Disclosed is a radio terminal including: a message transmitter-receiver configured to transmit and receive an IEEE 802.21 message using a protocol of a layer lower than an IP layer to and from a target radio base station for handover before an IP address acquisition unit acquires a new IP address; and a quality measurement unit configured to measure a radio communication quality including at least one of transmission delay and jitter in a radio communication path between the radio terminal and the target radio base station by using the IEEE 802.21 message transmitted and received by the message transmitter-receiver.