Dynamic Interference Management in Femtocells

Femtocells are tiny, low-cost, customer-deployed cellular base stations that are designed to provide supplementary coverage to existing wireless networks. However, naive femtocell deployments can cause pilot pollution and raise interference levels for users connected to macrocells, particularly when the local density of femtocells is very high, such as in an enterprise setting. We describe three dynamic femtocell pilot adjustment algorithms that balance femtocell coverage and interference: a distributed and two cooperative algorithms that leverage a lightweight, local, interference management server. Using simulations, we find that the interference management algorithms reduce outage probabilities relative to a naive interference management scheme by up to 85%. Exploiting locality through the use of dynamic interference management algorithms is a promising approach to managing femtocell deployments.