Patent Description:
Wireless local area network (WLAN) communications are described in IEEE P802.11REVme_D1. <NUM>, Draft Standard for Information technology- Telecommunications and information exchange between systems Local and metropolitan area networks- Specific requirements, Part <NUM>: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) Specifications "IEEE P802.11REVme". The publication Privacy-preserving <NUM> Access-Point Discovery, XP58200438A, discloses <NUM> WLAN AP discovery protocol which supports fast discovery and hidden networks while preserving privacy. IEEE document <NUM>-<NUM>/0107r2 describes a set of requirements for initial privacy in an <NUM> system. <CIT> discloses methods and systems for MAC address randomization.

A selection of optional features of the invention is set out in the dependent claims.

The accompanying drawings, which are incorporated herein and form part of the specification, illustrate the presented disclosure and, together with the description, further provide timing associated with when the changes are expected, and provide new values (e.g., addresses) that enable the PE STA to maintain association and utilize wireless services accordingly. To receive a PE beacon, an associated PE STA uses a random ID from the PE beacon, and a PE AP ID to perform a checksum calculation. The result of the checksum calculation can be compared with a checksum ID from the PE beacon, and if the comparison yields a substantial match, then the PE STA can confirm (e.g., discover) the PE AP that transmitted the PE beacon.

Some embodiments include a PE station (STA) that can receive a PE beacon frame with a media access control (MAC) header that includes a first random identifier (ID) and a first checksum ID. The PE STA can determine that the first random ID and the first checksum ID satisfy configured PE beacon parameters, and process the PE beacon frame responsive to the determination.

In some embodiments, the MAC header includes an extension type and subtype corresponding to an encrypted PE beacon frame or a PE discovery beacon frame. In some embodiments, the MAC header also includes a broadcast address. In some examples, the first random ID comprises at least <NUM> octets (e.g., <NUM> or <NUM> octets. ) In some embodiments, the first random ID and the first checksum ID correspond to an affiliated PE access point (AP) of a PE AP multilink device (MLD). To identify the PE AP MLD, the PE STA can select an AP MLD ID of the PE AP MLD, determine a checksum value using the AP MLD ID and the first random ID, and determine whether the first checksum ID satisfies the checksum value.

In some embodiments, an encrypted change sequence number is adjacent to the MAC header in the PE beacon frame. The PE STA can determine whether the change sequence number is the same the change sequence number of a previous PE beacon frame, and terminate reception of one or more remaining portions of the PE beacon frame when the change sequence number has changed. The PE STA can associate with a PE AP, and determine whether one or more elements of a PE basic service set (BSS) corresponding to the PE AP will be updated. In some embodiments, the one or more elements of the PE BSS identifies a number of target beacon transmission times (TBTTs) until a second PE beacon frame including an update of the one or more elements is received.

In some embodiments, the PE beacon frame includes a non-encrypted reduced neighbor report (RNR) element that includes a second random ID, a second checksum ID, and a PE multiple basic service set ID (MBSSID) size corresponding to a first neighbor PE AP. The PE MBSSID size corresponds to a size of encrypted PE BSS information of the first neighbor PE AP. When the first neighbor PE AP is affiliated with a PE AP MLD, the encrypted PE BSS information includes a second RNR for maintaining one or more links of the PE AP MLD with at least one other neighbor PE AP affiliated with the PE AP MLD.

The PE STA can determine a target PE beacon transmission time (TPBTT) comprising a random time offset from a TBTT, where the TPBTT does not change a timing synchronization function (TSF) timer corresponding to a PE AP transmitting the PE beacon frame. The TPBTT can occur during a PE beacon randomization window duration that is based on a percentage of the TBTT.

Some embodiments include a PE AP that can configure a PE beacon frame with a MAC header that includes a first random identifier (ID) and a first checksum ID that correspond to the PE AP, where the MAC header includes an extension type and subtype corresponding to an encrypted PE beacon or a PE discovery beacon. The PE AP can transmit the PE beacon frame at a TPBTT. In some embodiments, the TPBTT is based at least in part on a random time offset from a TBTT, where the TPBTT does not change a TSF timer of the PE AP. In some embodiments, the PE AP is affiliated with a PE AP MLD. The PE beacon frame can include a non-encrypted RNR element that includes a second random ID, a second checksum ID, and a PE MBSSID size corresponding to a neighbor PE AP, where the neighbor PE AP is also affiliated with the PE AP MLD. The PE MBSSID size can correspond to a size of encrypted PE BSS information of the neighbor PE AP.

Further embodiments, features, and advantages of the present disclosure, as well as the structure and operation of the various embodiments of the present disclosure, are described in detail below with reference to the accompanying drawings.

The accompanying drawings, which are incorporated herein and form part of the specification, illustrate the presented disclosure and, together with the description, further serve to explain the principles of the disclosure and enable a person of skill in the relevant art(s) to make and use the disclosure.

The presented disclosure is described with reference to the accompanying drawings. In the drawings, generally, like reference numbers indicate identical or functionally similar elements.

Some embodiments include a system, apparatus, article of manufacture, method, and/or computer program product and/or combinations and sub-combinations thereof, for privacy enhanced (PE) beacon frames. Some embodiments include a PE beacon frame with a media access control (MAC) header that includes a combination of an extension type field and subtype field of that enables a receiver to determine that the PE beacon frame is an encrypted PE beacon frame or a PE discovery beacon frame. The MAC header of the PE beacon frame can include a random identifier (ID) and a checksum ID that enable a PE station (STA) to identify the corresponding PE access point (AP) that transmitted the PE beacon frame. Some embodiments include fields for an encrypted PE beacon frame as well as a PE discovery beacon frame. Some embodiments include PE beacon transmission-period randomization for encrypted PE beacon frames and unsolicited PE discovery beacon frames.

