Patent Publication Number: US-2023139206-A1

Title: Methods and arrangements for transition between access points of a non-collocated multi-link device

Description:
TECHNICAL FIELD 
     This disclosure generally relates to methods and arrangements for wireless communications and, more particularly, to transition of a non-access point (non-AP) multi-link device (MLD) between access point stations (STAs) of a non-collocated MLD. 
     BACKGROUND 
     The increase in interest in network and Internet connectivity drives design and production of new wireless products. The escalating numbers of wireless devices active as well as the bandwidth demands of the users of such devices are increasing bandwidth demands for access to wireless channels. 
     In addition to the demands to increase bandwidth and data throughput from users, the proliferation of mobile wireless devices with high bandwidth and data throughput capabilities has also increased demands for smooth mobility. The Institute of Electrical and Electronics Engineers (IEEE) is developing one or more new standards that utilize Orthogonal Frequency-Division Multiple Access (OFDMA) in channel allocation to increase bandwidth and data throughput capabilities of the devices such as access point stations and non-access point stations, to increase bandwidth and data throughput to meet demands from users. These new standards may require operability with legacy devices and other concurrently developing communications standards. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1 A  depicts a system diagram illustrating an embodiment of a network environment for transition logic circuitry, in accordance with one or more example embodiments. 
         FIG.  1 B  depicts an embodiment illustrating interactions between stations (STAs) of a collated access point (AP) multi-link device (MLD) and a non-collocated AP MLD. 
         FIG.  1 C  depicts an embodiment of a system including multiple MLDs. 
         FIG.  1 D  illustrates an embodiment of a radio architecture for STAs, such as the wireless interfaces for STAs depicted in  FIGS.  1 A-C , to implement transition logic circuitry. 
         FIG.  1 E  illustrates an embodiment of front-end module (FEM) circuitry of a wireless interface for STAs, such as the STAs in  FIGS.  1 A-C , to implement transition logic circuitry. 
         FIG.  1 F  illustrates an embodiment of radio integrated circuit (IC) circuitry of a wireless interface for STAs, such as the STAs in  FIGS.  1 A-C , to implement transition logic circuitry. 
         FIG.  1 G  illustrates an embodiment of baseband processing circuitry of a wireless interface for STAs, such as the STAs in  FIGS.  1 A-C , to implement transition logic circuitry. 
         FIG.  2 A  depicts an embodiment of transmissions between four stations and an AP. 
         FIG.  2 B  depicts an embodiment of a transmission between one station and an AP. 
         FIG.  2 C  depicts an embodiment of a resource units. 
         FIG.  2 D  depicts an embodiment of a multiple user (MU) physical layer (PHY) protocol data unit (PPDU). 
         FIG.  2 E  depicts another embodiment of a MU PPDU comprising a data field for a MAC management frame such as the management frame shown in  FIG.  2 F . 
         FIG.  2 F  depicts an embodiment of a physical layer service data unit (PDSU) comprising a MAC management frame such as shown in  FIGS.  2 G-I . 
         FIG.  2 G  depicts an embodiment of frame body elements for an association request frame or a reassociation request frame such as the management frame shown in  FIG.  2 F . 
         FIG.  2 H  depicts an embodiment of frame body elements for an association response frame or reassociation response frame such as the management frame shown in  FIG.  2 F . 
         FIG.  2 I  depicts an embodiment of a frame body of a TID-to-Link mapping request/response frame such as the management frame shown in  FIG.  2 F . 
         FIG.  2 J  depicts an embodiment of a multi-link (ML) element of a MAC management frame such as the management frames shown in  FIGS.  2 F- 2 I . 
         FIG.  2 K  depicts an embodiment of a common info field of a ML element such as the ML elements shown in  FIGS.  2 G- 2 J . 
         FIG.  2 L  depicts an embodiment of a link ID info field of a common info field of a ML element such as the common info field in  FIG.  2 K  and the ML elements shown in  FIGS.  2 G- 2 J . 
         FIG.  2 M  depicts an embodiment of a link info field of a ML element such as the ML elements shown in  FIGS.  2 G- 2 J . 
         FIG.  2 N  depicts an embodiment of a mapping table to track new link values created by the transition logic circuitry of an AP MLD to represent links between a non-AP MLD STA and an AP STA of another AP MLD. 
         FIG.  2 O  depicts an embodiment of a TID-to-Link mapping element of a TID-to-Link mapping request/response frame such as the TID-to-Link mapping request/response frame shown in  FIG.  2 I . 
         FIG.  2 P  depicts an embodiment of a TID-to-Link control field of a TID-to-Link mapping element such as the TID-to-Link mapping element shown in  FIG.  2 O . 
         FIG.  2 Q  depicts another embodiment of a physical layer (PHY) frame comprising a data field (or payload) for a MAC management frame such as the frame shown in  FIG.  2 F . 
         FIG.  2 R  depicts the MAC management frame such as the frame shown in  FIG.  2 F . 
         FIG.  3    depicts an embodiment of a wireless communications interface with transition logic circuitry such as the wireless communications interface shown in  FIG.  1 C . 
         FIG.  4 A  depicts an embodiment of a flowchart to implement transition logic circuitry such as the transition logic circuitry discussed in conjunction with  FIGS.  1 - 3   . 
         FIG.  4 B  depicts another embodiment of a flowchart to implement transition logic circuitry such as the transition logic circuitry discussed in conjunction with  FIGS.  1 - 3   . 
         FIGS.  4 C-D  depict embodiments of flowcharts to generate and transmit frames and receive and interpret frames for communications between wireless communication devices. 
         FIG.  5    depicts an embodiment of a functional diagram of a wireless communication device, in accordance with one or more example embodiments of the present disclosure. 
         FIG.  6    depicts an embodiment of a block diagram of a machine upon which any of one or more techniques may be performed, in accordance with one or more embodiments. 
         FIGS.  7 - 8    depict embodiments of a computer-readable storage medium and a computing platform to implement transition logic circuitry. 
     
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
     The following description and the drawings sufficiently illustrate specific embodiments to enable those skilled in the art to practice them. Other embodiments may incorporate structural, logical, electrical, process, algorithm, and other changes. Portions and features of some embodiments may be included in, or substituted for, those of other embodiments. Embodiments set forth in the claims encompass all available equivalents of those claims. 
     One of the objectives for Wi-Fi 8 is to allow smooth mobility with zero or low latency and with zero or low packet losses during transitions between access points (APs) in different locations by multi-link (ML) devices (MLDs). The MLDs defined in Institute of Electrical and Electronic Engineers (IEEE) 802.1 1be D2.2, draft standard October 2022, define protocols for collocated access point (AP) MLDs. To meet the objectives for smooth mobility, embodiments described herein may define novel protocols and operations for transitioning for a non-collocated AP MLD for Wi-Fi 8, Wi-Fi 9, and/or other wireless communications standards. 
     Embodiments may comprise transition logic circuitry to associate links of more than one STAs of MLDs. Links may be established (or logical) communications channels or connections between MLDs. MLDs include more than one stations (STAs). For instance, an AP MLD and a non-AP MLD may both include STAs configured for multiple frequency bands such as a first STA configured for 2.4 gigahertz (GHz) communications, a second STA configured for 5 GHz communications, and a third STA configured for 6 GHz communications. 
     In many embodiments discussed herein, MLDs have STAs operating on the same set of carrier frequencies but MLDs are not limited to STAs with any particular set of carrier frequencies. For example, embodiments may comprise MLDs that have a set of STAs operating on one or more overlapping carrier frequencies such as STAs with carrier frequencies in a range of sub 1 GHz, 1 GHz to 7.25 GHz, 7.25 GHz to 45 GHz, above 45 GHz, around 60 GHz, and/or the like. 
     Note that STAs may be AP STAs or non-AP STAs and may each be associated with a specific link of an MLD. Note also that an MLD can include AP functionality in one or more STAs for one or more links and, if a STA of the MLD operates as an AP on a link, the STA is referred to as an AP STA. If the STA does not perform AP functionality, or does not operate as an AP, on a link, the STA is referred to as a non-AP STA. In many of the embodiments herein, the AP MLDs operate as AP STAs on active links, and the non-AP MLDs operate as non-AP STAs on active links. However, an AP MLD may also have STAs that operate as non-AP STAs on the same extended service set (ESS) or basic service set (BSS) or other ESS’s or BSS’s. 
     The concept for a non-collocated MLD is to define operations for an MLD that can have multiple non-collocated, affiliated AP STAs. In many embodiments discussed herein, the non-collocated MLD is organized as non-collocated groups of collocated STAs, wherein each group of STAs is collocated and referred to as a collocated MLD. In many embodiments, each group of collocated STAs may reside in a single housing but embodiments are not limited to collocated STAs being within a single housing. In some embodiments, all AP STAs in an extended service set (ESS) may be affiliated to (or associated with) the same non-collocated AP MLD. The same AP STAs may also be associated with respective collocated AP MLDs. 
     In an infrastructure BSS, the IEEE 802.1X Authenticator MAC address (AA) and the AP STA’s MAC address are the same, and the Supplicant’s MAC address (SPA) and the non-AP STA’s MAC address are the same. Between an AP MLD and a non-AP MLD, in many embodiments, the IEEE 802.1X Authenticator MAC address (AA) may be set to the MLD MAC address of the AP MLD, and the Supplicant’s MAC address (SPA) may be set to the MLD MAC address of the non-AP MLD, but embodiments are not limited to such MAC address assignments. Note that the MAC address for a MLD (AP or non-AP) may be the same as a MAC address of one of the STAs of the MLD or may be different from the MAC addresses of all the STAs of the MLD. For instance, if the MLD has three STAs, the MAC address of the MLD may be the same MAC address as, e.g., the first STA of the MLD in some embodiments. In other embodiments, the MAC address of the MLD may be different from all three of the MAC addresses of the STAs of the MLD. 
     In some embodiments, the MAC address is encoded as 6 octets, taken to represent an unsigned integer. The first octet of the MAC address may be used as the most significant octet. The bit numbering conventions may be used within each octet. In such embodiments, this results in a sequence of 48 bits represented such that bit 0 is the first transmitted bit (Individual/Group bit) and bit 47 is the last transmitted bit. Note that the value of the MAC address included in a field of a MAC frame may comprise the complete MAC address, a compressed or encoded MAC address, a truncated MAC address such as a set of the least significant bits of the MAC address or the last four bits of a MAC address, and/or the like. 
     Some embodiments may use the same security keys for, e.g., authentication and/or data security, on all APs affiliated to the same non-collocated AP MLD, even if the APs are not collocated. Some embodiments may implement different security keys for, e.g., authentication and/or data security, such that the same security keys are used within a group of collocated AP STAs of a non-collocated AP MLD and different security keys are used between different groups of collocated AP STAs of the non-collocated AP MLD. 
     Many embodiments describe methods and arrangements for transition between access point STAs of a non-collocated AP MLD. Some embodiments define a non-collocated MLD, in the presence of IEEE 802.11be stations (STAs) that do not support non-collocated MLD operation. Therefore, every set of collocated APs will then have a dedicated AP MLD. Each set of collocated AP MLDs, such as a first AP MLD or a second AP MLD, may be identified by, e.g., a single MAC address such as the AA. This is extendable to many more AP MLDs. 
     Under an IEEE 802.11be standard protocol, the non-AP MLDs may transition between the first AP MLD (AP MLD 1) and the second AP MLD (AP MLD 2) with, e.g., a fast transition (FT) protocol. Furthermore, under the same IEEE 802.11be standard protocol, the non-AP MLDs may not understand if the two AP MLDs have the same AP MLD MAC address to identify an affiliated non-collocated AP MLD. Embodiments herein may define a protocol to advantageously reduce latency and packet loss during transitions from a link with an AP STA of a first collocated AP MLD, AP MLD 1, to a link with an AP STA of a second collocated AP MLD (AP MLD 2), wherein both the first collocated AP MLD and the second collocated AP MLD are affiliated with a non-collocated AP MLD. 
     To deploy a non-collocated AP MLD (AP MLD 3), embodiments may define a new non-collocated AP MLD (AP MLD 3) that overlaps with the existing collocated AP MLD 1 and AP MLD 2. In such embodiments, the non-AP MLDs that are capable of supporting non-collocated MLD operation may associate with the AP MLD 3 and transition between links of the AP MLD 1 and AP MLD 2. Furthermore, the non-AP MLDs that do not support non-collocated MLD operation, such as IEEE 802.11be MLDs, may associate separately with AP MLD 1 and/or AP MLD 2. 
     In many embodiments, an AP STA may be affiliated with both a collocated AP MLD and a non-collocated AP MLD. 
     Embodiments may comprise transition logic circuitry to perform transitions of links of a non-AP MLD that has performed a non-collocated MLD association with a non-collocated AP MLD. For example, a non-AP MLD may perform multi-link (ML) association with the non-collocated AP MLD 3 and establish ML setup with the links of AP STA 1, AP STA 2, and AP STA 3 of the collocated AP MLD 1. As the non-AP MLD moves away from AP STA 1, AP STA 2, and AP STA 3 of the collocated AP MLD 1 and towards AP STA 4, AP STA 5, and AP STA 6 of the collocated AP MLD 2; the non-AP MLD may transition links to AP STA 4, AP STA 5, and AP STA 6 of the collocated AP MLD 2. In some embodiments, the non-AP MLD may transition from AP STA 1, AP STA 2, and AP STA 3 and to AP STA 4, AP STA 5, and AP STA 6 one at a time as the individual link signal strengths associated with the links to AP STA 4, AP STA 5, and AP STA 6 become stronger or may transition from AP STA 1, AP STA 2, and AP STA 3 and to AP STA 4, AP STA 5, and AP STA 6 all at the same time. Note that even if all these APs are part of the same AP MLD, they may not be part of the ML association. 
     In some embodiments, a non-AP MLD may be associated with different AP STAs from multiple collocated AP MLDs that are part of the same non-collocated AP MLD. For instance, a location of a non-AP MLD may be nearest to a first AP MLD but also within range of a second AP MLD that is affiliated with the same non-collocated AP MLD as the first AP MLD. The non-AP MLD may receive the strongest signal from a 2.4 GHz AP STA for a 2.4 GHz link of the first AP MLD but, due to an obstruction, signal interference, or other interference with receipt of transmissions from a 6 GHz AP STA of the first AP MLD, the non-AP MLD may receive the strongest signal from a 6 GHz AP STA via a 6 GHz link of the second AP MLD. In some embodiments, such circumstances may cause the non-AP STA to associate with the 2.4 GHz AP STA of the first AP MLD and the 6 GHz AP STA of the second AP MLD. 
     The transitioning of non-AP STAs of an MLD from AP STAs of a first AP MLD to a second AP MLD of a non-collocated AP MLD may involve a process including an optional pre-transition phase, a new link phase, a link enablement/disablement phase, and a link removal phase. 
     The option pre-transition phase may prepare one or more AP MLDs for the transition from a first AP MLD of (affiliated with) a non-collocated AP MLD to a second AP MLD of the non-collocated AP MLD. The pre-transition phase may account for the latency and difficulty involved with sharing buffers and scoreboards across non-collocated AP MLDs. During the pre-transition phase, the non-AP MLD may indicate, to the first AP MLD, a pending transition to the second AP MLD (or possibly more than one second AP MLD). The indication may trigger sharing of buffers and scoreboards in the first AP MLD with the second AP MLD(s) and duplication of frames if needed across AP MLDs to prepare for the transition. At the time of the transition, at a predetermined time period prior to the transition, or at a predetermined event prior to the transition; the non-AP MLD may send the status of the non-AP MLD’s Block Acknowledgement (BA) for downlink (DL) data from the first AP MLD to the second AP MLD and possibly the buffer status for uplink (UL) data to the second AP MLD. For instance, after receiving DL data from the first AP MLD, the non-AP MLD may transmit the BA to the first AP MLD, the second AP MLD, or both the first AP MLD and the second AP MLD, to acknowledge receipt of the DL data from the buffer of the first AP MLD. 
     During the new link phase, new links may be associated with the non-AP MLD. With reference to  FIG.  2   , the current association includes links AP1, AP2, and AP3 of AP MLD 1 and the transition may be to the links AP4, AP5, and AP6 of the AP MLD 2. Thus, during the new link phase in this example, the to the non-AP MLD may associate with AP STA 4, AP STA 5, and AP STA 6 to establish links AP4, AP5, and AP6 with the AP MLD 2 of the non-collocated AP MLD 3. 
     The association process may allow the non-AP MLD to add a new link to its MLD association with an AP MLD (associate a new STA in the non-AP MLD to a new AP in the associated AP MLD) without changing association status for other STAs/APs in the MLDs. For instance, the non-AP MLD may associate links AP4, AP5, and AP6 with the AP MLD 2 without changing the association status of the links AP1, AP2, and AP3 with the AP MLD 1. 
     In some embodiments, the non-AP MLD may transmit a Reassociation Request frame and receive a Reassociation Response frame that includes a new flag indicating that it is a (re)association with a Link add, which means that previous associations will not be tore down, but only new links are added. 
     In some embodiments, the Reassociation Request frame and receive a Reassociation Response frame may identify the recipient as the non-collocated AP MLD. In such embodiments, the Reassociation Request frame and receive a Reassociation Response frame may include a recipient address field with an MLD MAC address of the non-collocated AP MLD, a recipient address field with an MLD ID of the non-collocated AP MLD, and/or a flag field with one or more bits to indicate that the frame is addressed for the non-collocated AP MLD in a header of the Reassociation Request frame and a Reassociation Response frame or in a common info field of the ML element (or basic ML element) included in the frame body of the Reassociation Request frame and a Reassociation Response frame. 
     In some embodiments, the Reassociation Request frame and receive a Reassociation Response frame may identify the new link in a per-STA profile. The per-STA profile may include every new link that is requested to be added. The per-STA profile may comprise a per-STA profile subelement may be in a link info field of a basic multi-link element that may be included in the frame body of the Reassociation Request frame and a Reassociation Response frame. 
     In some embodiments, a new field in the Per-STA profile may include a combination of the link ID field and the MLD ID field (depending to which AP this is sent) or combination of the link ID field and the MLD MAC address (of the collocated AP MLD). Thus, the new field may provide the MLD MAC address of the collocated AP MLD and/or the MLD ID so that this field in combination with the link ID uniquely identifies the link. 
     In some embodiments, the non-AP MLD may send a Reassociation Request frame and receive a Reassociation Response frame may, for association of every new link, include the complete information of the corresponding STA for every new link in the per-STA profile of the ML element. Additionally, some embodiments may allow for flexibility by the AP MLD or a control AP STA of the collocated/non-collocated groups to prohibit a request from a non-AP MLD. This allows control of a network if needed, to enable potentially enhanced security. 
     In the reassociation response frame, the AP MLD may assign a new link ID to the AP STA of the AP MLD of the non-collocated AP MLD. Legacy MLDs may identify an AP STA by the collocated AP MLD with which it is affiliated, and the link ID associated with the AP STA within the collocated AP MLD. By assigning a new link ID specifically for a non-collocated AP MLD, some embodiments may reuse some of or all the mechanisms (TID-to-link mapping, enhanced multi-link single radio (EMLSR) operation link enablement, etc.) that use a link bitmap or link ID field and that are bounded to 15 links (while the non-collocated AP MLD may know more than 15 links). The Link ID for the non-collocated AP MLD may then be valid only for the associated non-AP MLD and may be different for another non-AP MLD. 
     In many embodiments, the non-collocated AP MLD link ID may be used for every frame that is unicasted between the non-AP MLD and the non-collocated AP MLD (TID-to-link mapping frames, eMLSR link enablement, etc.). In some embodiments, an AP STA of (affiliated with) a collocated AP MLD and the non-collocated AP MLD may use the link ID of the collocated AP MLD for frames that are sent to the groupcast address (and/or broadcast address) by the AP STA. 
     Such embodiments may implement a mapping with, e.g., a mapping table maintained at a collocated AP MLD of the non-collocated AP MLD. Further embodiments may setup each link, via association and/or reassociation frames, between the non-AP MLD and the non-collocated AP MLD using the link ID of the non-collocated AP MLD and a link ID combined with the MLD ID, or MLD MAC address of the collocated AP MLD. 
     In some embodiments, the mapping table may be defined with the collocated AP MLD field and a non-collocated AP MLD field. The collocated AP MLD field may contain the link ID field with the linkID of the collocated AP MLD and the MLD MAC address or MLD ID field of the collocated AP MLD in addition to the non-collocated AP MLD field containing the link ID field with the linkID of the non-collocated AP MLD. 
     In some embodiments, a new field called non-collocated link ID field is included in the Per-STA profile of the ML element in an association response or a reassociation response. The per-STA profile may have, such as the new fields in the association/reassoication response, a link ID field, and a collocated AP MLD MAC Address field to uniquely identify an AP STA of a collocated AP MLD of a non-collocated AP MLD. 
     In further embodiments, a new frame is defined for the purpose of adding new links to an association of a non-AP MLD instead of, or in addition to, using the association request/response frame. The new frame has the advantage of providing protection for the frame. In some embodiments, the format of the new frame may be the same frame format as the Association request/response frame but may be protected. A protected frame may include data protected via a cryptographic encapsulation process. The protected frame may be decapsulated at the receiver by a decapsulation process may generating plaintext data from a cryptographic payload of an unprotected frame. 
     After the link add phase, the non-AP MLD may be associated to the non-collocated AP MLD via links AP STA 1, AP STA 2, and AP STA 3 and links AP STA 4, AP STA 5, and AP STA 6. Thereafter, the link enablement/disablement phase may enable the new links and disable the old links using TID-link-mapping function. 
     During the link enablement/disablement phase, the non-AP MLD may transmit a TID-to-link mapping request frame and receive a TID-to-link mapping response frame including the link ID of the non-collocated AP MLD to enable the links or disable the links. 
     In some embodiments, such as embodiments for which it is not already clear based on the MAC address of the receiver address (RA) / transmitter address (TA), for explicit indication that the frames are for non-collocated AP MLD, a flag field may be included in the TID-to-link mapping frame comprising one or more bits to clarify that the frame exchange is for the non-collocated AP MLD and that the link IDs identified in the frame are the link IDs of the non-collocated AP MLD. 
     At some point, all links may be enabled. In some embodiments, for instance, all the new links may be enabled, and the old links may remain enabled. In some embodiments, all the new links are enabled in the same frame exchange between the non-AP MLD and the non-collocated AP MLD. In some embodiments, the new links may be enabled in one or more different frame exchanges between the non-AP MLD and the non-collocated AP MLD. In some embodiments, in one frame exchange, some links may be enabled, and some links may be disabled. In some embodiments, in one frame exchange, all new links may be enabled, and all old links may be disabled. In some embodiments, all the old links are disabled in the same frame exchange between the non-AP MLD and the non-collocated AP MLD. In some embodiments, the old links may be disabled in one or more different frame exchanges between the non-AP MLD and the non-collocated AP MLD. 
     After the enablement/disablement phase, the new links (e.g., AP STA 4, AP STA 5, and AP STA 6) may be enabled and the old links (e.g., AP STA 1, AP STA 2, and AP STA 3) may be disabled. During the link removal phase, old links may be fully removed from MLD association. 
