Metropolitan Wi-Fi networks deliver much higher speed than cellular data and in some cases have comparable coverage, according to an independent test conducted in 14 North American cities and towns.
Many municipalities are planning or have built Wi-Fi networks to make Internet access more available in public areas and in some cases to provide an alternative to wired broadband. These networks, often available for free, are proliferating even as mobile operators roll out third-generation (3G) networks promising speeds that can match DSL.
Novarum, an independent consulting company focused on Wi-Fi, WiMax, and 3G cellular data, tested both types of networks and found Wi-Fi is generally faster where it's available. This finding may not be surprising, since even the slowest form of Wi-Fi has a theoretical maximum capacity several times that of 3G. But the Wi-Fi systems are also fairly widely available, Novarum found. Based on whether there is enough of a signal to do real work on a notebook PC, networks in Anaheim, Santa Clara and Mountain View, California, all were available in 70 percent or more of Novarum's test area. One network, in St. Cloud, Florida, was 100 percent available.
Meanwhile, cellular data networks were 86 percent available on average, but the reality wasn't as good as it looked, said Phil Belanger, managing director of Novarum, in Akron, Ohio. True 3G was available only 58 percent of the time, while in other areas the carriers filled in with lower speed services. Whereas 3G ran at 300 kilobits per second to 400kbps downstream in Novarum's tests, 2.5G alternatives offered only a fraction of that. The 2.5G version of Global System for Mobile Communications (GSM), called Enhanced Data Rates for GSM Evolution (EDGE), proved fine for using data applications on phones but inadequate for standard PC applications, Belanger said.
"If you're on a PC and trying to sync your Outlook, you're going to think your PC crashed," Belanger said.
Metro Wi-Fi delivered twice the performance of even true 3G, offering 869kbps downstream and 256K bps upstream on average, according to Novarum. One Wi-Fi network, the Toronto Hydro OneZone system, had an average of 2.2mbps downstream and 1.6mbps upstream, comparable to wired broadband, the company found. Novarum got its results while OneZone was still in test mode and only rolled out in downtown Toronto.
Two closely watched city Wi-Fi networks also came out with high marks: EarthLink's system in Philadelphia delivered 1.5mbps downstream, though it was only 50 percent available on the proof-of-concept network where the testing was done. Google's Mountain View network scored 70 percent for availability.
The lesson for cities that want metropolitan Wi-Fi is to pack in a lot of access points, Belanger said. Suburban networks need 35 to 40 nodes per square mile, and more than 100 are needed in the same space in an urban setting, according to Novarum. For example, Toronto's network had 126 nodes in a one-square-mile area.
Novarum chose sections of the network coverage areas and drove around, stopping at evenly distributed sample points, about four per square mile. They tested the networks from a parked car, using standard laptops with an integrated Wi-Fi clients. The tests were conducted over the second half of last year, Belanger said.