Privacy in wireless networks (e.g., a basic service set (BSS)) is beneficial for many BSS types including but not limited to: a mobile access point (AP), an AP in a vehicle, a residential private network, a mesh backbone network, an Internet of Things (IoT) network, or a dedicated network (e.g., hospital, company network, hospital, government agency, public safety, etc.) A privacy enhanced (PE) BSS includes privacy enhancements for PE APs and associated PE stations (STAs). A PE BSS is not backward compatible with legacy STAs. Previously authenticated, associated, or preconfigured PE STAs can discover, authenticate, and associate with a PE BSS (e.g., with a PE AP that provides a PE BSS. ) Management frames are encrypted and most control frames are obfuscated or encrypted. Physical layer protocol data units (PPDUs) and MAC Protocol Data Units (MPDUs) transmitted in a PE BSS can be optimized to not include personally identifiable information (PII) and/or personally correlated information (PCI). PE BSSs are included in wireless local area network (WLAN) ecosystems.

<FIG> illustrates example system <NUM> supporting PE beacon frames, in accordance with some embodiments of the disclosure. System <NUM> includes physical AP <NUM> in a channel with two BSSs: legacy AP <NUM> and PE AP <NUM>. Legacy AP <NUM> provides a legacy BSS (e.g., with service set identifier (SSID) called "Coffee Shop") that does not provide any privacy enhancements to associated legacy devices like legacy STA <NUM>. In contrast, PE AP <NUM> provides a PE BSS (e.g., PE SSID named "PE Coffee Shop") that provides privacy enhancements to PE stations like PE STA <NUM>. System <NUM> also includes PE AP <NUM> that can provide a different PE BSS (e.g., PE SSID called "Sarah Knight's car") that provides privacy enhancements to PE stations like PE STA <NUM>. Physical AP <NUM> and PE AP <NUM> can access network <NUM>.

Legacy STA <NUM>, PE STA <NUM>, and/or PE STA <NUM> can be electronic devices that may include but are not limited to a cellular phone, a smart phone, a tablet, a personal digital assistant (PDA), or a laptop. Network <NUM> may include but is not limited to, any of or any combination of local area networks (LANs), metropolitan area networks (MANs), wireless local area networks (WLANs), and/or the Internet. In some embodiments, PE AP <NUM> may be a multilink device (MLD), where PE AP MLD <NUM> may include multiple APs, each AP including a corresponding radio transceiver that operates independently from the other radio transceivers. Each PE AP of PE AP MLD <NUM> may correspond to a particular different link. For example, a first PE AP can communicate via <NUM> link, a second PE AP can communicate via <NUM> link, and a third PE AP can communicate via <NUM> link.

<FIG> illustrates a block diagram of an example wireless system supporting PE beacon frames, according to some embodiments of the disclosure. For explanation purposes and not a limitation, <FIG> may be described with reference to elements from <FIG>. For example, system <NUM> may be any of the electronic devices: AP <NUM>, PE AP <NUM>, PE AP <NUM>, PE STA <NUM>, and/or PE STA <NUM> of system <NUM>. System <NUM> includes one or more processors <NUM>, transceiver(s) <NUM>, communication interface <NUM>, communication infrastructure <NUM>, memory <NUM>, and antenna <NUM>. Memory <NUM> may include random access memory (RAM) and/or cache, and may include control logic (e.g., computer instructions) and/or data. One or more processors <NUM> can execute the instructions stored in memory <NUM> to perform operations enabling wireless system <NUM> to transmit and receive wireless communications supporting PE beacon frames described herein. In some embodiments, one or more processors <NUM> can be "hard coded" to perform the functions herein. Transceiver(s) <NUM> transmits and receives wireless communications signals including wireless communications supporting PE beacon frames according to some embodiments, and may be coupled to one or more antennas <NUM> (e.g., 290a, 290b). In some embodiments, a transceiver 270a (not shown) may be coupled to antenna 290a and different transceiver 270b (not shown) can be coupled to antenna 290b. Communication interface <NUM> allows system <NUM> to communicate with other devices that may be wired and/or wireless. Communication infrastructure <NUM> may be a bus. Antenna <NUM> may include one or more antennas that may be the same or different types.

<FIG> illustrates example <NUM> of broadcast probe/query mechanisms, according to some embodiments of the disclosure. For explanation purposes and not a limitation, <FIG> may be described with reference to elements from other figures in the disclosure. For example, legacy AP <NUM>, PE AP <NUM>, PE AP <NUM>, PE STA <NUM>, and/or PE STA <NUM> of system <NUM> may correspond to legacy AP <NUM>, PE AP <NUM>, PE AP <NUM>, PE STA <NUM>, and/or PE <NUM> of system <NUM>, respectively. PE STA <NUM> can actively scan for available PE BSSs. For example, a PE STA can transmit a broadcast or directed Probe Request frame to request responses from a legacy AP or a PE AP. As shown in example <NUM>, PE STA <NUM> can transmit broadcast probe request <NUM> to PE AP <NUM>. In response, PE AP <NUM> can respond with a broadcast PE beacon frame <NUM> that can be an encrypted PE beacon frame or a PE discovery beacon frame. If the broadcast PE beacon frame <NUM> includes PE BSS information of multiple PE BSSs, then broadcast PE beacon frame <NUM> is a PE discovery beacon frame.

