OPTIMIZING VOICE CALLS ON PACKET SWITCHED NETWORKS

• US 20130044613A1
• Filed: 08/16/2011
• Published: 02/21/2013
• Est. Priority Date: 08/16/2011
• Status: Active Grant

• Current Assignee: Amazon Technologies, Inc. (Amazon.com, Inc.)
• Original Assignee: Amazon Technologies, Inc. (Amazon.com, Inc.)
• Inventors: Edara, Kiran K., Vallurupalli, Pratima
• Granted Patent: US 9,131,476 B2
• Time in Patent Office: Days
• US Class Current: 370/252
• CPC Class Codes: H04W 48/18 Selecting a network or a communication service
• CPC Class Codes: H04W 76/10 Connection setup
• CPC Class Codes: H04W 76/16 Involving different core network technologies, e.g. a packet-switched [PS] bearer in combination with a circuit-switched [CS] bearer

Abstract

Methods and systems for optimizing voice call setup times for user devices. A user device that is registered to a packet switched network and in an idle state receives a command to establish a voice call. The user device selects a legacy cell of a circuit switched network. The user device then establishes a radio connection with the selected legacy cell without first establishing a radio connection with a serving cell of the packet switched network.

Claims

1. A computer-implemented method comprising:

receiving, at a user device, a command to establish a voice call, wherein the user device is registered to a packet switched network and in an idle state;

determining a signal quality of a legacy cell of a circuit switched network;

prioritizing the legacy cell of the circuit switched network based on the signal quality;

selecting, based on the prioritizing, the legacy cell of the circuit switched network having a highest priority; and

establishing a radio connection with the selected legacy cell without first establishing a radio connection with the packet switched network.

2. The computer-implemented method of claim 1, further comprising:

before the user device enters the idle state, performing a combined attach to register the user device with the packet switched network and with the circuit switched network;

receiving an identification of a mobile switching center (MSC) of a circuit switched network to which the user device has been registered; and

storing the identification of the MSC.

3. The computer-implemented method of claim 2, wherein prioritizing the legacy cell comprises:

determining whether any legacy cell associated with the MSC is available; and

assigning a highest priority to an available legacy cell associated with the MSC.

4. The computer-implemented method of claim 1, wherein prioritizing the legacy cell comprises:

receiving network priority data associated with the circuit switched network;

storing the network priority data; and

prioritizing the legacy cell based at least in part on the network priority data.

5. The computer-implemented method of claim 1, wherein prioritizing the legacy cell comprises:

determining that a second generation wireless communication (2G) network cell and a third generation wireless communication (3G) network cell are available; and

assigning a higher priority to the 3G network cell than to the 2G network cell.

6. The computer-implemented method of claim 1, wherein:

determining the signal quality comprises measuring signal strengths of available legacy cells; and

prioritizing the legacy cell comprises assigning a highest priority to an available legacy cell having a strongest signal.

7. The computer-implemented method of claim 1, wherein the circuit switched network is one of a second generation wireless communication (2G) network or a third generation wireless communication (3G) network and the packet switched network is a long term evolution (LTE) network.

8. The computer-implemented method of claim 1, wherein the legacy cell is at least one of detected or measured before receiving the command to establish the voice call.

9. The computer-implemented method of claim 1, wherein the command is received from the packet switched network.

10. The computer-implemented method of claim 1, further comprising:

storing signal quality information of a plurality of legacy cells, wherein the signal quality of the legacy cell is determined based on the stored signal quality information.

11. The computer-implemented method of claim 1 wherein:

the determining the signal quality further comprises determining the signal quality for each of a plurality of legacy cells of a circuit switched network; and

the prioritizing further comprises prioritizing the plurality of legacy cells of the circuit switched network based on the signal quality for each of the plurality of legacy cells of the switched network.

