Method and apparatus for smooth disassociation of stations from access points in an 802.11 WLAN

• US 7,633,910 B2
• Filed: 04/22/2004
• Issued: 12/15/2009
• Est. Priority Date: 04/30/2003
• Status: Expired due to Fees

• Current Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Original Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Inventors: Zhun, Zhong, Mangold, Stefan, Soomro, Amjad
• Primary Examiner(s): Le; Danh C
• Application Number:
  US10/555,051
• Publication Number:
  US 20060227731A1
• Time in Patent Office: 2,063 Days
• Field of Search: 370/328, 370/338, 370/331, 370/310, 455/434, 455/433, 455/418
• US Class Current: 370/338
• CPC Class Codes: H04W 36/08 Reselecting an access point
• CPC Class Codes: H04W 36/18 for allowing seamless reselection, e.g. soft reselection
• CPC Class Codes: H04W 36/22 for handling the traffic
• CPC Class Codes: H04W 60/06 De-registration or detaching
• CPC Class Codes: H04W 76/34 Selective release of ongoing connections
• CPC Class Codes: H04W 84/12 WLAN [Wireless Local Area Networks]
• CPC Class Codes: H04W 88/08 Access point devices

Abstract

A plurality of methods, apparatus and computer program for providing warning to a station (STA) associated with an Access Point (AP) in a WLAN that a disassociation the AP is imminent. The steps include (a) selecting a station (STA) for disassociation from a particular Access Point (AP) of a WLAN; (b) by updating a newly created reason code field of a message to indicate to the selected STA that it has become a candidate for disassociation; and (c) transmitting the message to the selected STA. Upon receipt by the STA of a message indicating that the selected STA has become a candidate for disassociation, the selected station scans other Access Points from a list to find another Access Point to associate with before being cut off by the current Access Point.

Claims

1. A method of providing a warning that a disassociation from an Access Point of a Wireless Local Area Network (WLAN) is imminent, comprising:

selecting a station for the disassociation from the Access Point of the WLAN;

updating a reason code field of one of one of (i) a measurement report message; and

(ii) a site report response message to indicate the selected station that has become a candidate for disassociation; and

transmitting the message with the updated reason code field to the selected station, wherein the message is updated by including a numerical value in the reason code field that identifies the station as a disassociation candidate, and wherein the value is selected from a plurality of possible values, each value corresponding to a particular reason for notifying the station.

2. The method according to claim 1, further comprising identifying in an activation delay field of the message an indication of a time period in which the disassociation will occur.

3. The method according to claim 1, wherein the station scans at least one Access Point other than said Access Point to associate with.

4. The method according to claim 1, wherein the station scans all of the Access Points in a list provided to the station.

5. The method according to claim 1, wherein the WLAN includes an IEEE 802.11 local area network.

6. The method according to claim 1, further comprising:

sending a Disassociation Action Frame to the station to end communication with said Access Point.

7. A computer program, embedded in a computer readable medium, for providing a warning that a disassociation from an Access Point of a Wireless Local Area Network (WLAN) is imminent, comprising:

selecting a station for the disassociation from the Access Point of the WLAN;

updating a reason code field of one of(i) a measurement report message; and

(ii) a site report response message to indicate the selected station that has become a candidate for the disassociation; and

transmitting the message with the updated reason code field to the selected station, wherein the message is updated by including a numerical value in the reason code field that identifies the station as a disassociation candidate, and wherein the value is selected from a plurality of possible values, each value corresponding to a particular reason for notifying the station.

8. The computer program according to claim 7, further comprising:

sending a Disassociation Action Frame to the selected station after a predetermined period of time.

9. A system for providing a disassociation warning in a Wireless Local Area Network (WLAN), comprising:

a station for disassociating in the WLAN; and

an Access Point for updating a reason code field of one of (i) a measurement report message; and

(ii) a site report response message that indicates the station that is a candidate for disassociation, said Access Point transmitting the message with the updated reason code field to the station, wherein the message is updated by including a numerical value in the reason code field that identifies the station as a disassociation candidate, and wherein the value is selected from a plurality of possible values, each value corresponding to a particular reason for notifying the station.