A PE STA can transmit a broadcast or directed PE Query Request frame to request responses from PE APs that provide PE BSSs. If a unicast PE Query Request is addressed to an associated PE AP (and corresponding PE BSS) the unicast PE Query Request is encrypted. A broadcast PE Query Request is transmitted unencrypted. For example, PE STA <NUM> can transmit broadcast PE Query request <NUM> unencrypted to PE AP <NUM>. In response, PE AP <NUM> can respond with broadcast PE beacon frame <NUM> that can be an encrypted PE beacon frame or a PE discovery beacon frame. When broadcast PE beacon frame <NUM> is a PE discovery beacon frame, broadcast PE beacon frame <NUM> includes PE BSS information of multiple PE BSSs corresponding to PE AP <NUM>. In some embodiments an extension type and subtype value in a frame control field of a MAC header of broadcast PE beacon frame <NUM> or <NUM> can enable a PE STA to detect an encrypted PE beacon frame or a PE discovery beacon frame.

<FIG> illustrate example fields for PE beacon frame type detection, according to some embodiments of the disclosure. For explanation purposes and not a limitation, <FIG> may be described with reference to elements from other figures in the disclosure.

For example, a type and subtype combination at row <NUM> of <FIG> can be included in MAC header <NUM> of <FIG>, MAC header <NUM> of <FIG>, and MAC header <NUM> of <FIG> below. Example <NUM> shows a management frame format that includes a MAC header, a frame body, and a frame check sequence field. Fields within the MAC header are not encrypted, and can include but are not limited to the following fields: frame control <NUM>, address <NUM><NUM>, address <NUM><NUM>, and address <NUM><NUM>. Frame control <NUM> is shown in more detail in example <NUM> of <FIG>. Example <NUM> can include but is not limited to type <NUM> and subtype <NUM>. Example values of type <NUM> and subtype <NUM> are shown in example <NUM> of <FIG>. Type <NUM> is used to detect whether the frame is a data, control, or management frame. Subtype <NUM> defines more fine grained content of the MPDU.

Some embodiments utilize a combination of type <NUM> and subtype <NUM> values to modify the structure of a MAC header to enable a PE STA to detect and determine a type of PE beacon frame. For example, when a PE beacon frame is received (e.g., an encrypted PE beacon frame in example <NUM> of <FIG> or a PE discovery beacon frame in example <NUM> of <FIG>), a receiver (e.g., PE STA) can determine based on a combination of type <NUM> and subtype <NUM> values in the respective MAC header fields, whether the receiver can decrypt the PE beacon frame. In some embodiments, type and subtype values shown as row <NUM> of example <NUM> of <FIG> may be used to detect and determine a PE beacon frame type. As an example, when type <NUM> = '<NUM>' and subtype <NUM> = '<NUM>' the PE beacon frame can be identified as an encrypted PE beacon frame. In another example, when type <NUM> = '<NUM>' and subtype <NUM> = '<NUM>' the PE beacon frame can be identified as a PE discovery beacon frame. The combinations of type <NUM> and subtype <NUM> corresponding to PE beacon frames, can affect the following fields of example <NUM>: address <NUM><NUM>, address <NUM><NUM>, and address <NUM><NUM> as shown in Table <NUM> below.

As shown in Table <NUM>, when MAC Header <NUM> in example <NUM> of <FIG> includes a combination of type <NUM> and subtype <NUM> corresponding to an encrypted PE beacon frame, or when a MAC Header <NUM> in example <NUM> of <FIG> includes a combination of type <NUM> and subtype <NUM> corresponding to a PE discovery beacon frame, address <NUM><NUM> and address <NUM><NUM> can include corresponding random ID and checksum ID values. In some embodiments, MAC Header <NUM> in example <NUM> of <FIG> includes a combination of type <NUM> and subtype <NUM> corresponding to a discovery beacon frame, and address <NUM><NUM> and address <NUM><NUM> can include corresponding random ID and checksum ID values. In other words, the address fields in MAC header <NUM>, MAC header <NUM>, and/or MAC header <NUM> of respective PE beacon frame formats and discovery beacon format can include a corresponding random ID and checksum ID. In some embodiments address <NUM> includes a broadcast address and each of the address fields (address <NUM><NUM>, address <NUM><NUM> and address <NUM><NUM>) are <NUM> octets in length.

The PE AP changes both the random ID and the checksum ID periodically to protect the identity of the PE AP. In some embodiments, the random ID and checksum ID may be additional fields added to the MAC header in example <NUM> before the frame body field. In some embodiments, the length of the random ID and checksum ID fields can vary.

<FIG> illustrate examples <NUM> and <NUM> of implementations for random IDs and checksum IDs, according to some embodiments of the disclosure. For explanation purposes and not a limitation, <FIG> may be described with reference to elements from other figures in the disclosure. For example, A1 <NUM>, A2, and A3 <NUM> of <FIG> may correspond to address fields address <NUM><NUM>, address <NUM><NUM>, and address <NUM><NUM> of <FIG>. Examples <NUM> and <NUM> illustrate how the three address fields can support random IDs and checksum IDs that are larger than <NUM> octets. For example, example <NUM> includes a <NUM> octet random ID <NUM> and <NUM> octet checksum ID <NUM>. Thus, A1 <NUM> and A2 <NUM> (e.g., the first <NUM> octets of A2) fields may be used to carry random ID <NUM>. A2 <NUM> (the last <NUM> octets of A2) combined with A3 <NUM> may be used to carry checksum ID <NUM>. Example <NUM> illustrates how the three address fields can be divided to support <NUM> octet random ID <NUM> and <NUM> octet checksum ID <NUM>. For example, A1 <NUM> and A2 <NUM> (e.g., the first <NUM> octets of A2) fields may be used to carry random ID <NUM>. A2 <NUM> (the last <NUM> octets of A2) combined with A3 <NUM> may be used to carry checksum ID <NUM>. The A2 <NUM> (the middle remaining <NUM> octets of A2) may be a reserved field, reserved <NUM>.

