Network-based control of stations in a wireless communication network

• US 9,215,745 B1
• Filed: 02/22/2008
• Issued: 12/15/2015
• Est. Priority Date: 12/09/2005
• Status: Active Grant

• Current Assignee: Fortinet Inc.
• Original Assignee: Meru Networks, Inc. (Fortinet Inc.)
• Inventors: Dunsbergen, Berend, Poomagame, Anand P.
• Primary Examiner(s): Addy, Anthony
• Assistant Examiner(s): Hammonds, Marcus
• Application Number:
  US12/035,925
• Time in Patent Office: 2,853 Days
• Field of Search: 370/328, 370/338, 370/331
• US Class Current: 1/1
• CPC Class Codes: H04L 1/1835 Buffer management
• CPC Class Codes: H04L 1/1874 Buffer management
• CPC Class Codes: H04L 1/188 Time-out mechanisms
• CPC Class Codes: H04W 24/02 Arrangements for optimising operational condition
• CPC Class Codes: H04W 36/38 by fixed network equipment
• CPC Class Codes: H04W 84/12 WLAN [Wireless Local Area Networks]

Abstract

Using the feature named “KEY_SEARCH_AD1” in the Atheros 11n chipset, an access point can determine whether to send an ACK packet in response to a message packet in response to whether the BSSID present in the sender address is present in the keycache. The AP can maintain a list of about 128 arbitrarily selected BSSID'"'"'s, to each of which it will respond with an ACK packet if it receives a message from a mobile station with that BSSID. (1) the number of mobile stations that can be assigned to that AP is relatively greater. (2) the selection of those BSSID'"'"'s is no longer constrained by having to match the AP'"'"'s BSSID using a mask. With selection of those BSSID'"'"'s being no longer so constrained, it is easier to assign BSSID'"'"'s to mobile stations while allowing those mobile stations to roam among multiple AP'"'"'s.

Claims

1. A computer-implemented method in an access point of a plurality of access points managed by a controller of a wireless communication network, the method for utilizing BSSIDs (basic service set identifiers) to maintain individual control of stations that communicate using a protocol inherent to the stations, the method comprising the steps of:

storing, in the access point, a BSSID assigned to the access point by the controller;

storing, in the access point, a plurality of persistent, uniquely-assigned BSSIDs, each persistent, uniquely-assigned BSSID being individually assigned to each station by the controller responsive to stations assigned to the access point for servicing, wherein uniqueness of the BSSID allows the controller to individually manage stations, and wherein persistence of the BSSID allows the controller to maintain individual control over each station after moving to a second access point of the plurality of access points from the access point, wherein each persistent, uniquely-assigned BSSID is stored at both a station and the access point, each of the plurality of access points independently using layer 2 communications, and each persistent, uniquely-assigned BSSID configured in the station by the access point with a beacon frame or a probe response frame sent from the access point to the mobile station;

receiving a message frame from a station, the modified message frame comprising a receiver address defined by the persistent, uniquely-assigned BSSID and a sender address defined by a MAC address unique to the station;

determining whether to send an ACK frame to the station, the ACK frame comprising a receiver address defined by the unique MAC address of the mobile station and a sender address defined by the persistent, uniquely-assigned BSSID of the station, the determination comprising comparing the receiver address of the received modified message frame to one of the stored plurality of persistent, uniquely assigned BSSIDs; and

responsive to matching the receiver address of the received modified message frame to one of the stored plurality of persistent, uniquely-assigned BSSIDs, generating the ACK frame indicative of a successful transmission.

2. The method of claim 1, further comprising:

enabling a key search bit, wherein matching the persistent, uniquely-assigned BSSID to one of the stored plurality of persistent, uniquely assigned BSSIDs is responsive to the enabled key search bit.

3. The method of claim 1, further comprising:

disabling a key search bit; and

responsive the disabled key search bit, matching the receiver address of the received modified message frame to the plurality of persistent, uniquely-assigned BSSIDs.

4. The method of claim 1, further comprising:

disabling a key search bit;

responsive the disabled key search bit, sending an unmodified message frame to the station rather than a modified message frame, the unmodified message frame comprising the sender address defined by the persistent, uniquely-assigned BSSID and the receiver address defined by the mobile station MAC address; and

responsive the disabled key search bit, matching the sender address of the received ACK frame to the plurality of persistent, uniquely-assigned BSSIDs.

