Distributed seamless roaming in wireless networks

• US 10,165,477 B2
• Filed: 07/07/2017
• Issued: 12/25/2018
• Est. Priority Date: 10/19/2012
• Status: Active Grant

• Current Assignee: Ubiquiti Inc.
• Original Assignee: Ubiquiti Networks, Inc. (Ubiquiti Inc.)
• Inventors: Dayanandan, Sriram, Yang, Bo-chieh, Lee, Yuan-Hsiang, Luoh, Keh-Ming, Pera, Robert J.
• Primary Examiner(s): Pezzlo, John
• Application Number:
  US15/644,415
• Publication Number:
  US 20180146400A1
• Time in Patent Office: 536 Days
• Field of Search: 370252, 370329, 370331, 370462
• CPC Class Codes: H04L 5/0055 Physical resource allocation for ACK/NACK for physical mapping arrangements in ARQ protocols H04L1/1861
• CPC Class Codes: H04W 36/0044 of quality context information
• CPC Class Codes: H04W 36/0094 Definition of hand-off measurement parameters
• CPC Class Codes: H04W 36/18 for allowing seamless reselection, e.g. soft reselection
• CPC Class Codes: H04W 36/304 due to measured or perceived resources with higher communication quality
• CPC Class Codes: H04W 4/06 Selective distribution of broadcast services, e.g. multimedia broadcast multicast service [MBMS]; Services to user groups; One-way selective calling services
• CPC Class Codes: H04W 48/16 Discovering, processing access restriction or access information
• CPC Class Codes: H04W 72/542 using measured or perceived quality
• CPC Class Codes: H04W 8/02 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 Class Codes: H04W 84/12 WLAN [Wireless Local Area Networks]
• CPC Class Codes: H04W 84/18 Self-organising networks, e.g. ad-hoc networks or sensor networks
• CPC Class Codes: H04W 88/08 Access point devices

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.

Claims

1. A method for receiving handover of a user station in a wireless network, comprising:

receiving, by a local access point from a remote access point, a query message including at least a media access control (MAC) address for the user station;

determining a signal strength value of the user station based on a list of user stations with corresponding signal strength values;

sending, by the local access point to the remote access point, a query response message indicating the signal strength value;

receiving information associated with the user station from the remote access point; and

adding the user station to a list of stations associated with the local access point.

2. The method of claim 1, further comprising:

receiving, from the remote access point, a switch response message including at least an association ID (AID) for the user station.

3. The method of claim 2, 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).

4. The method of claim 1, further comprising:

sending a packet to a layer-2 switch with the MAC address of the user station as a source MAC address of the packet, thereby allowing the layer-2 switch to update a MAC forwarding table.

5. The method of claim 1, wherein the local access point has a signal strength for the user station that is higher than that of the remote access point and other access points of the wireless network.

6. The method of claim 1, further comprising:

receiving, from the remote access point, a handover request message;

sending, to the remote access point, a switch request message.

7. 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 receiving handover of a user station in a wireless network, the method comprising:

receiving, by a local access point from a remote access point, a query message including at least a media access control (MAC) address for the user station;

determining a signal strength value of the user station based on a list of user stations with corresponding signal strength values;

sending, by the local access point to the remote access point, a query response message indicating the signal strength value;

receiving information associated with the user station from the remote access point; and

adding the user station to a list of stations associated with the local access point.

8. The wireless access point of claim 7, wherein the method further comprises:

receiving, from the remote access point, a switch response message including at least an association ID (AID) for the user station.

9. The wireless access point of claim 8, 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).

10. The wireless access point of claim 7, wherein the method further comprises:

sending a packet to a layer-2 switch with the MAC address of the user station as a source MAC address of the packet, thereby allowing the layer-2 switch to update a MAC forwarding table.

11. The wireless access point of claim 7, wherein the local access point has a signal strength for the user station that is higher than that of the remote access point and other access points of the wireless network.

12. The wireless access point of claim 7, wherein the method further comprises:

receiving, from the remote access point, a handover request message;

sending, to the remote access point, a switch request message.

13. A computing system, comprising:

a processor; and

a storage device storing instructions which when executed by the processor cause the processor to perform a method, the method comprising;

receiving, by a local access point from a remote access point, a query message including at least a media access control (MAC) address for the user station;

determining a signal strength value of the user station based on a list of user stations with corresponding signal strength values;

sending, by the local access point to the remote access point, a query response message indicating the signal strength value;

receiving information associated with the user station from the remote access point; and

adding the user station to a list of stations associated with the local access point.

14. The computing system of claim 13, wherein the method further comprises:

receiving, from the remote access point, a switch response message including at least an association ID (AID) for the user station.

15. The computing system of claim 14, 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).

16. The computing system of claim 13, wherein the method further comprises:

sending a packet to a layer-2 switch with the MAC address of the user station as a source MAC address of the packet, thereby allowing the layer-2 switch to update a MAC forwarding table.

17. The computing system of claim 13, wherein the local access point has a signal strength for the user station that is higher than that of the remote access point and other access points of the wireless network.

18. The computing system of claim 13, wherein the method further comprises:

receiving, from the remote access point, a handover request message;

sending, to the remote access point, a switch request message.