Power control for two-tier femtocell networks using pricing mechanism via emergency message

This paper proposes the power control method using a pricing mechanism via emergency message to mitigate the cross-channel interference for downlink transmission in two-tier femtocell networks, where macrocell and overlaid femtocells share the same frequency band (i.e., cochannel deployment). Macrocell users measure the channel gain from base station to user, and computes the achieved SINR. If the macrocell achieved SINR is not satisfied for a target SINR, a macrocell user broadcasts emergency message to close-by femtocell users. When femtocell users receive the emergency message, the femtocell pricing coefficient value is forced to increase, which in turn decreases their power, resulting in reduced cross-channel interference at the macrocell. Consequently, the macrocell user will then satisfy the target SINR faster, but with some modest loss in total throughput.