By Naomi Graychase
October 18, 2007
New reports show that Wi-Fi is performing well in citywide networks—even in Philadelphia.
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Novarum released a new set of reports this week that offer some good news to those in the metro wireless game. Based on comprehensive on-the-ground tests conducted by Novarum co-founders Phil Belanger and Ken Biba, these reports, which update last year’s numbers, and add some new cities and new indicators across the board, prove that Wi-Fi remains a viable and even appealing choice for citywide networks.
The Novarum Wireless Broadband Review (NWBR) includes surveys of networks in sixteen cities, including: Philadelphia, PA; Portland, OR; Rochelle, IL; Santa Clara, CA; Tempe, AZ; and Mountain View, CA. Each network’s wireless data services (based on Wi-Fi, WiMAX, or 3G cellular technologies) were evaluated from an end-user’s perspective. In other words, Belanger and Biba drove around the cities and measured how well their networks were actually performing in various locations. The data was gathered in the first half of 2007.
“We pick a city that has known citywide Wi-Fi and we test all the broadband services we can get there,” says Belanger. “Sometimes, we try all three major carriers—Verizon, Sprint, AT&T—but, we don’t always test all three. We test a town and pick locations within the town—at least 20—and we run the same test from the same location on all of the wireless networks of interest. We keep track of were we able to get the service or not and that constitutes our Availability ranking.
“We also test performance. We do an extensive throughput test at each location on each network. We get a lot of results and we map that into a rating (1-5) and average over all of the locations for a town. That’s what’s in the Performance column. We also look at ease of use and value, which are more subjective. Then we combine them to get the overall rating.”
The importance of clients
Among the surprising results was the significant impact that 802.11n clients have on end results for Wi-Fi users.
“This time,” says Belanger, “when we used the high power and the 11n clients, the Wi-Fi networks really worked really well. Part of the message is that depending on what client you use, it really changes your perception about the network.
“When we used an 11n client, without increasing the power at all, it’s a 20% increase in availability, and a 26% increase in performance, even on a legacy 802.11g infrastructure,” he says. “We talked to some RF experts. They said that doesn’t make sense; the radio improvements alone are not supposed to be that much better…We didn’t pick fancy equipment, either. We used a Netgear consumer 802.11n-draft device that cost about $60. That’s another part of the message: vendors will want to design client devices for 802.11n metro…A new notebook with 802.11n in it will make the metro networks seem better [to consumers], even though the network is the same.”
This year, in addition to ranking the top wireless broadband networks, Novarum issued “Best of Wireless 2007” awards. Among the winners were Toronto OneZone for Best Overall Metro Wi-Fi Service, and Earthlink Feather (in Philadelphia) for Most Improved Metro Wi-Fi Service.
“We started to re-test networks, and two of the big ones are very visible: Earthlink Feather and Google Wi-Fi Mountain View,” says Belanger. “Earthlink had a 50% increase in node density. They’ve gone up to 48 nodes per square mile on average (from 32). We tested 15 square miles; last time we only tested six. This larger area had a higher density and better service availability. Poor little Earthlink. They are still investing in [Philadelphia] and following through. They’ve said they are not finding new footprints, but are continuing to support the ones they already had. We saw evidence of substantial investment and improvement in Philadelphia.”
The reports also show that metro Wi-Fi continues to deliver twice the performance of 3G cellular data services on average.
“Cellular data is better in terms of service availability and actually doing something useful,” says Belanger. “But metro Wi-Fi delivers even higher performance than 3G. It’s more than twice as fast and sometimes five times as fast as cellular, so that’s key.”
Finding the magic number
Novarum’s research seems to indicate that one of the most crucial elements of a successful metro Wi-Fi network is node density. The magic number seems to be somewhere around 20 nodes per square mile for suburban, and between 40-50 for urban areas.
“Successful networks are putting in more and more infrastructure,” says Belanger. “Of course, this means the cost is increasing for the service provider.”
What’s in store for the future of municipal networks?
“The balance of the analysis from our Wireless Broadband Review shows that metro Wi-Fi is far from dead – it is simply entering a more rational phase of development,” said Biba. “A useful metro Wi-Fi network costs more to deploy than has been hyped, but may indeed deliver a higher quality of service at a lower cost than other wireless broadband alternatives.”
Individual reports from the Novarum Wireless Broadband Review are available at Novarum’s web site. Access to the entire review is available through an annual subscription.
Naomi Graychase is Managing Editor at Wi-FiPlanet.com.