     Many embodiments may define new link delete functionality or link removal functionality to tear down the association of only some links within a ML association, without tearing down the ML association and without touching to the association of the links that remain in the ML association. In some embodiments, a new frame is defined to perform the link delete action. Some embodiments may modify the association request/response frame to include the link delete functionality in addition to the link add functionality. In some embodiments, a Disassociation frame format is modified to enable the link delete functionality. 
     In such embodiments, the links that are torn down are identified by the link ID of the non-collocated AP MLD, for instance in a multi-link element, using the link ID fields in per-STA profile. The per-STA profile in this ML element may be empty if only the link ID is needed. 
     Once links are removed, in some embodiments, the AP MLD may re-set the link IDs for the non-AP MLD. In such embodiments, the AP MLD may perform a link ID change frame exchange initiated by the AP MLD by sending a frame to the to the non-AP MLD, that may indicate one link or a list of links. For each link, the frame may provide the old link ID and the new link ID. 
     In some embodiments, the process of re-setting the link IDs for the non-AP MLD by the AP MLD may be performed along with a disassociation procedure if there is a response from the AP MLD and the disassociation procedure was initiated by the non-AP MLD side. In some embodiments, the process of re-setting the link IDs for the non-AP MLD by the AP MLD may be performed along with a disassociation procedure if the process is initiated by the AP MLD. Re-setting the link IDs for the non-AP MLD may be performed by including the information for each link that is changed of the old link ID and the new link ID. 
     In some embodiments, a query can be sent by either link to do a discovery of the current mapping table (or association table) that was established in the new link phase. Such embodiments may allow any link to confirm the current status of the mapping table in case link messages were missed. 
     Embodiments may comprise transition logic circuitry to transition links such as a 2.4 GHz link, a 5 GHz link, or a 6 GHz link, of a non-AP MLD between one or more collocated AP MLDs of a non-collocated AP MLD. Note that while many examples of embodiments discussed herein discuss 2.4 GHz link, a 5 GHz link, or a 6 GHz links, links with have any carrier frequency. Some embodiments may advantageously use of 2.4 GHz links, 5 GHz links, or 6 GHz links due to the proliferation of 2.4 GHz link and 5 GHz link devices as well as the current utility and efficiencies related to the implementation of 6 GHz links. Embodiments discussed herein will be advantageous from an operational and efficiency standpoint regardless of the carrier frequencies. 
     In some embodiments, the AP MLD may include a 6 GHz AP STA that is also a channel enabler for the 6 GHz channel. In such embodiments, the channel enabler may connect via, e.g., the Internet to an automated frequency coordination (AFC) system and operate under the control of the AFC system to prevent harmful interference to microwave links that operate in the band. The AFC system may determine on which frequencies and at what power levels standard-power devices may operate and may, in some embodiments, be aware of the location of the AP MLD. For instance, in some embodiments, standard power devices may be able to operate on 5.925-6.425 GHz and 6.525-6.875 GHz portions of the 6 GHz channel. 
     Note that a channel enabler may operate on other frequencies such as 2.4 GHz or 5 GHz to offer more control to a network operator even though such frequencies may not require connection to an AFC system or the like. 
     For maintaining a quality of service (QoS), many embodiments define two or more access categories. Access categories may be associated with traffic to define priorities (in the form of parameter sets) for access to a channel for transmissions (or communications traffic) such as managed link transmissions. Many embodiments implement an enhanced distributed channel access (EDCA) protocol to establish the priorities. In some embodiments, the EDCA protocol includes access categories such as best efforts (AC_BE), background (AC_BK), video (AC_VI), and voice (AC_VO). Protocols for various standards provide default values for parameter sets for each of the access categories and the values may vary depending upon the type of a STA, the operational role of the STA, and/or the like. 
     Embodiments may also comprise transition logic circuitry to facilitate communications by stations (STAs) in accordance with different versions of Institute of Electrical and Electronics Engineers (IEEE) 802.11 standards for wireless communications (generally referred to as “Wi-Fi”) such as IEEE 802.11-2020, December 2020; IEEE P802.11be™/D2.2, October 2022; IEEEP802. 1 1ax-2021™, IEEE P802.1 1ay-2021™, IEEE P802. 11az™/D3.0, IEEE P802.11ba-2021™,IEEE P802.11bb™/D0.4, IEEE P802.11bc™/D1.02, and IEEE P802. 11bd™/D1.1. 
     The above descriptions are for purposes of illustration and are not meant to be limiting. Numerous other examples, configurations, processes, algorithms, etc., may exist, some of which are described in greater detail below. Example embodiments will now be described with reference to the accompanying figures. 
     Various embodiments may be designed to address different technical problems associated with transition of links of a non-AP MLD between AP MLD STAs affiliated with a non-collocated AP MLD; defining a non-collocated AP MLD; updating buffer statuses and scoreboards for a transition between links of collocated AP MLDs; identifying the non-collocated AP MLD as a recipient; identifying the links to transition; adding links while maintaining current links; managing link IDs of new links for a different AP MLD; enabling TID-to-Link mapping for another AP MLD affiliated with the non-collocated AP MLD; enabling added links; disabling old links; removing old links; re-setting link IDs of a non-AP MLD after transitioning from old links with a first AP MLD to new links with a second AP MLD; setup of links for non-collocated AP MLDs; addressing an association request frame, an association response frame, and an TID-to-Link mapping request frame to a non-collocated AP MLD; mapping links for a non-collocated AP MLD; and/or the like. 
     Different technical problems such as those discussed above may be addressed by one or more different embodiments. Embodiments may address one or more of these problems associated with association of a non-AP MLD with a non-collocated AP MLD. For instance, some embodiments that address problems associated with association may do so by one or more different technical means, such as, parsing a first medium access control (MAC) request frame to add new links between a non-AP MLD and a second AP MLD affiliated with the non-collocated AP MLD, the MAC request frame to comprise an address field, wherein the address field comprises a receiver address (RA) that identifies the first AP MLD; a recipient field comprising a value to identify the non-collocated AP MLD; adding a link add field to a MAC request frame to request addition of one or more new links and to maintain current links associated with STAs of the non-AP MLD unchanged; determining that the MAC request frame is addressed to the non-collocated AP MLD or the first AP MLD; generating a MAC response frame comprising an address field comprising the MAC address to identify the non-collocated AP MLD; a MLD ID field comprising the value to identify the non-collocated AP MLD; a non-collocation ID field comprising the value of the flag to indicate whether the MAC frame is addressed from the non-collocated AP MLD or is addressed from the first AP MLD; or a combination thereof; causing transmission of the MAC response frame to the non-AP MLD; using, for authentication, the same security keys for different groups of collocated AP STAs of a non-collocated AP MLD, wherein the different groups of collocated AP STAs are non-collocated; using, for authentication, different security keys for different groups of collocated AP STAs of a non-collocated AP MLD, wherein the different groups of collocated AP STAs are non-collocated; determining a value of a recipient MLD MAC address field for the non-collocated AP MLD ID, wherein the value of the recipient MLD MAC address field comprises an authenticator address; determining the value of the flag, wherein the value of the flag comprises one or more bits, the value to indicate whether the MAC frame is addressed to the non-collocated AP MLD or addressed to the first AP MLD, wherein the first AP MLD is a collocated AP MLD; determining a value for a flag to identify a MAC frame to add new links and maintain current links; generate a medium access control (MAC) request frame, the MAC request frame to comprise a recipient MLD MAC address field comprising a MAC address to identify the non-collocated AP MLD, a recipient identifier (ID) field comprising a value to identify the non-collocated AP MLD, a non-collocation ID field comprising a value of a flag to indicate whether the MAC frame is addressed to the non-collocated AP MLD or is addressed to the first AP MLD, or a combination thereof; causing transmission of the MAC request frame to the non-AP MLD; receiving a MAC response frame to confirm or reject the addition of new links between a non-AP MLD and a second AP MLD affiliated with the non-collated AP MLD; generating a MAC frame to remove old links; determining field values for a MAC frame to remove old links; creating a mapping table with entries for new link IDs between a non-AP STA and another AP MLD; and/or the like. 
     Several embodiments comprise central servers, access points (APs), and/or stations (STAs) such as modems, routers, switches, servers, workstations, netbooks, mobile devices (Laptop, Smart Phone, Tablet, and the like), sensors, meters, controls, instruments, monitors, home or office appliances, Internet of Things (IoT) gear (watches, glasses, headphones, and the like), and the like. Some embodiments may provide, e.g., indoor and/or outdoor “smart” grid and sensor services. In various embodiments, these devices relate to specific applications such as healthcare, home, commercial office and retail, security, and industrial automation and monitoring applications, as well as vehicle applications (automobiles, self-driving vehicles, airplanes, and the like), and the like. 
     Some embodiments may facilitate wireless communications in accordance with multiple standards. Some embodiments may comprise low power wireless communications like Bluetooth®, cellular communications, and messaging systems. Furthermore, some wireless embodiments may incorporate a single antenna while other embodiments may employ multiple antennas or antenna elements. 
     While some of the specific embodiments described below will reference the embodiments with specific configurations, those of skill in the art will realize that embodiments of the present disclosure may advantageously be implemented with other configurations with similar issues or problems. 
       FIG.  1 A  depicts a system diagram illustrating an embodiment of a network environment for transition logic circuitry, in accordance with one or more example embodiments. Wireless network  1000  may include one or more access point (AP) multi-link devices (AP-MLDs)  1005  and  1027 , and one or more user devices  1020  (non-AP MLDs), which may communicate in accordance with IEEE 802.11 communication standards. 
     In the present embodiment, the AP MLD  1005  may comprise a collocated set of AP stations (STAs) and the AP MLD  1027  may comprise a collocated set of AP STAs. Furthermore, the AP MLD  1005  and AP MLD  1027  may be affiliated with the same basic service set (BSS) and may be affiliated with a non-collocated AP MLD  1004 . The non-collocated AP MLD  1004  may comprise a logical non-collocated AP MLD supported by transition logic circuitry in the non-AP MLDs and the AP MLDs to allow STAs such as the user device(s)  1020  to transition links with the AP STAs of the AP MLD  1005  to AP STAs of the AP MLD  1027  via one collocated AP MLD to quickly transition between the AP MLD  1005  and AP MLD  1027  based on, e.g., signal strengths of the corresponding AP STAs, as the user device(s)  1020  move about the network environment or as conditions of the environment change. 
     The user device(s)  1020  may comprise mobile devices that are non-stationary (e.g., not having fixed locations) and/or stationary devices. In some embodiments, the user device(s)  1020  and the AP-MLDs  1005  and  1027  may include one or more computer systems similar to the STAs shown in  FIGS.  1 B- 1 G  and/or the example machine/system of  FIGS.  5 ,  6 ,  7 , and  8   . 
     One or more illustrative user device(s)  1020  and/or AP-MLDs  1005  and  1027  may be operable by one or more user(s)  1010 . It should be noted that any addressable unit may be a station (STA). A STA may take on multiple distinct characteristics, each of which shape its function. For example, a single addressable unit might simultaneously be a portable STA, a quality-of-service (QoS) STA, a dependent STA, and a hidden STA. The one or more illustrative user device(s)  1020  and the AP-MLDs  1005  and  1027  may include STAs. The one or more illustrative user device(s)  1020  and/or AP-MLDs  1005  and  1027  may operate as an extended service set (ESS), a basic service set (BSS), a personal basic service set (PBSS), or a control point/access point (PCP/AP). 
     The user device(s)  1020  (e.g.,  1024 ,  1025 ,  1026 ,  1028 , or  1029 ) and/or AP-MLDs  1005  and  1027  may include any suitable processor-driven device including, but not limited to, a mobile device or a non-mobile, e.g., a static device. For example, user device(s)  1020  and/or AP-MLDs  1005  and  1027  may include, a user equipment (UE), a station (STA), an access point (AP), a software enabled AP (SoftAP), a personal computer (PC), a wearable wireless device (e.g., bracelet, watch, glasses, ring, etc.), a desktop computer, a mobile computer, a laptop computer, an ultrabook™ computer, a notebook computer, a tablet computer, a server computer, a handheld computer, a handheld device, an internet of things (IoT) device, a sensor device, a PDA device, a handheld PDA device, an on-board device, an off-board device, a hybrid device (e.g., combining cellular phone functionalities with PDA device functionalities), a consumer device, a vehicular device, a non-vehicular device, a mobile or portable device, a non-mobile or non-portable device, a mobile phone, a cellular telephone, a PCS device, a PDA device which incorporates a wireless network interface, a mobile or portable GPS device, a DVB device, a relatively small computing device, a non-desktop computer, a “carry small live large” (CSLL) device, an ultra mobile device (UMD), an ultra mobile PC (UMPC), a mobile internet device (MID), an “origami” device or computing device, a device that supports dynamically composable computing (DCC), a context-aware device, a video device, an audio device, an A/V device, a set-top-box (STB), a blu-ray disc (BD) player, a BD recorder, a digital video disc (DVD) player, a high definition (HD) DVD player, a DVD recorder, a HD DVD recorder, a personal video recorder (PVR), a broadcast HD receiver, a video source, an audio source, a video sink, an audio sink, a stereo tuner, a broadcast radio receiver, a flat panel display, a personal media player (PMP), a digital video camera (DVC), a digital audio player, a speaker, an audio receiver, an audio amplifier, a gaming device, a data source, a data sink, a digital still camera (DSC), a media player, a smartphone, a television, a music player, or the like. Other devices, including smart devices such as lamps, climate control, car components, household components, appliances, etc. may also be included in this list. 
     As used herein, the term “Internet of Things (IoT) device” is used to refer to any obj ect (e.g., an appliance, a sensor, etc.) that has an addressable interface (e.g., an Internet protocol (IP) address, a Bluetooth identifier (ID), a near-field communication (NFC) ID, etc.) and can transmit information to one or more other devices over a wired or wireless connection. An IoT device may have a passive communication interface, such as a quick response (QR) code, a radio-frequency identification (RFID) tag, an NFC tag, or the like, or an active communication interface, such as a modem, a transceiver, a transmitter-receiver, or the like. An IoT device can have a particular set of attributes (e.g., a device state or status, such as whether the IoT device is on or off, open or closed, idle or active, available for task execution or busy, and so on, a cooling or heating function, an environmental monitoring or recording function, a light-emitting function, a sound-emitting function, etc.) that can be embedded in and/or controlled/monitored by a central processing unit (CPU), microprocessor, ASIC, or the like, and configured for connection to an IoT network such as a local ad-hoc network or the Internet. For example, IoT devices may include, but are not limited to, refrigerators, toasters, ovens, microwaves, freezers, dishwashers, dishes, hand tools, clothes washers, clothes dryers, furnaces, air conditioners, thermostats, televisions, light fixtures, vacuum cleaners, sprinklers, electricity meters, gas meters, etc., so long as the devices are equipped with an addressable communications interface for communicating with the IoT network. IoT devices may also include cell phones, desktop computers, laptop computers, tablet computers, personal digital assistants (PDAs), etc. Accordingly, the IoT network may be comprised of a combination of “legacy” Internet-accessible devices (e.g., laptop or desktop computers, cell phones, etc.) in addition to devices that do not typically have Internet-connectivity (e.g., dishwashers, etc.). 
     In some embodiments, the user device(s)  1020  and/or AP-MLDs  1005  and  1027  may also include mesh stations in, for example, a mesh network, in accordance with one or more IEEE 802.11 standards and/or 3GPP standards. 
     Any of the user device(s)  1020  (e.g., user devices  1024 ,  1025 ,  1026 ,  1028 , and  1029 ) and AP-MLDs  1005  and  1027  may be configured to communicate with each other via one or more communications networks  1030  and/or  1035  wirelessly or wired. In some embodiments, the user device(s)  1020  may also communicate peer-to-peer or directly with each other with or without the AP-MLDs  1005  and  1027  and, in some embodiments, the user device(s)  1020  may also communicate peer-to-peer if enabled by the AP-MLDs  1005  and  1027 . 
     Furthermore, the AP-MLDs  1005  and  1027  may each comprise transition logic circuitry to implement link transition protocols, procedures, frames, mapping, and/or the like as discussed herein to transition quickly between links associated with AP MLDS of a non-collocated AP MLD  1004 . In the present embodiment, the AP-MLDs  1005  and  1027  may comprise 2.4 GHz, 5 GHz, and 6 GHz STAs. Note that embodiments are not limited to STAs capable of any particular set of carrier frequencies and the STAs of AP MLDs that are part of the non-collocated AP MLD  1004  are not required to have sets of STAs with the same carrier frequencies. Note also that the non-collocated AP MLD  1004  is not limited to inclusion of two AP MLDs. The non-collocated AP MLD  1004  may include more than two AP MLDs or may include all AP MLDs in a BSS or ESS. 
     The transition logic circuitry of the non-AP MLDs such as the user devices  1020  and the AP-MLDs  1005  and  1027  may implement transition protocols to enable the non-AP MLDs such as the laptop  1025  to advantageously transition links between the AP MLDs  1005  and  1027 . In the present embodiment, a collocated non-AP MLD, laptop  1025 , may determine to transition links from the AP MLD  1005  to the AP MLD  1027  via wireless communications media such as a 2.4 GHz link via a 2.4 GHz channel, a 5 GHz link via a 5 GHz channel, and a 6 GHz link via a 6 GHz channel. In some embodiments, the transition logic circuitry of a multiple medium access control (MAC) station management entity (SME) (MM-SME) and one or more STA SMEs of the laptop  1025  may determine field values for and cause transmission of a MAC (re)association frame  1021  via a physical layer (PHY) frame to the AP MLD  1005 . The MM-SME may be a component of station management of a MLD (such as non-AP MLDs and AP MLDs) that manages multiple cooperating, collocated STAs of the MLD. 
     The transition logic circuitry of the laptop  1025  may determine to transmit the MAC (re)association frame  1021  may be a MAC management frame and may comprise fields such as the MAC management frames shown in  FIGS.  2 F and  2 R . The transition logic circuitry of the laptop  1025  may comprise information about the AP MLD  1027  of the non-collocated AP MLD  1004  based on receipt of a beacon frame, a probe response frame, one or more other discovery and/or advertisement frames, and/or the like. The transition logic circuitry of the laptop  1025  may determine a value of an add link field in the frame header or the frame body of the (re)association request frame  1021  to indicate that the request is made to add new links without changing current links. The value of the add link field may include one or more bits and may include a first value to indicate that the request is made to add new links only or a second value to indicate that the request is not made to add new links only. 
     The transition logic circuitry of the laptop  1025  may determine a value of a field to identify the non-collocated AP MLD  1004  as a recipient of the (re)association request frame  1021  in addition to an address field to identify a collocated AP MLD via a recipient address (RA). In some embodiments, the transition logic circuitry of the laptop  1025  may determine the value as a MAC address for the non-collocated AP MLD  1004 . In some embodiments, the transition logic circuitry of the laptop  1025  may determine the value as a MAC ID for the non-collocated AP MLD  1004 . In some embodiments, the transition logic circuitry of the laptop  1025  may determine the value of a flag indicative of the non-collocated AP MLD  1004  being the recipient rather than the AP MLD  1005  to which the (re)association request frame  1021  is also addressed with the RA. In some embodiments, the transition logic circuitry of the laptop  1025  may determine more than one or all the values for the MAC address, MAC ID, and the flag for inclusion in the (re)association request frame  1021 . 
     In some embodiments, the transition logic circuitry of the laptop  1025  may generate the (re)association request frame  1021  with a new field in the core of the authentication frame such as a recipient MAC address field or a recipient ID field and include the value of the MAC address, the MAC ID, and/or the flag in the recipient MAC address field or the recipient ID field. In some embodiments, the transition logic circuitry may generate a new field referred to as a non-collocated field for inclusion of the value of the flag. The flag may comprise one bit to indicate whether the (re)association request frame  1021  is transmitted to the AP MLD  1005  or to the non-collocated AP MLD  1004 . For instance, the value of the one bit may be set to a logical one to indicate that the (re)association request frame  1021  is addressed for the non-collocated AP MLD  1004 , set to a logical zero to indicate that the (re)association request frame  1021  is addressed for the AP MLD  1005 , or vice versa. In other embodiments, the flag may include more than one bit such as two bits, three bits, four bits, or more bits to include the value of the flag and, optionally, other information. 
     In many embodiments, the add link filed, recipient MAC address field, the recipient ID field, or the non-collocated field may be included in the frame header of the (re)association request frame  1021 . In some of such embodiments, the add link field, MAC address field, the recipient ID field, or the non-collocated field may be included in the frame control field of the frame header of the (re)association request frame  1021 . In other embodiments, the add link field, the recipient MAC address field, the recipient ID field, or the non-collocated field may be included in the frame body of the (re)association request frame  1021  such as a field included in the frame body or in an element included in the frame body. In some embodiments, the add link field, the recipient MAC address field, the recipient ID field, or the non-collocated field may be included in a common info field of a ML element of the frame body of the (re)association request frame  1021 . Note that a (re)association response frame  1022  may also be addressed in the same way as the (re)association request frame  1021  via an address field for an RA and a new field with a MAC address, MLD ID, and/or a flag to identify the non-collocated AP MLD  1004  in the frame header or the frame body of the (re)association response frame  1022 . 
     Similar to the (re)association request frame  1021 , the recipient MAC address field, the recipient ID field, or the non-collocated field may be included in the frame header of the TID-to-Link mapping request/response frame  1023  or the frame body of the TID-to-Link mapping request/response frame  1023  with the value of the MAC Address, MLD ID, and/or flag indicative of the non-collocated AP MLD  1004 . In some of such embodiments, the MAC address field, the recipient ID field, or the non-collocated field may be included in the frame control field of the frame header of the TID-to-Link mapping request/response frame  1023 . 
     After transmission of the (re)association request frame  1021 , the laptop  1025  may receive a (re)association response frame  1022  that includes new link IDs for each of the added links for the AP MLD  1027 . The new link IDs may reside in per-STA profile subelements of a ML element in the frame body of the (re)association response frame  1022 . 
     After successful addition of the new links between the laptop  1025  and the AP MLD  1027 , the transition logic circuitry of the laptop  1025  may transmit a TID-to-Link mapping request frame  1023  to the AP MLD  1005  and receive a TID-to-Link mapping response frame  1023  from the AP MLD  1005  to enable the new links between the non-AP STAs of the laptop  1025  and the AP STAs of the AP MLD  1027 . The TID-to-Link mapping request frame  1023  may include a bitmap for links to associate with one or more traffic identifiers (TIDs) to with the link IDs of the new links between the non-AP STAs of the laptop  1025  and the AP STAs of the AP MLD  1027   to enable the new links. In some embodiments, the bitmap for links may reside in a TID-to-Link mapping element and may not include link IDs of the old links between the laptop  1025  and AP MLD  1005 . The exclusion of the links in the bitmaps of links for each of the one or more TIDs may remove the TIDs from the old links, disabling the old links between the non-AP STAs of the laptop  1025  and the AP STAs of the AP MLD  1005 . 
