Access point to access point range extension

• US 7,664,075 B2
• Filed: 04/08/2005
• Issued: 02/16/2010
• Est. Priority Date: 02/28/2003
• Status: Expired due to Fees

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Shen, Hui, Abhishek, Abhishek, Ayyagari, Arun
• Primary Examiner(s): Cumming; William D
• Application Number:
  US11/102,612
• Publication Number:
  US 20050201347A1
• Time in Patent Office: 1,775 Days
• Field of Search: 455/415, 455/426, 455/411, 370/338, 370/328, 370/331
• US Class Current: 370/331
• CPC Class Codes: H04L 2101/622 Layer-2 addresses, e.g. medium access control [MAC] addresses
• CPC Class Codes: H04W 12/069 using certificates or pre-shared keys
• CPC Class Codes: H04W 48/16 Discovering, processing access restriction or access information
• CPC Class Codes: H04W 48/20 Selecting an access point
• CPC Class Codes: H04W 84/047 using dedicated repeater stations
• CPC Class Codes: H04W 84/12 WLAN [Wireless Local Area Networks]
• CPC Class Codes: H04W 92/20 between access points

Abstract

An architecture and methods for extending the depth of a WLAN to a four-level hierarchal access point structure including wireless access points. The wireless access points in the WLAN can be networked by scanning for a network, collecting one or more packets that identify the network from one or more access points, each packet including an address identifying an ancestry of the access points to an ancestral wired access point; and applying an access point selection algorithm to configure a parent access point. The architecture includes a scanning object configured to issue a scan request to a network interface and collect access point data; a selection object configured to filter and sort the collected access point data; an authentication state machine configured to perform authentication and validate; and an association state machine configured to compose a packet including hierarchical data indicative of access point ancestry to a conventional access point.

Claims

1. A wireless access point for forming a connection to a parent wireless access point as part of a bridge connection to a wired access point outside of the range of the wireless access point, the wired access point providing a connection to one or more wired networks, the wireless access point being adapted to form the connection to the parent wireless access point without forming a network ring, the wireless access point comprising:

a scanning object configured to issue a scan request to a network interface, the scanning object enabling collection of access point data from one or more potential parent access points;

a selection object configured to filter and sort the collected access point data to select a potential parent access point;

an authentication state machine configured to perform authentication and validate the potential parent access point; and

an association state machine configured to receive from the potential parent access point a packet including hierarchical data for the potential parent access point indicative of access point ancestry, the hierarchical data comprising a listing of the potential parent access point and at least one other wireless repeater access point to which the potential parent access point is connected, and compare the hierarchical data to identifying information on the wireless access point and/or zero or more child access points of the wireless access point to determine if the hierarchical data of the potential parent access point includes the wireless access point and/or one or more of the child access points.

2. The wireless access point of claim 1 further including a router module, the router module configured to accept data packets with up to four access point addresses therein and to determine a next forward hop for data packets destined outside a local cell area of the wireless access point.

3. The wireless access point of claim 2 wherein the router module includes a hash table configured to enable linking of one or more routing entries wherein an input to the hash table is one or more media access control (MAC) addresses.

4. The wireless access point of claim 2 wherein the router module includes a table reaper to remove out of date entries from a routing table and a routing entry refresher configured to determine whether a media access control (MAC) address is associated with a disconnected access point and to remove the MAC address from the routing table.

5. The wireless access point of claim 1 further including an access point reset routine object configured to instantiate when the wireless access point requires a reset for receiving a parent access point (PAP) beacon, the access point rest routine configured to stop any ongoing authentication or association as part of a wireless local area network (WLAN) protocol.

6. The wireless access point of claim 5 wherein the reset is performed when one or more of a PAP beacon being received with an unexpected session;

PAP beacon not being received for a predetermined period of time; and

when a repeater AP is disassociated from a PAP due to lack of activity beyond a predetermined amount of time.

7. The wireless access point of claim 1 wherein the packet includes an element for the hierarchical data, the element configured to identify up to four levels of access points.

8. The wireless access point of claim 7 wherein the wireless access point enables a hierarchical relationship among two or more wireless devices acting as access points.

9. The wireless access point of claim 7 wherein the authentication state machine exposes a plurality of application programming interfaces (APIs) for operating the authentication state machine.

10. The wireless access point of claim 9 wherein the authentication state machine exposes a SoftAPPAMAuthentication API to provide an entry point routine to initiate an authentication procedure.

11. The wireless access point of claim 9 wherein the authentication state machine exposes a SoftAPPAMCancelAuthentication API stop and cancel an ongoing authentication procedure.

12. The wireless access point of claim 9 wherein the authentication state machine exposes a SoftAPPAMReceiveAuth API to call one or more routines to process the packet based on an authentication algorithm, a packet sequence number and a state of the authentication state machine.

13. The wireless access point of claim 9 wherein the authentication state machine exposes a SoftAPPAMAuthCompletion API to cause a repeater AP to perform a post authentication operation and trigger an association process.

14. The wireless access point of claim 7 wherein the association state machine exposes one or more application programming interfaces for operating the association state machine.

15. The wireless access point of claim 14 wherein the association state machine exposes a SoftAPPAMAssocation API to provide an entry point routine for initiating an association procedure.

16. The wireless access point of claim 14 wherein the association state machine exposes a SoftAPPAMInternalAssocCompletion API to enable the access point to perform post association operations.

17. The wireless access point of claim 1, wherein the selection object is configured to select the potential parent access point as the parent access point based at least in part on the hierarchical data, such that the potential parent access point may be selected if the association state machine determines that there is no match between the hierarchical data and the identifying information.