Returning to the last column of Table <NUM>, PE group frames may be transmitted by a PE AP. The MAC headers of PE beacon frames are different from other group frames transmitted by a PE AP. For example, a PE AP can configure group address set(s): transmitter Over the Air (OTA) MAC address and offsets for a Group address sequence number (SN) and/or packet number (PN).

<FIG> illustrates example <NUM> of PE AP identification from a PE beacon frame, according to some embodiments of the disclosure. For explanation purposes and not a limitation, <FIG> may be described with reference to elements from other figures in the disclosure. For example, PE AP MLD <NUM>, PE AP <NUM>, PE AP <NUM>, PE AP <NUM>, and/or PE STA <NUM> may be a system <NUM> of <FIG>. PE AP MLD <NUM> includes an identifier, AP MLD ID <NUM>, and PE AP MLD <NUM> includes <NUM> affiliated PE APs <NUM>, <NUM>, and <NUM>. Each affiliated PE AP (e.g., PE AP <NUM>, PE AP <NUM>, and PE AP <NUM>) in PE AP MLD <NUM> selects a different random ID value (e.g., random ID <NUM> is different than random ID <NUM> and random ID <NUM>). PE STA <NUM> may not be a MLD. PE STA <NUM> can be configured with identifier, AP MLD ID <NUM>, for PE AP MLD <NUM>.

PE STA <NUM> that is configured with the identifier, AP MLD ID <NUM>, for PE AP MLD <NUM> can discover PE AP MLD <NUM> from any PE beacon frame transmitted by an affiliated PE AP (e.g., PE AP <NUM>, PE AP <NUM>, and PE AP <NUM>). Other PE STAs that do not know AP MLD ID <NUM> (e.g., are not provisioned with AP MLD ID <NUM>) will expect that PE AP <NUM>, PE AP <NUM>, and/or PE AP <NUM> are not related to each other (e.g., not affiliated with AP MLD <NUM>). PE STA <NUM> can select AP MLD ID <NUM>, and can receive a PE beacon frame from any affiliated PE AP (e.g., PE AP <NUM>, PE AP <NUM>, and PE AP <NUM>). PE STA <NUM> can use the received random ID (e.g., random ID <NUM> from PE AP <NUM>) and AP MLD ID <NUM> to calculate a checksum ID. PE STA <NUM> can compare the calculated checksum value with checksum ID <NUM> received in the PE beacon frame. If the calculated checksum value substantially matches checksum ID2, PE STA <NUM> can verify the identity of PE AP <NUM>. In other words, PE STA <NUM> determines that PE AP <NUM> affiliated with AP MLD <NUM> has been discovered. In some embodiments the checksum used in the comparison is a previously stored value.

In some embodiments, for an <NUM> octet random ID, the calculated checksum value can be determined using a Hash Message Authentication Code (HMAC)-SHA and Address Resolution Key (ARK) functions shown below: <MAT> where.

In some embodiments, a PE STA stores information for PE APs and corresponding PE BSSs. A PE STA stores many PE AP parameters as shown in Table <NUM>.

Based on the stored information in Table <NUM>, a PE STA may select to authenticate with the PE BSS. In some embodiments, the STA may select to continue to setup pre-association security to obtain more information on the PE AP. In some embodiments, the PE AP ARK is used to detect the identification of the PE AP (e.g., this key is long term AP key that may be used in AP MLD ID calculation. ) The BIGTK key1 may be short term key to protect the payload of the Beacon frame. The BIGTK key2 may be long term key to calculate integrity check sum for a PE discovery beacon (e.g., a PE discovery beacon MME calculation. ) In some embodiments a salt for target PE beacon transmission time (TPBTT) may be stored by a PE STA (see <FIG>.

PE beacon frames may have a separate sequence number (SN) and/or packet number (PN) counter that are increased when a PE AP transmits a PE beacon frame. The PN and SN can be used for PE beacon payload encryption. Examples for PE beacon frame protection are shown below in Table <NUM>:.

<FIG> illustrates example <NUM> of an encrypted PE beacon frame format, according to some embodiments of the disclosure. For explanation purposes and not a limitation, <FIG> may be described with reference to elements from other figures in the disclosure. For example, example <NUM> may be included in broadcast PE beacon frame <NUM> transmitted from PE AP <NUM> and/or broadcast PE beacon frame <NUM> transmitted by PE AP <NUM> of <FIG>. PE beacons contain minimal information to maintain associations. The encrypted PE beacon frame format of example <NUM> can include MAC header <NUM>, change sequence number <NUM>, timing synchronization function (TSF) <NUM>, beacon update <NUM>, traffic indication map (TIM) <NUM>, reduced neighbor report (RNR) <NUM> and optional elements <NUM>. Note that the following fields are transmitted encrypted: change sequence number <NUM>, TSF <NUM>, beacon update <NUM>, TIM <NUM>, and/or RNR <NUM>.

The fields of the encrypted PE beacon frame format of example <NUM> are shown below in Table <NUM>.

