Methods, apparatuses, and computer programs for determining when to change values of privacy enhancement parameters of a multi-link wireless station in a BSS context

Abstract

At least one embodiment of a method for changing a value of at least one privacy parameter of at least one station in a group of stations. After a reference time has been obtained and a pseudo-random number has been obtained, a time at which the value of the at least one privacy parameter is to be modified is determined from the obtained reference time and the obtained pseudo-random number, the reference time being obtained directly or indirectly from an initial reference time and a time interval to be applied iteratively.

Description

Technical Field

[0001] This disclosure relates to wireless communications, and more specifically to user privacy during wireless communications. Background Technology

[0002] The methods described in this section can be implemented, but are not necessarily methods previously conceived or implemented. Therefore, unless otherwise indicated herein, the methods described in this section are not prior art as claimed in this application, and are not admitted to be prior art by virtue of their inclusion in this section. Furthermore, all embodiments are not necessarily intended to solve all or even any of the problems raised in this section.

[0003] Today, the evolution of wireless systems, driven by user demands and the requirements of the General Data Protection Regulation (GDPR), has brought forward cutting-edge privacy issues. While continuing to improve wireless services and user experience, the global wireless industry faces a growing need to protect users' personally identifiable information from increasingly sophisticated user tracking and profile-building activities.

[0004] Specifically, the Media Access Control (MAC) address of a user's device constitutes data that can be used to track that user. In practice, an access point (AP) of a wireless network can monitor the location of a user's mobile device (tablet, laptop, mobile phone, etc.) without their consent by means of its MAC address. This is because mobile phones are configured to discover nearby access points for wireless networks. When a user moves, their mobile phone sends requests to determine if any access points are nearby; these requests identify the mobile phone sending the requests and specifically include the mobile phone's MAC address. Access points that hear these requests can respond. In the context of Wi-Fi networks (Wi-Fi is a trademark) as defined by the IEEE 802.11 standard, this process is called a probe request / response exchange.

[0005] Therefore, even when a mobile phone is not connected to a Wi-Fi network, nearby access points can receive its MAC address. The user can then be tracked by reconstructing their trajectory from the access points to which their mobile phone has sent its MAC address. Additionally, if the mobile phone is already associated with one of the access points (i.e., the user has connected to an associated Wi-Fi network through that access point) and the user has previously provided personal identification information (name, address, etc.), the access point may already have the MAC address of the phone associated with that identification information item recorded in its database. Therefore, even if the user is not connected to a Wi-Fi network, these identification information items can be recovered by comparing the MAC address included in the probe request with the MAC address used for past associations.

[0006] In the context of Wi-Fi networks, the IEEE 802.11 working group has proposed a solution to limit the risk of user tracking, which involves dynamically modifying the MAC address of user devices. This mechanism is known as the Randomized and Modified MAC (RCM) process. The RCM process was initially introduced as a privacy enhancement feature in the 802.11aq Pre-Association Service Discovery Task Group and was eventually included in the standard IEEE Std 802.11-2020. The RCM process involves the periodic modification of the MAC address of a non-AP station or STA (i.e., a station that is not an access point) to a random value. Non-AP stations are not associated with the network (or equivalently, with an access point). Non-AP stations can construct randomized MAC addresses based on locally managed address spaces as defined in IEEE Std 802®-2014 and IEEE Std 802c™-2017.

[0007] More specifically, a new Management Information Base (MIB) variable has been specified that can be controlled by an external management entity. This variable is called "dot11MACPrivacyActivated". When dot11MACPrivacyActivated is set to "true", non-AP stations can apply specific mechanisms to enhance MAC-level privacy, including RCM.

[0008] A device's MAC address, or EUI-48 address, is a 48-bit Extended Unique Identifier (EUI). MAC addresses can be managed generically or locally. Generically managed addresses are uniquely assigned to devices by the manufacturer. In contrast, locally managed addresses are assigned to devices by software or network administrators and supersede physically programmed addresses. The second least significant bit of the first eight bytes of the MAC address (i.e., the seventh bit of the first eight bytes, also known as the "U / L bit" for "generic / local bit") indicates whether it is generically managed (when set to 0) or locally managed (when set to 1). The least significant bit of the first eight bytes of the MAC address (i.e., the eighth bit of the first eight bytes, also known as the "I / G bit" for "individual / group bit") indicates whether the frame is sent to only one receiving device (when set to 0, indicating unicast transmission) or multiple devices (when set to 1, indicating multicast transmission). When operating the RCM mechanism in a non-AP station, the MAC address of the non-AP station changes randomly (e.g., periodically). More specifically, the U / L bit is set to 1, the I / G bit is set to 0, and the remaining 46 bits are randomly generated using a pseudo-random function (PRF), or can be obtained by any other means (e.g., received from the AP, or obtained from a predefined list of addresses).

[0009] Unfortunately, given the advanced techniques used in data traffic analysis to create a digital fingerprint of a device, RCM is insufficient to protect device privacy. To overcome this problem, a set of Enhanced Data Privacy (EDP) parameters has been identified that would allow eavesdroppers to fingerprint a device. Among these EDP parameters, identifiers such as MAC addresses or Association Identifiers (AIDs) are certainly the most important, but other parameters such as sequence numbers (SNs) or packet numbers (PNs) present in the unencrypted portions of data frames are also listed.

[0010] Within the currently drafted standard IEEE 802.11bi, solutions have been proposed to modify the EDP parameters (including MAC addresses) of stations associated with access points (APs) to prevent tracking by potential eavesdroppers. It has been observed that EDP parameters can be divided into two subcategories: Client Privacy Enhancement (CPE) parameters, specifically designed to enhance data privacy for client (non-AP) parameters, and BSS Privacy Enhancement (BPE) parameters, specifically designed to enhance privacy within the Basic Service Set (BSS). Therefore, CPE parameters prevent non-AP stations from being tracked within a given BSS or Extended Service Set (ESS), while BPE parameters prevent AP stations, especially mobile AP stations (e.g., mobile phones sharing an internet connection via Wi-Fi with other devices such as cameras or gaming devices), from being tracked.

[0011] To prevent non-AP stations from being tracked, the set of EDP parameters should only be valid for a finite period of time called the epoch. Specifically, existing solutions to the tracking problem rely on the fact that both the AP and non-AP stations are simultaneously changing MAC addresses on their respective sides. For this, both the AP and non-AP stations need to know the epoch start time. Not only do both need to know the epoch start time, but it should also be accurate enough to avoid discarding frames that are not addressed with the expected address from the receiver's perspective. Furthermore, when several non-AP stations are associated with the same AP, it is beneficial to simultaneously change the set of non-AP stations (especially to create additional confusion in the eavesdropper's mind). In the latter case, both the set of non-AP stations and the AP station should know the epoch time.

[0012] To enable access points (APs) and one or more non-APs to share the epoch start time, recent solutions have proposed relying on a time defined by conventional absolute time (timing synchronization function or TSF time) or on a constant time (offset) relative to the received frame (typically a beacon frame). According to some solutions, a TSF counter is transmitted in each beacon frame. This is a 64-bit value indicating the time (in μs) that has elapsed since the link was enabled.

[0013] Unfortunately, the proposed solution has a serious drawback regarding privacy enhancement: an eavesdropper can easily determine the timing of a change after a period of traffic analysis and address changes. The eavesdropper can then easily associate the appearing addresses with the disappearing ones.

[0014] Therefore, there is a need for a mechanism that allows non-AP stations to change their privacy-enhancing parameters at precise moments in time, moments that are easily determined by both the AP station and the set of non-AP stations (one, several, or all of the non-AP stations associated with the AP station), rather than by an eavesdropper. Summary of the Invention

[0015] This disclosure has been designed to address one or more of the aforementioned problems.

[0016] Within the scope of RCM, determining the start time of a new epoch is the key point of the MAC address change mechanism.

[0017] This disclosure describes a method for determining the start time of an epoch with reduced information exchange, and associated functions for calculating privacy-enhancing parameters.

[0018] This disclosure covers individual epochs initiated to a single non-AP MLD, as well as group epochs managed by an AP and used to change multiple stations at once (potentially all non-AP MLDs on a given BSS).

[0019] The common term for a group or individual epoch is an EDP (Enhanced Data Privacy) epoch, and as a reminder, EDP parameters are CPE or BPE parameters.

[0020] The EDP epoch is a time window in which the set of EDP parameters remains constant. EDP epoch operation is an EDP feature that is effective when MLO (Multi-Link Operation) is supported. MLO allows multi-link devices to establish or set up multiple links and operate them simultaneously. For MLD STAs, their active EDP epoch ends at the start of the next active EDP epoch.

[0021] An EDP epoch is either an individual EDP epoch or a group EDP epoch.

[0022] An individual EDP epoch is a time window of a set of EDP parameters that are valid for the duration of a single non-AP MLD application within that individual EDP epoch.

[0023] An individual EDP epoch is initiated by a non-AP MLD and acknowledged by its associated AP MLD. EDP epoch parameters are a set of parameters characterizing an EDP epoch. The EDP epoch parameters of an individual EDP epoch are negotiated between the non-AP MLD and its associated AP MLD. The non-AP MLD applies the negotiated EDP epoch parameters of the individual EDP epoch to determine the start time of one or more corresponding EDP epochs.

[0024] A group EDP epoch is a time window of the set of EDP parameters that are valid for the duration of each non-AP MLD applied to the individual non-AP MLDs within that group EDP epoch.

[0025] A group EDP epoch is initiated by an AP MLD by advertising EDP epoch parameters to a set of non-AP MLDs. The EDP epoch parameters of the group EDP epochs advertised by each non-AP MLD in the non-AP MLD set determine the same start time for one or more EDP epochs.

[0026] It is worth distinguishing between EDP epoch parameters, which are a set of parameters characterizing the EDP epoch, and EDP parameters, which are CPE or BPE parameters as defined above. EDP parameters are also called FA (Frame Anonymity) parameters because these parameters are used to enhance data privacy by anonymizing frame exchange.

[0027] The EDP epoch parameters correspond to a set of parameters used to determine the start time of the EDP epoch based on a fixed epoch interval with finite pseudo-random variation. The process of determining the EDP epoch parameter values ​​corresponds to the process of setting the EDP parameter values ​​and is referred to as EDP epoch setting.

[0028] In this disclosure, the terms "group epoch" and "group EDP epoch" are used interchangeably. Furthermore, the terms "individual epoch" and "individual EDP epoch" are used interchangeably.

[0029] According to an aspect of this disclosure, a method is provided for changing the value of at least one privacy parameter of at least one station in a group of stations, the method comprising:

[0030] A reference time is obtained, which is obtained directly or indirectly based on an initial reference time and the time interval to be iteratively applied;

[0031] Obtain pseudo-random numbers; and

[0032] The time for modifying the value of the at least one privacy parameter is determined based on a reference time and a pseudo-random number.

