Signal Outages of CSMA/CA-Based Wireless Networks with Different AP Densities

In wireless networks, users may experience outages owing to low received signal strength. Divergent from other research, we investigate the outages for users of CSMA/CA-based wireless networks when multiple access points (APs) and multiple users are randomly positioned in a given area. We model the locations of the APs and users using independent homogeneous Poisson point processes (PPPs), and analyze the signal outage probabilities of users when there are different numbers of access points, as well as when different modulation and coding schemes (MCSs) are used for communication. We also investigate heterogeneous CSMA/CA-based wireless networks, wherein the APs use different transmit powers. Then, we evaluate the results and compare the signal outage rates of users with the signal-to-interference-plus-noise ratio (SINR) outage rates of users in both homogeneous and heterogeneous IEEE 802.11a wireless networks using extensive event-driven simulations. The simulation results validate our analysis on the signal outages of users in multi-cell, multi-user wireless networking environments, and show that a significant portion of outages are caused by the signal outages when AP densities are low and high MCS levels are used for communication