In some embodiments, change sequence number <NUM> is located adjacent to and processed subsequent to MAC header <NUM> being processed. Change sequence number <NUM> signals to a PE STA whether any PE BSS parameters of a PE BSS provided by a PE AP (e.g., PE AP <NUM> or PE AP <NUM>) have changed or will change in the future. For example, a value of change sequence number <NUM> can be increased (e.g., by +<NUM>) if a BSS parameter has changed or will change. Thus, a PE STA (e.g., PE STA <NUM> or PE STA <NUM>) that receives the encrypted PE beacon frame of example <NUM> and decrypts change sequence number <NUM>, can determine whether any BSS parameters of the corresponding PE BSS have changed or will change. If for example, no BSS parameters have changed, then if the PE STA is not interested in any buffered downlink (DL) packets, the PE STA can terminate further reception of the encrypted PE beacon frame of example <NUM>. This early termination of the encrypted PE beacon frame can save PE STA resources (e.g., battery power) and the PE STA can for example, return to a sleep or doze state.

<FIG> illustrate examples of encrypted reduced neighbor report (RNR) element fields in an encrypted PE beacon format, according to some embodiments of the disclosure. For explanation purposes and not a limitation, <FIG> may be described with reference to elements from other figures in the disclosure. For example, RNR element <NUM> of <FIG> may correspond to RNR <NUM> of <FIG>. For example, RNR element <NUM> can include content for affiliated PE APs of a PE AP MLD, and encrypted portions of multiple BSSID (MBSSID) PE information.

Example <NUM> of <FIG> includes RNR element <NUM> that includes one or more neighbor AP information fields (e.g., neighbor AP info <NUM>. ) Since RNR element <NUM> is encrypted transmitted, RNR element <NUM> may utilize the legacy RNR format in the encrypted PE beacon frame format. Accordingly, neighbor AP info <NUM> includes target beacon transmission time (TBTT) info header <NUM> as well as TBTT info <NUM>. TBTT info <NUM> field includes BSS parameters <NUM> and MLD parameters <NUM>. Assume for example, a PE AP MLD includes <NUM> affiliated PE APs and the first PE AP transmitted the encrypted PE beacon frame of example <NUM>. The MLD ID field can be generated by the reporting first PE AP to identify the list of reported PE APs affiliated to the same PE AP MLD. The Link ID field indicates the link identifier of the reporting first PE AP within the PE AP MLD to which the reporting first PE AP is affiliated (e.g., the first PE AP of the PE AP MLD).

<FIG> illustrates an example of beacon update <NUM>, according to some embodiments of the disclosure. For explanation purposes and not a limitation, <FIG> may be described with reference to elements from other figures in the disclosure. For example, beacon update <NUM> is included in encrypted PE beacon frame example <NUM> of <FIG>. Some embodiments enable a PE AP to use beacon update <NUM> to inform an associated PE STA that changes to one or more PE BSS parameters are forthcoming, when the changes are coming, and any corresponding new values. Thus, an associated PE STA can timely adjust stored information to receive PE beacon frames with the updated information, and thus maintain the association with the PE AP.

For example, when change sequence number <NUM> of <FIG> indicates that a BSS parameter has changed or will change, the changes are indicated in beacon update <NUM>. As shown in <FIG>, beacon update <NUM> can include change information <NUM> and other elements <NUM>. Change information <NUM> can include beacon change mode (BCM) <NUM> and group address set change (GSC) <NUM> as shown below in Table <NUM> and Table <NUM>, respectively.

The values of BCM and/or GSC affect the information that is included in other elements <NUM> as shown in Table <NUM>.

<FIG> illustrates example <NUM> of a discovery beacon, according to some embodiments of the disclosure. Example <NUM> can include MAC header <NUM>, country/transmission power envelope <NUM>, reduced neighbor report (RNR) <NUM>, and Management Message Integrity Check (MIC) Element (MME) <NUM>. An AP (e.g., AP <NUM> or a PE AP) can send a discovery beacon to advertise PE BSSs. As described above, in some embodiments, MAC header <NUM> can include an extension type (e.g., <NUM>) and a subtype (e.g., <NUM>) that enables a PE STA to identify the discovery beacon (e.g., using random ID and checksum ID). The fields of example <NUM> are described below in Table <NUM>. In some embodiments, STAs may ignore MME <NUM>, if they do not have Beacon Integrity Group Transient Key (BIGTK) set with the transmitting AP. MME <NUM> is a hash check sum that may be used to detect integrity of the discovery beacon. If the MME calculated from the PE beacon frame content matches with the MME transmitted in the PE beacon frame, then the receiver knows that non-encrypted parts of the PE beacon frame has not been changed by an attacker.

<FIG> illustrates example <NUM> of a PE discovery beacon frame format with PE BSS information of multiple PE BSSs, according to some embodiments of the disclosure. For explanation purposes and not a limitation, <FIG> may be described with reference to elements from other figures in the disclosure. For example, PE discovery beacon frame format of example <NUM> may correspond to broadcast PE beacon frame <NUM> or broadcast PE beacon frame <NUM> of <FIG>. A problem with example <NUM> of <FIG> is that if RNR <NUM> includes two or more PE BSSs, an attacker may be able to track the discover beacon transmitter since RNR <NUM> is transmitted non-encrypted. In the encrypted PE beacon frame of example <NUM>, RNR <NUM> is encrypted when transmitted via a single PE BSS. Encrypted PE beacon frame tracking is complicated, because only MAC header <NUM> is not protected (e.g., not encrypted) and the relevant field values, like the random ID and checksum ID may be changed. Also the PE AP may change TSF more easily with single PE BSS.

