Making the Move
Making the Move While a move to the newly ratified 802.11n standard certainly makes sense, what's less clear is how to accomplish it.Felner-Davis said that this probably isn't the best approach. "From a network planning standpoint, the properties are different," Davis-Felner explained. "You can't just take down an 11g [AP] and put in an 11n [AP] and expect the same coverage. 11n responds completely differently to obstacles. It uses multipath to augment the signal. Most of the time, you'll get better coverage [with 11n], so you could end up over-deploying." Davis-Felner said that this doesn't mean you have to replace your wireless network all at once. "You can do it piecemeal, but you should do it more mindfully. Most companies are adding 11n when they expand the network," she said. Analyst Jack Gold of J. Gold Associates said the most effective approach to 802.11n migration is to start with a survey. "You really want to do an RF [radio frequency] survey," Gold said. "N does perform a bit differently. Just dropping [802.11n APs] in where you had the old access points can work, but it's not optimal." Gold said that the RF survey is necessary because most enterprise 802.11n access points work on both the 2.4GHz band used by most Wi-Fi today and the 5GHz band used by 802.11a. He said that the two frequencies react differently to obstructions such as walls. The obstruction issue led Kimpton Hotels and Resorts to begin a migration to 11n in its guest networks. "For us, one of the primary advantages of n is the better signal propagation," said Donald O'Grady, director of technology for Kimpton. "We renovate a lot of historic properties, and 11n gives us a lot better signal propagation. We weren't really getting it for the extra bandwidth. But the signal propagation was an important feature for us. Now, we're leveraging the better bandwidth as well." Kimpton is using the newly realized bandwidth to deliver television signals to guest rooms, among other applications. O'Grady said the hotel and resort organization is using 802.11n gear from Ruckus to provide guest rooms with Wi-Fi access, and is leveraging the same infrastructure at its Philadelphia Palomar property to provide high-definition video. O'Grady said he has plans to add other 802.11n-based equipment in guest rooms, including door locks and minibars. He noted that the cost savings are substantial. "Every cable we don't install in a guest room saves $60,000 on a new building." O'Grady added that he's already seeing a return on his 802.11n investment in the form of higher guest satisfaction scores in hotels with 11n. "This year we're up to 87 percent extremely satisfied," he said. The Farpoint Group's Mathias noted that such multimission networks are the wave of the future for 802.11n. "VOIP, data, video, data collection, security, sensors, RFID-all that kind of stuff we're going to see using Wi-Fi," Mathias said. He added that the growth of 802.11n is also likely to spur the growth of cell phones with built-in Wi-Fi. "Mobile device management is an area of concern," said Mathias. "Once we get the personal device on the network, we can manage it on the network." Mathias said that T-Mobile is currently the only provider producing cell phones that also offer voice service over Wi-Fi, but thinks the other carriers will have to follow suit. "T-Mobile has been way ahead of the curve," he said. "The cellular carriers need Wi-Fi. They can't survive without it. They don't have enough licensed bandwidth for those services they want to sell." Mathias noted an additional benefit to carriers: "It gives them an ability to lock in the enterprise." While video is frequently noted as an 802.11n driver, neither Mathias nor Gold sees a rapid move to video in the enterprise. "There already is some adoption," Mathias said. "The question is when it becomes common, but it's not in 2010. Video will be a relatively small percentage of overall traffic." "I think for most enterprises, video isn't going to be that big of a draw," Gold added. "For most enterprises, it's things like VOIP or file sharing and IM." Video aside, 802.11n is a standard that is well worth embracing. "People will be very glad they have 11n in the out years," Mathias said. In the meantime, he noted, even a mix of Wi-Fi gear will benefit from 802.11n: "It's a better g than g." Contributing Analyst Wayne Rash can be reached at email@example.com.
In some cases, network managers are simply replacing old Wi-Fi access points with 802.11n APs, putting the new devices in the same place and with the same network infrastructure as the old.