Comparing 802.11a with 802.11b and 802.11g

Compared to pioneer 802.11b and the more recent 802.11g, 802.11a offers some of the features of each and some unique features. Table 20.2 summarizes differences in these three wireless Ethernet solutions.

Table 20.2. 802.11a Compared to 802.11b and 802.11g

Standard	Frequency Band	Maximum Data Rate	Signal Modulation	Number of Channels (US)	Number of Non-Overlapping Channels (US)
802.11a	5GHz	54Mbps	OFDM	12	12
801.11b	2.4GHz	11Mbps	DSSS	11	3
802.11g	2.4GHz	54Mbps	OFDM	11	3

As a general rule, recent 802.11a and virtually all 802.11g hardware is more likely to support newer, recommended security features such as WPA and WPA2 than 802.11b hardware. However, some 802.11b hardware can also be upgraded to support WPA, and some early 802.11a hardware might not support newer security standards. Check with your vendor for software and firmware upgrades necessary to support a particular security feature.