Collaboration between wireless LAN access points using wired lan infrastructure

• US 20030207698A1
• Filed: 10/17/2002
• Published: 11/06/2003
• Est. Priority Date: 05/06/2002
• Status: Active Grant

• Current Assignee: Allied Telesis Israel Ltd.
• Original Assignee: Extricom Limited (Allied Telesis Holdings KK)
• Inventors: Shpak, Eran
• Granted Patent: US 6,799,054 B2
• Time in Patent Office: Days
• US Class Current: 455/525
• CPC Class Codes: H04L 47/245 using preemption
• CPC Class Codes: H04W 48/20 Selecting an access point
• CPC Class Codes: H04W 52/08 Closed loop power control
• CPC Class Codes: H04W 52/40 during macro-diversity or soft handoff
• CPC Class Codes: H04W 84/12 WLAN [Wireless Local Area Networks]
• CPC Class Codes: H04W 88/02 Terminal devices
• CPC Class Codes: H04W 88/08 Access point devices
• CPC Class Codes: H04W 92/02 Inter-networking arrangements
• CPC Class Codes: H04W 92/20 between access points

Abstract

A method for mobile communication includes arranging a plurality of access points in a wireless local area network (WLAN) to communicate on a common frequency channel with a mobile station, and linking the access points together by cables in a wired local area network (LAN). When one or more of the access points receive an uplink signal transmitted over the WLAN by the mobile station on the common frequency channel, the access points send messages over the LAN and arbitrate among themselves based on the messages so as to select one of the access points to respond to the uplink signal.

Claims

1. A method for mobile communication, comprising:

arranging a plurality of access points in a wireless local area network (WLAN) to communicate on a common frequency channel with a mobile station;

linking the access points together by cables in a wired local area network (LAN);

receiving at one or more of the access points an uplink signal transmitted over the WLAN by the mobile station on the common frequency channel;

sending one or more messages over the LAN among the access points, responsive to receiving the uplink signal;

arbitrating among the access points based on the messages so as to select one of the access points to respond to the uplink signal; and

transmitting a response from the selected one of the access points to the mobile station.

2. A method according to claim 1, wherein linking the access points comprises arranging the access points to convey data to and from the mobile station via the LAN, in addition to sending the messages over the LAN responsive to receiving the uplink signal.

3. A method according to claim 2, wherein arranging the access points to convey the data comprises configuring the access points to convey the data in accordance with a first media access control (MAC) protocol characterized by a first latency, and wherein sending the messages comprises using a second MAC protocol, having a second latency lower than the first latency, to send the messages responsive to receiving the uplink signal.

4. A method according to claim 3, wherein the first MAC protocol comprises an Ethernet protocol.

5. A method according to claim 3, wherein sending the messages comprises preempting conveying the data in accordance with the first MAC protocol in order to send the messages using the second MAC protocol.

6. A method according to claim 5, wherein preempting conveying the data comprises invoking a collision-avoidance mechanism provided by the first MAC protocol.

7. A method according to claim 5, wherein preempting conveying the data comprises interrupting transmission of a frame of the data in accordance with the first MAC protocol.

8. A method according to claim 1, wherein sending the one or more messages comprises sending broadcast messages from the access points receiving the uplink signal to the plurality of the access points.

9. A method according to claim 1, wherein arbitrating among the access points comprises receiving and processing the messages at each of the plurality of the access points, so that each of the one or more of the access points receiving the uplink signal determines which one of the access points is to be selected to respond to the uplink signal.

10. A method according to claim 9, wherein processing the messages comprises selecting, responsive to the messages, the one of the access points that was first to receive the uplink signal.

11. A method according to claim 1, wherein the access points have respective service areas, and wherein arranging the plurality of the access points comprises arranging the access points so that the service areas substantially overlap.

12. A method according to claim 1, wherein arranging the plurality of the access points comprises arranging the access points to communicate with the mobile station substantially in accordance with IEEE Standard 802.11.

13. A method according to claim 12, wherein arbitrating among the access points comprises selecting the one of the access points to respond to the uplink signal within a time limit imposed by the IEEE Standard 802.11 for acknowledging the uplink signal.

22. A system according to claim 1, wherein the access points are arranged to convey data to and from the mobile station via the LAN, in addition to sending the messages over the LAN responsive to receiving the uplink signal.

23. A system according to claim 22, wherein the access points are configured to convey the data in accordance with a first media access control (MAC) protocol characterized by a first latency, and to send the messages responsive to receiving the uplink signal using a second MAC protocol, having a second latency lower than the first latency.

24. A system according to claim 23, wherein the first MAC protocol comprises an Ethernet protocol.

25. A system according to claim 23, wherein the access points are adapted to preempt conveying the data in accordance with the first MAC protocol in order to send the messages using the second MAC protocol.

