Seamless mobility in wireless networks

• US 8,787,309 B1
• Filed: 10/27/2010
• Issued: 07/22/2014
• Est. Priority Date: 12/05/2005
• Status: Active Grant

• Current Assignee: Fortinet Inc.
• Original Assignee: Meru Networks, Inc. (Fortinet Inc.)
• Inventors: Bharghavan, Vaduvur, Han, Sung-Wook, Epstein, Joseph, Dunsbergen, Berend, Balasubramanian, Saravanan
• Primary Examiner(s): Eng, George
• Assistant Examiner(s): HAMMONDS, MARCUS C
• Application Number:
  US12/913,584
• Time in Patent Office: 1,364 Days
• Field of Search: 370/238, 370331-334, 370/338, 370/328, 455436-444
• US Class Current: 370/331
• CPC Class Codes: H04W 28/0226 based on location or mobility handoff or reselection H04W36/00; mobile application services making use of the location of users or terminals H04W4/02
• CPC Class Codes: H04W 28/086 among access entities
• CPC Class Codes: H04W 36/18 for allowing seamless reselection, e.g. soft reselection
• CPC Class Codes: H04W 60/00 Affiliation to network, e.g. registration; Terminating affiliation with the network, e.g. de-registration
• 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 8/26 Network addressing or numbering for mobility support
• CPC Class Codes: H04W 84/105 PBS [Private Base Station] network H04W84/12 - H04W84/16 take precedence

Abstract

AP'"'"'s associated with a communication network and any wireless devices desiring contact, operated according to a protocol in which each wireless device selects AP'"'"'s with which to communicate. A system coordinator causes the AP'"'"'s to operate so as to guide each wireless device to an AP selected by the system coordinator. This has the effect that, notwithstanding that the protocol involves having the wireless device make the selection of AP, functionally, the AP'"'"'s make the selection for it. In a 1^st technique, multiple AP'"'"'s share an identifier, with the system coordinator directing one particular AP to respond to the wireless device, thus appearing to wireless devices as a “personal cell”. In a 2^nd technique, AP'"'"'s each maintain identifiers substantially unique to each wireless device, with the system coordinator directing only one particular AP to maintain any particular wireless device'"'"'s identifier, thus appearing to wireless devices as a “personal AP”.

Claims

1. A computer-implemented method in a system coordinator to provide seamless mobility to an end point in a wireless network by controlling soft handoffs of the end point among access points with the use of a persistent, uniquely-assigned BSSID (Basic Service Set Identifier), comprising:

selecting at least one communication parameter to associate with a BSSID;

sending a beacon from a first access point to advertise its presence, wherein the beacon comprises the BSSID associated with the at least one communication parameter;

responsive to the mobile station choosing the BSSID being advertised in the beacon sent from the first access point, selecting to uniquely assign the BSSID to a mobile station;

associating the first access point from the plurality of access points with the mobile station, wherein associating comprises using the uniquely-assigned BSSID with the mobile station persistently and associating is made as selected by the system coordinator, the uniquely assigned BSSID being independent of an identify of mobile station and being eligible for subsequent assignment to a different mobile station as determined by the system coordinator;

determining that the mobile station should be handed-off from the first access point to a second access point among the plurality of access points;

handing-off the mobile station by changing associations of the uniquely-assigned BSSID from the first access point to a second access point, wherein a coordinator database of the system coordinator is updated according to the change, the coordinator database storing a plurality of access point identifiers in association with a plurality of mobile station identifiers, wherein the uniquely-assigned BSSID is persistent due to the mobile station maintaining the uniquely assigned BSSID through hand-offs between access points; and

responsive to the hand-off, seamlessly continuing communication with the mobile station at the second access point while using the same uniquely-assigned BSSID without change at the mobile station, such that the mobile station continues communication with the second access point as if communication was still occurring with the first access point.

2. The method of claim 1, wherein associating the mobile station comprises:

associating the mobile station with the first access point in a wireless network using the uniquely-assigned BSSID among a plurality of stored uniquely assigned BSSIDs assigned to a plurality of mobile devices.

