The newest, most powerful, and most exciting (though still technically unofficial) standard from the IEEE’s 802.11 working group is named n. Whereas existing wireless standards route packets on 20MHz channels, the n standard takes advantage of a technology called multi-input multi-output (MIMO) to bond two 20MHz channels and increase the capacity to 40MHz. The n standard can deliver a maximum raw data rate of 540Mbps, and the net achievable throughput (NAT) is reportedly 10 times faster than that of 802.11g. Companies that are moving toward employing VoIP technologies in their day-to-day dealings can take advantage of this higher speed. Routers that use 802.11n are easy to spot—they have multiple antennae.
So, what are 802.11n’s drawbacks? The IEEE's 802.11n Task Group recently introduced for ratification the standard's second draft, which specifies implementing good-neighbor technology. The 802.11n standard’s 2.4GHz channel has three non-overlapping 20MHz channels. Draft 1.0 of the 802.11n standard specified using two of those channels—which is where the standard gets its power. However, this method hogs two channels and displaces other information packets that attempt to travel on a second channel, effectively shutting down neighboring networks. To prevent 802.11n from shutting down a neighbor's Wi-Fi, the Task Group introduced specifications in Draft 2.0 that cause 802.11n to reduce its use to just one 20MHz channel if the other two channels have traffic from another Wi-Fi network. The disadvantage of this change is that 802.11n users might find that they’ve lost the performance boost they paid for when they upgraded.