Canadian WiMAX with a Greek Flavor

If there ever was an ideal city for a MIMO-based WiMAX system, it would be Athens, Greece. Ancient buildings sit next to concrete apartment blocks, all crammed together in a maze of narrow streets. Add to that an aging copper wireline infrastructure built in the 1950s and 1960s, plus a bureaucratic regulatory system that makes getting access to the installed infrastructure practically impossible, and you can see why WiMAX has its appeal.

Craig Wireless, a Canadian wireless ISP, is trying its luck in the land of antiquity, using 3.5 GHz licenses to build a nationwide broadband wireless network as an alternative to DSL. And Craig Wireless is bringing its countryman Nortel Networks along for the ride, initially deploying a Fixed WiMAX network using base station gear from Nortel OEM partner Airspan, and eventually a full-scale Mobile WiMAX deployment using Nortel's highly touted multiple input/multiple output (MIMO) base station and smart antenna solution.

Dimitris Stavrianos, general manager of Craig Hellas, said Greece is the perfect deployment scenario for a WiMAX system. A struggle between competitive carriers and incumbents trying to unbundle the local wireless loop is ongoing, and when they do get access the aged copper plant, that makes providing DSL almost impossible. “You can't have DSL over fifty- to sixty-year-old copper,” he said. “But if you are able to install one antenna at the top of a tall building and cover a three to four kilometer area, we solve that problem.”

Craig Hellas plans to deploy 150 Nortel Mobile WiMAX systems nationwide. The initial shipments will be single input/single output base stations, but Nortel plans to upgrade them to full-fledged MIMO solutions in the second half of 2007 — just in time for Craig Hellas' commercial launch.

The deployment is Nortel's first Mobile WiMAX deployment, which may be made sweeter because the network will likely go live before Sprint's major undertaking in the U.S. Though Sprint is also pursuing a MIMO-powered network using Wave 2 WiMAX Forum-certified equipment, Nortel didn't make Sprint's final vendor cut — in part because it didn't have a handset unit to bring to Sprint's ecosystem. Sprint's network isn't expected to launch commercially until 2008, which could give Nortel time to showcase its technology while competitors Motorola, Nokia and Samsung are still building.

The project will face its share of challenges. The dual-path nature of MIMO antenna systems makes them perfect for highly mobile networks in dense urban areas, but regulations designed to protect the local GSM incumbents prevent Craig Hellas from using mobility on its networks. Although those restrictions may be lifted in the future, Craig Hellas can only support mobility within the cell itself but can't hand off from base station to base station, Stavrianos said. Consequently, Craig Hellas will start with external customer premises equipment intended to offer broadband connectivity over mobility, but the operator will be buying PCMCIA cards made by Kyocera and powered by Nortel partner Runcom's chipsets.

Even working within those confines, Craig Hellas has a larger obstacle to overcome: the 3.5 GHz spectrum. There is still a big question as to whether 3.5 GHz can support Mobile WiMAX. The band's limited propagation makes spectrum in Sprint's 2.5 GHz and particularly the sub-1 GHz frequencies much more attractive for any kind of mobile deployment of WiMAX.

But Gerry Collins, Nortel EMEA director of wireless, said, “It will be a good test environment to test MIMO technology,” he said. “We will be able to cover the cities and even the towns, but probably not the large areas in between.”