Distributed Antenna Systems (DAS) are being installed in large numbers to support in-building wireless services with demands ranging from capacity enhancements for large stadiums to coverage enhancements inside office buildings, tunnels, and subterranean areas not served by outdoor networks. Testing these systems can be almost as challenging as designing and installing the system as each system is unique and there is no “one size fits all” testing solution. The various types of components used in each system will determine ways to test each DAS. This application note provides an overview of several component types, and how to break down a DAS for effective testing and troubleshooting.