Claims
- 1. A method for processing random access requests in a mobile communications system, comprising the steps of:a mobile station transmitting a first random access request for receipt by a base station; said mobile station determining if said first random access request has been received by said base station; and if said mobile station determines that said first random access request has not been received, randomly selecting a signature code from a plurality of signature codes, associating said selected signature code with a signature field for said first random access request, and re-transmitting said first random access request with said signature field including said selected signature code.
- 2. The method of claim 1, wherein said selected signature code is orthogonal to at least one of said plurality of signature codes.
- 3. The method of claim 1, wherein said determining step comprises the step of waiting a predetermined time for an acknowledgment message from said base station.
- 4. The method of claim 3, wherein said predetermined time comprises a predetermined time-out interval.
- 5. The method of claim 3, wherein said predetermined time is determined by at least one network performance factor.
- 6. The method of claim 3, wherein said predetermined time is randomly selected by said mobile station.
- 7. The method of claim 6, wherein said predetermined time is randomly selected from a time-out interval {0, Td}.
- 8. The method of claim 1, wherein said signature field comprises a preamble.
- 9. The method of claim 1, wherein said mobile communications system comprises a spread spectrum mobile communications system.
- 10. The method of claim 1, wherein said mobile communications system comprises a Code Division Multiple Access mobile communications system.
- 11. A system for processing random access requests in a mobile communications system, comprising:a base station; and a mobile station coupled to said base station by a radio air interface, said mobile station including: means for transmitting a first random access request for receipt by said base station; means for determining if said first random access request has been received by said base station; and means for randomly selecting a signature code from a plurality of signature codes, associating said selected signature code with a signature field for said first random access request, and re-transmitting said first random access request with said signature field including said selected signature code, if said mobile station determines that said first random access request has not been received.
- 12. The system of claim 11, wherein said selected signature code is orthogonal to at least one of said plurality of signature codes.
- 13. The system of claim 11, wherein said means for determining comprises means for waiting a predetermined time for an acknowledgment message from said base station.
- 14. The system of claim 13, wherein said predetermined time comprises a predetermined time-out interval.
- 15. The system of claim 13, wherein said predetermined time is determined by at least one network performance factor.
- 16. The system of claim 13, wherein said predetermined time is randomly selected by said mobile station.
- 17. The system of claim 16, wherein said predetermined time is randomly selected from a time-out interval {0, Td}.
- 18. The system of claim 11, wherein said signature field comprises a preamble.
- 19. The system of claim 11, wherein said mobile communications system comprises a spread spectrum mobile communications system.
- 20. The system of claim 11, wherein said mobile communications system comprises a Code Division Multiple Access mobile communications system.
RELATED APPLICATIONS
This application is a continuation-in-part of, and claims priority from U.S. patent application Ser. No. 08/847,655 now U.S. Pat. No. 6,163,533 to Esmailzadeh et al., which was filed Apr. 30, 1997 and is incorporated herein in its entirety.
This application is also related by subject matter to commonly-assigned-U.S. patent application Ser. No. 08/733,501, now U.S. Pat. No. 6,259,724 which was filed Oct. 18, 1996.
US Referenced Citations (1)
Number |
Name |
Date |
Kind |
6259724 |
Esmailzadeh |
Jul 2001 |
B1 |
Foreign Referenced Citations (2)
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Date |
Country |
0633671 |
Jan 1995 |
EP |
9818280 |
Apr 1998 |
WO |
Non-Patent Literature Citations (2)
Entry |
IEEE Journal on Selected Areas in Communications, USA, “Design Study for a CDMA-Based Third-Generation Mobile Radio System,” A. Baier et al., vol. 12, No. 4, May 1994, pp. 733-743, XP000588850. |
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Continuation in Parts (1)
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Number |
Date |
Country |
Parent |
08/847655 |
Apr 1997 |
US |
Child |
09/148224 |
|
US |