BRPI0713797A2 - system and method for communicating signal transmissions in a local area wireless network (wlan) system - Google Patents

Abstract

SYSTEM AND METHOD FOR COMMUNICATION OF TRANSMISSION OF ORIENTATION SIGNAL IN A WIRELESS LOCAL AREA NETWORK SYSTEM. A method for communicating guidance signal transmissions from a wireless access point (WAP) to a client transceiver on a wireless local area network (WLAN) system (figure 1) includes obtaining a synchronism reference point for the cold free access point. The sector configuration and sector synchronism in the WAP are then determined. A virtual target guidance signal transmission time (TBTT) for the sector of interest served by the WAP is then calculated, as is a channel number for the sector of interest. Finally, the method provides listening in a sector orientation signal from the sector of interest in the virtual TBTT and the calculated channel number.

Description

SYSTEM AND METHOD FOR COMMUNICATION OF GUIDANCE SIGNAL TRANSMISSIONS IN WIRELESS LOCAL AREA NETWORK SYSTEMS

(WLAN) Field of the Invention

The present invention generally relates to a client using a wireless network (AP) access point, and more particularly to access point orientation signal transmissions having directional antennas.

Background

The Institute of Electrical and Electronics Engineers (IEEE) standards define guidance signal transmissions in a variety of ways including transmissions from access points (APs) in an infrastructure mode, from wireless local area networks. (WLANs) and from clients in an ad hoc mode. Those skilled in the art will recognize that in the WLAN environment, the "client" is the mobile station or user who uses the AP to establish wireless communications with other users or devices. In addition, those skilled in the art will recognize that the target guidance signal transmission time (TBTT) in a WLAN is governed by a common network timer called the "sync sync function" or TSF timer and guidance signal interval. These two information elements, which are carried in guidance signals and other management messages, enable a unique TBTT during each guidance signal interval that is common to the AP and all liquids served by that AP. TBTT represents only one target or expected transmission time for guidance signals. TBTT represents only one target or expected transmission time for guidance signals. However, in practice, guidance signal transmission may be delayed due to various factors such as interference, charging or the like.

Although IEEE standards govern system architecture, the guidance signal transmission methodology by sectored APs is not well defined. Those skilled in the art will recognize that a sectored AP is an AP with multiple directional antennas forming multiple sectors. As described here, the terms "sectors" and "directional antennas" are used interchangeably. Also, features on a network with multiple levels of APs and / or clients are even less defined by the standard.

One issue that requires resolution in networks such as these involves a "neighbor" discovery process on a client that is used to identify and discover sectors of the same AP. This discovery process is not defined by current standards. Moreover, since service AP sector guidance signal transmission times, where the service AP is the AP to which the customer is associated, are not known to a customer or defined by the standards, intelligent programming traffic to and from multiple sectors (for site diversity and connection transfer before efficient disconnection) cannot be performed. Efficient scheduling of traffic reception based on traffic notification pending guidance signals is also not possible. In other words, the customer may not be able to tell from which antenna and at which time interval to hear traffic without a high degree of signaling processing time. FIG. 1 of the prior art illustrates such a wireless network 100 where wireless access point 101 utilizes directional antennas defining sectors 103, 105, 107, and 109. If a client 111 were transitioning from sector 109 to sector 103 , it would be important for client 111 to receive guidance signal traffic from sector 103 of access point 101 in a timely manner.

Hence, client 111 may not be able to program uplink traffic efficiently since it cannot know when its current sector is sending its guidance signal or actively receiving traffic. This will result in unnecessary retransmissions and power drainage on a portable client. These problems multiply in complexity when different antennas operate at different frequencies, requiring improved methods of propagating guidance signals over a wireless local area network.

Brief Description of the Figures The associated figures, in which reference numerals

The same references refer to identical or functionally similar elements throughout the various separate views and which together with the detailed description below are incorporated into and form part of the descriptive report, serve to further illustrate various embodiments and to explain the various principles and advantages. , all in accordance with the present invention.

