Wireless communications handoff method and system employing such

• US 20030176189A1
• Filed: 01/23/2003
• Published: 09/18/2003
• Est. Priority Date: 01/23/2002
• Status: Active Grant

• Current Assignee: AT&T Mobility II LLC (AT&T, Inc.)
• Original Assignee: Leap Wireless International Incorporated (AT&T, Inc.)
• Inventors: Liddell, Philip Wayne, Odedina, Samuel Bandele, Merson, Andrew Charles
• Granted Patent: US 7,359,707 B2
• Time in Patent Office: Days
• US Class Current: 455/436
• CPC Class Codes: H04W 36/06 Reselecting a communication resource in the serving access point

Abstract

A method for reducing a delay in a wireless communications system resulting from a handoff while mitigating a risk of premature termination of wireless communications, the method includes comparing data indicative of actual use of the wireless communications systems to at least one predetermined criteria. If the comparing determines a sector pairing in the wireless communications system to be statistically significant for purposes of recommending at least one search window setting, at least one value related with a distance associated with the sector pairing may be used to automatically determine a corresponding signal delay. If the corresponding signal delay exceeds a prior determined signal delay, a recommended search window setting may be determined using the corresponding signal delay.

Claims

1. A method for reducing a delay in a wireless communications system resulting from a handoff while mitigating a risk of premature termination of wireless communications, said method comprising:

identifying a plurality of communications sectors, each of said sectors having a geographic relationship with respect to each other of said sectors;

selecting at least two of said sectors based upon said geographic relationship between said at least two sectors;

determining a wireless communications timing delay for said at least two sectors;

estimating a signal delay for said at least two sectors; and

,

determining at least one search window associated with at least said at least two sectors using said determined timing delay and estimated signal delay.

2. The method of claim 1, wherein said determining at least one search window comprises summing said determined timing delay and estimated signal delay.

3. The method of claim 2, wherein said determining at least one search window further comprises comparing said summed timing and signal delays to predetermined criteria.

4. The method of claim 1, further comprising reducing said summed delays.

5. The method of claim 4, wherein said reducing is dependent upon at least one reduction factor.

6. The method of claim 5, wherein said reduction factor is at least partially based upon a geographic topography.

7. The method of claim 5, wherein said reduction factor is at least partially based upon a layout of at least some of said plurality of sectors.

8. The method of claim 1, wherein said wireless communications system comprises a multiple access communications network.

9. The method of claim 8, wherein said multiple access communications network comprises a CDMA communications network.

10. The method of claim 8, wherein said multiple access communications network comprises a WCDMA communications network.

11. The method of claim 1, wherein said multiple access communications network comprises a TDMA communications network.

12. The method of claim 1, wherein said multiple access communications network comprises a FDMA communications network.

13. The method of claim 1, wherein said wireless communications system comprises a GSM communications network.

14. The method of claim 1, wherein said wireless communications system comprises an AMPS communications network.

39. The method of claim 8, wherein said multiple access communications network comprises at least one of:

a CDMA communications network, a WCDMA communications network, a TDMA communications network, an FDMA communications network, a GSM communications network and an AMPS communications network.

15. A computer program product embodied on a computer-readable storage medium for reducing a delay in a wireless communications system resulting from a handoff while mitigating a risk of premature termination of wireless communications, the computer program product comprising:

code for receiving data indicative of a plurality of communications sectors, each of said sectors having a geographic distance relationship with respect to each other of said sectors;

code for selecting at least two of said sectors based upon said geographic relationship between said at least two sectors;

code for determining a wireless communications timing delay for said at least two sectors;

code for estimating a signal delay for said at least two sectors; and

,

code for determining at least one search window associated with at least said at least two sectors using said determined timing delay and estimated signal delay.

16. The computer program product of claim 15, wherein said code for determining at least one search window comprises code for summing said determined timing delay and estimated signal delay.

17. The computer program product of claim 16, wherein said code for determining at least one search window further comprises code for comparing said summed timing and signal delays to predetermined criteria.

18. The computer program product of claim 15, further comprising code for reducing said summed delays.

19. The computer program product of claim 18, wherein said reducing is dependent upon at least one reduction factor.

20. The computer program product of claim 19, wherein said reduction factor is at least partially based upon a geographic topography.

21. The computer program product of claim 19, wherein said reduction factor is at least partially based upon a layout of at least some of said plurality of sectors.

