The advances of various wireless technologies has motivated research efforts towards the next generation of wireless communication systems to satisfy the even growing wireless services with a higher quality of service (QoS). Different wireless networks, such as Wireless WANs (e.g., 2.5G and 3G or Beyond), Wireless MANs (e.g., IEEE 802.16),WLANs (e.g., IEEE 802.11a/b/e/g), and Wireless PANs (e.g., Bluetooth), deploy different radio spectrums with different spaces and may be co-located in the same locations to provide even more exciting and efficient services. We advocate the integration of multiple radios in a single mobile device for enjoying the services from the desirable networks. We call this terminal as multi-mode terminal. The multi-mode terminal may integrate with cellular/WLAN, cellular/Bluetooth, Cellular/Satellite, WLAN/WPAN or their combinations. With a multi-mode terminal, multiple communication capabilities must be opportunistically exploited to ensure the user will use “always the best connectivity” opportunity available at any given time and location for each service (or application).