Spectrum and Wired Media (ITS323, L06, Y15)

[@JanacMeena]

Tranmission Media and Spectrum • Guided = wired • We usually just care about the center frequency ○ Squaring off any curves in the wave • All frequencies are regulated ○ Radio is 93.5Mhz frequency ○ Microwave = 2.5ghz ○ Higher data rates with Coaxial than with Twisted pair (LAN Cable) Guided Media • Interference between other wires • Twisted pair enables duplex communication by having • Coaxial cables have more shielding, can be sent along longer distances ○ Two conductors along the same axis, hence co-axial ○ Outer conduct just provides resistance to interference • Optical fibre ○ More expensive, more difficult to deal with ○ No interference from electrical sources, since it’s a light signal not an electrical signal ○ Much higher bandwidth § Cost effective when high data rates are needed Decibels and Signal Strength • Signal strength is amplitude or height • Volts and watts are used for signal level • Decibels allow us to look at ratios but logarithmically • G_db=10log_10⁡〖(p_in/p_out )〗