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| Networking media can be defined simply as the | means by which signals (data) are sent from one computer to another (either by cable or wireless means). |
| Coaxial cable is a copper-cored cable surrounded by | a heavy shielding |
| There are several types of coaxial cable, including thicknet, thinnet, | RG-59 (standard cable for cable TV), and RG-6 (used in video distribution) |
| Coaxial thicknet is large in diameter, rigid, and | thus difficult to install, the maximum transmission rate is only 50 Mbps, and its maximum run is 500m |
| A pair of wires forms a circuit that can | transmit data. |
| The pairs are twisted to provide protection against crosstalk, the | noise generated by adjacent pairs |
| There are two basic types of twisted-pair media, | Shielded Twisted-Pair (STP) and Unshielded Twisted-Pair (UTP). |
| In Shielded Twisted-Pair (STP) cable each pair of wires is | wrapped in metallic foil to further shield the wires from noise |
| STP reduces electrical noise from | within the cable (crosstalk) and from outside the cable (EMI and RFI). |
| Unshielded Twisted-Pair (UTP) cablerelies solely on the | cancellation effect produced by the twisted wire pairs to limit signal degradation caused by Electromagnetic Interference (EMI) and Radio Frequency Interference (RFI). |
| Coaxial Cable speed and throughput is | 10-100Mbps |
| Coaxial Cable maximum cable length is | 500m |
| Shielded Twisted Pairs and Unshielded Twisted Pair speed and | throughput is 10-100Mbps |
| Shielded Twisted Pairs and Unshielded Twisted Pair maximum cable length is | 100m |
| Fiber Optic speed and throughput is | 100+ Mbps |
| Fiber Optic single mode maximum cable length is | 3000m |
| Fiber Optic multimode maximum cable length is | 2000m |
| To transmit data Fiber Optic single mode uses | one stream of laser-generated light |
| To transmit data Fiber Optic mulitmode uses | multiple streams of LED-generated light |
| UTP comes in several categories that are based on the | number of wires and number of twists in those wires. |
| Category 3 is the wiring used for | telephone connections |
| Category 3 has four pairs of wires and a maximum data rate of | up to 16 Mbps |
| Category 5 and 5e are currently the most common | Ethernet cables used |
| Category 5 and 5e have four pairs of wires with a maximum data rate of up to | 100 and 1000 Mbps respectively. |
| These extra twists in Category 5e further prevent | interference from outside sources and the other wires within the cable. |
| Category 6 is similar to Category 5/5e except that a | plastic divider separates the pairs of wires to prevent crosstalk |
| RS-232 supports a connection between | two devices over a single cable. |
| Modems, mice, and serial printers are designed to connect to | the RS-232 port. |
| There are two types of RS-232 port connectors, a | 25-pin connector (DB-25) and a 9-pin connector (DB-9). |
| The most common standard for serial communication is still the | RS-232 |
| Fiber-optic refers to cabling that has a core of strands of glass or plastic (instead of copper), through which | light pulses carry signals |
| Fiber has many advantages over copper in terms of | transmission bandwidth and signal integrity over distance. |
| Fiber is more difficult to | work with and more expensive than copper cabling. |
| Wireless is an alternative method of connecting a LAN if the cost of | running cables is too high or computers need to be movable without being tethered to cables |
| Wireless networks use radio (RF), laser, infrared (IR), and | satellite/microwaves to carry signals from one computer to another without a permanent cable connection. |
| Wireless signals are | electromagnetic waves that travel through the air. |
