A method for enabling group communication, the method comprising: storing, by a controller, in a database: a group identity for a communication group comprising a first set of communication devices (104, 108) and a second set of communication devices (102, 106), wherein the first set of communication devices (104, 108) are on-demand communication devices and the second set of communication devices (102, 106) are early session setup communication devices; in association with the group identity, an identity of each of the communication devices in the first set and the second set; and in association with the identity of each of the communication devices, an indication of whether a communication device is an on-demand communication device or an early session setup communication device; establishing, by the controller, a session with the second set of communication devices (102, 106), wherein the session with the second set of communication devices (102, 106) is established without a call being initiated for the communication group; detecting, by the controller, a first event associated with the initiation of a call for the communication group; in response to detecting the first event, determining, by the controller, at least one communication device that is included in the first set and is to be sent an invite to join the session based on the identity of each of the communication devices in the first set stored in the database; and sending, by the controller, an invite to the at least one communication device of the first set to join the session. storing, by a controller, in a database: a group identity for a communication group comprising a first set of communication devices (104, 108) and a second set of communication devices (102, 106), wherein the first set of communication devices (104, 108) are on-demand communication devices and the second set of communication devices (102, 106) are early session setup communication devices; in association with the group identity, an identity of each of the communication devices in the first set and the second set; and in association with the identity of each of the communication devices, an indication of whether a communication device is an on-demand communication device or an early session setup communication device; a group identity for a communication group comprising a first set of communication devices (104, 108) and a second set of communication devices (102, 106), wherein the first set of communication devices (104, 108) are on-demand communication devices and the second set of communication devices (102, 106) are early session setup communication devices; in association with the group identity, an identity of each of the communication devices in the first set and the second set; and in association with the identity of each of the communication devices, an indication of whether a communication device is an on-demand communication device or an early session setup communication device; establishing, by the controller, a session with the second set of communication devices (102, 106), wherein the session with the second set of communication devices (102, 106) is established without a call being initiated for the communication group; detecting, by the controller, a first event associated with the initiation of a call for the communication group; in response to detecting the first event, determining, by the controller, at least one communication device that is included in the first set and is to be sent an invite to join the session based on the identity of each of the communication devices in the first set stored in the database; and sending, by the controller, an invite to the at least one communication device of the first set to join the session.