Advanced Wireless Networks, 3rd Edition

21mmWave Networks

As already indicated in Chapter 1, millimeter wave (mmWave) technology might be integrated for short transmissions in 5G cellular networks between adjacent subcells. Because mmWave signals are sensitive to blockage, prior models for cellular networks operated in the ultra high frequency (UHF) band do not apply to analyze mmWave subcellular networks directly. Using the concepts from stochastic geometry, this section discusses a general framework to evaluate the coverage and rate performance in mmWave subcellular networks. Using a distance dependent line of site (LOS) probability function, the locations of the LOS and nonLOS base stations are modeled as two independent nonhomogeneous Poisson point processes (PPPs), to which different path loss laws are applied. Based on the such framework, expressions for the signal to noise and interference ratio (SINR) and rate coverage probability are derived. The mmWave coverage and rate performance are examined as a function of the antenna geometry and base station density. The case of dense networks is further analyzed by applying a simplified system model, in which the LOS region of a user is approximated as a fixed LOS ball [1]. The results show that dense mmWave networks can achieve comparable coverage and much higher data rates than conventional UHF cellular systems, despite the presence of blockages. The results suggest that the cell size to achieve the optimal SINR scales with the average size of the area that is ...