Hill AFB telephone switch requires software upgrade Published Aug. 27, 2010 By Essye Miller 75th Communications Squadron HILL AIR FORCE BASE, Utah -- 75th Air Base Wing Communications Squadron and the 500th Combat Sustainment Squadron will perform maintenance on the Hill AFB telephone switch Sept. 8 between 6 and 10 p.m.. The Hill AFB telephone switch requires a software upgrade to maintain system security compliance. Calls already in progress during the upgrade will not be affected. Users attempting to place calls during the upgrade period may receive a busy signal and should re-attempt the call until the call is placed. For additional information please contact Telephone Maintenance at 801-777-9056.