FIG. 1 is an illustration of a prior art wireless network including an access point with an intersector transfer from one directional antenna to another at the same AP.

FIG. 2 illustrates a timing diagram for a sector orientation signal transmission by an access point, where the sectors are on the same channel.

FIG. 3 illustrates a timing diagram for a sector orientation signal transmission by an access point, where the sectors are in different channels.

FIG. 4 illustrates a synchronization diagram for a sector orientation signal transmission by an access point, where the sectors use a hybrid channel plan.

FIG. 5 is a flowchart illustrating a customer's industry discovery process.

FIG. 6 is a flowchart illustrating an intersector transfer between sectors of the same access point.

Skilled technicians will appreciate that the elements in the figures are illustrated for simplicity and clarity and not necessarily drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help improve understanding of embodiments of the present invention.

Detailed Description

Prior to the detailed description of embodiments in accordance with the present invention, it should be noted that the embodiments reside primarily in combinations of method steps and apparatus components related to the transmission and reception of guidance signals in a local area network. Therefore, the apparatus components and method steps have been represented where appropriate by conventional symbols in the drawings, showing those specific details that are pertinent to the understanding of the embodiments of the present invention, so as not to obscure the disclosure in detail that will be readily apparent to those of ordinary skill in the art having the benefit of the description herein.

In this document, relational terms such as first and second, top and bottom, and the like may be used solely to distinguish one entity or action from another entity or action, without necessarily requiring or implying any such real relationship or order between them. entities or actions. The terms "comprising", "comprising" or any variation thereof are intended to cover a non-exclusive inclusion, so that a process, method, article or apparatus comprising a list of elements does not include only those elements, but may include other elements not expressly listed or inherent in such process, method, article or apparatus. An element preceded by "comprises ... one" does not preclude, without further restriction, the existence of additional identical elements in the method, method, article or apparatus comprising the element.

It will be appreciated that embodiments of the invention described herein may utilize one or more conventional processors and unique stored program instructions that control one or more processors for implementation, along with certain non-processor circuits, some, most or all of the transmission functions. and receiving guidance signals in the WLAN described herein. Nonprocessor circuits may include, but are not limited to, a radio receiver, radio transmitter, signal controllers, clock circuits, power supply circuits, and user input devices. As such, these functions can be interpreted as steps of a method for performing the transmission and / or reception of guidance signals in a WLAN. Alternatively, some or all of the functions could be implemented by a state machine that did not have stored program instructions, or in one or more application-specific integrated circuits (ASICs), where each function or some combinations of certain functions are implemented as a custom logic. Obviously, a combination of both approaches could be used. Thus methods and means for these functions have been described herein. Still, it is expected that someone of common knowledge, notwithstanding possibly significant effort and motivated by many design choices, eg available time, current technology and economic considerations, when guided by the concepts and principles shown here, will readily be able to generate these software instructions and these programs and ICs with minimal experimentation.

As described in FIGs. 2 to 6, the present invention comprises various embodiments whose solution includes components that control AP behavior and Client behavior, for facilitating sector discovery and intersector transfer on the client. These components include 1) an AP behavior in which the AP transmits guidance signals in its different sectors in a predetermined manner and announces the details to clients; and 2) customer behavior, which utilizes the assistance provided by the AP for efficient sector discovery and intersectoral transfer. This allows the client to hear announcements made by the AP with reference to their other sectors and use the information to discover their own "reach" or ability to communicate with these sectors.

With respect to AP behavior and a broadcast and sector guidance signal announcements, the responsibility of the AP is to transmit guidance signals in each of its sectors in predictable times. The AP then announces to customers information regarding sector orientation signal transmission times and channel numbers. Sector antennas (not shown) can operate on the same channel, on different channels or in a hybrid combination (ie some on one channel and some on another channel). The following description illustrates the guidance signal transmission method for each of these three cases and also the advertising method that the AP can use to inform its clients about sector guidance signal propagation.

