PHY layer data rate 11 Mbps 54 Mbps 54 Mbps 200+ Mbps Effective data rate 6 Mbps 22 Mbps 25 Mbps 100 Mbps at MAC SAP (8-13 Mbps with 11b stations) Network capacity 3 non- 3 non- 12-24 non- 6-12 non- overlapping overlapping overlapping overlapping channels channels channels dual channels Quality of service Supported supported supported supported Interference and 2.4 GHz band 2.4 GHz band 5 GHz band 2.4 or 5 GHz coexistence Interoperable with 802.11b network Technology maturity Mature Mature Mature Immature Operating range Good indoor Good indoor Line of As for 11b range range including sight or 11a including wall wall penetration operation. depending penetration on frequency penetration Scalability Small number Small number Enterprise Enterprise of users per of users scale; many scale; many per AP users per AP users per AP Table 7-4: Effective Network Capacity Comparison for 802.11a, b and g Networks Network standard and operating mode MAC SAP Network rate (Mbps overlapping capacity per channel) channels (Mbps) 802.11b 802.11g (Mixed mode - RTS/CTS) 802.11g (Non-mixed mode) 802.11a 802.11a (With 802.11h enhancements) Chapter Seven Table 7-5: Factors Affecting WLAN Operating Range Factor Impact on operating range Frequency band As described in the Section "RF Signal Propagation and Losses, p. 112", free space loss is proportional to the logarithm of operating frequency, and increases by 6.7 dB with the increase in frequency from 2.4 to 5.8 GHz. Transmitter power These two factors are grouped together since they determine and receiver the end points of the link budget, as described in the Section sensitivity "Link Budget, p. 116" Modulation and Higher data rate modulation and coding schemes are less coding scheme robust in that they require correspondingly higher received signal strength to assure accurate decoding. Other things being in equal range therefore decreases for higher data rates. Environmental Construction materials, particularly metal objects, have a factors major influence on path loss if RF signals ha