On September 28, 2012, Crown Castle entered into a tower leasing agreement with T-Mobile US. The agreement leased 7,200 radio towers for a 28-year period in exchange for $2.4 billion. After the deal ends in 2040, Crown Castle will have the option to purchase the towers for an additional $2.4 billion.  Also on October 20, 2013, Crown Castle entered into a leasing agreement with AT-T Mobility. The agreement leased 9,700 radio towers for 28 years in exchange for $4.85 billion. Crown Castle has also secured the right to acquire the towers in the future for $4.2 billion. In the future, 600 towers will be purchased directly from Crown Castle. ATT pays US$1,900 per month per site to reach the towers, with a rent increase of about 2% per year.  On December 11, 2011, Crown Castle announced an agreement to purchase NextG Networks, Inc. for nearly $1 billion. NextG had at the time of the agreement 7,000 nodes of antenna system distributed on air with 1,500 additional knots under construction as well as rights over 4,600 miles of fiber optics.
 On July 19, 2017, Crown Castle signed an agreement to buy Lightower, a fiber optic network manager in the northeastern United States, for approximately $7.1 billion. The transaction brought Crown Castle`s fiber optic network to approximately 60,000 miles.  The buyback had a significant impact on the second quarter result, reported at the end of July. Turnover increased by 3.3% and small cells increased sales by 42%. Crown Castle also announced a $3.25 billion share offering, as well as a $1.5 billion sale of early preferred shares to finance the purchase of Lightower.  In 2015, Crown Castle expanded into small cell technology to improve performance and expand the reach of its network.   The acquisition of Quanta Fiber Networks (Sunesys) in 2015 gave the company access to more than 10,000 miles of fiber optics in various subway areas such as Los Angeles, Chicago, Silicon Valley and Atlanta. Previously, in 2014, the company acquired the 24/7 Mid-Atlantic Network with more than 800 miles of fiber optics along the east coast of the United States On January 12, 2007, Crown Castle completed the acquisition of Global Signal Inc., another U.S. tour operator based in Sarasota, Florida.  On 31 August 2004, Crown Castle completed the sale of its UK subsidiary Crown Castle UK to National Grid Transco plc for more than $2 billion.   National Grid Transco plc was renamed National Grid plc in July 2005, while Crown Castle UK was renamed National Grid Wireless in October 2005.