AT&T earlier Fibertower support letter to FCC for time extension on build out. Discloses Fibertower assets that were being used by AT&T in the time frame about 5 years ago and the importance to AT&T. https://wireless2.fcc.gov/UlsEntry/attachments/attachmentViewRD.jsp?applType=search&fileKey=606798297&attachmentKey=18969821&attachmentInd=applAttach