A communication method of a server that transmits a packet by multicast or broadcast via a wireless base station to at least one or more wireless terminals connected to the wireless base station via a wireless network using a channel, the method comprising: acquiring information relating to the wireless terminal ; deciding priority of data based on information relating to the wireless terminal ; generating the packet including the data regarding which the priority has been decided; acquiring channel-used time that is time over which the channel is used per unit of time at the wireless base station ; calculating channel-usable time T usable that is time over which the channel can be used per unit of time T, for the wireless base station to transmit the packet to the wireless termina , based on the channel-used time T used , wherein T usable = α x (T - T used ), for 0 < α ≤ 1; calculating a first channel usage estimated time that is time estimated to be used for the wireless base station to use the channel to transmit the packet to the wireless terminal ; calculating a wireless transmission rate to be applied when the wireless base station transmits the packet to the wireless terminal , based on the priority of the data included in the packet, to where the first channel usage estimated time is within the channel-usable time; and transmitting the packet, and information indicating the wireless transmission rate, to the wireless base station , wherein in the acquiring of information relating to the wireless terminal , a feedback packet including information relating to the wireless terminal is received from the wireless terminal , and wherein a time interval for the wireless terminal to transmit the feedback packet to the server is decided based on the number of the wireless terminals connected to the wireless network , and wherein the time interval for the wireless terminal to transmit the feedback packet to the server is also decided based on the channel-used time. acquiring information relating to the wireless terminal ; deciding priority of data based on information relating to the wireless terminal ; generating the packet including the data regarding which the priority has been decided; acquiring channel-used time that is time over which the channel is used per unit of time at the wireless base station ; calculating channel-usable time T usable that is time over which the channel can be used per unit of time T, for the wireless base station to transmit the packet to the wireless termina , based on the channel-used time T used , wherein T usable = α x (T - T used ), for 0 < α ≤ 1; calculating a first channel usage estimated time that is time estimated to be used for the wireless base station to use the channel to transmit the packet to the wireless terminal ; calculating a wireless transmission rate to be applied when the wireless base station transmits the packet to the wireless terminal , based on the priority of the data included in the packet, to where the first channel usage estimated time is within the channel-usable time; and transmitting the packet, and information indicating the wireless transmission rate, to the wireless base station , wherein in the acquiring of information relating to the wireless terminal , a feedback packet including information relating to the wireless terminal is received from the wireless terminal , and wherein a time interval for the wireless terminal to transmit the feedback packet to the server is decided based on the number of the wireless terminals connected to the wireless network , and wherein the time interval for the wireless terminal to transmit the feedback packet to the server is also decided based on the channel-used time. <EOS>