Crown Castle International Corp. owns, operates and leases shared wireless infrastructure, including towers and other structures such as rooftops, distributed antenna systems and interests in land under third party towers in various forms. The company's core business is to provide access, including space or capacity, to its towers, and to a lesser extent, to its small cells and third party land interests via long-term contracts in various forms, including license, sublease and lease agreements. It operates its business through two segments: Crown Castle United States of America and Crown Castle Australia. The Crown Castle United States of America segment provides access to wireless carriers under long-term contracts for their antennas which transmit a variety of signals related to wireless voice and data. The Crown Castle Australia segment provides access to antenna space on towers to its customers. This segment also provides a range of services, including site maintenance and property management services for towers owned by third parties. Crown Castle International was founded by Edward C. Hutcheson Jr. and Ted B. Miller Jr. in 1994 and is headquartered in Houston, TX.