PE discovery beacon frame of example <NUM> can include MAC header <NUM>, country/TX power envelope <NUM>, PE RNR <NUM>, multiple PE BSSID elements <NUM>, and MME <NUM>. Country/TX power envelope <NUM> and MME <NUM> may correspond to country/TX power envelope <NUM> and MME <NUM> of <FIG>. In some embodiments, integrity protection may have a separate key, for instance BIGTK Key <NUM>, that is provided to associated PE STAs. If the integrity key is not known, the PE STAs ignore MME <NUM>.

As described above, MAC header <NUM> may include a type and subtype that allows a PE STA to determine that a PE beacon frame is a PE discovery beacon frame. In addition, MAC header <NUM> may include a corresponding random ID and checksum ID to allow a receiver (e.g., a PE STA) to discover the PE AP transmitting a PE discovery beacon frame of example <NUM>.

In some embodiments, PE RNR <NUM> is a non-encrypted element that can include information for legacy BSSs and PE BSSs in the same channel or other channels, as well as corresponding sizes for PE BSS Specific Info subelements (e.g., for each PE BSS, a corresponding size of PE BSS specific info <NUM>-<NUM> through <NUM>-m are included in the order in which the TBTT Info <NUM> is included in the RNR element).

<FIG> illustrate examples of PE RNR <NUM> element fields of a PE discovery beacon that are not encrypted, according to some embodiments of the disclosure. For explanation purposes and not a limitation, <FIG> may be described with reference to elements from other figures in the disclosure. For example, PE RNR element <NUM> of <FIG> can be the same as PE RNR <NUM> of <FIG>. PE RNR element <NUM> can include neighbor legacy AP information and neighbor PE AP information where the neighbor legacy AP and neighbor PE AP are in the same channel. In example <NUM>, neighbor AP info <NUM> corresponds to a neighbor PE AP. Neighbor AP info <NUM> can include TBTT info header <NUM> and TBTT info <NUM>. TBTT info header <NUM> is shown in <FIG>. In some embodiments, TBTT info <NUM> of <FIG> includes random ID <NUM>, checksum ID <NUM>, and PE MBSSID size <NUM>. Random ID <NUM> and checksum ID <NUM> can be of a size (e.g., <NUM>-<NUM> octets) as described above in Table 1Table <NUM> and regarding <FIG>. PE MBSSID size <NUM> describes a size of a corresponding PE BSS specific info (e.g., PE BSS specific info <NUM>-<NUM>) of <FIG>. A PE STA that receives PE RNR <NUM> that is non-encrypted in transmission can use random ID <NUM> and checksum ID <NUM> to discover a corresponding neighboring PE AP (of the PE AP transmitting the PE discovery beacon of example <NUM>) as described above. Further, the PE STA can use PE MBSSID size <NUM> to obtain encrypted information specific to the PE BSS corresponding to the neighbor AP info <NUM>.

Returning to <FIG>, the encrypted information of a PE BSS Specific Info <NUM> of example <NUM> are described below in Table <NUM>.

In some embodiments, the beacon update elements as shown in Table <NUM> can include elements of beacon update <NUM> (e.g., a beacon update control field) of <FIG>, also shown in Table <NUM> and Table <NUM>. The beacon update elements provide information of the possible changes in the PE beacon frame content or transmission timing. The respective elements are targeted for PE STAs to be able to receive PE beacons with minimum power consumption, (e.g., the receivers may minimize the channel listening and calculations in PE beacon reception.

<FIG> illustrates example <NUM> of a legacy beacon, according to some embodiments of the disclosure. An AP can transmit a legacy beacon at target legacy beacon transmission times (TLBTTs) 1110a, 1110b, 1110c, and 1110d. The TLBTT can equal a sequence number (SN) * a beacon interval, where beacon interval <NUM> can equal <NUM> time units (TUs) (e.g., <NUM>).

Associated STAs receive beacon frames to maintain AP operating parameters and detect availability of buffered DL frames from the beacon frame. Passive scanning is based on the fixed beacon duration. A passively scanning STA selects the duration for the channel and listens to ensure at least one beacon frame transmission is received during the listening interval, e.g., approximately <NUM> scanning time at a channel. Some passive scanning enhancements transmit a frame (unsolicited probe responses) more frequently to make a BSS more easily discoverable and to reduce active scanning. An attacker may use fixed beacon transmission interval to track the AP. Some embodiments provide privacy enhancement by using a random beacon transmission interval to make PE AP tracking more challenging and complex.

<FIG> illustrates example <NUM> of randomization of PE beacon transmission periodicity, according to some embodiments of the disclosure. Some embodiments include determining target PE beacon transmission times (TPBTTs) 1140a-1140d based on beacon intervals (e.g., beacon intervals 1145a-1145d) plus a corresponding random time offset <NUM> for SN X (e.g., corresponding random time offsets 1155a-1155d). Time intervals can be settable and can include a default value (e.g., every <NUM> TUs. ) A size of a PE beacon randomization window (e.g., 1150a-<NUM>150d) can be configured as well and can be set to a default (e.g., <NUM> TUs, or <NUM>% of a beacon transmission interval (e.g., <NUM>% of <NUM> TUs.

In some embodiments, a TPBTT can be determined as follows: <MAT> where RandomTimeOffsetHASH has a value [-<NUM>,+<NUM>].

The salt can be stored by a PE STA. Each associated STA can calculate the Random offset <NUM> and determine the next TPBTT. The actual beacon transmission time may be delayed if the channel is busy during TPBTT. PE AP beacon randomization embodiments do not make changes to TSF.

