Mobility support via routing

• US 7,672,274 B2
• Filed: 04/25/2002
• Issued: 03/02/2010
• Est. Priority Date: 01/11/2002
• Status: Active Grant

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: Broadcom Corporation (Broadcom, Inc.)
• Inventors: Bims, Harry
• Primary Examiner(s): Yao; Kwang B
• Assistant Examiner(s): Lai; Andrew
• Application Number:
  US10/133,789
• Publication Number:
  US 20030133422A1
• Time in Patent Office: 2,868 Days
• Field of Search: 370/338, 370/331, 370/332, 370/333, 370/334
• US Class Current: 370/332
• CPC Class Codes: H04L 1/16 in which the return channel carries supervisory signals, e.g. repetition request signals
• CPC Class Codes: H04L 12/189 in combination with wireless systems selective distribution or broadcast in wireless communication networks H04W4/06
• CPC Class Codes: H04L 2001/0097 Relays
• CPC Class Codes: H04L 45/00 Routing or path finding of packets in data switching networks routing or path finding in wireless networks H04W40/00
• CPC Class Codes: H04W 36/08 Reselecting an access point
• CPC Class Codes: H04W 40/00 Communication routing or communication path finding
• CPC Class Codes: H04W 40/02 Communication route or path selection, e.g. power-based or shortest path routing
• CPC Class Codes: H04W 80/00 Wireless network protocols or protocol adaptations to wireless operation
• CPC Class Codes: H04W 84/12 WLAN [Wireless Local Area Networks]
• CPC Class Codes: H04W 88/04 adapted for relaying to or from another terminal or user
• CPC Class Codes: H04W 88/12 Access point controller devices

Abstract

A communication system is described. In one embodiment, the communication system comprises a mobile station having a transmitter to transmit packets wirelessly according to a protocol and multiple repeaters communicably coupled with the mobile station. Each of the plurality of repeaters receives one or more packets of the wirelessly transmitted packets from the mobile station. Each of the repeaters receives an indication of which of the wirelessly transmitted packets were received without errors by other repeaters and a received signal strength for those packets. The communication system also includes a switch coupled to the repeaters. Each of the repeaters forwards to the switch each packet of the wirelessly transmitted packets that each repeater had received without errors at a received signal strength higher than any other repeater.

Claims

1. A routing method for enhancing mobility of a mobile station, comprising:

communicating packets with the mobile station using a first port on a switch and a first repeater coupled to the first port, wherein a media access control (“

MAC”

) layer functionality is split between a switch MAC sublayer associated with the switch and a corresponding first repeater MAC sublayer associated with the first repeater;

changing to use a second port on the switch to communicate with the mobile station, the second port being different than the first port and coupled to a second repeater different than the first repeater and having a corresponding second repeater MAC sublayer, wherein the changing step is accomplished by the switch using the switch MAC sublayer and occurs when the switch determines that the mobile station is closer to the second repeater based on a comparison of received signal strength from duplicate packets received on the first and second repeaters; and

communicating packets with the mobile station using the second port and the second repeater, whereby mobility provisions of IEEE 802.11 protocol are ignored during the changing step.

2. The method of claim 1, wherein the first and second ports are Ethernet ports and are connected to the first and second repeaters, respectively, via Ethernet connections.

3. The method of claim 1, further comprising:

accessing at the switch a listing of a plurality of mobile stations, including a first mobile station, and an indication of a closest repeater for each of the plurality of mobile stations;

determining that the first mobile station is closer to the second repeater than the first repeater; and

updating the listing to reflect that the second repeater is closest to the first mobile station.

4. A switch for routing packets to and from a mobile station, comprising:

means for communicating packets with the mobile station using a first port on the switch and a first repeater coupled to the first port, wherein a media access control (“

MAC”

) layer functionality is split between a switch MAC sublayer associated with the switch and a corresponding first repeater MAC sublayer associated with the first repeater;

means for changing to use a second port on the switch to communicate with the mobile station, the second port being different than the first port and coupled to a second repeater different than the first repeater and having a corresponding second repeater MAC sublayer, wherein the changing means is accomplished by the switch using the switch MAC sublayer and includes means for determining that the mobile station is closer to the second repeater and means for changing to use the second port based thereon; and

means for communicating packets with the mobile station using the second port and the second repeater, whereby mobility provisions of IEEE 802.11 protocol are ignored during the changing step.

5. The switch of claim 4, wherein the means for determining that the mobile station is closer to the second repeater comprises:

means for monitoring the received signal strength of duplicate packets received from the first and second repeaters.

6. The switch of claim 4, wherein the first and second ports are Ethernet ports and are connected to the first and second repeaters, respectively, via Ethernet connections.

7. The switch of claim 4, further comprising:

means for accessing a listing of a plurality of mobile stations, including a first mobile station, and an indication of a closest repeater for each of the plurality of mobile stations;

means for determining that the first mobile station is closer to the second repeater than the first repeater; and

means for updating the listing to reflect that the second repeater is closest to the first mobile station.

8. The switch of claim 7, wherein the means for determining that the first mobile station is closer to the second repeater comprises means for monitoring the received signal strength of duplicate packets received from the first and second repeaters.

9. A method for routing mobile stations, comprising:

exchanging packets with a mobile device through a first repeater using a first port on a switch coupled to the first repeater, wherein a media access control (“

MAC”

) layer functionality is split between a first repeater MAC sublayer and a corresponding switch MAC sublayer;

performing, by the switch MAC sublayer, a routing handoff by selecting a second port on the switch, different than the first port, the second port being connected to a second repeater having a second repeater MAC sublayer corresponding to the switch MAC sublayer, wherein the routing handoff occurs when the switch determines that the mobile device is closer to the second repeater based on a comparison of received signal strength from duplicate packets received on the first and second repeaters; and

exchanging packets with the mobile device through the second repeater using the second port on the switch,

whereby mobility provisions of IEEE 802.11 protocol are ignored during the routing handoff.

10. An apparatus for routing packets to and from a mobile station, comprising:

a plurality of repeaters communicably coupled with a first mobile station, wherein each of the plurality of repeaters receives one or more wirelessly transmitted packets from the first mobile station; and

a switch coupled to the plurality of repeaters to receive wirelessly transmitted packets from the plurality of repeaters through wired connections between the switch and the plurality of repeaters,

wherein a media access control (“

MAC”

) layer functionality is split between a plurality of repeater MAC sublayers and a corresponding switch MAC sublayer,

wherein the switch has a port for each of the plurality of repeaters,

wherein the switch communicates packets with the first mobile station using a first port on the switch and a first repeater of the plurality of repeaters and subsequently changes to use a second port on the switch to communicate with the first mobile station, the second port being different than the first port and connected to a second repeater different than the first repeater, and

wherein the change to the second port is accomplished by the switch using the switch MAC sublayer and occurs when the switch determines that the mobile station is closer to the second repeater based on a comparison of received signal strength from duplicate packets received on the first and second repeaters, whereby mobility provisions of IEEE 802.11 protocol are ignored during the change to the second port.

11. The apparatus of claim 10, further comprising:

a listing of a plurality of mobile stations, including the first mobile station, and an indication of a closest repeater of the plurality of repeaters for each of the plurality of mobile stations, wherein the switch determines that the first mobile station is closer to the second repeater than the first repeater and updates the listing to reflect that the second repeater is closest to the first mobile station.

12. The apparatus of claim 11, wherein the wired connections comprise Ethernet connections and the port of each of the plurality of repeaters is an Ethernet port.