This paper investigates the problem of stabilization for linear system considering communication and network
characteristics together. Firstly, the minimal signal-to-noise ratios(SNRs) required for stabilisability are obtained in
continuous-time networked control system(NCS) with varying delay by using linear matrix inequality(LMI) approach. Then
the similar results are extended to a kind of discrete-time heterogeneous networked control system. The proposed multisensors
stochastic delays model which is more practical can depict the characteristic of token-passing bus control network.
Finally, the above theories are tested by numerical examples, and relations among unstable poles, delays and SNRs are
illustrated explicitly.