Centralized wireless LAN load balancing
A centralized wireless LAN load balancing mechanism is described herein. In one embodiment, in response to a request for entering a wireless network from a wireless station and forwarded from multiple access points (APs) of the wireless network, a network access device coupled to the multiple APs determines a load for each of the APs. The network access device then selects one of the APs based on the determined loads of the APs and instructs the selected AP to associate with the wireless station. The network access device further instructs the remaining APs to reject the request. Other methods and apparatuses are also described.
1. A method for load balancing a wireless area network, the method comprising:
receiving load data from a plurality of access points, each of the access points having received an entry request from a wireless client; and
executing instructions stored in memory, wherein execution of the instructions by a processor:
calculates a weighted load value for each access point by inputting the load data for each access point into a load balancing algorithm, wherein the load balancing algorithm includes the following variables:
a variance of a mean received signal strength indication (RSSI) of the access point, the variance considering the mean RSSI both with and without the wireless client taken into account, and
a quotient comparing the mean RSSI of the access point with the wireless client taken into account to the maximum possible RSSI for the access point;
compares the weighted load values of the access points to one another; and
selects one access point from among the plurality of access points to accept the entry request from the wireless client according to a predetermined category, wherein the predetermined category is based on the comparison of the weighted load values.
2. The method of claim 1 , wherein the load data for each access point is received at a network access device communicatively coupled to the access points and the load data indicates one or more of the following:
a quantity of wireless clients connected to the access point, and
an RSSI between the access point and the wireless client.
3. The method of claim 2 , wherein the network access device is a gateway device interfacing the wireless area network with another network.
4. The method of claim 2 , wherein the load balancing algorithm further includes a variable corresponding to a frame error rate (FER) of the access point.
5. The method of claim 4 , wherein the load data for each access point further indicates the FER of the access point.
6. The method of claim 5 , wherein the processor further instructs the selected access point to accept the entry request from the wireless client.
7. The method of claim 6 , wherein the processor further instructs each of the non-selected access points to affirmatively reject the entry request from the wireless client by sending a probe response.
8. The method of claim 7 , wherein the request received from the wireless client is an IEEE 802.11 compatible probe request message, the selected access point responds with an IEEE 802.11 compatible probe response message to accept the probe request, and the non-selected access points respond with an IEEE 802.11 compatible probe response message having one or more predetermined bits altered to reject the probe request.
9. The method of claim 8 , wherein the IEEE 802.11 compatible probe response message having the one or more altered predetermined bits indicates that the request has been rejected by access point, and the IEEE 802.11 compatible probe response message sent by the selected access point has one or more unaltered predetermined bits that indicates the request has been accepted by the access point.
10. The method of claim 7 , wherein the probe response is an IEEE 802.11 compatible probe response message having a privacy bit inverted.
11. A wireless area network load balancing system, the system comprising:
a network access device; and
a plurality of access points that receive a request from a wireless client to enter a wireless network that includes the access points, the access points communicatively coupled to the network access device through the wireless network, wherein the network access device balances the overall load on the wireless area network by:
receiving load data from each of the access points, the load data indicating a received signal strength indication (RSSI) between the access point and the wireless client and either of:
a quantity of wireless clients connected to the access point, and
a frame error rate (FER) of the access point; and
executing instructions stored in memory, wherein execution of the instructions by a processor:
calculates a weighted load value for each of the access points by inputting the load data for each access point into a balancing algorithm, wherein the balancing algorithm includes a variance of a mean RSSI of the access point, the variance considering the mean RSSI both with and without the wireless client taken into account, and one or more of the following variables:
a quotient comparing the mean RSSI of the access point with the wireless client taken into account to the maximum possible RSSI for the access point, and
the FER of the access point when the received load data includes the FER of the access point;
compares the weighted load values of the access points to one another;
selects one access point from among the plurality of access points to accept the entry request from the wireless client according to a predetermined category, wherein the predetermined category is based on the comparison of the weighted load values;
instructs the selected access point to accept the entry request from the wireless client; and
instructs each of the non-selected access points to reject the entry request from the wireless client.
12. A method for load balancing a wireless area network, the method comprising:
receiving load data from a plurality of access points in the wireless area network each access point having received an entry request from a wireless client, the load data for each access point received at a network access device communicatively coupled to the access points and indicating a received signal strength indication (RSSI) between the access point and the wireless client and either of:
a quantity of wireless clients connected to the access point, and
a frame error rate (FER) of the access point; and
executing instructions stored in memory, wherein execution of the instructions by a processor:
calculates a weighted load value for each of the access points by inputting the load data for each access point into a balancing algorithm, wherein the balancing algorithm includes a variance of a mean RSSI of the access point, the variance considering the mean RSSI both with and without the wireless client taken into account, and one or more of the following variables:
a quotient comparing the mean RSSI of the access point with the wireless client taken into account to the maximum possible RSSI for the access point, and
the FER of the access point when the received load data includes the FER of the access point;
compares the weighted load values of the access points to one another;
selects one access point from among the plurality of access points to accept the entry request from the wireless client according to a predetermined category, wherein the predetermined category is based on the comparison of the weighted load values;
instructs the selected access point to accept the entry request from the wireless client; and
instructs each of the non-selected access points to reject the entry request from the wireless client.
13. A method for load balancing a wireless area network, the method comprising:
receiving load data from a plurality of access points in the wireless area network, each access point having received an entry request from a wireless client, the load data for each access point received at a network access device communicatively coupled to the access points and indicating:
a frame error rate (FER) of the access point,
a quantity of wireless clients connected to the access point, and
a received signal strength indication (RSSI) between the access point and the wireless client; and
executing instructions stored in memory, wherein execution of the instructions by a processor:
calculates a weighted load value for each of the access points by inputting the load data for each access point into a balancing algorithm, wherein the balancing algorithm includes the following variables:
a variance of a mean RSSI of the access point, the variance considering the mean RSSI both with and without the wireless client taken into account,
a quotient comparing the mean RSSI of the access point with the wireless client taken into account to the maximum possible RSSI for the access point, and
the FER of the access point;
compares the weighted load values of the access points to one another;
selects one access point from among the plurality of access points to accept the entry request from the wireless client according to a predetermined category, wherein the predetermined category is based on the comparison of the weighted load values;
instructs the selected access point to accept the entry request from the wireless client; and
instructs each of the non-selected access points to reject the entry request from the wireless client.
14. A non-transitory machine-readable storage medium having embodied thereon executable code to cause a machine to perform a method for load balancing a wireless area network, the method comprising:
receiving load data from a plurality of access points in the wireless area network, each access point having received an entry request from a wireless client, the load data for each access point received at a network access device communicatively coupled to the access points and indicating:
a frame error rate (FER) of the access point,
a quantity of wireless clients connected to the access point, and
a received signal strength indication (RSSI) between the access point and the wireless client; and
executing instructions stored in memory, wherein execution of the instructions by a processor:
calculates a weighted load value for each of the access points by inputting the load data for each access point into a balancing algorithm, wherein the balancing algorithm includes the following variables:
a variance of a mean RSSI of the access point, the variance considering the mean RSSI both with and without the wireless client taken into account,
a quotient comparing the mean RSSI of the access point with the wireless client taken into account to the maximum possible RSSI for the access point, and
the FER of the access point;
compares the weighted load values of the access points to one another;
selects one access point from among the plurality of access points to accept the entry request from the wireless client according to a predetermined category, wherein the predetermined category is based on the comparison of the weighted load values;
instructs the selected access point to accept the entry request from the wireless client; and
instructs each of the non-selected access points to reject the entry request from the wireless client.