System and method for reverse link overload control

• US 7,173,904 B1
• Filed: 09/23/1999
• Issued: 02/06/2007
• Est. Priority Date: 09/23/1999
• Status: Expired due to Term

• Current Assignee: Lucent Technologies, Inc. (Nokia Corporation)
• Original Assignee: Lucent Technologies, Inc. (Nokia Corporation)
• Inventors: Kim, Kyoung
• Primary Examiner(s): HSU, ALPUS
• Application Number:
  US09/401,326
• Time in Patent Office: 2,693 Days
• Field of Search: 370/320, 370/335, 370/342, 370/441, 370/230, 370/235, 370/252, 370/253, 370/331, 370/332, 370/389, 370/395.1, 370/395.2, 370/329, 445/67.1, 445/423, 445/450, 445/452.1, 445/452.2, 445/453, 445/522, 445/67.11
• US Class Current: 370/230
• CPC Class Codes: H04W 28/16 Central resource management; Negotiation of resources or communication parameters, e.g. negotiating bandwidth or QoS [Quality of Service]
• CPC Class Codes: H04W 72/52 based on load

Abstract

A system and method for controlling call admission in a wireless communications network recursively estimates reverse link load levels as a function of changes in base station receive power and/or the number of mobiles served in the cell/sector. In one implementation, a call admission controller utilizes multiple load level estimating methods, whereby a first method estimates load as a function of changes in base station receive power and changes in the number of served mobiles. The call admission controller uses a second method to recursively update load level estimates as proportionally changing with number of users. The call admission controller may utilize a third estimate method as an accuracy check based on a changes in base station receive power measurements. The call admission controller outputs a call blocking command when load level estimates exceed a threshold to avoid cell/sector overload conditions and network instability.

Claims

1. A method of controlling call admission in a communications network, comprising:

calculating a load level as a function of at least one of a difference between a current measured power and a previous measured power and a difference between a current number of users and a previous number of users; and

controlling call admission based on the calculated load level, wherein said calculating step recursively calculates updated load levels.

2. A method of controlling call admission in a communications network, comprising:

calculating a load level as a function of at least one of a difference between measured powers over time and a difference between a number of users over time; and

controlling call admission based on the calculated load level, wherein said calculating step estimates load level as a function of a measured difference between powers over time and a difference between the number of users over time.

3. The method of claim 2, wherein said calculating step estimates load level, L_new, by solving:

4. A method of controlling call admission in a communications network, comprising:

calculating a load level as a function of at least one of previous and current measured powers and previous and current number of users; and

controlling call admission based on the calculated load level,

wherein said calculating step recursively updates the calculated load level as a function of previous and current number of users.

5. The method of claim 4, wherein said calculating step recursively updates the calculated load level, L_new, by solving:

6. A method of controlling call admission in a communications network, comprising:

calculating a load level as a function of at least one of measured powers and previous and current number of users; and

controlling call admission based on the calculated load level,

wherein said calculating step recursively updates the calculated load level as a function of previous and current measured powers.

7. The method of claim 6, wherein said calculating step recursively updates the calculated load level, L_new, by solving:

8. The method of claim 6, further comprising:

verifying the calculated load level before using the calculated load level in said controlling step.

9. The method of claim 8, wherein said verifying step calculates an estimated power measurement, P_new′

, based on the calculated load level, L_new, by solving;

10. The method of claim 9, wherein, when said verifying step indicates that the P_new′

is not sufficiently close to P_new, said calculating step recursively updates the calculated load level, L_new by solving;

11. A system of controlling call admissions in a communications network, comprising:

load calculating means for calculating a load level as a function of at least one of previous and current measured powers and previous and current number of users; and

control means for controlling call admission based on the calculated load level,

wherein said load calculating means recursively updates the calculated load levels.

12. The system of claim 11, further comprising:

input means for receiving power measurements and number of user values.

13. A system of controlling call admissions in a communications network, comprising:

load calculating means for calculating a load level as a function of at least one of a difference between measured powers over time and a difference between a number of users over time; and

control means for controlling call admission based on a load level the calculated load level, wherein said load calculating means estimates load level as a function of a difference between measured powers over time and a difference between the number of users over time.

14. The system of claim 13, wherein said load calculating means estimates load level, L_new, by solving:

15. A system of controlling call admissions in a communications network, comprising:

load calculating means for calculating a load level as a function of at least one of previous and current measured powers and previous and current number of users; and

control means for controlling call admission based on the calculated load level,

wherein said load calculating means recursively updates the calculated load level as a function of previous and current number of users.

16. The system of claim 15, wherein said load calculating means recursively updates the calculated load level, L_new, by solving:

17. A system of controlling call admissions in a communications network, comprising:

load calculating means for calculating a load level as a function of previous and current measured powers and previous and current number of users; and

control means for controlling call admission based on the calculated load level,

wherein said load calculating means recursively updates the calculated load level as a function of previous and current measured powers.

18. The system of claim 17, wherein said load calculating means recursively updates the calculated load level, L_new, by solving:

19. The system of claim 17, further comprising:

verifying means for verifying the calculated load level before said control means uses the calculated load level.

20. The system of claim 19, wherein said verifying means calculates an estimated power measurement, P_new′

, based on the calculated load level, L_new, by solving;

21. The system of claim 20, wherein, when said verifying means indicates that the P_new′

is not sufficiently close to P_new, said calculating means recursively updates the calculated load level L_new by solving;