HK1129981A

HK1129981A - Peer-to-peer wireless communication system

Info

Publication number: HK1129981A
Application number: HK09108405.3A
Authority: HK
Inventors: 亚蒂‧钱德拉; 约瑟‧S‧李维; 苏希尔‧A‧格兰帝; 爱尔戴德‧莱尔
Original assignee: 美商内数位科技公司
Priority date: 2005-01-25
Filing date: 2006-01-19
Publication date: 2009-12-11

Description

Point-to-point wireless communication system

Technical Field

The present invention relates to a wireless communication system including a plurality of wireless Stations (STAs) and an Access Point (AP) (i.e., a centralized controller), and a wireless communication system including a plurality of STAs without a centralized controller (i.e., a point-to-point (Ad hoc) network). More particularly, the present invention relates to using a Direct Link Setup (DLS) between the STAs to establish data transmission.

Background

Typically, STAs do not allow direct transmission of data packets to other STAs within a Basic Service Set (BSS), but rather must always rely on the AP to communicate data packets, whereas STAs with quality of service (QoS) devices (i.e., QSTAs) can directly transmit data packets to other QSTAs by establishing data transmissions using DLS. The IEEE802.11e standard relates to supporting QoS features such as service differentiation, block acknowledgement, and DLS, STAs supporting these IEEE802.11e features are referred to as QSTAs, and APs supporting IEEE802.11e features are referred to as QAPs. The reason why the DLS is required is because the STA expected to receive may be in a power save mode, whereby the receiving QSTA is only initiated (i.e., awakened) by the AP with QoS equipment (i.e., QAP), the DLS exchanges rate sets and other information between the transmitter in one QSTA and the receiver in the other QSTA, and the DLS information is also used for additional security Information Elements (IEs).

Disclosure of Invention

The present invention relates to a point-to-point communication system using DLS. A mobile Station (STA) establishes a direct communication link with other STAs by sending a message requesting a DLS from an Access Point (AP) (i.e., a centralized controller) that can accept or reject the DLS request based on channel measurements. If the DLS request is accepted, the DLS is established so that the STAs can communicate directly with each other. An established connection may be severed by the AP sending a message to one of the STAs containing a DLS sever request. The system may be an Ad hoc network comprising a plurality of STAs without APs, wherein each STA maintains a database of STAs of one-hop (one-hop) and two-hop (two-hop) and establishes a direct link with one of the other STAs after notifying neighboring STAs that it intends to establish a direct communication link.

Drawings

The invention will be understood in more detail from the following description of a preferred embodiment, given as an example, and with reference to the accompanying drawings, in which:

FIG. 1 is a block diagram of a wireless communication system including a plurality of QSTAs and a QAP in accordance with the present invention;

FIG. 2 is a block diagram of an Ad hoc network according to the present invention including multiple STAs to support peer-to-peer communication; and

fig. 3 is a block diagram according to the present invention including STAs and an AP to support peer-to-peer communication.

Detailed Description

The terms "STA" or "QSTA" are used herein to include, but are not limited to, a wireless transmit/receive unit (WTRU), a user equipment, a mobile station, a fixed or mobile subscriber unit, a pager, or any other type of device capable of operating in a wireless environment. When referred to hereafter, the terms "AP" or "QAP" include, but are not limited to, a base station, a node B, a site controller, a centralized controller, or any other type of interfacing device in a wireless environment.

The features of the present invention may be incorporated on an Integrated Circuit (IC) or be configured in a circuit comprising a multitude of interconnecting components.

The present invention facilitates the establishment of data transmission between QSTAs in a peer-to-peer wireless communication system, such as a Wireless Local Area Network (WLAN) or a Wireless Wide Area Network (WWAN) using DLS. The present invention further performs a signaling procedure for establishing or cutting off the DLS and performing a data transmission with hybrid coordination function control channel access (HCCA) or Enhanced Distributed Channel Access (EDCA).

More details regarding DSL, HCCA, EDCA are disclosed in U.S. patent application No. 11/199,446, entitled "method and system for controlling access to a wireless communication medium", by Sudheer a.

