Modelling Random time-varying delay in MATLAB

I am currently working on a project on Wireless Feedback Control which requires modelling the stochastic nature of wireless communication medium as random time-varying delay at the output of my system model which is a generalized FOPDT (First Order Plus Dead Time) model which means it has a constant delay already (proposed to be an output delay). I am able to model the FOPDT using the command tf(num,den,'Outputdelay',value) but I need to model the random time-varying delay into my model too. Any help would be appreciated. Thank you. Thank you. - Fatai