802.11n is the most significant change since the 802.11 standard emerged, with across the board changes, including the physical and MAC layers, modulation and antennas. Enabling the standard is an Herculean task, with proposals from the volunteer group meetings eliciting thousands of comments, each resolved either by a written response declining it or text explaining its inclusion.
Along with the logistics, there are the usual politics and manoeuvrings, but the Alliance began certifying draft 11n products in summer 2008, lessening the risk for developers. 11n offers an acceptable level of interoperability between 11n devices – plus backwards compatibility with 11a/b/g, so a smooth migration to 11n should be possible. The date for 802.11n ratification is September 2009, promising a dramatic leap forward in capability: up to 300 Mbps raw data rate, up to four data streams, improvements in modulation from 54Mbps to 64 Mbps at 20 MHz, plus channel bonding (taking two defined channels and combining them, doubling the data rate to 40 Mbps).
