Redline Communications Inc. has grabbed another $15 million in venture funding as it waits for the official seal of approval for its fixed wireless products from the WiMAX Forum.

With fixed products expected to arrive towards the end of this year or early in 2006, the company says that much of the new money will go towards developing mobile WiMax products. "I would say the bulk of it will go towards the [802.16]e platform," says Keith Duchett, Vice President of marketing and product development.

The main difference between fixed (802.16d) and mobile (802.16e) WiMax products is that the latter specification has been enhanced so that users will be able to maintain connectivity while driving between base stations.

The rest of the funding will go to building out the firm's sales force.

Redline says that its fixed-line products are already at the Cetecom SA labs in Spain. Interoperability testing on WiMax products is due to start this month.

The six-year old startup has scored $58 million worth of funding in total. The latest round was led by Growth Fund Private Equity Group and joined by Matrix Partners and U.S. Venture Partners.