FIG. 2 illustrates a sector orientation signal transmission timeline in which all AP sectors operate on the same channel. In the illustration, D1, D2, D3, D4 represent the various AP sector directions, while Cl represents a single channel. Thus, in this example, sector antennas are not on the same channel (Cl); Sector guidance signals are transmitted on the respective directional antennas (D1 to D4) individually in a sequence starting at a target orientation signal transmission time (TBTT) and separated by an antenna switching time. An antenna switching time is minimally defined as the delay incurred during a changeover from one directional antenna to another (or alternatively a changeover from the same directional antenna from one direction to another). In one embodiment, the antenna switching time may consider all delays (eg, hardware element switching, software element switching, etc.) incurred by the AP between a sector orientation signal transmission on a sector and being ready to transmit a sector guidance signal in another sector. In one embodiment, one or more directional antennas (D1 to D4) are the same physical antenna, which switches directions to serve four sectors. Hence, each of the four sectors uses orientation signals ({Dl, Cl}, {D2, Cl}, {D3, Cl}, {D4, Cl}), each transmitted in their respective direction (one on each directional antenna rear to rear) for each respective sector. These guidance signals are separated in time only by the time used for switching the AP antenna from one sector to another. The same TBTT or TSF timer is used by the AP to initiate orientation signal propagation. The same TBTT or TSF timer is used by the AP for orientation propagation initiation. In other words, only a single differentiated value of TBTT is generated and used by the AP for guidance signal transmission and clients for guidance signal reception. FIG. 2 illustrates sector orientation signal D1 beginning at TBTT, followed by sector orientation signals D2, D3, and D4. It will be apparent to those skilled in the art that it is possible to change the transmission order of the "working" sector guidance signals. This allows customers in all industries to have a reasonable guidance signal waiting period, which improves power savings for handheld devices.

FIG. 3 illustrates an alternative embodiment to that shown in FIG. 2, where the orientation signal transmissions are separated by non-negligible time shifts, where the sectors use different channels (Cl, C2, C3, C4) for uniformity and for other reasons. The main difference in this embodiment, as opposed to having each sector in the same channel, as shown in FIG. 2 is that a non-negligible antenna and frequency or channel switching delay is incurred during a switch between sectors. Therefore, all antenna and channel switching will carry some additional system processing time. In this case, rear-to-rear orientation signal transmissions may cause unnecessary switching processing time. Thus, the sector orientation signals are spaced in time by some non-negligible "Interchannel Shift", which is much larger than the antenna switching time plus channel switching time. Sector orientation signals are transmitted on the respective directional antennas (D1, D2, D3, D4) and channels (Cl, C2, C3, C4), separated by a not insignificant offset, "Intercanal Displacement", which is very greater than antenna and channel switching time. In this embodiment, there are four sectors using four channels, where four orientation signals are transmitted using a directional antenna on their channel. These orientation signals are separated by "Intercanal Shift". Since sector guidance signals are transmitted at different time intervals, each sector needs its own TSF and TBTT Timer. Therefore, there are four virtual TBTTs (one for each sector) in an AP. as seen in FIG. 3, each sector orientation signal is transmitted in its own virtual TBTT, specifically, TBTT_C1, TBTT_C2, TBTT_C3 and TBTT_C4. Note that the four sectors and four channels are just an example. In another embodiment of this invention, the channels C1, C2, C3, C4 are one and the same. In another embodiment of this invention, there could be "n" channels and "m" antennas, with "n" smaller than "m" and still use the scheme described above using "m" virtual TBTTs.

