ITM 301 Chapter Notes - Chapter 6: Wireless Lan, Frequency-Hopping Spread Spectrum, Smarttag

• School: Ryerson University
• Department: Information Technology Management
• Course: ITM 301
• Professor: Nurul Huda

Document Summary

Networks that transmit signals through the air via radio frequency (rf) waves. Wired and wireless signals share many similarities. Use of the same layer 4 and higher protocols. The nature of the atmosphere makes wireless transmission different from wired transmission. Signal travels in straight line directly from transmitter to receiver. When obstacles are in a signal"s way, the signal may: Signal weakens; moves away from transmission antenna. Correcting signal attenuation; amplify or repeat the signal from a closer broadcast point called a range extender. More vulnerable to noise; no wireless conduit, shielding. Signal-to-noise ratio (snr) = proportion of noise to the strength of a signal. Frequency bands (5. 1 ghz, 5. 3 ghz, 5. 4 ghz, 5. 8 ghz) 24 unlicensed bands, each 20 mhz wide. Operates in the radio band of 2. 4 ghz to 2. 485 ghz. Hops between frequencies within that band (called frequency hopping) Requires close proximity to form a connection. Before two bluetooth devices can connect, they must be paired.