Multicasting method with changing transmission method dependent on receiving state at the base station

摘要

In a multicast transmission system in which the same information is transmitted from a base station to a plurality of mobile stations, the mobile station sends a retransmission request signal to the base station when detecting an error in a received multicast signal. The base station monitors a receiving state of a multicast signal in the mobile stations, and changes in transmission method to conform to the receiving state according to a result of monitoring, and sends a multicast signal.