Access point initiated forced roaming based upon bandwidth

• US 7,203,183 B2
• Filed: 06/26/2002
• Issued: 04/10/2007
• Est. Priority Date: 06/26/2002
• Status: Expired due to Fees

• 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
• Primary Examiner(s): Sam; Phirin
• Application Number:
  US10/180,768
• Publication Number:
  US 20040001467A1
• Time in Patent Office: 1,749 Days
• Field of Search: None
• 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, identification for each client device, IP address assigned to each client device, signal strength for each client device, a sub-field in which aggregate bandwidth usage is recorded, and a flag which is activated if aggregate bandwidth usage at said Access Point exceeds a predetermined threshold;

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 the predetermined threshold.

2. The method of claim 1 wherein the signal strength is normalized for each client device.

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

4. The method of claim 3 further including the act of activating a Force Roam Flag if the aggregate bandwidth usage exceeds the predetermined threshold.

5. The method of claim 4 wherein the predetermined threshold is set to allow for extra capacity on the network to handle bursts in client device activity.

6. 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.

7. The method of claim 6 wherein the Request to redistribute packet includes identity, IP address, signal strength and average bandwidth usage of the at least one client.

8. The method of claim 7 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.

9. 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.

10. The method of claim 9 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.

11. The method of claim 10 further including the acts of generating an accept response packet if both conditions are positive;

and transmitting the accept response packet.

12. 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.

13. A device including:

a controller comprising 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 wired and wireless LANs, and an interface flow controller coupling said processor to first bus and a second bus;

said memory comprising 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, a fourth sub-field to record average bandwidth utilization for each of the client devices, and fifth sub-field to record aggregate bandwidth utilization;

a first adapter providing an interface to a wireless LAN; and

a second adapter providing an interface to a wired LAN;

wherein the first bus interconnects the first adapter to the controller; and

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

14. The device of claim 13 further including an indicia to indicate status of bandwidth utilization in said device.

15. The device of claim 13 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 802.11b Wireless LAN specification operatively coupled to the TX FIFO and RX FIFO.

16. The device of claim 13 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 couple to the physical layer; and

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

17. The device of claim 16 wherein the protocol specification for a wired LAN includes the IEEE 802.3 ethernet specification.