Wednesday, January 22, 2014

Wireless Networking Ch4

Section 4-2 1. 1. A cost-effective networking media for use in beas that ar difficult or too costly to wire. 2. User mobility in the workplace. 2. The IEEE 802.11 WLAN standard defines the physical (PHY) floor, the medium bother lead (MAC) form, and the media main course control (MAC) management protocols and services. 3. Ad Hoc Another end point used to describe an independent network (Basic Service disgorge (BSS)). 4. Extended Service Set (ESS) The use of multiple access points to extend user mobility. 5. Currently four physical layer technologies be being used in 802.11 wireless networking. These are direct sequence spread spectrum (DSSS), absolute frequency hopping spread spectrum (FHSS), infrared, and pert frequency division multiplexing (OFDM). 6. 802.11 DSSS implements 14 channels (each consuming 22MHz) all over approximately 90MHz of RF spectrum in the 2.4GHz ISM (industrial, scientific, and medical) band. 7. In frequency hopping spread spectrum (FHSS), the transmit signal frequency changes based on a pseudorandom sequence. Pseudorandom means the sequence appears to be random also in fact does repeat, typically after some broad period of time. FHSS uses 79 channels (each 1MHz wide) in the ISM 2.4GHz band. 8. FHSS requires that the transmittal and receiving units know the hopping sequence (the order of frequency changes) so that a communication link can be established and synchronized. 9. The 802.11a equipment operates in the 5GHz range. The modulation technique used is Orthogonal Frequency naval division Multiplexing (OFDM) 10. a. 802.11b - 11 Mbps b. 802.11a - 54 Mbps c. 802.11g - 54 Mbps d. 802.11n - 200+ Mbps 11. Multiple stimulation Multiple Output (MIMO) uses a technique called space-division multiplexing, where the data burgeon forth is split into multiple parts called spacial streams. The contrasting spatial streams are transmitted using separate antennas. With MIMO, look -alike the spatial streams doubles the effec! tive data rate. 12. 802.11n only...If you want to nominate a full essay, order it on our website: OrderCustomPaper.com

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