Fig. 1 is a block diagram of a wireless communication system 100 including a plurality of QSTAs 12a, 12b and a QAP 10. Similar to conventional wireless communication systems, the QSTA12a intends to directly exchange data packets with the QSTA12 b, the QSTA12a requests a DLS by including a DLS request frame in the message 102 sent by the QSTA12a to the QAP 10. The message 102 may include a rate set, capability information of the QSTA12a, the Media Access Control (MAC) addresses of the QSTAs 12a and 12b, or other necessary information. If the QSTA12 b is associated with the QAP 10 in a Basic Service Set (BSS) having permission for direct data transmission between QSTAs, the QAP 10 forwards a DLS request frame in a message 104 to the QSTA 12. if the QSTA12 b accepts the DLS request frame, the QSTA12 b includes a DLS response frame in a message 106 sent by the QSTA12 b containing the rate set to the QAP 10. The QAP 10 includes the DLS response frame in the message 108 sent to QSTA12a, after which a direct communication link 110 is established between the QSTA12a and QSTA12 b.

In accordance with the present invention, the QAP 10 may reject DLS requests from the QSTA12a due to inadequate signal channel quality at the QSTA12a, 12b, and therefore the QAP 10 will not transmit the message 104 to the QSTA12 b. The DLS request frame included in the message 102 contains an IE of the desired physical layer (PHY) rate and/or channel quality information between the QSTAs 12a and 12b, which may be obtained from a previous transmission between QSTA12a and QSTA12 b, or from monitoring transmissions by QSTA12 b (received by the QAP 10 or other QSTAs), and if the information is invalid, the QSTA12a sends the message 102 with IE set to 0.

If the QSTA12a needs to perform the search for the QSTA12 b, the QSTA12a may include a DLS discovery request frame in the message 112 sent to the QAP 10, if the QAP 10 discovers the QSTA12 b, the QAP 10 may include a DLS discovery response frame and associated MAC information in the message 114 sent to the QSTA12a, otherwise, the QAP 10 may include the DLS discovery response frame and an indication in the message 114 indicating that the QSTA12 b cannot be located. This process is performed prior to the establishment of the DLS.

Referring to fig. 1, additional information may be further exchanged before or after DLS setup. The QAP 10 may optionally include a DLS measurement request packet in the message 116 sent to the QSTA12a that has become requesting a channel quality measurement. The information 116 may also include capability information regarding the QSTA12 b performing a channel quality measurement, which may include, but is not limited to: number of antennas, indication of the type of antenna technology support (such as Multiple Input Multiple Output (MIMO)), antenna diversity, or any other smart antenna technology. The QSTA12a responds to the message 116 by including a measurement response packet in a message 118 sent to the QAP 10, the message 118 also including channel quality measurement results between the QSTA12a and QSTA12 b, the channel measurement including: a Received Signal Strength Indicator (RSSI) between QSTA12a to QSTA12 b, a Channel Quality Indicator (CQI) between QSTA12a to QSTA12 b, and an interference level at QSTA12 a. RSSI is measured by QSTA12 b at QSTA12a by passively listening for packets sent by QSTA12 b to the QAP 10 or other QSTAs/STAs; CQI measurements may be obtained by actively transmitting a packet by QSTA12a to QSTA12 b, even before the DLS is implemented. The information 116 and 118 may be exchanged before the information 108 is transmitted by the QAP 10 or during an ongoing DLS.

In conventional wireless communication systems, the DLS may be cut off by one of the QSTAs 12a, 12b, the DLS cut off process cannot be initiated by the QAP 110, and the QSTAs 12a, 12b may cut off the DLS because the application stops or completes. Each of the QSTAs 12a, 12b may include a timer that is reset each time a packet (either a data packet or an Acknowledgement (ACK) packet) is received from the QSTA12a, 12b, the timer being used to terminate the DLS due to a link failure or application completion. If no packet is received before the timer expires or an application has completed, the QSTA's 12a, 12b start a DLS cut-off procedure by including a DLS cut-off packet in the message 120a, 120b sent to the QAP 10. After the DLS cut-off procedure is completed, all packets transmitted by QSTAs 12a, 12b are processed by the QAP 10.

