Integrated power control and congestion control in a communication system

• US 6,128,506 A
• Filed: 09/24/1997
• Issued: 10/03/2000
• Est. Priority Date: 09/24/1997
• Status: Expired due to Term

• Current Assignee: Telefonaktiebolaget LM Ericsson
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Persson, Magnus, Knutsson, Jens
• Primary Examiner(s): Tsang, Fan
• Assistant Examiner(s): Jama, Isaak R.
• Application Number:
  US08/937,018
• Time in Patent Office: 1,105 Days
• Field of Search: 455/504, 455/505, 455/522, 455/69, 455/67.1, 455/67.3, 455/13.4, 455/453, 455/442, 370/318, 370/278, 370/333, 375/296, 375/297, 375/219
• US Class Current: 455/522
• CPC Class Codes: H04W 52/24 using SIR [Signal to Interference Ratio] or other wireless path parameters
• CPC Class Codes: H04W 52/343 taking into account loading or congestion level

Abstract

A method of stabilizing a communication system having base stations and mobile stations using integrated control of both signal transmission power levels and signal congestion levels. In particular, the method includes measuring a quality such as a signal to interference ratio of a signal transmitted from a mobile station to a base station and measuring a total received signal power at the base station. The signal transmission power of the mobile station is changed based on comparisons of the measured signals with predetermined threshold values. When the measured total received signal power at the base station exceeds the corresponding predetermined threshold value, a congestion control algorithm is executed to reduce the signal congestion level.

Claims

1. A method of controlling a communication system having base stations and mobile stations, comprising the steps of:

controlling signal transmission power of at least one mobile station in the system based on a signal traffic congestion in the system, wherein the step of controlling signal transmission power comprises;

measuring a quality of a signal transmitted from one of the mobile stations to one of the base stations;

comparing the measured signal quality with a first threshold value SIR^t ;

measuring a received signal power P_r at the one base station;

comparing the measured signal power P_r with a second threshold value P^t ; and

changing the signal transmission power of the one mobile station based on the comparisons of the measured signal quality with the first threshold value SIR^t and the measured signal power with the second threshold value P_r ;

wherein

the signal transmission power of the one mobile station is increased when a) (SIR_m /SIR^t)<

1 and P_r <

P^t, or b) (SIR_m /SIR^t)((P_r /P^t))<

1 and P_r >

P^t, where

SIR_m is a signal to interference ratio measured at the one base station of a signal transmitted from the one mobile station;

SIR^t is a predetermined signal to interference ratio threshold value;

P_r is a total signal power received at the one base station;

P^t is a predetermined total received signal power threshold value; and

n is greater than zero; and

controlling the sign traffic congestion in the system based on the comparison of the measured signal power with the second threshold value P^t, wherein the step of controlling congestion is performed when P_r >

P^t and comprises the steps of;

selecting a signal transmission between a first mobile station and a first base station;

performing at least one of lowering a bit rate of the selected signal transmission, executing an interfrequency handover of the selected signal transmission, and terminating the selected signal mission; and

repeating the steps of selecting and performing until P_r <

P^t.

2. The method of claim 1, wherein n is greater than or to 0.2 and less than or equal to 0.3.

3. The method of claim 1, wherein the signal transmission is selected based on whether delivery of data via the signal transmission is desired in real time.

4. The method of claim 1, wherein the step of performing is prioritized such that lowering the bit rate of the signal transmission and executing an interfrequency handover are preferred over terminating the selected signal transmission.

5. The method of claim 1, wherein the step of performing is prioritized such that lowering the bit rate of the signal transmission is preferred over executing an interfrequency handover.

6. An apparatus for stabilizing a communication system having base stations and mobile stations, comprising:

means for stabilizing a power vector of the system based on signal traffic congestion in the system, including

means for measuring a total signal power pr received at one of the base stations;

means for comparing the measured signal power P_r with a first threshold value P^t ;

means for measuring a quality SIR_m of a signal transmitted from one of the mobile stations to the one base station;

means for comparing the measured quality SIR_m with a second threshold value SIR^t ; and

means for changing the signal transmission power of the one mobile station based on the comparisons of the measured values with the threshold values, by increasing the signal transmission power of the one mobile station when a) (SIR_m /SIR^t)<

1 and P_r <

P^t, or b) (SIR_m /SIR^t)((P_r /P^t)ⁿ)<

1 and P_r >

P^t, where

SIR_m is a signal to interference ratio measured at the one base station of a signal transmitted from the one mobile station;

SIR^t is a predetermined signal to interference ratio threshold value;

P_r is a total signal power received at the one base station;

P^t is a predetermined total received signal power threshold value; and

n is greater than zero; and

means for reducing congestion in the system from a first level to a second level when P_r >

P^t, by selecting a signal transmission between a first mobile station and a first base station and performing at least one of a) lowering a bit rate of the selected signal transmission, b) performing an interfrequency handover of the selected signal transmission, and c) terminating the selected signal transmission, until P_r <

P^t.

7. The apparatus of claim 6, wherein the means for stabilizing comprises a processor located at one of the base stations.

8. The apparatus of claim 6, wherein the means for reducing congestion comprises a processor located at one of the stations.