Reservation multiple access

• US 6,256,301 B1
• Filed: 10/15/1998
• Issued: 07/03/2001
• Est. Priority Date: 10/15/1998
• Status: Expired due to Term

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Walton, Rod, Tiedemann, Edward G. Jr., Howard, Steven J., Wallace, Mark S.
• Primary Examiner(s): Kizou, Hassan
• Assistant Examiner(s): Previl, Daniel
• Application Number:
  US09/173,572
• Time in Patent Office: 992 Days
• Field of Search: 370/335, 370/342, 370/348, 370/329, 370/321, 370/322, 370/443, 370/461, 370/462, 340/825.5, 340/825.08, 340/825.03, 375/200
• US Class Current: 370/342
• CPC Class Codes: H04W 74/002 Transmission of channel access control information
• CPC Class Codes: H04W 74/0866 using a dedicated channel for access

Abstract

A mobile station accesses a base station by randomly selecting a first reverse link common control channel from a set of random access channels. The mobile station transmits a request portion of an access probe over the first reverse link common control channel. The request portion is subject to collision with other signals. The request portion comprises a hash identification which is derived from a uniquely identifying number using a hash function. The hash identification quasi-uniquely identifies the mobile station. The mobile station receives a channel assignment message from the base station designating the hash identification and a reserved access channel. The reserved access channel provides communication with a low probability of contention. The mobile station transmits a message portion of the access probe over the reserved access channel.

Claims

1. A method of accessing a base station from a mobile station, comprising the steps of:

randomly selecting a first reverse link common control channel from a set of random access channels subject to contention;

transmitting a request portion of an access probe over said first reverse link common control channel, said request portion comprising an identification which quasi-uniquely identifies said mobile station;

receiving a channel assignment message from said base station designating said identification and a reserved access channel, said reserved access channel providing communication with a low probability of contention; and

transmitting a message portion of said access probe over said reserved access channel.

2. The method of claim 1, wherein said step of transmitting said message portion facilitates reception of said message portion by a plurality of sectors associated with a single base station.

3. The method of claim 1, wherein said step of transmitting said message portion facilitates reception of said message portion by a plurality of base stations.

4. The method of claim 1, wherein said message portion comprises an overhead message.

5. The method of claim 1, wherein said message portion comprises user data.

6. The method of claim 1, wherein said step of transmitting said message portion occurs at one of a set of available data rates.

7. The method of claim 1, wherein said message portion comprises a call origination message.

8. The method of claim 1, wherein said message portion is significantly longer than said request portion.

9. The method of claim 1, further comprising the step of determining said identification which quasi-uniquely identifies said mobile station from a unique identifying number associated with said mobile station using a hash function.

10. The method of claim 1, further comprising the step of randomly selecting said identification which quasi-uniquely identifies said mobile station.

11. The method of claim 1, wherein said channel assignment message specifies a wait period to be observed, and wherein the method further comprises the step of delaying said step of transmitting said message portion with reference to said wait period.

12. The method of claim 1, wherein said channel assignment message specifies a power control correction amount, and wherein the method further comprises the step of determining a power level at which to transmit said message portion with reference to said power control correction amount.

13. The method of claim 1, further comprising the steps of:

receiving a power control command over a forward link channel associated with said reserved access channel; and

responding to said power control command by increasing or decreasing a power level at which said mobile-station transmits said message portion.

14. The method of claim 13, wherein said forward link channel is expressly specified in said channel assignment message.

15. The method of claim 13, wherein said power control command is received from a plurality of sectors associated with a single base station.

16. The method of claim 13, wherein said power control command is received from a plurality of base stations.

17. A method of accessing a system from a mobile station, comprising the steps of:

randomly selecting a first reverse link common control channel from a set of random access channels that are subject to contention;

transmitting a request portion of an access probe over said first reverse link common control channel;

receiving a channel assignment message designating a reserved access channel, said reserved access channel providing communication with a low probability of contention;

transmitting a message portion of said access probe over said reserved access channel;

receiving a power control command over a forward link channel associated with said reserved access channel; and

responding to said power control command by increasing or decreasing a power level at which said step of transmitting said message portion is executed.

18. An apparatus for accessing a system from a mobile station, comprising:

means for randomly selecting a first reverse link common control channel from a set of random access channels that are subject to contention;

means for transmitting a request portion of an access probe over said first reverse link common control channel, said request portion comprising an identification which quasi-uniquely identifies said mobile station;

means for receiving a channel assignment message designating said identification and a reserved access channel, said reserved access channel providing communication with a low probability of contention; and

means for transmitting a message portion of said access probe over a reserved access channel.

19. The apparatus of claim 18, wherein said means for transmitting said message portion is configured to allow demodulation of said message portion by a plurality of sectors associated with a single base station.

20. The apparatus of claim 18, wherein said means for transmitting said message portion is configured to allow demodulation of said message portion by a plurality of base stations.

21. The apparatus of claim 18, wherein said means for transmitting said message portion operates at one of a set of available data rates.

22. The apparatus of claim 18, wherein said message portion is significantly longer than said request portion.

23. The apparatus of claim 18, further comprising means for determining said identification which quasi-uniquely identifies said mobile station from a unique identifying number associated with said mobile station using a hash function.

