Distributed seamless roaming in wireless networks

Patent metadata

Field	Value
Publication number	US-2016119827-A1
Application number	US-201614987688-A
Country	US
Kind code	A1
Filing date	Jan 4, 2016
Priority date	Oct 19, 2012
Publication date	Apr 28, 2016
Grant date	—

Abstract

One embodiment of the present invention provides a system for configuring an access point in a wireless network. During operation, the access point discovers one or more existing access points associated with the wireless network. The access point then obtains a set of configuration information from one existing access point, and synchronizes a local timestamp counter to a selected existing access point, thereby allowing the access point to be configured without using a centralized management station.

First claim

What is claimed is:

1 . A method for conducting a maintenance procedure at an access point without disrupting access to a wireless network, comprising:
responsive to a local access point of the wireless network detecting a maintenance condition for performing a maintenance procedure, handing over one or more user stations associated with the local access point to other access points of the wireless network; performing the maintenance procedure; responsive to the local access point completing the maintenance procedure, obtaining a set of configuration information from an existing access point that belongs to the wireless network; and in response to determining that the local access point has the best signal strength of a user station, allowing the user station to be associated with the local access point.

2 . The method of claim 1 , wherein performing the maintenance procedure involves conducting a spectrum scan to select a best available frequency.

3 . The method of claim 1 , wherein performing the maintenance procedure involves upgrading a firmware of the local access point.

4 . The method of claim 1 , further comprising:
multicasting a station query message to the other access points, wherein the station query message includes at least a media access control (MAC) address for the user station; and receiving signal strength values for the user station from the other access points.

5 . The method of claim 1 , wherein allowing the user station to be associated with the local access point involves:
comparing the local access point's signal strength value for the user station to signal strength values for the user station from the other access points; and determining that the local access point's signal strength value is the highest signal strength for the user station.

6 . The method of claim 1 , wherein handing over a user station to a remote access point involves:
flushing out any remaining packets for the user station in a local buffer; and responsive to determining that the local buffer does not include a packet for the user station, removing the user station from an associated station list for the local access point.

7 . The method of claim 1 , wherein handing over a user station to a remote access point involves:
sending a handover request message to the remote access point; and in response to receiving a switch request message from the remote access point, sending to the remote access point a switch response message that includes at least an association identifier for the user station.

8 . The method of claim 7 , wherein the switch response message also includes one or more of:
one or more 802.11 association information elements; station information; and 802.11 block-ACK and aggregation states for one or more traffic identifiers (TIDs).

9 . A wireless access point, comprising a processor and a memory coupled to the processor and storing instructions which when executed by the processor cause the processor to perform a method for conducting a maintenance procedure at the wireless access point without disrupting access to a wireless network, the method comprising:
responsive to the local wireless access point detecting a maintenance condition for performing a maintenance procedure, handing over one or more user stations associated with the local access point to other access points of the wireless network; performing the maintenance procedure; responsive to the local wireless access point completing the maintenance procedure, obtaining a set of configuration information from an existing access point that belongs to the wireless network; and in response to determining that the local wireless access point has the best signal strength of a user station, allowing the user station to be associated with the local wireless access point.

10 . The wireless access point of claim 9 , wherein performing the maintenance procedure involves conducting a spectrum scan to select a best available frequency.

11 . The wireless access point of claim 9 , wherein performing the maintenance procedure involves upgrading a firmware of the local wireless access point.

12 . The wireless access point of claim 9 , further comprising:
multicasting a station query message to the other access points, wherein the station query message includes at least a media access control (MAC) address for the user station; and receiving signal strength values for the user station from the other access points.

13 . The wireless access point of claim 9 , wherein allowing the user station to be associated with the local wireless access point involves:
comparing the local wireless access point's signal strength value for the user station to signal strength values for the user station from the other access points; and determining that the local wireless access point's signal strength value is the highest signal strength for the user station.

14 . The wireless access point of claim 9 , wherein handing over a user station to a remote access point involves:
flushing out any remaining packets for the user station in a local buffer; and responsive to determining that the local buffer does not include a packet for the user station, removing the user station from an associated station list for the local wireless access point.

15 . The wireless access point of claim 9 , wherein handing over a user station to a remote access point involves:
sending a handover request message to the remote access point; and in response to receiving a switch request message from the remote access point, sending to the remote access point a switch response message that includes at least an association identifier for the user station.

16 . The wireless access point of claim 15 , wherein the switch response message also includes one or more of:
one or more 802.11 association information elements; station information; and 802.11 block-ACK and aggregation states for one or more traffic identifiers (TIDs).

17 . A method for conducting a maintenance procedure at an access point without disrupting access to a wireless network, comprising:
responsive to a local access point of the wireless network detecting a maintenance condition for performing a spectrum scan, handing over one or more user stations associated with the local access point to other access points of the wireless network; performing the spectrum scan to select a best available frequency for the local access point; responsive to the local access point completing the spectrum scan, obtaining configuration information from an existing access point that belongs to the wireless network; and in response to determining that the local access point has the best signal strength of a user station, allowing the user station to be associated with the local access point.

18 . A wireless access point, comprising a processor and a memory coupled to the processor and storing instructions which when executed by the processor cause the processor to perform a method for conducting a maintenance procedure at the wireless access point without disrupting access to a wireless network, the method comprising:
responsive to the local wireless access point detecting a maintenance condition for performing a firmware upgrade procedure, handing over one or more user stations associated with the local access point to other access points of the wireless network; performing the firmware upgrade procedure to upgrade a firmware of the local wireless access point; responsive to the local wireless access point completing the f

Assignees

• Ubiquiti Networks Inc

Inventors

• Dayanandan Sriram
• Yang Bo-Chieh
• Lee Yuan-Hsiang
• Luoh Keh-Ming
• Pera Robert J

Classifications

• H04W72/542

  using measured or perceived quality · CPC title

• H04W8/02

  Processing of mobility data, e.g. registration information at HLR [Home Location Register] or VLR [Visitor Location Register]; Transfer of mobility data, e.g. between HLR, VLR or external networks · CPC title

• H04W84/18

  Self-organising networks, e.g. ad-hoc networks or sensor networks · CPC title

• H04W4/06 Primary

  Selective distribution of broadcast services, e.g. multimedia broadcast multicast service [MBMS]; Services to user groups; One-way selective calling services · CPC title

• H04W48/16

  Discovering, processing access restriction or access information · CPC title