  This paper presents the positive real analysis and synthesis for Networked
Control Systems (NCS) in discrete time. Based on the definition of passivity,
the sufficient condition of NCS is given by stochastic Lyapunov functional. The
controller via state feedback is designed to guarantee the stability of NCS and
closed-loop positive realness. It is shown that a mode-dependent positive real
controller exists if a set of coupled linear matrix inequalities has solutions.
The controller can be then constructed in terms of the solutions.
