DEVICES AND METHODS FOR FACILITATING ACCESS PROBE SEQUENCES

• US 20130130738A1
• Filed: 10/09/2012
• Published: 05/23/2013
• Est. Priority Date: 11/18/2011
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Cherian, George, Wang, Jun
• Granted Patent: US 9,241,298 B2
• Time in Patent Office: Days
• US Class Current: 455/522
• CPC Class Codes: H04W 36/0083 Determination of parameters used for hand-off, e.g. generation or modification of neighbour cell lists
• CPC Class Codes: H04W 36/08 Reselecting an access point
• CPC Class Codes: H04W 36/32 by location or mobility data, e.g. speed data
• CPC Class Codes: H04W 48/16 Discovering, processing access restriction or access information
• CPC Class Codes: H04W 48/20 Selecting an access point
• CPC Class Codes: H04W 52/10 Open loop power control
• CPC Class Codes: H04W 52/225 Calculation of statistics, e.g. average, variance
• CPC Class Codes: H04W 52/228 using past power values or information
• CPC Class Codes: H04W 52/285 taking into account the mobility of the user
• CPC Class Codes: H04W 52/50 at the moment of starting communication in a multiple access environment

Abstract

Access terminals are adapted to transmit a plurality of previously successful access probes to a network node, and determine an initial transmission power level for subsequent access attempts. The initial transmission power level can be determined based at least in part on one or more parameters associated with the plurality of previously successful access probes. An initial access probe of a subsequent access attempt can then be transmitted at the determined initial transmission power level. Network nodes that receive the one or more access probes from access terminals can send a message instructing the access terminals to employ a particular initial transmission power level for a subsequent access attempt. Other aspects, embodiments, and features are also included.

Claims

1. An access terminal, comprising:

a communications interface;

a storage medium; and

a processing circuit coupled to the communications interface and the storage medium, the processing circuit adapted to;

transmit via the communications interface a plurality of previously successful access probes;

determine an initial transmission power level based at least in part on one or more parameters associated with the plurality of previously successful access probes; and

transmit via the communications interface an initial access probe of a subsequent access attempt, wherein the initial access probe is transmitted at the determined initial transmission power level.

2. The access terminal of claim 1, wherein the processing circuit is adapted to:

determine the initial transmission power level based at least in part on an average power level of at least some of the plurality of previously successful access probes.

3. The access terminal of claim 1, wherein the processing circuit is adapted to:

determine the initial transmission power level based at least in part on a difference of an average open-loop power level associated with the plurality of previously successful access probes and an open-loop power level associated with the subsequent access attempt.

4. The access terminal of claim 1, wherein the processing circuit is adapted to:

determine the initial transmission power level based at least in part on;

an average power level of at least some of the plurality of previously successful access probes, and a difference of an average open-loop

5. The access terminal of claim 1, wherein the processing circuit is further adapted to:

determine whether the access terminal is mobile or at least substantially stationary;

transmit the initial access probe of a subsequent access attempt at the determined initial transmission power level when the access terminal is determined to be at least substantially stationary; and

transmit the initial access probe of a subsequent access attempt at a default initial transmission power level when the access terminal is determined to be mobile.

6. The access terminal of claim 1, wherein the processing circuit is further adapted to:

receive via the communications interface a message instructing the access terminal to employ a particular initial transmission power level for a subsequent access attempt.

7. The access terminal of claim 1, wherein the processing circuit is further adapted to:

monitor an access terminal location, a radio environment, or both; and

transmit an initial access probe of a subsequent access attempt at a default initial transmission power level in response to a sufficient change in the access terminal location, the radio environment, or both.

8. A method operational at an access terminal, comprising:

conducting a plurality of preceding access attempts, where each preceding access attempt comprises transmitting access probes at successively increasing power levels until an access probe is successful;

determining an initial transmission power level based at least in part on one or more parameters associated with at least some of the plurality of previously successful access probes; and

conducting a subsequent access attempt, where an initial access probe is transmitted at the determined initial transmission power level.

9. The method of claim 8, wherein determining the initial transmission power level based at least in part on one or more parameters associated with the plurality of successful access probes comprises:

determining the initial transmission power level based at least in part on an average power level of at least some of the plurality of previously successful access probes.

10. The method of claim 8, wherein determining the initial transmission power level based at least in part on one or more parameters associated with the plurality of successful access probes comprises:

determining the initial transmission power level based at least in part on a difference of an average open-loop power level associated with the plurality of previously successful access probes and an open-loop power level associated with the subsequent access attempt.

