Method and system for an AD HOC wireless network with master control of network parameters

Aspects of a system for an ad hoc wireless network with master control of network parameters may include one or more circuits that enable generation of a beacon frame at a supervisory WLAN station wherein the generated beacon frame contains a supervisory role indication. The supervisory role indication enables the supervisory WLAN station to establish timing synchronization and network parameters that are utilized by a plurality of WLAN stations utilized for communicating within a wireless network. Aspects of the system may also include a WLAN station that enables communication via a wireless local area network by utilizing a timestamp value and network parameter values retrieved from a received beacon frame based on the presence of a supervisory role indication within the received beacon frame.

FIELD OF THE INVENTION

Certain embodiments of the invention relate to communication networks. More specifically, certain embodiments of the invention relate to a method and system for an ad hoc wireless network with master control of network parameters.

BACKGROUND OF THE INVENTION

IEEE 802.11 describes a communication architecture, which may enable computing devices to communicate via wireless local area networks (WLANs). One of the building blocks for the WLAN is the basic service set (BSS). A BSS may comprise a plurality of computing devices, or stations (STA), which may communicate wirelessly via one or more RF channels within a coverage area. The span of a coverage area may be determined based on the distance over which a source STA may transmit data via an RF channel, which may be received by a destination STA.

An independent BSS (IBSS) refers to a BSS, which comprises a set of STAs, which may communicate with each over within the coverage area for the BSS. The IBSS is identified by a BSS identifier (BSSID) and a service set identifier (SSID). In an IBSS each STA may engage in direct communication with any of the other STAs within the IBSS. An IBSS may be referred to as an ad hoc network.

To facilitate communication within the IBSS, each STA may negotiate a set of network parameters to utilize when communicating with other STAs in the IBSS. These network parameters may include frequency spectrum management for RF channel assignment, determination of supported data rates and quality of service (QoS) parameters, for example. Each STA also attempts to synchronize its operations to a clock source, which is common to the STAs within the IBSS.

The negotiation of network parameters and timing synchronization among the STAB typically involves the exchange of beacon frames. At various time instants, one or more STAB within the IBSS may transmit a beacon frame. A transmitted beacon frame may be received by each of the other STAB within the IBSS. The beacon frame may contain information elements, which specify a set of network parameters and enable timing synchronization among the STAB. Each transmitted beacon frame contains a timestamp value, which is determined based on a timing synchronization function (TSF) executing within the STA that transmitted the beacon frame.

Since an STA may receive a plurality of beacon frames within a time interval, referred to as a nominal beacon window, the receiving STA determines which one, if any, of the received beacon frames is to be adopted. Upon receiving a beacon frame, the receiving STA compares the timestamp value contained within the received beacon frame, with a time value generated by the TSF. When the received timestamp value is greater than the time value generated by the TSF, the TSF time value is set to a value equal to the received timestamp value. In addition, the STA adopts the network parameters contained within the beacon frame. In this regard, the receiving STA time synchronizes to the TSF clock of the STA, which transmitted the beacon frame. In addition, the receiving STA will utilize network parameters contained within the beacon frame when communicating with other STAB within the IBSS.

When the received timestamp value is less than or equal to the time value generated by the TSF, the STA adopts neither the timestamp value or the network parameters contained within the received beacon frame. In this regard, the receiving STA determines to neither time synchronize to the STA, which transmitted the beacon frame, or to utilize network parameters contained within the beacon frame when communicating with other STAs within the BSS.

BRIEF SUMMARY OF THE INVENTION

A method and system for an ad hoc wireless network with master control of network parameters, substantially as shown in and/or described in connection with at least one of the figures, as set forth more completely in the claims.

DETAILED DESCRIPTION OF THE INVENTION

Certain embodiments of the invention may be found in a method and system for an ad hoc wireless network with master control of network parameters. Various embodiments of the invention comprise a method and a system by which a selected wireless station (STA), among a plurality of STAs in an independent basic service set) IBSS, may determine the network parameters utilized by each of the STAs within the IBSS. In addition, each of the STAs may time synchronize to the time values generated by the time synchronization function (TSF) executing within the selected STA. Various embodiments of the invention comprise a method by which the selected STA may be determined among the plurality of STAs within the IBSS.

