2005 CENS Summer Intern:Experimentation in medium access control (MAC) protocols for wireless sensor networks cannot be accomplished completely within simulation. Live testing of MAC protocols requires analysis of active, live networks of motes. To gain a picture of the running network, researchers to this point have relied on embedding code within the motes themselves to report status and crude data loggers to collect the data. However, the side effects of embedded debug code may adversely affect an experiment, and collection of raw data is unwieldy and slow to process. Our goal is to provide a non-intrusive and user friendly system for analyzing traffic on active sensor networks which, through creative inference and post-processing, can report to the same level of as embedded debugging code without any side effects on the network. It is important that the software is also adaptive and extensible enough to allow researchers to test changes to their MAC protocol without having to modify the analysis tool or add a new protocol to the framework painlessly. The initial application of this research is to aid in the optimization of MAC protocols for high-density sensor networks.