Lecture 7 - ECEN 602 F 2018(1).pdf - ECEN 602 Lecture#7...

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ECEN 602 Lecture #7 Physical Layer Part 3: Transmission Media Pierce Cantrell Department of Electrical and Computer Engineering
Outline Twisted Pair Coax Power Lines Fiber Wireless Wi-Fi, Cellular, Satellite Lecture 7 ECEN 602 2
Twisted Pair Consists of two insulated copper wires that are twisted together in a helical form. The wires are twisted together to reduce the susceptibility to interference. Twisted pair cable was patented in 1881 by Alexander Graham Bell. There are a number of different categories of twisted pair cable used for data transmission, e.g., Cat 3, Cat 5, Cat 5e, Cat 6, Cat 6A, and new ISO Cat 7 and Cat 7a with Cat 8.1 and 8.2 in development The wires have a nominal impedance of 100 Ω ±15% Category 5e cable has a wire size of 24 AWG (0.511 mm diameter); whereas, Category 6 and 6A are usually 23 AWG (0.574 mm). UTP cable that is used as horizontal cable (i.e., permanent cable or cable in walls) has solid-conductors. While stranded-conductor wire is more flexible, solid-conductor wire has less attenuation. Lecture 7 ECEN 602 3
Excerpt from US Patent 244,426, A. G. Bell, July 19, 1881 Lecture 7 ECEN 602 4
Why twist?
Lecture 7 ECEN 602 5
Attenuation (dB/mi) f (kHz) 19 gauge 22 gauge 24 gauge 26 gauge 6 12 3 9 15 18 21 24 27 30 1 10 100 1000 Twisted Pair - Attenuation vs. Frequency Lecture 7 ECEN 602 6 UTP is 23 or 24 AWG House Wiring is 12 or 14 AWG
Category 3, 5, 5e, 6, 6A* Category 3 (recognized cable type in ANSI/ TIA-568-C) - This type of cable supports data rates up to 16MHz. Most common variety of UTP for a number of years starting in the late 1980s. Common applications include 4Mbps UTP Token Ring, 10BASE-T Ethernet, 100BASE-T4, and digital and analog telephone systems. Its inclusion in the ANSI/ TIA-568-C standard is for voice applications. Category 5 (was included in ANSI/ TIA/ EIA-568-B for informative purposes only) - This type of cable supports data rates up to 100 MHz.

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