FIG. 1is a block diagram of an exemplary system for wireless data communication, which may be utilized in an embodiment of the invention. Referring toFIG. 1, there is shown an IBSS102. The IBSS102comprises a WLAN station STA_A112, a STA_B114and a STA_C116. The STA_A112may communicate with the STA_B114via the RF channel124, the STA_A112may communicate with the STA_C116via the RF channel122and the STA_B114may communicate with the STA_C116via the RF channel126.

At any given time, each of the STAs may utilize a set of network parameters when communicating with other STAs within the IBSS102. The timing for communication events may be determined based on a timing value generated by the TSF executing at the STA. For example, at a given time instant to, the STA_A112may utilize a set of network parameters, NP_A(t0), the STA_B114may utilize a set of network parameters, NP_B(t0) and the STA_C116may utilize a set of network parameters, NP_C(t0). When the time instant to corresponds to a target beacon transmission time (TBTT), the time instant may mark the beginning of a time interval, referred to as a nominal beacon window, during which individual STAs may transmit beacon frames to other STAs within the IBSS. In various embodiments of the invention, the nominal beacon window length, BeaconWindowLength, may be represented as shown in the following equation:
BeaconWindowLength=2·aCWmin*aSlotTime  [1]
where aCWmin refers to the lower bound on the upper end of the range from which a random number is selected for use in randomizing the start times of transmission attempts by STA in order to reduce the probability of a collision within a network where distributed medium access is employed and aSlotTime refers to a time duration, which may be sufficient to detect data transmitted via a wireless communication medium at a receiving STA.

Each STA within the IBSS may randomly select a time duration from the range of values between ZERO and the BeaconWindowLength time interval and waits for a duration of medium IDLE time to pass which is equal to that randomly selected value before transmitting a beacon frame. For example, assuming an idle medium, the STA_A112may transmit a beacon frame at a time instant t1, which meets the following criteria:
t0≦t1≦t0+BeaconWindowLength  [2]
The beacon frame transmitted by the STA_A112, BF_A(NP_A(t0),t1), may comprise the set of network parameters NP_A(t0) and a timestamp value equal to t1, where the timestamp value may be based on a value, TSF(A)_val, generated by the TSF executing at the STA_A112.

The STA_B114may receive the beacon frame BF_A(NP_A(t0),t1) via the RF channel124. The STA114may compare the timestamp value of the received beacon frame, t1, with the TSF(B)_value, TSF(B)_val, generated by the TSF executing at the STA_B114. For purposes of exemplary exposition, the following condition may be assumed:
TSF(B)_val<t1[3]
Under the conditions set forth in equation [3], the STA_B may adopt the network parameters and timestamp value from the beacon frame BF_A(NP_A(t0),t1). In this regard, after adopting the parameters contained within the received beacon frame BF_A(NP_A(t0),t1) at STA_B114:
TSF_val(B)=t1[4a]
NP—B(t1)=NP—A(t0)  [4b]

The STA_C116may receive the beacon frame BF_A(NP_A(t0),t1) via the RF channel122. The STA116may compare the timestamp value of the received beacon frame, t1, with the TSF(C) value, TSF(C)_val, generated by the TSF executing at the STA_C116. For purposes of exemplary exposition, the following condition may be assumed:
TSF(B)_val>t1[5]
Under the conditions set forth in equation [5], the STA_C may not adopt the network parameters and timestamp value from the beacon frame BF_A(NP_A(t0),t1). In this regard, after receiving the beacon frame BF_A(NP_A(t0),t1) at STA_C116:
TSF_val(B)=t2[6a]
NP—C(t2)=NP—C(t0)  [6b]
where t2may represent the current TSF(C) value.

