System and method for controlling network, network controlling apparatus, and mobile terminal used in network control system

A network control apparatus provided on a network to control connection of a mobile terminal that moves across multiple types of wireless systems, comprising:

• signal transmitting/receiving means that transmits and receives a control signal defined by each of the wireless systems;
• protocol converting means that converts the control signal to a common protocol independent of each of the wireless systems;
• entity communication controlling means that communicates with a plurality of functional entities provided on the network to implement network control using the common protocol;
• location registration ID managing means that manages a common location registration ID allocated in common to service areas defined by wireless access points of the multiple types of wireless systems;
• broadcasting means that causes the wireless access points to broadcast the common location registration ID;
• and
• location registration means that carries out location registration using the common location registration ID upon receiving a location registration request from the mobile terminal currently located in one of the service areas.

A network control method for controlling connection between a mobile terminal and multiple types of wireless systems accommodated in a network, each of the wireless systems having a wireless access point, the method comprising the steps of:

• receiving at a prescribed node on the network a control signal defined by each of the wireless systems;
• converting at the prescribed node the control signal to a common protocol having a common format independent of the wireless systems;
• carrying out communications between the prescribed node and functional entities provided on the network using the common protocol to implement network control;
• managing a common location registration ID allocated in common to service areas defined by wireless access points of the multiple types of wireless systems;
• broadcasting, using the wireless access points, the common location registration ID;
• and
• carrying out location registration using the common location registration ID upon receiving a location registration request from the mobile terminal currently located in one of the service areas.