Equipment manufacturers such as Cisco and Apple are continuing to release wireless hardware that meets one of the Institute of electrical and Electronics Engineers 802.11n draft standards.
Although this is primarily aimed at consumer devices for use in the home or on the road, corporate IT managers will also be interested in 802.11n because users will be interested in the higher transfer rates and ranges. But 802.11n is not really a standard yet, so if you buy 802.11n equipment today, there’s no guarantee it will work with equipment meeting the final standard — whenever that gets released. Although the working group in charge of wireless standards at the IEEE approved Draft 3 in January, the members are scheduled to meet in March and release Draft 4.0 for comments.
Though the specification is still in draft form, Apple Computer last month updated its AirPort Express mobile base station, which provides both wireless Internet connections and USB printing. It’s part of the same product family as the Airport Extreme, which is aimed at workgroups of up to 50 users. Airport Extreme boasts throughput of 140 Megabits per second (the 802.11a and g standards have an absolute maximum of 54 Mbps).
Last year, Cisco Systems launched its Aironet 1250 Series access points. Montreal-based Concordia University is in the midst of a full-scale rollout, and plans to install a network of 200 devices within two years. Concordia’s aim was to reduce congestion in areas where wireless networks get heavy use, such as student lounges.
Some users may have no choice if their 802.11g or 802.11a access points won’t handle the demand for wireless service. They may face a choice of putting up with congestion, installing proprietary equipment or using 802.11n access points with backwards compatibility to 802.11g or b cards.
The journey towards a standard has been long and arduous. In early 2006, the 802.11 task group was given proposals from three groups of vendors, known as the TGn Sync, Worldwide Spectrum Efficiency (WWiSE) and MITMOT. At the time, the IEEE has voted to change the 802.11n specification to allow throughput of up to 600 Mbps. The key technology is multiple input multiple output (MIMO) which uses several antennas to move one stream each at the same time. But the draft did not get approval from 75 per cent of its members, so eight ad hoc groups were set up to comment on different areas. Several meetings later, Draft 2 was approved in March, 2007, but the working group identified 3,076 areas that had yet to be resolved.
Fast forward to January of this year, when a meeting in Taiwan resulted in approval of 376 issues, out of 503.
So if you need a wireless network and 802.11a or g just doesn’t cut it, you may be considering pre-standard 802.11n equipment. Bear in mind there are 127 separate technical issues that still have to be resolved, so the standards body still has its work cut out for it. MIMO is a promising technology, but the industry is still a long way from a standard.