As presented in the exemplary discussion above, the TSF(B) at STA_B114may be time synchronized to the TSF(A) at STA_A112, while the TSF(C) at STA_C116may not be time synchronized to either STA_A112or STA_B114. Furthermore, the STA_A112and STA_B114may communicate within the IBSS102utilizing a common set of network parameters NP_A(t0), the STA_C116may attempt to communicate with STA_A112and/or STA_B114while utilizing a different set of network parameters NP_C(t0).

In various embodiments of the invention, the STAs within an IBSS102may adopt supervisory and subordinates roles. In this aspect of the invention, one of the STAs, for example STA112, may be configured to be the supervisory STA, while the other STAs, for example STA_B114and STA_C116, may be configured to be subordinate STAs.

In an exemplary embodiment of the invention, the supervisory STA_A112may compute a time increment value, TSF_inc, which may be added to the current value TSF_val(A). In this regard, TSF_val(A) may be represented as shown in the following equation:
TSF_val_mod(A)=TSF_val(A)+TSF_inc  [7]
The STA_A112may then transmit a beacon frame, which comprises the modified time value TSF_val_mod(A)=tmodand the current set of network parameters NP_A(tmod). The STA_A112then modifies its own TSF_val based on the TSF_val_mod value.

In various embodiments of the invention, the STA_B114may receive the beacon frame BF_A(NP_A(tmod),tmod) at a receive time tR114, as determined by the TSF(B) at STA_B114, where the value of the receive time tR114meets the following condition:
tmod>tR114[8]
Under the condition set forth in equation [8], the STA_B114may adopt the network parameters and timestamp value from the beacon frame BF_A(NP_A(tmod),tmod). In this aspect of the invention, after adopting the parameters contained within the received beacon frame BF_A(NP_A(tmod),tmod) at STA_B114:
TSF_val(B)=tmod[9a]
NP—B(tmod)=NP—A(tmod)  [9b]

In addition, the STA_C116may receive the beacon frame BF_A(NP_A(tmod),tmod) at a receive time tR116, as determined by the TSF(C) at STA_C116, where the value of the receive time tR116meets the following condition:
tmod>tR116[10]
Under the condition set forth in equation [10], the STA_C116may adopt the network parameters and timestamp value from the beacon frame BF_A(NP_A(tmod),tmod). In this aspect of the invention, after adopting the parameters contained within the received beacon frame BF_A(NP_A(tmod),tmod) at STA_C116:
TSF_val(C)=tmod[11a]
NP—C(tmod)=NP—A(tmod)  [11b]

Various embodiments of the invention comprise a method and system by which a STA_A112may be selected as a supervisory STA within an IBSS102. The supervisory STA_A112may generate a modified time value, TSF_val mod(A), based on a current TSF value, TSF_val(A), and a computed time increment value TSF_inc. The modified time value may be utilized as a timestamp value within beacon frames transmitted by the supervisory STA_A112. The modified time value may enable other stations within the IBSS102, STA_B114and STA_C116, to time synchronize to the supervisory STA_A112. In addition, the other STAs within the IBSS102, STA_B114and STA_C116, may adopt the set of network parameters generated by the supervisory STA_A112. In this aspect of the invention, each of the STAs within the IBSS102may communicate with other STAs by utilizing a consistent set of network parameters.

In various embodiments of the invention, the value of the computed time increment may be determined based on the estimated accuracy with which the TSF value is generated at any given STA relative to a determined nominal TSF value. In an exemplary embodiment of the invention, the current actual TSF value at a STA, tact, may vary from the current nominal TSF value, tnom, by an amount less than Δtmax. Thus, the minimum actual TSF value at a STA within the IBSS102, min(tact), may be represented as shown in the following equation:
min(tact)>tmin−Δtmin[12a]
the value presented in equation [12a] may occur at a STA in which the TSF comprises a “slow” system clock. The maximum actual TSF value at a STA, max(tact), may be represented as shown in the following equation:
max(tact)<tnom+Δtmax[12b]
the value presented in equation [12b] may occur at a STA in which the TSF comprises a “fast” system clock. Thus, the maximum time difference between a STA with a fast clock and a STA with a slow clock may be equal to 2·Δtmax.

