Access point initiated forced roaming based upon bandwidth

• US 20040001467A1
• Filed: 06/26/2002
• Published: 01/01/2004
• Est. Priority Date: 06/26/2002
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Cromer, Daryl Carvis, Locker, Howard Jeffrey, Jakes, Philip John, Ward, James Peter
• Granted Patent: US 7,203,183 B2
• Time in Patent Office: Days
• US Class Current: 370/338
• CPC Class Codes: H04W 28/0835 Access entity, e.g. eNB
• CPC Class Codes: H04W 28/0861 between base stations
• CPC Class Codes: H04W 28/20 Negotiating bandwidth
• CPC Class Codes: H04W 84/12 WLAN [Wireless Local Area Networks]

Abstract

Apparatus and method provides dynamic load balancing of network bandwidth between access points in an 802.11 wireless LAN. The access point generates and monitors average bandwidth utilization of client devices connected to said access point. The average bandwidth utilization for each client device is aggregated and selected clients are forced to roam to other access points if the aggregate bandwidth is equal or exceeds a threshold.

Claims

1. A method to load balance traffic in a communications network including the acts of:

dynamically generating and maintaining, in an Access Point, a table which lists, among other things, average bandwidth used by each client device associated with said Access Point;

monitoring in said table bandwidth usage of each of the client devices; and

forcing at least one client to disconnect from said Access Point if aggregate bandwidth usage at said Access Point exceeds a predetermined threshold.

2. The method of claim 1 wherein the table further includes identification for each client device, IP address assigned to each client device and signal strength for each client device.

3. The method of claim 2 wherein the signal strength is normalized for each client device.

4. The method of claim 2 wherein the table further includes a flag which is activated if the predetermined threshold value is exceeded and sub-field in which aggregate bandwidth utilization is recorded.

5. The method of claim 1 wherein the monitoring act further includes summing the bandwidth utilization of the client devices to generate aggregate bandwidth usage.

6. The method of claim 5 further including the act of activating a Force Roam Flag if the aggregate bandwidth usage exceeds the predetermined threshold.

7. The method of claim 6 wherein the predetermined threshold is set to allow for extra capacity on the network to handle burst in client device activity.

8. The method of claim 1 wherein the forcing act further includes determining the at least one client to disconnect;

generating a Request to redistribute packet; and

forwarding the Request to redistribute packet to at least one Access Point.

9. The method of claim 8 wherein the Request to redistribute packet includes identity, IP address, signal strength and average bandwidth of the at least one client.

10. The method of claim 9 further including the acts of receiving a response packet to the Request to redistribute packet;

analyzing the response packet; and

informing the at least one client to force roam if the response packet indicates the at least one Access Point accepts the Request to redistribute.

11. The method of claim 1 further including the acts of receiving in said Access Point a Request to redistribute packet;

determining if said Access Point has excess capacity; and

accepting the request if said Access Point has excess capacity.

12. The method of claim 11 further including the acts of determining if client devices identified in the Request to Redistribute packet are within range of said Access Point;

and

determining if said Access Point can accept the client devices.

13. The method of claim 12 further including the acts of generating an accept response packet if both conditions are positive;

and

transmitting the accept response packet.

14. The method of claim 1 further including the acts of receiving in said Access Point a Request to Redistribute packet;

determining if said Access Point has excess capacity; and

denying the request if said Access Point does not have excess capacity.

15. A device including:

a controller;

a first adapter providing an interface to a wireless LAN;

a second adapter providing an interface to a wired LAN;

a first bus interconnecting the first adapter to the controller; and

a second bus interconnecting the controller to the second adapter, wherein said controller executing at least one program that forces a client device to roam if the bandwidth utilization in said device exceeds a predetermined threshold.

16. The device of claim 15 wherein the controller includes a programmable processor;

a memory operatively coupled to said processor;

a program storage containing firmware with instructions allowing the processor to execute programs to support the wired and wireless LANs; and

an interface flow controller coupling said processor to said first bus and said second bus.

