| 摘要 |
<p>The present invention relates to a relay device realizing multicast communications efficient and effective in mobile communications. The relay device transmitting a multicast user data packet containing a content to a plurality of base stations comprises a storage means storing, in a storage unit, information about a multicast group, information about the base station and information about the zone in a way that associates these items of information with each other, a determining means determining, when receiving a LEAVE packet via the base station, whether or not it is required to transmit a query packet about a leave target multicast group by comparing the base station stored in the way being associated with the leave target multicast group and with the zone to which the via-base-station belongs with the base station relaying the received LEAVE packet, and a transmitting means transmitting the user data packet containing the query packet to each of the base stations belonging to the zone on the basis of a result of the determination by the determining means.</p> |
