxial cabling has been largely replaced by twisted-pair cabling for local area network (LAN) installations within buildings, and by fiber-optic cabling for high-speed network backbones.
Coaxial cable (or coax) carries signals of higher frequency ranges than twisted-pair cable. Instead of having two wires, coax has a central core conductor of solid or standard wire (usually copper) enclosed in an insulating sheath, which is, in turn, encased in an outer conductor of metal foil, braid, or a combination of the two (also usually copper).
- FIBER-OPTIC CABLE
Fiber-optic is a glass cabling media that sends network signals using light. Fiber-optic cabling has higher bandwidth capacity than copper cabling, and is used mainly for high-speed network Asynchronous Transfer Mode (ATM) or Fiber Distributed Data Interface (FDDI) backbones, long cable runs, and connections to high-performance workstations. A fiber-optic cable is made of glass or plastic and transmits signals in the form of light. Light is a form of electromagnetic energy. It travels at its fastest in a vacuum: 3,00,000 kilometers/sec. The speed of light depends on the density of the medium through, which it is traveling (the higher the density, the slower the speed). Light travels in a straight line as long as it is moving through a single uniform substance. If a ray of light traveling through one substance suddenly enters another (more or less dense), the ray changes direction. This change is called.