In various embodiments of the invention, the time increment value may be determined as shown in the following equation:
TSF_inc≧2·Δtmax[13]
By utilizing the value TSF_inc as shown in equation [13], a selected supervisory STA_A112, which comprises a slow system clock, may generate a modified value TSF_val_mod, which is greater than the value TSV_val generated at a STA, which comprises a fast system clock. In this aspect of the invention, the generation of the modified value TSF_val_mod enables a STA with a fast system clock to time synchronize to a selected supervisory STA with a slow system clock. This may enable STAs within an IBSS102to predictably, and consistently time synchronize to the selected supervisory STA, and to adopt the network parameters utilized by the selected supervisory STA. Thus, in various embodiments of the invention, STAs within an IBSS102may time synchronize to a common system clock, and may utilize a common set of network parameters when communicating within the IBSS102.

In various embodiments of the invention, the time increment value may be represented as a function of the BeaconInterval as shown in the following equation:
TSF_inc≧┌2·(% errTSF)·BeaconInterval┐[14]
where % errTSVrepresents the percentage error in the accuracy of the TSF within the STA over a BeaconInterval time interval. BeaconInterval is the nominal time between beacon transmissions.

In various embodiments of the invention, a supervisory STA may transmit a beacon frame during any time interval during which a beacon frame, and/or announcement traffic information message (ATIM) frames, may be transmitted. The supervisory STA may transmit the beacon frame even when the supervisory STA has already received a beacon frame from another STA within the IBSS. In various embodiments of the invention, a supervisory STA may reduce its BeaconWindowLength to a value which is less than the value 2·aCWmin·aSlotTime. This may enable the supervisory STA to transmit a beacon frame at a time instant within the nominal beacon, which window may precede a time instant at which any of the subordinate STAs may transmit a beacon frame.

In various embodiments of the invention, an IBSS102may comprise more than one STA, which is configured to perform the supervisory STA role. In this aspect of the invention, each STA, which is configured to perform the supervisory STA role, may be configured with a priority value. The priority value is transmitted within the beacon frame by a STA_A112, which is contending for the supervisory STA role within the IBSS102. A STA_C116, which is also configured to perform the supervisory STA role, may inspect the priority value, priority_A, within the beacon frame received from the STA_A112. The STA_C116may compare the configured priority value, priority_C, and the received priority value, priority_A. When priority_A>priority_C, the STA_C116may concede the supervisory STA role to the STA_A112. In this aspect of the invention, the STA_C116may adopt a subordinate STA role relative to the STA_A112. The STA_C116may then adopt the timestamp value and network parameter values contained within the received beacon frame. When priority_C>priority_A, the STA_C116may not concede the supervisory STA role to the STA_A112. In this aspect of the invention, the STA_C116may not adopt a subordinate STA role relative to the STA_A112. The STA_C116may not adopt the timestamp value and network parameter values contained within the received beacon frame.

When priority_A=priority_C, the STA_C116may then inspect the source address (SA) field in the received beacon frame. The SA field may comprise an organizational unique identifier (OUI) portion, and a non-OUI portion. The SA field may correspond to an address associated with the STA_A112, which may have transmitted the beacon frame. In various embodiments of the invention, the STA_C116may compare the value of the OUI portion of the SA field, OUI(SA), and the OUI portion of the MAC address of STA_C, OUI(RCV_STA). When OUI(SA)>OUI(RCV_STA), the STA_C116may concede the supervisory STA role to the STA_A112. When OUI(SA)<OUI(RCV_STA), the STA_C116may not concede the supervisory STA role to the STA_112.

When OUI(SA)=OUI(RCV_STA), the STA_C116may compare the value of the non-OUI portion of the SA field, nOUI(SA), to the non-OUI portion of the MAC address of STA_C, nOUI(RCV_STA). When nOUI(SA)>nOUI(RCV_STA), the STA_C116may concede the supervisory STA role to the STA_A112. When nOUI(SA)<nOUI(RCV_STA), the STA_C116may not concede the supervisory STA role to the STA_112.