     The transition logic circuitry of the AP MLD  1005  may respond to the TID-to-Link mapping request  1023  with a TID-to-Link mapping response  1023  to indicate whether negotiation of the TID-to-Link mapping was successful. If successful, the new links between the laptop  1025  and AP MLD  1027  are setup, and the old links may be removed or torn down. 
     To tear down the old links between the laptop  1025  and AP MLD  1005 , the transition logic circuitry of the laptop  1025  may transmit a MAC frame such as a new MAC frame, a (re)association request frame, a disassociation frame, or the like with an address field to identify the AP MLD  1027 , a recipient MAC address or recipient ID field to identify the non-collocated AP MLD  1004 , and link IDs of the old links between the laptop  1025  and AP MLD  1005  in per-STA profile subelements of a multi-link element to identify the old links to remove. 
     Note that the example includes AP STAs for both AP MLDs  1005  and  1027  of the non-collocated AP MLD  1004  but embodiments are not so limited. The per-STA profile subelements can identify any AP STA of any AP MLD that is associated with the non-collocated AP MLD  1004  that has matching operating capabilities and parameters such as the same carrier frequencies, modulation and coding capabilities, operating parameters, and/or the like. Furthermore, the laptop  1025  may transition all links with the same AP MLD of the non-collocation AP MLD  1004  such as AP MLD  1005  at the same time or may transition one or more links individually. 
     The transition logic circuitry of the AP MLD  1027  may respond to the MAC frame transmitted by the laptop  1025  to remove the old links with a response indicating success or failure to perform the removal procedure. In other embodiments, the AP MLD  1005  or the AP MLD  1027  may initiate the removal of the old links in response to completion of the enablement of the new links and disablement of the old links and transmit a MAC frame to the laptop  1025  to indicate successful removal of the old links between the laptop  1025  and AP MLD  1005 . 
     After the removal of the old links, in some embodiments, the links IDs of the laptop  1025  may be re-set by a disassociation procedure initiated by the AP MLD  1005  or the AP MLD  1027 . In other embodiments, the AP MLD  1005  or the AP MLD  1027  may transmit a MAC frame such as a (re)association response frame to the laptop  1025  to re-set the link IDs maintained by the laptop  1025 . The MAC frame may include the new link IDs in per-STA profile subelements of a multi-link element along with information that changed between the old links and the new links such as channel information, modulation and coding schemes, medium synchronization delay information, MLD capabilities and operations EML capabilities, other operating parameters, and/or the like. 
     Any of the communications networks  1030  and/or  1035  may include, but not limited to, any one of a combination of different types of suitable communications networks such as, for example, broadcasting networks, cable networks, public networks (e.g., the Internet), private networks, wireless networks, cellular networks, or any other suitable private and/or public networks. Further, any of the communications networks  1030  and/or  1035  may have any suitable communication range associated therewith and may include, for example, global networks (e.g., the Internet), metropolitan area networks (MANs), wide area networks (WANs), local area networks (LANs), or personal area networks (PANs). In addition, any of the communications networks  1030  and/or  1035  may include any type of medium over which network traffic may be carried including, but not limited to, coaxial cable, twisted-pair wire, optical fiber, a hybrid fiber coaxial (HFC) medium, microwave terrestrial transceivers, radio frequency communication mediums, white space communication mediums, ultra-high frequency communication mediums, satellite communication mediums, or any combination thereof. 
     Any of the user device(s)  1020  (e.g., user devices  1024 ,  1025 ,  1026 ,  1028 , and  1029 ), the AP MLD  1005 , and the AP-MLD  1027  may include one or more communications antennas. The one or more communications antennas may be any suitable type of antennas corresponding to the communications protocols used by the user device(s)  1020  (e.g., user devices  1024 ,  1025 ,  1026 ,  1028 , and  1029 ) and AP-MLD  1005 . Some non-limiting examples of suitable communications antennas include Wi-Fi antennas, Institute of Electrical and Electronics Engineers (IEEE) 802.11 family of standards compatible antennas, directional antennas, non-directional antennas, dipole antennas, folded dipole antennas, patch antennas, multiple-input multiple-output (MIMO) antennas, omnidirectional antennas, quasi-omnidirectional antennas, or the like. The one or more communications antennas may be communicatively coupled to a radio component to transmit and/or receive signals, such as communications signals to and/or from the user devices  1020 , AP MLD  1005 , and/or AP-MLD  1027 . 
     Any of the user device(s)  1020  (e.g., user devices  1024 ,  1025 ,  1026 ,  1028 , and  1029 ), the AP MLD  1005 , and AP-MLD  1027  may be configured to wirelessly communicate in a wireless network. Any of the user device(s)  1020  (e.g., user devices  1024 ,  1025 ,  1026 ,  1028 , and  1029 ), the AP MLD  1005 , and AP-MLD  1027  may be configured to perform such directional transmission and/or reception using a set of multiple antenna arrays (e.g., DMG antenna arrays or the like). Each of the multiple antenna arrays may be used for transmission and/or reception in a particular respective direction or range of directions. Any of the user device(s)  1020  (e.g., user devices  1024 ,  1025 ,  1026 ,  1028 , and  1029 ), the AP MLD  1005 , and AP-MLD  1027  may be configured to perform any given directional transmission towards one or more defined transmit sectors. Any of the user device(s)  1020  (e.g., user devices  1024 ,  1025 ,  1026 ,  1028 , and  1029 ), the AP MLD  1005 , and AP-MLD  1027  may be configured to perform any given directional reception from one or more defined receive sectors. 
     MIMO beamforming in a wireless network may be accomplished using RF beamforming and/or digital beamforming. In some embodiments, in performing a given MIMO transmission, user devices  1020 , AP MLD  1005 , and/or AP-MLD  1027  may be configured to use all or a subset of its one or more communications antennas to perform MIMO beamforming. 
     Any of the user devices  1020  (e.g., user devices  1024 ,  1025 ,  1026 ,  1028 , and  1029 ), the AP MLD  1005 , and AP-MLD  1027  may include any suitable radio and/or transceiver for transmitting and/or receiving radio frequency (RF) signals in the bandwidth and/or channels corresponding to the communications protocols utilized by any of the user device(s)  1020  and AP-MLD  1005  to communicate with each other. The radio components may include hardware and/or software to modulate and/or demodulate communications signals according to pre-established transmission protocols. The radio components may further have hardware and/or software instructions to communicate via one or more Wi-Fi and/or Wi-Fi direct protocols, as standardized by the Institute of Electrical and Electronics Engineers (IEEE) 802.11 standards. In certain example embodiments, the radio component, in cooperation with the communications antennas, may be configured to communicate via 2.4 GHz channels (e.g., 802.11b, 802.11g, 802.11n, 802.1 1ax, 802.11be), 5 GHz channels (e.g., 802.11n, 802.11ac, 802.11ax, 802.1 1be), 6 GHz (e.g., 802.11be), or 60 GHz channels (e.g., 802.11ad, 802.11ay, Next Generation Wi-Fi) or 800 MHz channels (e.g., 802.1 1ah). The communications antennas may operate at 28 GHz, 40 GHz, or any carrier frequency between 45 GHz and 75 GHz. It should be understood that this list of communication channels in accordance with certain 802.11 standards is only a partial list, and that other 802.11 standards may be used (e.g., Next Generation Wi-Fi, or other standards). In some embodiments, non-Wi-Fi protocols may be used for communications between devices, such as Bluetooth, dedicated short-range communication (DSRC), Ultra-High Frequency (UHF) (e.g., IEEE 802.11af, IEEE 802.22), white band frequency (e.g., white spaces), or other packetized radio communications. The radio component may include any known receiver and baseband suitable for communicating via the communications protocols. The radio component may further include a power amplifier (PA), a low noise amplifier (LNA), additional signal amplifiers, an analog-to-digital (A/D) converter, one or more buffers, and a digital baseband. 
       FIG.  1 B  depicts an embodiment  1100  illustrating interactions between stations (STAs) to transition a non-AP MLD  1130  from multiple links with an access point (AP) ML device (MLD)  1120  to multiple links with an AP MLD  1150 . The AP MLD  1120  has three collocated affiliated AP STAs: AP STA 1 operates on 2.4 GHz band, AP STA 2 operates on 5 GHz band, and AP STA 3 operates on 6 GHz band. The AP MLD  1120  is also affiliated with a non-collocated AP MLD  1160  and a collocated AP MLD  1150  that is also affiliated with the non-collocated AP MLD  1160 . The AP MLD  1150  also has three collocated affiliated AP STAs: AP STA 4 operates on 2.4 GHz band, AP STA 5 operates on 5 GHz band, and AP STA 6 operates on 6 GHz band. 
     The pre-transition state  1100  depicts the non-AP MLD  1120  having three links (links 1-3) established between the non-AP MLD  1130  and the AP MLD  1120 . The post-association state  1110  depicts the non-AP MLD  1120  with three links (links 4-6) established between the non-AP MLD  1130  and the AP MLD  1150 . 
     The transition logic circuitry of the non-AP MLD  1130 , the AP MLD  1120 , and the AP MLD  1150  may perform the transition in three or four phases: an optional pre-transition phase, a link add phase, a link enablement/disablement phase, and a link removal phase. The optional pre-transition phase may, advantageously increase the speed (reduce any delays associated with) the transition. During the pre-transition phase, the non-AP MLD may transmit a MAC frame to the AP MLD  1120  to inform the transition logic circuitry of the AP MLD  1120  of the pending transition of links between the non-AP MLD and the AP MLD  1120  to new links between the non-AP MLD and the AP MLD  1150 . In response to the MAC frame, the transition logic circuitry of the AP MLD  1120  may transmit one or more updates of the buffer status and scoreboard for Bus of maintained by the AP MLD  1120  to the AP MLD  1150 . 
     At the start of the transition, before the start of the transition, or at an event prior to the transition, the non-AP MLD  1130  may transmit one or more block acknowledgements (BAs) to the AP MLD  1150  responsive to BU downlinks (DLs) to inform the AP MLD  1150  of the recently completed DLs between the non-AP MLD  1130  and the AP MLD  1120 . In some embodiments, the non-AP MLD  1130  may also transmit a buffer status for uplinks (ULs) pending at the non-AP MLD. 
     During the add link phase, the non-AP MLD  1130  may transmit a (re)association request frame to the AP MLD  1130  to identify new links to add or setup between the non-AP MLD  1130  and the AP MLD  1150 . The (re)association request frame may include an add link flag in the frame header or frame body of the (re)association request frame to indicate that the (re)association request frame requests only that new links be added, and current links be maintained. The (re)association request frame may also include an address field for an RA identifying the AP MLD  1120  and a recipient MAC address or MLD ID field in the frame header or in a multi-link element in the frame body to identify the non-collocated AP MLD  1160  as a recipient of the (re)association request frame. In per-STA profile subelements of the multi-link element of (re)association request frame, the non-AP MLD may identify links to add with STA MAC addresses and link IDs for the AP MLD  1150 . 
     The AP MLD  1120  may respond to the (re)association request frame with a (re)association response frame indicating the successful addition of the new links between the non-AP MLD  1130  and the AP MLD  1150  and may include new link IDs generated for representation of the new links in per-STA profile subelements of a link info field of the multi-link element of the (re)association response frame. In many embodiments, the AP MLD  1120  may also generate a mapping table with entries for each of the new link IDs that associates each of the new link IDs with corresponding STA MAC addresses and link IDs for the AP MLD  1150 . 
     During the link enablement/disablement phase, the non-AP MLD may transmit one or more TID-to-Link request frames to the AP MLD  1120  with bitmaps for links to associate with traffic identifiers (TIDs) the new links between the non-AP STAs of the non-AP MLD  1130  and the AP STAs of the AP MLD  1150  and that do not associate the old links with TIDs between the non-AP STAs of the non-AP MLD  1130  and the AP STAs of the AP MLD  1120 . Adding the new links to the bitmaps of links for the TIDs may enable the new links and removal of the old links in the bitmaps for the TIDs may disable the old links. In some embodiments, the new links are added to the bitmaps of links for the TIDs in a first frame exchange such that all the links are enabled and the old links are removed from the from the bitmaps of links for the TIDs in a second frame exchange of TID-to-Link request and response frames. In other embodiments, the enablement and disablement may be accomplished in a single frame exchange, e.g., transmission of one TID-to-Link request frame and receipt of one TID-to-Link response frame by the non-AP MLD. 
     After the transmission of a TID-to-Link request frame, the AP MLD  1120  may respond with a TID-to-Link response frame that includes a status code that indicates whether or not the change in the assignment of TIDs to links is successful. 
     During the link removal phase, in some embodiments, the old links between the non-AP MLD  1130  and the AP MLD  1150  are removed or tore down via a (re)association request frame from the non-AP MLD to the AP MLD  1150 , a new MAC request frame from the non-AP MLD  1130  to the AP MLD  1150 , or a disassociation frame from the non-AP MLD  1130  to the AP MLD  1150  based on identification of the old links with link IDs in per-STA profile subelements of a of a multi-link element in the frame. In other embodiments, transition logic circuitry of the AP MLD  1120  or the AP MLD  1150  may tear down the old links after the enablement/disablement phase. 
     In some embodiments, the link removal phase may also include a link re-set phase for the non-AP MLD  1130 . The process of re-setting the link IDs for the non-AP MLD  1130  by the AP MLD  1120  or  1150  may be performed along with a disassociation procedure if there is a response from the AP MLD  1120  or  1150  and the disassociation procedure was initiated by the non-AP MLD  1130 . The non-AP MLD  1130  may initiated the link removal or link deletion by transmitting a (re)association request frame or a disassociation frame that includes a remove links field to indicate the link removal procedure and per-STA profile subelements to identify the links to remove. 
     In some embodiments, the process of re-setting the link IDs for the non-AP MLD  1130  may be performed along with a disassociation procedure if the process is initiated by the AP MLD  1120  or  1150 . Re-setting the link IDs for the non-AP MLD may be performed by including the information for each link that is changed of the old link ID and the new link ID. 
       FIG.  1 C  depicts an embodiment of a system  1200  including multiple MLDs to implement transition logic circuitry, in accordance with one or more example embodiments. System  1200  may transmit or receive as well as generate, decode, and interpret transmissions between an AP MLD  1210  and multiple MLDs  1230 ,  1290 ,  1292 ,  1294 ,  1296 , and  1298 , associated with the AP MLD  1210 . The AP MLD  1210  may be wired and wirelessly connected to each of the MLDs  1230 ,  1290 ,  1292 ,  1294 ,  1296 , and  1298 . 
     In some embodiments, the AP MLD  1210  may one of multiple AP MLDs affiliated with a collocated AP MLD (not shown) and MLD  1230  may include one or more computer systems similar to that of the example machines/systems of  FIGS.  5 ,  6 ,  7 , and  8   . 
     Each MLD  1230 ,  1290 ,  1292 ,  1294 ,  1296 , and  1298  may include transition logic circuitry, such as the transition logic circuitry  1250  of MLD  1230 , to transition links between a non-AP MLD and a first AP MLD (AP MLD  1210 ) affiliated with the non-collocated AP MLD to links between the non-AP MLD and a second AP MLD (not shown) affiliated with the non-collocated AP MLD via the AP MLD  1210 . 
     Each of the MLDs  1230 ,  1290 ,  1292 ,  1294 ,  1296 , and  1298  may transmit an association request frame or reassociation request frame to the AP MLD  1210  and include in the request frame a flag to indicate a MAC address for the non-collocated AP MLD, an MLD ID for the non-collocated AP MLD, or a flag to signal that the (re)association request frame, while addressed to the AP MLD  1210  in the RA, is a request addressed for the non-collocated AP MLD. 
     The (re)association request frame may comprise per-STA profile subelements that identify AP STAs of one or more other AP MLDs affiliated with the non-collocated MLD. The AP MLD  1210  may generate and transmit a (re)association response frame responsive to each of the (re)association request frames, indicative of success or failure to add links with the non-collocated AP MLD between the non-AP MLD and the one or more other AP MLDs. The (re)association response frames may include link IDs created to represent links between the MLDs  1230 ,  1290 ,  1292 ,  1294 ,  1296 , and  1298  and the one or more other AP MLDs that are affiliated with the non-collocated AP MLD. The AP MLD  1210  may also create a mapping table with entries for each of the link IDs to track the link IDs representative of links established between one or more AP STAs of other AP MLDs that are affiliated with the non-collocated AP MLD. In some embodiments, the AP MLD  1210  may include the link IDs representative of links established between one or more AP STAs of other AP MLDs that are affiliated with the non-collocated AP MLD, in a non-collocated link ID field in per-STA profile subelements of a ML element in the association response frames transmitted to the MLDs  1230 ,  1290 ,  1292 ,  1294 ,  1296 , and  1298 . 
     The AP MLD  1210  and MLD  1230  may comprise processor(s)  1201  and memory  1231 , respectively. The processor(s)  1201  may comprise any data processing device such as a microprocessor, a microcontroller, a state machine, and/or the like, and may execute instructions or code in the memory  1211 . The memory  1211  may comprise a storage medium such as Dynamic Random Access Memory (DRAM), read only memory (ROM), buffers, registers, cache, flash memory, hard disk drives, solid-state drives, or the like. The memory  1211  may store the frames, frame structures, frame headers, etc.,  1212  and may also comprise code to generate, scramble, encode, decode, parse, and interpret MAC frames and/or PHY frames and physical layer protocol data units (PPDUs). 
     The baseband processing circuitry  1218  may comprise a baseband processor and/or one or more circuits to implement an MLD station management entity (MM-SME) and a station management entity (SME) per link. The MM-SME may coordinate management of, communications between, and interactions between SMEs for the links. 
     In some embodiments, the SME may interact with a MAC layer management entity to perform MAC layer functionality and a PHY management entity to perform PHY functionality. In such embodiments, the baseband processing circuitry  1218  may interact with processor(s)  1201  to coordinate higher layer functionality with MAC layer and PHY functionality. 
     In some embodiments, the baseband processing circuitry  1218  may interact with one or more analog devices to perform PHY functionality such as scrambling, encoding, modulating, and the like. In other embodiments, the baseband processing circuitry  1218  may execute code to perform one or more of the PHY functionality such as scrambling, encoding, modulating, and the like. 
     The MAC layer functionality may execute MAC layer code stored in the memory  1211 . In further embodiments, the MAC layer functionality may interface the processor(s)  1201 . 
     The MAC layer functionality may communicate with the PHY via the SME to transmit a MAC frame such as a multiple-user (MU) ready to send (RTS), referred to as a MU-RTS, in a PHY frame such as an extremely high throughput (EHT) MU PPDU to the MLD  1230 . The MAC layer functionality may generate frames such as management, data, and control frames. 
     The PHY may prepare the MAC frame for transmission by, e.g., determining a preamble to prepend to a MAC frame to create a PHY frame. The preamble may include one or more short training field (STF) values, long training field (LTF) values, and signal (SIG) field values. A wireless network interface  1222  or the baseband processing circuitry  1218  may prepare the PHY frame as a scrambled, encoded, modulated PPDU in the time domain signals for the radio  1224 . Furthermore, the TSF timer  1205  may provide a timestamp value to indicate the time at which the PPDU is transmitted. 
     After processing the PHY frame, a radio  1225  may impress digital data onto subcarriers of RF frequencies for transmission by electromagnetic radiation via elements of an antenna array or antennas  1224  and via the network  1280  to a receiving MLD STA of a MLD such as the MLD  1230 . 
     The wireless network I/F  1222  also comprises a receiver. The receiver receives electromagnetic energy, extracts the digital data, and the analog PHY and/or the baseband processor  1218  decodes a PHY frame and a MAC frame from a PPDU. 
     The MLD  1230  may receive a PPDU of the EHT MU PPDU from the AP MLD  1210  via the network  1280 . The MLD  1230  may comprise processor(s)  1231  and memory  1241 . The processor(s)  1231  may comprise any data processing device such as a microprocessor, a microcontroller, a state machine, and/or the like, and may execute instructions or code in the memory  1241 . The memory  1241  may comprise a storage medium such as Dynamic Random Access Memory (DRAM), read only memory (ROM), buffers, registers, cache, flash memory, hard disk drives, solid-state drives, or the like. The memory  1241  may store  1242  the frames, frame structures, frame headers, etc., and may also comprise code to generate, scramble, encode, decode, parse, and interpret MAC frames and/or PHY frames (PPDUs). 
     The baseband processing circuitry  1248  may comprise a baseband processor and/or one or more circuits to implement a SME and the SME may interact with a MAC layer management entity to perform MAC layer functionality and a PHY management entity to perform PHY functionality. In such embodiments, the baseband processing circuitry  1248  may interact with processor(s)  1231  to coordinate higher layer functionality with MAC layer and PHY functionality. 
     In some embodiments, the baseband processing circuitry  1218  may interact with one or more analog devices to perform PHY functionality such as descrambling, decoding, demodulating, and the like. In other embodiments, the baseband processing circuitry  1218  may execute code to perform one or more of the PHY functionalities such as descrambling, decoding, demodulating, and the like. 
     The MLD  1230  may receive the PPDU of the EHT MU PPDU at the antennas  1258 , which pass the signals along to the FEM  1256 . The FEM  1256  may amplify and filter the signals and pass the signals to the radio  1254 . The radio  1254  may filter the carrier signals from the signals and determine if the signals represent a PPDU. If so, analog circuitry of the wireless network I/F  1252  or physical layer functionality implemented in the baseband processing circuitry  1248  may demodulate, decode, descramble, etc. the PPDU. The baseband processing circuitry  1248  may identify, parse, and interpret a MAC service data unit (MSDU) from the physical layer service data unit (PSDU) of the EHT MU PPDU. 
       FIG.  1 D  is a block diagram of a radio architecture  1300  such as the wireless communications I/F  1222  and  1252  in accordance with some embodiments that may be implemented in, e.g., the AP MLD  1210  and/or the MLD  1230  of  FIG.  1 C . The radio architecture  1300  may include radio front-end module (FEM) circuitry  1304   a - b , radio IC circuitry  1306   a - b  and baseband processing circuitry  1308   a - b . The radio architecture  1300  as shown includes both Wireless Local Area Network (WLAN) functionality and Bluetooth (BT) functionality although embodiments are not so limited. In this disclosure, “WLAN” and “Wi-Fi” are used interchangeably. 
     FEM circuitry  1304   a - b  may include a WLAN or Wi-Fi FEM circuitry  1304   a  and a Bluetooth (BT) FEM circuitry  1304   b . The WLAN FEM circuitry  1304   a  may include a receive signal path comprising circuitry configured to operate on WLAN RF signals received from one or more antennas  1301 , to amplify the received signals and to provide the amplified versions of the received signals to the WLAN radio IC circuitry  1306   a  for further processing. The BT FEM circuitry  1304   b  may include a receive signal path which may include circuitry configured to operate on BT RF signals received from one or more antennas  1301 , to amplify the received signals and to provide the amplified versions of the received signals to the BT radio IC circuitry  1306   b  for further processing. FEM circuitry  1304   a  may also include a transmit signal path which may include circuitry configured to amplify WLAN signals provided by the radio IC circuitry  1306   a  for wireless transmission by one or more of the antennas  1301 . In addition, FEM circuitry  1304   b  may also include a transmit signal path which may include circuitry configured to amplify BT signals provided by the radio IC circuitry  1306   b  for wireless transmission by the one or more antennas. In the embodiment of  FIG.  1 D , although FEM  1304   a  and FEM  1304   b  are shown as being distinct from one another, embodiments are not so limited, and include within their scope the use of an FEM (not shown) that includes a transmit path and/or a receive path for both WLAN and BT signals, or the use of one or more FEM circuitries where at least some of the FEM circuitries share transmit and/or receive signal paths for both WLAN and BT signals. 
