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 (14a, 14b) 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.