17. The device of claim 16 wherein the memory further includes a table partitioned into a first sub-field in which identities of client devices communicating with said device are recorded, a second sub-field to record IP addresses of said client devices, a third sub-field to record signal strength information for said client devices, fourth sub-field to record average bandwidth utilization for each of the client devices, and fifth sub-field to record aggregate bandwidth utilization.

18. The device of claims 15 or 17 further including an indicia to indicate status of bandwidth utilization in said device.

19. The device of claim 15 wherein the first adapter includes an RF transducer;

a first FIFO operatively coupled to said RF transducer;

a second FIFO operatively coupled to said RF transducer; and

a controller operating in accordance with IEEE 802.11 b Wireless LAN specification operatively coupled to the TX FIFO and RX FIFO.

20. The device of claim 15 wherein the second adapter includes a physical layer coupling said second adapter to a wired LAN.

a TX FIFO operatively coupled to the physical layer;

an RX FIFO operatively coupled to the physical layer; and

a Medium Access Controller (MAC) operating in accordance with a protocol specification for wired LAN operatively coupled to the RX FIFO and TX FIFO.

21. The device of claim 20 wherein the protocol specification for wired LAN includes IEEE 802.3 ethernet specification.

22. A program product including:

a medium on which computer code is recorded, said computer code including

a first code set that monitors bandwidth utilization and activating a flag if bandwidth utilization exceeds a predetermined threshold;

a second code set that redistributes client devices if bandwidth utilization exceeds a predetermined threshold; and

a third code set that monitors Request to Redistribute message packets and issuing a conditional response.

23. The program product of claim 22 wherein the first code set further includes code for creating a table partitioned into sub-fields for writing each client'"'"'s device ID, IP address, Signal Strength and average bandwidth utilization;

code to calculate the average bandwidth utilization by each client device;

code for writing attributes in said sub-fields for each client'"'"'s devices;

code for aggregating the bandwidth of the client devices; and

code to compare the aggregate bandwidth with a threshold.

24. The program product of claim 22 wherein the second code set further includes

code to check status of redistribution flag;

code to determine which client device to redistribute;

code to create a Request to Redistribute packet; and

code to create a packet informing selected clients to force roam.

25. The program product of claim 22 wherein the third code set further includes

code to monitor for Request to Redistribute packets;

code to determine excess capacity; and

code to create a de-response.

26. The program product of claim 22 wherein the third code set further includes

code to monitor for Request to Redistribute packets;

and

code to determine excess capacity.

27. A method including acts of:

receiving in a client device a command informing said client device to force roam to a specified Access Point;

determining availability of specified Access Point; and

roaming to specified Access Point, if available.

28. A method including acts of:

receiving in a client device a command informing said client device to force roam to a specified Access Point; and

roaming to specified Access Point, if available.

29. A method to load balance traffic in a communications network including the acts of:

dynamically generating and maintaining, in an Access Point, a table which lists, among other things, average bandwidth used by each client device associated with said Access Point;

monitoring in said table bandwidth usage of each of the client devices; and

forcing at least one client to disconnect from said Access Point.

30. A device including:

a controller;

a first adapter providing an interface to a wireless LAN;

a second adapter providing an interface to a wired LAN;

a first bus interconnecting the first adapter to the controller; and

a second bus interconnecting the controller to the second adapter, wherein said controller executing at least one program that forces a client device to roam.

31. A device including:

an adapter providing an interface to a wireless LAN;

a storage having a table in which forced roam information is to be written dynamically, a processing subsystem including a processor that executes a program that scans the table and uses information therein to register with an Access Point; and

a bus-subsystem to couple the processing subsystem, the storage and the adapter.

32. The device of claim 31 further including a plurality of I/O devices operatively coupled to the bus subsystem.

33. The device of claim 31 wherein the bus subsystem includes a PCI Bus Controller and PCI bus extends operatively coupled to the PCI Bus Controller.