Communication system switching method, and terminal device using this method

摘要

A W-LAN communication unit, a personal handyphone communication unit and an EV-DO communication unit include communication functions corresponding to their communication systems. A W-LAN quality measurement unit detects a value corresponding to RSSI, which is the reception power. An EV-DO quality measurement unit periodically obtains EV-DO quality values. A throughput measurement unit measures the throughput values for the individual communication systems. A condition setting unit designates a condition for the selection of the W-LAN communication unit, the personal handyphone communication unit or the EV-DO communication unit. A threshold value storage unit stores threshold values. A first determination unit compares the throughput values for the W-LAN and the RSSI with threshold values. A second determination unit compares the EV-DO quality values with threshold values. And a selector performs the switching of communication systems.