[0033] Therefore, the method disclosed herein enables improvements in the protection of personal data without complicating the processing used or increasing the resources required.

[0034] According to some embodiments, the method further includes: obtaining the iteration number of the current iteration, the iteration number being obtained based on the initial reference time, the time interval, and the current time, the reference time being obtained based on the iteration number.

[0035] According to some embodiments, the initial reference time and the time interval are obtained from another station in the station group, respectively, as the group initial reference time and the group time interval, and the time for modifying the value of the at least one privacy parameter is the group time for modifying the value of the at least one privacy parameter. The method further includes:

[0036] Obtain the initial reference time and individual time interval for each individual;

[0037] An individual reference time is obtained, which is obtained directly or indirectly based on the individual's initial reference time and the individual's time interval;

[0038] Obtain individual pseudo-random numbers; and

[0039] The individual time at which the value of the at least one privacy parameter is to be modified is determined based on the obtained reference time and the obtained individual pseudo-random number.

[0040] Therefore, the method disclosed herein makes it possible to combine group methods and individual methods for changing the value of the privacy parameter to change the value of the privacy parameter as needed.

[0041] According to some embodiments, the method further includes: comparing the determined individual time with at least one determined group time, wherein if the difference between the determined individual time and the at least one determined group time is less than a threshold, only one of the determined individual time and the at least one determined group time is selected to change the value of the at least one privacy parameter.

[0042] According to some embodiments, the method further includes:

[0043] A request is transmitted to the other station to change the value of at least one privacy parameter of the at least one station, the request including at least the individual's initial reference time and the individual's time interval.

[0044] Specifically, upon receiving a response to the request, the individual reference time is obtained and the individual time for which the value of the at least one privacy parameter is to be modified is determined.

[0045] According to some embodiments, the method further includes:

[0046] A request is transmitted to the other station to change the value of at least one privacy parameter of the at least one non-access point.

[0047] Specifically, upon receiving a response to the request, the individual reference time is obtained and the individual time for which the value of the at least one privacy parameter needs to be modified is determined. The response to the request includes at least the individual initial reference time and the individual time interval.

[0048] According to some embodiments, a policy is received from the other station along with the initial reference time and the time interval, wherein the individual time and / or the group time for changing the value of the at least one privacy parameter are selected based on the received policy.

[0049] According to some embodiments, the method further includes:

[0050] A request is transmitted to another station in the station group to change the value of at least one privacy parameter of the at least one station, the request including at least the initial reference time and the time interval.

[0051] Specifically, upon receiving a response to the request, the process includes obtaining the reference time and determining the time at which the value of the at least one privacy parameter needs to be modified.

[0052] According to some embodiments, the method further includes:

[0053] A request is transmitted to another station in the station group to change the value of the at least one privacy parameter of the at least one station.

[0054] Specifically, upon receiving a response to the request, the process includes obtaining the reference time and determining the time at which the value of the at least one privacy parameter needs to be modified. The response to the request includes at least the initial reference time and the time interval.

[0055] According to some embodiments, the method further includes: starting a timer, wherein the timer expires at the time when the value of the at least one privacy parameter is to be modified.

[0056] According to some embodiments, the method further includes: calculating and storing the value of the at least one privacy parameter for a previous iteration, the current iteration, and / or the next iteration.

[0057] According to some embodiments, the same pseudo-random function is used once to obtain the pseudo-random number and to calculate the value of the at least one privacy parameter.

[0058] According to some embodiments, when the timer expires, the stored value of the at least one privacy parameter is restored and applied.

[0059] According to some embodiments, the value of the at least one privacy parameter that is recovered and applied is a value for the current iteration, and the method further includes: recovering and applying the value of the at least one privacy parameter for the iteration immediately preceding the current iteration within a given time period.

[0060] According to some embodiments, the method also includes obtaining a time range, wherein the obtained pseudo-random number belongs to the obtained time range.

[0061] According to some embodiments, the at least one station is at least one non-access point (non-AP) station, the group of stations includes access point (AP) stations, and the at least one non-AP station is associated with the AP station.

[0062] According to some embodiments, the non-AP station and the AP station are multi-link devices, i.e., MLDs, and the time to modify the value of the at least one privacy parameter is also determined based on the time offset of the reference link.

[0063] According to some embodiments, the at least one privacy parameter is at least one Client Privacy Enhancement (CPE) parameter. The at least one CPE parameter includes a public identifier, which is a MAC address or an Association Identifier (AID).

[0064] In other words, this disclosure provides a method that allows a set of non-AP stations associated with the same AP to change their CPE parameters while the AP makes that change, and easily adds non-AP stations to an already established station group. This disclosure relies on a set of times (hereinafter referred to as reference times) determined at a fixed frequency starting from an initial time T0, and on pseudo-random variation times (hereinafter referred to as...) around these reference times. The reference time (T) is used to determine the start time of the effective epoch. This mechanism has significant advantages over previous solutions. Since the reference time is defined by an arithmetic sequence of time, it is easy to determine any future or past moment in the series using very few parameters (initial moment, arithmetic step size, and current time).

[0065] Of course, up to this point, the arithmetic sequence itself is insufficient to ensure privacy, because an eavesdropper could easily determine the sequence parameters. This is why the proposed solution also utilizes pseudo-random generation using a shared secret to compute pseudo-random variations around a reference time. The reason for T).

[0066] Using a reference time as the start time for generating a valid epoch (reference time + ... T) The station guarantees the following effective epoch start time for the pseudo-random generator T, which is random from the eavesdropper's perspective but deterministic for the station that knows the secret parameters.

[0067] Furthermore, using an arithmetic sequence defined by an initial time T0 and a fixed time interval (TI) allows newly associated stations (or stations awakened after a long sleep period) to join a group and determine the start time (GET) of the next epoch, without requiring additional or specific information exchange between the AP and the station. According to one embodiment of this disclosure, a newly associated station (or a station awakened after a long period) can join a group by comparing the current time T with a reference time (n = [(T-T0) / TI], where [x] represents the integer part of x, belonging to...). The current iteration number n of the sequence can be easily determined by comparison. The first iteration is equal to 0.

[0068] In some embodiments, the proposed solution aligns reference times by adding a constant offset to the TSF across different links of the MLD, thereby allowing simultaneous epoch start times on several links of the same non-AP station MLD.

[0069] In some embodiments, the group can be reduced to just one station. In this case, the epoch is referred to as an individual epoch, and the epoch initiator (the station that sends the epoch sequence parameters) can be a non-AP station. This final embodiment allows non-AP stations to adapt the BSS's privacy policy to their own needs by, for example, requesting to change their CPE parameters more frequently.

[0070] In some embodiments, group eras and individual eras coexist in the same BSS, and additional rules are defined to avoid conflicts between different eras by preventing the overlap of transition periods of eras belonging to the same non-AP station (belonging to at least one group era and one individual era).

[0071] The proposed mechanism for determining the start of an epoch and associated CPE parameters based on TSF is simple and does not require additional mechanisms for synchronization (the TSF mechanism is sufficient).

[0072] Both AP and non-AP STA can calculate CPE parameters at any time. This includes currently used CPE parameters, previous CPE parameters, or even future CPE parameters and their associated usage time.

[0073] The information required for CPE parameter and epoch boundary calculations needs to be low-overhead because the data is sent only once to initiate a series of epochs.

[0074] The proposed mechanism also allows for the coexistence of individual epochs and group epochs.

[0075] At least a portion of the methods according to this disclosure may be computer-implemented. Therefore, this disclosure may take the form of a completely hardware embodiment, a completely software embodiment (including firmware, resident software, microcode, etc.), or an embodiment combining software and hardware aspects, which may generally be referred to herein as a “circuit,” “module,” or “system.” Furthermore, this disclosure may take the form of a computer program product embodied in any tangible medium having computer-usable program code embodied therein.

[0076] Because this disclosure can be implemented in software, it can be embodied as computer-readable code for provision to a programmable device on any suitable carrier medium. Tangible non-transient carrier media may include storage media such as floppy disks, CD-ROMs, hard disk drives, magnetic tape devices, or solid-state storage devices. Transient carrier media may include signals such as electrical signals, electronic signals, optical signals, acoustic signals, magnetic signals, or electromagnetic signals (e.g., microwave or RF signals). Attached Figure Description

[0077] Embodiments of this disclosure will now be described by way of example only and with reference to the following figures, in which:

[0078] Figure 1 Examples of network systems that can implement some embodiments of this disclosure are shown;

[0079] Figure 2a Examples of steps performed in a non-AP station when it is added to a group epoch sequence, according to some embodiments of the present disclosure, are shown;

[0080] Figure 2b Examples of steps performed in a non-AP station when starting a new individual epoch series, according to some embodiments of this disclosure, are shown;

[0081] Figure 3a Examples of group epoch start time sequences for non-AP station groups associated with the same AP station are shown according to some embodiments of this disclosure;

[0082] Figure 3b Described with Figure 3a Related and Figures 8a to 8c The formula for calculating timed events used;

[0083] Figure 4a An example of the individual epoch start time series of a single non-AP station associated with an AP station is shown;

[0084] Figure 4b Some embodiments according to this disclosure are shown and Figures 8a to 8c The use of and Figure 4a Related timed event calculation formulas;

[0085] Figure 4c An example of the EDP epoch sequence of a single non-AP station associated with an AP station according to the implementation is shown;

[0086] Figure 4d An example is shown based on the realized continuous EDP epoch sequence and its associated EDP epoch start time and transition period;

[0087] Figure 5 An example of the coexistence of group epochs and individual epochs of non-AP stations associated with AP stations is shown;

[0088] Figure 6 An example of an association of a multi-link device configured to implement at least some embodiments of the present disclosure is illustrated schematically;

[0089] Figure 7a The STA information subfield of the basic multilink information element transmitted by an AP attached to an AP MLD, as defined in IEEE 802.11be revision, is shown.

[0090] Figure 7b Information elements containing parameters of a group epoch series are shown according to some embodiments of this disclosure;

[0091] Figure 7c Examples of frame formats for individual epoch series requests are shown according to some embodiments of this disclosure;

[0092] Figure 7d Examples of frame formats for individual epoch series responses according to some embodiments of this disclosure are shown;

[0093] Figure 7e Examples of frame formats for (enhanced data privacy) epoch request frames according to some embodiments of this disclosure are shown;

[0094] Figure 7f Examples of frame formats for (enhanced data privacy) epoch response frames according to some embodiments of this disclosure are shown;

[0095] Figure 7g Examples of information elements (IEs) containing parameters of an epoch series (individual or group) according to some embodiments of this disclosure are shown;

[0096] Figure 8a Examples of steps performed at a non-AP station when waking up after a sleep period, according to some embodiments of the present disclosure, are shown;

[0097] Figure 8b Examples of steps performed in a station (AP station or non-AP station belonging to a group) when the associated group epoch timer expires and a new group epoch is about to begin, according to some embodiments of this disclosure, are shown.