The QSTAs 12a, 12b may transmit the DLS cut packet to the QAP 10, and once the DLS cut information 120 is transmitted by one of the QSTAs 12a, 12b, the QAP 10 will forward the DLS cut information to the other one of the QSTAs 12a, 12 b. The DLS cut-off procedure may be implemented in any access method (e.g., an assignment resource allocation, a management resource allocation, HCCA, or EDCF).

According to the present invention, the QAP 10 may initiate a DLS cut-off process by sending a DLS response message 108 containing a cut-off action field to the QSTAs 12a or 12 b. The action frame includes a timer information field whereby the QSTA12a or 12b must respond by sending a DLS lockout message to the QAP 10 before the timer expires. This feature is previously compatible with current WLAN standards.

The QAP 10 may start a DLS between the two QSTAs 12a and 12b, the QAP 10 transmits a DLS start message to the QSTAs 12a and 12b, and the QAP 10 may transmit a DLS response message to the QSTAs 12a and 12b once the QAP 10 receives a DLS request message corresponding to the DLS start message from the QSTAs 12a and 12 b. The DLS initialization information is a new information introduced by the present invention that allows the QAP 10 to initialize DLS between two STAs. Alternatively, the DLS request message and the DLS response message may be modified so that a DLS is initiated by the QAP 10 instead of generating a new DLS initiation message.

Data transmission after the DLS setup will be explained herein. The QSTAs may use the DLS to perform data transfers using any access mechanism defined by the IEEE802.11e standard, such as HCCA or EDCF.

The present invention provides several action frame formats for DLS management. An action field immediately after the classification field to distinguish the format, the action field value for each frame format being defined in table 1.

Action field value	Of significance
Action field value	Of significance	0	DLS request
1	DLS response	0	DLS request
1	DLS response	2	DLS cleaving
3-255	Retention	2	DLS cleaving

TABLE 1

Additional action field values are defined according to the present invention. A DLS discovery request frame is a frame that a QSTA acquires the MAC address of another QSTA by sending application requests. A DLS discovery response frame responds to the QAP with the MAC address of the requesting QSTA. A conventional DLS chop frame is modified to add an action field for the DLS chopped by the QAP, an information field called a timer is included in the DLS chop frame, the QAP expects that the QSTA will send the DLS chop information to the QAP before the timer expires. A conventional DLS request frame is modified to include an additional element to transmit the optimized PHY data rate and certain other channel characteristics between the two QSTAs. A DLS measurement request frame is a measurement request from a QAP to a QSTA, the DLS measurement request frame containing capability information of another QSTA. A DLS measurement response frame is for a DLS measurement response from a QSTA to a QAP, the DLS measurement response frame including measurement information and another QSTA MAC address.

Fig. 2 is a block diagram of an AD hoc network 200 according to the present invention including a plurality of QSTAs 12a, 12b, 12c, 12d, 12e, 12f supporting peer-to-peer communications. Each QSTA12 a-12f maintains a database (not shown) of all QSTAs 12a-12f within a hop, or two hops, a hop QSTAs being QSTAs that can listen to each other and will be referred to as a "neighbor" hereinafter, and a hop QSTAs that cannot directly listen to but a "neighbor" is audible.

When the medium is in use, both QSTAs groups need to be informed, i.e., QSTAs that can listen for transmissions and QSTAs that may transmit and interfere with reception. Therefore, only one transmitting QSTA and one receiving QSTA need to inform their neighboring QSTAs separately, the transmitting QSTA needs to distinguish the neighbor that is using the medium, and the neighbor cannot receive without interference. The receiving QSTA needs to know the neighbor that is using the medium and the neighbor cannot transmit. This requires some handshaking mechanism for proper implementation, but may result in better overall media utility.

Neighboring QSTAs signal to each other to report capabilities via capability information that may be part of an initialization procedure when a QSTA is powered up, which may be triggered periodically or by some active or inactive event of any QSTA, or may also be in response to an information request signal initiated by one of the QSTAs.

A new QSTA may send a broadcast message to the neighbor requesting active transmission, the new QSTA may passively scan the channel and then send packets, after receiving the request, any actively departing QSTA may send the information back to the new QSTA, the QSTAs may follow a random back-off mechanism before responding, and once the new QSTA acquires the information, the new QSTA uses this information for resource allocation optimization to start a new application.