In yet another embodiment, FIG. 4 illustrates a sector orientation signal transmission wherein each of the sectors operates as a hybrid of that shown in FIG. 2 and FIG. 3. Thus, sectors in the same channel are linked to a single virtual TBTT and are transmitted rear to rear on that virtual TBTT. However, there are "m" virtual TBTTs, where "m" is the total number of channels across all sectors of the given AP. Virtual TBTTs are spaced by non-negligible "Intercanal Shift". In this example, sectors D1 and D2 use channel Cl, and sectors D3 and D4 use channel C2. Virtual TBTTs for guidance signals for D1 and D3 are separated by intercanal shift. Similarly, a new sector D5 is designed for use of channel C3 and sectors D6 and D7 are used with channel C4. As seen in FIG. 4, each channel has its own unique virtual TBTT, specifically TBTT_C1, TBTT_C2, TBTT_C3, and TBTT_C4. In another embodiment of this invention, the channels C1, C2, C3, C4 are one and the same. In other embodiments of this invention, any combination of channels could be reused with the appropriate array of antennas and channels.

In operation, the AP needs to announce some sector-specific information to clients to facilitate rapid sector discovery and intersector transfer. This information may include such information as sector number, virtual TSF timing (used for calculation of virtual TBTTs) and number of channels. Specifically, the customer can use a sector number to differentiate across sectors to determine their membership. Those skilled in the art will recognize that sector numbers can be performed within management frames such as guidance signals / probe responses / association responses and the like. Thus, the AP can sweat many known techniques for such an ad.

As cited herein, the TSF timer is carried on guidance signals and other management messages, and is used for the calculation of a single TBTT in a guidance signal range corresponding to a single AP, as well as all clients associated with a single AP. him. This, in turn, helps the client predict their TBTT from their AP. in the embodiment shown in FIG. 2, this methodology is reused since a single TBTT in a guidance signal range is required. However, in many subsequent embodiments of the present invention, there is a need for support of multiple virtual TBTTs in the same guidance signal range to support efficient guidance signal use by a multi-sector AP. Additionally, customers need to be able to predict virtual TBTT from at least one industry to which they are associated. In order to determine this location, virtual TSF timer values are transmitted in the guidance signals and probe responses of each respective sector. These values may override the TSF timer value that may be ported in another proprietary field, or may be inferred from the sector information element (IE) as defined herein.

Virtual TSF timer values are calculated using the equation:

TSF_timerCi = Master_TSF_Timer + (i - 1) * Offset where i = the channel number, Master_TSF_Timer is the main or actual TSF timer running (or being continuously recorded) on the AP; and Offset is Intercanal Offset.

It will be apparent to those skilled in the art that the equation assumes one virtual TSF timer per channel, but this can be generalized to include one virtual TSF timer per sector or sector group by interpreting the value of "i" and Offset from conforming mode.

In addition, a new information element (referred to as a sector information element here) may be added to carry all information regarding other sector guidance signals for facilitating sector discovery in customers. This can be accomplished by the guidance signal / association response / probe response. Sector IE may include one or more fields shown in Table 1, with respect to FIG. 4. However, those skilled in the art will recognize that virtual TBTTs may be sector based (not channel based), where this information may be generalized in terms of sectors or any other alternative.

0 "Number of Channels" is the value of the total number of channels used by the sectors of the given AP. For example, in FIG. 4, there are four channels used. "Channel Number [i]" is the channel number for which the virtual TSF timer is represented by TSF_timerCi. It should be noted that the virtual TBTT values are in ascending order of i (i = 1, 2, ... n, where n = number of channels). For example, in FIG. 4, there are four channels used, that is, η = 4. Also, Channel numbers Cl, C2, C3, C4 are 1, 2, 3, 4, respectively. For example, Channel Number [2] is 2. "Number of Sectors [i]" is the number of sectors in "Channel Number]". For example, in FIG. 4, the number of sectors in channel C3 is 1. Therefore, Channel Number [3] and Number of Sectors [3] = 1. 0 "Offset" is the Interchannel Offset, as shown in FIG. 4. Table 1 illustrates an example of Sector IE fields.

