As Unstrung notes, UK startup Iberia is going to use WiMAX equipment and unlicensed spectrum to go after the enterprise market.

Ibera has the right idea. There's money to be made in chipping away at those T1 margins. But I hope Iberia has its sights set on the tallest buildings in town as well as a little patience.

The initial WiMAX profile supports just one unlicensed band, at 5.8GHz. Although there is an enormous amount of space in this band for operators to set up shop in, the high frequency is not so good at penetrating walls, trees, etc. (at least not compared with the likes of 900MHz). At 5.8GHz, laws of physics favor line-of-site connections.

In the US, TowerStream secured the tallest buildings in Boston, New York and LA for its base stations. Founder Jeff Thompson said some of these tower deals took years to hammer out; now that he's got them, the locations give his company a tangible competitive advantage other challengers.

Granted, many of his customers do not have line-of-site connections. Jeff credits the quality of the fixed wireless equipment, which keeps improving year after year. But for time being, in the unlicensed space, if you want to be king of the fixed wireless hill, you'll need a really tall hill.