22. The computer program product of claim 19, further comprising code for causing said reduction factor to be stored so as to be usable by said computer program product

23. The computer program product of claim 15, wherein said wireless communications system comprises at least one of:

a CDMA communications network, a WCDMA communications network, a TDMA communications network, an FDMA communications network, a GSM communications network, and an AMPS communications network.

24. A wireless communications system comprising a plurality of neighbor lists, each of said neighbor lists being formed in accordance with a method comprising:

identifying a plurality of communications sectors, each of said sectors having a geographic distance relationship with respect to each other of said sectors;

selecting at least two of said sectors based upon said geographic relationship between said at least two sectors;

determining a wireless communications timing delay for said at least two sectors;

estimating a signal delay for said at least two sectors; and

,

determining at least one search window associated with at least said at least two sectors using said determined timing delay and estimated signal delay.

25. The system of claim 24, wherein said determining at least one search window comprises summing said determined timing delay and estimated signal delay.

26. The system of claim 25, wherein said determining at least one search window further comprises comparing said summed timing and signal delays to predetermined criteria.

27. The system of claim 24, further comprising reducing said summed delays.

28. The system of claim 27, wherein said reducing is dependent upon at least one reduction factor.

29. The system of claim 28, wherein said reduction factor is at least partially based upon a geographic topography.

30. The system of claim 28, wherein said reduction factor is at least partially based upon a layout of at least some of said plurality of sectors.

31. The system of claim 24, wherein said wireless communications system comprises at least one of:

a CDMA communications network, a WCDMA communications network, a TDMA communications network, an FDMA communications network, a GSM communications network, and an AMPS communications network.

32. A method for reducing a delay in a wireless communications system resulting from a handoff while mitigating a risk of premature termination of wireless communications, said method comprising:

identifying a plurality of communications sectors, each of said sectors having a geographic relationship with respect to each other of said sectors;

automatically determining whether a number of handoffs between at least two of said plurality of sectors exceeds a threshold;

automatically determining a distance between said at least two sectors using said geographic relationship between said at least two sectors and converting said distance to a corresponding signal delay; and

,

if said number of handoffs exceeds said threshold and said converted corresponding signal delay exceeds a prior determined signal delay, recommending a minimum search window based upon said converted corresponding signal delay.

33. The method of claim 32, wherein said recommending comprises comparing said converted corresponding signal delay to predetermined criteria.

34. The method of claim 32, further comprising reducing said converted corresponding delay.

35. The method of claim 34, wherein said reducing is dependent upon at least one reduction factor.

36. The method of claim 35, wherein said reduction factor is at least partially based upon a geographic topography.

37. The method of claim 35, wherein said reduction factor is at least partially based upon a layout of at least some of said plurality of sectors.

38. The method of claim 32, wherein said wireless communications system comprises a multiple access communications network.

40. A computer program product embodied on a computer-readable storage medium for reducing a delay in a wireless communications system resulting from a handoff while mitigating a risk of premature termination of wireless communications, the computer program product comprising:

code for storing data indicative of a plurality of communications sectors, each of said sectors having a geographic relationship with respect to each other of said sectors;

code for automatically determining whether a number of handoffs between at least two of said plurality of sectors exceeds a threshold;

code for automatically determining a distance between said at least two sectors using said geographic relationship between said at least two sectors and converting said distance to a corresponding signal delay; and

,

code for recommending a minimum search window based upon said converted corresponding signal delay if said number of handoffs exceeds said threshold and said converted corresponding signal delay exceeds a prior determined signal delay.

41. The computer program product of claim 40, further comprising code for automatically accessing data indicative of said geographic relationship between said at least two sectors.

42. The computer program product of claim 41, further comprising code for storing said data indicative of said geographic relationship between said at least two sectors.

43. A method for reducing a delay in a wireless communications system resulting from a handoff while mitigating a risk of premature termination of wireless communications, said method comprising:

comparing data indicative of actual use of said wireless communications systems to at least one predetermined criteria;

if said comparing determines a sector pairing in said wireless communications system to be statistically significant for purposes of recommending at least one search window setting, using at least one value related with a distance associated with said sector pairing to automatically determine a corresponding signal delay; and

,

if said corresponding signal delay exceeds a prior determined signal delay, determining a recommended search window setting using said corresponding signal delay.