Table 1. Example values of sector IE fields

<table> table see original document page 14 </column> </row> <table> <table> table see original document page 15 </column> </row> <table> With respect to customer behavior, the responsibility of the The client is to discover reachable sectors of his own AP or those of his neighboring APs in order to determine the most appropriate sector for transfer. As cited here, AP assistance is provided to assist with customer sector discovery. In addition, the customer also has a responsibility in sector discovery. In case virtual TBTTs are implemented, the customer only needs to use the virtual TBTT from their service sector for synchronization purposes. This is accomplished by using a given virtual TSF timer to calculate its timing information. As should be obvious to those skilled in the art, all customer-performed timing calculations as described in the following sections can be done with respect to the customer service sector virtual TSF timer or its service AP.

As a sector orientation signal reception in which sectors use the same channel and the orientation signal transmission methodology follows FIG. 2 (ie with a single TBTT), the customer calculates TBTT based on their own sector guidance signal. At TBTT, the customer waits for guidance signals from their own sector and other sectors of their service AP. The sector orientation signals received indicate the achievable sectors. In neighboring AP sectors where the sectors use the same channel and the guidance signal transmission methodology follows FIG. 2, the client calculates the TBTT of his neighbor AP using procedures well known in the art, such as neighbor reports from the service AP, active scan, passive scan, etc. During a neighbor discovery, the client waits for guidance signals from neighboring AP sectors starting from the neighboring given TBTT. The sector guidance signals received indicate the "reachable" sectors, that is, those with which you can communicate. Those skilled in the art will recognize that a legacy client may receive multiple rear-to-rear guidance signals if the customer is in an overlap sector region. However, each of the guidance signals will carry the updated mapping value to the same TBTT value and thus the client will use the latest available information.

In situations where service AP sectors are on different channels or the guidance signal transmission methodology follows that shown in FIG. 3 or FIG. 4 (ie multiple virtual TBTTs per guidance signal range), the client calculates its virtual TBTT based on its own sector guidance signal. In addition, the customer learns the other virtual TBTTs from their service AP based on the information announced by the AP. During an industry discovery, it waits for guidance signals from other sectors of its service AP on their respective virtual TBTTs and channel numbers. The sector guidance signals received indicate the "reachable" sectors with which the customer can communicate.

In neighboring AP sectors, where neighboring AP sectors are on different channels or the guidance signal transmission methodology follows that shown in FIG. 3 or FIG. 4, Client calculates at least one virtual TBTT and other related information from its neighbor AP using a neighbor report, active scan, passive scan or the like. During a neighbor discovery, the client waits for guidance signals from neighboring AP sectors at their respective virtual TBTTs and channel number. The sector guidance signals received indicate those sectors which are "reachable", ie sectors in which communication is possible. Legacy clients will only receive an orientation signal on the channel on which they are operating with the virtual TSF timer to allow them to calculate the virtual TBTT value. Thus legacy clients can operate as usual.

In situations where sectors serving as the service AP are in the hybrid sector channel plan or the guidance signal transmission methodology follows that shown in FIG. 4, Customer calculates their virtual TBTT based on their own sector guidance signal. Additionally, he learns the other virtual TBTTs and sectors by virtual TBTT from his service AP based on the information announced by the AP. During a sector discovery, the customer waits for guidance signals from other sectors of their service AP on their virtual TBTTs and channel numbers. Sector guidance signals received 25 indicate achievable sectors.

For neighboring AP sectors, where neighboring AP sectors are in the hybrid sector channel plan or the guidance signal transmission methodology follows that shown in FIG. 4, the client calculates at least one virtual TBTT and other related information from its neighboring AP through known techniques, such as neighbor reporting, active scanning, passive scanning or the like. During a neighbor discovery, it waits for guidance signals from neighboring AP sectors on their respective virtual TBTTs and channel number. The sector orientation signals received indicate the achievable sectors. As noted here, a legacy client can again receive multiple sector guidance signals on its own channel. As mentioned earlier, this will have no impact on your operation.

