Device and method for managing multicast group in wireless network

A joining device attempting to join a first multicast group in which data is directly sent between member devices or data is sent using hopping between the member devices, the joining device comprising:

• a transmission unit configured to send a join request for joining the first multicast group to a member device included in a second multicast group;
• and
• a reception unit configured to receive a response to the join request from the member device if the first multicast group is identical with the second multicast group;
• wherein whether the first multicast group is identical with the second multicast group is determined by comparing information about the first multicast group, extracted from the join request, with information about the second multicast group;
• and
• wherein the join request is sent to another device if the first multicast group is not identical with the second multicast group.

A member device included in a multicast group, the member device comprising:

• a determination unit configured to determine that the multicast group has been damaged if information about the multicast group has not been received from a withdrawing device included in the multicast group for a specific time;
• a transmission unit configured to send restoration information about the multicast group to a second member device included in the multicast group based on a result of the determination;
• and
• a reception unit configured to:
• receive a response to the restoration information from the second member device;
• and
• restore the multicast group using the response.