     Radio IC circuitry  1306   a - b  as shown may include WLAN radio IC circuitry  1306   a  and BT radio IC circuitry  1306   b . The WLAN radio IC circuitry  1306   a  may include a receive signal path which may include circuitry to down-convert WLAN RF signals received from the FEM circuitry  1304   a  and provide baseband signals to WLAN baseband processing circuitry  1308   a . BT radio IC circuitry  1306   b  may in turn include a receive signal path which may include circuitry to down-convert BT RF signals received from the FEM circuitry  1304   b  and provide baseband signals to BT baseband processing circuitry  1308   b . WLAN radio IC circuitry  1306   a  may also include a transmit signal path which may include circuitry to up-convert WLAN baseband signals provided by the WLAN baseband processing circuitry  1308   a  and provide WLAN RF output signals to the FEM circuitry  1304   a  for subsequent wireless transmission by the one or more antennas  1301 . BT radio IC circuitry  1306   b  may also include a transmit signal path which may include circuitry to up-convert BT baseband signals provided by the BT baseband processing circuitry  1308   b  and provide BT RF output signals to the FEM circuitry  1304   b  for subsequent wireless transmission by the one or more antennas  1301 . In the embodiment of  FIG.  1 D , although radio IC circuitries  1306   a  and  1306   b  are shown as being distinct from one another, embodiments are not so limited, and include within their scope the use of a radio IC circuitry (not shown) that includes a transmit signal path and/or a receive signal path for both WLAN and BT signals, or the use of one or more radio IC circuitries where at least some of the radio IC circuitries share transmit and/or receive signal paths for both WLAN and BT signals. 
     Baseband processing circuity  1308   a - b  may include a WLAN baseband processing circuitry  1308   a  and a BT baseband processing circuitry  1308   b . The WLAN baseband processing circuitry  1308   a  may include a memory, such as, for example, a set of RAM arrays in a Fast Fourier Transform or Inverse Fast Fourier Transform block (not shown) of the WLAN baseband processing circuitry  1308   a . Each of the WLAN baseband circuitry  1308   a  and the BT baseband circuitry  1308   b  may further include one or more processors and control logic to process the signals received from the corresponding WLAN or BT receive signal path of the radio IC circuitry  1306   a - b , and to also generate corresponding WLAN or BT baseband signals for the transmit signal path of the radio IC circuitry  1306   a - b . Each of the baseband processing circuitries  1308   a  and  1308   b  may further include physical layer (PHY) and medium access control layer (MAC) circuitry, and may further interface with a device for generation and processing of the baseband signals and for controlling operations of the radio IC circuitry  1306   a - b . 
     Referring still to  FIG.  1 D , according to the shown embodiment, WLAN-BT coexistence circuitry  1313  may include logic providing an interface between the WLAN baseband circuitry  1308   a  and the BT baseband circuitry  1308   b  to enable use cases requiring WLAN and BT coexistence. In addition, a switch circuitry  1303  may be provided between the WLAN FEM circuitry  1304   a  and the BT FEM circuitry  1304   b  to allow switching between the WLAN and BT radios according to application needs. In addition, although the antennas  1301  are depicted as being respectively connected to the WLAN FEM circuitry  1304   a  and the BT FEM circuitry  1304   b , embodiments include within their scope the sharing of one or more antennas as between the WLAN and BT FEMs, or the provision of more than one antenna connected to each of FEM  1304   a  or  1304   b . 
     In some embodiments, the front-end module circuitry  1304   a - b , the radio IC circuitry  1306   a - b , and baseband processing circuitry  1308   a - b  may be provided on a single radio card, such as wireless network interface card (NIC)  1302 . In some other embodiments, the one or more antennas  1301 , the FEM circuitry  1304   a - b  and the radio IC circuitry  1306   a - b  may be provided on a single radio card. In some other embodiments, the radio IC circuitry  1306   a - b  and the baseband processing circuitry  1308   a - b  may be provided on a single chip or integrated circuit (IC), such as IC  1312 . 
     In some embodiments, the wireless NIC  1302  may include a WLAN radio card and may be configured for Wi-Fi communications, although the scope of the embodiments is not limited in this respect. In some of these embodiments, the radio architecture  1300  may be configured to receive and transmit orthogonal frequency division multiplexed (OFDM) or orthogonal frequency division multiple access (OFDMA) communication signals over a multicarrier communication channel. The OFDM or OFDMA signals may comprise a plurality of orthogonal subcarriers. 
     In some of these multicarrier embodiments, radio architecture  1300  may be part of a Wi-Fi communication station (STA) such as a wireless access point (AP), a base station or a mobile device including a Wi-Fi device. In some of these embodiments, radio architecture  1300  may be configured to transmit and receive signals in accordance with specific communication standards and/or protocols, such as any of the Institute of Electrical and Electronics Engineers (IEEE) standards including, 802.11n-2009, IEEE 802.11-2012, IEEE 802.11-2020, IEEE 802.1 1ay-2021, IEE 802.11ba-2021, IEEE 802.11ax-2021, and/or IEEE 802.11be standards and/or proposed specifications for WLANs, although the scope of embodiments is not limited in this respect. The radio architecture  1300  may also be suitable to transmit and/or receive communications in accordance with other techniques and standards. 
     In some embodiments, the radio architecture  1300  may be configured for high-efficiency Wi-Fi (HEW) communications in accordance with the IEEE 802.1 1ax-2021 standard. In these embodiments, the radio architecture  1300  may be configured to communicate in accordance with an OFDMA technique, although the scope of the embodiments is not limited in this respect. 
     In some other embodiments, the radio architecture  1300  may be configured to transmit and receive signals transmitted using one or more other modulation techniques such as spread spectrum modulation (e.g., direct sequence code division multiple access (DS-CDMA) and/or frequency hopping code division multiple access (FH-CDMA)), time-division multiplexing (TDM) modulation, and/or frequency-division multiplexing (FDM) modulation, although the scope of the embodiments is not limited in this respect. 
     In some embodiments, as further shown in  FIG.  1 D , the BT baseband circuitry  1308   b  may be compliant with a Bluetooth (BT) connectivity specification such as Bluetooth 5.0, or any other iteration of the Bluetooth specification. 
     In some embodiments, the radio architecture  1300  may include other radio cards, such as a cellular radio card configured for cellular (e.g., 5GPP such as LTE, LTE-Advanced or 7G communications). 
     In some IEEE 802.11 embodiments, the radio architecture  1300  may be configured for communication over various channel bandwidths including bandwidths having center frequencies of about 2.4 GHz, 5 GHz, and 6 GHz. The various bandwidths may include bandwidths of about 20 MHz, 40 MHz, 80 MHz, 160 MHz, 240 MHz, and 320 MHz with contiguous or non-contiguous bandwidths having increments of 20 MHz, 40 MHz, 80 MHz, 160 MHz, 240 MHz, and 320 MHz. The scope of the embodiments is not limited with respect to the above center frequencies, however. 
       FIG.  1 E  illustrates FEM circuitry  1400  such as WLAN FEM circuitry  1304   a  shown in  FIG.  1 D  in accordance with some embodiments. Although the example of  FIG.  1 E  is described in conjunction with the WLAN FEM circuitry  1304   a , the example of  FIG.  1 E  may be described in conjunction with other configurations such as the BT FEM circuitry  1304   b . 
     In some embodiments, the FEM circuitry  1400  may include a TX/RX switch  1402  to switch between transmit mode and receive mode operation. The FEM circuitry  1400  may include a receive signal path and a transmit signal path. The receive signal path of the FEM circuitry  1400  may include a low-noise amplifier (LNA)  1406  to amplify received RF signals  1403  and provide the amplified received RF signals  1407  as an output (e.g., to the radio IC circuitry  1306   a - b  ( FIG.  1 D )). The transmit signal path of the circuitry  1304   a  may include a power amplifier (PA) to amplify input RF signals  1409  (e.g., provided by the radio IC circuitry  1306   a - b ), and one or more filters  1412 , such as band-pass filters (BPFs), low-pass filters (LPFs) or other types of filters, to generate RF signals  1415  for subsequent transmission (e.g., by one or more of the antennas  1301  ( FIG.  1 D )) via an example duplexer  1414 . 
     In some dual-mode embodiments for Wi-Fi communication, the FEM circuitry  1400  may be configured to operate in the 2.4 GHz frequency spectrum, the 5 GHz frequency spectrum, or the 6 GHz frequency spectrum. In these embodiments, the receive signal path of the FEM circuitry  1400  may include a receive signal path duplexer  1404  to separate the signals from each spectrum as well as provide a separate LNA  1406  for each spectrum as shown. In these embodiments, the transmit signal path of the FEM circuitry  1400  may also include a power amplifier  1410  and a filter  1412 , such as a BPF, an LPF or another type of filter for each frequency spectrum and a transmit signal path duplexer  1404  to provide the signals of one of the different spectrums onto a single transmit path for subsequent transmission by the one or more of the antennas  1301  ( FIG.  1 D ). In some embodiments, BT communications may utilize the 2.4 GHz signal paths and may utilize the same FEM circuitry  1400  as the one used for WLAN communications. 
       FIG.  1 F  illustrates radio IC circuitry  1506   a  in accordance with some embodiments. The radio IC circuitry  1306   a  is one example of circuitry that may be suitable for use as the WLAN or BT radio IC circuitry  1306   a / 1306   b  ( FIG.  1 D ), although other circuitry configurations may also be suitable. Alternatively, the example of  FIG.  1 F  may be described in conjunction with the example BT radio IC circuitry  1306   b . 
     In some embodiments, the radio IC circuitry  1306   a  may include a receive signal path and a transmit signal path. The receive signal path of the radio IC circuitry  1306   a  may include at least mixer circuitry  1502 , such as, for example, down-conversion mixer circuitry, amplifier circuitry  1506  and filter circuitry  1508 . The transmit signal path of the radio IC circuitry  1306   a  may include at least filter circuitry  1512  and mixer circuitry  1514 , such as, for example, up-conversion mixer circuitry. Radio IC circuitry  1306   a  may also include synthesizer circuitry  1504  for synthesizing a frequency  1505  for use by the mixer circuitry  1502  and the mixer circuitry  1514 . The mixer circuitry  1502  and/or  1514  may each, according to some embodiments, be configured to provide direct conversion functionality. The latter type of circuitry presents a much simpler architecture as compared with standard super-heterodyne mixer circuitries, and any flicker noise brought about by the same may be alleviated for example through the use of OFDM modulation.  FIG.  1 F  illustrates only a simplified version of a radio IC circuitry, and may include, although not shown, embodiments where each of the depicted circuitries may include more than one component. For instance, mixer circuitry  1514  may each include one or more mixers, and filter circuitries  1508  and/or  1512  may each include one or more filters, such as one or more BPFs and/or LPFs according to application needs. For example, when mixer circuitries are of the direct-conversion type, they may each include two or more mixers. 
     In some embodiments, mixer circuitry  1502  may be configured to down-convert RF signals  1407  received from the FEM circuitry  1304   a - b  ( FIG.  1 D ) based on the synthesized frequency  1505  provided by synthesizer circuitry  1504 . The amplifier circuitry  1506  may be configured to amplify the down-converted signals and the filter circuitry  1508  may include an LPF configured to remove unwanted signals from the down-converted signals to generate output baseband signals  1507 . Output baseband signals  1507  may be provided to the baseband processing circuitry  1308   a - b  ( FIG.  1 D ) for further processing. In some embodiments, the output baseband signals  1507  may be zero-frequency baseband signals, although this is not a requirement. In some embodiments, mixer circuitry  1502  may comprise passive mixers, although the scope of the embodiments is not limited in this respect. 
     In some embodiments, the mixer circuitry  1514  may be configured to up-convert input baseband signals  1511  based on the synthesized frequency  1505  provided by the synthesizer circuitry  1504  to generate RF output signals  1409  for the FEM circuitry  1304   a - b . The baseband signals  1511  may be provided by the baseband processing circuitry  1308   a - b  and may be filtered by filter circuitry  1512 . The filter circuitry  1512  may include an LPF or a BPF, although the scope of the embodiments is not limited in this respect. 
     In some embodiments, the mixer circuitry  1502  and the mixer circuitry  1514  may each include two or more mixers and may be arranged for quadrature down-conversion and/or up-conversion respectively with the help of synthesizer  1504 . In some embodiments, the mixer circuitry  1502  and the mixer circuitry  1514  may each include two or more mixers each configured for image rejection (e.g., Hartley image rejection). In some embodiments, the mixer circuitry  1502  and the mixer circuitry  1514  may be arranged for direct down-conversion and/or direct up-conversion, respectively. In some embodiments, the mixer circuitry  1502  and the mixer circuitry  1514  may be configured for super-heterodyne operation, although this is not a requirement. 
     Mixer circuitry  1502  may comprise, according to one embodiment: quadrature passive mixers (e.g., for the in-phase (I) and quadrature phase (Q) paths). In such an embodiment, RF input signal  1407  from  FIG.  1 F  may be down-converted to provide I and Q baseband output signals to be sent to the baseband processor. 
     Quadrature passive mixers may be driven by zero and ninety-degree time-varying LO switching signals provided by a quadrature circuitry which may be configured to receive a LO frequency (fLO) from a local oscillator or a synthesizer, such as LO frequency  1505  of synthesizer  1504  ( FIG.  1 F ). In some embodiments, the LO frequency may be the carrier frequency, while in other embodiments, the LO frequency may be a fraction of the carrier frequency (e.g., one-half the carrier frequency, one-third the carrier frequency). In some embodiments, the zero and ninety-degree time-varying switching signals may be generated by the synthesizer, although the scope of the embodiments is not limited in this respect. 
     In some embodiments, the LO signals may differ in duty cycle (the percentage of one period in which the LO signal is high) and/or offset (the difference between start points of the period). In some embodiments, the LO signals may have an 85% duty cycle and an 80% offset. In some embodiments, each branch of the mixer circuitry (e.g., the in-phase (I) and quadrature phase (Q) path) may operate at an 80% duty cycle, which may result in a significant reduction is power consumption. 
     The RF input signal  1407  ( FIG.  1 E ) may comprise a balanced signal, although the scope of the embodiments is not limited in this respect. The I and Q baseband output signals may be provided to low-noise amplifier, such as amplifier circuitry  1506  ( FIG.  1 F ) or to filter circuitry  1508  ( FIG.  1 F ). 
     In some embodiments, the output baseband signals  1507  and the input baseband signals  1511  may be analog baseband signals, although the scope of the embodiments is not limited in this respect. In some alternate embodiments, the output baseband signals  1507  and the input baseband signals  1511  may be digital baseband signals. In these alternate embodiments, the radio IC circuitry may include analog-to-digital converter (ADC) and digital-to-analog converter (DAC) circuitry. 
     In some dual-mode embodiments, a separate radio IC circuitry may be provided for processing signals for each spectrum, or for other spectrums not mentioned here, although the scope of the embodiments is not limited in this respect. 
     In some embodiments, the synthesizer circuitry  1504  may be a fractional-N synthesizer or a fractional N/N+1 synthesizer, although the scope of the embodiments is not limited in this respect as other types of frequency synthesizers may be suitable. For example, synthesizer circuitry  1504  may be a delta-sigma synthesizer, a frequency multiplier, or a synthesizer comprising a phase-locked loop with a frequency divider. According to some embodiments, the synthesizer circuitry  1504  may include digital synthesizer circuitry. An advantage of using a digital synthesizer circuitry is that, although it may still include some analog components, its footprint may be scaled down much more than the footprint of an analog synthesizer circuitry. In some embodiments, frequency input into synthesizer circuity  1504  may be provided by a voltage-controlled oscillator (VCO), although that is not a requirement. A divider control input may further be provided by either of the baseband processing circuitry  1308   a - b  ( FIG.  1 D ) depending on the desired output frequency  1505 . In some embodiments, a divider control input (e.g., N) may be determined from a look-up table (e.g., within a Wi-Fi card) based on a channel number and a channel center frequency as determined or indicated by the example application processor  1310 . The application processor  1310  may include, or otherwise be connected to, one of the example secure signal converter  101  or the example received signal converter  103  (e.g., depending on which device the example radio architecture is implemented in). 
     In some embodiments, synthesizer circuitry  1504  may be configured to generate a carrier frequency as the output frequency  1505 , while in other embodiments, the output frequency  1505  may be a fraction of the carrier frequency (e.g., one-half the carrier frequency, one-third the carrier frequency). In some embodiments, the output frequency  1505  may be a LO frequency (fLO). 
       FIG.  1 G  illustrates a functional block diagram of baseband processing circuitry  1308   a  in accordance with some embodiments. The baseband processing circuitry  1308   a  is one example of circuitry that may be suitable for use as the baseband processing circuitry  1308   a  ( FIG.  1 D ), although other circuitry configurations may also be suitable. Alternatively, the example of  FIG.  1 F  may be used to implement the example BT baseband processing circuitry  1308   b  of  FIG.  1 D . 
     The baseband processing circuitry  1308   a  may include a receive baseband processor (RX BBP)  1602  for processing receive baseband signals  1509  provided by the radio IC circuitry  1306   a - b  ( FIG.  1 D ) and a transmit baseband processor (TX BBP)  1604  for generating transmit baseband signals  1511  for the radio IC circuitry  1306   a - b . The baseband processing circuitry  1308   a  may also include control logic  1606  for coordinating the operations of the baseband processing circuitry  1308   a . 
     In some embodiments (e.g., when analog baseband signals are exchanged between the baseband processing circuitry  1308   a - b  and the radio IC circuitry  1306   a - b ), the baseband processing circuitry  1308   a  may include ADC  1610  to convert analog baseband signals  1609  received from the radio IC circuitry  1306   a - b  to digital baseband signals for processing by the RX BBP  1602 . In these embodiments, the baseband processing circuitry  1308   a  may also include DAC  1612  to convert digital baseband signals from the TX BBP  1604  to analog baseband signals  1611 . 
     In some embodiments that communicate OFDM signals or OFDMA signals, such as through baseband processor  1308   a , the transmit baseband processor  1604  may be configured to generate OFDM or OFDMA signals as appropriate for transmission by performing an inverse fast Fourier transform (IFFT). The receive baseband processor  1602  may be configured to process received OFDM signals or OFDMA signals by performing an FFT. In some embodiments, the receive baseband processor  1602  may be configured to detect the presence of an OFDM signal or OFDMA signal by performing an autocorrelation, to detect a preamble, such as a short preamble, and by performing a cross-correlation, to detect a long preamble. The preambles may be part of a predetermined frame structure for Wi-Fi communication. 
     Referring back to  FIG.  1 D , in some embodiments, the antennas  1301  ( FIG.  1 D ) may each comprise one or more directional or omnidirectional antennas, including, for example, dipole antennas, monopole antennas, patch antennas, loop antennas, microstrip antennas or other types of antennas suitable for transmission of RF signals. In some multiple-input multiple-output (MIMO) embodiments, the antennas may be effectively separated to take advantage of spatial diversity and the different channel characteristics that may result. Antennas  1301  may each include a set of phased-array antennas, although embodiments are not so limited. 
     Although the radio architecture  1300  is illustrated as having several separate functional elements, one or more of the functional elements may be combined and may be implemented by combinations of software-configured elements, such as processing elements including digital signal processors (DSPs), and/or other hardware elements. For example, some elements may comprise one or more microprocessors, DSPs, field-programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), radio-frequency integrated circuits (RFICs) and combinations of various hardware and logic circuitry for performing at least the functions described herein. In some embodiments, the functional elements may refer to one or more processes operating on one or more processing elements. 
     Some embodiments may be used in conjunction with one or more types of wireless communication signals and/or systems following one or more wireless communication protocols, for example, radio frequency (RF), infrared (IR), frequency-division multiplexing (FDM), orthogonal FDM (OFDM), time-division multiplexing (TDM), time-division multiple access (TDMA), extended TDMA (E-TDMA), general packet radio service (GPRS), extended GPRS, code-division multiple access (CDMA), wideband CDMA (WCDMA), CDMA 2000, single-carrier CDMA, multi-carrier CDMA, multi-carrier modulation (MDM), discrete multi-tone (DMT), Bluetooth®, global positioning system (GPS), Wi-Fi, Wi-Max, ZigBee, ultra-wideband (UWB), global system for mobile communications (GSM), 2G, 2.5G, 3G, 3.5G, 4G, fifth generation (5G) mobile networks, 6 th  generation mobile networks, 3GPP, long term evolution (LTE), LTE advanced, enhanced data rates for GSM Evolution (EDGE), or the like. Other embodiments may be used in various other devices, systems, and/or networks. 
       FIGS.  2 A- 2 C  illustrate embodiments of channels and subchannels (or resource units) that can facilitate multiple transmissions simultaneously such as a EHT PPDU.  FIG.  2 A  illustrates an embodiment of transmissions  2010  between four stations and an AP on four different subchannels (or resource units) of a channel via OFDMA. Grouping subcarriers into groups of resource units is referred to as subchannelization. Subchannelization defines subchannels that can be allocated to stations depending on their channel conditions and service requirements. An OFDMA system may also allocate different transmit powers to different subchannels. 
     In the present embodiment, the OFDMA STA1, OFDMA STA2, OFDMA STA3, and OFDMA STA4 may represent transmissions on a four different subchannels of the channel. For instance, transmissions  2010  may represent an 80 MHz channel with four 20 MHz bandwidth PPDUs using frequency division multiple access (FDMA). Such embodiments may include, e.g., 1 PPDU per 20 MHz bandwidth, 2 PPDU in a 40 MHz bandwidth, and 4 PPDUs in an 80 MHz bandwidth. As a comparison,  FIG.  2 B  illustrates an embodiment of an orthogonal frequency division multiplexing (OFDM) transmission  2015  for the same channel as  FIG.  2 A . The OFDM transmission  2015  may use the entire channel bandwidth. 
       FIG.  2 C  illustrates an embodiment of a 20-Megahertz (MHz) bandwidth  2020  on a channel that illustrates different resource unit (RU) configurations  2022 ,  2024 ,  2026 , and  2028 . In OFDMA, for instance, an OFDM symbol is constructed of subcarriers, the number of which is a function of the physical layer protocol data unit (PPDU) (also referred to as the PHY frame) bandwidth. There are several subcarrier types: 1) Data subcarriers which are used for data transmission; 2) Pilot subcarriers which are utilized for phase information and parameter tracking; and 3) unused subcarriers which are not used for data/pilot transmission. The unused subcarriers are the direct current (DC) subcarrier, the Guard band subcarriers at the band edges, and the Null subcarriers. 
