This thesis focuses on the study of mobile wireless sensor networks applied to healthcare
scenarios. The promotion of better quality-of-life for hospitalized patients is addressed in this
research work with a solution that can help these patients to keep their mobility (if possible).
The solution proposed allows remote monitoring and control of patients’ health in real-time
and without interruptions. Small sensor nodes able to collect and send wirelessly the health
parameters allow for the control of the patients' health condition. A network infrastructure,
composed by several access points, allows the connection of the sensor nodes (carried by the
patients) to remote healthcare providers. To ensure continuous access to sensor nodes special
attention should be dedicated to manage the transition of these sensor nodes between
different access points’ coverage areas. The process of changing an access point attachment
of a sensor node is called handover. In that context, this thesis proposes a new handover
mechanism that can ensure continuous connection to mobile sensor nodes in a healthcare
wireless sensor network. Due to the limitations of sensor nodes’ resources, namely available
energy (these sensor nodes are typically powered by small batteries), the proposed
mechanism pays a special attention in the optimization of energy consumption. To achieve
this optimization, part of this work is dedicated to the construction of a small sensor node.
The handover mechanism proposed in this work is called Hand4MAC (handover mechanism for
MAC layer). This mechanism is compared with other mechanisms commonly used in handover
management. The Hand4MAC mechanism is deployed and validated through by simulation and
in a real testbed. The scenarios used for the validation reproduces a hospital ward. The
performance evaluation is focused in the percentage of time that senor nodes are accessible
to the network while traveling across several access points’ coverage areas and the energy
expenditures in handover processes. The experiments performed take into account various
parameters that are the following: number of sent messages, number of received messages,
multicast message usage, energy consumption, number of sensor nodes present in the
scenario, velocity of sensor nodes, and time-to-live value. In both simulation and real
testbed, the Hand4MAC mechanism is shown to perform better than all the other handover
mechanisms tested. In this comparison it was only considered the most promising handover
mechanisms proposed in the literature.Fundação para a Ciência e a Tecnologia (FCT
