Low-voltage contractors who are keeping abreast of developments in their industry know wireless technology is in the process of moving to its next generation of wireless access, which will be defined by the IEEE standard 802.11n.
Of course, wireless access is not new, but 802.11n promises to bring new technologies to network users that will result in significantly increased functionality.
“This is a big step forward in the industry that will make a profound difference in networks,” said Randy Nickel, wireless manager for Intel’s Mobile Platforms Group. “This breakthrough is going to increase the performance vector throughput by up to five times.”
While there is more to 802.11n than can be fully explained here (a simple Internet search will provide plenty of good information), low-voltage contractors need to understand the cabling related topics and demands. Just as it will be logical for project owners to expect their IT directors to understand the “how it works” elements of 802.11n, so will they expect their cabling contractors to understand the cabling issues.
“A retrofit is a lot different than in a new build or ‘greenfield’ installation,” Nickel said.
A greenfield allows a relatively unobstructed design of the network, so a contractor can place wireless access points (APs) in optimum locations.
“But 802.11n has so much greater range and reliability than previous generations that a retrofit will require a lot more than just ripping down the old and putting up the new [and] thinking that happiness will follow,” Nickel said.
Test to 1 gigabit
“The first major consideration on a retrofit is to assess your cabling,” said David Veneski, Fluke Networks’ marketing manager for certification products. “You can’t install 802.11n on just any cable drop and be sure that it will work. It might, but it might not.
“The 802.11n standard, as presently drafted, specifies data rates as high as 600 Mbps,” he said. “But most preexisting Cat 5 or Cat 5e cable networks were never tested for data rates beyond 100 Mbps, so the installed base of Cat 5 or 5e copper could obstruct 802.11n connections.”
That means the preferred cable for 802.11n’s higher throughput is at least Category 6 (or better) twisted pair, which will be the logical greenfield choice. However, a Cat 6 reinstall will be out of the question for many existing networks.
“All 802.11n uplinks should be able to support 1 gigabit Ethernet (1,000BASE-T) traffic, which means that Cat 5 or 5e may actually work,” Veneski said. “But it will all come down to proper testing to determine if a network’s existing twisted-pair cabling is suitable.”
Of course, if patchcords are already in-place, the certification should be done as a channel test, rather than a permanent link test. In addition, new 802.11n devices may require upgraded Ethernet switch ports, or even replacing an entire switch.
Following a retest of an existing cable network, the next step in a retrofit to 802.11n will likely be a site survey, said Carolyn Carter, Fluke Networks’ product manager for wireless networking.
“You can do a traditional walking survey, taking RSSI [received signal strength indication] measurements with laptop software, though that can be labor-intensive,” she said. “In many cases, a better way may be to use site survey software that uses predictive simulation.”
Carter said some vendors are encouraging users to skip the site survey in favor of an AP deployment.
“That is risky, though, because chances are that you’ll end up installing more APs than you need,” she said. “And commercial-grade 802.11n APs are two- to three-times more expensive than previous generations, costing about $1,300 each.”
The actual release date of the 802.11n standard is currently expected to be around the middle of 2009, but that date has already been extended multiple times.
“That does not mean that people should be thinking of 802.11n as still coming, though,” Nickel said. “It’s already here. The IEEE approval process has lagged what the industry is already doing. At this point, that approval is merely perfunctory.”
He said all of Intel’s offerings have been on the proposed 802.11n standard since July 2007.
“There are already hundreds of millions of devices out there operating on the 802.11n standard,” he said.
That means there also are many existing cable networks that will need to be tested and retrofitted for this powerful new technology that is fast becoming the industry norm. That translates to a large and profitable opportunity for telecommunications contractors that educate and equip themselves to pursue clients who will want this higher level of wireless performance.
MUNYAN is a freelance writer in Olathe, Kan., specializing in technical and business writing. He can be reached at www.russwrites.com.