System and method for hybrid coordination in a wireless LAN

• US 7,330,472 B2
• Filed: 10/16/2002
• Issued: 02/12/2008
• Est. Priority Date: 10/26/2001
• Status: Active Grant

• Current Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Sharp Laboratories of America Incorporated (Hon Hai Precision Industry Co., Ltd.)
• Inventors: Kowalski, John
• Primary Examiner(s): To; Doris H.
• Assistant Examiner(s): GREY, CHRISTOPHER P
• Application Number:
  US10/272,641
• Publication Number:
  US 20030081583A1
• Time in Patent Office: 1,945 Days
• Field of Search: None
• US Class Current: 370/395.21
• CPC Class Codes: H04W 4/00 Services specially adapted for wireless communication networks; Facilities therefor
• CPC Class Codes: H04W 48/08 Access restriction or access information delivery, e.g. discovery data delivery signalling during connection H04W76/00
• CPC Class Codes: H04W 72/20 Control channels or signalling for resource management
• CPC Class Codes: H04W 76/10 Connection setup
• CPC Class Codes: H04W 84/12 WLAN [Wireless Local Area Networks]

Abstract

A system and method are provided for maintaining a hybrid coordinator (HC) in a wireless communications local area network (LAN). The method comprises: a station (STA) seeking a guaranteed quality of service (QoS); establishing a basic service set (BSS) through association with an access point (AP); the AP selecting a HC from STAs in the BSS; the AP broadcasting the HC information to STAs in the BSS; and, the STA initiating a transmission specification (TSPEC) with the HC. In one aspect, selecting an HC from STAs in the first BSS includes integrating the HC function into the AP. Then, a STA seeking a guaranteed quality of service (QoS): receives a broadcast message including a list of potential APs; and, communicates with an AP from the broadcast list. If the STA is unable to communicate with an established AP, then it instantiates a BSS with itself as the AP.

Claims

1. A method for maintaining a hybrid coordinator (HG) in a wireless communications local area network (LAN), the method comprising:

a first station (STA) seeking a guaranteed quality of service (QoS) by sending a probe messages to a first AP requesting the identity of an HC and communicating its eligibility for performing an HC task;

establishing a first basic service set (BSS) through association with a first access point (AP);

the first AP selecting the first HC from STAs in the first BSS as follows;

the first AP sending a response to the first STA with the identity of the first HC; and

,

if there is no first HC, selecting a first HC;

the first AP broadcasting the first HC information selected from a group consisting of media access control (MAC) address and capabilities, to STAs in the first BBS;

the first HC maintaining a QoS table including information selected from a group consisting of STA streams being managed, STAs receiving QoS, QoS parameters, and transmit queue state; and

,

the first STA initiating a transmission specification (TSPEC) with the first HC

wherein the first AP selecting the first HC from STAs in the first BSS includes intergrating the HC function into the first AP

wherein establishing the first BSS with the first AP includes;

the first STA being unable to communicate with an established AP; and

,

the first STA issuing a MAC layer Management Entity START (MLME-STARt) primitive, instantiating a first BSS with itself as the first AP.

2. The method of claim 1 further comprising:

the first AP losing communication with the first HC;

the first AP accepting the QoS table from the first HC;

the first AP selecting a second HC to replace the first HC; and

,

the first AP sending the QoS table to the second HC.

3. The method of claim 2 further comprising:

following the selection of the second HC, the first STA initiating a new TSPEC with the second HC.

4. The method of claim 3 wherein losing communication with the first HC includes the first AP making a determination based on AP communication considerations selected from the group including received power level, channel quality, and frame error rate, and the ability of the first HC to communicate with STAs requesting a QoS in the first BSS.

5. The method of claim 1 wherein selecting a first HC from STAs in the first BSS includes the first AP selecting as follows:

in response to maintaining a candidate HC list; and

,

in response to a request from an HC candidate STA.

6. The method of claim 1 further comprising:

the first HC sending a message to the first AP announcing the disestablishment of its HC function;

the first AP broadcasting the first HC disestablishment announcement to STAs in the BSS; and

,

the first AP selecting a second HC to replace the first HC.