In various embodiments of the invention, a STA, which concedes the supervisory STA role, may not generate modified TSF values. In various embodiments of the invention, the priority value at a STA may be configured to be a determined value. In various embodiments of the invention, the priority value may be randomly generated at each STA.

FIG. 2Ais a block diagram for an exemplary beacon frame format, which may be utilized in an embodiment of the invention. With reference toFIG. 2Athere is shown a beacon frame format202. The beacon frame format202may comprise a frame control field204, a duration field206, a destination address field208, a source address field210, a BSSID field212, a sequence control field214, a QoS control field216, a beacon frame body218, and a frame check sequence (FCS)220.

The frame control field204may comprise information that identifies the frame as being a beacon frame. The duration field206may comprise a value, which is computed based on the data rate at which the beacon frame202is transmitted. The destination address field208may identify one or more STAs, which are intended to receive the beacon frame202. The source address field210may identify the STA, which transmitted the beacon frame202. The BSSID field212may identify a BSS to which the beacon frame is being directed. The sequence control field214may be utilized to indicate whether the frame202is a segment within a larger beacon frame. The QoS control field216associates the beacon frame202with a designated traffic class, or traffic stream. The QoS control field216enables transport of the beacon frame202within the IBSS based on a QoS specification associated with the traffic class or traffic stream. The beacon frame body218may comprise information that is specific to a beacon frame. The FCS field220may be utilized to detect and/or correct bit errors in a beacon frame202received at an STA. In various embodiments of the invention, the beacon frame body218comprises a timestamp, a set of network parameters and/or a supervisory intent indication. The supervisory intent indication may enable a STA to communicate to other STAs, that the sender of the beacon frame is attempting to assert a supervisory STA role within the IBSS102.

FIG. 2Bis a block diagram for an exemplary beacon frame body format, which may be utilized in connection with an embodiment of the invention. With reference toFIG. 2B, there is shown a beacon frame body format222. The beacon frame body format222may comprise a timestamp field224, a beacon interval field226, a capability information field228, an SSID field230, a supported rates field232, a frequency hopping (FH) parameter set field234, a direct sequence (DS) spread spectrum parameter set field236, a contention free (CF) parameter set field238, an independent BSS (IBSS) parameter set field240, a traffic information message field242an enhanced distributed channel access (EDCA) parameter set field244, and a supervisory intent indication field246.

The timestamp field224may indicate a time instant at which the beacon frame was transmitted. The timestamp value inserted into the timestamp field224may be determined based on the TSF_val generated by the TSF executing at the STA, which is transmitting the beacon frame. The beacon interval field226may indicate the amount of time that may transpire between beacon frame transmissions. The value of the beacon interval field226may correspond to the BeaconInterval value The capability information field228may be used to communicate capabilities available at the AP, which is transmitting the beacon frame. The SSID field230may identify the ESS to which the beacon frame is being directed. The supported rates field232may indicate data rates that may be supported by the AP, which is transmitting the beacon frame. The FH parameter set field234may comprise information, which enables STAs receiving the beacon frame to utilize frequency hopping when communicating with the AP that is transmitting the beacon frame. The DS parameter set field238may comprise information, which enables RF channel assignment to STAs when communicating with the AP. The CF parameter set field240may comprise information, which enables contention free polling of STAs. The IBSS parameter set240may comprise information, which may be utilized by a STA within an IBSS. The TIM information element242comprises information, which may enable an AP to indicate to STAs that data is buffered at the AP for delivery to one or more STAs. The EDCA parameter set244may enable STAs to make policy-based decisions related to the acceptance of data from other STAs based on QoS criteria. The supervisory intent indication246may enable a STA within an IBSS102to communicate other STAs an intent to perform a supervisory STA role.