3. The method of claim 1, wherein associating the mobile station comprises:

associating the mobile station with the first access point in a wireless network using the uniquely-assigned BSSID among a plurality of stored uniquely assigned BSSIDs assigned to a plurality of mobile devices, wherein the plurality of stored uniquely-assigned BSSIDs are stored at the first access point to facilitate communication between the first access point and the plurality of mobile devices.

4. The method of claim 1, wherein associating the mobile station comprises:

associating the mobile station with the first access point among the plurality of access points in the wireless network using the BSSID that is uniquely assigned to the mobile station, wherein the mobile station operates according to a protocol in which the mobile station natively selects access points with which to communicate.

5. The method of claim 1, wherein associating the mobile station further comprises:

associating the mobile station with the first access point, wherein the mobile station is within range of at least two access points of the plurality of access points.

6. The method of claim 1, wherein handing-off the mobile station comprises:

disassociating the mobile station by deleting the uniquely-assigned BSSID stored at the first access point in favor of associating the mobile station by storing the uniquely-assigned BSSID at the second access point.

7. The method of claim 1, wherein handing-off the mobile station comprises:

responsive to a change in location of the mobile device, handing-off the mobile station.

8. The method of claim 1, wherein handing-off the mobile station further comprises:

responsive to load optimization among components of the wireless network, from a global perspective of all mobile devices and all access points, handing-off the mobile station from the first access point to the second access point.

9. The method of claim 1, wherein handing-off the mobile station further comprises:

responsive to QoS (quality of service) requirements, handing-off the mobile station.

10. The method of claim 1, wherein handing-off the mobile station further comprises:

responsive to global state information concerning components in the wireless network, handing-off the mobile station.

11. The method of claim 1, further comprising:

sending the beacon from the first access point to advertise its presence, wherein the beacon comprises multiple BSSIDs.

12. The method of claim 1, wherein the at least one communication parameter comprises at least one of access control, a backoff or retry parameter, a channel selection parameter, quality of service, and transmit power.

13. The method of claim 1, wherein selecting the first access point from the plurality of access points comprises:

selecting the first access point from the plurality of access points based on characteristics of communication by the mobile station.

14. The method of claim 1, wherein determining that the mobile station should be handed-off from the first access point to the second access point among the plurality of access points:

determining that the mobile station should be handed-off from the first access point to the second access point among the plurality of access points to change an interference pattern of the plurality of access points for optimizing aggregate utilization of a shared spectrum.

15. The method of claim 1, further comprises the uniquely-assigned BSSID from a plurality of persistent, uniquely-assigned BSSIDs to associate with the mobile station based on one or more communication parameters of the uniquely-assigned BSSID selected from the group of:

access control parameters, backoff or retry parameters, channel selection parameters, QoS parameters, and transmit power parameters.

16. A computer-implemented method, comprising:

selecting at least one communication parameter to associate with a BSSID (Basic Service Set Identifier);

sending a beacon from an access point to advertise its presence, wherein the beacon comprises the BSSID associated with the at least one communication parameter;

uniquely assigning the BSSID to a mobile station, the BSSID being advertised in the beacon and being independent of an identity of the mobile station for subsequent assignment of a different mobile station;

associating a mobile station with a first access point among a plurality of access points in a wireless network for communication using the uniquely assigned BBSID

handing-off the mobile station by changing associations from the first access point to a second access point among the plurality of access points;

responsive to the hand-off, seamlessly continuing communication with the mobile station at the second access point while using the same uniquely-assigned BBSID without change at the mobile station;

changing at least one communication parameter to associate with the mobile station; and

forcing the mobile station to select a different BSSID associated with the changed communication parameter.