As shown in example <NUM>, the randomization added to PE beacon transmissions make TPBTTs 1140a-1140d harder for an attacker to track compared to the TLBTTs 1110a-1100d of example <NUM>. Assuming a default PE beacon transmission interval of <NUM> TUs, and a default PE beacon randomization window of <NUM> TUs, passive scanning time <NUM> for receiving a PE beacon in a channel may be: <NUM>+ Max Random time = <NUM>. The listening time may be longer than the beacon interval to have some tolerance for delayed beacon transmissions. For instance, the channel may be busy at TBTT, so the beacon may be transmitted after the channel is idle again. As an example, for a <NUM> band with <NUM> non-overlapping channels, a corresponding passive scanning time for these <NUM> non-overlapping channels can be <NUM> (e.g., <NUM> channels* <NUM>=<NUM>.

<FIG> illustrates example method <NUM> for a PE STA utilizing PE beacon frames, according to some embodiments of the disclosure. For explanation purposes and not a limitation, <FIG> may be described with reference to elements from other figures in the disclosure. For example, method <NUM> may be performed by PE STA <NUM> and/or PE STA <NUM> of <FIG> or system <NUM> of <FIG>.

At <NUM>, PE STA <NUM> can select the received beacon. For instance, if a PE STA has got unicast DL frames, the PE STA may wake up for the next PE beacon to check if there are more DL frames coming. If no DL frames are received, the PE STA may wake up to receive the next group addressed frames, or the PE STA may save power and wake up again only for a PE beacon that is transmitted after a long time. If the PE STA is multilink device, the PE STA may only wake up to receive PE beacons in one of the links of the multiple links.

At <NUM>, PE STA <NUM> can calculate a Target PE Beacon Transmission Time (TPBTT) for the beacon.

At <NUM>, PE STA <NUM> can configure PE beacon parameters (e.g., random ID and checksum ID) to be received.

At <NUM>, PE STA <NUM> can wake before the selected and calculated TPBTT.

At <NUM>, PE STA <NUM> can receive a partial PE beacon frame, at least the MAC header and Change Sequence Number <NUM>.

At <NUM>, PE STA <NUM> determines whether the MAC Header of the PE beacon frame received satisfies the configured beacon parameters (e.g., random ID and checksum ID substantially matches the configured random ID and checksum ID from beacon update elements as listed in Table <NUM>. ) When the received parameters (e.g., elements) match with the configured PE beacon parameters, and the Change Sequence Number of the PE beacon frame matches with the saved Change Sequence Number of the last received PE beacon frame, then the receiver knows that BSS parameters have not changed. Thus, the receiver may not need to receive and parse the remainder of the PE beacon frame field, or the receiver may parse only selected elements like TIM. If the Change Sequence Number does not match with the saved value, then the PE STA receives the complete PE beacon frame (e.g., the remainder of the PE beacon frame.

The received PE beacon frame may not be for the PE STA (e.g., MAC header of the PE beacon frame does not satisfy the configured beacon parameters) and the PE STA may continue to receive and try to receive a PE beacon frame. Method <NUM> returns to <NUM>.

In some examples, the PE STA may stop receiving the PE beacon frame and consider that the PE beacon frame is lost. Method <NUM> then proceeds to <NUM>. In this case, the STA selects the next PE beacon to receive <NUM>. If the received PE beacon frame is for the PE STA, method <NUM> proceeds to <NUM>.

At <NUM>, when the configured PE beacon parameters are not satisfied, PE STA <NUM> returns to a doze state, and method <NUM> returns to <NUM>.

At <NUM>, when the configured PE beacon parameters are satisfied, PE STA <NUM> determines whether there is interest in the buffered DL frames (e.g., based on TIM or if a change sequence number indicates a pending change). When PE STA <NUM> is not interested in the buffered DL frames, method <NUM> returns to <NUM>. Otherwise, method <NUM> proceeds to <NUM>.

At <NUM>, PE STA <NUM> receives the buffered DL frames.

<FIG> illustrates example method <NUM> for a PE AP utilizing PE beacon frames, according to some embodiments of the disclosure. For explanation purposes and not a limitation, <FIG> may be described with reference to elements from other figures in the disclosure. For example, method <NUM> may be performed by AP <NUM>, PE AP <NUM>, and/or PE AP <NUM> of <FIG> or system <NUM> of <FIG>.

At <NUM>, PE AP <NUM> can associate with a privacy enhanced (PE) station (STA).

At <NUM>, PE AP <NUM> can configure a PE beacon frame that includes a random ID and checksum ID corresponding to PE AP <NUM>.

At <NUM>, PE AP <NUM> can transmit the PE beacon frame according to a target PE beacon transmission time (TPBTT).

At <NUM>, PE AP <NUM> can determine whether the PE beacon frame includes multiple PE BSSIDs. When the PE beacon frame (e.g., a PE discovery beacon frame) includes multiple PE BSSIDs, method <NUM> proceeds to <NUM>. Otherwise, method <NUM> proceeds to <NUM>.

At <NUM>, PE AP <NUM> includes an unencrypted PE reduced neighbor report (RNR) in the PE discovery beacon frame where the PE RNR includes a neighbor random ID, neighbor checksum ID, and corresponding PE multiple basic service set ID (MBSSID) size that corresponds to a neighbor PE BSS specific info field that is encrypted. The PE AP repeats the BSS information addition to PE RNR and the PE BSS specific information for each BSS which information is added to the PE discovery beacon frame.

At <NUM>, PE AP <NUM> includes an encrypted change sequence number adjacent to a MAC header field (e.g., the PE AP transmits an encrypted PE beacon frame.