12. A computer readable storage medium including instructions that, when executed by a processing device, cause the processing device to perform a method comprising:

receiving a command to initiate a circuit switched service by a user device that is registered to a packet switched network;

determining that the user device is in an idle state;

selecting a legacy cell of a circuit switched network by the user device based on one or more criteria; and

attempting to establish a radio connection with the selected legacy cell without first establishing a radio connection with the packet switched network.

13. The computer readable storage medium of claim 12, the method further comprising:

before the user device enters the idle state, performing a combined attach to register the user device with the packet switched network and with the circuit switched network;

receiving an identification of a mobile switching center (MSC) of a circuit switched network to which the user device has been registered; and

storing the identification of the MSC.

14. The computer readable storage medium of claim 13, wherein selecting the legacy cell comprises:

determining whether any legacy cell associated with the MSC is available; and

in response to identifying an available legacy cell associated with the MSC, selecting the identified legacy cell.

15. The computer readable storage medium of claim 12, wherein selecting the legacy cell comprises:

receiving priority data from the circuit switched network;

storing the priority data; and

selecting an available legacy cell that has a highest priority based on the received priority data.

16. The computer readable storage medium of claim 12, wherein selecting the legacy cell comprises:

determining that a second generation wireless communication (2G) network cell and a third generation wireless communication (3G) network cell are available; and

selecting the 3G network cell.

17. The computer readable storage medium of claim 12, the method further comprising:

while in the idle state, measuring signal quality of available legacy cells; and

selecting an available legacy cell having a signal quality that satisfies a minimum signal quality threshold.

18. The computer readable storage medium of claim 12, wherein the circuit switched network is one of a second generation wireless communication (2G) network or a third generation wireless communication (3G) network and the packet switched network is a long term evolution (LTE) network.

19. The computer readable storage medium of claim 12, further comprising:

selecting the legacy cell after determining that a signal quality for a serving cell of the packet switched network is below a threshold value.

20. The computer readable storage medium of claim 12, wherein the legacy cell is at least one of detected or measured before receiving the command to initiate the circuit switched service.

21. The computer readable storage medium of claim 12, wherein the command is received from the packet switched network.

22. The computer readable storage medium of claim 12, the method further comprising:

storing signal quality information of available legacy cells; and

selecting an available legacy cell having a highest signal quality based on the stored signal quality information.

23. A user device comprising:

a memory to store instructions to perform circuit switched fallback; and

a processor, coupled to the memory, configured to;

receive a command to establish a voice call, wherein the command is received after the user device has been registered to a packet switched network;

determine that the user device is in an idle state;

select a legacy cell of a second generation wireless communication (2G) network or a third generation wireless communication (3G) network; and

establish a radio connection with the selected legacy cell without first establishing a radio connection with a serving cell of the packet switched network.

24. The user device of claim 23, wherein the processor is further configured to:

before the user device enters the idle state, perform a combined attach to register the user device with the packet switched network and with the circuit switched network;

receive an identification of a mobile switching center (MSC) of a circuit switched network to which the user device has been registered; and

store the identification of the MSC.

25. The user device of claim 24, wherein selecting the legacy cell comprises:

determining whether any legacy cell associated with the MSC is available; and

in response to identifying an available legacy cell associated with the MSC, selecting the identified legacy cell.

26. The user device of claim 23, wherein selecting the legacy cell comprises:

receiving priority data from the circuit switched network;

storing the priority data; and

selecting an available cell that has a highest priority based on the received priority data.

27. The user device of claim 23, wherein selecting the legacy cell comprises:

determining that a second generation wireless communication (2G) network cell and a third generation wireless communication (3G) network cell are available; and

selecting the 3G network cell.

28. The user device of claim 23, wherein the processor is further configured to:

measure signal quality of available legacy cells; and

prioritize the available legacy cells based on at least one of an associated MSC, signal quality, network priority data or network type.

29. The user device of claim 23, wherein the processor is further configured to:

store signal quality information of available legacy cells; and

select an available legacy cell having a highest signal quality based on the stored signal quality information