11. The method of claim 8, wherein determining the initial transmission power level based at least in part on one or more parameters associated with the plurality of successful access probes comprises:

determining an average power level (P_AP) of at least some of the plurality of previously successful access probes;

determining an average open-loop power level (R_OLsucc) associated with the plurality of previously successful access probes;

determining an open-loop power level (R_OLnew) associated with the subsequent access attempt; and

determining the initial transmission power level (P) from the equation P=P_AP+(R_OLsucc-R_OLnew).

12. The method of claim 8, further comprising:

determining whether the access terminal is mobile or at least substantially stationary;

transmitting the initial access probe of a subsequent access attempt at the determined initial transmission power level in response to determining the access terminal is at least substantially stationary; and

transmitting the initial access probe of a subsequent access attempt at a default initial transmission power level in response to determining the access terminal is mobile.

13. The method of claim 8, further comprising:

receiving a message instructing the access terminal to employ a particular initial transmission power level for a subsequent access attempt.

14. The method of claim 8, further comprising:

monitoring an access terminal location, a radio environment or both; and

transmitting an initial access probe of a subsequent access attempt at a default initial transmission power level in response to a sufficient change in the access terminal location, the radio environment, or both.

15. An access terminal, comprising:

means for conducting a plurality of preceding access attempts, where each preceding access attempt comprises transmitting access probes at successively increasing power levels until an access probe is successful;

means for determining an initial transmission power level based at least in part on one or more parameters associated with the plurality of previously successful access probes; and

means for conducting a subsequent access attempt, where an initial access probe is transmitted at the determined initial transmission power level.

16. A processor-readable medium comprising programming operational on an access terminal, which when executed by a processor, causes the processor to:

determine an initial transmission power level based at least in part on one or more parameters associated with a plurality of previously successful access probes; and

transmit an initial access probe of a subsequent access attempt, wherein the initial access probe is transmitted at the determined initial transmission power level.

17. A network node, comprising:

a communications interface;

a storage medium; and

a processing circuit coupled to the communications interface and the storage medium, the processing circuit adapted to;

receive one or more access probes from an access terminal; and

send via the communications interface a message instructing the access terminal to employ a particular initial transmission power level for a subsequent access attempt.

18. The network node of claim 17, wherein the processing circuit is further adapted to:

send via the communications interface an access parameter message prior to receiving one or more access probes, wherein the access parameter message is adapted to indicate an initial transmission power level to be employed for access attempts and a power increment value.

19. The network node of claim 17, wherein at least one of the one or more received access probes comprises an initial access probe transmitted at a power level based at least in part on one or more parameters associated with a plurality of previously successful access probes.

20. The network node of claim 17, wherein the message instructing the access terminal to employ the particular initial transmission power level comprises an access parameter message.

21. The network node of claim 17, wherein a value defining the particular initial transmission power level is included in the message instructing the access terminal to employ the particular initial transmission power level.

22. The network node of claim 17, wherein the particular initial transmission power level comprises a default value.

23. A method operational at a network node, comprising:

receiving one or more access probes from an access terminal; and

transmitting a message instructing the access terminal to employ a particular initial transmission power level for a subsequent access attempt.

24. The method of claim 23, further comprising:

transmitting an access parameter message prior to receiving the one or more access probes, wherein the access parameter message is adapted to indicate an initial transmission power level and a power increment value to be employed for access attempts.

25. The method of claim 23, wherein receiving the one or more access probes from the access terminal comprises:

receiving an initial access probe transmitted at a power level based at least in part on one or more parameters associated with a plurality of previously successful access probes.

26. The method of claim 23, wherein transmitting the message instructing the access terminal to employ the particular initial transmission power level comprises:

transmitting the message comprising an indication to employ a default value as the particular initial transmission power level.

27. The method of claim 23, wherein transmitting the message instructing the access terminal to employ the particular initial transmission power level comprises:

transmitting the message comprising a value defining the particular initial transmission power level.

28. The method of claim 23, wherein transmitting the message instructing the access terminal to employ the particular initial transmission power level comprises:

transmitting an access parameter message including an indicator adapted to instruct the access terminal to employ the particular initial transmission power level.

29. A network node, comprising:

means for receiving one or more access probes from an access terminal; and

means for transmitting a message instructing the access terminal to employ a particular initial transmission power level for a subsequent access attempt.

30. The network node of claim 29, further comprising:

means for transmitting an access parameter message prior to receiving the one or more access probes, wherein the access parameter message is adapted to indicate an initial transmission power level and a power increment value to be employed for access attempts.

31. A processor-readable medium comprising programming operational on a network node, which when executed by a processor, causes the processor to:

receive one or more access probes from an access terminal; and

send a message instructing the access terminal to employ a particular initial transmission power level for a subsequent access attempt.