Techniques for accessing a wireless communication system with tune-away capability

• US 8,238,321 B2
• Filed: 11/05/2010
• Issued: 08/07/2012
• Est. Priority Date: 02/03/2005
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Joshi, Abhay Arvind, Rezaiifar, Ramin, Turner, Simon
• Primary Examiner(s): Gonzalez, Amancio
• Application Number:
  US12/940,886
• Publication Number:
  US 20110044300A1
• Time in Patent Office: 641 Days
• Field of Search: 370/345, 370/328, 455/522, 455/434, 4555521-5531
• US Class Current: 370/345
• CPC Class Codes: H04B 1/707 using direct sequence modulation
• CPC Class Codes: H04W 74/00 Wireless channel access
• CPC Class Codes: H04W 88/06 adapted for operation in multiple networks or having at least two operational modes, e.g. multi-mode terminals

Abstract

To access a first communication system, a terminal determines a transmission time for an access probe, an expected response time from the system, and a protected time interval based on the transmission time and/or expected response time. The terminal determines a starting time for sending the access probe such that the protected time interval does not overlap a tune-away interval in which the terminal is to monitor anther frequency/air-interface. This starting time may be set initially to the end of a prior access probe plus a pseudo-random wait duration and may be advanced forward or moved backward in time, if needed, by a time duration selected such that the protected time interval does not overlap the tune-away interval.

Claims

1. A processor comprising:

a first module for causing a computer to determine a protected time interval required after an access request is sent to a first communication system, wherein the first communication system is entitled to respond anytime within the protected time interval;

a second module, comprising hardware, for causing the computer to determine a starting time for sending the access request such that the protected time interval does not overlap a tune-away interval; and

a third module for causing the computer to initiate sending the access request to the first communication system at the starting time.

2. The processor of claim 1, further comprising a module for causing the computer to tune a receiver to the first communication system during the protected time interval and to tune away from the first communication system during the tune-away interval.

3. The processor of claim 2, further comprising a module for causing the computer to direct the receiver to tune to a second communication system prior to the tune-away interval and to direct the receiver to tune back to the first communication system after the tune-away interval.

4. The processor of claim 3, further comprising a module for causing the computer to receive a paging channel from the second communication system during the tune-away interval.

5. The processor of claim 1, further comprising a module for causing the computer to determine an expected response time for an acknowledgment from first communication system for the access request, and determine the protected time interval based on the expected response time.

6. The processor of claim 1, further comprising a module for causing the computer to determine a transmission time for the access request, wherein the first module determines the protected time interval further based on the transmission time.

7. The processor of claim 1, further comprising a module for causing the computer to determine an initial time for sending the access request, and wherein the second module determines the starting time as the initial time plus or minus a zero or non-zero time duration selected such that transmission of the access request at the starting time results in the protected time interval not overlapping the tune-away interval.

8. The processor of claim 7, further comprising a module for causing the computer to determine a pseudo-random wait duration and to set the initial time to the end of a prior access request plus the pseudo-random wait duration.

9. The processor of claim 1, further comprising a module for causing the computer to initialize the starting time to the end of a prior access request, to determine a pseudo-random wait duration, to advance the starting time by the pseudo-random wait duration, and to repeat determining a pseudo-random wait duration and advancing the starting time until transmission of the access request at the starting time results in the protected time interval not overlapping the tune-away interval.

10. The processor of claim 1, wherein the tune-away interval corresponds to an assigned paging slot for a second communication system.

11. The processor of claim 1, wherein the tune-away interval corresponds to a pilot transmission or a signaling transmission from a second communication system.

12. The processor of claim 1, wherein the tune-away interval corresponds to a measurement interval for a second communication system.

13. A processor comprising:

a first module, comprising hardware, for determining a protected time interval required after an access request is sent to a data only communication system, wherein the data only communication system is entitled to respond within the protected time interval, wherein the protected time interval is a time interval in which a receiver is tuned to the data only communication system;

a second module for determining a starting access channel cycle for sending the access request such that the protected time interval does not overlap a tune-away interval, wherein the tune-away interval is a time interval in which the receiver is tuned to a data and voice communication system; and

a third module for sending the access request to the data only communication system at the starting access channel cycle.

