CAS CS 101 Lecture Notes - Lecture 6: Ethernet Frame, Frequency-Hopping Spread Spectrum, Ethernet
7 Jan 2018
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Ethernet basic rules: start transmitting, listen for collisions, try about 16 times, if it keeps colliding, try again later. Wireless lans: still point to point, access point operates as a switch, receiving messages and resending them. Wireless lans use radios: radios operate in an unlicensed portion of the radio spectrums, low power consumer items don"t need a license, transmitters like wbz do, to avoid this, we use frequency hopping. Invented by heddy lamar: transmissions are channels for short amount of time, then switch. Different flows of wireless: 802. 11 a/b/n/g, etc, mostly the difference is how fast the connection is. Bluetooth: designed to replace physical wires to connect things like a mouse to a computer, now it connects all sorts of devices, has its own set of unique addresses, slower than ethernet. It"s a protocol on how to send messages between two devices (like ethernet)
