Patent ID: 8139501
Filing Date: 2012-03-20
Classification: H04L

Abstract:
1. A relay device comprising: a memory which stores information sets each including multicast group information indicative of a multicast group in which a mobile terminal participates and zone information indicative of a zone to which a plurality of base stations, including a base station performing wireless communications with the mobile terminal, belong; and a processor which executes processes comprising: first generating at least one query packet, for checking whether there is any mobile terminal that continues to participate in a checking target multicast group, in which information indicative of the checking target multicast group is set; specifying, from the information sets stored in the memory, an information set including multicast group information indicative of the checking target multicast group; second generating user data packets each containing a generated query packet from the first generating and same timing information specifying timing at which the query packet is to be transmitted from a base station; and transmitting the user data packets to base stations belonging to a zone identified by zone information included in the specified information set, respectively.