Wireless Body Area Networks (WBANs) are expected to promote new
applications for the ambulatory health monitoring of chronic patients
and elderly population, aiming to improve their quality of life and
independence. These networks are composed by wireless sensor nodes
(WSNs) used for measuring physiological variables (e.g., glucose level
in blood or body temperature) or controlling therapeutic devices (e.g.,
implanted insulin pumps). These nodes should exhibit a high degree of
energy autonomy in order to extend their battery lifetime or even make
the node supply to rely on harvesting techniques. Typically, the power
budget of WSNs is dominated by the wireless link and, hence, many
efforts have been directed during the last years toward the
implementation of power efficient transceivers.
Because of the short range (typically no more than a few meters) and low
data rate (typically in between 10 kb/s and 1 Mb/s), simple
communication protocols can be employed. One of these protocols,
specifically tailored for WBAN applications, is the Bluetooth low energy
(BLE) standard.
This book describes the challenges and solutions for the design of
ultra-low power transceivers for WBANs applications and presents the
implementation details of a BLE transceiver prototype. Coverage includes
not only the main concepts and architectures for achieving low power
consumption, but also the details of the circuit design and its
implementation in a standard CMOS technology.