For example, in the Ad hoc network 200 of fig. 2, the QSTA12a and the QSTA12 b want to communicate with each other, and before an application is executed between the QSTA12a and the QSTA12 b, one or both of the QSTA12a and the QSTA12 b must notify neighbors by sending information 202 about the application, which information 202 can be sent and/or propagated to two-hop QSTAs using broadcast. Alternatively, the message 202 may comprise a packet directed to a specific QSTAs, and the QSTA12a and the QSTA12 b may communicate without any interference by exchanging the message 204 after notifying neighboring QSTAs intended to communicate.

The information communicated between the QSTAs 12a, 12b may include, but is not limited to, bandwidth requirements, identification of the transmitting QSTA and the receiving QSTA, frequency band, preferred modulation mode, sub-carrier, MIMO enable code, and the like. This information should preferably be communicated during DLS setup, however, it may also be communicated during DLS communication in order to update certain parameters like preferred modulation. This information may be resent in response to a request by another QSTA, which may request it in order to update its data or start a new application.

Some services or applications may have priority over others, whereby they may interrupt other services if desired, an example of such a service being voice over internet protocol (VoIP) for emergency calls (911). This interruption may be performed by an exchange of information between other transmitting QSTAs to terminate their service, or by an exchange of information to renegotiate bandwidth, sub-carriers, bands, etc.

FIG. 3 is a block diagram of a network 300 including a plurality of QSTAs 12a-12f and a QAP14 in accordance with the present invention. Similar to the Ad hoc network 200 of fig. 2, each of the QSTAs 12a-12f maintains a database of all QSTAs, wherein each of the QSTAs 12a-12f is capable of communicating directly with it and each of the QSTAs 12a-12f is capable of communicating via the QAP14, and the QAP14 is capable of providing a database of valid QSTAs via the QAP 14.

Each of the QSTAs 12a-12f is connected to the QAP14, however, all traffic need not be generated by or flow through the QAP14, so that two QSTAs can communicate directly with each other without sending the traffic through the QAP 14. This process may be controlled by the QAP14 and a distributed control similar to the non-AP embodiment described above with respect to FIG. 2.

In the process controlled by the QAP14, for example, a QSTA12a intends to communicate with a QSTA12 b, the QSTA12a sends a message 302 to the QAP14 that includes at least one of: a target ID, a required bandwidth, channel information, a direct hop to the target, etc. Based on the information provided in the message 302, the QAP14 determines whether the two QSTAs 12a, 12b are to communicate directly or need to communicate through the QAP 14. The QAP14 may make decisions based on the signal strength between the two QSTAs 12a, 12b, the current network load, the activity of the QAP14, the capabilities of the two QSTAs 12a, 12b, and so on. The QAP14 sends a message 304 on demand for the connection that includes allocation information (e.g., a particular time, sub-carrier, or antenna) for the assigned resources and indicates which is valid. A direct communication link is then established between the QSTAs 12a and 12 b.

The assignment information in message 304 is sent to the QSTA12a and QSTA12 b, and the other QSTAs 12c-12f may also be notified of the direct communication link 306 to let them know that the resource is in use. The QSTAs 12c-12f may learn by broadcasting the information 304 to all QSTAs 12a-12f or by requesting all QSTAs 12a-12f to monitor the QAP14 for information 304, which prevents other QSTAs 12a-12f from using the same resources even if they are not being used.

Although the features and elements of the present invention are described in the embodiments in particular combinations, each feature or element can be used alone without the other features and elements of the preferred embodiments or in various combinations with or without other features and elements of the present invention. While the invention has been described in terms of preferred embodiments, other variations which do not depart from the scope of the invention as claimed will become apparent to those skilled in the art.

Examples

1. In a wireless communication system including at least one Access Point (AP) and a plurality of Stations (STAs), a method comprising:

(a) a first STA sending a Direct Link Setup (DLS) request to an AP for setting up a direct communication link to a second STA;

(b) the AP forwarding the DLS request to the second STA;

(c) the second STA sending a response to the AP accepting or rejecting the DLS request;

(d) the AP determining whether to accept the DLS request; and

(e) the AP sends a DLS response to the first STA, whereby the first STA and the second STA may communicate directly with each other over a direct communication link if the DLS request is accepted.

