Terminology Explanation: A wireless transmission standard protocol behind 802.11a/b/g by the Wi-Fi Alliance

In the Warring States era when various WLAN technologies are intertwined, WLAN, Bluetooth, HomeRF, UWB, etc. are competing to bloom, but the WLAN of the IEEE802.11 series is the most widely used. Since the implementation of the IEEE 802.11 standard in 1997, 802.11b, 802.11a, 802.11g, 802.11e, 802.11f, 802.11h, 802.11i, 802.11j and other standards have been formulated or brewed, but WLAN still faces insufficient bandwidth and poor roaming. Convenience, weak network management, insecure system and no killer applications. Just like VoWLAN, a brand-new field in VoIP applications, although it is regarded as the most promising killer application of WLAN by industry insiders, it is difficult to develop further because of these four "nos".

In order to realize high-bandwidth and high-quality WLAN services and make the wireless local area network reach the performance level of Ethernet, 802.11n came into being.

The wonderful prospect of 600Mbps

In terms of transmission rate, 802.11n can increase the transmission rate of WLAN from the current 54Mbps provided by 802.11a and 802.11g to 300Mbps or even as high as 600Mbps. Thanks to the MIMO OFDM technology that combines MIMO (Multiple Input Multiple Output) and OFDM (Orthogonal Frequency Division Multiplexing) technology, the wireless transmission quality is improved and the transmission rate is greatly improved.

In terms of coverage, 802.11n adopts smart antenna technology. Through the antenna array composed of multiple groups of independent antennas, the beam can be dynamically adjusted to ensure that WLAN users can receive stable signals and reduce interference from other signals. Therefore, its coverage can be expanded to several square kilometers, which greatly improves the mobility of WLAN.

In terms of compatibility, 802.11n adopts a software radio technology, which is a fully programmable hardware platform, so that the base stations and terminals of different systems can achieve intercommunication and compatibility through different software of this platform, which makes the WLAN's Compatibility is greatly improved. This means that WLAN will not only realize 802.11n forward and backward compatibility, but also realize the combination of WLAN and wireless wide area network, such as 3G.

Two camps are fighting for standards

It is a pity that 802.11n is now in an embarrassing situation of "standard lag and premature product birth". The 802.11n standard has not been officially approved by the IEEE, but there are many manufacturers using MIMO OFDM technology, including D-Link, Airgo, Bermai, Broadcom, Agere, Atheros, Cisco, Intel, etc. The products include wireless network cards, wireless Routers, etc., and have been widely used in PCs and laptops.

There are two technical camps leading the 802.11n standard, namely the WWiSE (World Wide Spectrum Efficiency) alliance and the TGn Sync alliance. Both camps hope to have a priority in the next-generation wireless LAN standard battle, but the technical frameworks of the two camps have become more and more similar, for example, they both use MIMO OFDM technology, and it was reported on August 2 that, They have decided to disregard the past and jointly submitted the wireless technology version of 802.11n to the Institute of Electrical and Electronics Engineers (IEEE).

In the first half of 2007, the 2.0 draft of 802.11n has been determined, which can fully support the formal standard in the future. And IEEE expects to pass the formal standard in the first half of 2008.

On August 13th and 14th, 2009, the 2009 China Wireless LAN Forum was held at the Zhongyuan Hotel in Beijing. With the theme of "802.11n, a more convenient WLAN", the conference focused on discussing the prospect of 802.11n in technical applications.