After Cisco bought WiMax radio supplier Navini in October 2007, industry watchers have waited and wondered why the biggest networking vendor wasn't doing more with WiMax in the U.S. market. Now after Wednesday's announcement of a multi-year deal between Cisco and Clearwire, the waiting is over -- and you have to think Cisco just delivered a big wake-up call about WiMax to Silicon Valley and Wall Street in one big move.

What really made the deal big news was the inclusion of Cisco's pledge to ship a mobile WiMax end-user device before year's end. The other part of the deal, which involves Clearwire using Cisco gear in its core IP network, isn't so surprising -- in any IP network of Clearwire's size, you might be more surprised not to find Cisco gear in the wiring closets.

But by pledging to develop end-user devices, Cisco is signaling to the rest of the industry (and investors, if they are listening) that WiMax is more than a curiousity. Cisco CEO John Chambers is famous for not wanting to get into new businesses until they offer Cisco significantly large opportunities, usually in the billion-dollar range. Is WiMax the next billion-dollar business for Cisco? Thanks to Wednesday's deal, that question is now more than hypothetical.