What You Need to Know about 802.11n
Our co-founder and CTO, Bill Kish, has been doing the networking “podcast” circuit lately.
A couple of his most recent appearances have been to discuss 802.11n in the enterprise with Nick Lippis of the Lippis Report and Keith Shaw of Network World’s Panorama.
Bill is a member of IEEE’s Project 802.11 and he discusses the ins and outs of what makes 802.11n such a great technology, as well as what its limitations are (that you probably won’t hear others in the industry mention since everyone likes to promote 802.11n as the networking panacea of the decade). He also talks about a way enterprises – SMBs and the Fortune 500 – can take advantage of 802.11n’s performance benefits without upgrading their entire networks such as using ‘n’ as a wireless mesh backbone infrastructure for 802.11g clients and access points.
The need to increase the range and performance of enterprise WLANs is on every IT administrator’s mind, because they want to provide 50 or 100 Mbps of coverage everywhere all the time so employees and visitors can easily use their laptops and dual-mode PDAs wherever they are. 802.11n addresses some of these challenges, but certainly not all.
In the Lippis podcast, Bill says 802.11n is a highly complex technology, which is both good and bad. On the one hand, the technology’s complexity means the chips companies will stay very busy and competitive for the next several years as they innovate new features and capabilities, such as multiple spatial streams, 600Mbps performance with beam-forming, etc. Also, unlike its a/b/g predecessors, .11n is scalable, so people can upgrade their networks in an evolutionary manner and plan ahead as new features become available.
There’s a lot of misperception about 'Ns' true capabilities, and companies are confused about what to do and when. There are still so many legacy a/b/g systems that can’t take advantage of 'N' Bill’s advice is to implement 802.11n in the near-term as a wireless backbone to aggregate a/b/g traffic at the speeds that ‘N’ offers. By doing this within a wireless mesh infrastructure, enterprises can extend Wi-Fi to places where cabling is prohibitive of difficult to install.
In the Network World podcast Bill dispels five critical myths about 802.11n, which he says stem from the fact that because the technology has been in development for several years and has undergone so many iterations, there’s been a lot of marketing hype and conflicting messages.
Here are the five myths Bill addresses:
- 802.11n solves all things wireless
802.11n, for many reasons, is highly susceptible to degrading performance at distance - 802.11n will offer 100 Mbps and more everywhere all the time
For many reasons, 802.11n’s performance degradation means these performance levels will be achieved SOME of the time, not all the time – the worst case can be 10% of this, and the worst case is what people remember - Interference is not an issue with .11n because it provides antenna diversity
802.11n solves the speed equation of Wi-Fi, but not reliability, so interference is still an issue - 802.11n will eclipse 802.11g as the default client access mechanism
Eventually, this is true – the question is, how long will it take for companies and consumers to fully adopt .11n products? There are still a lot of legacy systems out there, and they won’t go away any time soon - The raw capacity of 802.11n makes multimedia support over Wi-Fi a non-issue
Baloney. It's not about top line bandwidth capacity, it's about delay.
Bill says 802.11n is a great piece of technology. "It’s the product of great people who are passionate about WLANs working for many years, and it will keep people busy for several more years as the technology’s full potential is realized. We just need to be more realistic about what it IS, and what it’s NOT."