17. A computer implemented method, comprising:

selecting at least one communication parameter to associate with a BSSID;

sending a beacon from a first access point to advertise its presence, wherein the beacon comprises the BSSID associated with the at least one communication parameter;

uniquely assigning the BSSID (Basic Service Set Identifier) to a mobile station, the BSSID being advertised in the beacon and being independent of an identity of the mobile station for subsequent assignment of a different mobile station, wherein the uniquely assigned BSSID is unique to the extent that no range overlap exists between access points from a plurality of access points which use the same uniquely-assigned BSSID;

associating the mobile station with the first access point among the plurality of access points in a wireless network for communication using the uniquely-assigned BSSID;

handing-off the mobile station by changing associations from the first access point to a second access point among the plurality of access points;

responsive to the hand-off, seamlessly continuing communication with the mobile station at the second access point while using the same uniquely-assigned BSSID without change at the mobile station;

responsive to conflict between mobile devices using the same uniquely-assigned BSSID, reassigning at least one of the mobile devices to an updated uniquely-assigned BSSID.

18. At least one non-transitory computer readable medium storing a computer program product that when executed by a processor performs a method in a system coordinator to provide seamless mobility to an end point in a wireless network by controlling soft handoffs of the end point among access points with the use of a persistent, uniquely-assigned BSSID (Basic Service Set Identifier), comprising:

selecting at least one communication parameter to associate with a BSSID;

sending a beacon from a first access point to advertise its presence, wherein the beacon comprises the BSSID associated with the at least one communication parameter;

responsive to the mobile station choosing the BSSID being advertised in the beacon sent from the first access point, selecting to uniquely assign the BSSID to a mobile station;

associating the first access point from the plurality of access points with the mobile station, wherein associating comprises using the uniquely-assigned BSSID with the mobile station persistently and associating is made as selected by the system coordinator, the uniquely assigned BSSID being independent of an identify of mobile station and being eligible for subsequent assignment to a different mobile station as determined by the system coordinator;

determining that the mobile station should be handed-off from the first access point to a second access point among the plurality of access points;

handing-off the mobile station by changing associations of the uniquely-assigned BSSID from the first access point to a second access point, wherein a coordinator database of the system coordinator is updated according to the change, the coordinator database storing a plurality of access point identifiers in association with a plurality of mobile station identifiers, wherein the uniquely-assigned BSSID is persistent due to the mobile station maintaining the uniquely assigned BSSID through hand-offs between access points; and

responsive to the hand-off, seamlessly continuing communication with the mobile station at the second access point while using the same uniquely-assigned BSSID without change at the mobile station, such that the mobile station continues communication with the second access point as if communication was still occurring with the first access point.

19. A system coordinator to provide seamless mobility to an end point in a wireless network by controlling soft handoffs of the end point among access points with the use of a persistent, uniquely-assigned BSSID (Basic Service Set Identifier), comprising:

a first module to select at least one communication parameter to associate with a BSSID;

a second module to send a beacon from a first access point to advertise its presence, wherein the beacon comprises the BSSID associated with the at least one communication parameter;

a third module to responsive to the mobile station choosing the BSSID being advertised in the beacon sent from the first access point, select to uniquely assign the BSSID to a mobile station;

a fourth module to associate the first access point from the plurality of access points with the mobile station, wherein associating comprises using the uniquely-assigned BSSID with the mobile station persistently and associating is made as selected by the system coordinator, the uniquely assigned BSSID being independent of an identify of mobile station and being eligible for subsequent assignment to a different mobile station as determined by the system coordinator;

a fifth module to determine that the mobile station should be handed-off from the first access point to a second access point among the plurality of access points;

a sixth module to hand-off the mobile station by changing associations of the uniquely-assigned BSSID from the first access point to a second access point, wherein a coordinator database of the system coordinator is updated according to the change, the coordinator database storing a plurality of access point identifiers in association with a plurality of mobile station identifiers, wherein the uniquely-assigned BSSID is persistent due to the mobile station maintaining the uniquely assigned BSSID through hand-offs between access points; and

a seventh module to responsive to the hand-off, seamlessly continue communication with the mobile station at the second access point while using the same uniquely-assigned BSSID without change at the mobile station, such that the mobile station continues communication with the second access point as if communication was still occurring with the first access point.