     The RU configuration  2022  illustrates an embodiment of nine RUs that each include 26 tones (or subcarriers) for data transmission including the two sets of 13 tones on either side of the DC. The RU configuration  2024  illustrates the same bandwidth divided into 5 RUs including four RUs with 52 tones and one RU with 26 tones about the DC for data transmission. The RU configuration  2026  illustrates the same bandwidth divided into 3 RUs including two RUs with 106 tones and one RU with 26 tones about the DC for data transmission. And the RU configuration  2028  illustrates the same bandwidth divided into 2 RUs including two RUs with 242 tones about the DC for data transmission. Embodiments may be capable of additional or alternative bandwidths such as such as 40 MHz, 80 MHz, 160 MHz, 240 MHz, and 320 MHz. 
     Many embodiments support RUs of 26-tone RU, 52-tone RU, 106-tone RU, 242-tone RU, 484-tone RU, 996-tone RU, 2x996-tone RU, and 4x996-tone RU. In some embodiments, RUs that are the same size or larger than 242-tone RUs are defined as large size RUs and RUs that are smaller than 242-tones RUs are defined as small size RUs. In some embodiments, small size RUs can only be combined with small size RUs to form small size MRUs. In some embodiments, large size RUs can only be combined with large size RUs to form large size MRUs. 
       FIG.  2 D  illustrates an embodiment of a HE MU PPDU  2100  in the form of an 802.11, orthogonal frequency division multiple access (OFDMA) packet on a 20 MHz channel of, e.g., a 2.4 GHz link, a 5 GHz link, a 6 GHz link, or any other frequency. In some embodiments, the baseband processing circuitry, such as the baseband processing circuitry  1218  in  FIG.  1 C , may transmit a HE MU PPDU  2100  transmission on the 6 GHz carrier frequency, optionally with beamforming. In some embodiments, the HE MU PPDU  2100  may comprise a MAC association request or response frame, an MAC reassociation request or response frame, a MAC authentication frame, and/or the like. 
     The HE MU PPDU  2100  may comprise a legacy preamble  2110  to notify other devices in the vicinity of the source STA, such as an AP STA, that the 20 MHz channel is in use for a duration included in the legacy preamble  2110 . The legacy preamble  2110  may comprise one or more short training fields (L-STFs), one or more long training fields (L-LTFs), and one or more signal fields (L-SIG and RL-SIG). 
     The HE MU PPDU  2100  may also comprise a HE preamble  2120  to identify a subsequent 6 GHz carrier link transmission as well as the STAs that are the targets of the transmission. Similarly, the HE preamble  2120  may comprise one or more short training fields (HE-STFs), one or more long training fields (HE-LTFs), and one or more signal fields (HE-SIG). 
     After the HE preamble  2120 , the HE MU PPDU  2100  may comprise a data portion  2140  that includes a single user (SU) or multiple user (MU) packet.  FIG.  2 D  illustrates the MU packet with four designated RUs. Note that the number and size of the RUs may vary between packets based on the number of target STAs and the types of payloads in the data portions  2140 . 
       FIG.  2 E  depicts another embodiment of the MAC Management frame in the HE MU PPDU  2200 . In some embodiments, the HE MU PPDU  2200  may be a frame format used for a DL transmission to one or more STAs. In the HE MU PPDU  2200 , the MAC management frame may comprise two legacy (L) short training fields (STFs) with an 8 microseconds duration each, a legacy (L) signal (SIG) field with a four-microsecond duration, a repeated, legacy signal field (RL-SIG) with a 4-microsecond duration, and a U-SIG with 2 symbols having a 4 microsecond duration each. The HE MU PPDU  2200  format may also comprise a HE signal field (HE-SIG) with 2 symbols at 4 microseconds each, an HE STF, a number of HE-LTFs, a data field, and a packet extension (PE) field. In some embodiments, the data field may comprise may be a MAC management frame. 
     As illustrated in  FIG.  2 F , the data field of the HE MU PPDU  2200  may comprise a MAC management frame  2210  such as a MAC association request or response frame, an MAC reassociation request or response frame, a MAC TID-to-Link mapping request/response frame, a disassociation frame, and/or the like. The data field may comprise an MPDU (PSDU) such as a MAC (re)association request frame, (re)association response frame, disassociation frame, or a TID-to-Link mapping request or response frame comprising a recipient MAC address or recipient ID field in the MAC header (frame header) to identify a non-collocated AP MLD as a recipient of the MAC reassociation request frame, disassociation frame, or a TID-to-Link mapping request or response frame. The MAC authentication frame may not include the recipient MAC address or recipient ID field in the MAC header. 
     In some embodiments, the MAC association request and response frames and/or reassociation request and response frames may comprise an add links field to include a value of a flag to indicate that the association request frames and/or reassociation request frames request frame requests a setup or addition of links and does not request changing current links associated with the non-AP MLD that transmits the association request frames and/or reassociation request frames. The add links field may reside in a subfield of the frame control field of the frame header, a field of the frame header, or a field of the frame body. For example, the add links field may include one bit set to a logical value of one to indicate that the request only adds links and does not change current links. The add links field may include one bit set to a logical value of zero to indicate that the request is not an adds links only request. The add links field may reside in the association response frames and/or reassociation response frames to indicate that the response frame is responsive to a request to add links only (e.g., logical 1) or is not responsive to an add links only request (e.g., logical 0). In other embodiments, the flag value is a logical 0 to indicate that the response frame is responsive to a request to add links only or a logical 1 to indicate that the response frame is not responsive to an add links only request. 
     In some embodiments, the MAC association request and response frames, reassociation request and response frames, and/or disassociation frames, may comprise a remove links field to include a value of a flag to indicate that the association request frames, reassociation request frames and/or disassociation frames, request a removal or deletion of links and does not request changing other current links associated with the non-AP MLD that transmits the association request frames and/or reassociation request frames. The remove links field may reside in a subfield of the frame control field of the frame header, a field of the frame header, or a field of the frame body. For example, the remove links field may include one bit set to a logical value of one to indicate that the request only remove links identified and does not change other current links. The remove links field may include one bit set to a logical value of zero to indicate that the request is not a remove links only request. The remove links field may reside in the association response frames, reassociation response frames, and/or disassociation frames to indicate that the response frame is responsive to a request to remove links only (e.g., logical 1) or is not responsive to a remove links only request (e.g., logical 0). In other embodiments, the flag value is a logical 0 to indicate that the response frame is responsive to a request to remove links only or a logical 1 to indicate that the response frame is not responsive to a remove links only request. 
     The MAC reassociation request frame or a TID-to-Link mapping request or response frame may include a 2 octet frame control field, a 2 octet duration field, a 6 octet address 1 field, a 6 octet address 2 field, a 6 octet address 3 field, a 2 octet sequence control field, a 0 or 4 octet high-throughput (HT) control field, and the recipient MAC address or recipient ID field in the MAC header. MAC association request frame or a TID-to-Link mapping request or response frame may also include a variable length frame body field, and a 4 octet frame check sequence field comprising a value, such as a 32-bit cyclic redundancy code (CRC), to check the validity of and/or correct preceding frame. 
     The Duration field may be the time, in microseconds, required to transmit the pending management frame, plus, in some embodiments, one acknowledgement (ack) frame and one or more short interframe spaces (SIFSs). If the calculated duration includes a fractional microsecond, that value may be rounded up to the next higher integer. 
     The address 1 field of the MAC association request frame or a TID-to-Link mapping request or response frame may comprise the address of the intended receiver such as an AP STA of an AP MLD of a non-collocated AP MLD. The address 2 field may be the address the transmitter such as a non-AP MLD that transmitted the MAC association request frame or a TID-to-Link mapping request or response frame. The address 3 field may be the basic service set identifier (BSSID) of the AP MLD of the non-collocated AP MLD. 
     The HT control field may be present in management frames as determined by the +HTC subfield of the frame control field. 
     The recipient MAC address or recipient ID field may include a MAC address associated with the non-collocated AP MLD, a MLD ID associated with the non-collocated AP MLD, or a flag such as one or more bits to identify the non-collocated AP MLD as a recipient of the MAC association request frame or a TID-to-Link mapping request or response frame. 
     The frame body may include one or more fields and/or elements such as the fields and/or elements depicted in  FIGS.  2 G- 2 M . The frame check sequence (FCS) field may include a sequence of bits such as a 32-bit cyclic redundancy check (CRC). 
       FIG.  2 G  depicts an embodiment of a frame body  2232  of an association request frame or reassociation request frame such as the management frame  2210  shown in  FIG.  2 F . The frame body  2232  format may include one or more other fields and/or elements along with a ML element, an extremely high throughput (EHT) capabilities element, and a TID-to-link mapping element. The ML element may comprise fields as shown in the ML element  2238  depicted in  FIG.  2 J . 
     The EHT capabilities element may comprise a number of fields that are used to advertise the EHT capabilities of an EHT STA. The EHT capabilities element may comprise an element ID field, a length field, an element ID Extension field, an EHT MAC capabilities information field, an EHT PHY capabilities information field, a Supported EHT-MCS And NSS Set field, and an EHT PPE Thresholds field. 
     The TID-to-link mapping field may comprise one or two TID-To-Link Mapping elements if a non-AP STA affiliated with a non-AP MLD initiates both an association with an AP MLD and a TID-to-link mapping negotiation. 
       FIG.  2 H  depicts an embodiment of a frame body  2234  of an association response frame or reassociation response frame such as the management frame  2210  shown in  FIG.  2 F . The frame body  2234  format may include one or more other fields and/or elements along with a target wake time (TWT) element, a ML element, an extremely high throughput (EHT) capabilities element, an EHT operation element, and a TID-to-link mapping element. The TWT element may comprise a target wake time field that contains a positive integer corresponding to a TSF time at which the STA requests to wake, or 0 when the TWT setup command subfield contains the value corresponding to the command “Request TWT”. When a TWT responding STA with GroupingSupport equal to 0 transmits a TWT element to the TWT requesting STA, the TWT element contains a value in the target wake time field corresponding to a TSF time at which the TWT responding STA requests the TWT requesting STA to wake and it does not contain the TWT group assignment field. 
     The ML element may comprise fields as shown in the ML element  2238  depicted in  FIG.  2 J . The EHT capabilities element may comprise a number of fields that are used to advertise the EHT capabilities of an EHT STA. The EHT capabilities element may comprise an Element ID field, a Length field, an Element ID Extension field, an EHT MAC Capabilities Information field, an EHT PHY Capabilities Information field, a Supported EHT-MCS And NSS Set field, and an EHT PPE thresholds field. 
     The EHT operation element may comprise an EHT operation parameters field, a disabled subchannel bitmap field, an EHT default PE duration field, a group addressed buffered unit (BU) indication limit field, a group address BU indication exponent field, and a reserved field. The EHT operation information present subfield is set to 1 if the EHT operation information field is present and set to 0 otherwise. 
     The TID-to-link mapping field may comprise one or two TID-To-Link Mapping elements if a non-AP STA affiliated with a non-AP MLD initiates both an association with an AP MLD and a TID-to-link mapping negotiation. 
       FIG.  2 I  depicts an embodiment of a frame body  2236  of an TID-to-Link mapping request/response frame such as the management frame  2210  shown in FIG. F. The frame body  2236  format may include a category field, a protected EHT action field, a status code field (in the TID-to-Link mapping response frame), and a TID-to-Link mapping element. 
     The category field may include a value such as 37 to indicate that the TID-to-Link mapping request and response frames are protected EHT frames. The Protected EHT Action field may include a value such as zero to indicate that the frame is a TID-to-Link mapping request frame or a value such as one to indicate that the frame is a TID-to-Link mapping response frame. 
     For a TID-to-Link mapping request frame, the Dialog Token field is a set to a nonzero value chosen by the STA sending the TID-To-Link Mapping Request frame to identify the request/response transaction. For a TID-to-Link mapping response frame, when the TID-To-Link Mapping Response frame is transmitted as a response to a TID-To-Link Mapping Request frame, the Dialog Token field is the value in the corresponding TID-To-Link Mapping Request frame. When the TID-To-Link Mapping Response frame is transmitted as an unsolicited response, then the Dialog token is set to 0. 
     For a TID-to-Link mapping request frame, the TID-To-Link Mapping field contains one or two TID-To-Link Mapping elements. When it contains two TID-To-Link Mapping elements, the Direction subfield in one of the TID-To-Link Mapping elements is set to 0 and the Direction subfield in the other of the TID-To-Link Mapping elements is set to 1. 
     During the link enablement/disablement phase, the non-AP MLD may transmit a TID-to-Link mapping request frame to enable new links between a non-AP MLD and a second AP MLD and disable old links between the non-AP MLD and the first AP MLD by negotiation of the TID-to-link mapping. New links may be enabled by mapping TIDs to the link IDs of the links and old links may be disabled by mapping no (zero) TIDs to the old links. 
     In some embodiments, the TID-to-Link mapping request frame may enable links between the non-AP STAs of the non-AP MLD by inclusion of a link mapping for one or more TIDs 0 through n in the TID-to-Link mapping element shown in  FIG.  2 O  that maps the one or more TIDs to the new link IDs added for the second AP MLD during the new link phase. In such embodiments, a bitmap of the links for the second AP MLD to which the TIDs are mapped are enabled after a successful negotiation and the first AP MLD may transmit a TID-to-Link mapping response frame with a status code indicative of the successful negotiation. 
     In some embodiments, the bitmap of the links may only associate the new link IDs for links between the non-AP MLD and the second AP MLD in the bitmaps of links for the TIDs in the TID-to-Link mapping element(s) of TID-to-Link mapping request frame to enable the link IDs for the second AP MLD and disable the link IDs for the links between the non-AP MLD and the first AP MLD. In such embodiments, transition logic circuitry of the first AP MLD and/or the second AP MLD may transmit a TID-to-Link mapping response frame to the non-AP MLD with the status code set to a value to indicate successful negation of the new link mapping of the TIDs. 
     In some embodiments, the non-AP MLD may transmit a TID-to-Link mapping request to the first AP MLD to negotiate the TID mapping with a bitmap of links for each TID that includes both the link IDs for the old links and link IDs for the new links for one or more of the TIDs. After receipt of a TID-to-Link mapping response frame indicating of a successful negotiation, the non-AP MLD may transmit a TID-to-Link mapping request frame that only includes the new link IDs for the links between the non-AP MLD and the second AP MLD to disable the old link IDs for the links between the non-AP MLD and the first AP MLD. 
     After one or more frame exchanges of the TID-to-Link mapping request/response frames, all the links between the non-AP MLD and the first AP MLD are disabled and al the links between the non-AP MLD and the second AP MLD are enabled. 
     For a TID-to-Link mapping response frame, the TID-To-Link Mapping field may contain zero, one, or two TID-To-Link Mapping elements in order to suggest a preferred mapping. The TID-To-Link Mapping field may contain one or two TID-To-Link Mapping elements if the Status Code is set to 134 (PREFERRED_TID_TO_LINK_MAP PING_SUGGESTED). Otherwise, the TID-To-Link Mapping field may not contain a TID-To-Link Mapping element. When it contains two TID-To-Link Mapping elements, the Direction subfield in one of the TID-To-Link Mapping elements is set to 0 (Downlink) and the Direction subfield in the other of the TID-To-Link Mapping elements is set to 1 (Uplink). 
     The TID-to-Link mapping element may comprise fields as shown in the TID-to-Link mapping element  2247  depicted in  FIG.  2 O . 
       FIG.  2 J  depicts an embodiment of a multi-link (ML) element  2238  of an association frame, a reassociation frame, and an authentication frame such as the management frame  2210  shown in  FIG.  2 F . The ML element  2238  format may include an element ID field, a length field, an element ID extension field, a ML control field, a common info field, and a link info field. Depending on the variant (indicated by the Type subfield) of this element, particular field(s) or subfield(s) within a field can be absent. The Element ID, Length, and Element ID Extension fields may identify the format of the element, the length of the element, and identify element extensions. 
     The ML control field may identify the type of or variant of the ML element and may comprise a presence bitmap. The presence bitmap subfield is used to indicate the presence of various subfields in the common info field and has different format for different variants of the ML element. 
     The common info field carries information that is common to all the links except for link ID Info subfield and BSS parameters change count subfield that are for the link on which the ML element is sent. The common info field is depicted in  FIG.  2 K . 
     The link info field carries information specific to the links and is optionally present. When the link info field is present, it contains one or more subelements such as the per-STA profile subelements. 
       FIG.  2 K  depicts an embodiment of a common info field  2240  of an association frame or a reassociation frame, such as the management frame  2210  shown in  FIG.  2 F . The common info field carries information that is common to all the links except for Link ID Info subfield and BSS parameters change count subfield that are for the link on which the ML element is sent. The common info field  2240  may include a common info length field, an MLD MAC address field, a link ID info field, a BSS parameters change count field, a medium synchronization delay information field, an enhanced ML (EML) capabilities field, an MLD capabilities and operations field, and an AP MLD ID field. 
     The common info length subfield indicates the number of octets in the common info field, including one octet for the common info length subfield. The MLD MAC Address subfield specifies the MAC Address of the MLD with which the STA transmitting the basic ML element is affiliated. 
     In some embodiments, the link ID info subfield of the common info field is included in the (re)association request frame transmitted by the non-AP MLD to the collocated AP MLD of the non-collocated to add a new recipient MAC address or recipient ID field in the link ID info subfield. The new recipient MAC address or recipient ID field may include the MAC address of the non-collocated AP MLD or a MLD ID for the non-collocated AP MLD to address the (re)association request frame to the non-collocated AP MLD affiliated with the AP MLD that receives the (re)association request frame. In some embodiments, the link ID field is also included in the link ID info field and may include the value of the link ID of an AP STA of the collocated AP MLD that receives the (re)association request frame. In other embodiments, the link ID field is not present in the link ID info subfield. 
     In other embodiments, the recipient MAC address or recipient ID field may be included in the frame header (or MAC header) of the (re)association request frame as shown in the management frame in  FIG.  2 F . In such embodiments, the link ID info field of the may not be present in the common info field if the basic ML element is sent by a non-AP STA. 
     In some embodiments, the recipient MAC address or recipient ID field may comprise a value of a flag such as one or more bits to identify a recipient of the (re)association request frame as the collocated AP MLD that receives the (re)association request frame or to identify the recipient of the (re)association request frame as the non-collocated AP MLD affiliated with the collocated AP MLD that receives the (re)association request frame via a RA in an address field for the frame header. 
     The BSS parameters change count subfield in the common info field carries an unsigned integer, initialized to 0. The value carried in the subfield is incremented by 1 when a critical update and occurs to the operational parameters for the AP STA that is affiliated with an AP MLD which is described in the basic ML element. 
     In some embodiments, the link ID Info subfield and the BSS parameters change count subfield are present in the common info field of the basic ML element, when the element is carried in a management frame transmitted by an AP, except for an authentication frame. In some embodiments, the medium synchronization delay information subfield in the common info subfield is not present if the basic ML element is sent by a non-AP STA. When the basic ML element is included in a frame sent by an AP STA, the condition for the presence of the medium synchronization delay information subfield in the common info field is defined by a medium access recovery procedure. 
     The EML capabilities subfield contains a number of subfields that are used to advertise the capabilities for enhanced ML single radio (EMLSR) operation and enhanced ML multi-radio (EMLMR) operation. The MLD capabilities and operations subfield may be present in the common info field of the basic ML element carried in a beacon, probe response, (re)association request, and (re)association response frames. 
     The AP MLD ID subfield indicates the identifier of the AP MLD whose MLD information is carried in the basic ML element. In some embodiments, the AP MLD ID subfield is not present in the basic ML element included in a frame sent by a non-AP STA affiliated with a non-AP MLD. In some embodiments, the AP MLD ID subfield is not present in the basic ML element when the element is carried in a beacon, (re)association response, authentication, or probe response frame that is not a ML probe response. 
       FIG.  2 L  depicts an embodiment of a link ID info subfield  2242  of a common info field  2240  shown in  FIG.  2 K  of an association request frame or a reassociation request frame such as the management frame  2210  shown in  FIG.  2 F . In some embodiments, the link ID info subfield of the common info field is included in the (re)association request frame transmitted by the non-AP MLD to the collocated AP MLD of the non-collocated to add a new recipient MAC address or recipient ID field in the link info ID subfield. In other embodiments, the link ID info subfield comprise the new recipient MAC address or recipient ID field to address the association request frame to the non-collocated AP MLD rather than to the AP MLD (affiliated with the non-collocated AP MLD) at which the association request frame is received in accordance with address 1 in the frame header of the association request frame. In other embodiment, the new recipient MAC address or recipient ID field resides in the frame header as a field in the frame header or a subfield of a frame control field in the frame header. 
     The new recipient MAC address or recipient ID field may include a MAC address, MLD ID, or a flag indicative of the non-collocated AP MLD affiliated with the collocated AP MLD that is identified as a recipient of the (re)association request frame. 
       FIG.  2 M  depicts an embodiment of a link info subfield  2244  of a ML element  2238  shown in  FIG.  2 J  of an association request frame, association response frame, a reassociation request frame, a reassociation response frame, and a disassociation frame, such as the management frame  2210  shown in FIG. F. The link info field may comprise one or more subelements. In the present embodiment, the link info field comprises a frame format for a per-STA profile subelement appended with “other subelements” such as additional per-STA profile subelements. The per-STA profile subelement may comprise a subelement ID that may carry a value of zero to indicate the subelement is a per-STA subelement. The length field may comprise a value indicative of the length of the subelement including the STA control field, the variable length STA info field, and the variable length STA profile field. 
     The STA control field may comprise a complete profile field to include the complete profile of a STA associated with the per-STA profile subelement, a STA MAC address present field, other fields, and a reserved field. The STA MAC address present field may indicate whether or not a STA MAC address field is included in the STA info field. The STA info field may comprise one or more fields including a STA MAC address field and the STA MAC address field may comprise a MAC address for the STA that is described in the per-STA profile subelement such as a MAC address for an AP STA of a second AP MLD affiliated with a non-collocated AP MLD. 
     In many embodiments, the non-AP MLD may request to setup or add links to a non-collocated AP MLD and the association request frame or reassociation request frame may include a flag in a field (such as the ADD LINKS field shown in  FIG.  2 F ) in the frame header, in the frame control field of the frame header, or in the frame body of the association request frame or reassociation request frame. The flag may be set to, e.g., a logical one to indicate that the association request frame or reassociation request frame is a request to only add new links and does not request to change current links associated with non-AP STAs of the non-AP MLD. In such embodiments, the flag may be set to, e.g., a logical zero to indicate that the association request frame or reassociation request frame does not request to only add new links. 
