RETRANSMISSION METHOD, BASE STATION, AND USER DEVICE IN MULTICAST SYSTEM

摘要

Disclosed are a retransmission method, a base station, and a user device in a multicast system. In order to reduce uplink signaling resource, a new MNI (Multiple NACK Indicator) message is added to an uplink common feedback channel in an existing E-MBMS system. The MNI message enables decision of an XOR retransmission group which satisfies the XOR retransmission condition. As compared to a conventional XOR retransmission, the number of uplink signalings does not depend on the number of receivers. That is, when a plenty of receptions are present, it is possible to significantly reduce uplink signalings.