[0098] Figure 8c Examples of steps performed in a station (AP station or non-AP station) when an individual epoch timer expires and a new individual epoch is about to begin, according to some embodiments of this disclosure, are shown.

[0099] Figure 9a Examples of frame switching sequences performed in an AP station to initiate a group epoch series are shown according to some embodiments of the present disclosure;

[0100] Figure 9b Examples of frame-swapping sequences are shown according to some embodiments of this disclosure when a non-AP station wants to initiate an individual epoch series;

[0101] Figure 9c Examples of frame exchange between a requesting station and a responding station according to some embodiments of this disclosure to request the creation of an EDP epoch sequence are shown; and

[0102] Figure 10An example of a communication device configured to implement at least some embodiments of the present disclosure is illustrated schematically. Detailed Implementation

[0103] According to some embodiments of this disclosure, it is determined in the BSS context when to change the values ​​of privacy enhancement parameters of a multi-link radio station, particularly the values ​​of client privacy enhancement (CPE) parameters.

[0104] An instance of a CPE parameter change defines a series of usage periods (indexed as 'epochs', 0, 1, ..., n, n+1, etc.) during which a given value of the CPE parameter (e.g., a MAC address) will be used. In some implementations, a usage period begins with a transition period during which both the old value (related to the previous usage period 'n') and the new value (related to the current usage period 'n+1') of the CPE parameter can be considered. In some implementations, constraints can be imposed on the use of the old value during the transition period. For example, the old MAC address@MAC(n) can be allowed as the sender address for the transmission of frames that have already been generated and buffered, but the old MAC address@MAC(n) can no longer be used for the generation of new frames because the current usage period (n+1) has begun, and therefore the new MAC address@MAC(n+1) should be used. In other implementations, changes to CPE parameters are strictly applied between two usage periods; that is, no transition period is implemented, and only CPE parameters (e.g., CPE_parameters(n)) for a given usage period (e.g., usage period 'n') should be used.

[0105] In any case, accurately determining the start time of the epoch is essential for the parameter change mechanism to function properly.

[0106] According to some embodiments of this disclosure, a set of times (hereinafter referred to as the reference time) is determined based on a fixed frequency starting at an initial time T0, and pseudo-random time variation (hereinafter referred to as...) is used. T) The effective epoch start time is determined based on each reference time. The effective epoch start time can be determined for a specific non-AP station (individual epoch start time), or it can be determined for all non-AP stations in a station group (group epoch start time).

[0107] Figure 1 Examples of network systems that can implement some embodiments of this disclosure are shown.

[0108] For the sake of explanation, Figure 1This represents an 802.11 network (i.e., Wi-Fi network) system 100 comprising four wireless devices: an access point station (AP) 105 and three non-AP stations (STAs) 110a, 110b, and 110c. The AP and non-AP stations can be AP multilink devices (MLDs) and non-AP MLDs, respectively. Of course, the number of non-AP stations 110a, 110b, and 110c can be more than three. AP station 105 provides wireless connectivity between the non-AP stations 110a, 110b, and 110c and a wider network, such as the Internet (not shown). A connection from one of the non-AP stations 110a, 110b, and 110c to AP 105 can be established through a standardized process known as association. Once a non-AP station is associated with an AP station, it can send and receive data from the network through the AP station.

[0109] AP station 105 may include, be implemented as, or be referred to as Node B, Radio Network Controller (RNC), Evolved Node B (eNB), 5G Next Generation Base Station (gNB), Base Station Controller (BSC), Base Transceiver Station (BTS), Base Station (BS), Transceiver Function (TF), Radio Router, Radio Transceiver, Basic Service Set (BSS), Extended Service Set (ESS), Radio Base Station (RBS), or any other term. AP station 105 may be a standalone product, or it may be integrated into an apparatus, such as an integrated Broadband Remote Access Server (BRAS).

[0110] Non-AP stations 110a, 110b, and / or 110c may include, be implemented as, or be referred to as a subscriber station, subscriber unit, mobile station (MS), remote station, remote terminal, user terminal (UT), user agent, user device, user equipment (UE), subscriber station (STA), or some other term. In some implementations, a non-AP station may be or may include a cellular phone, cordless phone, Session Initiation Protocol (SIP) phone, Wireless Local Loop (WLL) station, personal digital assistant (PDA), handheld device with wireless connectivity, or some other suitable processing device connected to a wireless modem. Accordingly, one or more aspects of the teachings herein may be incorporated into a telephone (e.g., a cellular phone or smartphone), a computer (e.g., a laptop computer), a tablet computer, a portable communication device, a portable computing device (e.g., a personal data assistant), an entertainment device (e.g., a music or video device, or a satellite radio), a Global Positioning System (GPS) device, or any other suitable device configured to communicate via wireless or wired media. In some respects, some of the non-AP stations 110a, 110b, and 110c can be wireless nodes. Such wireless nodes can provide connectivity to or from a network (e.g., a wide area network such as the Internet or a cellular network) via wired or wireless communication links.

[0111] AP station 105 manages a set of stations that collectively organize their access to the wireless medium for communication purposes. All stations (AP station 105 and non-AP stations 110a, 110b, and 110c) form a service set, which may be referred to as a Basic Service Set (BSS) (although other terms may be used). Note that AP station 105 can manage more than one BSS: each BSS is therefore uniquely identified by a specific Basic Service Set Identifier (BSSID) and managed by separate virtual AP stations implemented within the physical AP station 105.

[0112] Figure 2a and Figure 2b An example of the steps for setting up a non-AP station to determine the effective epoch start time is shown.

[0113] Figure 2a Examples of steps performed in a non-AP station when it is added to a group epoch sequence according to some embodiments of this disclosure are shown. A group epoch sequence (or group epoch series) is a sequence of epochs from a set of non-AP stations associated with the same AP, used to simultaneously change the values ​​of privacy enhancement parameters. The group epoch sequence can be defined by a set of parameters (group epoch parameters or group epoch series parameters) including a group epoch reference time (T0) and a group epoch interval (GEI), thereby enabling the calculation of a valid epoch start time. The group epoch sequence may also include other parameters such as a time range for the pseudo-random number to be used to calculate the valid epoch start time, a policy, and / or a reference link (RefLink ID) to be used as a time reference.

[0114] When a non-AP station determines that it has been added to the group epoch series, execute... Figure 2a The steps are shown. This can be achieved, for example, by receiving (e.g., in a beacon, in a probe response, or in an associated response frame) information elements that include group epoch series parameters (e.g., Figure 7b The information element (IE) 720 in the document is used to perform this when a non-AP station is associated with an AP. This can also be done when a group epoch instruction is received (e.g., Figure 9a The epoch was completed during the period from 910 to 912 (as indicated in the group epoch).

[0115] In some embodiments, a non-AP MLD receives group epoch parameters from its AP MLD (epoch initiator), including: GEI = Group Epoch Interval, T0 = Initial Group Epoch Reference Time, Time Range, and RefLink ID.

[0116] The epoch parameters (GEI, T0, Time range, and RefLink Id of the reference link used as a time reference) have the same values ​​for all links and are used to determine the epoch start time and non-AP STA CPE parameters.

[0117] For reference Figures 7b to 7g As described, epoch parameters can be sent in encrypted IEs or encrypted frames.

[0118] After association, each non-AP MLD calculates a value n corresponding to the number of group epochs elapsed since the last TSF reset on its main link:

[0119] n = [(current TSF –T0– RefLink Offset) / GEI]

[0120] The non-AP STA can then determine the next set of epoch reference times:

[0121] T n+1 =T0+ (n+1) × GEI

[0122] Then, before the next set of epoch reference times, non-AP STAs and AP stations calculate the CPE parameters for non-AP STAs:

[0123] CPE_PARAMn+1 = PRF-M\L(PTK , “ERCM”, Tn+1)

[0124] Tn+1 = PRF-128\64(GTK , “ERCM”, Tn+1) mod (Time range)

[0125] GETn+1 = Tn+1 + Tn+1 + RefLink Offset.

[0126] This embodiment emphasizes using a time reference as input for the CPE parameters used to generate this epoch.

[0127] like Figure 2a As shown in step 200, the non-AP station recovers the group epoch series parameters from its internal memory. These parameters can be included in the last received information element, which is contained, for example, in a beacon (e.g.,...). Figure 9a In the beacon 900) or group epoch indicator (e.g., Figure 9aThe group epoch indicator (910) is used. These parameters can include the start time (T0) and the fixed group epoch interval (GEI), as well as the strategy.

[0128] Figure 9a Some examples of frame switching that provide group epoch series parameters to non-AP stations are described. Upon receiving the values ​​of these parameters, the non-AP station stores the values ​​of the group epoch series parameters in its internal memory.

[0129] Next, in step 202, non-AP stations, for example, use Figure 3b Formula 332 determines the current group epoch iteration value, denoted as n, based on the TSF time, group epoch reference time (T0), and group epoch interval (GEI):

[0130] n = [(current TSF –T0– RefLink Offset) / GEI]

[0131] in:

[0132] T0 and GEI are part of the epoch series parameters, and

[0133] RefLink Offset = The offset of the current link's TSF counter compared to the reference link (id RefLink ID), with a resolution of 2μs.

[0134] T0 is the value of the first reference time of the epoch on the reference link.

[0135] Note that if no beacon is received on the current link (e.g., multi-link power-saving mode), it cannot be transmitted via TSF offset (e.g., Figure 7a The TSF offset (710) is read directly from the RefLink Offset. If the reference link selected by AP MLD 600 is Link 1 (e.g., ... Figure 6 As shown in the image, this is also the case.

[0136] In this case, the RefLink Offset can be approximated using the two TSF offset fields 710 of the basic multilink information element received on the reporting link:

[0137] TSF Offset field in RefLink received beacon: TSF Offset RefLink = Floor((TSF RefLink –TSF Reporting ) / 2).