     In some embodiments, the link info subfield  2244  of the ML element is included in the association request frame, reassociation request frame, or disassociation frame transmitted by a non-AP MLD to a first collocated AP-MLD affiliated with a non-collocated AP MLD. In many embodiments, the link info field may comprise a per-STA profile subelement for each non-AP STA for which the non-AP MLD may request to add a new link to an AP STA of the second AP MLD (except, the non-AP STA for which the complete profile is included in the ML element) for an add link phase of transitioning from the first AP MLD to the second AP MLD. In many embodiments, the link info field may comprise a per-STA profile subelement for each non-AP STA for which the non-AP MLD may request to delete or remove an old link (or current link) from an AP STA of the first AP MLD for a link removal phase of transitioning from the first AP MLD to the second AP MLD. In other embodiments, the link info field may not include per-STA subelements for non-AP STAs of the non-AP MLD. 
     In many embodiments, the non-AP MLD may request to setup or add links to a non-collocated AP MLD and the association request frame, reassociation request frame, or disassociation frame may include a flag in a field (such as the REMOVE LINKS field shown in  FIG.  2 F ) in the frame header, in the frame control field of the frame header, or in the frame body of the association request frame, reassociation request frame, or disassociation frame. The flag may be set to, e.g., a logical one to indicate that the association request frame, reassociation request frame, or disassociation frame is a request to only remove old links identified and does not request to change other current links associated with non-AP STAs of the non-AP MLD. In such embodiments, the flag may be set to, e.g., a logical zero to indicate that the association request frame, reassociation request frame, or disassociation frame does not request to only remove old links. 
     The association request frame or reassociation request frame may also comprise a recipient addr or recipient ID field in the frame header, in a subfield of the frame control field of the frame header, or in the frame body to identify the non-collocated AP MLD with a MAC address of the non-collocated AP MLD, a MLD ID of the non-collocated AP MLD, or a flag to identify the non-collocated AP MLD. 
     The association request frame or reassociation request frame may also include a per-STA profile subelement in the link info field  2244  for each link to add to identify the AP STAs of the non-collocated AP MLD with which to add the link. For example, if the non-AP MLD is transitioning from the first AP MLD affiliated non-collocated AP MLD to the second AP MLD affiliated non-collocated AP MLD, the non-AP MLD may transmit an association request frame or a reassociation request frame to the first AP MLD of the non-collocated AP MLD. In some embodiments, the link info field  2244  may include five per-STA subelements. Two of the per-STA subelements may include the complete profiles, link IDs, and STA MAC addresses to describe non-AP STA 2 and non-AP STA 3 (where the ML element comprises the complete profile of the non-AP STA 1). The other three per-STA subelements may include at least the link IDs and STA MAC addresses for three AP STAs of the second AP MLD. In some embodiments, the other three per-STA subelements for the AP STAs may also include the complete profiles for the AP STAs at least to the extent that the non-AP MLD obtained through a discovery protocol. In some embodiments, the association request frame or reassociation request frame may only include three per-STA subelements and the three per-STA subelements may include at least the link IDs and STA MAC addresses for three AP STAs of the second AP MLD. 
     Note that while many examples herein may describe three links, three non-AP STAs, and three AP MLD STAs, and reference transitioning three links, the non-AP MLDs and the AP MLDs are not limited to three STAs and are not limited to adding or transitioning links for the all the STAs. The number of STAs may be two STAs, three STAs, four or more STAs, and/or the like and the number of links that the non-AP MLD adds may not be the same as the number of STAs in the non-AP MLD or in the AP MLD. Furthermore, the non-AP MLD may transition from links with a first AP MLD to links associated with a second AP MLD, a third AP MLD, or more AP MLDs or may transition from links with two or more AP MLDs to links with one or more AP MLDs. 
     In some embodiments, the link info subfield  2244  of the ML element is included in the association response frame or reassociation response frame transmitted by the first AP-MLD to the non-AP MLD in response to an association request frame received from a non-AP MLD to add links to the second AP MLD affiliated with a non-collocated AP MLD. In many embodiments, the association response frame or reassociation response frame may also include a flag, which may comprise a bit or more than one bit in a subfield of the frame control field in the frame header, in another field of the frame header, or in the frame body. The flag may be set to, e.g., a logical one to indicate that the association response frame or reassociation response frame is responsive to a request to only add new links and does not request to change current links associated with non-AP STAs of the non-AP MLD. In such embodiments, the flag may be set to, e.g., a logical zero to indicate that the association response frame or reassociation response frame is responsive to an association request frame or reassociation request frame that does not request to only add new links. 
     In some embodiments, for the association response frame or the reassociation response frame, the STA control field of each per-STA profile subelement of the link info field of the ML element may include a new non-collocated link ID field to include a value for a new link ID generated for a link between a non-AP STA and an AP STA of the second AP MLD that is affiliated with a non-collocated AP MLD. For instance, a first AP MLD may receive an association request frame from the non-AP MLD that requests addition of links between three non-AP STAs of the non-AP MLD and three AP STAs of the second AP MLD where the first AP MLD and the second AP MLD are affiliated with the non-collocated AP MLD. The first AP MLD may generate the new link ID for each link and include the value of the new link ID in the non-collocated link ID field of each per-STA profile subelement for the three AP STAs of the second AP MLD. 
     In some embodiments, in addition to inclusion of the new link IDs in the non-collocated link ID fields of the per-STA profile subelements, the first AP MLD may create a mapping table entry for a mapping table for each of the new link IDs such as the mapping table  2246  shown in  FIG.  2 N . 
       FIG.  2 N  depicts an embodiment of a mapping table  2246  maintained by transition logic circuitry of a first AP MLD in response to generation of a new link ID that identifies a link between a non-AP STA and an AP STA of a second AP MLD, where the first AP MLD and the second AP MLD are affiliated with a non-collocated AP MLD. For instance, the first AP MLD may generate the new link ID in response to receipt of an association request frame received from the non-AP MLD that identifies the non-collocated AP MLD as the recipient of the reassociation request frame and identifies a request for a link setup between the non-AP STA and an AP STA of the second AP MLD during a new link phase of the transition of links of the non-AP MLD from the first AP MLD to the second AP MLD. 
     During the new link phase, the first AP MLD may generate entries with link IDs for each of the new links added to the mapping table  2246 . During the link enablement/disablement phase of the transition, the non-AP MLD may transmit a TID-to-Link request frame to enable the new links based on identification of the new link IDs in a non-collocated link ID field of the TID-to-Link request frame. In some embodiments, the old link IDs for the links between the non-AP MLD and the first AP MLD may be disabled in response to the same TID-to-Link request frame or in response to additional TID-to-Link request frames. 
     An entry of the mapping table  2246  may include two fields, a collocated AP MLD field and a non-collocated AP MLD field. The collocated AP MLD field may include a link ID field and an AP MLD MAC address or MLD ID field. The link ID field may include the value of link ID for the link between the non-AP STA and the AP STA of the second AP MLD. The AP MLD MAC address or MLD ID field may comprise a value for the MAC address or MLD ID of the second AP MLD. 
     In the same entry of the mapping table  2246 , the non-collocated AP MLD field may comprise a link ID field to associate the content of the link ID field of the non-collocated AP MLD field with the content of the collocated AP MLD field. The link ID field of the non-collocated AP MLD field may comprise a value of the new link ID created by the first AP MLD to represent the link between the non-AP STA and the AP STA of the second AP MLD. In some embodiments, the non-collocated AP MLD field may comprise other fields such as a MAC address or MLD ID that may include a value for, e.g., a MAC address or MLD ID for the second AP MLD. 
       FIG.  2 O  depicts an embodiment of a TID-to-Link mapping element  2247  of an (re)association request frame, a (re)association response frame, a TID-to-Link mapping request frame, or a TID-to-Link mapping response frame such as the frames shown in  FIGS.  2 F- 2 I . The TID-To-Link Mapping element indicates links on which frames belonging to each TID can be exchanged. In many embodiments, during the link enablement/disablement phase, the non-AP MLD may transmit a TID-to-Link mapping request frame with the TID-To-Link Mapping element  2247  to enable a link ID generated by a first collocated AP MLD (or first AP MLD) to represent a link between a non-AP STA of a non-AP MLD and an AP STA of a second AP MLD and/or to disable a link ID for a link between a non-AP STA of a non-AP MLD and an AP STA of a first AP MLD. 
     The TID-To-Link Mapping element  2247  format may include an element ID field, a length field, an element ID extension field, a TID-to-Link mapping control field, a mapping switch time field, an expected duration field, and one or more optional link mapping of TID 0 through link mapping of TID 7 fields. The Element ID, Length, and Element ID Extension fields may identify the format of the element, the length of the element and identify element extensions. The format of the TID-To-Link Mapping Control field is shown in  FIG.  2 P . 
     The Link Mapping of TID n field (where n= 0, 1, ..., 7) indicates the link(s) on which frames belonging to the TID n are allowed to be sent (i.e., carries a bitmap of the links to which the TID n is mapped to). A value of 1 in bit position i (where i= 0, 1, ..., 14) of the Link Mapping of TID n field indicates that TID n is mapped to the link associated with the link ID i for the direction as specified in the Direction subfield. A value of 0 in bit position i indicates that the TID n is not mapped to the link associated with the link ID i. When the Default Link Mapping subfield is set to 1, this field is not present. 
       FIG.  2 P  depicts an embodiment of a TID-to-Link control field format  2248  of a TID-to-Link mapping element such as the TID-to-Link mapping element  2247  shown in  FIG.  2 O .The TID-to-Link control field format  2248  may comprise a direction field, a default link mapping field, a mapping switch time field, an expected duration present field, a reserved field, and an optional link mapping presence indicator field. The Direction subfield is set to 0 if the TID-to-Link Mapping element provides the TID-to-link mapping information for frames transmitted on the downlink. It is set to 1 if the TID-To-Link Mapping element provides the TID-to-link mapping information for frames transmitted on the uplink. It is set to 2 if the TID-To-Link Mapping element provides the TID-to-link mapping information for frames transmitted both on the downlink and the uplink. The value of 3 is reserved. 
     The Default Link Mapping subfield is set to 1 if the TID-To-Link Mapping element represents the default TID-to-link mapping. Otherwise, it is set to 0. The Mapping Switch Time Present subfield is set to 1 if the Mapping Switch Time field is present and 0 otherwise. The Expected Duration Present subfield is set to 1 if the Expected Duration field is present and 0 otherwise. 
     The Link Mapping Presence Indicator subfield indicates whether the Link Mapping of TID n field is present in the TID-To-Link Mapping element (i.e., it identifies the TID(s) for which the mapping is provided in the element). A value of 1 in bit position n of the Link Mapping Presence Indicator subfield indicates that the Link Mapping of TID n field is present in the TID-To-Link Mapping element. Otherwise, the Link Mapping of TID n field is not present in the TID-To-Link Mapping element. When the Default Link Mapping subfield is set to 1, this subfield is not present. 
     In some embodiments, the reserved field or a portion of the reserved field may be allocated for a non-collocated link ID field. The non-collocated link ID field may comprise a value for a link ID generated by a first collocated AP MLD (or first AP MLD) to represent a link between a non-AP STA of a non-AP MLD and an AP STA of a second AP MLD. The link ID may identify a link of the non-AP MLD with a non-collocated AP MLD affiliated with the first AP MLD and a second AP MLD. Identification of the link of the non-AP MLD with a non-collocated AP MLD in a TID-to-Link mapping request frame transmitted from the non-AP MLD to the first AP MLD may identify a link to enable during the link enablement/disablement phase of the transition of the links of non-AP STAs between the non-AP MLD and the first AP MLD to links between the non-AP STAs between the non-AP MLD and the second AP MLD. In other embodiments, the identification of the link of the non-AP MLD with a non-collocated AP MLD in a TID-to-Link mapping request frame may include a non-collocated link ID field in the frame header of the TID-to-Link mapping request frame as shown in  FIG.  2 F . 
       FIGS.  2 Q-R  illustrates an example of a PPDU  2260  with a MAC management frame that may be transmitted by an MLD STA to an AP MLD. In  FIG.  2 Q , the PPDU  2260  format may be used for a transmission of an association frame, a reassociation frame, or an TID-to-Link mapping frame, either as a request frame or a response frame. 
     The PPDU  2260  format may comprise an OFDM PHY preamble, an OFDM PHY header, a PSDU, tail bits, and pad bits. The PHY header may contain the following fields: length, rate, a reserved bit, an even parity bit, and the service field. in terms of modulation, the length, rate, reserved bit, and parity bit (with 6 zero tail bits appended) may constitute a separate single OFDM symbol, denoted signal, which is transmitted with the combination of BPSK modulation and a coding rate of R = ½ 
     The PSDU (with 6 zero tail bits and pad bits appended), denoted as data, may be transmitted at the data rate described in the rate field and may constitute multiple OFDM symbols. The tail bits in the signal symbol may enable decoding of the rate and length fields immediately after reception of the tail bits. The rate and length fields may be required for decoding the data field of the PPDU. 
     In  FIG.  2 R , the data field of the PPDU may comprise an MPDU such as a MAC management frame  2270 . The MAC management frame  2270  may include a 2 octet frame control field, a 2 octet duration field, a 6 octet RA field, and a 4 octet frame check sequence field comprising a value, such as a 32-bit CRC, to check the validity of and/or correct preceding frame. 
     In several embodiments, the value of the addr1 field of the MAC management frame is set to the recipient address (RA) of the MAC management frame  2270  such as a collocated AP MLD affiliated with a non-collocated AP MLD. 
       FIG.  3    depicts an embodiment of an apparatus to generate, transmit, receive, and interpret or decode PHY frames and MAC frames. The apparatus comprises a transceiver  3000  coupled with baseband processing circuitry  3001 . The baseband processing circuitry  3001  may comprise a MAC logic circuitry  3091  and PHY logic circuitry  3092  as well as transition logic circuitry  3093 . In other embodiments, the baseband processing circuitry  3001  may be included on the transceiver  3000 . 
     The MAC logic circuitry  3091  and PHY logic circuitry  3092  may comprise code executing on processing circuitry of a baseband processing circuitry  3001 ; circuitry to implement operations of functionality of the MAC or PHY; or a combination of both. In the present embodiment, the MAC logic circuitry  3091  and PHY logic circuitry  3092  may comprise transition logic circuitry  3093  to transition links of a non-AP MLD from a first collocated AP MLD affiliated with a non-collocated AP MLD to a second collocated AP MLD affiliated with the non-collocated AP MLD. For example, the transition logic circuitry of the non-AP MLD may implement transition logic circuitry to prepare for the link transition for one or more STAs of the non-AP MLD, add new links between the one or more STAs of the non-AP MLD and one or more AP STAs of the second AP collocated MLD, enablement of the links between the one or more STAs of the non-AP MLD and one or more AP STAs of the second AP collocated MLD, disablement of the links between the one or more STAs of the non-AP MLD and one or more AP STAs of the first AP collocated MLD, and link removal of the links between the one or more STAs of the non-AP MLD and one or more AP STAs of the first AP collocated MLD. 
     The MAC logic circuitry  3091  may determine a frame such as a MAC management frame and the PHY logic circuitry  3092  may determine the physical layer protocol data unit (PPDU) by prepending the frame, also called a MAC protocol data unit (MPDU), with a physical layer (PHY) preamble for transmission of the MAC management frame via the antenna array  3018 . The PHY logic circuitry  3092  may cause transmission of the MAC management frame in the PPDU. 
     The transceiver  3000  comprises a receiver  3004  and a transmitter  3006 . Embodiments have many different combinations of modules to process data because the configurations are deployment specific.  FIG.  3    illustrates some of the modules that are common to many embodiments. In some embodiments, one or more of the modules may be implemented in circuitry separate from the baseband processing circuitry  3001 . In some embodiments, the baseband processing circuitry  3001  may execute code in processing circuitry of the baseband processing circuitry  3001  to implement one or more of the modules. 
     In the present embodiment, the transceiver  3000  also includes WUR circuitry  3110  and  3120 . The WUR circuitry  3110  may comprise circuitry to use portions of the transmitter  3006  (a transmitter of the wireless communications I/F such as wireless communications I/Fs  1216  and  1246  of  FIG.  1 C ) to generate a WUR packet. For instance, the WUR circuitry  3110  may generate, e.g., an OOK signal with OFDM symbols to generate a WUR packet for transmission via the antenna array  3018 . In other embodiments, the WUR may comprise an independent circuitry that does not use portions of the transmitter  3006 . 
     Note that a MLD such as the AP MLD  1210  in  FIG.  1 C  may comprise multiple transmitters to facilitate concurrent transmissions on multiple contiguous and/or non-contiguous carrier frequencies. 
     The transmitter  3006  may comprise one or more of or all the modules including an encoder  3008 , a stream deparser  3066 , a frequency segment parser  3007 , an interleaver  3009 , a modulator  3010 , a frequency segment deparser  3060 , an OFDM  3012 , an Inverse Fast Fourier Transform (IFFT) module  3015 , a GI module  3045 , and a transmitter front end  3040 . The encoder  3008  of transmitter  3006  receives and encodes a data stream destined for transmission from the MAC logic circuitry  3091  with, e.g., a binary convolutional coding (BCC), a low-density parity check coding (LDPC), and/or the like. After coding, scrambling, puncturing and post-FEC (forward error correction) padding, a stream parser  3064  may optionally divide the data bit streams at the output of the FEC encoder into groups of bits. The frequency segment parser  3007  may receive data stream from encoder  3008  or streams from the stream parser  3064  and optionally parse each data stream into two or more frequency segments to build a contiguous or non-contiguous bandwidth based upon smaller bandwidth frequency segments. The interleaver  3009  may interleave rows and columns of bits to prevent long sequences of adjacent noisy bits from entering a BCC decoder of a receiver. 
     The modulator  3010  may receive the data stream from interleaver  3009  and may impress the received data blocks onto a sinusoid of a selected frequency for each stream via, e.g., mapping the data blocks into a corresponding set of discrete amplitudes of the sinusoid, or a set of discrete phases of the sinusoid, or a set of discrete frequency shifts relative to the frequency of the sinusoid. In some embodiments, the output of modulator  3010  may optionally be fed into the frequency segment deparser  3060  to combine frequency segments in a single, contiguous frequency bandwidth of, e.g., 320 MHz. Other embodiments may continue to process the frequency segments as separate data streams for, e.g., a non-contiguous 160+160 MHz bandwidth transmission. 
     After the modulator  3010 , the data stream(s) are fed to an OFDM  3012 . The OFDM  3012  may comprise a space-time block coding (STBC) module  3011 , and a digital beamforming (DBF) module  3014 . The STBC module  3011  may receive constellation points from the modulator  3010  corresponding to one or more spatial streams and may spread the spatial streams to a greater number of space-time streams. Further embodiments may omit the STBC. 
     The OFDM  3012  impresses or maps the modulated data formed as OFDM symbols onto a plurality of orthogonal subcarriers, so the OFDM symbols are encoded with the subcarriers or tones. The OFDM symbols may be fed to the DBF module  3014 . Generally, digital beam forming uses digital signal processing algorithms that operate on the signals received by, and transmitted from, an array of antenna elements. Transmit beamforming processes the channel state to compute a steering matrix that is applied to the transmitted signal to optimize reception at one or more receivers. This is achieved by combining elements in a phased antenna array in such a way that signals at particular angles experience constructive interference while others experience destructive interference. 
     The IFFT module  3015  may perform an inverse discrete Fourier transform (IDFT) on the OFDM symbols to map on the subcarriers. The guard interval (GI) module  3045  may insert guard intervals by prepending to the symbol a circular extension of itself. The GI module  3045  may also comprise windowing to optionally smooth the edges of each symbol to increase spectral decay. 
     The output of the GI module  3045  may enter the radio  3042  to convert the time domain signals into radio signals by combining the time domain signals with subcarrier frequencies to output into the transmitter front end module (TX FEM)  3040 . The transmitter front end  3040  may comprise a with a power amplifier (PA)  3044  to amplify the signal and prepare the signal for transmission via the antenna array  3018 . In many embodiments, entrance into a spatial reuse mode by a communications device such as a station or AP may reduce the amplification by the PA  3044  to reduce channel interference caused by transmissions. 
     The transceiver  3000  may also comprise duplexers  3016  connected to antenna array  3018 . The antenna array  3018  radiates the information bearing signals into a time-varying, spatial distribution of electromagnetic energy that can be received by an antenna of a receiver. In several embodiments, the receiver  3004  and the transmitter  3006  may each comprise its own antenna(s) or antenna array(s). 
     The transceiver  3000  may comprise a receiver  3004  for receiving, demodulating, and decoding information bearing communication signals. The receiver  3004  may comprise a receiver front-end module (RX FEM)  3050  to detect the signal, detect the start of the packet, remove the carrier frequency, and amplify the subcarriers via a low noise amplifier (LNA)  3054  to output to the radio  3052 . The radio  3052  may convert the radio signals into time domain signals to output to the GI module  3055  by removing the subcarrier frequencies from each tone of the radio signals. 
     The receiver  3004  may comprise a GI module  3055  and a fast Fourier transform (FFT) module  3019 . The GI module  3055  may remove the guard intervals and the windowing and the FFT module  3019  may transform the communication signals from the time domain to the frequency domain. 
     The receiver  3004  may also comprise an OFDM  3022 , a frequency segment parser  3062 , a demodulator  3024 , a deinterleaver  3025 , a frequency segment deparser  3027 , a stream deparser  3066 , and a decoder  3026 . An equalizer may output the weighted data signals for the OFDM packet to the OFDM  3022 . The OFDM  3022  extracts signal information as OFDM symbols from the plurality of subcarriers onto which information-bearing communication signals are modulated. 
     The OFDM  3022  may comprise a DBF module  3020 , and an STBC module  3021 . The received signals are fed from the equalizer to the DBF module  3020 . The DBF module  3020  may comprise algorithms to process the received signals as a directional transmission directed toward to the receiver  3004 . And the STBC module  3021  may transform the data streams from the space-time streams to spatial streams. 
     The output of the STBC module  3021  may enter a frequency segment parser  3062  if the communication signal is received as a single, contiguous bandwidth signal to parse the signal into, e.g., two or more frequency segments for demodulation and deinterleaving. 
     The demodulator  3024  demodulates the spatial streams. Demodulation is the process of extracting data from the spatial streams to produce demodulated spatial streams. The deinterleaver  3025  may deinterleave the sequence of bits of information. The frequency segment deparser  3027  may optionally deparse frequency segments as received if received as separate frequency segment signals or may deparse the frequency segments determined by the optional frequency segment parser  3062 . The decoder  3026  decodes the data from the demodulator  3024  and transmits the decoded information, the MPDU, to the MAC logic circuitry  3091 . 
     The MAC logic circuitry  3091  may parse the MPDU based upon a format defined in the communications device for a frame to determine the particular type of frame by determining the type value and the subtype value. The MAC logic circuitry  3091  may then interpret the remainder of MPDU. 
     While the description of  FIG.  3    focuses primarily on a single spatial stream system for simplicity, many embodiments are capable of multiple spatial stream transmissions and use parallel data processing paths for multiple spatial streams from the PHY logic circuitry  3092   through to transmission. Further embodiments may include the use of multiple encoders to afford implementation flexibility. 
