Electronic device for providing communication service and method thereof

1. An electronic device comprising:

a communication circuitry;

at least one processor; and

a memory operatively coupled with the at least one processor to store a tracking area identifier (TAI) list,

wherein the memory comprises instructions which, when executed, cause the at least one processor to:

run a specified first timer upon detecting an attach failure or a tracking area update (TAU) failure in a first cell,

perform cell reselection on a second cell while the first timer runs,

determine whether a TAI of the second cell is found in the TAI list, and

when the TAI of the second cell is found in the TAI list:

forcibly expire the first timer, and

transmit an attach request message or a TAU message through the communication circuitry.

2. The electronic device of claim 1 , wherein the instructions further cause the at least one processor to:

when the TAI of the second cell is found in the TAI list, determine whether channel quality of the second cell satisfies a specified condition, and

when the channel quality of the second cell satisfies the specified condition:

expire the first timer, and

transmit the attach request message or the TAU message through the communication circuitry.

3. The electronic device of claim 2 , wherein the instructions further cause the at least one processor to:

when the channel quality of the second cell does not satisfy the specified condition, wait until the first timer expires, and

when the first timer expires, transmit the attach request message or the TAU message through the communication circuitry.

4. The electronic device of claim 1 , wherein the instructions further cause the at least one processor to, when the TAI of the second cell is found in the TAI list:

stop the first timer, and

transmit a service request message through the communication circuitry.

5. The electronic device of claim 1 , wherein the instructions further cause the at least one processor to:

bar the use of the first cell, and

control the communication circuitry to perform cell reselection on the second cell, during the first timer runs.

6. The electronic device of claim 1 , wherein the instructions further cause the at least one processor to:

transmit the attach request message in the first cell,

detect whether the attach failure occurs due to a low layer failure after the attach request message is transmitted, and

run the first timer upon detecting the attach failure due to the low layer failure.

7. The electronic device of claim 1 , wherein the instructions further cause the at least one processor to:

transmit the attach request message in the first cell,

determine whether a response for the attach request message is received during a specified time duration from a timing at which the attach request message is transmitted, and

when the response for the attach request message is not received during the specific time duration, detect the attach failure, and run the first timer.

8. The electronic device of claim 1 , wherein the instructions further cause the at least one processor to:

transmit a TAU request message in the first cell,

determine whether the TAU failure caused by the low layer failure is detected after the TAU request message is transmitted, and

run the first timer upon detecting the TAU failure.

9. The electronic device of claim 1 , wherein the instructions further cause the at least one processor to:

transmit a TAU request message in the first cell,

determine whether the response for the TAU request message is received during a specified time duration from a timing at which the TAU request message is transmitted, and

when the response for the TAU request message is not received during the specific time duration, detect the TAU failure, and run the first timer.

10. The electronic device of claim 1 , wherein the TAI list is acquired through at least one of a previously received attach accept message or a TAU accept message.

11. A method of operating an electronic device, the method comprising:

running a specified first timer upon detecting an attach failure or a tracking area update (TAU) failure in a first cell;

performing cell reselection on a second cell during the first timer runs;

determining whether a tracking area identifier (TAI) of the second cell is found in a TAI list; and

when the TAI of the second cell is found in the TAI list, forcibly expiring the first timer, and transmitting an attach request message or a TAU message through a communication circuitry.

12. The method of claim 11 , wherein the transmitting of the attach request signal or the TAU message comprises:

determining whether channel quality of the second cell satisfies a specified condition; and

when the channel quality of the second cell satisfies the specified condition, expiring the first timer, and transmitting the attach request message or the TAU message through the communication circuitry.

13. The method of claim 12 , further comprising:

when the channel quality of the second cell does not satisfy the specified condition, waiting until the first timer expires; and

when the first timer expires, transmitting the attach request message or the TAU message through the communication circuitry.

14. The method of claim 11 , further comprising:

when the TAI of the second cell is found in the TAI list, stopping the first timer; and

transmitting a service request message while omitting transmission of the attach request message or the TAU message.

15. The method of claim 11 , wherein the performing of the cell reselection comprises barring the use of the first cell, and performing cell reselection on the second cell, during the first timer runs.

16. The method of claim 11 , wherein the running of the first timer upon detecting the attach failure or the TAU failure in the first cell comprises:

transmitting the attach request message in the first cell;

detecting whether the attach failure occurs due to a low layer failure after the attach request message is transmitted; and

running the first timer upon detecting the attach failure due to the low layer failure.

17. The method of claim 11 , wherein the running of the first timer upon detecting the attach failure or the TAU failure in the first cell comprises:

transmitting the attach request message in the first cell;

determining whether a response for the attach request message is received during a specified time duration from a timing at which the attach request message is transmitted; and

when the response for the attach request message is not received during the specific time duration, detecting the attach failure, and running the first timer.

18. The method of claim 11 , wherein the running of the first timer upon detecting the attach failure or the TAU failure in the first cell comprises:

transmitting a TAU request message in the first cell;

determining whether the TAU failure caused by the low layer failure is detected after the TAU request message is transmitted; and

running the first timer upon detecting the TAU failure.

19. The method of claim 11 , wherein the running of the first timer upon detecting the attach failure or the TAU failure in the first cell comprises:

transmitting a TAU request message in the first cell;

determining whether the response for the TAU request message is received during a specified time duration from a timing at which the TAU request message is transmitted; and

when the response for the TAU request message is not received during the specific time duration, detecting the TAU failure, and running the first timer.

20. The method of claim 11 , wherein the TAI list is acquired through at least one of a previously received attach accept message or a TAU accept message.