[0138] RefLink Offset = 2 × TSF OffsetRefLink

[0139] = 2 × Floor ((TSF RefLink - TSF current ) / 2)

[0140] ≈ Floor ((TSF RefLink - TSF reporting ) / 2) – Floor ((TSF Current -TSF Reporting ) / 2)

[0141] ≈ 2 × (TSF Offset RefLink – TSF Offset current )

[0142] In step 204, the start time of the next epoch in the station's epoch series is denoted as GET. n To this end, the station first restores the latest group epoch series parameters stored in memory (step 200), and then, for example, uses... Figure 3b Formula 330 in the formula calculates the start time of the next epoch. Formula 330 is read as follows:

[0143] GET n =T n + T n + RefLink Offset

[0144] in:

[0145] - n is the number of iterations incremented by 1 compared to the recovered value (i.e., n = n + 1). In some embodiments, the value of n is not determined based on the stored value, but rather using... Figure 3b Formula 332 in the text is used for direct calculation;

[0146] - Tn is the reference time at iteration n, which can be used... Figure 3b The value Tn is determined by one of the formulas 331 in the formula. In some embodiments, the value Tn is obtained according to the following formula, benefiting from the previous value stored in memory at step 208 during the CPE parameter calculation:

[0147] Tn = Tn-1 + GEI. In some embodiments, the initial reference time T0 is used according to the following formula (e.g., Figure 3a The reference time T0 (300) and the iteration value n are used to calculate Tn: Tn = T0 + (n × GEI);

[0148] - Tn It is the pseudo-random change time at iteration n. For the sake of illustration, T n This can be computed using a shared pseudo-random generation function, which takes input parameters from those shared among stations belonging to groups associated with the group epoch series, and at least a reference time Tn. Figure 3b Formula 333 in the formula provides the determination T n Example:

[0149] T n =PRF-128\64(GTK , “ERCM”, T n ) mod (Time range)

[0150] The PRF-128 function is defined as in the IEEE 802.11 series. In this example, the function generates 128 pseudo-random bits, and only retains the first 64 pseudo-random bits for generation. T n (As shown in the 128\64 notation). In this example, the secret key GTK is used as the input to the function. It is derived from GTK (which is a key provided by the AP to non-AP stations during association) and is then known to all stations associated with the AP. The final input parameter "ERCM" is a context indicating that the generation is specifically designed to enhance randomization and modify MAC address characteristics. Finally, to obtain time range values ​​(e.g., Figure 7b The duration within the predetermined duration range of the time range value 729) T n The pseudo-random generation result is calculated modulo the "Time range". This formula is provided as an example only. Other pseudo-random generation functions shared by all stations in the group can be used. Other input parameters can also be used; the key is to generate predictable results for all stations belonging to the group and from the AP. T n Value; and

[0151] - RefLink Offset is as defined in the previous step 202.

[0152] After determining the next GET, in step 205, the station starts a timer that expires at the start time of the next epoch.

[0153] Next, at step 206, the station calculates the next value for the CPE parameter. In the case of an AP, the AP calculates the next value for the CPE parameter of each non-AP station belonging to that group. In the case of a non-AP station, the non-AP station only calculates the value of its own CPE parameter. The generation of the CPE parameter value is beyond the scope of this disclosure, but... Figure 3b Formula 334 provides an example of a general formula for generating CPE parameters for a given non-AP station:

[0154] CPE-Param = PRF-M\L(PTK , “ERCM”, T n )

[0155] In this example, a pseudo-random generation function that generates M pseudo-random bits is used, and L bits (as shown by the M\L notation) are used to create the values ​​of all CPE parameters for a given non-AP station. The private key PTK is used to generate the CPE parameters for the given non-AP station. It is derived from PTK (KDK), which is a secret key created during association processing and known only to non-AP stations and APs. Other input parameters are the same as those used in Equation 333.

[0156] At step 208, the station stores the values ​​of all calculated CPE parameters in its memory. In the case of an AP, it stores the values ​​of all CPE parameters belonging to each non-AP station in that group. In some embodiments, the station also stores n and T as calculated in step 204. n The value, and stores the GET corresponding to the start time of the current epoch. n-1 The value (this value is used in a specific situation, for example, such as...) Figure 8c (as described in optional step 832).

[0157] Figure 2b Examples of steps performed in a non-AP station when starting a new individual epoch series are shown according to some embodiments of this disclosure.

[0158] As shown in the figure, the first step (step 210) aims to determine the individual epoch parameters. According to some embodiments, the non-AP station restores the values ​​of the individual epoch series parameters stored in its internal memory (e.g., during the setup of the individual epoch series). Note that these values ​​cannot be modified while the non-AP station is asleep.

[0159] Next, during step 214, the start time of the first volume epoch, represented as IET0, is determined. According to some embodiments, IET0 = IT0, where IT0 is determined via the volume epoch request and response frames (e.g., respectively). Figure 7c and Figure 7dThe start time field of the individual epoch request and response frames 730 and 740 (e.g., Figure 7c The start time field 732 in the memory is negotiated with the AP and stored in internal memory after successful negotiation with the AP (e.g., receiving an individual epoch response frame 740 with an error code 750 set to success).

[0160] Next, after the first IET is determined, in step 215, the station starts a timer that expires at the start time of the next body epoch.

[0161] Next, at step 216, the station calculates the next value of the CPE parameter. In the case of AP, the AP station calculates the next value of the CPE parameter for the non-AP station associated with the individual's epoch start time. In the case of non-AP stations, the non-AP station calculates its own CPE parameter value. The generation of CPE parameter values ​​is beyond the scope of this disclosure, but... Figure 4b Formula 434 provides an example of a general formula for generating CPE parameters for a given non-AP station:

[0162] CPE-Param = PRF-M\L(PTK “ERCM”, IT n )

[0163] In this example, a pseudo-random generation function that generates M pseudo-random bits is used, and L bits (as shown by the M\L notation) are used to create the values ​​of all CPE parameters for a given non-AP station. The private key PTK is used to generate the CPE parameters for the given non-AP station. It is derived from the PTK, which is a secret key created during association processing and known only to non-AP stations and APs. Other input parameters are... Figure 3b The input parameters used in formula 333 are the same.

[0164] Next, at step 218, the station stores the values ​​of all calculated CPE parameters in the memory. In the case of an AP, it stores the values ​​of all CPE parameters for the non-AP stations under consideration.

[0165] In some embodiments, if a non-AP STA (epoch initiator) requests individual epoch management, the non-AP STA requests (e.g., through the individual epoch request) Figure 7c The individual epoch request (730) negotiates the following epoch parameters with the AP:

[0166] Individual Epoch Interval: IEI;

[0167] The start time of the first physical era: IET0 (the precise time indicated by STA). T0=0), and the associated RefLink ID;

[0168] Maximum duration of an epoch (e.g., expressed in iterations): N;

[0169] N=0: Undetermined duration (associated lifetime);

[0170] N=1: A single execution of @MAC change;

[0171] N>1: The determined duration.

[0172] Note 1: The epoch parameters (IEI, IET0, N, and RefLink ID) are encrypted and not known to other STAs.

[0173] Note 2: For individual eras, IET0 = IT0.

[0174] Then, AP and non-AP STAs can calculate the reference time for future individual epochs.

[0175] n = [(current TSF – IET0) / IEI]

[0176] ITn+1 = IET0 + (n+1) × IEI

[0177] Before the next epoch reference time, both non-AP STA and AP calculate the future epoch start time and the associated CPE parameters of non-AP STA.

[0178] (CPE_PARAMn+1, ITn+1) = PRF-M\L(PTK , “ERCM”, ITn+1)

[0179] IETn+1=ITn+1 + ITn+1 + RefLink Offset

[0180] In these embodiments, the CPE parameters are calculated using a single PRF call by using the following as input parameters: the key derived from the PTK and the reference start time of the epoch.

[0181] Figure 3a Examples of group epoch start time sequences for non-AP station groups associated with the same AP station are shown according to some embodiments of this disclosure. Figure 3a and Figure 3b It describes how to perform epoch start boundary calculations for variable groups.

[0182] In this embodiment, the Group Era Start Time (GET) is based on a fixed frequency with finite pseudo-random variations.

[0183] In this embodiment, some reference times T0(300), T1(301) to T n (303) is defined and used to calculate the effective group epoch start time GET0(320), GET1(321) to GET n (323).

[0184] Reference time T occurs at regular intervals of group epoch interval (GEI) values ​​(in μs), starting from the first occurrence T0 (300) defined by AP. n The TSF counter value is defined as the reference link corresponding to the group epoch reference time number n.

[0185] In other words, Tn = the TSF counter value of the epoch reference time number n.

[0186] In some embodiments, a non-AP station is a multi-link device (MLD) associated with an AP multi-link device (MLD) via at least one link. In the case of an AP MLD, the reference link is a link selected by the AP among its active links, which is used as a reference to determine the TSF difference between different links.

[0187] The TSF counter may differ between two links of a given MLD STA: there may be a constant difference (TSF offset) between TSF values ​​of different links within the same MLD, but the clock drift between two links within the same MLD should be limited to its maximum value (set to 30 μs in the case of IEEE 802.11be revision). See reference... Figures 7a to 7d In more detail, these offsets can be communicated to non-AP stations using, for example, basic multilink information elements transmitted in beacons.

[0188] In these embodiments, the start times of the epochs of all non-AP STAs attached to a single non-AP MLD are time-aligned.

[0189] Non-Simultaneous Transmit and Receive (NSTR) mobile APs are a specific case where the AP cannot simultaneously transmit and receive on two different links. In this case, IEEE 802.11be revision precisely states that for NSTR mobile APs, the TSF offset presence field is always set to 0, but the drift between APs should be limited to 25 μs.

[0190] Example values ​​could be: GEI=10 minutes and Time range=2 minutes.

[0191] In the case of a single-link AP, the reference link is the only link provided by the AP, and the TSF offset is always 0.

[0192] exist Figure 3a In the example, based on each reference time T0 to T n Determine the start time of the group era from GET0 to GET n For reference Figure 8b More detailed description, according to Figure 3b Formula 300: GETn = Tn + Tn + RefLink Offset. (See reference) T0310, T1311 and T n 313 is, for example, a pseudo-random variation. T.

[0193] Figure 3b The following is shown for reference: Figure 2a The calculation of the group epoch start time at iteration n (GET) n ), reference time at iteration n (T) n ), iteration (n), pseudo-random change time (ΔT) at iteration n n Some examples of formulas for the value of the CPE parameter (CPE-Param) at iteration n.

[0194] Figure 4a An example of the individual epoch start time series of a single non-AP station associated with an AP station is shown. Figure 4a and Figure 4b It describes how to calculate the epoch boundary of individual variables.

[0195] In one embodiment, the Individual Era Start Time (IET) is based on a fixed frequency with finite pseudo-random variation.

[0196] In this embodiment, some reference times IT0 (400), T1 (401) to IT n (403) is defined and used to calculate the effective individual epoch start time IET0(420), IET1(421) to IET n (423).

[0197] The reference time IT occurs at regular intervals of Individual Era Interval (IEI) values ​​(in μs), and begins at the first occurrence of IT0 (400) defined during the negotiation period between the requesting non-AP station and the AP (as referenced). Figure 9b (As stated). Reference time IT n The TSF counter value is defined as the reference link corresponding to the individual epoch reference time number n.

[0198] In other words, ITn = the TSF counter value of the individual epoch reference time number n.

