Address resolution protocol-based wireless access point method and apparatus

• US 8,160,067 B2
• Filed: 06/19/2006
• Issued: 04/17/2012
• Est. Priority Date: 06/21/2005
• Status: Active Grant

• Current Assignee: Google Technology Holdings LLC (Alphabet Inc.)
• Original Assignee: Motorola Mobility, Inc. (Lenovo Group Ltd.)
• Inventors: Bedekar, Anand S., Agrawal, Rajeev, Gopikanth, Venkat, Kalyanasundaram, Suresh, Ram Ov, Vishnu
• Primary Examiner(s): Kizou, Hassan
• Assistant Examiner(s): Shand, Roberta A
• Application Number:
  US11/913,940
• Publication Number:
  US 20080205362A1
• Time in Patent Office: 2,129 Days
• Field of Search: 370/349, 370/352, 370/389, 370/390, 370/392, 370/395.54, 709/242, 4554321-4351
• US Class Current: 370/392
• CPC Class Codes: H04L 61/103 across network layers, e.g. resolution of network layer into physical layer addresses or address resolution protocol [ARP]
• CPC Class Codes: H04W 8/26 Network addressing or numbering for mobility support
• CPC Class Codes: H04W 80/00 Wireless network protocols or protocol adaptations to wireless operation
• CPC Class Codes: H04W 88/08 Access point devices

Abstract

A wireless access point (200), upon determining (101) that a need exists to support a communication need of a mobile station, acquires (102) a first Internet Protocol (IP) address and automatically transmits (103) a gratuitous Address Resolution Protocol message to a local router to thereby cause the latter to correlate the first IP address to a Medium Access Control address for the wireless access point. In a preferred embodiment the wireless access point can also automatically transmit a registration request to a remote network element (such as a Home Agent) that presents this first IP address as a care-of address to use in conjunction with another IP address that serves as a home address for the mobile station.

Claims

1. A method for routing data comprising:

determining a need to support at least one communication need of a mobile station;

acquiring, by a first wireless access point of a subnet that comprises a plurality of wireless access points, a first Internet Protocol address used in association with the mobile station by a second wireless access point of the plurality of wireless access points;

automatically transmitting, by the first wireless access point, a gratuitous Address Resolution Protocol message to a router that shares the same subnet as the wireless access point, to thereby cause the router to correlate the first Internet Protocol address to a Medium Access Control address for the first wireless access point;

automatically transmitting a registration request to a network element that is remote to the subnet, wherein the registration request presents a second Internet Protocol address as a home address for the mobile station and the first Internet Protocol address as a care-of-address for the mobile station for use by the network element to route data to the mobile station;

receiving, by the first wireless access point from the router and using the Medium Access Control address, data intended for eventual delivery to the mobile station.

2. The method of claim 1 further comprising:

receiving, by the router from the network element, the data intended for eventual delivery to the mobile station and addressed to the first Internet Protocol address;

routing, by the router, the data intended for eventual delivery to the mobile station using the Medium Access Control address of the first wireless access point.

3. The method of claim 2 further comprising:

receiving via the subnet a communication bearing the second Internet Protocol address;

forwarding at least a portion of the communication to the mobile station.

4. The method of claim 1 wherein:

determining a need to support at least one communication need of a mobile station comprises detecting a mobility management event for the mobile station with respect to the wireless access point; and

acquiring a first Internet Protocol address comprises receiving the first Internet Protocol address from another wireless access point.

5. A wireless access point comprising:

a mobile station interface;

an Internet Protocol address that corresponds to a given mobile station that interfaces with the wireless access point via the mobile station interface;

a second Internet Protocol address that the wireless access point acquired via a subnet interface and was used in association with the given mobile station by another wireless access point of the same subnet as the wireless access point, which second Internet Protocol address the wireless access point associates with the given mobile station;

a subnet interface configured and arranged to transmit to a router that shares a same subnet as the wireless access point an Address Resolution Protocol message to thereby cause the router to correlate the second Internet Protocol address to a Medium Access Control address for the wireless access point and to receive, from router and intended for the given mobile station, data routed using the Medium Access Control address;

means for transmitting a registration request to a network element that is remote to the subnet, wherein the registration request presents the Internet Protocol address as a home address for the mobile station and the second Internet Protocol address as a care-of-address for the mobile station; and

wherein the wireless access point forwards the data received from the router to the given mobile station via the mobile station interface and using the Internet Protocol address that corresponds to the given mobile station.

6. The wireless access point of claim 5 wherein the subnet interface comprises means for acquiring the second Internet Protocol address from the subnet.

7. The wireless access point of claim 5 wherein the subnet interface comprises means for acquiring the second Internet Protocol address from one or more of another wireless access point as comprises a part of the subnet and from a Dynamic Host Configuration Protocol server.

8. The wireless access point of claim 5 wherein the subnet interface further comprises means for automatically transmitting a gratuitous Address Resolution Protocol message to the router to thereby cause the router to correlate the second Internet Protocol address to a Medium Access Control address for the wireless access point.

9. A method to facilitate communications via a communication system that comprises, in part, a subnet that itself comprises a plurality of wireless access points, the method comprising:

at a first one of the wireless access points;

detecting a mobile station;

acquiring a local Internet Protocol address from a subnet source to use in correspondence with the mobile station, wherein the local Internet Protocol address is used in association with the mobile station by a second wireless access point of the plurality of wireless access points;

transmitting a gratuitous Address Resolution Protocol message bearing the local Medium Access Control address and another Internet Protocol address that corresponds to the mobile station to a subnet router;

transmitting a registration request to a network element that is remote to the subnet, wherein the registration request presents the another Internet Protocol address as a home address for the mobile station and the local Internet Protocol address as a care-of-address for the mobile station;

at the subnet router;

receiving the gratuitous Address Resolution Protocol message;

correlating the local Internet Protocol address with a Medium Access Control address for the first one of the wireless access points;

receiving, from the network element that is remote to the subnet, a communication intended for the mobile station and bearing the local Internet Protocol address and the another Internet Protocol address;

using the local Internet Protocol address from the communication to identify the Medium Access Control address as correlates thereto;

using the identified Medium Access Control address to forward the communication to the first one of the wireless access points;

at the first one of the wireless access points;

receiving the communication as forwarded by the subnet router;

using the another Internet Protocol address to identify the mobile station; and

forwarding the communication to the mobile station.

10. The method of claim 9 wherein acquiring a local Internet Protocol address from a subnet source to use in correspondence with the mobile station comprises receiving the local Internet Protocol address from one or more of a local Dynamic Host Configuration Protocol server and another wireless access point.