26. A system according to claim 25, wherein the access points are arranged to preempt conveying the data by invoking a collision-avoidance mechanism provided by the first MAC protocol.

27. A system according to claim 25, wherein the access points are adapted to preempt conveying the data by interrupting transmission of a frame of the data in accordance with the first MAC protocol.

14. A method for network communication, comprising:

linking a plurality of nodes together in a local area network (LAN);

conveying data over the LAN among the nodes in accordance with a first media access control (MAC) protocol characterized by a first latency; and

preempting conveying the data in accordance with the first MAC protocol in order to pass a message over the LAN among the nodes using a second MAC protocol, having a second latency lower than the first latency.

15. A method according to claim 14, wherein the first MAC protocol comprises an Ethernet protocol.

16. A method according to claim 15, wherein preempting conveying the data comprises asserting a signal in accordance with a media independent interface (MII) between physical and MAC layers of the Ethernet protocol.

17. A method according to claim 14, wherein preempting conveying the data comprises invoking a collision-avoidance mechanism provided by the first MAC protocol.

18. A method according to claim 14, wherein preempting conveying the data comprises interrupting transmission of a frame of the data in accordance with the first MAC protocol.

19. A method according to claim 14, wherein conveying the data comprises establishing a synchronization between the nodes on the LAN in accordance with the first MAC protocol, and wherein preempting conveying the data comprises using the established synchronization to send the message using the second MAC protocol.

20. A method according to claim 14, wherein conveying the data comprises sending data frames including a first type of error detection code, and wherein preempting conveying the data comprises sending the message with a second type of error detection code, different from the first type.

21. A system for mobile communication, comprising:

cables arranged to form a wired local area network (LAN); and

a plurality of access points interconnected by the LAN and arranged in a wireless local area network (WLAN) to communicate on a common frequency channel with a mobile station, the access points being adapted, upon receiving at one or more of the access points an uplink signal transmitted over the WLAN by the mobile station on the common frequency channel, to send one or more messages over the LAN among the access points, responsive to receiving the uplink signal, and to arbitrate among the access points based on the messages so as to select one of the access points to respond to the uplink signal, and to transmit a response from the selected one of the access points to the mobile station.

28. A system according to claim 21, wherein the one or more messages comprise broadcast messages, sent from the access points receiving the uplink signal to the plurality of the access points.

29. A system according to claim 21, wherein the access points are adapted to receive and process the messages so that each of the one or more of the access points receiving the uplink signal determines which one of the access points is to be selected to respond to the uplink signal.

30. A system according to claim 29, wherein the access points are adapted to select, responsive to the messages, the one of the access points that was first to receive the uplink signal.

31. A system according to claim 21, wherein the access points have respective service areas, and wherein the access points are arranged so that the service areas substantially overlap.

32. A system according to claim 21, wherein the access points are adapted to communicate with the mobile station substantially in accordance with IEEE Standard 802.11.

33. A system according to claim 32, wherein the access points are adapted to select the one of the access points to respond to the uplink signal within a time limit imposed by the IEEE Standard 802.11 for acknowledging the uplink signal.

34. A system for network communication, comprising:

cables arranged to form a wired local area network (LAN); and

a plurality of nodes, which are linked together by the LAN and are adapted to convey data over the LAN among the nodes in accordance with a first media access control (MAC) protocol characterized by a first latency, and which are further adapted to preempt conveying the data in accordance with the first MAC protocol in order to pass a message over the LAN among the nodes using a second MAC protocol, having a second latency lower than the first latency.

35. A system according to claim 34, wherein the first MAC protocol comprises an Ethernet protocol.

36. A system according to claim 35, wherein the nodes are adapted to preempt conveying the data by asserting a signal in accordance with a media independent interface (MII) between physical and MAC layers of the Ethernet protocol.

37. A system according to claim 34, wherein the nodes are adapted to preempt conveying the data by invoking a collision-avoidance mechanism provided by the first MAC protocol.

38. A system according to claim 34, wherein the nodes are adapted to preempt conveying the data by interrupting transmission of a frame of the data in accordance with the first MAC protocol.

39. A system according to claim 34, wherein the nodes are adapted to establish a synchronization between the nodes on the LAN in accordance with the first MAC protocol, and to use the established synchronization to send the message using the second MAC protocol.

40. A system according to claim 34, wherein the nodes are adapted to convey the data by sending data frames including a first type of error detection code, and to send the message with a second type of error detection code, different from the first type.

