Wireless communication at millimeter wave (mmWave) frequencies is attractive for cellular, local area, and ad hoc networks due to the potential for channels with large bandwidths. As a byproduct of directional beamforming and propagation differences, some studies have claimed that mmWavenetworks will be noise rather than interference limited. This paper presents a derivation of the instantaneous interference-to-noise ratio (INR) distribution of a mmWave ad hoc network. Randomnetwork model of transmitters represented by a Poisson point process with a narrowband channel model is used to derive an approximation of the INR distribution.

The analysis shows that the shape of the INR distribution is determined largely by the line-of-sight interferers, which depends on the overallnetwork density and building blockage. A main conclusion drawn is that even with highly directional beamforming, interference can only sometimes be neglected in an ad hoc network. With a reasonable choice of system parameters, the interference is nearly always stronger than the noise power in densenetworks.