  A wireless sensor/actuator network (WSAN) is a group of sensors and actuators
that are geographically distributed and interconnected by wireless networks.
Sensors gather information about the state of physical world. Actuators react
to this information by performing appropriate actions. WSANs thus enable cyber
systems to monitor and manipulate the behavior of the physical world. WSANs are
growing at a tremendous pace, just like the exploding evolution of Internet.
Supporting quality of service (QoS) will be of critical importance for
pervasive WSANs that serve as the network infrastructure of diverse
applications. To spark new research and development interests in this field,
this paper examines and discusses the requirements, critical challenges, and
open research issues on QoS management in WSANs. A brief overview of recent
progress is given.