2. The method of embodiment 1 wherein the determination of step (d) is based on the strength of signals exchanged between the first and second STAs.

3. The method of embodiment 1, wherein the determining of step (d) is based on the current load activity of the AP.

4. The method of embodiment 1 wherein the determination of step (d) is based on the capabilities of the first and second STAs.

5. The method of embodiment 1 wherein the determining of step (d) is based on a channel quality over which data packets are exchanged between the first and second STAs.

6. The method of embodiment 5 wherein the channel quality is determined by exchanging packets between the first and second STAs before a DLS is implemented.

7. The method of embodiment 1 wherein the determining of step (d) is based on an interference level of a channel over which data packets are exchanged between the first and second STAs.

8. The method of embodiment 1 wherein the DLS request comprises at least one of: a rate set, capabilities of the first STA, and Medium Access Control (MAC) addresses of the first STA and the second STA.

9. The method of embodiment 1, further comprising:

(f) the AP sending a measurement request to the first STA for measuring a channel state at the first and second STAs;

(g) the first STA sends a response with a measurement result, whereby the AP determines whether to accept the DLS request according to the measurement result.

10. The method of embodiment 1, further comprising:

(f) the first STA sends a message to the AP to search for the second STA before the first STA sends the DLS request to the AP, whereby the first STA sends the DLS request to the AP only if the first STA receives the second STA's related information from the AP.

11. The method of embodiment 1 wherein the first STA includes an optimized rate and channel quality information between the first STA and the second STA in the DLS request.

12. The method of embodiment 11 wherein the information is obtained from a previous transmission between the first STA and the second STA.

13. The method of embodiment 11 wherein the information is obtained by monitoring transmissions from the second STA.

14. The method of embodiment 1 wherein the AP is configured to reject the DLS request if the AP can provide a higher overall performance between the first and second STAs by facilitating transmissions via the AP, rather than allowing direct communication between the first and second STAs.

15. The method of embodiment 1 wherein the AP is configured to reject the DLS request if the quality of the communication link between the first and second STAs is degraded.

16. The method of embodiment 1 wherein the AP is configured to reject the DLS request in order to protect communications between the first and second STAs.

17. The method of embodiment 1 wherein the AP sends a DLS response message to a selected one of the first and second STAs.

18. The method of embodiment 17 wherein the DLS response message includes an action frame for DLS teardown having a timer information field and the selected STA must respond to the AP with a DLS teardown message before the timer expires in order to initiate DLS teardown.

19. The method of embodiment 1 wherein each of the first and second STAs includes a timer and each of the first and second STAs is configured to initiate a DLS teardown procedure performed by the AP before the timer expires.

20. The method as in embodiment 19, wherein the timer is reset in response to receiving a packet.

21. The method of embodiment 1 wherein the first STA sends a measurement packet to the second STA and the AP before performing DLS to improve a data rate and a packet error rate.

22. The method of embodiment 21, wherein the measurement packet is one of: a Channel Quality Indicator (CQI), a Received Signal Strength Indicator (RSSI), or an interference measurement.

23. In a wireless communication system including at least one Access Point (AP) and a plurality of Stations (STAs), a method of peer-to-peer communication, the method comprising:

(a) each STA maintains a database of one-hop STA and two-hop STA, wherein the one-hop STA is one STA capable of monitoring other STAs, and the two-hop STA is associated with the one-hop STA and cannot directly monitor other STAs; and

(b) STAs that desire to communicate with each other send a message to their hop STAs regarding a desired communication between the STAs, whereby the communication between the STAs is uninterrupted by neighboring STA transmissions.

24. The method of embodiment 23, further comprising:

(c) a new STA participating in the system sending a request message to the neighboring STAs;

(d) the existing STAs sending a response with the necessary information to the new STA; and

(e) the new STA uses this information to initiate communications with other STAs.

