802.11n Wi-Fi: 5 big questions answered

Seven years in the making and finally fully approved

802 11n Wi Fi

After seven years of development and internal bickering, the IEEE (Institute of Electrical and Electronics Engineers) recently signed off on the 802.11n wireless standard - meaning it's fully approved (or ratified) for use in wireless kit. The final amendments will be published in October.

Replacing the 802.11g specification, 802.11n is the new Wi-Fi and has been seven years in the making. It's capable of delivering greater range, improved reliability and faster data speeds thanks to the introduction of MIMO (Multiple Input, Multiple Output) technology.

1. Seven years? Why the delay?

It's hardly surprising that 801.11n took so long to get to the finishing line. According to the IEEE, over 400 equipment and silicon suppliers, service providers, systems integrators, consultant organisations and academic institutions have been involved in developing the specification.

Bruce Kraemer, Chair of the IEEE Wireless LAN Working Group, also points out that: "when [the IEEE] started in 2002, many of the technologies addressed in 802.11n were university research topics and had not been implemented."

A small format war also didn't help. Come 2004, the 802.11 Task Group (TGn) had received 32 different proposals to define the core specifications of the 802.11n standard. These were whittled down to two rival proposals by 2005.

In the blue corner, the WWiSE consortium gathered together the likes of Airgo Networks, Broadcom, Motorola, Nokia and Texas Instruments. While in the red corner, the TGn Sync group was backed by tech heavyweights such as Intel, Atheros Communications, Samsung, Sony, Philips and Panasonic.

The two groups merged their specification into an 802.11n Draft 1.0 a year later (albeit with 12,000 nit-picking comments).

2. Haven't we been using 802.11n for the past few years?

Yes. And no. Manufacturers have always been keen to release faster wireless products. 802.11g, for example, was unofficially pushed beyond its 54Mbps limit with channel-bonding 'Super G' and 'Turbo' products, which accelerated performance to 108Mbps.

Devices such as Belkin's G Plus MIMO pushed this still further.

The first 802.11n-inspired products appeared in 2006 under the 'Pre-N' banner. These models based on Draft 1.0 of the 802.11n standard.

Belkin mimo router

MIMO: The technology originally appeared in souped-up 802.11g products like this Belkin router

Draft 1.0, however, was criticised for its poor throughput and there were interoperability issues between products from different manufacturers that scared off many consumers.

A more stable Draft 2.0 specification was issued in 2007 and this formed the basis for the 'Draft-N' and 'Wireless-N' products that have been sold to date by manufacturers including Belkin, Linksys, D-Link and Netgear.

Although the final 802.11n specification has moved onto Draft 11.0, there haven't been any significant technical changes that would have required new hardware.

3. Will my old kit work with the final standard?

Again. Yes. And no. It's a "Yes" if your router is based on Draft 2.0 of the 802.11n specification and was officially certified by the Wi-Fi Alliance. It's a "No" if your router is based on Draft 1.0 and calls itself Pre-N. According to the Wi-Fi Alliance, all existing Wi-Fi Certified Draft N wireless products will be compatible with the final standard.

Belkin n1 vision

DRAFT 2.0: Devices based on Draft 2.0 of the 802.11n specification (like the Belkin N1 Vision above) will be compatible with the final, ratified standard.

Some wireless manufacturers have also been quick to reassure consumers, announcing "full compliance" with the final version of 802.11n.

Belkin, for example, has already stated that its products currently on the market are "already compliant and do not require firmware upgrades or other software downloads". Netgear told TechRadar that its current Draft-N models "will be upgradeable via a firmware upgrade".

If you're unsure, check for the logo you can see in the picture box at the top of the page. If it's on your router or the box, you're compatible and new firmware will be released so that you're completely compliant.

4. So what's the advantage of a ratified 802.11n?

To consumers, not that much. Considering that 802.11n (Draft 2.0) products have been available for the past two years, the appearance of official 802.11n hardware in 2010 is unlikely to make much of an impact. As far as many people are concerned, they've already upgraded to 802.11n.

The optional extras included in the final specification (including packet aggregation to improve efficiency and 3x3 MIMO configurations for higher throughput) aren't deal-breakers. In contrast, the ratification of 802.11n should give business the confidence to upgrade to 802.11n – although it's worth pointing out that the Wi-Fi Alliance has already certified over 80 enterprise-grade Draft 2.0 devices.

5. What comes after 802.11n?

Using its optional 40MHz mode, 802.11n is capable of delivering throughput of up to 600Mbps by combining four 150Mbps data channels. It's easily fast enough for the demands of streaming video. But research is already under way on Gigabit wireless networking technology to replace it.

The High-Throughput Study Group (HTSG) that dreamt up 802.11n has since birthed two new groups.

These are working on future standards using frequencies below 6GHz (dubbed 802.11ac) and in the 60GHz band (802.11ad). These wireless technologies could potentially double the performance and range of 802.11n. But given the IEEE's track record, we might have to wait until 2016...

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