       FIG.  4 A  depicts an embodiment of a flowchart of a process  4000  to implement transition logic circuitry such as the transition logic circuitry discussed in  FIGS.  1 - 3   . At element  4005 , transition logic circuitry of a first AP MLD (e.g., the transition logic circuitry  1220  of the AP MLD  1210 ) may receive a medium access control (MAC) frame from a non-AP MLD (e.g., the transition logic circuitry  1250  of the MLD  1230 ) to inform the first AP MLD of a pending transition from links between the non-AP MLD and the first AP MLD to new links between the non-AP MLD and a second AP MLD, wherein both the first AP MLD and the second AP MLD are affiliated with a non-collocated AP MLD. The MAC frame may, for example, comprise an association frame, a reassociation frame, a new MAC frame, another MAC management frame, a MAC control frame, and/or the like. In some embodiments, the receipt of the MAC frame may advantageously allow the first AP MLD to share buffer status and scoreboard information with the second AP MLD more quickly to reduce delays involved with the pending transition. 
     The transition logic circuitry of the first AP MLD may receive and parse a first MAC request frame to add the new links between the non-AP MLD and the second AP MLD (element  4010 ). The transition logic circuitry of the first AP MLD may parse the first MAC request frame to determine a value of a receiver address (RA) in a first address field, wherein the address field comprises a receiver address (RA) that identifies the first AP MLD to determine that the MAC request frame is addressed to the first AP MLD. The transition logic circuitry of the first AP MLD may parse the MAC request frame to determine a recipient MAC address or MLD ID field comprising a value, wherein the value comprises a MAC address to identify the non-collocated AP MLD, a MLD identifier (ID) of the non-collocated AP MLD, and/or a flag to indicate whether the MAC frame is addressed to the non-collocated AP MLD or is addressed to the first AP MLD. Furthermore, the first AP MLD may parse an add link field in the frame header or the frame body of the MAC request frame to determine whether or not the MAC request is a request to add the new links while maintaining the current links between the non-AP MLD and the first AP MLD. 
     The transition logic circuitry of the first AP MLD may further parse an ML element including per-STA elements in the link info field of the ML element to determine profile information for the new links to add, link IDs for AP MLD STAs of the second AP MLD. After parsing the MAC request frame, the transition logic circuitry of the first AP MLD may compare profile information of the non-AP STAs of the non-AP MLD against profile information about the AP STAs of the second AP MLD to determine if the non-AP STAs of the non-AP MLD can operate on the new links with the second AP MLD. In some embodiments, the first AP MLD may also determine whether other factors related to, e.g., traffic and data throughput impact a decision to accept the new links requested by the non-AP MLD. 
     If the first AP MLD determines that adding the new links is acceptable, the first AP MLD may generate and cause transmission of a first MAC response frame to indicate that the addition of the new links is successful (element  4015 ). 
     After transmission of the first MAC response frame, the first AP MLD may receive and parse a second MAC request frame from the non-AP MLD to associate the new links with one or more TIDs and to remove the TIDs associated with the current links between the non-AP MLD and the first AP MLD (element  4020 ). In some embodiments, the first AP MLD may receive a MAC request frame to associate the new links with the one or more TIDs while maintaining the current links with the current TIDs and then receive another MAC request frame to remove the association between the current links with the current TIDs. In other embodiments, the first AP MLD may receive a single MAC request frame to both associate the new links with one or more TIDs and to remove the TIDs associated with the current links between the non-AP MLD and the first AP MLD. 
     After receiving and parsing the one or more second MAC request frames to negotiate the TIDs for the new links and the current links (also referred to herein as the old links), the first AP MLD may modify the TIDs based on bitmaps for the TIDs in one or two TID-to-Link mapping elements in the frame body of the second MAC request frame(s). Thereafter, the new links between the non-AP MLD and the second AP MLD may be enabled and the current links or old links between the non-AP MLD and the first AP MLD may be disabled. 
     The transition logic circuitry of the first AP MLD and/or the transition logic circuitry of the second AP MLD may generate and transmit a MAC response frame via one or more of the new links to the non-AP MLD to confirm that the new links are enabled, and the old links are disabled (element  4025 ). 
     Once the new links are enabled and the old links are disabled, the first AP MLD, the second AP MLD, or the non-AP MLD may initiate a process to remove the old links. Removal of the old links may, advantageously reduce the number of entries maintained for links associated with the non-AP MLD and allow for additional entries for additional links for the non-AP MLD. In the present embodiment, the first AP MLD or the second AP MLD may receive and parse a third MAC request frame via one or more of the new links to remove the old links (element  4030 ). In many embodiments, the third MAC request frame to remove the old links may comprise a remove links field comprising a flag to indicate that links may be deleted while maintaining other links unchanged and a ML element with a per-STA profile subelement that includes that link IDs for each of the old links to remove or tear down. 
     After generating the third MAC response frame to inform the non-AP MLD that the old links are removed, the transition logic circuitry of the first AP MLD or the second AP MLD may cause transmission of the MAC response frame to the non-AP MLD (element  4035 ) via a PHY and an antenna of the first AP MLD or the PHY of the second AP MLD. 
     In some embodiments, the transition logic circuitry of the first AP MLD or the second AP MLD may generate a fourth MAC frame to re-set the link IDs of the non-AP MLD (element  4040 ) by inclusion of link info in an ML element and in per-STA profile subelements of the ML element to change old information associated with the link IDs for the old links based on complete profiles for the AP STAs for the new links. 
     In some embodiments, the first AP MLD may also receive and parse a MAC discovery frame from non-AP MLD to determine the current status of the links between the maintained in entries of the mapping table such as the mapping table  2246  shown in  FIG.  2 N  determine the current status of link messages to advantageously avoid missing messages. Such embodiments may allow any link to confirm the current status of the mapping table in case link messages were missed. 
       FIG.  4 B  depicts another embodiment of a flowchart of a process  4100  to implement transition logic circuitry such as the transition logic circuitry discussed in  FIGS.  1 - 3   . At element  4105 , transition logic circuitry of a non-AP MLD (e.g., the transition logic circuitry  1250  of the MLD  1250 ) may generate and cause transmission of a medium access control (MAC) frame from a non-AP MLD (e.g., the transition logic circuitry  1220  of the MLD  1210 ) to inform the first AP MLD of a pending transition from links between the non-AP MLD and the first AP MLD to new links between the non-AP MLD and a second AP MLD, wherein both the first AP MLD and the second AP MLD are affiliated with a con-collocated AP MLD. In some embodiments, the non-AP MLD may also transmit one or more block acknowledgements (BA) to the second AP MLD to update the buffer status and scoreboard directly and, in some embodiments, the non-AP MLD may transmit an UL buffer status to the second AP MLD. 
     The transition logic circuitry of the non-AP MLD may generate and cause transmission of a first MAC request frame to add the new links between the non-AP MLD and the second AP MLD (element  4110 ). The transition logic circuitry of the non-AP MLD may determine values for and generate the first MAC request frame with a value for a receiver address (RA) in a first address field, to identify the first AP MLD as a recipient of the first MAC request frame. The transition logic circuitry of the non-AP MLD may determine a value for a recipient MAC address or MLD ID field, wherein the value comprises a MAC address to identify the non-collocated AP MLD, a MLD identifier (ID) of the non-collocated AP MLD, and/or a flag to indicate whether the MAC frame is addressed to the non-collocated AP MLD or is addressed to the first AP MLD. Furthermore, the non-AP MLD may determine a value for an add link field in the frame header or the frame body of the first MAC request frame to identify whether or not the MAC request is a request to add the new links while maintaining the current links between the non-AP MLD and the first AP MLD. 
     The transition logic circuitry of the first AP MLD may further determine values for field of an ML element including per-STA elements in the link info field of the ML element to identify profile information for the new links to add and link IDs for AP MLD STAs of the second AP MLD. 
     After causing transmission of the first MAC request frame, the non-AP MLD may receive and parse a first MAC response frame from the first AP MLD to indicate that the addition of the new links is successful (element  4115 ). 
     The non-AP MLD may generate and cause transmission of a second MAC request frame from the non-AP MLD to associate the new links with one or more TIDs and to remove the TIDs associated with the current links between the non-AP MLD and the first AP MLD (element  4120 ). In some embodiments, the non-AP MLD may cause transmission of the second MAC request frame to associate the new links with the one or more TIDs while maintaining the current links with the current TIDs and then receive another second MAC request frame to remove the association between the current links with the current TIDs. In other embodiments, the non-AP MLD may cause transmission of a single second MAC request frame to both associate the new links with one or more TIDs and to remove the TIDs associated with the current links between the non-AP MLD and the first AP MLD. 
     After transmission of the one or more second MAC request frames to negotiate the TIDs for the new links and the current links, the non-AP MLD may receive and parse a MAC response frame via one or more of the new links to the non-AP MLD to confirm success in enablement of the new links and disablement of the old links (element  4125 ). 
     Once the new links are enabled and the old links are disabled, the non-AP MLD, the first AP MLD, or the second AP MLD may initiate a process to remove the old links. In the present embodiment, the non-AP MLD may generate and transmit a third MAC request frame to the first AP MLD or the second AP MLD via one or more of the new links to remove the old links (element  4130 ). In many embodiments, the third MAC request frame to remove the old links may comprise a remove links field to indicate a link delete functionality and a ML element with a per-STA profile subelement that includes that link IDs for each of the old links to remove or tear down. 
     After the old links are removed, the transition logic circuitry of the non-AP MLD may receive a third MAC response frame (element  4135 ) via a PHY and an antenna of the non-AP MLD. 
     In some embodiments, the transition logic circuitry of the non-AP MLD may receive and parse a fourth MAC frame to re-set the link IDs of the non-AP MLD (element  4140 ) via link info in an ML element and in per-STA profile subelements of the ML element to change old information associated with the link IDs for the old links based on complete profiles for the AP STAs for the new links. 
     In some embodiments, the non-AP MLD may also generate and cause transmission of a MAC discovery frame to the first AP MLD to determine the current status of the links between the maintained in entries of the mapping table such as the mapping table  2246  shown in  FIG.  2 N  determine the current status of link messages to advantageously avoid missing messages. 
       FIGS.  4 C-D  depict embodiments of flowcharts  4200  and  4300  to transmit, receive, and interpret communications with a frame. Referring to  FIG.  4 C , the flowchart  4200  may begin with receiving an MU frame from the wireless communications I/F  1216  of the AP MLD  1210  by the wireless communications I/Fs (such as wireless communications I/F  1246  of the MLD  1230 , MLD  1290 , MLD  1292 , and MLD  1296  as shown in  FIG.  1 C . The MAC logic circuitry, such as the MAC logic circuitry  3091  in  FIG.  1 C , of each MLD of MLD  1230 , MLD  1290 , MLD  1292 , and MLD  1296  may operate in conjunction with transition logic circuitry  3093  to generate a management frame to transmit to the AP MLD  1210  as a reassociation request or response frame or a TID-to-Link mapping request or response frame and may pass the frame as an MAC protocol data unit (MPDU) to a PHY logic circuitry such as the PHY logic circuitry  3092  in  FIG.  1 C  as a PSDU to include in a PHY frame. The PHY logic circuitry may also encode and transform the PSDU into OFDM symbols for transmission to the AP MLD  1210 . The PHY logic circuitry may generate a preamble to prepend the PHY service data unit (PSDU) (the MPDU) to form a PHY protocol data unit (PPDU) for transmission (element  4210 ). 
     A physical layer device such as the transmitter  3006  in  FIG.  3    or the wireless network interfaces  1222  and  1252  in  FIG.  1 A  may convert the PPDU to a communication signal via a radio (element  4215 ). The transmitter may then transmit the communication signal via the antenna coupled with the radio (element  4220 ). 
     Referring to  FIG.  4 D , the flowchart  4300  begins with a receiver of a device such as the receiver  3004  in  FIG.  3    receiving a communication signal via one or more antenna(s) such as an antenna element of antenna array  3018  (element  4310 ). The receiver may convert the communication signal into an MPDU in accordance with the process described in the preamble (element  4315 ). More specifically, the received signal is fed from the one or more antennas to a DBF such as the DBF  220 . The DBF transforms the antenna signals into information signals. The output of the DBF is fed to OFDM such as the OFDM  3022  in  FIG.  3   . The OFDM extracts signal information from the plurality of subcarriers onto which information-bearing signals are modulated. Then, the demodulator such as the demodulator  3024  demodulates the signal information via, e.g., BPSK, 16-QAM (quadrature amplitude modulation), 64-QAM, 256-QAM, 1024-QAM, or 4096-QAM with a forward error correction (FEC) coding rate (½, ⅔, ¾, or ⅚). And the decoder such as the decoder  3026  decodes the signal information from the demodulator via, e.g., BCC or LDPC, to extract the MPDU and pass or communicate the MPDU to MAC layer logic circuitry such as MAC logic circuitry  3091  (element  4320 ). 
     When received at the MAC layer circuitry, the MPDU may be a MAC Service Data Unit (MSDU). The MAC logic circuitry in conjunction with transition logic circuitry may determine frame field values from the MSDU (MPDU from PHY) (element  4325 ) such as the management frame fields in the management frame shown in  FIGS.  2 F- 2 I . For instance, the MAC logic circuitry may determine frame field values such as the type and subtype field values to determine that the MAC frame is the management frame and, more specifically, an association request frame, a reassociation request frame, an association response frame, a reassociation response frame, a TID-to-Link request frame, and/or a TID-to-Link response frame. 
       FIG.  5    shows a functional diagram of an exemplary communication station  500 , in accordance with one or more example embodiments of the present disclosure. In one embodiment,  FIG.  5    illustrates a functional block diagram of a communication station that may be suitable for use as an AP MLD  1005  ( FIG.  1 A ) or a user device  1028  ( FIG.  1 A ) in accordance with some embodiments. The communication station  500  may also be suitable for use as other user device(s)  1020  such as the user devices  1024  and/or  1026 . The user devices  1024  and/or  1026  may include, e.g., a handheld device, a mobile device, a cellular telephone, a smartphone, a tablet, a netbook, a wireless terminal, a laptop computer, a wearable computer device, a femtocell, a high data rate (HDR) subscriber station, an access point, an access terminal, or other personal communication system (PCS) device. 
     The communication station  500  may include communications circuitry  502  and a transceiver  510  for transmitting and receiving signals to and from other communication stations using one or more antennas  501 . The communications circuitry  502  may include circuitry that can operate the physical layer (PHY) communications and/or medium access control (MAC) communications for controlling access to the wireless medium, and/or any other communications layers for transmitting and receiving signals. The communication station  500  may also include processing circuitry  506  and memory  508  arranged to perform the operations described herein. In some embodiments, the communications circuitry  502  and the processing circuitry  506  may be configured to perform operations detailed in the above figures, diagrams, and flows. 
     In accordance with some embodiments, the communications circuitry  502  may be arranged to contend for a wireless medium and configure frames or packets for communicating over the wireless medium. The communications circuitry  502  may be arranged to transmit and receive signals. The communications circuitry  502  may also include circuitry for modulation/demodulation, upconversion/downconversion, filtering, amplification, etc. In some embodiments, the processing circuitry  506  of the communication station  500  may include one or more processors. In other embodiments, two or more antennas  501  may be coupled to the communications circuitry  502  arranged for sending and receiving signals. The memory  508  may store information for configuring the processing circuitry  506  to perform operations for configuring and transmitting message frames and performing the various operations described herein. The memory  508  may include any type of memory, including non-transitory memory, for storing information in a form readable by a machine (e.g., a computer). For example, the memory  508  may include a computer-readable storage device, read-only memory (ROM), random-access memory (RAM), magnetic disk storage media, optical storage media, flash-memory devices and other storage devices and media. 
     In some embodiments, the communication station  500  may be part of a portable wireless communication device, such as a personal digital assistant (PDA), a laptop or portable computer with wireless communication capability, a web tablet, a wireless telephone, a smartphone, a wireless headset, a pager, an instant messaging device, a digital camera, an access point, a television, a medical device (e.g., a heart rate monitor, a blood pressure monitor, etc.), a wearable computer device, or another device that may receive and/or transmit information wirelessly. 
     In some embodiments, the communication station  500  may include one or more antennas  501 . The antennas  501  may include one or more directional or omnidirectional antennas, including, for example, dipole antennas, monopole antennas, patch antennas, loop antennas, microstrip antennas, or other types of antennas suitable for transmission of RF signals. In some embodiments, instead of two or more antennas, a single antenna with multiple apertures may be used. In these embodiments, each aperture may be considered a separate antenna. In some multiple-input multiple-output (MIMO) embodiments, the antennas may be effectively separated for spatial diversity and the different channel characteristics that may result between each of the antennas and the antennas of a transmitting station. 
     In some embodiments, the communication station  500  may include one or more of a keyboard, a display, a non-volatile memory port, multiple antennas, a graphics processor, an application processor, speakers, and other mobile device elements. The display may be an LCD screen including a touch screen. 
     Although the communication station  500  is illustrated as having several separate functional elements, two or more of the functional elements may be combined and may be implemented by combinations of software-configured elements, such as processing elements including digital signal processors (DSPs), and/or other hardware elements. For example, some elements may include one or more microprocessors, DSPs, field- programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), radio- frequency integrated circuits (RFICs) and combinations of various hardware and logic circuitry for performing at least the functions described herein. In some embodiments, the functional elements of the communication station  500  may refer to one or more processes operating on one or more processing elements. 
     Certain embodiments may be implemented in one or a combination of hardware, firmware, and software. Other embodiments may also be implemented as instructions stored on a computer-readable storage device, which may be read and executed by at least one processor to perform the operations described herein. A computer-readable storage device may include any non-transitory memory mechanism for storing information in a form readable by a machine (e.g., a computer). For example, a computer-readable storage device may include read-only memory (ROM), random-access memory (RAM), magnetic disk storage media, optical storage media, flash-memory devices, and other storage devices and media. In some embodiments, the communication station  500  may include one or more processors and may be configured with instructions stored on a computer-readable storage device. 
       FIG.  6    illustrates a block diagram of an example of a machine  600  or system upon which any one or more of the techniques (e.g., methodologies) discussed herein may be performed. For instance, the machine may comprise an AP MLD such as the AP MLD  1005  and/or one of the user devices  1020  shown in  FIG.  1 A . In other embodiments, the machine  600  may operate as a standalone device or may be connected (e.g., networked) to other machines. In a networked deployment, the machine  600  may operate in the capacity of a server machine, a client machine, or both in server-client network environments. In an example, the machine  600  may act as a non-AP MLD or an AP MLD in network environments. The machine  600  may be a personal computer (PC), a tablet PC, a set-top box (STB), a personal digital assistant (PDA), a mobile telephone, a wearable computer device, a web appliance, a network router, a switch or bridge, or any machine capable of executing instructions (sequential or otherwise) that specify actions to be taken by that machine, such as link management. Further, while only a single machine is illustrated, the term “machine” shall also be taken to include any collection of machines that individually or jointly execute a set (or multiple sets) of instructions to perform any one or more of the methodologies discussed herein, such as cloud computing, software as a service (SaaS), or other computer cluster configurations. 
     Examples, as described herein, may include or may operate on logic or a number of components, modules, or mechanisms. Modules are tangible entities (e.g., hardware) capable of performing specified operations when operating. A module includes hardware. In an example, the hardware may be specifically configured to carry out a specific operation (e.g., hardwired). In another example, the hardware may include configurable execution units (e.g., transistors, circuits, etc.) and a computer readable medium containing instructions where the instructions configure the execution units to carry out a specific operation when in operation. The configuring may occur under the direction of the execution units or a loading mechanism. Accordingly, the execution units are communicatively coupled to the computer-readable medium when the device is operating. In this example, the execution units may be a member of more than one module. For example, under operation, the execution units may be configured by a first set of instructions to implement a first module at one point in time and reconfigured by a second set of instructions to implement a second module at a second point in time. 
     The machine (e.g., computer system)  600  may include a hardware processor  602  (e.g., a central processing unit (CPU), a graphics processing unit (GPU), a hardware processor core, or any combination thereof), a main memory  604  and a static memory  606 , some or all of which may communicate with each other via one or more interlinks (e.g., buses or high-speed interconnects)  608 . Note that the single set of interlinks  608  may be representative of the physical interlinks in some embodiments but is not representative of the physical interlinks  608  in other embodiments. For example, the main memory  604  may couple directly with the hardware processor  602  via high-speed interconnects or a main memory bus. The high-speed interconnects typically connect two devices, and the bus is generally designed to interconnect two or more devices and include an arbitration scheme to provide fair access to the bus by the two or more devices. 
     The machine  600  may further include a power management device  632 , a graphics display device  610 , an alphanumeric input device  612  (e.g., a keyboard), and a user interface (UI) navigation device  614  (e.g., a mouse). In an example, the graphics display device  610 , alphanumeric input device  612 , and UI navigation device  614  may be a touch screen display. The machine  600  may additionally include a storage device (i.e., drive unit)  616 , a signal generation device  618  (e.g., a speaker), a transition logic circuitry  619 , a network interface device/transceiver  620  coupled to antenna(s)  630 , and one or more sensors  628 , such as a global positioning system (GPS) sensor, a compass, an accelerometer, or other sensor. The machine  600  may include an output controller  634 , such as a serial (e.g., universal serial bus (USB), parallel, or other wired or wireless (e.g., infrared (IR), near field communication (NFC), etc.) connection to communicate with or control one or more peripheral devices (e.g., a printer, a card reader, etc.)). The operations in accordance with one or more example embodiments of the present disclosure may be carried out by a baseband processor such as the baseband processing circuitry  1218  and/or  1248  shown in  FIG.  1 C . The baseband processor may be configured to generate corresponding baseband signals. The baseband processor may further include physical layer (PHY) and medium access control layer (MAC) circuitry and may further interface with the hardware processor  602  for generation and processing of the baseband signals and for controlling operations of the main memory  604 , the storage device  616 , and/or the transition logic circuitry  619 . The baseband processor may be provided on a single radio card, a single chip, or an integrated circuit (IC). 
     The storage device  616  may include a machine readable medium  622  on which is stored one or more sets of data structures or instructions  624  (e.g., software) embodying or utilized by any one or more of the techniques or functions described herein. The instructions  624  may also reside, completely or at least partially, within the main memory  604 , within the static memory  606 , or within the hardware processor  602  during execution thereof by the machine  600 . In an example, one or any combination of the hardware processor  602 , the main memory  604 , the static memory  606 , or the storage device  616  may constitute machine-readable media. 
     The transition logic circuitry  619  may carry out or perform any of the operations and processes in relation to transition of a non-AP MLD from STA links with a first collocated AP MLD affiliated with a non-collocated AP MLD to a second collocated AP MLD affiliated with a non-collocated AP MLD via a MAC frame such as a MAC request frame and/or a MAC response frame transmitted in a, e.g., 2.4 GHz, 5 GHz, or 6 GHz channel or the like (e.g., flowchart of process  4000  shown in  FIG.  4 A  and flowchart of process  4100  shown in  FIG.  4 B ) described and shown herein. It is understood that the above are only a subset of what the transition logic circuitry  619  may be configured to perform and that other functions included throughout this disclosure may also be performed by the transition logic circuitry  619 . 
