Communication device and method of handling a sleeping mode

1 . A communication device, comprising:

a transceiver circuit, for communicating with a network to perform a registration; and

a processing circuit, coupled to the transceiver circuit, for:

performing a sleeping mode according to a first configuration from the network;

receiving a first instruction from a user, wherein the first instruction configures the communication device to enter a high performance mode from the sleeping mode;

ignoring the first configuration and entering the high performance mode from the sleeping mode according to the first instruction;

receiving a second instruction from the user, wherein the second instruction configures the communication device to enter the sleeping mode from the high performance mode;

reconfiguring the first configuration according to the second instruction to enter the sleeping mode from the high performance mode according to the first configuration;

performing a scan continuously to connect the network, when the communication device is not in a coverage of the network and the communication device is in the high performance mode; and

performing the scan in at least one specific time interval to connect to the network, when the communication device is not in the coverage of the network and the communication device is in the sleeping mode;

wherein the transceiver circuit comprises:

a transmitting circuit, for transmitting an attach request message to the network; and

a receiving circuit, for receiving an attach accept message for responding to the attach request message from the network;

wherein the attach request message comprises a second configuration for the sleeping mode that the communication device desires, and the attach accept message comprises the first configuration for the sleeping mode.

2 . The communication device of claim 1 , wherein the first configuration is determined according to the second configuration.

3 . The communication device of claim 1 , wherein the second configuration is the same as the first configuration.

4 . The communication device of claim 1 , wherein the sleeping mode comprises at least one of a power saving mode (PSM) and an extended idle mode discontinuous reception (eDRX) mode.

5 . A method for handling a sleeping mode of a communication device, comprising:

communicating with a network to perform a registration;

transmitting an attach request message to the network;

receiving an attach accept message for responding to the attach request message from the network;

performing a sleeping mode according to a first configuration from the network;

receiving a first instruction from a user, wherein the first instruction configures the communication device to enter a high performance mode from the sleeping mode;

ignoring the first configuration and entering the high performance mode from the sleeping mode according to the first instruction;

receiving a second instruction from the user, wherein the second instruction configures the communication device to enter the sleeping mode from the high performance mode;

reconfiguring the first configuration according to the second instruction, to enter the sleeping mode from the high performance mode according to the first configuration;

performing a scan continuously to connect to the network, when the communication device is not in a coverage of the network and the communication device is in the high performance mode; and

performing the scan in at least one specific time interval to connect the network, when the communication device is not in the coverage of the network and the communication device is in the sleeping mode;

wherein the attach request message comprises a second configuration for the sleeping mode that the communication device desires, and the attach accept message comprises the first configuration for the sleeping mode.

6 . The method of claim 5 , wherein the first configuration is determined according to the second configuration.

7 . The method of claim 5 , wherein the second configuration is the same as the first configuration.

8 . The method of claim 5 , wherein the sleeping mode comprises at least one of a power saving mode (PSM) and an extended idle mode discontinuous reception (eDRX) mode.