[0199] In some embodiments, a non-AP station is a multi-link device (MLD) associated with an AP multi-link device (MLD) via at least one link. In the case of an AP MLD, the reference link is a link selected by the AP among its active links, which is used as a reference to determine the TSF difference between different links.

[0200] For reference Figure 3a The TSF counter can be different between the two links of a given MLD STA: as... Figure 4a As shown, according to Figure 4b Formula 430 (IETn=ITn+ ITn + RefLink Offset), based on each reference time IT0 to IT n Determine the start time of the individual era from IET0 to IET n (as referenced) Figure 8c (as described). (See attached figures / reference numerals) IT0410 IT1411 and IT n 413 is, for example, a pseudo-random variation. IT.

[0201] Here it is observed that non-AP stations may need to change CPE parameters more frequently compared to the AP usage group epoch series.

[0202] Example values ​​could be: for non-AP sites, IEI = 3 minutes and Time range = 30 seconds.

[0203] Figure 4b The following is shown for reference: Figure 2b The calculation of the individual epoch start time (IET) at iteration n is described. n ), reference time at iteration n (IT) n ), iteration(n), pseudo-random change time at iteration n (ΔIT) n Some examples of formulas for the value of the CPE parameter (CPE-Param) at iteration n.

[0204] Figure 4c An example of the EDP epoch sequence for a single non-AP station, associated with an AP station based on the implementation, is shown. The figure illustrates an example of the EDP epoch timeline and describes the process for determining active and decommissioned EDP epochs.

[0205] AP MLD has an active EDP epoch associated with a given non-AP MLD.

[0206] Non-AP MLDs have one active EDP epoch.

[0207] An EDP epoch becomes active for a given non-AP MLD when the EDP epoch begins, and ends when another EDP epoch becomes active for the same non-AP MLD.

[0208] At the start of a new active EDP epoch, the preceding EDP epoch becomes the retired EDP epoch for a given time window (450, 451, 452) known as the EDP transition period.

[0209] Then, the retired EDP era is the EDP era that occurred immediately before the currently active EDP era.

[0210] exist Figure 4c In the example, EDP epoch 1 (460) becomes active at t1 and retires at t2 when EDP epoch 2 (461) subsequently becomes active.

[0211] During the EDP transition period, the FA parameters (i.e., EDP parameters) applied during the EDP retirement epoch remain valid.

[0212] Figure 4d This illustrates the sequential EDP epoch sequence based on the implementation and its associated EDP epoch start time t. n and transition period tp n Example. An EDP epoch begins with a transition period, during which the previous EDP parameters assigned to non-AP stations remain valid. The transition period ends at the end of the transition timeout interval or before the end of the transition timeout interval, after a successful transmission or retransmission initiated during the previous EDP epoch has been completed (whichever comes first).

[0213] refer to Figure 5 It describes the coexistence of group epochs and more frequent individual epochs for a given non-AP station.

[0214] Figure 5 This diagram illustrates an example of the coexistence of group epochs and individual epochs for non-AP stations associated with an AP station. In other words, the diagram shows an example of group and individual RCMs coexisting. In practice, it is possible for one or more non-AP stations to belong to a group epoch while still requiring the use of individual epochs (e.g., when a request originates from an application starting in a non-AP station).

[0215] In some embodiments, by default, 802.11bi non-AP STAs follow the group epoch.

[0216] If a non-AP STA negotiates its individual epoch with the AP, then the non-AP STA can:

[0217] Option 1: Follow only the individual era (ignore the group era);

[0218] Option 2: Follow both individual and group eras.

[0219] In option 2, additional rules are needed to avoid selecting individual era start times that are too close to the group era start time.

[0220] The group era should be given priority:

[0221] This is to ensure the "large-scale" effect of group changes;

[0222] This is because it is easier to cancel individual epoch changes (the effects on a single STA).

[0223] If the time between the start of the next individual and group eras is less than the TBD time (e.g., 1), the individual era is ignored.

[0224] |GETn - IETp| < 1s => IETp is ignored by both AP and non-AP STA, and non-AP STA only changes its CPE parameter at GETn.

[0225] refer to Figure 8c Optional step 832 describes such additional rules, and Figure 5 The effect of this optional step was emphasized.

[0226] In this example, a non-AP station belonging to the group associated with the group epoch series defined by the initial reference time T0 (300) initiates an individual epoch series with the first individual epoch start time at IET0 (420).

[0227] Based on this example, the individual epoch start time (IET) at iteration p is... p (423) Too close to the start time of the next epoch corresponding to iteration n (GET) n (323), that is, the difference between the start time of the individual era and the start time of the group era (expressed as...). T n,p (500) is below the predefined threshold. Therefore, according to Figure 8c Optional step 832 in the process, skipping the Individual Era Start Time (IET). p (423), and only at the start of the next epoch. n Change the CPE parameter at the beginning of (323).

[0228] Figure 6An example of an association of a multi-link device configured to implement at least some embodiments of the present disclosure is illustrated schematically.

[0229] As illustrated in the example, AP MLD 600 provides two links (link 1, labeled 651, and link 2, labeled 652) for association. Also according to this example, MLD STA1 611 is associated with AP MLD 600 and establishes two active links on link 1 and link 2, while MLD STA2 612, also associated with AP MLD 600, establishes only one link (link 2).

[0230] Figure 7a This indicates frame format 700, which shows the STA information field format of the basic multilink information element transmitted by an AP attached to an AP MLD as defined in IEEE 802.11be revision.

[0231] Field 710 contains the TSF offset between links, which indicates the TSF offset between the reported link and the link used to send the frame.

[0232] The IEEE 802.11be revision specifies:

[0233] - If the TSF offset field of the STA control field is set to 1, the TSF offset between links (Toffset) can be sent in the TSF offset subfield of the STA information field of the basic multilink element.

[0234] - The clock drift between two APs on a given AP MLD is limited to ±30μs.

[0235] - The Toffset between the TSF timer (TA) of the reported AP and the TSF timer (TB) of the reporting AP is encoded as a two's complement signed integer in 2μs units, and

[0236] - Toffset is calculated as Toffset = Floor ((TA – TB) / 2).

[0237] Figure 7b An example of an information element (IE) 720 containing parameters of a group epoch series according to some embodiments of the present disclosure is shown. The information element (IE) 720 conforms to section 9.4.2 of the IEEE 802.11-2020 standard, and fields 721 and 722, representing the element identifier and length of the IE, are fields defined in that standard specification.

[0238] The group ID field 728 may contain an identifier that allows access via, for example, in a beacon frame (e.g., Figure 9aIn the beacon frame 900, in the probe response frame, in the associated response frame, or in the group epoch indication frame (e.g., Figure 9a In the Group Epoch Indication Frame 910, a broadcast frame containing the IE with new parameter values ​​is sent to modify the Group Epoch series in the future.

[0239] Strategy field 723 can provide some information about the group epoch series, such as the following:

[0240] - Group epoch series are optional for receiving non-AP stations, meaning that the AP establishes the group epoch series, but non-AP stations can decide to ignore it. In this case, the non-AP station should follow the group epoch series until it successfully negotiates an individual group epoch series with an exclusive strategy;

[0241] - Group epoch series are mandatory for receiving non-AP stations, which means that non-AP stations should follow the group epoch series, but non-AP stations can also negotiate non-exclusive individual epoch series with APs;

[0242] - Group epoch series are exclusive to receiving non-AP stations, which means that non-AP stations must follow the group epoch series and cannot request individual epoch series;

[0243] - The group epoch series is global, meaning that all CPE parameters on different links of MLD non-AP sites change simultaneously; and

[0244] - The group epoch series is local, which indicates that only the CPE parameters associated with the link used to receive frames are changed.

[0245] For the sake of illustration, field policy 723 can be encoded as a bitmap, with each bit indicating one of the different parameters of the policy (optional / mandatory, exclusive / non-exclusive, global / local).

[0246] The start time field 724 indicates the reference time T0 of the epoch series (e.g., Figure 3a (Reference time 300).

[0247] The interval 725 indicates the Group Epoch Interval (GEI) of the Group Epoch Series.

[0248] The Duration field 726 indicates the duration of the epoch series. For illustration, a value of 0 in this field can indicate that there is no time limit for the series. The duration can be indicated in the number of iterations, in time units (TU) values, or in any other time-indicating unit.

[0249] In the case of a multi-link device, LinkId 727 indicates the link identifier of the link used as a time reference for the expression of reference time T0.

[0250] The time range 729 indicator can select pseudo-random variations. T (for example, Figure 3a Pseudo-random variations in T0310, T1311 or T n The range of values ​​for 313).

[0251] Figure 7c An example of a frame format for an individual epoch request frame 730 according to some embodiments of the present disclosure is shown.

[0252] Individual Epoch Request Frame 730 includes a header as defined in the IEEE 802.11 standard. Additionally, it includes a policy field 731, a start time field 732, an interval field 733, a duration field 734, and a time range field 735.

[0253] Policy field 731 indicates how a non-AP station intends to handle a requested individual epoch series regarding a potential existing group epoch series. The policy can provide one of the following information items:

[0254] - Exclusivity, which means that non-AP stations will only follow the individual era series regardless of the group era series, or

[0255] - Non-exclusive, which means that non-AP stations will follow both the requested individual epoch series and any group epoch series to which it belongs.

[0256] The start time 732 indication is also used as the first reference time IT0 (e.g., Figure 4a The time reference (reference time 400) is the start time of the first volume epoch in the series. The time reference can be the TSF counter on the link where a non-AP station sends request frames 730.

[0257] Interval 733 indicates the Individual Era Interval (IEI) of the requested Individual Era series.

[0258] Duration 734 indicates the duration of the epoch series. This duration can be indicated by the number of iterations, by a time unit (TU) value, or by any other unit of time. According to a particular embodiment, the following two values ​​have specific meanings:

[0259] - A value of 0 indicates that there is no time limit for this series, and

[0260] - A value of 1 indicates that the series contains only one iteration. This specific value allows a non-AP station to request a change to its CPE parameter at a specified time defined by the value of the start time field 732. After this change to the CPE parameter, the non-AP station follows the potential group epoch series of its group. The use of value 1 is particularly useful if a non-AP station must change its CPE parameter when requested by an upper layer (e.g., an application request).

[0261] The time range 735 indicator can select pseudo-random variations. T (for example, Figure 4a Pseudo-random variations in IT0410 IT1411 or IT n The range of values ​​for 413).

[0262] Figure 7d An example of a frame format for an individual epoch response frame 740 according to some embodiments of the present disclosure is shown.

[0263] The individual epoch response frame 740 includes a header as defined in the IEEE 802.11 standard. Additionally, it includes an error code field 750 and optionally includes a policy field 731, a start time field 732, an interval field 733, a duration field 734, and / or a time range field 735.

