An access point (102) conveys (202) to communication units (104) of a plurality of multicast groups, a first indication that the access point supports a method for sending a multicast message. The access point receives (204) a multicast message directed to a receiving one of the plurality of multicast groups, and determines (206) that the communication units belonging to the receiving one of the plurality of multicast groups also support the method. The access point signals (208) a second indication to selectively awaken the communication units belonging to the receiving one of the plurality of multicast groups, and transmits (210) the multicast message to the receiving one of the plurality of multicast groups in a manner that allows (212) at least one communication unit not belonging to the receiving one of the plurality of multicast groups to remain asleep during the transmitting.