WIRELESS LAN NETWORK SYSTEM AND LOAD CONTROL METHOD

• US 20080031212A1
• Filed: 07/11/2007
• Published: 02/07/2008
• Est. Priority Date: 08/04/2006
• Status: Active Grant

• Current Assignee: NEC Corporation
• Original Assignee: NEC Corporation
• Inventors: OGURA, Daisuke
• Granted Patent: US 8,346,275 B2
• Time in Patent Office: Days
• US Class Current: 370/338
• CPC Class Codes: H04W 28/10 Flow control between communication endpoints
• CPC Class Codes: H04W 28/16 Central resource management; Negotiation of resources or communication parameters, e.g. negotiating bandwidth or QoS [Quality of Service]

Abstract

A plurality of access points enables communication between a higher network and a terminal, and also transmits a connection notice for notifying a connection with the terminal by establishing a wireless connection with the terminal within the coverage area. A policy control apparatus manages load state of each of the access points based on the connection notice transmitted from the access point, and instructs the over loaded access point to limit a connection with the terminal.

Claims

1. A wireless network system enabling communication between a terminal and a higher-level network by establishing a wireless connection with the terminal, said wireless network system comprising:

a plurality of access points which are previously connected with the higher-level network, and that form wireless coverage areas, when connecting with the terminal within the coverage area, enable communication between the higher-level network and the terminal, and also transmit a connection notice to notify that a connection with the terminal has been established; and

a policy control apparatus which is connected with the plurality of access points, manages load state of each of the access points based on the connection notice transmitted from the access point, and instructs the over loaded access point to limit a connect with the terminal.

2. The wireless network system according to claim 1, wherein the access point transmits the connection notice, that distinguishes a new call from an existing call, to the policy control apparatus, and

wherein the policy control apparatus previously sets a first threshold for limiting connection of the new call and a second threshold for limiting connection of the existing call, counts the number of terminals connected to each of the access points based on the connection notice, instructs the access point to limit connection of the new call when the number of terminals reaches the first threshold, and instructs the access point to limit connection of the existing call when the number of terminals reaches the second threshold.

3. The wireless network system according to claim 2,

wherein the first threshold is less than or equal to the second threshold.

4. The wireless network system according to claim 1, wherein when making a wireless connection with the terminal, the access point transmits the connection notice that distinguishes QoS classes to the policy control apparatus, and

wherein the policy control apparatus previously sets the weight of a call for each of the QoS classes, and manages the accumulated value of the load of each of the access points by accumulating the value weighted by the weight based on the connection notice.

5. The wireless network system according to claim 4,

wherein the policy control apparatus previously sets a plurality of thresholds for limiting connection of a call for each of the QoS classes, compares the accumulated value that is calculated based on the connection notice with the plurality of thresholds, and limits connection of a call for each of the QoS classes according to each comparison result.

6. The wireless network system according to claim 1, wherein when rejecting a connection request from the terminal according to an instruction from the policy control apparatus, the access point transmits a notice of connection rejection to the policy control apparatus, and

wherein when receiving the notice of connection rejection, if the access point which transmits the notice of connection rejection is in an over load state, and if a nearby access point whose coverage area overlaps with a coverage area of the access point not in an overload state, the policy control apparatus directs the terminal from the access point in an overload state to the access point not in an overload state.

7. The wireless network system according to claim 6, wherein the policy control apparatus directs the terminal of the access point in the overload state to the access point in the not overload state by causing the access point in the overload state to decrease transmission electric power and by causing the access point in the not overload state to increase the transmission electric power.

8. A policy control apparatus connected to an access point that forms a wireless LAN that enables communication between a terminal and a higher-level network by establishing a wireless connection with the terminal, said policy control apparatus comprising:

a control signal communicator which connects to the plurality of access points previously connected with the higher-level network, and communicates by control signal with each of the access points; and

a load balancer which receives a connection notice transmitted from the access point that enables communication between the terminal and the higher-level network by establishing a wireless connection with a terminal through the control signal communicator, manages load state of each of the access points based on the connection notice, and instructs the access point in an overload state to limit a connection with the terminal through the control signal communicator.

9. The policy control apparatus according to claim 8,

wherein the access point transmits the connection notice which distinguishes a new call from an existing call to the policy control apparatus, and

wherein the load balancer of the policy control apparatus previously sets a first threshold for limiting a connection of the new call and a second threshold for limiting a connection of the existing call, counts the number of terminals connected to each of the access points based on the connection notice, instructs the access point to limit a connection of the new call when the number of terminals reaches the first threshold, and instructs the access point to limit a connection of the existing call when the number of terminals reaches the second threshold.

10. The policy control apparatus according to claim 9,

wherein the first threshold is less than or equal to the second threshold.

11. The policy control apparatus according to claim 8,

wherein when establishing a wireless connection with the terminal, the access point transmits the connection notice that distinguishes QoS classes to the policy control apparatus, and

wherein the load balancer of the policy control apparatus previously sets the weight of a call for each of the QoS classes, and manages the accumulated value of the load of each of the access points by accumulating a value weighted by the weight based on the connection notice.

12. The policy control apparatus according to claim 11,

wherein the load balancer previously sets a plurality of thresholds for limiting a connection of a call for each of the QoS classes, compares the accumulated value calculated based on the connection notice with the plurality of thresholds, and limits a connection of a call for each of the QoS classes according to each comparison result.

13. The policy control apparatus according to claim 8,

wherein when rejecting a connection request from the terminal according to an instruction from the policy control apparatus, the access point transmits a notice of connection rejection to the policy control apparatus, and

wherein when receiving the notice of connection rejection, if the access point which transmits the notice of connection rejection is in an over load state, and if a nearby access point whose coverage area overlaps with a coverage area of the access point not in an overload state, the load balancer of the policy control apparatus directs the terminal of the access point in an overload state to the access point not in an overload state.

14. The policy control apparatus according to claim 13,

wherein the load balancer directs the terminal of the access point in the overload state to the access point in the not overload state by causing the access point in the overload state to decrease transmission electric power and by causing the access point in the not overload state to increase the transmission electric power.

15. An access point forming a wireless LAN network that enables communication between a terminal and a higher-level network by establishing a wireless connection with a terminal, and that is connected to a policy control apparatus managing the wireless LAN network, said access point comprising:

a control signal communicator which communicates by control signal with the policy control apparatus; and

a connection processor which enables communication between the higher-level network and the terminal, and also transmits a connection notice for notifying a connection with the terminal to the policy control apparatus through the control signal communicator if a wireless connection has been established between the connection processor and the terminal within a coverage area, and if the connection processor is instructed to limit a connection with the terminal from the policy control apparatus through the control signal communicator, rejects a connection request from the terminal according to the instruction.

16. A load control method for a wireless LAN network system including a plurality of access points enabling communication between a terminal and a higher-level network by establishing a wireless connection with the terminal and a policy control apparatus connected to the plurality of access points, comprising:

if the access point establishes a wireless connection with the terminal within the coverage area, enabling communication between the higher-level network and the terminal and also transmitting a connection notice for notifying a connection with the terminal to the policy control apparatus;

managing load state of each of the access points based on the connection notice received by the policy control apparatus from the access point; and

instructing the over loaded access point to limit a connection with the terminal.