14. The processor of claim 13, wherein the first module determines the protected time interval at least in part by determining a transmission time for the access request, determining an expected response time for an acknowledgement from the data only communication system for the access request, and setting the protected time interval based on the transmission time and the expected response time.

15. The processor of claim 13, wherein the second module determines the starting access channel cycle at least in part by determining a pseudo-random wait duration, setting the starting access channel cycle to a first access channel cycle located after an end of a prior access request plus the pseudo-random wait duration, and selecting a second access channel cycle as the starting access channel cycle where transmission of the access request at the first access channel cycle results in the protected time interval overlapping the tune-away time interval.

16. The processor of claim 15, wherein the second access channel cycle occurs after the first access channel cycle.

17. The processor of claim 13, further comprising:

a fourth module for tuning the receiver to the data and voice communication system prior to the tune-away interval;

a fifth module for receiving a paging channel from the data and voice communication system; and

a sixth module for tuning the receiver back to the data only communication system after the tune-away interval.

18. A memory unit including machine-executable instructions to cause a processor in a wireless device to:

determine a protected time interval required after an access request is sent to a data only communication system, wherein the data only communication system is entitled to respond within the protected time interval, wherein the protected time interval is a time interval in which a receiver is tuned to the data only communication system;

determine a starting access channel cycle for sending the access request such that the protected time interval does not overlap a tune-away interval, wherein the tune-away interval is a time interval in which the receiver is tuned to a data and voice communication system; and

send the access request to the data only communication system at the starting access channel cycle.

19. The memory unit of claim 18, wherein the instructions cause the processor in the wireless device to determine the protected time interval at least in part by determining a transmission time for the access request, determining an expected response time for an acknowledgement from the data only communication system for the access request, and setting the protected time interval based on the transmission time and the expected response time.

20. The memory unit of claim 18, wherein the instructions cause the processor in the wireless device to determine the starting access channel cycle at least in part by determining a pseudo-random wait duration, set the starting access channel cycle to a first access channel cycle located after an end of a prior access request plus the pseudo-random wait duration, and select a second access channel cycle as the starting access channel cycle where transmission of the access request at the first access channel cycle results in the protected time interval overlapping the tune-away time interval.

21. The memory unit of claim 18, wherein the instructions cause the processor in the wireless device to tune the receiver to the data and voice communication system prior to the tune-away interval, receive a paging channel from the data and voice communication system, and tune the receiver back to the data only communication system after the tune-away interval.

22. An apparatus, comprising:

means for determining a protected time interval required after an access request is sent to a data only communication system, wherein the data only communication system is entitled to respond within the protected time interval, wherein the protected time interval is a time interval in which a receiver is tuned to the data only communication system;

means for determining a starting access channel cycle for sending the access request such that the protected time interval does not overlap a tune-away interval, wherein the tune-away interval is a time interval in which the receiver is tuned to a data and voice communication system; and

means for sending the access request to the data only communication system at the starting access channel cycle.

23. The apparatus of claim 22, wherein the means for determining the protected time interval comprises:

means for determining the protected time interval at least in part by determining a transmission time for the access request;

means for determining an expected response time for an acknowledgement from the data only communication system for the access request; and

means for setting the protected time interval based on the transmission time and the expected response time.

24. The apparatus of claim 22, wherein the means for determining the starting access channel cycle comprises:

means for determining the starting access channel cycle at least in part by determining a pseudo-random wait duration;

means for setting the starting access channel cycle to a first access channel cycle located after an end of a prior access request plus the pseudo-random wait duration; and

means for selecting a second access channel cycle as the starting access channel cycle where transmission of the access request at the first access channel cycle results in the protected time interval overlapping the tune-away time interval.

25. The apparatus of claim 22, further comprising:

means for tuning the receiver to the data and voice communication system prior to the tune-away interval;

means for receiving a paging channel from the data and voice communication system; and

means for tuning the receiver back to the data only communication system after the tune-away interval.