25. The method of embodiment 24, wherein the information includes at least one of: bandwidth, a frequency band, subcarrier information, multiple-input multiple-output (MIMO) related information, a Received Signal Strength Indicator (RSSI), interference, Medium Access Control (MAC) address, service capability, and other information about the STA sending the response.

26. The method of embodiment 24 wherein the new STA scans a channel and sends the request message to a particular STA.

27. In a wireless communication system including at least one Access Point (AP) and a plurality of Stations (STAs), a method of peer-to-peer communication, the method comprising:

(a) each STA maintaining a database of STAs with which each STA can communicate directly and STAs with which each STA can communicate via an AP;

(b) a first STA sending a request message to the AP to communicate with a second STA;

(c) the AP determining whether to allow communication between the first STA and the second STA directly or through the AP; and

(d) the AP sends a response message to assign a resource to support the communication.

28. The method of embodiment 27 wherein the AP sends the response message to the first STA and the second STA.

29. The method of embodiment 27 wherein the response message is broadcast whereby all other STAs are notified of the resource assignment.

30. The method of embodiment 27 wherein the AP implements a DLS to establish a direct communication link between the first and second STAs.

31. The method of embodiment 30 wherein a DLS is implemented when the first and second STAs communicate on the direct communication link with better channel quality than when the first and second STAs communicate via the AP.

32. A wireless communication system, comprising:

(a) at least one Access Point (AP);

(b) a first Station (STA); and

(c) a second station, wherein (i) the first STA sends a Direct Link Setup (DLS) request to the AP for setting up a direct communication link to a second STA, (ii) the AP forwards the DLS request to the second STA, (iii) the second STA sends a response to the AP, which either accepts or rejects the DLS request, (iv) the AP determines whether to accept the DLS request, and (V) the AP sends a DLS response to the first STA, whereby the first STA and the second STA can communicate directly with each other if the DLS request is accepted.

33. The system of embodiment 32 wherein the decision as to whether to accept the DLS request is based on the strength of signals exchanged between the first and second STAs.

34. The system of embodiment 32 wherein the determination as to whether to accept the DLS request is based on the current load activity of the AP.

35. The system of embodiment 32 wherein the decision as to whether to accept the DLS request is based on the capabilities of the first and second STAs.

36. The system of embodiment 32 wherein the determination as to whether to accept the DLS request is based on the quality of a channel over which data packets are exchanged between the first and second STAs.

37. The system of embodiment 36 wherein the channel quality is determined by exchanging packets between the first and second STAs before a DLS is implemented.

38. The system of embodiment 32 wherein the determination as to whether to accept the DLS request is based on an interference level of a channel over which data packets are exchanged between the first and second STAs.

39. The system of embodiment 32 wherein the DLS request includes at least one of: a rate set, capabilities of the first STA, and Medium Access Control (MAC) addresses of the first STA and the second STA.

40. The system of embodiment 32 wherein the AP sends a measurement request to the first STA to measure a channel condition between the first STA and the second STA, and the first STA sends a response with a measurement result, whereby the AP determines whether to accept the DLS based on the measurement result.

41. The system of embodiment 32 wherein the first STA sends a message to the AP to search for the second STA before the first STA sends the DLS request to the AP, and the first STA sends the DLS request to the AP only when the first STA receives the second STA-related information from the AP.

42. The system of embodiment 32 wherein the first STA includes an optimized rate and channel quality information between the first STA and the second STA in the DLS request.

43. The system of embodiment 42 wherein the information is obtained from a previous transmission between the first STA and the second STA.

44. The system of embodiment 42 wherein the information is obtained by monitoring transmissions from the second STA.

45. The system of embodiment 32 wherein the AP is configured to reject the DLS request if the AP can facilitate transmission between the first and second STAs through the AP to provide a higher overall performance than if direct communication between the first and second STAs were allowed.

46. The system of embodiment 32 wherein the AP is configured to reject the DLS request to secure communications between the first and second STAs.

47. The system of embodiment 32 wherein each of the first and second STAs includes a timer, and each of the first and second STAs is configured to initiate a DLS teardown procedure performed by the AP before the timer expires.

