A method by which a proxy server of a wireless communication system transmits and receives packets, according to one embodiment of the present specification, comprises the steps of: receiving a data request from a terminal; receiving a packet corresponding to the data request from a data server; receiving feedback related to a transmission state from a network entity comprising a base station and/or an access point (AP); determining a redundancy rate on the basis of the feedback; encoding the received packet on the basis of the determined redundancy rate; and transmitting the encoded packet to the network entity. According to the embodiment of the present description, limited wired and wireless resources can be efficiently used, and loads to be applied to the base station or the AP can be efficiently controlled.