Client balancing in wireless networks
View Patent ↗Client balancing in a wireless digital network comprising a plurality of access nodes connected to a controller. Access nodes collect client density information and periodically report that client density information to the controller. The controller uses the client density information from the access nodes to compute Virtual RF Neighborhoods, identifying Virtual RF neighboring access nodes. Two access nodes are Virtual RF neighbors if a client which can connect to one access node can also connect to the other access node. The controller then identifies which nodes are overloaded by comparing the client loading of a target access node to the client loading of its Virtual RF neighbors. If an access node is identified as overloaded and selected for client balancing on a particular channel, it will initially refuse new association requests from client devices on that channel.
1. A method of client balancing in a wireless digital network comprising a plurality of access nodes connected to a controller, the method comprising:
identifying a Virtual RF neighborhood for each of the plurality of access nodes connected to the controller, the Virtual RF neighborhood of one access node being a subset of a RF neighborhood of the one access node, the RF neighborhood of the one access node including one or more access nodes that hear beacons from the one access node;
using the Virtual RF Neighborhood information for a target access node to determine if the target access node is overloaded; and
enabling client load balancing on the target access node if the target access node is overloaded, the target access node being overloaded if a load on the target access node exceeds a load in the Virtual RF neighborhood by a first predetermined threshold, whereby the target access node initially rejects new association requests from a wireless client;
wherein the step of identifying the Virtual RF neighborhood comprises the steps of:
collecting for a predetermined period of time client density data in each of the plurality of access nodes connected to the controller,
sending the client density data from the each of the plurality of access nodes to the controller on a periodic basis, and
computing at the controller the Virtual RF neighborhoods for each of the plurality of the access nodes by: selecting the client density data for pairs of access nodes, and testing the pairs of client density data to see if the client density overlap between the pairs of client density data exceeds a second predetermined threshold, and identifying the pair of access nodes as Virtual RF neighbors if the second threshold is exceeded.
2. The method of claim 1 where the step of determining if an access node is overloaded comprises:
selecting, at the controller, an access node as the target node,
computing at the controller a loading figure for the target node and those nodes which are Virtual RF neighbors of the target node, and
enabling or disabling client load balancing on the target node based on the load figure of the target node in comparison to the load figures of other access nodes in the target node's Virtual RF neighborhood.
3. The method of claim 1 where the step of initially rejecting new association requests from a wireless client by the target node further comprises:
if the wireless client has been rejected two or more times by an access node connected to the controller, accept the client association request at the target node,
if the client has been rejected once by the target node and sends a further association request to the target node, accept the client association request to the target node, and
if the association request is the first one to the target node, reject the request.
4. The method of claim 3 where the step of rejecting the request further comprises signaling a “resource constrained” code in the rejection.