48. The system of embodiment 47 wherein the timer is reset in response to receiving a packet.

49. The system of embodiment 32 wherein the first STA sends a measurement packet to the second STA and the AP before DLS is implemented to improve a data rate and a packet error rate.

50. The system of embodiment 49 wherein the measurement packet is one of: a Channel Quality Indicator (CQI), a Received Signal Strength Indicator (RSSI), or an interference measurement.

51. A method implemented in a wireless communication system including at least one Access Point (AP) and a plurality of Stations (STAs), the method comprising:

(a) the AP sending a Direct Link Setup (DLS) initiation message to a first STA and a second STA for setting up a direct communication link between the first and second STAs;

(b) each of the first and second STAs sending a DLS request message to the AP, each DLS request message indicating whether the DLS initial message is accepted or rejected by the respective STA; and

(c) when the DLS request message indicates that the DLS initial request has been accepted, the AP sends a DLS response message to each of the first STA and the second STAs to initiate a data transmission on a communication link between the first and second STAs.

52. The method of embodiment 51 wherein the DLS initiation message includes an action frame used by the AP to initiate a DLS setup between two STAs.

53. A method as in any embodiments 51-52 wherein the DLS initiation message is configured to allow a STA to respond thereto.

54. The method as in any embodiments 51-53, wherein the DLS response message is configured to allow the AP to initiate a DLS between two STAs.

55. The method of embodiment 51 wherein the DLS initiation message comprises an action frame having a timer information field.

56. The method of embodiment 55 wherein each of the STAs must respond to the AP with a DLS request message before the timer expires to initiate a DLS between the STAs.

Claims

(b) the AP forwarding the DLS request to the second STA;

(d) the AP determining whether to accept the DLS request; and

2. The method of claim 1 wherein the determination of step (d) is based on the strength of signals exchanged between the first and second STAs.

3. The method of claim 1 wherein the determination of step (d) is based on the current load activity of the AP.

4. The method of claim 1 wherein the determination of step (d) is based on the capabilities of the first and second STAs.

5. The method of claim 1 wherein the determination of step (d) is based on a channel quality over which data packets are exchanged between the first and second STAs.

6. The method of claim 5 wherein the channel quality is determined by exchanging packets between the first and second STAs before a DLS is implemented.

7. The method of claim 1 wherein the determination of step (d) is based on an interference level of a channel over which data packets are exchanged between the first and second STAs.

8. The method of claim 1 wherein the DLS request includes at least one of: a rate set, capabilities of the first STA, and Medium Access Control (MAC) addresses of the first STA and the second STA.

9. The method of claim 1, further comprising:

10. The method of claim 1, further comprising:

11. The method of claim 1 wherein the first STA includes an optimized rate and channel quality information between the first STA and the second STA in the DLS request.

12. The method of claim 11 wherein the information is obtained from a previous transmission between the first STA and the second STA.

13. The method of claim 11 wherein the information is obtained by monitoring transmissions from the second STA.

14. The method of claim 1 wherein the AP is configured to deny the DLS request if the AP can provide a higher overall performance between the first and second STAs by facilitating transmissions via the AP than if direct communication between the first and second STAs is allowed.

15. The method of claim 1 wherein the AP is configured to reject the DLS request if the quality of the communication link between the first and second STAs is degraded.

16. The method of claim 1 wherein the AP is configured to reject the DLS request to protect communications between the first and second STAs.

17. The method of claim 1 wherein the AP sends a DLS response message to a selected one of the first and second STAs.

18. The method of claim 17 wherein the DLS response message includes an action frame for DLS teardown having a timer information field, and the selected STA must respond to the AP with a DLS teardown message before the timer expires in order to initiate DLS teardown.

19. The method of claim 1 wherein each of the first and second STAs includes a timer, and each of the first and second STAs is configured to initiate a DLS teardown procedure performed by the AP before the timer expires.

20. The method of claim 19 wherein the timer is reset in response to receiving a packet.

21. The method of claim 1 wherein the first STA sends a measurement packet to the second STA and the AP before DLS is performed to improve a data rate and a packet error rate.

22. The method of claim 21 wherein the measurement packet is one of: a Channel Quality Indicator (CQI), a Received Signal Strength Indicator (RSSI), or an interference measurement.

