A method (400) for coordinating access to a wireless medium among multiple co-located body area networks (BANs). The method comprises detecting, by a master device of a first BAN, at least one alien BAN using beacons received from at least one co-located BAN, wherein an alien BAN is a BAN having its round start time (RST) misaligned with a RST of the first BAN (S410); recording a RST offset between the first BAN and the at least one alien BAN (S420); based on the RST offset determining which of the first BAN and the at least one alien BAN is an initiator BAN and which is a target BAN (S430); and realigning the RST of the initiator BAN with the RST of the target BAN (S460).