Abstract—Wireless body area networks (WBANs) and their supporting information infrastructures offer unprecedented opportunities to monitor state of health without constraining wearer activities. To increase acceptance of personal monitoring technology while lowering equipment cost, advances must be made in interoperability (at both the system and device levels) and security. This paper addresses the functional needs of future point-of-care environments that will employ ad-hoc WBANs for patient monitoring and treatment. It then summarizes the use cases and constraints that will help to formulate rules of engagement for smart, interoperable components that operate within a distributed medical monitoring environment populated by WBANs and other local sensors.