Methods for handling a PDN disconnection request and communications apparatus utilizing the same

A method for handling a PDN disconnection request, performed by a communications device communicating with a network device, wherein the communications device is a User Equipment comprising a processor, and the method comprises:

• transmitting, by the processor of the UE, a PDN disconnect request message to the network device to request to disconnect a predetermined PDN connection;
• receiving, by the processor of the UE, a PDN disconnect reject message from the network device;
• obtaining, by the processor of the UE, a reject cause carried in the PDN disconnect reject message;
• and
• locally deactivating, by the processor of the UE, all other PDN connection(s) other than the predetermined PDN connection when the reject cause carried in the PDN disconnect reject message indicates that the last PDN disconnection is not allowed.

A communications apparatus, comprising:

• a radio transceiver, transmitting or receiving wireless radio frequency signals to communicate with a network device;
• and
• a processor, receiving a disconnection request to disconnect a predetermined PDN connection and determining whether the predetermined PDN connection is the last PDN connection,
• wherein when the predetermined PDN connection is the last PDN connection, the processor ignores the disconnection request and does not transmit a PDN disconnect request message to the network device in response to the disconnection request;
• wherein the communication apparatus further comprises:
• a network card,
• wherein the processor further removes one or more parameters associated with the predetermined PDN connection from a record maintained by the network card so as to unbind the predetermined PDN connection from the network card.

A method for handling a PDN disconnection request, performed by a communications device communicating with a network device, comprising:

• receiving a disconnection request to disconnect a predetermined PDN connection;
• determining whether the predetermined PDN connection is the last PDN connection;
• and
• ignoring the disconnection request and not transmitting a PDN disconnect request message to the network device in response to the disconnection request when the predetermined PDN connection is the last PDN connection;
• wherein the method further comprises:
• removing one or more parameters associated with the predetermined PDN connection from a record maintained by a network card of the communications device to unbind the predetermined PDN connection from the network card.

A communications apparatus, comprising:

• a radio transceiver, transmitting or receiving wireless radio frequency signals to communicate with a network device;
• and
• a processor, transmitting a PDN disconnect request message to the network device via the radio transceiver to request to disconnect a predetermined PDN connection, receiving a PDN disconnect reject message from the network device via the radio transceiver and obtaining a reject cause carried in the PDN disconnect reject message,
• wherein when the reject cause carried in the PDN disconnect reject message indicates that the last PDN disconnection is not allowed, the processor transmits one or more PDN connectivity request message(s) to the network device to recover one or more lost PDN connection(s) which is/are maintained locally by the processor other than the predetermined PDN connection;
• and
• wherein the communications apparatus is a User Equipment.

A method for handling a PDN disconnection request, performed by a communications device communicating with a network device, wherein the communications device is a User Equipment comprising a processor, and the method comprises:

• transmitting, by the processor of the UE, a PDN disconnect request message to the network device to request to disconnect a predetermined PDN connection;
• receiving, by the processor of the UE, a PDN disconnect reject message from the network device;
• obtaining, by the processor of the UE, a reject cause carried in the PDN disconnect reject message which indicates that the last PDN disconnection is not allowed;
• and
• transmitting, by the processor of the UE, one or more PDN connectivity request message(s) to the network device to recover one or more lost PDN connection(s) which is/are maintained locally by the communications device other than the predetermined PDN connection.

A communications apparatus, comprising:

• a radio transceiver, transmitting or receiving wireless radio frequency signals to communicate with a network device;
• and
• a processor, receiving a disconnection request to disconnect a predetermined PDN connection,
• wherein when the predetermined PDN connection is the last PDN connection, the processor transmits a PDN disconnect request message to the network device via the radio transceiver in response to the disconnection request to request to disconnect the predetermined PDN connection;
• wherein the communication apparatus further comprises:
• a network card,
• wherein the processor further removes one or more parameters associated with the predetermined PDN connection from a record maintained by the network card so as to unbind the predetermined PDN connection from the network card.

A method for handling a PDN disconnection request, performed by a communications device communicating with a network device, comprising:

• receiving a disconnection request to disconnect a predetermined PDN connection;
• determining whether the predetermined PDN connection is the last PDN connection;
• and
• transmitting a PDN disconnect request message to the network device in response to the disconnection request to request to disconnect the predetermined PDN connection when the predetermined PDN connection is the last PDN connection;
• wherein the method further comprises:
• removing one or more parameters associated with the predetermined PDN connection from a record maintained by a network card of the communications device to unbind the predetermined PDN connection from the network card.