It’s been nearly a year since the IEEE ratified the 802.11n Wi-Fi standard — a standard that bumps Wi-Fi’s theoretical performance tenfold and increases its range to three times than that of previous versions of the standard. Ever since then, the 802.11n standard has seen a swift uptake in the enterprise — even in a slumping economy — as the technology offers performance on par with wired solutions, but at a cheaper price — about 30% cheaper or more depending on how the network is constructed.
The Yankee Group predicts that the percentage of employees who connect to wireless local area networks (WLANs) will double in the next three years, from about 10% in late 2009 to more than 25% of enterprise workers by 2012. The firm further reported that about one-third of enterprises in the U.S. expect that between 21% and 50% of their employees will use WLAN as their primary access technology by 2012. To put that growth figure in perspective, the Yankee Group said that nearly half of enterprises didn’t even support WLAN three years ago.
“802.11n provides the most value for high-bandwidth applications, which the common app is video and transmission of multimedia files,” noted Dan Shey, practice director of ABI Research’s enterprise research business.
As such, Shey said health care is one market where 802.11n is gaining a significant amount of traction because of the need to transmit digital patient images, for instance.
802.11n also is becoming a hotbed for enterprises looking to deploy video surveillance. “The video surveillance market is growing across many industry verticals, and 802.11n offers the bandwidth for transmission of video back to command centers and storage centers where wired connections from cameras may not be practical or cost-effective,” Shey said.
Indeed, 802.11n promises near-wired-Ethernet speeds of up to 300 Mbps today, with 600 Mbps peak rates likely coming next year as a result of several throughput enhancements, such as MIMO (multiple-input, multiple-output) antenna technology. The standard includes other important capacity and throughput enhancements, such as the ability to use 40-megahertz-wide channels instead of 20-megahertz-wide channels, and the ability to incorporate both the 2.4 GHz and 5 GHz bands.
The incorporation of the 5 GHz band is important to video surveillance and other high-bandwidth applications, because the 2.4 GHz band is becoming highly congested due to the fact that most existing Wi-Fi equipment is tuned to the 2.4 GHz band. Shey said that if 802.11n transmissions stay on the 2.4 GHz band, then the full capacity of 802.11n equipment can’t be realized and could limit the quality of the video feed.
That’s why Craig Mathias, principal with wireless advisory firm Farpoint Group, is recommending that enterprises keep their existing Wi-Fi deployments in place at the 2.4 GHz band and then add 802.11n at the 5 GHz band for power users, because it’s much easier to use a 40-MHz channel at 5 GHz. “802.11n in the 5 GHz band will be the workhorse for the foreseeable future,” Mathias predicted.
Meanwhile, multiple vendors recently have released 802.11n products, including a router chip solution from Atheros that plays into the intense demand for video and other high-bandwidth transmissions.
While the 802.11n standard allows for multiple-stream applications that will eventually drive compliant equipment to transmit data speeds of up to 600 Mbps , most of today’s existing routers are based on the dual-stream version of the standard. This version leverages spatial multiplexing to combine two beams of data at the receiving end to double throughput — but only to 300 Mbps.
Atheros’ new solution — which is expected to be released by the third quarter — combines three streams to bump 802.11n speeds to 450 Mbps, and provides the ability to throttle back the data rates to reduce packet loss and latency. Other standards-based algorithms are used to monitor the airwaves and transmit video over “clean” channels to minimize interference. As a result, Atheros-based products can maintain sufficient throughput to support three simultaneous HD video streams, said Reynette Au, the company’s vice president of marketing and alliances.
“The three-stream capability allows not only increased bandwidth, but it’s smart about what it does in terms of taking advantage of the 2.4 GHz and 5 GHz band,” Au said. “We think that kind of application is what the enterprise wants to support, because the demand to run multiple applications is increasing. … It’s safe to say that the enterprise consumes a lot of resources, with video being the biggest one. IP phone-calling is another one. Those types of use models are reaching the point where reliability, as well as the guaranteed bandwidth, is becoming a critical factor for a lot of people.”
Enterprise Wi-Fi vendors also are keen on keeping Wi-Fi interference to a minimum, and are beginning to differentiate themselves on that point. Smartphones, Bluetooth devices, microwave ovens and wireless video cameras, to name a few, tend to pollute the spectrum.
“Wi-Fi is so attractive as an Internet delivery mechanism because the spectrum is free,” Au said. “But it can get cluttered and dirty. It’s going to put the burden on Wi-Fi technology developers to find ways to manage the frequencies, such as running the appropriate applications in the appropriate bands.”
Recently, Cisco introduced 802.11n access points that the company says are capable of identifying, classifying, locating and mitigating signal interference within an enterprise. The Aironet 3500 series includes a technology Cisco calls CleanAir, which consists of an application-specific integrated circuit (ASIC) in the access point that uses system-level intelligence to generate detailed interference information.
“IT is struggling to make infrastructure mission-critical. Right now it’s best effort. IT managers don’t have the expertise to make it mission-critical,” said Chris Kozup, senior manager of mobility solutions with Cisco, the vendor with the biggest WLAN market share. “Enterprises are making investments in 802.11n because they want the performance, yet they are struggling to deliver full performance.”
In April, Aruba Networks introduced a software-based RF spectrum analyzer called the Spectrum Analysis Module, which works with all Aruba 802.11n access points. The analyzer identifies potential sources of interference and jamming that would impact network reliability and isolates RF problems in real-time, with the ability to scan the 2.4 and 5 GHz radio bands.
And Ruckus Wireless offers its BeamFlex smart-antenna technology to mitigate interference by sending Wi-Fi signals only in the intended direction. In addition, Ruckus improves 802.11n’s “channel bonding” techniques, which combine two, 20 MHz channels into a single wideband 40 MHz channel for increased throughput. With BeamFlex, channel-bonding effectiveness is increased four-fold, the company said.
Competition is fierce in the enterprise WLAN market, with some 15 enterprise-class vendors currently in the space. As such, analysts expect a host of vendors to come to market with interference and management solutions, which is how these companies are differentiating themselves, Mathias said.
“There is more than enough business to go around,” Mathias said. “We’re at the edge of the all-wireless enterprise.”