Mixed Spatial Traffic Modeling of Heterogeneous Cellular Networks

An accurate traffic model is a key factor in the research and design of 5G heterogeneous networks. The literature on mixture of non-uniform and uniform traffic models is very limited. The mixed traffic model includes the non-uniform UEs and uniform UEs at the same time, which represents a more realistic traffic distribution. In this paper, we give a mixed traffic model that is based on the available K-tier heterogeneous network, in which each tier has its own transmit power, density, signal to interference ratio (SIR) coverage threshold and path loss exponent. This model also contains an adjustable parameter p which represents the correlation between BS and UE on non- uniform situation and an adjustable parameter r which represents the density ratio of non-uniform UEs to uniform UEs. This traffic model is more realistic because some UEs are spread uniformly and some UEs are clustered around the cell center non-uniformly, especially for the small cells. The expression of the performance metric of coverage probability is derived. The results obtained by analytical expressions and simulations align closely.