[0264] Error code field 750 contains the AP's response to the request to create an individual epoch series. If the AP rejects a request from a non-AP site, fields 731 through 735 may contain alternative proposals for creating an individual epoch series.

[0265] On the other hand, if the AP agrees to request the creation of an individual epoch series for a non-AP station, error code 750 should indicate success, and fields 731 to 735 may optionally be absent.

[0266] Figure 7e An example of a frame format for an epoch request frame 760 (enhanced data privacy) according to some embodiments of this disclosure is shown. Frame 760 has a format similar to... Figure 7c Frame 730 has similar fields. The same reference numerals are used for these fields. Compared to Frame 730, Frame 760 has an additional new Group ID field 768, which allows the requesting station to inform the responding station of the group ID that the requesting station wants to participate in.

[0267] Figure 7f An example of a frame format for an epoch response frame 770 (enhanced data privacy) according to some embodiments of this disclosure is shown. Frame 770 has a frame format with... Figure 7dFrame 740 has similar fields. The same reference numerals are used for these fields. Compared to Frame 740, Frame 770 has an additional new Group ID field 778 that indicates to the responding station which group ID was assigned to the requesting station.

[0268] Figure 7g Examples of information elements (IE) 780 containing parameters of an epoch series (individual or group) according to some embodiments of this disclosure are shown. In embodiments, the epoch series can be renamed as an EDP (Enhanced Data Privacy) epoch sequence. Information element 780 has parameters related to... Figure 7b Information element 720 has similar fields. The same reference numerals are used for these fields.

[0269] Information element (IE) 780 conforms to section 9.4.2 of the IEEE 802.11-2020 standard, and fields 721, 722, and 781, representing the element identifier, the length of the IE, and the element ID extension field, are fields defined in that standard specification.

[0270] The Group ID field 788 can contain an identifier that allows for future modifications to the epoch series. The Group ID field series is also used to distinguish between individual and group epoch sequences. For example, when the Group ID field is set to 0, the corresponding EDP epoch sequence is an individual EDP epoch sequence. Otherwise, the Group ID field identifies the group EDP epoch sequence.

[0271] Strategy field 783 can provide some information about the group epoch series, such as the following:

[0272] - The group EDP epoch sequence is optional for receiving non-AP stations, meaning that the AP establishes the group epoch sequence, but non-AP stations can decide to ignore it. In this case, non-AP stations should follow the group EDP epoch sequence until they successfully negotiate an individual EDP epoch sequence with an exclusive strategy;

[0273] - The group EDP epoch sequence is mandatory for receiving non-AP stations, which means that non-AP stations should follow the group EDP epoch sequence, but non-AP stations can also negotiate non-exclusive individual EDP epoch sequences with the AP.

[0274] - The group EDP epoch sequence is exclusive to receiving non-AP stations, which means that non-AP stations must follow the group EDP epoch sequence and cannot request individual EDP epoch sequences.

[0275] - The EDP epoch sequence is global, meaning that all CPE parameters on different links of MLD non-AP sites change simultaneously; and

[0276] - The EDP epoch sequence is local, which means that only the CPE parameters associated with the link used to receive frames are changed.

[0277] For the sake of illustration, field policy 783 can be encoded as a bitmap, with each bit indicating one of the different parameters of the policy (optional / mandatory, exclusive / non-exclusive, global / local).

[0278] The start time field 784 indicates the reference time T0 of the EDP epoch sequence (e.g., Figure 3a (Reference time 300 in the reference time). When the corresponding EDP epoch sequence parameter element is included in an EDP epoch sequence request frame sent by a non-AP STA, the start time field can be set to 0 to indicate a request to become a member of the group EDP epoch sequence identified by the group identifier field 788.

[0279] Interval 785 indicates the epoch interval (GEI) of the EDP epoch sequence.

[0280] The duration field 786 indicates the duration of the EDP epoch sequence. For illustrative purposes, a value of 0 for this field can indicate that there is no time limit for the sequence. The duration can be indicated in the number of iterations, in units of time (TU) values, or in any other time indication unit. In another embodiment, a special value of field 726 (e.g., the maximum value this field can take) can indicate that there is no time limit for the sequence. The duration can be indicated in the number of iterations, in multiples of units of time (TU) values, in beacon intervals, or in any other time indication unit. A special value of field 786 (e.g., 0) can indicate that the sender of the frame requests to leave the group. Alternatively or additionally, a special value of this field (e.g., 0) can indicate that the receiver of the frame must leave the group. This can be sent, for example, before canceling the group. Another special value (e.g., 1) can indicate a request for a change to the parameters (without establishing a sequence). In another embodiment, this field only supports special values, thereby reducing the required size of the field to, for example, 2 bits.

[0281] In the case of a multi-link device, LinkId 787 indicates the link identifier of the link used as a time reference for the expression of reference time T0.

[0282] The time range 789 indicator can select pseudo-random variations. T (for example, Figure 3a Pseudo-random variations in T0310, T1311 or T n The range of values ​​for 313).

[0283] Figure 8aExamples of steps performed in a non-AP station implementing some embodiments of this disclosure are shown when waking up after a sleep period.

[0284] Upon waking from a sleep period, a non-AP station must ensure that it is using the correct CPE parameter values; otherwise, it may discard frames dedicated to it or face rejection of frames it transmits to the AP. This is because several epochs may have passed during a long period, or the AP may have changed, for example, group epoch parameters.

[0285] During step 800, the non-AP station determines the latest group epoch parameters. This can be done by checking its internal memory or by waiting for at least one beacon (e.g., Figure 9a The reception of beacon 900 in the middle is used to recover the latest group epoch parameter information.

[0286] Next, during step 812, the non-AP station determines the current iteration number n of the group epoch series. Step 812 is similar to step 202, therefore, the non-AP station can use, for example... Figure 3b Formula 332 in the text:

[0287] n = [(current TSF –T0– RefLink Offset) / GEI]

[0288] in:

[0289] T0 and GEI are part of the epoch series parameters, and

[0290] RefLink Offset = The offset of the current link's TSF counter compared to the reference link (id RefLink ID), with a resolution of 2μs.

[0291] T0 is the value of the first reference time of the epoch on the reference link.

[0292] Note again that if no beacon is received on the current link (e.g., multi-link power-saving mode), it cannot be transmitted via TSF offset (e.g., Figure 7a The TSF offset (710) is read directly from the RefLink Offset. If the reference link selected by AP MLD 600 is Link 1 (e.g., ... Figure 6 As shown in the image, this is also the case.

[0293] In this case, the two TSF offset fields of the basic multi-link information element received on the reporting link can be used (e.g., Figure 7a The TSF offset (710) is used to approximate the RefLink Offset:

[0294] - RefLink TSF Offset field in the received beacon: TSF Offset RefLink = Floor((TSF RefLink –TSF Reporting ) / 2.

[0295] RefLink Offset = 2 × TSF Offset RefLink

[0296] = 2 × Floor ((TSF RefLink - TSF current ) / 2)

[0297] ≈ Floor ((TSF RefLink - TSF reporting ) / 2) – Floor ((TSF Current -TSF Reporting ) / 2)

[0298] ≈ 2 × (TSF Offset RefLink – TSF Offset current )

[0299] Additionally, during step 812, for example according to Figure 3b Formula 330 in the reference Figure 2a As described in step 204, but using the iteration number n determined in step 812 without incrementing it, to determine the start time of the current group epoch (GET). n That is, the start time of the current group epoch for iteration number n).

[0300] Next, at step 814, as Figure 2b As in step 210, the non-AP station restores the individual epoch series parameters stored in its internal memory (note that these values ​​cannot be modified during the non-AP station's sleep). If these values ​​are not empty (i.e., the individual epoch series has been set), the non-AP station, for example, applies the parameters during step 816. Figure 4b Formula 432 in the formula determines the current iteration number p of the individual epoch series. Formula 432 is very similar to the formula used in step 812 (except that the epoch series parameter corresponds to the individual epoch series). Formula 432 is as follows:

[0301] p = [(current TSF –IT0– RefLink Offset) / IEI]

[0302] IT0 corresponds to the start time of the first volume epoch in the series, and IEI corresponds to the individual epoch interval. These two values ​​are negotiated in the individual epoch series (as referenced). Figure 9b During the period described above, exchanges (e.g., in) Figure 7c or Figure 7d The individual epoch series parameters (exchanged in frames 730 or 740) are part of the Reflink Offset and current TSF (current TSF), which have the same meaning as in the previous step 812.

[0303] Next, during step 818, non-AP stations determine the values ​​of the current CPE parameters they should use. To do this, the group epoch start time (GET) is first determined. n ) and the start time of the individual era (IET) p Which of the following is the most recent occurrence? Then, for example, the value of the current CPE parameter to be applied is determined by applying step 206, which is used to calculate the CPE parameter based on the group epoch parameter value, or step 216, which is used to calculate the CPE parameter based on the individual epoch parameter value.

[0304] In some embodiments, the epoch begins with a transition period during which both the new and old CPE parameter values ​​can be used for a given non-AP station. In such embodiments, optional step 820 is performed to determine the value of the previous CPE parameter corresponding to the value of the old CPE parameter that may still be valid. This step can be performed by steps similar to steps 814 and 818 with respective iteration values ​​of n-1 and p-1.

[0305] Next, during step 820, GET is determined. n GET n-1 IET n and IET n-1 Which of the events most recently occurred before the time determined in step 818? Then, for example, according to step 206 or 216, the value of the associated CPE parameter is calculated for the corresponding number of iterations.

[0306] Finally, the determined value of the current CPE parameter is applied as the value of the new CPE parameter (step 850), and if possible, the value of the previous CPE parameter is applied as the value of the old CPE parameter.

[0307] Figure 8b Examples of steps performed in a station (AP station or non-AP station belonging to a group) implementing some embodiments of this disclosure are shown when the group epoch timer expires.

[0308] When the Group Era timer expires, it means that a new Group Era in the Group Era series is beginning.

[0309] At step 822, similar to step 820, the station is restored. Figure 2a or Figure 8b The values ​​of some parameters calculated in steps 204 and 206 (in previous iterations), including the value of the current iteration n and the reference time T. n (For example, Figure 3a The reference time (303) and the values ​​of all CPE parameters.

[0310] Next, similar to step 850, the recovered CPE parameter values ​​are applied at step 851. This step is beyond the scope of this disclosure but covers, for example, changes to the current MAC address of non-AP stations and obfuscation of PN or SN parameters. In some embodiments, the start of a new epoch consists of a transition period during which a set of old and new CPE parameter values ​​can be used. In such embodiments, the current CPE parameter value replaces the old CPE parameter value and is replaced by the previously calculated new CPE parameter value. In the case of AP stations, the CPE parameter values ​​are changed for each non-AP station belonging to that group.

