For example, a suitably equipped laptop might be able to use both high-speed wireless LAN and cellular technology for Internet access.
Vertical handoffs between WLAN and UMTS (WCDMA) have attracted a great deal of attention in all the research areas of the 4G wireless network, due to the benefit of utilizing the higher bandwidth and lower cost of WLAN as well as better mobility support and larger coverage of UMTS.
To support vertical handover, a mobile terminal needs to have a dual mode card, for example one that can work under both WLAN and UMTS frequency bands and modulation schemes.
The handover metrics in this situation should include RSS, user preference, network conditions, application types, cost etc.
In order to allow the Corresponding Node that the MS is communicating with to find it correctly and allow the session to continue, Mobility Management is used.