Method and apparatus for dynamic load balancing using handoff

• US 5,796,722 A
• Filed: 05/17/1996
• Issued: 08/18/1998
• Est. Priority Date: 05/17/1996
• Status: Expired due to Term

• Current Assignee: Motorola Solutions, Inc.
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Stolyar, Aleksandr L., Kotzin, Michael D., Fleming, Philip J.
• Primary Examiner(s): MARCELO, MELVIN C
• Application Number:
  US08/649,093
• Time in Patent Office: 823 Days
• Field of Search: 370/252, 370/317-321, 370/329-335, 370/342, 370/343, 370/437, 370/465, 455/33.1, 455/33.2, 455/34.1, 455/34.2, 455/63, 455/67.3, 455/436, 455/438, 455/439, 455/442, 455/447, 455/453
• US Class Current: 370/252
• CPC Class Codes: H04W 28/26 Resource reservation
• CPC Class Codes: H04W 36/08 Reselecting an access point
• CPC Class Codes: H04W 36/20 for optimising the interference level

Abstract

To mitigate the adverse affects of the load imbalance phenomenon prevalent in spread spectrum, multi-carrier wireless communication systems, the system beneficially employs the use of handoff as a means for balancing the call traffic (commonly referred to as "load") among a plurality of carriers within the communication system. The multi-carrier wireless communication system monitors a plurality of metrics corresponding to the loading of each of the plurality of carriers in the communication system and, based upon the metrics, will handoff call traffic to and between the plurality of carriers, thereby mitigating the adverse effects associated with the load imbalance, in accordance with the invention.

Claims

1. A method of dynamically balancing call traffic (load) of a plurality of subscribers among a plurality of carriers in a multicarrier wireless communication system, the plurality of subscribers in communication with a base-station via the plurality of carriers, the method comprising the steps of:

classifying each subscriber of the plurality of subscribers within the communication system into a class category based on a metric corresponding to each of the plurality of subscribers; and

balancing the load of the plurality of subscribers among the plurality of carriers based on the class category of each of the plurality of subscribers.

2. The method of claim 1, wherein the step of balancing comprises the steps of:

determining the class category of each subscriber of the plurality of subscribers operating within the communication system;

distributing a subset of subscribers from each class category among each of the plurality of carriers.

3. A method of dynamically balancing call traffic (load) among a plurality of carriers in a multi-carrier wireless communication system, the method comprising:

monitoring a load metric for each of the plurality of carriers within the communication system;

calculating a location anticipation metric for each subscriber of a plurality of subscribers operating within the communication system; and

balancing the load among the plurality of carriers based on the load metric and the location anticipation metric.

4. The method of claim 3, wherein the location anticipation metric is comprised of a subscriber'"'"'s location, speed and direction of travel.

5. The method of claim 4, the step of balancing further comprising:

determining that a load metric corresponding to a first carrier of the plurality of carriers has reached a threshold;

calculating a location anticipation metric corresponding to a subscriber of the plurality of subscribers which indicates that the subscriber is a suitable candidate subscriber; and

performing a handoff of the suitable candidate subscriber from the first carrier to a second carrier based on the steps of determining and calculating.

6. An apparatus for dynamically balancing call traffic (load) among a plurality of carriers in a multi-carrier wireless communication system, the apparatus comprising:

means for monitoring a load metric for each of the plurality of carriers within the communication system;

means for calculating a location anticipation metric for each subscriber of a plurality of subscribers operating within the communication system; and

means for balancing the load among the plurality of carriers based on the load metric and the location anticipation metric.

7. The apparatus of claim 6, wherein the location anticipation metric is comprised of a subscriber'"'"'s location, speed and direction of travel.

8. The apparatus of claim 6, wherein the means for balancing further comprises:

means for determining that a load metric corresponding to a first carrier of the plurality of carriers has reached a threshold;

means for calculating a location anticipation metric corresponding to a subscriber of the plurality of subscribers which indicates that the subscriber is a suitable candidate subscriber; and

means for performing a handoff of the suitable candidate subscriber from the first carrier to a second carrier based on the steps of determining and calculating.