FIG. 5 illustrates the method 500 used by a client for AP sector discovery, where the AP can be defined as the client service AP or a neighboring AP. As shown here, the process is started at 501 and a reference sync for the AP is obtained at 502, where the reference sync for the AP is the virtual TBTT or the virtual TSF timer associated with at least one AP sector. In case the AP is the service AP, the reference point can be the virtual TBTT or the service sector virtual TSF timer. When the AP is a neighboring AP, the client can obtain reference sync from its neighboring AP using procedures well known in the art, such as neighboring reports from the service AP, active scan, passive scan, etc.

The customer learns the AP sector configuration and sector orientation signal timing at 503. The AP sector configuration includes at least one of the number of channels, number of sectors, and number of sectors per channel used in the AP The sector guidance signal sync may include at least one of the virtual TSF timer value for a sector, an interchannel offset and the guidance signal interval. In one embodiment, the client learns the relevant information, that is, the number of channels and the number of sectors of the given AP, and the sector guidance signal timing of each sector guidance signal through its sector-specific announcement. Service AP or AP according to the sector-specific announcement transmitted by the APs as described above. In another mode, this information is preconfigured on the client.

When it is time for the sector discovery on the customer, this determination is made at 505 and once a time has elapsed the customer then calculates the estimated virtual TBTTs associated with each sector of interest at 506. The customer calculates the virtual TBTT estimated from a given sector based on at least one of the number of channels learned, the number of sectors per channel and the sector orientation signal sync from 503, and the reference sync for the AP as obtained at 502 During this step, the customer can also calculate the channel number of each sector of interest.

The client then intelligently listens to the sector guidance signal on the virtual TBTT calculated at 507, as well as the channel number learned for each sector of interest. Once the relevant information, such as the sector guidance signal, is received or the process expires, the process is completed by 509.

An intersector transfer is defined as a transfer of client traffic flows between sectors of the same AP. In other words, after a successful intersector transfer, the client downlink traffic stream will be sent through the new sector, as opposed to the old sector. For an intersector transfer, since the client is already associated with the AP, an intersector transfer can occur in an implicit manner, so that no association / authentication is required. If a client-initiated access scheme is employed, then the client can transmit a trigger frame to the AP to receive or transmit its traffic when the new sector antenna is active. The AP on receiving this trigger frame through its given sector antenna implicitly associates this client with the new sector. If the channel access scheme employed is not client initiated, then the customer may need to transmit a dummy frame or data frame (if available) to the AP when the new sector antenna is active to obtain the transfer. implicit intersector. For pure contention-based schemes (Distributed Coordination Function (DCF), Enhanced Distributed Channel Access (EDCA), or the like), the client can transmit this frame as soon as he can (using contention-based procedures). For pure interrogation / programming based schemes (Point Coordination Function (PCF), Hybrid Coordination Function Controlled Channel Access (HCCA) or similar), the client will need to wait until the channel is available to send this frame (using procedures based on contention).

FIG. 6 illustrates the method by which an intersector transfer, that is, a transfer between sectors of the same AP occurs at 600. This process starts at 601 and the client learns when the new sector antenna is active on the AP at 603. The new antenna The sector antenna here refers to the antenna associated with the sector to which the customer is trying to transfer. If the new sector antenna is active at 605, a determination will be made as to whether the customer is in a 607 contention period. The contention period here refers to a time period determined by the AP during which any client or AP can initiate frame transmission after observing well-known channel access rules such as random withdrawal, deference, etc. If in a contention period, then the client transmits a data frame or a trigger frame toward the AP using contention-based access methods well known in the art, such as Distributed Coordination Function (DCF), Access Access. Enhanced Distributed Channel (EDCA), and so on. After that, the process is completed in 611.

Those skilled in the art will recognize that the invention described herein offers several advantages with respect to neighbor discovery and cross-sectoral transfer in which a) customers can identify and discover sectors of the same AP based on guidance signals received from these sectors. ; and b) clients can predict the orientation signal timing and channel number of the various sectors of an AP. Therefore, the customer spends less time discovering neighbor to sectors, increasing transfer efficiency and power savings.