24. The method of claim 23, further comprising:

25. The method of claim 24, wherein the information includes at least one of: bandwidth, a frequency band, subcarrier information, multiple-input multiple-output (MIMO) related information, a Received Signal Strength Indicator (RSSI), interference, Medium Access Control (MAC) address, service capability, and other information about the STA sending the response.

26. The method of claim 24 wherein the new STA scans a channel and sends the request message to a specific STA.

28. The method of claim 27 wherein the AP sends the response message to the first STA and the second STA.

29. The method of claim 27 wherein the response message is broadcast whereby all other STAs are notified of the resource assignment.

30. The method of claim 27 wherein the AP implements a DLS to establish a direct communication link between the first and second STAs.

31. The method of claim 30 wherein a DLS is implemented when the first and second STAs communicate on the direct communication link with better channel quality than when the first and second STAs communicate via the AP.

32. A wireless communication system, comprising:

(a) at least one Access Point (AP);

(b) a first Station (STA); and

33. The system of claim 32 wherein the decision as to whether to accept the DLS request is based on the strength of signals exchanged between the first and second STAs.

34. The system of claim 32 wherein the determination of whether to accept the DLS request is based on the current load activity of the AP.

35. The system of claim 32 wherein the decision as to whether to accept the DLS request is based on the capabilities of the first and second STAs.

36. The system of claim 32 wherein the determination of whether to accept the DLS request is based on the quality of a channel over which data packets are exchanged between the first and second STAs.

37. The system of claim 36 wherein the channel quality is determined by exchanging packets between the first and second STAs before a DLS is implemented.

38. The system of claim 32 wherein the determination as to whether to accept the DLS request is made on a channel over which data packets are exchanged between the first and second STAs based on an interference level of the channel.

39. The system of claim 32 wherein the DLS request includes at least one of: a rate set, capabilities of the first STA, and Medium Access Control (MAC) addresses of the first STA and the second STA.

40. The system of claim 32 wherein the AP sends a measurement request to the first STA for measuring a channel condition between the first STA and the second STA, and the first STA sends a response with a measurement result, whereby the AP determines whether to accept the DLS based on the measurement result.

41. The system of claim 32 wherein the first STA sends a message to the AP to search for the second STA before the first STA sends the DLS request to the AP, and the first STA sends the DLS request to the AP only when the first STA receives the second STA's related information from the AP.

42. The system of claim 32 wherein the first STA includes an optimized rate and channel quality information between the first STA and the second STA in the DLS request.

43. The system of claim 42 wherein the information is obtained from a previous transmission between the first STA and the second STA.

44. The system of claim 42 wherein the information is obtained by monitoring transmissions from the second STA.

45. The system of claim 32 wherein the AP is configured to reject the DLS request if the AP can provide a higher overall performance between the first and second STAs by facilitating transmission via the AP, rather than allowing direct communication between the first and second STAs.

46. The system of claim 32 wherein the AP is configured to reject the DLS request to secure communications between the first and second STAs.

47. The system of claim 32 wherein each of the first and second STAs includes a timer, and each of the first and second STAs is configured to initiate a DLS teardown procedure performed by the AP before the timer expires.

48. The system of claim 47 wherein the timer is reset in response to receiving a packet.

49. The system of claim 32 wherein the first STA sends a measurement packet to the second STA and the AP before DLS is performed to improve a data rate and a packet error rate.

50. The system of claim 49 wherein the measurement packet is one of: a Channel Quality Indicator (CQI), a Received Signal Strength Indicator (RSSI), or an interference measurement.

52. The method of claim 51 wherein the DLS initiation message includes an action frame used by the AP to initiate a DLS setup between two STAs.

53. The method of claim 51 wherein the DLS initiation message is configured to allow a STA to respond thereto.

54. The method of claim 51 wherein the DLS response message is configured to allow the AP to initiate a DLS between two STAs.

55. The method of claim 51 wherein the DLS initiation message includes an action frame having a timer information field.

56. The method of claim 55 wherein each STAs must respond to the AP with a DLS request message before the timer expires to initiate a DLS between the STAs.