Transmission Media

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Introduction of Transmission Medium
From the observation of “Network+ Guide to the Network” (pg75) transmission medium is a material medium that can transfer energy waves. Examples, sound use air and liquids particle as a transmission to travels. In ancient time, people transmitted information across distance by using animal, smoke, fire etc. These days, transmission medium allows the data travels through a network. With a single click, you can send the data to your destination in a short period. Transmission medium play an important role in the internet world. Data transmission can be transmitting via two type of signaling method there are analog signal and digital signal. Analog signal is continuous signal represent varying quantity which the time varying feature (variable) of the signal, the signal easy get noise interfere. Analog signal depend the result in random medication that degrade signal quality, and can cause errors. Digital signal is physical signal that represent sequence value positive voltage present a 1 and negative voltage present a 0, the signal cannot interfere by the noise. Digital signal depends on the result in bit error (Dean, 2010). (http://www.dia.unisa.it) Chapter4 transmission medium explain that transmission media basically split into two types: bounded (guided) and unbounded (unguided) media. Bounded (guided) media given a physical path (cable) to the signal to transmit, these include twisted pair, coaxial cable and optical fibre. Unbounded (unguided) media does not have physical path or medium to control or contain signals. Therefore, no boundaries present, these include microwave, satellite, radio etc. This topic mainly explains 3 bounded (guided) and 3 unbounded (unguided) media about the performance, applications, advantages and disadvantages. (Anon., n.d., p. 75)

Bounded (guided) media

Twisted Pair (TP)
From the (http://en.wikipedia.org/wiki/Twisted_pair) Twisted Pair article explain that the twisted pair is a copper wire with color- coded. Twisted pair often “bounded” into the cable. Twisted pair consist 4 pair of copper wire each pair was twisted together for the purposes of preventing unwanted electrical coupling of two copper and crosstalk. Twisted pair divides into two types: shielded and unshielded TP. UTP contain 4 pair insulated copper wire encased in a plastic sheath. In other word, UTP does not have any additional shield to protect the wire to prevent the electromagnetic interfere. However, STP is shielded by metallic substance such as foil; even some are shielded by braided copper. As a result, STP capable of noise resistant, not only that it also increase the data rate and bandwidth. (Anon., n.d.)

Image of UTP

Image of ST
Application
William Stallings Data and Computer Communication 7th Edition explain twisted pair commonly use by most ISP as a medium for Ethernet. It connected with telephone network between house and local exchange for subscriber loop. Twisted pair commonly use to LAN network for short distance data transmits. The range will not excess within a building. Twisted pair carry analog signal, its need a modem of modulate analog signal to digital signal. Amplifiers needed every 5 or 6 km until the signal reach the destination. The speed will slow down when exceed range limited. (Dean, 2010)

Performance
I learn that TIA/EIA designed seven type of cabling system to standardize twisted pair on modern network. (Dean, 2010) -Cat 3 (Category3)
-Cat 4 (category4)
-Cat 5 (category4)
-Cat 5e (Enhanced category 5)
-Cat 6 (category 6)
-Cat 6e (Enhanced category 6)
-Cat 7 (category 7)
Each cabling system each has difference speed and unique function.

Cat 3- A UTP contains four wire pair and 10-Mbps for maximum speed with 16 MHz bandwidth. Cat3 commonly use in 10-Mbps Ethernet or 4-Mbps token ring network. These day, Cat3 have been replace by Cat5 due to better cabling accommodate higher throughput. Cat 4-...
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