Communication system for reducing congestion

A communication system, which comprises a base station device connected to a core network and a plurality of terminal device groups including communication terminal devices connected to said base station device so as to perform radio communication therewith, wherein

• said base station device transmits, to a communication terminal device to be called, a paging message including a calling indicator indicating that said communication terminal device is being called,
• said communication terminal device starts, upon reception of the paging message including the calling indicator indicating that said communication terminal device is being called, communication with said base station device,
• said terminal device groups includes a group of machine type communication (MTC) devices and a group of non-MTC devices,
• the paging message includes a paging record list including equipment identifiers for a plurality of non-MTC devices, and
• the calling indicator indicates that an MTC device is being called.

A communication system, which comprises a base station device connected to a core network and a plurality of terminal device groups including communication terminal devices connected to said base station device so as to perform radio communication therewith, wherein

• said base station device transmits, to a communication terminal device to be called, a paging message notifying calling,
• said communication terminal device starts, upon reception of said paging message addressed to the own device from said base station device, communication with said base station device, and
• when said paging message is transmitted to the plurality of communication terminal devices included in the different terminal device groups, said paging message is transmitted to each of said terminal device groups over a different radio frame,
• said terminal device groups includes a group of machine type communication (MTC) devices and a group of non-MTC devices, and
• said paging message is transmitted to the MTC devices over a sub-frame, within a radio frame, different from a sub-frame, within the radio frame, that said paging message is transmitted to the non-MTC devices.

A communication system, which comprises a base station device connected to a core network and a plurality of terminal device groups including communication terminal devices connected to said base station device so as to perform radio communication therewith, wherein

• if a predetermined disconnection condition is satisfied after a predetermined equipment-side-process is performed between a communication terminal device and said base station device, said base station device chooses to disconnect the communication with said communication terminal device,
• if a prediction condition of predicting that said base station device has chosen to disconnect the communication with said communication terminal device is satisfied, said communication terminal device performs a process for establishing communication with said base station device without knowing whether or not said process for establishing communication with said base station device is needed,
• the prediction condition includes a threshold for judging whether or not the process for establishing communication is to be performed or an indicator indicating whether or not the process for establishing communication is to be performed, and
• the prediction condition is notified to the communication terminal device by the base station device in advance of the base station device choosing to disconnect the communication with said communication terminal device.