Faster Wi-Fi draft is one year old, but some concerns remain
- 01 July, 2008 08:28
The Wi-Fi Alliance celebrated the first anniversary of the 802.11n draft 2.0 certification last week, and said the faster Wi-Fi technology's "upward trajectory ... continues unabated."
Despite such confidence, adoption of the technology has been slower than some analysts and vendors had predicted a year ago. That's mostly because some early adopters have found the 802.11n radios draw more power and provide network speeds slower than expected.
"The 802.11n draft technology is still kind of a science project ... and a lot of enterprises are still hesitant to deploy what is still a nonstandard technology," said Phil Hochmuth, an analyst at Yankee Group in Boston. Some might be waiting for a fully ratified standard, expected from the Institute of Electronics and Electrical Engineers (IEEE) in March 2009, he said.
IT managers at the Interop conference in late April raised concerns about both power consumption and speed. One analyst said then that vendors are providing "confusing" information about what capabilities their products will provide.
While the alliance believes equipment sales are healthy, Hochmuth and other analysts said it's hard to track the number of shipments thus far, since most of the products appeared in the first quarter of 2008. "You hear of a lot of trials of the technology, including vendors offering free gear to entice users," he said.
Last week, 3Com added five 802.11n products to the mix, including three access points, one of which is for large business users and has a starting price of US$1,299. The 3Com line also includes products for small business users that include management features that are easy for a small company with few IT workers to set up and operate, Hochmuth said. Hochmuth said the 3Com technology is largely based on that of Trapeze Networks.
3Com joins just about every major networking vendor in offering such products. ABI Research in New York last week ranked both Aruba Networks and Meru Networks at the top of a series of vendors measuring on innovation and implementation, although ABI did not say how many devices each has shipped. ABI ranked Motorola Corp. second behind the top two, followed by Cisco Systems, Trapeze Networks and Colubris Networks.
Nearly half of all Wi-Fi chipsets sold in 2009 are expected to be based on the draft standard, with the other half based on older 802.11a/b/g technology, the alliance said. The faster draft 2.0 products deliver up to five times the speed and double the distance of products based on previous standards, the alliance claimed. The group also said 325 products from various vendors have been certified for interoperability with other draft 2.0 products. The alliance is certifying interoperability for Wi-Fi network products as well as client devices such as laptops.
Still, the concerns about power and performance raised by some IT managers and analysts are very much on the minds of vendors that are hoping to reap handsome sales with faster Wi-Fi products. The faster Wi-Fi is believed to be important in supporting high bandwidth applications such as video.
"Our sales are doing well, but I wouldn't say extremely well," said Luc Roy, vice president of the mobile enterprise unit at Siemens Enterprise Communications, which began selling 802.11n draft 2.0 products early this year.
"We were originally very bullish and thought 802.11n would surpass everything so far, but there's confusion in the market about the status of 802.11n and some customers are holding back and want to spend some time in the clarifying process," Roy said.
Siemens said it has surpassed other vendors on power consumption concerns and network performance, pointing to a validation study conducted by The Farpoint Group, an analyst and consulting firm based in Ashland, Mass. Farpoint ran a laboratory test and concluded that a Siemens AP3620 access point showed "outstanding" performance in network speed, while using minimal power.
The power complaint from some IT managers has been that the current Power over Ethernet (PoE) standard, 802.3af, won't provide sufficient wattage over a single Ethernet cable to power two different radios and a 3x3 Multiple Input Multiple Output (MIMO) antenna configuration in an 802.11n access point. (The 3x3 refers to three antennas on each of the two radios.) Farpoint noted that reducing processing in an access point, by shutting off one of two radios or reducing the 3x3 MIMO configuration to 2x3 MIMO, might draw less wattage than provided in the 802.3af standard which would be "clearly undesireable." The consulting firm added, "We see no point in installing .11n only to reap a less than optimal return on investment and the promised improved ... performance."
Analysts said they have seen IT managers string a second Ethernet cable to a new 802.11n AP to bring added PoE. One IT manager at a university couldn't afford to string more Ethernet cable and simply plugged a new AP into a wall socket nearby, said one analyst who asked not to be named. Farpoint didn't name companies that have failed to power new 802.11n APs with a single PoE Ethernet cable, but said Siemens had passed the test.
Roy said some customers seem to be waiting for a proposed PoE-plus standard that more than doubles the wattage going through a single cable. However, using PoE-plus will require a major infrastructure change that Siemens argues could be expensive and is not necessary when using their gear.
To achieve truly faster speeds with 802.11n access points, Roy said IT managers may need to put legacy 802.11a/b/g laptops and other clients on a 2.4GHz radio inside of each new 802.11n AP, while reserving the 802.11n clients for the other radio running at 5GHz, completely separate from the 2.4GHz.
Running both fast and slow clients over a single radio will slow down the faster traffic to the speed of the slower traffic, he said. "It's like a car driven on a single lane highway at 70 miles an hour, being passed by a car only doing 50 that slows down the faster car until it gets out of the way," he said.
Recognizing how complicated the implementation can be and that adjustments are needed to accommodate 802.11n for maximum performance and power conservation, Siemens has written a white paper for IT managers, "Practical Considerations for Deploying 802.11n" that details some of the tricks needed to make 802.11n function well.
Aside from such tactics, IT managers also need to take stock of wireless LAN networks in general, now that 802.11n is clearly catching on, Yankee's Hochmuth added.
"Enterprises need to look at what they use WLANs for," Hochmuth said. "With .11n coming, they need to check on what they are doing with wireless, whether it is a redundant overlay of the [wired] LAN, or whether it can be used for specific things such as network access for building visitors. They need to ask, really, has the air become the new category 5 cable?"