Crown Castle International Corp. (CCIC) owns, operates and leases shared wireless infrastructure, including towers and other structures, such as rooftops (towers); distributed antenna systems (DAS)(each such system is a network of antennas for the benefit of wireless carriers and is connected by fiber to communication hubs designed to facilitate wireless communications), and interests in land under third party towers in various forms (third party land interests) (unless the context otherwise suggests or requires, references herein to wireless infrastructure include towers, DAS and third party land interests). Its core business is renting space or physical capacity (collectively, space) on its towers, DAS and, to a lesser extent, third party land interests (collectively, site rental business) through long-term contracts in various forms, including license, sublease and lease agreements (collectively, contracts). In April 2012, it acquired NextG Networks, Inc.