Clearwire finding fiber alternatives

There is suddenly a race to see who can get fiber to the cell tower fastest. Verizon has committed to building carrier Ethernet to 90% of the towers used by subsidiary Verizon Wireless in five years. AT&T has been breaking down bottlenecks in its 3G network with strategic fiber deployments. And Qwest Communications has made a new commitment to work with its wireless customers to deliver fiber Ethernet services in even the most remote of sites.

None of that is fast enough for Clearwire, though. Most of those new fiber efforts are designed to support 4G networks on the horizon. Clearwire, meanwhile, is building a 4G network today, said John Saw, its chief technology officer.

“The majority of cell sites are still served by T-1 lines,” Saw said. “We know there will be choke points in the network if we use T-1s for backhaul.” So while Clearwire uses fiber where it is available and inexpensive, Saw said the vast majority of the company's network is being backhauled via point-to-point radios — to the tune of 90% of all sites in the Clearwire footprint.

While many cellular operators are patching their 3G networks by layering on T-1s, Clearwire doesn't have that option. At the bare minimum, Clearwire needs 30 Mb/s at each tower to handle the traffic from a three-sector WiMAX base station. The copper equivalent would be 20 T-1 lines. What's more, 30 Mb/s is just an average based on current traffic levels. As Clearwire grows, it expects capacity demands to grow exponentially.

“We see demand at each site easily going up to 100 Mb/s,” Saw said. “30 Mb/s is not enough. It's just enough to get started.”

Read more about what's driving mobile competitors in the 4G space in Kevin Fitchard's story, “Sprint exec on why it chose not to tackle 4G alone.” TelephonyOnline.com/3g4g