Networking equipment startup SpiderCloud Wireless has raised a new $35 million round amid tough competition, with a plan to upgrade its tech that makes cell phone service better indoors.

Santa Clara-based SpiderCloud’s business is focused on increasing capacity and coverage for network operators and enterprise customers who have more employees than ever using cell phones for calling instead of desk phones.

The company faces competition from carriers like AT&T, Sprint, and Verizon and other manufacturers that have already invested in femtocell technology that uses broadband connections to improve coverage indoors.

SpiderCloud has raised more than $75 million, including the new $35 million round of funding. Its last round raised totaled $25 million in Feb. 2010. Previous investors Charles River Ventures, Matrix Partners, Shasta Ventures, and Opus Capital all participated in the new round of funding. The Wall Street Journal reports that the company raised its latest round at a near $200 million valuation.

“One of the biggest issues in wireless is the lack of in-building coverage,” Bruce Sachs, a partner at Charles River Ventures, told the Journal. “There haven’t been any good solutions.”

SpiderCloud CEO Mike Gallagher told the Journal this would be the company’s final round of funding.

SpiderCloud networking image: SpiderCloud YouTube