802.11n is a specification for wireless LAN (WLAN) communications. 802.11n was the next of IEEE 802.11 standards after 802.11a, 802.11b, and 802.11g. An addition to the 802.11 family of standards, 802.11n will increase wireless local area network(WLAN) speed, improve reliability and extend the range of wireless transmissions.
The idea behind the 802.11n is to provide better performance and be able to keep pace with the rapidly growing speeds provided by technologies such as Ethernet. 8021.11n uses a technology called multiple input /multiple output (MIMO) and a wider radio frequency channel. It also provides a mechanism called "frame aggregation" to decrease time between transmissions. 802.11n also offers somewhat better range over earlier Wi-Fi standards due to its increased signal intensity, and it is backward-compatible with 802.11b/g gear.
Advantages of 802.11n standard:
Improvement of significant bandwidth compared to previous standards
802.11n is totally backward compatible. It can support 802.11a, b and g standards for connecting the legacy clients too.
Disadvantages of 802.11n standard:
More expensive compared to previous standards
use of multiple signals may interfere with nearby 802.11b/g based networks
With 802.11n, maximum raw data rate throughput is expected to reach as much as 600 Mbps which is more than 10 times the throughput of 802.11g.