Selecting base station at a multi-SIM communication device

1. A method to wirelessly connect to at least one base station at a multi-SIM communication device, wherein the multi-SIM communication device comprises a plurality of SIM card interfaces and a plurality of RF units, comprising the steps of:

scanning for base stations using a first RF unit;

observing received signal quality using the first RF unit;

transmitting data packets based in part on the received signal quality through at least one of the plurality of RF units;

selecting a first base station based in part on the received quality for the first base station;

when a second RF unit is not available, making the second RF unit available by disconnecting a wireless connection that the second RF unit has established;

establishing a wireless connection with the first base station using the second RF unit before performing the step of transmitting data packets;

wherein the received signal quality for the first base station is above a threshold; and

wherein the second RF unit is one of the at least one of the plurality of RF units.

2. According to the method of claim 1 , wherein the step of observing is performed according to the received signal quality.

3. According to the method of claim 1 , wherein each of the plurality of RF units is connected to at least one SIM card interface.

4. According to the method of claim 1 , further comprising:

establishing a wireless connection with a second base station using the second RF unit before performing the step of transmitting data packets if the first base station is unable to be connected to; and

wherein received signal quality for the second base station is above the threshold.

5. According to the method of claim 1 , further comprising:

selecting a third base station based in part on the received signal quality for the third base station;

establishing a wireless connection with the third base station using a third RF unit before performing the step of transmitting data packets;

wherein the received signal quality for the three base station is above a threshold;

wherein the third RF unit is one of the plurality of RF units; and

wherein the third RF unit is not the same as the second RF unit.

6. According to the method of claim 3 , wherein each of the plurality of RF units is connected to a plurality of SIM card interfaces through a SIM card interface selector.

7. According to the method of claim 5 , further comprising:

establishing a first tunnel through the wireless connection established with the first base station;

establishing a second tunnel through the wireless connection established with the first base station;

wherein the data packets are transmitted through the first tunnel and the second tunnel; and

wherein the first tunnel and the second tunnel are aggregated together to form an aggregated connection.

8. According to the method of claim 7 , further comprising:

when received signal quality with a base station is worsening, corresponding tunnel is not used even though the corresponding tunnel is not broken;

wherein the base station is one of the first station and the second station;

wherein the corresponding tunnel is the tunnel established between a RF unit with the base station; and

wherein the RF unit is one of the first RF unit and the second RF unit.

9. A multi-SIM communication device capable of wirelessly connecting at least one base station, the multi-SIM device comprising:

a plurality of SIM card interfaces;

a plurality of RF units;

at least one network interface;

at least one processing unit;

at least one memory;

at least one storage unit storing program instructions executable by the at least one processing unit for:

scanning for base stations using a first RF unit;

observing received signal quality using the first RF unit;

transmitting data packets based in part on the received signal quality through at least one of the plurality of RF units;

selecting a first base station based in part on the received signal quality for the first base station;

when a second RF unit available, making the second RF unit available by disconnecting a wireless connection that the second RF unit has established;

establishing a wireless connection with the first base station using the second RF unit before performing the step of transmitting data packets;

wherein the received signal quality for the first base station is above a threshold; and

wherein the second RF unit is one of the at least one of the plurality of RF units.

10. The multi-SIM communication device of claim 9 , wherein the step of observing is performed according to the received signal quality.

11. The multi-SIM communication device of claim 9 , wherein each of the plurality of RF units is connected to at least one SIM card interface.

12. The multi-SIM communication device of claim 9 , wherein each of the plurality of RF units is connected to a plurality of SIM card interfaces through a SIM card interface selector.

13. The multi-SIM communication device of claim 9 , wherein the at least one storage unit further storing program instructions executable by the at least one processing unit for:

establishing a wireless connection with a second base station using the second RF unit before performing the step of transmitting data packets if the first base station is unable to be connected to; and

wherein received signal quality for the second base station is above the threshold.

14. The multi-SIM communication device of claim 9 , wherein the at least one storage unit further storing program instructions executable by the at least one processing unit for:

selecting a third base station based in part on the received signal quality for the third base station;

establishing, a wireless connection with the third base station using a third RF unit before performing the step of transmitting data packets;

wherein the received signal quality for the three base station is above a threshold;

wherein the third RF unit is one of the plurality of RF units;

wherein the third RF unit can be the same or different from the first RF unit; and

wherein the third RF unit is not the same as the second RF unit.

15. The multi-SIM communication device of claim 14 , wherein the at least one storage unit further storing program instructions executable by the at least one processing unit for:

establishing a first tunnel through the wireless connection established with the first base station;

establishing a second tunnel through the wireless connection established with the first base station;

wherein the data packets are transmitted through the first tunnel and the second tunnel; and

wherein the first tunnel and the second tunnel are aggregated together to form an aggregated connection.

16. The multi-SIM communication device of claim 15 , further comprising:

when received signal quality with a base station is worsening, corresponding tunnel is not used even though the corresponding tunnel is not broken;

wherein the base station is one of the first station and the second station;

wherein the corresponding tunnel is the tunnel established between a RF unit with the base station; and

wherein the RF unit is one of the first RF unit and the second RF unit.