  Recent interest in networked control systems (NCS) has instigated research in
both communication networks and control. Analysis of NCSs has usually been
performed from either the network or the control point of view, but not many
papers exist where the analysis of both is done in the same context. In this
paper an overall analysis of the networked control system is presented. First,
the procedure of obtaining the upper bound delay value for packet transmission
in the switched Ethernet network is presented. Next, the obtained delay
estimate is utilised in delay compensation for improving the Quality of
Performance (QoP) of the control systems. The presented upper bound delay
algorithm applies ideas from network calculus theory. For the improvement of
QoP, two delay compensation strategies, the Smith predictor based and the
robust control based delay compensation strategies, are presented and compared.
