An electronic device for providing a packet-based voice call function is provided. The electronic device includes a transmit antenna; a receive antenna; and a communication circuit configured to establish an uplink channel using the transmit antenna, establish a downlink channel using the receive antenna, perform a packet-based voice call using the uplink channel and the downlink channel, obtain information associated with the downlink channel, determine a download schedule based on the obtained information associated with the downlink channel, determine a time required from a transmission request to a base station to a grant time, and transmit a voice packet over the uplink channel based on the download schedule and the time required from the transmission request to the base station to a grant time.