5. The method of claim 1, wherein storing the plurality of BSSIDs comprises:

storing the plurality of persistent, uniquely-assigned BSSIDs in a key cache integrated within a processor of the access point.

6. The method of claim 5, wherein the key cache comprises a plurality of registers, each register storing one of the plurality of persistent, uniquely-assigned BSSIDs.

7. The method of claim 1, wherein the persistent, uniquely-assigned BSSID cannot be identified by masking one of the plurality of persistent, uniquely-assigned BSSIDs.

8. The method of claim 1, further comprising:

storing the persistent, uniquely-assigned BSSID based on the controller assigning the station to the access point among a plurality of access points being controlled.

9. The method of claim 1, further comprising:

deleting the persistent, uniquely-assigned BSSID based on a controller de-assigning the station to the access point among a plurality of access points being controlled.

10. A non-transitory computer readable medium storing a computer program product to perform a method in an access point of a plurality of access points managed by a controller of a wireless communication network, the method for utilizing BSSIDs (basic service set identifiers) to maintain individual control of stations that communicate using a protocol inherent to the stations, the method comprising the steps of:

storing, in the access point, a BSSID assigned to the access point by the controller;

storing, in the access point, a plurality of persistent, uniquely-assigned BSSIDs, each persistent, uniquely-assigned BSSID being individually assigned to each station by the controller responsive to stations assigned to the access point for servicing, wherein uniqueness of the BSSID allows the controller to individually manage stations, and wherein persistence of the BSSID allows the controller to maintain individual control over each station after moving to a second access point of the plurality of access points from the access point, wherein each persistent, uniquely-assigned BSSID is stored at both a station and the access point, each of the plurality of access points independently using layer 2 communications, and each persistent, uniquely-assigned BSSID configured in the station by the access point with a beacon frame or a probe response frame sent from the access point to the mobile station;

receiving a message frame from a station, the modified message frame comprising a receiver address defined by the persistent, uniquely-assigned BSSID and a sender address defined by a MAC address unique to the station;

determining whether to send an ACK frame to the station, the ACK frame comprising a receiver address defined by the unique MAC address of the mobile station and a sender address defined by the persistent, uniquely-assigned BSSID of the station, the determination comprising comparing the receiver address of the received modified message frame to one of the stored plurality of persistent, uniquely assigned BSSIDs; and

responsive to matching the receiver address of the received modified message frame to one of the stored plurality of persistent, uniquely-assigned BSSIDs, generating the ACK frame indicative of a successful transmission.

11. An access point of a system including a plurality of access points managed by a controller of a wireless communication network, the system to utilize BSSIDs (basic service set identifiers) to maintain individual control of stations that communicate using a protocol inherent to the stations, the access point comprising:

a register to store a BSSID assigned to the access point by the controller, the register to internally store a plurality of persistent, unique-assigned BSSIDs, each uniquely-assigned BSSID being individually assigned to each station by the controller responsive to stations assigned to the access point for servicing, wherein uniqueness of the BSSID allows the controller to individually manage stations, and wherein persistence of the BSSID allows the controller to maintain individual control over each station after moving to a second access point of the plurality of access points from the access point, wherein each persistent, uniquely-assigned BSSID is stored at both a station and the access point, each of the plurality of access points independently using layer 2 communications, and each persistent, uniquely-assigned BSSID configured in the station by the access point with a beacon frame or a probe response frame sent from the access point to the mobile station; and

an interface, coupled in communication with the register and the processor, to receive a modified message frame from a station, the modified message frame comprising a receiver address defined by the persistent, uniquely-assigned BSSID and a sender address defined by a MAC address unique to the station;

a processor to determine whether to send an ACK frame to the station, the ACK frame comprising a receiver address defined by the unique MAC address of the mobile station and a sender address defined by the persistent, uniquely-assigned BSSID of the station, the determination comprising comparing the receiver address of the received modified message frame to one of the stored plurality of persistent, uniquely assigned BSSIDs and responsive to matching the receiver address of the received modified message frame to one of the stored plurality of persistent, uniquely-assigned BSSIDs, generating the ACK frame indicative of a successful transmission.