<FIG> illustrates example system <NUM> supporting a legacy beacon frame carrying PE BSS(s) information, in accordance with some embodiments of the disclosure. Example system <NUM> includes legacy STA compatible (LSC) AP <NUM> with a BSS with an SSID (e.g., "Coffee shop"). LSC AP <NUM> can associate with legacy STA <NUM> and PE STA <NUM> and LSC AP <NUM> can access network <NUM>. For explanation purposes and not a limitation, <FIG> may be described with reference to elements from other figures in the disclosure. For example, network <NUM> may be the same as network <NUM> of <FIG>, and PE STA <NUM> may correspond to PE STA <NUM> or PE STA <NUM> of <FIG>. LSC AP <NUM> is not suitable for use cases that require AP privacy, like Mobile AP, or AP in a car. While LSC AP <NUM> privacy cannot be improved, LSC AP <NUM> can include privacy enhancements for PE STA <NUM>.

<FIG> illustrates example <NUM> of a legacy beacon format with PE BSS information, according to some embodiments of the disclosure. For explanation purposes and not a limitation, <FIG> may be described with reference to elements from other figures in the disclosure. For example, PE RNR <NUM> may correspond to PE RNR <NUM> of <FIG> and and RNR <NUM> may correspond to RNR <NUM> of <FIG>, respectively. Example <NUM> includes legacy BSSs information <NUM> and PE RNR <NUM> includes information including sizes for PE BSS Specific Info subelements (e.g., for each PE BSS, a corresponding size of PE BSS specific info <NUM>-<NUM> through <NUM>-M are included).

Various embodiments can be implemented, for example, using one or more well-known computer systems, such as computer system <NUM> shown in <FIG>. Computer system <NUM> can be any well-known computer capable of performing the functions described herein. For example, and without limitation, AP <NUM>, PE AP <NUM>, PE STA <NUM>, PE AP <NUM>, PE STA <NUM> of <FIG>, PE STA <NUM>, LSC AP <NUM> of <FIG>, system <NUM> of <FIG>, method <NUM> of <FIG>, method <NUM> of <FIG>, (and/or other apparatuses and/or components shown in the figures) may be implemented using computer system <NUM>, or portions thereof.

Processor <NUM> is connected to a communication infrastructure <NUM> that can be a bus. One or more processors <NUM> may each be a graphics processing unit (GPU). In an embodiment, a GPU is a processor that is a specialized electronic circuit designed to process mathematically intensive applications. The GPU may have a parallel structure that is efficient for parallel processing of large blocks of data, such as mathematically intensive data common to computer graphics applications, images, videos, etc..

Computer system <NUM> also includes a main or primary memory <NUM>, such as random access memory (RAM). Main memory <NUM> may include one or more levels of cache. Main memory <NUM> has stored therein control logic (e.g., computer software) and/or data.

According to some embodiments, secondary memory <NUM> may include other means, instrumentalities or other approaches for allowing computer programs and/or other instructions and/or data to be accessed by computer system <NUM>. Such means, instrumentalities or other approaches may include, for example, a removable storage unit <NUM> and an interface <NUM>. Examples of the removable storage unit <NUM> and the interface <NUM> may include a program cartridge and cartridge interface (such as that found in video game devices), a removable memory chip (such as an EPROM or PROM) and associated socket, a memory stick and USB port, a memory card and associated memory card slot, and/or any other removable storage unit and associated interface.

The operations in the preceding embodiments can be implemented in a wide variety of configurations and architectures. Therefore, some or all of the operations in the preceding embodiments may be performed in hardware, in software or both. In some embodiments, a tangible, non-transitory apparatus or article of manufacture includes a tangible, non-transitory computer useable or readable medium having control logic (software) stored thereon is also referred to herein as a computer program product or program storage device. This includes, but is not limited to, computer system <NUM>, main memory <NUM>, secondary memory <NUM> and removable storage units <NUM> and <NUM>, as well as tangible articles of manufacture embodying any combination of the foregoing. Such control logic, when executed by one or more data processing devices (such as computer system <NUM>), causes such data processing devices to operate as described herein.

Based on the teachings contained in this disclosure, it will be apparent to persons skilled in the relevant art(s) how to make and use embodiments of the disclosure using data processing devices, computer systems and/or computer architectures other than that shown in <FIG>. In particular, embodiments may operate with software, hardware, and/or operating system implementations other than those described herein.

The Summary and Abstract sections may set forth one or more but not all exemplary embodiments of the disclosure as contemplated by the inventor(s), and thus, are not intended to limit the disclosure or the appended claims in any way.

In addition, alternative embodiments may perform functional blocks, steps, operations, methods, etc. using orderings different from those described herein.

References herein to "one embodiment," "an embodiment," "an example embodiment," or similar phrases, indicate that the embodiment described may include a particular feature, structure, or characteristic, but every embodiment may not necessarily include the particular feature, structure, or characteristic.

The breadth and scope of the disclosure should not be limited by any of the above-described exemplary embodiments, but should be defined only in accordance with the appended claims.

Claim 1:
A privacy enhanced, PE, station, STA, comprising:
a transceiver (<NUM>); and
a processor (<NUM>) communicatively coupled to the transceiver, configured to:
receive (<NUM>), via the transceiver, a PE beacon frame (<NUM>) comprising a media access control, MAC, header that includes a first random identifier, ID, (<NUM>,<NUM>) and a first checksum ID (<NUM>, <NUM>), wherein the IDs correspond to an affiliated PE access point, AP, of a PE AP multilink device, MLD; and the processor is further configured to:
select an AP MLD ID of the PE AP MLD;
determine a checksum value using the AP MLD ID and the first random ID;
determine whether the first checksum ID satisfies the checksum value; and
process, responsive to the determining, the PE beacon frame.