Method and apparatus for extending a mobile unit data path between access points
View Patent ↗Fast transitions between access points (APs) in a wireless network may be accomplished when a mobile unit (MU) moves between the APs, by causing a first tunnel to be established between the APs, and causing a second tunnel to be established between the new AP and the MU. A data path having established security and quality of service parameters between the MU and the old AP may be extended through the tunnels, so that communication with the MU is not disrupted while transitioning between APs. Transition processing thus may be decoupled from movement of the MU, so that the MU may continue to receive access to data over the data path. Optionally, once the data path has been so extended, the MU and new AP may engage in authentication and other messaging to formally affect a handover of the data path to the new AP. The APs and MU may be configured to communicate according to the 802.11 protocol.
1. A method of enabling a data path between a first access point in a wireless network and a mobile unit to be extended to pass through a second access point in the same wireless network during a handoff process within the wireless network between the first and second access points, such that the data path extends from the first access point, to the second access point, and then to the mobile unit during the handoff process between base stations within the same wireless network, the method comprising the steps of:
receiving, by the first access point in the wireless network, a request from the second access point in the same wireless network to extend the data path between the first access point and the mobile unit over a tunnel from the first access point to the second access point so that data may be tunneled from the first access point to the second access point and provided by the second access point to the mobile unit during the handoff process between the first and second access points within the same wireless network before completion of the handoff process; and
transmitting data intended for the data path over the tunnel to the second access point for transmission by the second access point to the mobile unit prior to completion of the handoff process between the first and second access points in the wireless network.
2. The method of claim 1 , wherein the first access point has a first Media Access Control (MAC) associated with the data path, said MAC having established parameters for the data path.
3. The method of claim 2 , wherein the parameters include at least security and quality of service parameters.
4. The method of claim 2 , wherein the step of transmitting data intended for the data path comprises looping the data through the MAC associated with the data path.
5. The method of claim 2 , wherein the first access point has a second MAC associated with an interface to a source and a third MAC associated with an interface to the tunnel, and wherein the step of transmitting data intended for the data path comprises receiving the data on the second MAC associated with an interface to the source, looping the data through the first MAC associated with the data path, and outputting the data via the third MAC associated with the interface to the tunnel.
6. The method of claim 1 , further comprising the step of establishing the tunnel to the second access point.
7. The method of claim 6 , further comprising the step of temporarily buffering data associated with the data path received after receipt of the request to extend the data path and before the tunnel to the second access point is established.
8. The method of claim 1 , further comprising receiving by the first access point, a notification from the mobile unit that the data path will be extended to pass through the second access point.
9. A method of enabling a data path between a first access point in a wireless network and a mobile unit to be extended to pass through a second access point in the same wireless network during a handoff process within the wireless network between the first and second access points, such that the data path extends from the first access point, to the second access point, and then to the mobile unit during at least a part of the handoff process between base stations within the same wireless network, the method comprising the steps of:
receiving, by the second access point in the wireless network, a request from the mobile unit to have the data path extended from the first access point in the wireless network to pass through the second access point in the same wireless network so that data may be tunneled from the first access point to the second access point and provided by the second access point to the mobile unit during the handoff process between the first and second access points within the same wireless network before completion of the handoff process;
transmitting a request by the second access point to the first access point, to request the first access point to extend the data path between the first access point and the mobile unit over a tunnel from the first access point to the second access point so that data may be transmitted by the second access point to the mobile unit prior to completion of the handoff process between the first and second access points in the wireless network.
10. The method of claim 9 , further comprising the step of establishing, by the second access point, a second tunnel between the second access point and the mobile unit.
11. The method of claim 10 , further comprising the step of receiving over the first tunnel, by the second access point, data for transmission to the mobile unit.
12. The method of claim 11 , wherein the step of establishing the second tunnel comprises encapsulating the data received over the first tunnel into at least one wireless management frame for transmission on the wireless network.
13. The method of claim 9 , wherein the data path has at least security and quality of service parameters established by the first access point, and wherein the second access point does not re-establish the security or quality of service parameters associated with the data path.
14. The method of claim 9 , further comprising the steps of:
receiving over the first tunnel, by the second access point, data for transmission to the mobile unit;
commencing transmitting, by the second access point, the data to the mobile unit; and
performing handover messaging with the mobile unit after commencing transmitting the data to the mobile unit so that the timing of handover messaging is decoupled from transmitting the data to the mobile unit.
15. A system, comprising:
a first wireless access point in a first wireless network;
a second wireless access point in the first wireless network; and
a mobile unit;
wherein a wireless data path with defined parameters is established between the mobile unit and the first wireless access point;
wherein a first tunnel is established between the first wireless access point and the second wireless access point; and
wherein the wireless data path is extended via the first tunnel to extend through the second wireless access point without requiring the second access point to reestablish the defined parameters for the wireless data path before data may be transmitted over the extended data path from the first wireless access point to the mobile unit via the second wireless access point.
16. The system of claim 15 , wherein a second tunnel is established between the second wireless access point and the mobile unit, said second tunnel being configured to carry data on the wireless data path between the second wireless access point and the mobile unit.
17. The system of claim 16 , wherein the second tunnel is formed by encapsulating the data in management frames of a wireless protocol.
18. The system of claim 17 , wherein the wireless protocol is one of at least the protocols defined by IEEE 802.11, 802.15, and 802.16.
19. The system of claim 16 , wherein the defined parameters comprise at least quality of service and security.
20. The system of claim 15 , wherein the first tunnel is established using secure tunnel messaging.
21. The system of claim 15 , wherein the first
a first and second wireless access points are instantiated as logical entities on a network element.
22. The system of claim 21 , wherein the first wireless access point has a first Media Access Control (MAC) configured with the defined parameters associated with the data path,
wherein the second wireless access point has a second MAC configured to handle the traffic on the data path without having the parameters associated with the data path redefined.
23. The system of claim 22 , wherein the first tunnel is established between the first MAC and second MAC by causing data to be transferred directly between the first and second MACs.