24. The apparatus of claim 18, further comprising means for randomly selecting said identification which quasi-uniquely identifies said mobile station.

25. The apparatus of claim 18, wherein said channel assignment message specifies a wait period, and wherein the apparatus further comprises means for delaying transmission of said message portion with reference to said wait period.

26. The apparatus of claim 18, further comprising:

means for receiving a power control command over a forward link channel associated with said reserved access channel; and

means for responding to said power control command by increasing or decreasing a power level at which said mobile station transmits said message portion.

27. The apparatus of claim 26, wherein said means for receiving said power control command comprises means for receiving said power control command from a plurality of sectors associated with a single base station.

28. The apparatus of claim 26, wherein said means for receiving said power control command comprises means for receiving said power control command from a plurality of base stations.

29. A mobile station, comprising:

a controller configured to randomly select a first reverse link common control channel from a set of random access channels that are subject to contention;

a modulator coupled to said controller, said modulator being configured to modulate a request portion of an access probe, said request portion comprising an identification which quasi-uniquely identifies said mobile station;

a radio frequency signal processing unit coupled to said modulator, said signal processing unit being configured to transmit said request portion over said first forward link common control channel and configured to receive a channel assignment message designating said identification and a reserved access channel, said reserved access channel providing communication with a low probability of contention; and

a demodulator coupled to said radio frequency signal processing unit and said controller, said demodulator configured to demodulate said channel assignment message;

said modulator further configured to modulate a message portion of said access probe;

said radio frequency signal processing unit further configured to transmit said message portion over said reserved access channel.

30. The mobile station of claim 29, wherein said controller is further configured to derive said identification which quasi-uniquely identifies said mobile station from a uniquely identifying number associated with said mobile station using a hash function.

31. The mobile station of claim 29, wherein said controller is further configured to randomly select said identification which quasi-uniquely identifies said mobile station.

32. The mobile station of claim 29, wherein said radio frequency signal processing unit comprises a power control apparatus configured to receive a power control command over a forward link channel and configured to respond thereto by increasing or decreasing a power level at which said mobile station transmits said message portion.

33. The mobile station of claim 32, wherein said radio frequency signal processing unit is further configured to receive said power control command from a plurality of sectors associated with a single base station.

34. The mobile station of claim 32, wherein said radio frequency signal processing unit is further configured to receive said power control command from a plurality of base stations.

35. A method of system access, comprising the steps of:

receiving a request portion of an access probe over a first forward link common control channel selected from among a set of random access channels which provide communication subject to contention, said request portion comprising an identification which quasi-uniquely identifies a mobile station;

transmitting a channel assignment message designating said identification and a reserved access channel, said reserved access channel providing communication with a low probability of contention; and

receiving a message portion of said access probe over said reserved access channel from said mobile station.

36. The method of claim 35, wherein said step of receiving said message portion is performed by a plurality of sectors associated with a base station.

37. The method of claim 35, wherein said channel assignment message specifies a wait period to be observed before said step of receiving said message portion is executed.

38. The method of claim 35, further comprising the step of determining a power correction amount based upon a signal quality level at which said request portion is received and wherein said channel assignment message specifies said power control correction amount to be used by said mobile station to transmit said message portion.

39. The method of claim 35, further comprising the step of transmitting a power control command over a forward link channel based upon a signal quality level at which said message portion is received during said step of receiving said message portion.

40. The method of claim 39, further comprising the step of transmitting a power control command through a plurality of sectors associated with said base station, said transmitting step being performed in response to a signal quality level at which said message portion is received.

41. An apparatus for obtaining system access, comprising:

means for receiving a request portion of an access probe over a first forward link common control channel selected from among a set of random access channels which provide communication subject to contention, said request portion comprising an identification which quasi-uniquely identifies a mobile station;

means for transmitting a channel assignment message designating said identification and a reserved access channel, said reserved access channel providing communication with a low probability of contention; and

means for receiving a message portion of said access probe over said reserved access channel from said mobile station.

42. The apparatus of claim 41, wherein said means for receiving said message portion comprises means for receiving said message portion through a plurality of sectors associated with a base station.

43. The apparatus of claim 41, further comprising means for determining a power correction amount based upon a signal quality level at which said request portion is received and wherein said channel assignment message specifies an amount of said power control correction to be used by said mobile station to transmit said message portion.

44. The apparatus of claim 41, further comprising means for transmitting a power control command to said mobile station over a forward link channel based upon a signal quality level at which said message portion is received.

45. The apparatus of claim 41, further comprising means for transmitting a power control command to said mobile station through a plurality of sectors associated with a base station based upon a signal quality level at which said message portion is received.

46. A base station, comprising:

a signal processing unit configured to receive a request portion of an access probe over a first forward link common control channel selected from among a set of random access channels providing communication subject to contention, said request portion comprising an identification which quasi-uniquely identifies a mobile station; and

a signal generation unit configured to transmit a channel assignment message designating said identification and designating a reserved access channel, said reserved access channel providing communication with a low probability of contention;

said signal processing unit further configured to receive a message portion of said access probe over a reserved access channel from said mobile station.

47. The base station of claim 46, further comprising a plurality of demodulators associated with a plurality of sectors within said base station, said demodulator being each coupled to said signal processing unit, and wherein said message portion is received through more than one of said plurality of demodulators.