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 incorporate (MAC) mould, and the media coming control (MAC) management protocols and services. 3. Ad Hoc Another terminus used to describe an independent network (Basic Service run away (BSS)). 4. Extended Service Set (ESS) The use of multiple access points to extend user mobility. 5. Currently four physical layer technologies argon being used in 802.11 wireless networking. These are direct sequence spread spectrum (DSSS), frequency hopping spread spectrum (FHSS), infrared, and incorporeal frequency division multiplexing (OFDM). 6. 802.11 DSSS implements 14 channels (each consuming 22MHz) oer approximately 90MHz of RF spectrum in the 2.4GHz ISM (industrial, scientific, and medical) band. 7. In frequency hopping s pread spectrum (FHSS), the transmit signal frequency changes based on a pseudorandom sequence. Pseudorandom means the sequence appears to be random anyways in fact does repeat, typically after some coherent period of time. FHSS uses 79 channels (each 1MHz wide) in the ISM 2.4GHz band. 8.

FHSS requires that the transmission 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 partitioning 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 input Multiple Output (MIMO) uses a technique called space-division multiplexing, where the data grow forth is split into multiple parts called spacial streams. The dissimilar spatial streams are transmitted using separate antennas. With MIMO, duplicate the spatial streams doubles the effective data rate. 12. 802.11n only...If you want to postulate a full essay, order it on our website: OrderCustomPaper.com

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