This invention also facilitates traffic bidding or n-broadcasting for site diversity and connection transfer prior to efficient disconnection. In other words, the same package or different packages from multiple sectors can be sent to a client to facilitate flexible transfers or provide site diversity. In such a case, the guidance signals from each sector involved will indicate the presence of traffic through the indication maps. Non-overlapping sector guidance signals with predictable guidance signal transmission times will allow the customer to look at all involved sector guidance signals and determine when to retrieve packets from each of these sectors. Additionally, this method provides the client with a unique AP association / authentication process, rather than an AP sector association / authentication process. Thus, a diversity of sites can be enabled seamlessly without the need for additional association / authentication processes. Finally, the customer can use the time during which unreachable sectors of the service AP are active to communicate with other directly reachable customers.

Thus, the present invention provides a new method for propagating orientation signals through various factors of the same AP. Fields are used to provide information such as sector number, virtual TSF timers, and sector IE for differentiating guidance signals from various sectors. This method allows the AP to advertise sector-specific information to aid in sector discovery and an intersector transfer on the client. The present method allows the creation of multiple virtual TBTTs per orientation signal range and sector discovery and intersector transfer.

In the foregoing report, specific embodiments of the present invention have been described. However, one of ordinary skill in the art appreciates that various modifications and changes may be made without departing from the scope of the present invention as set forth in the claims below. Accordingly, the specification and figures should be considered in an illustrative rather than restrictive sense, and it is intended that all such modifications be included within the scope of the present invention. The benefits, advantages, solutions to problems, and any elements that could cause any benefit, advantage or solution to occur or become more pronounced should not be construed as a critical, required or essential feature or element of any or all of them. the claims. The invention is defined solely by the appended claims including any amendments made pending this application and their equivalents to those claims as issued.

Claims (10)

Method for communicating wireless access point (WAP) guidance signal transmissions with a plurality of sectors by a client transceiver in a wireless local area network (WLAN) system, characterized in that it comprises the steps of: obtaining a reference sync for WAP; determining a WAP sector configuration; determining a WAP sector orientation signal timing; determine if the customer is in a time period for sector discovery; calculate a virtual target orientation signal (TBTT) transmission time for a sector of interest; and hear the WAP sector guidance signal in the virtual TBTT calculated by the sector of interest. Method for communicating orientation signal transmissions according to claim 1, characterized in that the calculation step further comprises the step of: determining a channel number for a sector of interest. Method for communicating guidance signal transmissions according to claim 1, further comprising the step of: synchronizing the client transceiver based on the calculated virtual TBTT. 4 Method for communicating an operating sector to a client transceiver in a wireless local area network (WLAN) system, comprising the steps of: receiving at least one advertisement from a wireless access point (WAP) ); determine a WAP sector configuration from at least one ad; determine sector orientation signal timing from at least one ad; determine a channel number for a sector of interest served by WAP; calculate a virtual target orientation signal (TBTT) transmission time for the sector of interest served by WAP; and hearing a sector guidance signal from the sector of interest at the virtual target guidance signal transmission time (TBTT) and the determined channel number. Method for communicating an operating sector to a client transceiver according to claim 4, further comprising the steps of: receiving the sector orientation signal from the sector of interest. Method for communicating an operating sector to a client transceiver according to claim 4, characterized in that the WAP uses at least one directional antenna. Method for communicating an operating sector to a client transceiver according to claim 4, characterized in that it comprises the step of: synchronizing the client transceiver to WAP based on the target orientation signal transmission time ( TBTT) for the industry of interest. Method for communicating an operating sector to a client transceiver according to claim 6, characterized in that the synchronization is performed using a virtual synchronization synchronization function (TSF) timer. Method for communicating an operating sector to a client transceiver according to claim 4, characterized in that the WAP sector configuration includes at least one of the number of channels, the number of sectors and the number of sectors on each channel used in WAP. Method for communicating an operating sector to a client transceiver according to claim 4, characterized in that the sector guidance signal sync may include at least one of the sync sync function timer value. (TSF) for a sector, an interchannel offset, and an orientation signal range.