Cisco announced today that it is buying Starent Networks, a leading supplier of IP-based mobile infrastructure solutions, for $3.2 billion.

Starent’s infrastructure allows providers to manage access from any 2.5G, 3G, and 4G radio network. Starent makes gateways that allow “roaming between disparate networks,” such as WiMAX, CDMA, UMTS and Wi-Fi, without the user having to do anything to execute the handover.

Under the terms of the agreement, Cisco will pay $35 per share in cash in exchange for each share of Starent Networks and assume outstanding equity awards for an aggregate purchase price of approximately $2.9 billion. The acquisition has been approved by the boards of directors of both companies.

“Combining Cisco’s strength in Video and IP with Starent Networks’ leading mobile infrastructure solutions, creates a compelling portfolio of products that provides an integrated architecture to offer rich, quality multimedia experiences to mobile subscribers on 3G and 4G networks,” said Starent Networks President and Chief Executive Officer Ashraf Dahod.

Using deep-packet inspection Starent can provide an understanding of each session or subscriber transaction. Through DPI, operators can implement detailed billing schemes based on each mobile subscriber session or transaction. Starent Networks was founded in 2000 and is based in Tewksbury, Mass. with approximately 1,000 employees worldwide.

Cisco has forecast that by 2013 about 60 percent of the data traveling across mobile networks will come from videos.

Two weeks ago, Cisco made another $3 billion bet on video, placing an offer for Tandberg, a Norwegian maker of videoconferencing systems, reports the NY Times. And in March, Cisco agreed to pay $590 million for Pure Digital, a start-up that developed the popular Flip video cameras. Starent has landed major contracts, ranging from Verizon Wireless’ planned shift to Long-Term Evolution (LTE) in the U.S., to a Taiwan consortium that is deploying a nationwide WiMax network.