Recent trends in wearable applications demand
flexible architectures being able to monitor people while they
move in free-living environments. Current solutions use either
store-download-offline processing or simple communication
schemes with real-time streaming of sensor data. This limits the
applicability of wearable applications to controlled environments
(e.g, clinics, homes, or laboratories), because they need to
maintain connectivity with the base station throughout the
monitoring process. In this paper, we present the design and
implementation of an opportunistic communication framework
that simplifies the general use of wearable devices in free-living
environments. It relies on a low-power data collection protocol
that allows the end user to opportunistically, yet seamlessly
manage the transmission of sensor data. We validate the
feasibility of the framework by demonstrating its use for
swimming, where the normal wireless communication is
constantly interfered by the environment.