In addition to the radio system and infrastructure fixed equipment, many buildings and structures are built such that the public safety radios do not work well within these buildings. As part of the system evaluation and site surveys, ACD will note which buildings have coverage problems and either Distributed Antenna Systems (DAS) will be designed as part of the new system, or a recommendation that certain classes of buildings are required to add DAS to their buildings so that first responders and other public safety personnel are always in contact with the dispatchers or other units in their agencies.