[0311] Next, during step 204, the station calculates the start time of the next epoch in the epoch series. To do this, the station first restores the values ​​of the latest epoch series parameters stored in memory (as referenced). Figure 8a (as described in step 800), then as referenced Figure 2a As described in step 204, for example using Figure 3b Formula 330 in the formula calculates the start time of the next epoch. Formula 330 is read as follows:

[0312] GET n =T n + T n + RefLink Offset.

[0313] Next, during step 206, the station calculates the next value for the CPE parameter. In the case of an AP, the AP calculates the next value for the CPE parameter of each non-AP station belonging to that group. In the case of a non-AP station, the non-AP station only calculates the value of its own CPE parameter. The generation of the CPE parameter value is beyond the scope of this disclosure, but as stated above, in Figure 3b Formula 334 in the document provides the method for (as referenced) Figure 2a Example of a general formula for generating the values ​​of CPE parameters for a given non-AP station (described in step 206), formula 334 is read as follows:

[0314] CPE-Param = PRF-M\L(PTK , “ERCM”, Tn ).

[0315] Next, during step 208, the station stores the values ​​of all calculated CPE parameters in its memory. In the case of an AP station, it stores the values ​​of all CPE parameters belonging to each of the non-AP stations in that group. In some embodiments, the station also stores n and T as calculated in step 204. n The value, and stores the GET corresponding to the start time of the current epoch. n-1 The value (this value in) Figure 8c (Used in optional step 832).

[0316] Figure 8c Examples of steps performed in a station (AP station or non-AP station) implementing some embodiments of this disclosure are shown when an individual epoch timer expires.

[0317] When the Individual Era timer expires, it means that a new Individual Era in the Individual Era series is beginning for the associated non-AP station.

[0318] During the first step (step 830), the station is restored to its normal state. Figure 2b In step 214 or in Figure 8c In step 835 (in the previous iteration), and in Figure 2b or Figure 8c The values ​​of some parameters calculated in step 216 (in previous iterations) include the value of the current iteration n and the reference time IT. p The value (for example, Figure 4a The reference time 403 value) and the values ​​of all CPE parameters.

[0319] During optional step 832, the station determines whether the current individual epoch start time is too close to the start time of the previous or next set of epochs. This optional step ensures that non-AP stations will not change their CPE parameters too quickly to avoid overlapping transition periods for the same non-AP station, which would result in unstable behavior where the station supports more than one old and one new set of CPE parameter values. To this end, the station calculates the minimum of the following time differences: current IET p (exist Figure 4a and Figure 5 (marked as 423) and in Figure 2a and Figure 8b The next GET, stored in memory at step 208. n (exist Figure 3a and Figure 5 The time difference between (marked as 323) is expressed as T n,p (exist Figure 5 (marked as 500), and the current IETp With Figure 2a and Figure 8b Step 208 is stored in memory (or using...) Figure 3b Formula 330 in the previous GET) n-1 The time difference between them. If the difference exceeds a predefined threshold, there is no epoch conflict and step 821 is executed; otherwise, the value of the CPE parameter is not changed (i.e., step 821 is skipped) and step 835 is executed.

[0320] At step 821, the station applies the restored CPE parameters. This step is beyond the scope of this disclosure but covers, for example, changes to the current MAC address of a non-AP station and obfuscation of PN or SN parameters. In some embodiments, the start of a new epoch consists of a transition period during which a set of old and new CPE parameter values ​​can be used. In such embodiments, the value of the current CPE parameter replaces the value of the old CPE parameter and is then replaced by the value of the previously calculated new CPE parameter.

[0321] At step 835, the station calculates the next individual epoch start time (IET) for the individual epoch series. To do this, the station first restores the values ​​of the latest individual epoch series parameters stored in memory (as referenced). Figure 2b and Figure 8a (as described in step 814), then using, for example Figure 4b Formula 430 is used to calculate the start time of the next epoch. Formula 430 is read as follows:

[0322] IET n =IT n + IT n + RefLink Offset

[0323] in:

[0324] - n is the number of iterations incremented by 1 compared to the recovered value (i.e., n = n + 1). In some embodiments, the value of n is not determined based on the stored value, but rather using... Figure 4b Formula 432 in the text is calculated directly;

[0325] - IT n It is the reference time at iteration n, which can be, for example, using Figure 4b It is determined by one of the formulas 431 in [the original text]. In some embodiments, it is determined according to the following formula, benefiting from the calculation of the value of the CPE parameter during [the original text is missing]. Figure 2b or Figure 8c In step 218 (in the previous iteration), the previous value stored in memory is used to obtain the value IT. n :

[0326] IT n =IT n-1 + IEI,

[0327] In some embodiments, the initial reference time IT0 is used according to the following formula (e.g., Figure 4a The reference time (400) and iteration value n are used to calculate IT. n IT n =IT0 + (n × IEI);

[0328] - IT n It is the pseudo-random change time at iteration n. For the sake of illustration, IT n A shared pseudo-random generation function can be used to calculate this, taking input parameters from those shared between AP stations and non-AP stations, along with at least the reference time ITn. Figure 4b Formula 433 indicates the generation IT n An example:

[0329] IT n =PRF-128\64(PTK “ERCM”, IT n ) mod (Time range)

[0330] The PRF-128 function is defined as in the IEEE 802.11 series. In this example, the function generates 128 pseudo-random bits, and only retains the first 64 pseudo-random bits for generation. IT n (As shown in the 128\64 notation). In this example, the secret key PTK is used as the input to the function. It is derived from the PTK (a key generated when AP and non-AP stations are associated), and is then known only to non-AP stations and AP stations. The final input parameter "ERCM" is a context indicating that this generation is specifically used to enhance randomization and modify MAC address characteristics. Finally, to obtain time range values ​​(e.g., Figure 7c and Figure 7d The duration within the predefined duration range of the time range value 735. IT n The pseudo-random generation result is calculated modulo a time range value. This formula is provided as an example only; other pseudo-random generation functions shared by AP and non-AP stations can be used. Other input parameters can also be used; the key is to generate predictable results for both AP and non-AP stations. IT nvalue.

[0331] - RefLink Offset as Figure 8a As defined in step 812.

[0332] After determining the next IET, at step 215, the station starts a timer that expires at the start time of the next epoch.

[0333] Next, during step 216, the station calculates the next value for the CPE parameter. In the case of an AP station, the AP station calculates the next value for the CPE parameter of the non-AP station associated with that individual epoch start time. In the case of a non-AP station, the non-AP station calculates the value of its own CPE parameter. The generation of the CPE parameter values ​​is beyond the scope of this disclosure, but examples of a general formula for generating the value of the CPE parameter for a given non-AP station are provided. Figure 4b Formula 434 in the text is read as follows:

[0334] CPE-Param = PRF-M\L(PTK “ERCM”, IT n )

[0335] In this example, a pseudo-random generation function that generates M pseudo-random bits is used, and L bits (as shown by the M\L notation) are used to create the values ​​of all CPE parameters for a given non-AP station. The private key PTK is used to generate the CPE parameters for the given non-AP station. It is derived from the PTK, which is a secret key created during association processing and known only to non-AP stations and AP stations. Other input parameters are... Figure 3b The input parameters used in formula 333 are the same.

[0336] At step 218, the station stores the values ​​of all calculated CPE parameters in its memory. In the case of an AP station, it stores the values ​​of all CPE parameters for non-AP stations. In some embodiments, the station also stores n and T as calculated in step 835. n The value of .

[0337] In another embodiment, since the same function is used with the same input to generate... IT n Both CPE-Parameters and PRF function are used together, so step 216 is executed concurrently with step 835 by calling the PRF function only once. A general example of this function is... Figure 4b Formula 435 is described in the text, and it is read as follows:

[0338] (CPE-Param n , IT n = PRF-M\L(PTK) “ERCM”, IT n )

[0339] After this call, IT n It is calculated as modulo 735 of the time range value.

[0340] Figure 9a An example of a frame shown is transmitted from an AP station to one or more non-AP stations according to some embodiments of this disclosure to indicate parameters of a group epoch series. This process (referred to as group EDP epoch advertising) allows the AP MLD to provide the same set of EDP epoch parameters to one or more of its associated non-AP STAs.

[0341] In the first embodiment, the AP sends a beacon frame 900, which can be broadcast in plaintext or sent to one or more non-AP stations associated with the AP and encrypted.

[0342] In the second embodiment, the AP may send group epoch indication frames 910, 911, or 912 to non-AP stations or to a group of non-AP stations. In one embodiment, group epoch indication frames 910, 911, or 912 are dedicated protected action frames (910, 911, 912) used during group EDP epoch advertising processing. For group EDP epoch advertising, using dedicated protected action frames during group EDP epoch advertising processing of the AP MLD enables the provision of the same set of EDP epoch parameters to one or more of the associated non-AP STAs of the AP MLD.

[0343] Upon receiving one of these frames 900 or 910 through 912, the non-AP station stores the group epoch series parameters in its internal memory for future use.

[0344] Figure 9b An example of frame exchange between a non-AP station and its associated AP station according to some embodiments of this disclosure to request the creation of an individual epoch series is illustrated. This process, called the individual EDP epoch negotiation process, allows the negotiation of a set of EDP epoch parameters between a non-AP MLD and its associated AP MLD.

[0345] When a non-AP station is determined to require an Individual Era series, for example due to privacy requirements that differ from those offered by an AP station (typically due to frequency variations in CPE parameters), the non-AP station sends an Individual Era Request frame 930 to its associated AP station (e.g., according to...). Figure 7cIndividual epoch request frame 730). In the case of a multi-link device, this request is sent via one of the active links between the AP MLD and the non-AP MLD. The start time is evaluated compared to the TSF counter associated with that link (e.g., Figure 7c and Figure 7d The start time is 732). In response to the individual epoch request frame 930, the AP station can receive the individual epoch response frame 940 from the AP station (e.g., according to the start time 732). Figure 7d The individual epoch response frame 740, as described above, may include a protocol or alternative proposal for the creation of an individual epoch series.

[0346] In one embodiment, frames 930 and 940 are dedicated protected action frames during individual EDP epoch negotiation processing. For individual EDP epoch negotiation, using dedicated protected action frames during individual EDP epoch negotiation processing enables the negotiation of the EDP epoch parameter set between a non-AP MLD and its associated AP MLD.

[0347] Figure 9c An example is shown of frame exchange between a requesting station and a responding station according to some embodiments of this disclosure to request the creation of an EDP epoch sequence. For example... Figure 7e If the group ID field 788 is set to 0, the EDP epoch sequence is an individual EDP epoch sequence; otherwise, it is a group EDP epoch sequence. When the requesting station is a non-AP MLD, the responder is the AP MLD associated with the non-AP MLD. Conversely, when the requesting station is an AP MLD, the responder is a non-AP MLD. This process, known as the EDP epoch negotiation process, allows the negotiation of the EDP epoch parameter set between a non-AP MLD and its associated AP MLD.

