Because of their limited range, Wi-Fi hotspots can compete with cellular data services like EDGE and 1X only in high-traffic areas today. Not meant for wide-area coverage, Wi-Fi can’t reach much more than 500 metres — less in buildings where walls get in the signal’s way.
But a related wireless
technology called Wi-Max, also known as 802.16, goes farther than Wi-Fi. Besides handling a theoretical bandwidth of 56 Megabits per second (Mbps) — comparable to the newer 802.11g standard and about a five-fold improvement over the widely implemented 802.11b — it can reach about 50 kilometres.
The 802.16 standard is still being finalized, says Tom Elliott, vice-president of consulting at research firm Strategy Analytics, Inc., in Boston. The first commercial products that use it should appear toward the end of this year.
One of Wi-Max’s first uses will probably be backhauling Wi-Fi access points. Today, each hotspot needs a wired connection to the Internet. Running these wires can be costly, slowing down hotspot deployment, and often the backhaul connection is a bottleneck that forces operators to throttle back the speed of the Wi-Fi network itself.
Wi-Max could solve those problems. Used to connect multiple hotspots back to one Internet connection, it is fast enough to avoid backhaul bottlenecks, and has enough range to support hotspots all over a downtown area.
Dayed-Amr El-Hamamsy is president and chief executive of Calgary-based Wi-LAN Inc., which is a member of the industry consortium promoting Wi-Max. He says there are already Wi-Fi hotspots in downtown Calgary backhauled using Wi-LAN’s existing wireless technology, which closely resembles the emerging standard.
Over time, Wi-Max might progress from the backhaul to supplant Wi-Fi as the connection to mobile devices themselves. As more Wi-Max equipment gets installed, El-Hamamsy says, the cost will come down and more widespread use will become viable.
But there’s another way to cover wide areas with Wi-Fi. In a mesh network, the Wi-Fi access points communicate with each other. Rather than using a hard-wired connection to every access point, data can travel from access point to access point until it reaches the Internet.
Telecom Ottawa Ltd. is experimenting with a Wi-Fi mesh today. According to Dave Dobbin, chief operating officer at the broadband data and Internet access services company, a stretch of downtown Ottawa’s Elgin St. “”from the Queensway right up to the Chateau Laurier”” is now covered by a mesh of Wi-Fi hotspots.
The company — a subsidiary of Hydro Ottawa Holding Inc. — is expanding coverage this summer to a nearby area with a concentration of hotels, where Dobbin says 21 access points will cover a 10-block area. Eventually, Dobbin hopes to cover much of Ottawa with the Wi-Fi mesh. He adds says the Wi-Fi mesh matches the cellular network’s ability to hand off a connection from one access point to the next, even when the user is in a moving vehicle.