41. Access point apparatus for deployment in a wireless local area network (WLAN) as one of a plurality of access points for mobile communication, the apparatus comprising:

a radio transceiver, which is configured to communicate on a predetermined frequency channel with a mobile station;

a physical layer interface, for connecting the access point to a wired local area network (LAN) interconnecting the access points; and

processing circuitry, which is adapted, when the transceiver receives an uplink signal transmitted over the WLAN by the mobile station on the predetermined frequency channel, to send and receive messages via the physical layer interface over the LAN to and from the plurality of access points, and to arbitrate among the access points based on the messages so as to select one of the access points to respond to the uplink signal, and to control the transceiver so that the transceiver returns a response to the mobile station subject to the arbitration protocol.

42. Apparatus according to claim 41, wherein the processing circuitry is further adapted to convey data to and from the mobile station over the LAN via the physical layer interface, in addition to sending and receiving the messages over the LAN responsive the uplink signal.

43. Apparatus according to claim 42, wherein the processing circuitry is adapted to convey the data in accordance with a first media access control (MAC) protocol characterized by a first latency, and to send and receive the messages responsive to receiving the uplink signal using a second MAC protocol, having a second latency lower than the first latency.

44. Apparatus according to claim 43, wherein the first MAC protocol comprises an Ethernet protocol.

45. Apparatus according to claim 43, wherein the processing circuitry is adapted to preempt conveying the data in accordance with the first MAC protocol in order to send the messages using the second MAC protocol.

46. Apparatus according to claim 45, wherein the processing circuitry comprises a multiplexer, which is adapted invoke a collision-avoidance mechanism provided by the first MAC protocol in order to preempt conveying the data.

47. Apparatus according to claim 46, wherein the processing circuitry comprises a MAC processor, which is adapted to generate frames of the data for transmission in accordance with the first MAC protocol, and wherein the multiplexer is adapted to use the collision-avoidance mechanism in order to cause the MAC processor to interrupt transmission of one of the frames of the data.

48. Apparatus according to claim 41, wherein the messages sent and received by the processing circuitry responsive to receiving the uplink signal comprise broadcast messages, sent from the access points receiving the uplink signal to the plurality of the access points.

49. Apparatus according to claim 41, wherein the processing circuitry is adapted to receive and process the messages so that each of the one or more of the access points receiving the uplink signal determines which one of the access points is to be selected to respond to the uplink signal.

50. Apparatus according to claim 49, wherein the processing circuitry is adapted to select, responsive to the messages, the one of the access points that was first to receive the uplink signal.

51. Apparatus according to claim 41, wherein the transceiver is adapted to communicate with the mobile station substantially in accordance with IEEE Standard 802.11.

52. Apparatus according to claim 51, wherein the processing circuitry is adapted to select the one of the access points to respond to the uplink signal within a time limit imposed by the IEEE Standard 802.11 for acknowledging the uplink signal.

53. Node apparatus for deployment as one of a plurality of nodes in a local area network (LAN), the apparatus comprising:

a physical layer interface, for connecting the node to the LAN; and

processing circuitry, which is adapted to convey data via the physical layer interface over the LAN in accordance with a first media access control (MAC) protocol characterized by a first latency, and which is further adapted to preempt conveying the data in accordance with the first MAC protocol in order to pass a message over the LAN using a second MAC protocol, having a second latency lower than the first latency.

54. Apparatus according to claim 53, wherein the first MAC protocol comprises an Ethernet protocol.

55. Apparatus according to claim 54, wherein the processing circuitry comprises:

a first MAC processor, for conveying the data in accordance with the first MAC protocol;

a second MAC processor, for sending and receiving the message in accordance with the second MAC protocol; and

a multiplexer, coupling the first and second MAC processors to the physical layer interface, which is adapted to preempt the first MAC processor so as to enable the second MAC processor to send the message.

56. Apparatus according to claim 55, wherein the first MAC protocol comprises an Ethernet protocol, and wherein the multiplexer is adapted to preempt the first MAC processor by asserting a signal in accordance with a media independent interface (MII) between physical and MAC layers of the Ethernet protocol.

57. Apparatus according to claim 55, wherein the multiplexer is adapted to preempt the first MAC processor by invoking a collision-avoidance mechanism provided by the first MAC protocol.

58. Apparatus according to claim 55, wherein the multiplexer is adapted, upon preempting the first MAC processor, to interrupt transmission of a frame of the data generated by the first MAC processor.

59. Apparatus according to claim 55, wherein the first MAC processor is adapted to generate data frames including a first type of error detection code, and wherein the second MAC processor is adapted to generate the message with a second type of error detection code, different from the first type.

60. Apparatus according to claim 54, wherein the physical layer interface is adapted to establish a synchronization between the nodes on the LAN in accordance with the first MAC protocol, and to use the established synchronization to send the message using the second MAC protocol.