| 108mb - 300mb wireless takes a step closer |
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| Contributed by Alan Lewis | ||
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In January this year, the IEEE's 802.11n task group approved the first draft of the official 802.11n standard. The ratified standard can be expected next year. But products are shipping now... It seems an eternity since work on ratifying an official 108mb wireless standard, 802.11n, was announced. Expected to emerge as a standard a year or two ago, it has been delayed and delayed. Finally, in January this year, the IEEE's 802.11n task group approved the first draft of the official 802.11n standard. The formal, ratified standard can be expected next year. That only a draft format has been agreed, which is subject to change before the standard is ratified, hasn't stopped wireless companies bringing "official" 802.11n products to market. The first such devices and announcements, from D-Link and Net-gear, appeared last week at CTIA D-Link stated its intention to ship 802.11n products towards the end of April, and Net-gear announced it is already shipping 802.11n routers and switches. But it is important to note, both companies products are based on the *draft* standard, which is will change between now and the formal ratification; the IEEE task group usually agrees a draft, baseline standard, subject to change as technology improves. Between the drafting of the standard and the formalisation and certification process, the technical detail can change. These changes can be documentary, minor, or sweeping in scope. Neither have any of these products received official certification from the Wi-Fi Alliance, guaranteeing they will work with other competing 802.11n products, or older 802.11a/b/g devices. When 802.11g was drafted, chip makers including Marvell, Atheros and Broadcom moved quickly to claim an early market share by introducing chip-sets based on the proposed new standard. Some chip-sets encountered problems, leaving end-users with devices that would not co-exist with devices based on other chip-sets, or even with newer devices from the same producer, based on the formalised 802.11g standard. Some users took assurance in claims that a simple firmware upgrade would ensure forward compatibility, only to be disappointed when this was not realised. The same assurances are being given this time round, but it is worthwhile examining such a claim, and a rebuttal... 802.11n uses a technology referred to as MIMO - Multiple In, Multiple Out; the chip-set utilises several antennas, allowing it to send and receive multiple signals. The signalling technology also takes advantage of the properties of radio waves, such as bouncing , to improve efficiency. This leads to greater range and throughout. Broadcom, one of the major wi-fi chip-set manufacturers, announced that it would be shipping a group of wi-fi chips, called IntensiFi, that is compatible with the 802.11n draft standard, allowed data rates of potentially 300Mbps, and compatible with the finalised 802.11n standard via a firmware upgrade. This provoked a rebuttal from Airgo Networks, which essentially owns the Mi-Mo technology. ""The only event that consumers can count on to guarantee compatibility is Wi-Fi Alliance certification," Greg Raleigh, chief executive officer of Airgo. Tellingly, Broadcom is not guaranteeing compatibility... Consequently, consumers should be wary of purchasing any product that does not bear the Wi-Fi Alliance stamp. The Alliance is expected to begin product certification early in 2007, and final ratification is expected to follow shortly afterwards. 300Mbps - it sounds fantastic. But readers should bear in mind several factors:
All that said, it is a great step forwards. Going beyond 54mb/sec 802.11g wireless, there are a multitude of incompatible products and standards. The draft 802.11n standard beings the eventual ratification, and working products, closer. And next summer, who knows - we might finally be able to work in garden on our laptops, without the need to trail Ethernet wiring! Only registered users can write comments.
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