Before revision:  This poses a significant challenge, as multi-hop analysis for heterogeneous wireless networks does not exist prior to our work. We overcome this challenge by extending a newly developed methodology based on (min,x) network calculus and provide a closed-form expression for the end-to-end delay violation probability over a cascade of heterogeneous buffered wireless fading channels.
After revision:  This poses a significant challenge, as multi-hop analysis for heterogeneous wireless networks using our previously developed stochastic network calculus approach for performance analysis of a cascade of heterogeneous buffered wireless fading channels.