7. The method of claim 1 further comprising:

the first HC sending a message to the first AP announcing its separation from the first BSS;

the first AP broadcasting the first HP separation announcement to STAs in the first BSS; and

,

the first AP selecting a second HC to replace the first HC.

8. The method of claim 1 wherein a first STA seeking a guaranteed quality of service (QoS) includes:

the first STA receiving a broadcast message including a list of potential APs; and

,

communicating with an AP from the list.

9. The method of claim 1 further comprising:

the first AP determining that communication with the first STA is no longer feasible;

the first AP sending a dissociation message to all STAs in the first BSS receiving a QoS;

the first STA communicating to become associated with a second AP; and

,

the first STA initiating a new TSPEC with the second AP.

10. The method of claim 9 further comprising:

the first AP communicating to become associated as a STA with a second AP.

11. A system for maintaining a hybrid coordinator (HC) in a wireless communications local area network (LAN), the system comprising:

a first HC having a wireless communications port for managing guaranteed quality of service (QoS) functions, the first HC maintaining a QoS table including information selected from a group consisting of STA streams being managed, STAs receiving QoS, QoS parameters, and transmit queue state;

a first access point (AP) for selecting the first HC, the first AP including a wireless communications port to broadcast HC information selected from a group consisting of the media access control (MAC) address and capabilities;

a first basic service set (BSS) including the first AP and the first HC;

at least a first station (STA) in the first BSS having a wireless communications port for requesting a guaranteed quality of service (QoS) from the first AP by sending a probe message to the first AP requesting the identity of the first HC, the first STA sending an indication to the first AP as to whether the first STA is eligible to perform the HC task and initiating a transmission specification (TSPEC) with the first HC;

wherein the first HC is a STA in the first BSS; and

,

wherein the first AP sends a message to the first STA with the identity of the first HC, and if there is no first HC, selects a STA in the first BSS as the first HC

wherein the first HC is the first AP,

wherein the first STA is unable to communicate with an established AP and issues a MAC layer Management Entity START (MLME-STARt) primitive, instantiating the first BSS with itself as the first AP.

12. The system of claim 11 wherein the first AP requests the QoS table from the first HC in response to losing communication with the first HC, the first AP selecting a second HC and sending the QoS table to the second HC.

13. The system of claim 12 wherein the first STA, following the selection of the second HC, initiates a new TSPEC with the second HC.

14. The system of claim 13 wherein the first AP determines whether it is losing communication with the HC based on considerations selected from the group including AP communication received power levels, channel quality, and frame error rate, and the ability of the first HC to communicate with STAs in the first BSS requesting a QoS.

15. The system of claim 11 wherein the first AP includes a candidate HC list and selects an HC in response to the candidate list.

16. The system of claim 11 wherein the first STA makes a request to the first AP to become an HC candidate;

and,

wherein the first AT selects an HC in response to HC candidate requests.

17. The system of claim 11 wherein the first HC sends a message to the first AP announcing the disestablishment of its HC function;

and,

wherein the first AP broadcasts the first HC disestablishment announcement to STAs in the first BSS receiving a QoS, and selects a second HC to replace the first HC.

18. The system of claim 11 wherein the first HC sends a message to the first AP announcing its separation from the first BSS;

and,

wherein the first AP broadcasts the first HP separation announcement to STAB in the first BSS receiving a QoS and selects a second HC to replace the first HC.

19. The system of claim 11 wherein the first STA receives a broadcast message including a list of potential APs and communicates with an AP from the broadcast list.

20. The system of claim 11 wherein the first STA includes a list of potential APs and communicates with an AP from the broadcast list.

21. The system of claim 11 wherein the first AP determines that communication with the first STA is no longer feasible and sends a dissociation message to all STAs in the first BSS receiving a QoS;

and,

the system further comprising;

at least a second BSS with a second AP; and

,

wherein the first STA communicates to become associated with the second AP and initiates a new TSPEC with the second AP.

22. The system of claim 21 wherein the first AP communicating to become associated as a STA with a second AP.