Exalt Communications, a company that transmits wireless data through microwave radio systems to relieve congestion on regular networks, announced today that it brought in $15 million in third-round funding to expand its “backhauling” systems globally. The Campbell, Calif. company claims that demand for its products is on the rise as mobile users increasingly swap high-bandwidth data, including text messages, photos and video.

Its licensed and license-exempt microwave radios cover from 2 to 40 GHz, allowing for scalability, low latency and native Ethernet support, Exalt says. And because they carry data directly between mobile base stations and end users, they can circumvent the regular networks — keeping their traffic at a reasonable, well-working level. Exalt’s customer base of 500 includes major carriers, mobile operators and even government agencies.

Exalt has competition in Telecom Transport Management, E-Band Communications, mesh-wireless company Strix Systems, Radwin and Siklu, all of which have their own unique backhaul offerings. Right now, there appears to be enough demand to go around, which could continue for a while if the space doesn’t become more crowded.

The recent investment round was provided by existing backer InterWest Partners, as well as Velocity Interactive Group and Trinity Ventures. In mid-January, Exalt was one of five companies that split a $21 million investment from Interwest.