Mobile tower operator Crown Castle International has announced the company will buy privately held Lightower Fiber Networks for roughly $7.1 billion in cash to expand its fiber presence across urban areas of the US northeast. The deal helps expand Crown Castle's fiber network to around 60,000 route miles, giving it the ability to deploy a small cell network in top northeastern metro markets, including Boston, New York and Philadelphia. These deployments are expected to be the cornerstone of fifth-generation wireless deployments across a wide swath of the Northeast.