FIG. 2Cis a block diagram for an exemplary supervisory intent indication information element, in accordance with an embodiment of the invention. With reference toFIG. 2C, there is shown a supervisory intent indication information element (IE)252. The supervisory intent indication IE252may comprise an element identifier (ID) field254, a length field256, an organizationally unique identifier (OUI) field257, a type field260and a priority field258. The element ID field254may identify the IE252as comprising vendor-specific information. The length field256may specify the combined length of the OUI field257, the type field260and of the priority field258. In various embodiments of the invention, the supervisory intent indication IE252is a vendor-specific IE. The vendor may be identified based on the OUI field257. The type field260may be utilized in conjunction with the OUI field257to identify the IE type as being a supervisory intent indication IE252. The priority field258may specify a priority level. The priority field258may enable resolution of supervisory STA and subordinate STA roles among a plurality of STAs within an IBSS102, which are attempting to assert a supervisory STA role.

FIG. 3is a flowchart illustrating exemplary steps for transmitting a beacon frame from a supervisory WLAN station in an independent basic service set, in accordance with an embodiment of the invention. Referring toFIG. 3, in step302, the STA_A112may be configured as a supervisory STA302. This may comprise generation of a priority value, priority_A. In step304, the STA_A112may compute a clock time increment value, TSF_inc. An exemplary TSF_inc value may be computed as shown in equation [14]. In step306, the STA_A112may determine the STA clock time value, TSF_val, generated by the TSF executing at the STA_A112. In step308, the STA112may generate a modified clock value TSF_val_mod. An exemplary TSF_val_mod value may be computed by adding the current TSF_val and the TSF_inc value. In step309, the STA clock time value, TSF_val, is adjusted based on the modified clock time value TSF_val_mod. In step310, the STA_A112may set the supervisory intent indication (SII) to indicate that the STA_A112is operating in a supervisory role. In step312, the STA_A112may transmit a beacon frame containing the SII and the TSF_val.

FIG. 4is a flowchart illustrating exemplary steps for receiving a beacon frame at a WLAN station in an independent basic service set, in accordance with an embodiment of the invention. Referring toFIG. 4, in step402, a STA_B114may receive a beacon frame. In step404, the STA_B114may determine whether it is configured to operate in a supervisory role. When the STA_B114is not configured to operate in a supervisory role, in step406, the STA_B114may compare the timestamp value, contained within the timestamp field224of the received beacon frame202, to the TSF_val value generated by the TSF executing at the STA_B114. Step408may determine whether the timestamp field224value is greater than the TSF_val value. When the timestamp field224value is greater than the TSF_val value, in step410, the STA_B114may adopt the network parameters contained within the beacon frame. In addition, the STA_B114may time synchronize to the STA, which transmitted the beacon frame by setting the TSF_val to the timestamp field224value.

When step408determines that the timestamp field224value is not greater than the TSV_val value, in step412, the STA_B114may maintain current STA parameters. The parameters maintained may include the TSV_val time value and various network parameters utilized by the STA_B114to enable communication with other STAs within the IBSS102.

When step404determines that the STA_B114is configured to operate in a supervisory role, step414may determine whether the received beacon frame202contains a supervisory intent indication246. When step414determines that the received beacon frame does not contain a supervisory intent indication, step412may follow and the STA_B114may maintain current STA parameters.

When step414determines that the received beacon frame does contain a supervisory intent indication, step416may determine whether the value of the priority field258within the beacon frame202is greater than the priority value configured at the STA_B114. When, in step416, the STA_B114determines that the beacon frame202contains the higher priority value, in step410, the STA_B114may adopt the network parameters contained within the beacon frame. In addition, the STA_B114may time synchronize to the STA, which transmitted the beacon frame by setting the TSF_val to the timestamp field224value.

When step416does not determine that the beacon frame priority value is greater than the STA_B114priority value, step418may determine whether the value of the priority field258is less than the priority value configured at the STA_B114. When step418determines that the value of the priority field258is less than the priority value configured at the STA_B114, step412may follow.

When step418determines that the value of the priority field258is equal to the priority value configured at the STA_B114, step420may determine whether the value of the OUI portion of the SA210is greater than the value of the OUI portion of the MAC address of the receiving STA. When step420determines that the OUI portion of the SA210is greater than the value of the OUI portion of the MAC address of the receiving STA, step410may follow.