[0348] When a requesting station determines that it needs an EDP epoch sequence, for example due to privacy requirements that differ from the privacy level provided by the BSS (typically due to frequency changes in CPE parameters), the requesting station sends an EDP epoch request frame 950 to the responding station (e.g., according to...). Figure 7e The EDP epoch request frame 760). In the case of a multi-link device, the request is sent via one of the active links between the requesting MLD and the responding MLD. The start time is evaluated compared to the TSF counter associated with that link (e.g., Figure 7c The start time in 732 or Figure 7e (732 in the original text). If the requesting station wants to join an already created group EDP sequence, the start time is set to 0. In response to EDP epoch request frame 950, the requesting station can receive EDP epoch response frame 960 from the requesting station (e.g., according to...). Figure 7fThe EDP epoch response frame 770, as described above, may include a protocol or alternative proposal for the creation of the EDP epoch sequence.

[0349] In one embodiment, frames 950 and 960 are dedicated protected action frames during EDP epoch negotiation processing. Using dedicated protected action frames during EDP epoch negotiation processing enables the negotiation of the EDP epoch parameter set between a non-AP MLD and its associated AP MLD.

[0350] In another embodiment, the requesting station is an EDP AP station, and the responding station is an EDP non-AP station. Upon receiving a message containing... Figure 7g When an EDP epoch sequence request frame is sent with EDP epoch sequence parameter element 780 (which has a group ID field that is not set to 0), the EDP non-AP STA sends an EDP epoch sequence response frame to acknowledge or not acknowledge the membership of the group EDP epoch sequence defined in the just received EDP epoch sequence request frame. The group identifier field of the EDP epoch sequence response frame is set to the same value as the group identifier field of the just received EDP epoch sequence request frame. Other fields of the EDP epoch sequence parameter element in the EDP epoch sequence response frame are reserved.

[0351] In another embodiment, the requesting station is an EDP non-AP station, and the responding station is an EDP AP station. When the EDP non-AP STA sends a message containing... Figure 7g When an EDP epoch sequence request frame is received with EDP epoch sequence parameter element 780 (which has a group ID field that is not set to 0), the EDP non-AP STA intends to revoke its membership to the group identified by the group identifier field. Upon receiving this EDP epoch sequence request frame, the EDP AP STA sends an EDP epoch sequence response frame to acknowledge or not acknowledge the EDP non-APSTA's revocation of the EDP epoch sequence defined in the just received EDP epoch sequence request frame.

[0352] Figure 10 An example of a communication device configured to implement at least some embodiments of the present disclosure is illustrated schematically. This communication device may correspond to reference [reference]. Figure 1 Any station described. The communication device designated 1000 may preferably be a device such as a microcomputer, workstation, or portable device. Communication device 1000 may include a communication bus 1013, which may be connected to:

[0353] - The central processing unit 1001, labeled as CPU, such as a processor, etc.;

[0354] - A memory 1003, labeled MEM, is used to store executable code of a method or method step according to embodiments of the present disclosure, and registers suitable for recording variables and parameters required to implement the method; and

[0355] - At least two communication interfaces 1002 and 1002' are connected to a wireless communication network, such as a communication network according to one of the IEEE 802.11 standard families, via a transmitting antenna and a receiving antenna 1004 and 1004', respectively.

[0356] Preferably, the communication bus 1013 can provide communication and interoperability between various elements included in or connected to the communication device 1000. The representation of the bus is not limiting, and in particular, the central processing unit is operable to instruct any element of the communication device 1000 to communicate directly or by means of another element of the communication device 1000.

[0357] The executable code can be stored in memory, which can be a read-only hard disk or a removable digital medium (e.g., a disk). According to an alternative variation, the executable code of the program can be received via interface 1002 or 1002' through a communication network and stored in memory 1003 of communication device 1000 before being executed.

[0358] In some embodiments, the communication device 1000 may be a programmable device that uses software to implement embodiments of the present disclosure. However, alternatively, some embodiments of the present disclosure may be implemented wholly or partially in hardware (e.g., in the form of an application-specific integrated circuit or ASIC).

[0359] The embodiments disclosed herein (one or more) can also be implemented by a computer that reads and executes computer-executable instructions (e.g., one or more programs) recorded on a storage medium (which may also be more fully referred to as a "non-transitory computer-readable storage medium") to perform the functions of one or more of the above embodiments and / or includes one or more circuits (e.g., application-specific integrated circuits (ASICs)) for performing the functions of one or more of the above embodiments, and by a method performed by a computer of the system or device, for example, reading and executing computer-executable instructions from a storage medium to perform the functions of one or more of the above embodiments and / or controlling one or more circuits to perform the functions of one or more of the above embodiments. The computer may include one or more processors (e.g., a central processing unit (CPU), a microprocessor unit (MPU)) and may include a network of separate computers or separate processors for reading and executing the computer-executable instructions. The computer-executable instructions may be provided to the computer, for example, from a network or a storage medium. Storage media may include one or more of the following: hard disk, random access memory (RAM), read-only memory (ROM), storage device for distributed computing systems, optical discs (such as compact discs (CDs), digital multifunction discs (DVDs), etc.), flash memory devices, and memory cards.

[0360] When interpreting the specification and its related claims, expressions such as “comprising,” “containing,” “incorporating,” “including,” “is,” and “having” shall be interpreted in a non-exclusive manner, meaning that they are understood to allow for the presence of other items or components not explicitly defined. References to the singular shall also be interpreted as references to the plural, and vice versa.

[0361] Those skilled in the art will readily understand that the various parameters disclosed in the specification can be modified and the various disclosed embodiments can be combined without departing from the scope of this disclosure.

Claims

1. A method for changing the value of at least one privacy parameter of at least one station in a station group, the method comprising: A reference time is obtained, which is obtained directly or indirectly based on an initial reference time and the time interval to be iteratively applied; Obtain pseudo-random numbers; as well as The time for modifying the value of the at least one privacy parameter is determined based on a reference time and a pseudo-random number.

2. The method according to claim 1, further comprising: The iteration number of the current iteration is obtained based on the initial reference time, the time interval, and the current time, and the reference time is also obtained based on the iteration number.

3. The method according to claim 1 or 2, wherein, The initial reference time and the time interval are obtained from another station in the station group, respectively, as the group initial reference time and the group time interval. The time at which the value of the at least one privacy parameter is to be modified is the group time at which the value of the at least one privacy parameter is to be modified. The method further includes: Obtain the initial reference time and individual time interval for each individual; An individual reference time is obtained, which is obtained directly or indirectly based on the individual's initial reference time and the individual's time interval; Obtain individual pseudo-random numbers; and The individual time at which the value of the at least one privacy parameter is to be modified is determined based on the obtained reference time and the obtained individual pseudo-random number.

4. The method according to claim 3, further comprising: The determined individual time is compared with at least one determined group time, wherein if the difference between the determined individual time and the at least one determined group time is less than a threshold, only one of the determined individual time and the at least one determined group time is selected to change the value of the at least one privacy parameter.

5. The method according to claim 3 or 4, further comprising: A request is transmitted to the other station to change the value of at least one privacy parameter of the at least one station, the request including at least the individual's initial reference time and the individual's time interval. Specifically, upon receiving a response to the request, the individual reference time is obtained and the individual time for which the value of the at least one privacy parameter is to be modified is determined.

6. The method according to claim 3 or 4, further comprising: A request is transmitted to the other station to change the value of at least one privacy parameter of the at least one non-access point. Specifically, upon receiving a response to the request, the individual reference time is obtained and the individual time for which the value of the at least one privacy parameter needs to be modified is determined. The response to the request includes at least the individual initial reference time and the individual time interval.

7. The method according to any one of claims 3 to 6, wherein, Together with the initial reference time and the time interval, a policy is received from the other station, wherein the individual time and / or the group time for changing the value of the at least one privacy parameter are selected based on the received policy.

8. The method according to claim 1, further comprising: A request is transmitted to another station in the station group to change the value of at least one privacy parameter of the at least one station, the request including at least the initial reference time and the time interval. Specifically, upon receiving a response to the request, the process includes obtaining the reference time and determining the time at which the value of the at least one privacy parameter needs to be modified.

9. The method according to claim 1, further comprising: A request is transmitted to another station in the station group to change the value of the at least one privacy parameter of the at least one station. Specifically, upon receiving a response to the request, the process includes obtaining the reference time and determining the time at which the value of the at least one privacy parameter needs to be modified. The response to the request includes at least the initial reference time and the time interval.

10. The method according to any one of claims 1 to 9, further comprising: A timer is started, wherein the timer expires at the time when the value of the at least one privacy parameter is to be modified.

11. The method according to any one of claims 1 to 10, further comprising: Calculate and store the values ​​of the at least one privacy parameter for the previous iteration, the current iteration, and / or the next iteration.

12. The method according to claim 11, wherein, The same pseudo-random function is used once to obtain the pseudo-random number and to calculate the value of the at least one privacy parameter.

13. The method according to claim 11 or 12, where claim 10 is referenced, wherein, When the timer expires, the stored value of the at least one privacy parameter is restored and applied.

14. The method according to claim 13, wherein, The value of the at least one privacy parameter that is recovered and applied is a value for the current iteration, and the method further includes: recovering and applying the value of the at least one privacy parameter for the iteration immediately preceding the current iteration within a given time period.

15. The method according to any one of claims 1 to 14, further comprising: The obtained time range is defined, and the pseudo-random numbers obtained belong to the obtained time range.

16. The method according to any one of claims 1 to 15, wherein, The at least one station is at least one non-access point station, i.e., at least one non-AP station, the station group includes access point stations, i.e. AP stations, and the at least one non-AP station is associated with the AP station.

17. The method according to claim 16, wherein, The non-AP station and the AP station are multi-link devices, i.e., MLDs, and the time for modifying the value of the at least one privacy parameter is also determined based on the time offset of the reference link.

18. The method according to any one of claims 1 to 17, wherein, The at least one privacy parameter is at least one client privacy enhancement parameter, i.e., at least one CPE parameter.

19. The method according to claim 18, wherein, The at least one CPE parameter includes a public identifier, which is a MAC address or an associated identifier, i.e., an AID.

20. A computer program product for a programmable device, the computer program product comprising a sequence of instructions configured to implement the steps of the method according to any one of claims 1 to 19 when loaded into and executed by the programmable device.

21. A non-transitory computer-readable storage medium storing instructions of a computer program for implementing the steps of the method according to any one of claims 1 to 19.

22. A communication apparatus comprising a processing unit configured to perform the steps of the method according to any one of claims 1 to 19.

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