When step420does not determine that the OUI portion of the SA210is greater than the value of the OUI portion of the MAC address of the receiving STA, step422may determine whether the OUI portion of the SA210is less than the value of the OUI portion of the MAC address of the receiving STA. When step422determines that the OUI portion of the SA210is less than the value of the OUI portion of the MAC address of the receiving STA, step412may follow.

When step422determines that the OUI portion of the SA210is equal to the value of the OUI portion of the MAC address of the receiving STA, step424may determine whether the non-OUI portion of the SA210is greater than the value of the non-OUI portion of the MAC address of the receiving STA. When step424determines that the non-OUI portion of the SA210is greater than the value of the non-OUI portion of the MAC address of the receiving STA, step410may follow. When step424determines that the non-OUI portion of the SA210is not greater than the value of the non-OUI portion of the MAC address of the receiving STA, step412may follow.

Aspects of an exemplary system for an ad hoc wireless network with master control of network parameters may comprise one or more circuits that enable generation of a beacon frame at a supervisory STA_A112wherein the generated beacon frame contains a supervisory role indication, which enables the supervisory STA_A112to establish timing synchronization and network parameters that are utilized by a plurality of WLAN stations utilized for communicating within an IBSS102. The plurality of communicating devices may comprise the supervisory STA_A112and at least one subordinate STA_B114. The WLAN may be an IBSS as defined by IEEE 802.11 standards. The beacon transmission time interval, BeaconInterval, may indicate the time duration between the start of transmission of a current beacon frame at the STA_A112, and the start of transmission of a succeeding beacon frame. The STA_A112may compute a time increment value, TSF_inc, based on the BeaconInterval value and a percentage error in a system clock time value, % errTSF. The STA_A112may compute a timestamp value, TSF_val_mod based on the TSF_inc value and the TSF_val value generated by a TSF executing on behalf of the STA_A112. The STA_A112may modify the system clock time value TSF_val value based on the computed TSF_val_mod. The TSF may generate subsequent system clock time values based on the modified TSF_val. The generated beacon frame may comprise the computed timestamp value TSF_val_mod.

The supervisory role indication may comprise a priority value. The beacon frame may be transmitted during a time instant that occurs during a beacon transmission time window. The duration of the beacon transmission time window may be determined based on the minimum contention window time duration, aCWmin. At the supervisory STA_A112, the duration of the beacon transmission time window may be determined based on a value that is less than aCWmin.

Aspects of the system may also comprise a STA_B114that enables communication via an IBSS102by utilizing a timestamp value and network parameter values retrieved from a received beacon frame based on the presence of a supervisory role indication within the received beacon frame. The STA_B114may determine whether it is configured to operate in a supervisory role. The STA_B114may determine whether a configured priority value is greater than, less than or equal to, a beacon priority value retrieved from the received beacon frame. The timestamp value and network parameter values may be utilized by the STA_B114when the beacon priority value is greater than the station priority value. The STA_B114may determine whether an OUI portion of the source address (SA) is greater than, less than or equal to, an OUI portion of the MAC address of STA_B114. The timestamp value and network parameter values may be utilized by the STA_B114when the beacon priority value is equal to the station priority value and the OUI portion of the SA is greater than the MAC address of STA_B114. The STA_B114may determine whether a non-OUI portion of the SA is greater than, less than or equal to, a non-OUI portion of the MAC address of STA_B144. The timestamp value and network parameter values may be utilized by the STA_B114when the beacon priority value is equal to the station priority value, the OUI portion of the SA is equal to the OUI portion of the MAC address of STA_B144and the non-OUI portion of the SA is greater than the non-OUI portion of the MAC address of STA_B144.

Another embodiment of the invention may provide a machine-readable storage, having stored thereon, a computer program having at least one code section executable by a machine, thereby causing the machine to perform the steps as described herein for an ad hoc wireless network with master control of network parameters.