     While the machine-readable medium  622  is illustrated as a single medium, the term “machine-readable medium” may include a single medium or multiple media (e.g., a centralized or distributed database, and/or associated caches and servers) configured to store the one or more instructions  624 . 
     Various embodiments may be implemented fully or partially in software and/or firmware. This software and/or firmware may take the form of instructions contained in or on a non-transitory computer-readable storage medium. Those instructions may then be read and executed by one or more processors to enable performance of the operations described herein. The instructions may be in any suitable form, such as but not limited to source code, compiled code, interpreted code, executable code, static code, dynamic code, and the like. Such a computer-readable medium may include any tangible non-transitory medium for storing information in a form readable by one or more computers, such as but not limited to read only memory (ROM); random access memory (RAM); magnetic disk storage media; optical storage media; a flash memory, etc. 
     The term “machine-readable medium” may include any medium that is capable of storing, encoding, or carrying instructions for execution by the machine  600  and that cause the machine  600  to perform any one or more of the techniques of the present disclosure, or that is capable of storing, encoding, or carrying data structures used by or associated with such instructions. Non-limiting machine-readable medium examples may include solid-state memories and optical and magnetic media. In an example, a massed machine-readable medium includes a machine-readable medium with a plurality of particles having resting mass. Specific examples of massed machine-readable media may include non-volatile memory, such as semiconductor memory devices (e.g., electrically programmable read-only memory (EPROM), or electrically erasable programmable read-only memory (EEPROM)) and flash memory devices; magnetic disks, such as internal hard disks and removable disks; magneto-optical disks; and CD-ROM and DVD- ROM disks. 
     The instructions  624  may further be transmitted or received over a communications network  626  using a transmission medium via the network interface device/transceiver  620  utilizing any one of a number of transfer protocols (e.g., frame relay, internet protocol (IP), transmission control protocol (TCP), user datagram protocol (UDP), hypertext transfer protocol (HTTP), etc.). Example communications networks may include a local area network (LAN), a wide area network (WAN), a packet data network (e.g., the Internet), mobile telephone networks (e.g., cellular networks), plain old telephone (POTS) networks, wireless data networks (e.g., Institute of Electrical and Electronics Engineers (IEEE) 802.11 family of standards known as Wi-Fi®, IEEE 802.16 family of standards known as WiMax®), IEEE  802 .15.4 family of standards, and peer-to-peer (P2P) networks, among others. In an example, the network interface device/transceiver  620  may include one or more physical jacks (e.g., Ethernet, coaxial, or phone jacks) or one or more antennas to connect to the communications network  626 . In an example, the network interface device/transceiver  620  may include a plurality of antennas to wirelessly communicate using at least one of single-input multiple-output (SIMO), multiple-input multiple-output (MIMO), or multiple-input single-output (MISO) techniques. The term “transmission medium” shall be taken to include any intangible medium that is capable of storing, encoding, or carrying instructions for execution by the machine  600  and includes digital or analog communications signals or other intangible media to facilitate communication of such software. 
     The operations and processes described and shown above may be carried out or performed in any suitable order as desired in various implementations. Additionally, in certain implementations, at least a portion of the operations may be carried out in parallel. Furthermore, in certain implementations, less than or more than the operations described may be performed. 
       FIG.  7    illustrates an example of a storage medium  7000  to store association logic such as logic to implement the transition logic circuitry  619  shown in  FIG.  6    and/or the other logic discussed herein to transition a non-AP MLD affiliated a non-collocated AP MLD from links with a first collocated AP MLD to links with a second collocated AP MLD. Storage medium  7000  may comprise an article of manufacture. In some examples, storage medium  7000  may include any non-transitory computer readable medium or machine-readable medium, such as an optical, magnetic or semiconductor storage. Storage medium  7000  may store diverse types of computer executable instructions, such as instructions to implement logic flows and/or techniques described herein. Examples of a computer readable or machine-readable storage medium may include any tangible media capable of storing electronic data, including volatile memory or non-volatile memory, removable or non-removable memory, erasable or non-erasable memory, writeable or re-writeable memory, and so forth. Examples of computer executable instructions may include any suitable type of code, such as source code, compiled code, interpreted code, executable code, static code, dynamic code, object-oriented code, visual code, and the like. 
       FIG.  8    illustrates an example computing platform  8000  such as the MLD STAs  1210 ,  1230 ,  1290 ,  1292 ,  1294 ,  1296 , and  1298  in  FIG.  1 C . In some examples, as shown in  FIG.  8   , computing platform  8000  may include a processing component  8010 , other platform components or a communications interface  8030  such as the wireless network interfaces  1222  and  1252  shown in  FIG.  1 C . According to some examples, computing platform  8000  may be a computing device such as a server in a system such as a data center or server farm that supports a manager or controller for managing configurable computing resources as mentioned above. In some embodiments, the computing platform may comprise a mobile device such as a smart phone, a tablet, a notebook, a laptop, a headset, a power amplifier, a television, a speaker, a video/audio streaming device, a stereo, and/or the like. 
     According to some examples, processing component  8010  may execute processing operations or logic for apparatus  8015  described herein. Processing component  8010  may include various hardware elements, software elements, or a combination of both. Examples of hardware elements may include devices, logic devices, components, processors, microprocessors, circuits, processor circuits, circuit elements (e.g., transistors, resistors, capacitors, inductors, and so forth), integrated circuits (ICs), application specific integrated circuits (ASIC), programmable logic devices (PLD), digital signal processors (DSP), field programmable gate array (FPGA), memory units, logic gates, registers, semiconductor device, chips, microchips, chip sets, and so forth. Examples of software elements, which may reside in the storage medium  8020 , may include software components, programs, applications, computer programs, application programs, device drivers, system programs, software development programs, machine programs, operating system software, middleware, firmware, software modules, routines, subroutines, functions, methods, procedures, software interfaces, application program interfaces (API), instruction sets, computing code, computer code, code segments, computer code segments, words, values, symbols, or any combination thereof. While discussions herein describe elements of embodiments as software elements and/or hardware elements, decisions to implement an embodiment using hardware elements and/or software elements may vary in accordance with any number of design considerations or factors, such as desired computational rate, power levels, heat tolerances, processing cycle budget, input data rates, output data rates, memory resources, data bus speeds and other design or performance constraints. 
     In some examples, other platform components  8025  may include common computing elements, such as one or more processors, multi-core processors, co-processors, memory units, chipsets, controllers, peripherals, interfaces, oscillators, timing devices, video cards, audio cards, multimedia input/output (I/O) components (e.g., digital displays), power supplies, and so forth. Examples of memory units may include without limitation various types of computer readable and machine readable storage media in the form of one or more higher speed memory units, such as read-only memory (ROM), random-access memory (RAM), dynamic RAM (DRAM), Double-Data-Rate DRAM (DDRAM), synchronous DRAM (SDRAM), static RAM (SRAM), programmable ROM (PROM), erasable programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), flash memory, polymer memory such as ferroelectric polymer memory, ovonic memory, phase change or ferroelectric memory, silicon-oxide-nitride-oxide-silicon (SONOS) memory, magnetic or optical cards, an array of devices such as Redundant Array of Independent Disks (RAID) drives, solid state memory devices (e.g., universal serial bus (USB) memory), solid state drives (SSD) and any other type of storage media suitable for storing information. 
     In some examples, communications interface  8030  may include logic and/or features to support a communication interface. For these examples, communications interface  8030  may include one or more communication interfaces that operate according to various communication protocols or standards to communicate over direct or network communication links. Direct communications may occur via use of communication protocols or standards described in one or more industry standards (including progenies and variants) such as those associated with the Peripheral Component Interconnect (PCI) Express specification. Network communications may occur via use of communication protocols or standards such as those described in one or more Ethernet standards promulgated by the Institute of Electrical and Electronics Engineers (IEEE). For example, one such Ethernet standard may include IEEE 802.3-2012, Carrier sense Multiple access with Collision Detection (CSMA/CD) Access Method and Physical Layer Specifications, Published in December 2012 (hereinafter “IEEE 802.3”). Network communication may also occur according to one or more OpenFlow specifications such as the OpenFlow Hardware Abstraction API Specification. Network communications may also occur according to Infiniband Architecture Specification, Volume 1, Release 1.3, published in March 2015 (“the Infiniband Architecture specification”). 
     Computing platform  8000  may be part of a computing device that may be, for example, a server, a server array or server farm, a web server, a network server, an Internet server, a workstation, a mini-computer, a main frame computer, a supercomputer, a network appliance, a web appliance, a distributed computing system, multiprocessor systems, processor-based systems, or combination thereof. Accordingly, various embodiments of the computing platform  8000  may include or exclude functions and/or specific configurations of the computing platform  8000  described herein. 
     The components and features of computing platform  8000  may comprise any combination of discrete circuitry, ASICs, logic gates and/or single chip architectures. Further, the features of computing platform  8000  may comprise microcontrollers, programmable logic arrays and/or microprocessors or any combination of the foregoing where suitably appropriate. Note that hardware, firmware and/or software elements may be collectively or individually referred to herein as “logic”. 
     One or more aspects of at least one example may comprise representative instructions stored on at least one machine-readable medium which represents various logic within the processor, which when read by a machine, computing device or system causes the machine, computing device or system to fabricate logic to perform the techniques described herein. Such representations, known as “IP cores” may be stored on a tangible, machine readable medium and supplied to various customers or manufacturing facilities to load into the fabrication machines that make the logic or processor. 
     Some examples may include an article of manufacture or at least one computer-readable medium. A computer-readable medium may include a non-transitory storage medium to store logic. In some examples, the non-transitory storage medium may include one or more types of computer-readable storage media capable of storing electronic data, including volatile memory or non-volatile memory, removable or non-removable memory, erasable or non-erasable memory, writeable or re-writeable memory, and so forth. In some examples, the logic may include various software elements, such as software components, programs, applications, computer programs, application programs, system programs, machine programs, operating system software, middleware, firmware, software modules, routines, subroutines, functions, methods, procedures, software interfaces, API, instruction sets, computing code, computer code, code segments, computer code segments, words, values, symbols, or any combination thereof. 
     According to some examples, a computer-readable medium may include a non-transitory storage medium to store or maintain instructions that when executed by a machine, computing device or system, cause the machine, computing device or system to perform methods and/or operations in accordance with the described examples. The instructions may include any suitable type of code, such as source code, compiled code, interpreted code, executable code, static code, dynamic code, and the like. The instructions may be implemented according to a predefined computer language, manner, or syntax, for instructing a machine, computing device or system to perform a certain function. The instructions may be implemented using any suitable high-level, low-level, object-oriented, visual, compiled and/or interpreted programming language. 
     Some examples may be described using the expression “coupled” and “connected” along with their derivatives. These terms are not necessarily intended as synonyms for each other. For example, descriptions using the terms “connected” and/or “coupled” may indicate that two or more elements are in direct physical or electrical contact with each other. The term “coupled,” however, may also mean that two or more elements are not in direct contact with each other, but yet still co-operate or interact with each other. 
     Advantages of Some Embodiments 
     Several embodiments have one or more potentially advantages effects. For instance, transition logic circuitry, advantageously may generate a MAC (re)association request frame or an authentication frame to associate the MAC (re)association request frame or an authentication frame with the non-collocated AP MLD. Transition logic circuitry may advantageously parse a MAC (re)association request frame or an authentication frame to associate the MAC (re)association request frame or an authentication frame with the non-collocated AP MLD. Transition logic circuitry may, advantageously, determine that the MAC (re)association request frame or an authentication frame is addressed to the non-collocated AP MLD based on the value in a new recipient field. Transition logic circuitry may, advantageously, determine that the MAC (re)association request/response frame or TID-to-Link mapping request/response frame is addressed to the non-collocated AP MLD based on the value in a new recipient field. Transition logic circuitry may, advantageously, determine that the MAC (re)association request/response frame requests addition of links while maintaining current links. Transition logic circuitry may, advantageously, determine that the MAC (re)association request frame or a TID-to-Link mapping request/response frame is addressed to the non-collocated AP MLD based on the value in a new recipient field comprising a flag, a MAC address, and/or a MLD ID. Transition logic circuitry may, advantageously generate a new link ID for a link associated with a non-collocated AP MLD. Transition logic circuitry may advantageously generate a mapping table entry to store the new link ID and to associate the new link ID with a link ID and MAC address of an AP MLD affiliated with the collocated AP MLD. Transition logic circuitry may advantageously generate an association response frame with the new link ID to associate a new link ID with a collocated AP MLD link ID and a collocated AP MLD MAC address or MAC ID. Transition logic circuitry may advantageously describe links with one or more AP STAs of one or more AP MLDs affiliated with a collocated AP MLD in per-STA profile subelements of a ML element of an association request frame or reassociation request frame. Transition logic circuitry may, advantageously, perform pre-transition operations to decrease delays associated with transitioning between AP MLDs Transition logic circuitry may, advantageously, enable new links and disable old links to maintain a manageable number of links. 
     Examples of Further Embodiments 
     The following examples pertain to further embodiments. Specifics in the examples may be used anywhere in one or more embodiments. 
     Example 1, an apparatus comprising: a memory; and logic circuitry of a first access point (AP) multilink device (MLD) affiliated with a non-collocated AP MLD coupled with the memory to: parse a first medium access control (MAC) request frame to add new links between a non-AP MLD and a second AP MLD affiliated with the non-collocated AP MLD, the first MAC request frame to comprise a first address field, wherein the first address field comprises a receiver address (RA) that identifies the first AP MLD; a recipient field comprising a value to identify the non-collocated AP MLD; a link add field to request addition of one or more new links and to maintain current links associated with STAs of the non-AP MLD unchanged; and one or more per-STA profile elements comprising new links to add; generate a first MAC response frame to confirm addition of new links; and cause transmission of the first MAC response frame to the non-AP MLD. In Example 2, the apparatus of claim 1, the logic circuitry to further: parse a second MAC request frame comprising a first address field, wherein the first address field comprises a receiver address (RA) that identifies the first AP MLD; a second address field, wherein the second address field comprises a MAC address of the non-AP MLD; a recipient ID field comprising a value to identify a non-collocated AP MLD; a non-collocated link ID comprising a value to identify a link of a non-collocated AP MLD; wherein the frame body comprises a bitmap of links for one or more traffic identifiers (TIDs), the bitmap of links to identify link IDs associated with the non-AP STA to associate with the one or more TIDs; and cause transmission of a second MAC response frame to the non-AP MLD, the second MAC response frame to indicate successful enablement of the new links by association of the new links with the one or more TIDs. In Example 3, the apparatus of claim 1, the logic circuitry to further: parse a third MAC request frame comprising a remove links field comprising a flag to indicate that links may be deleted while maintaining other links unchanged; a first address field, wherein the first address field comprises a receiver address (RA) that identifies the first AP MLD; a second address field, wherein the second address field comprises a MAC address of the non-AP MLD; a recipient ID field comprising a value to identify a non-collocated AP MLD; and one or more per-STA profile subelements of a multi-link element of the MAC response frame, each of the per-STA profile subelements to comprise a link ID field comprising a link ID for a link between a non-AP STA of the non-AP MLD and an AP STA affiliated with the non-collocated AP MLD; and cause transmission of a third MAC response frame to the non-AP MLD to indicate successful removal of the old links. In Example 4, the apparatus of claim 3, the logic circuitry to generate a fourth MAC frame to re-set link IDs of the non-AP MLD. In Example 5, the apparatus of claim 3, the logic circuitry to generate a new link ID for a link added between a non-AP STA of the non-AP MLD and an AP STA of a second AP MLD affiliated with the non-collocated AP MLD. In Example 6, the apparatus of claim 5, the logic circuitry to generate a mapping table entry for the new link ID, wherein the mapping table entry comprises a collocated AP MLD field and a non-collocated AP MLD field, the collocated AP MLD field comprising an identifier for the second AP MLD and a second link ID; the non-collocated AP MLD field comprising the new link ID. In Example 7, the apparatus of claim 5, the logic circuitry to include the new link ID in a non-collocation link ID field of a STA control field of a link info field of the multi-link element of the MAC response frame. In Example 8, the apparatus of claim 1, the logic circuitry to further share buffer statuses and scoreboards with a second AP MLD in response to receipt of a fourth MAC frame from the non-AP MLD to prepare for a transition to the new links between the non-AP MLD and the second AP MLD. In Example 9, the apparatus of claim 1, the logic circuitry comprising baseband processing circuitry and further comprising a radio coupled with the baseband processing circuitry, and one or more antennas coupled with the radio to receive the first MAC request frame. In Example 10, the apparatus of claim 1, wherein the first MAC request frame comprises an association request frame or a reassociation request frame. In Example 11, the apparatus of claim 1, wherein the value to identify the non-collocated AP MLD is different from a MAC address of the first AP MLD or the value of an MLD ID for the first AP MLD. In Example 12, the apparatus of claim 1, the logic circuitry to use, for authentication, the same security keys for different groups of collocated AP STAs of a non-collocated AP MLD, wherein the different groups of collocated AP STAs are non-collocated. In Example 13, the apparatus of claim 1, the logic circuitry to use, for authentication, different security keys for different groups of collocated AP STAs of a non-collocated AP MLD, wherein the different groups of collocated AP STAs are non-collocated. In Example 14, the apparatus of claim 1, the logic circuitry to parse the first MAC request frame to determine the value of the flag, wherein the value of the flag comprises one or more bits, the value to indicate whether the MAC frame is addressed to the non-collocated AP MLD or addressed to the first AP MLD, wherein the first AP MLD is a collocated AP MLD. 
     Example 15, a non-transitory computer-readable medium, comprising instructions, which when executed by a processor, cause the processor to perform operations to: parse a first medium access control (MAC) request frame to add new links between a non-AP MLD and a second AP MLD affiliated with the non-collocated AP MLD, the first MAC request frame to comprise a first address field, wherein the first address field comprises a receiver address (RA) that identifies the first AP MLD; a recipient field comprising a value to identify the non-collocated AP MLD; a link add field to request addition of one or more new links and to maintain current links associated with STAs of the non-AP MLD unchanged; and one or more per-STA profile elements comprising new links to add; generate a first MAC response frame to confirm addition of new links; and cause transmission of the first MAC response frame to the non-AP MLD. In Example 16, the non-transitory computer-readable medium of claim 15, the operations to further: parse a second MAC request frame comprising a first address field, wherein the first address field comprises a receiver address (RA) that identifies the first AP MLD; a second address field, wherein the second address field comprises a MAC address of the non-AP MLD; a recipient ID field comprising a value to identify a non-collocated AP MLD; a non-collocated link ID comprising a value to identify a link of a non-collocated AP MLD; wherein the frame body comprises a bitmap of links for one or more traffic identifiers (TIDs), the bitmap of links to identify link IDs associated with the non-AP STA to associate with the one or more TIDs; and cause transmission of a second MAC response frame to the non-AP MLD, the second MAC response frame to indicate successful enablement of the new links by association of the new links with the one or more TIDs. In Example 17, the non-transitory computer-readable medium of claim 15, the operations to further: parse a third MAC request frame comprising a remove links field comprising a flag to indicate that links may be deleted while maintaining other links unchanged; a first address field, wherein the first address field comprises a receiver address (RA) that identifies the first AP MLD; a second address field, wherein the second address field comprises a MAC address of the non-AP MLD; a recipient ID field comprising a value to identify a non-collocated AP MLD; and one or more per-STA profile subelements of a multi-link element of the MAC response frame, each of the per-STA profile subelements to comprise a link ID field comprising a link ID for a link between a non-AP STA of the non-AP MLD and an AP STA affiliated with the non-collocated AP MLD; and cause transmission of a third MAC response frame to the non-AP MLD to indicate successful removal of the old links. In Example 18, the non-transitory computer-readable medium of claim 15, the operations to generate a fourth MAC frame to re-set link IDs of the non-AP MLD. In Example 19, the non-transitory computer-readable medium of claim 16, the operations to generate a new link ID for a link added between a non-AP STA of the non-AP MLD and an AP STA of a second AP MLD affiliated with the non-collocated AP MLD. In Example 20, the non-transitory computer-readable medium of claim 19, the operations to generate a mapping table entry for the new link ID, wherein the mapping table entry comprises a collocated AP MLD field and a non-collocated AP MLD field, the collocated AP MLD field comprising an identifier for the second AP MLD and a second link ID; the non-collocated AP MLD field comprising the new link ID. In Example 19, the non-transitory computer-readable medium of claim 19, the operations to include the new link ID in a non-collocation link ID field of a STA control field of a link info field of the multi-link element of the MAC response frame. In Example 20, the non-transitory computer-readable medium of claim 13, the operations to further share buffer statuses and scoreboards with a second AP MLD in response to receipt of a fourth MAC frame from the non-AP MLD to prepare for a transition to the new links between the non-AP MLD and the second AP MLD. In Example 21, the non-transitory computer-readable medium of claim 13, wherein the first MAC request frame comprises an association request frame or a reassociation request frame. In Example 22, the non-transitory computer-readable medium of claim 13, wherein the value to identify the non-collocated AP MLD is different from a MAC address of the first AP MLD or the value of an MLD ID for the first AP MLD. In Example 23, the non-transitory computer-readable medium of claim 13, the operations to parse the first MAC request frame to determine the value of the flag, wherein the value of the flag comprises one or more bits, the value to indicate whether the MAC frame is addressed to the non-collocated AP MLD or addressed to the first AP MLD, wherein the first AP MLD is a collocated AP MLD. 
     Example 24 is a method comprising: parsing a first medium access control (MAC) request frame to add new links between a non-AP MLD and a second AP MLD affiliated with the non-collocated AP MLD, the first MAC request frame to comprise a first address field, wherein the first address field comprises a receiver address (RA) that identifies the first AP MLD; a recipient field comprising a value to identify the non-collocated AP MLD; a link add field to request addition of one or more new links and to maintain current links associated with STAs of the non-AP MLD unchanged; and one or more per-STA profile elements comprising new links to add; generate a first MAC response frame to confirm addition of new links; and causing transmission of the first MAC response frame to the non-AP MLD. In Example 25, the method of claim 24, further comprising: parsing a second MAC request frame comprising a first address field, wherein the first address field comprises a receiver address (RA) that identifies the first AP MLD; a second address field, wherein the second address field comprises a MAC address of the non-AP MLD; a recipient ID field comprising a value to identify a non-collocated AP MLD; a non-collocated link ID comprising a value to identify a link of a non-collocated AP MLD; wherein the frame body comprises a bitmap of links for one or more traffic identifiers (TIDs), the bitmap of links to identify link IDs associated with the non-AP STA to associate with the one or more TIDs; and causing transmission of a second MAC response frame to the non-AP MLD, the second MAC response frame to indicate successful enablement of the new links by association of the new links with the one or more TIDs. In Example 26, the method of claim 24, further comprising: parsing a third MAC request frame comprising a remove links field comprising a flag to indicate that links may be deleted while maintaining other links unchanged; a first address field, wherein the first address field comprises a receiver address (RA) that identifies the first AP MLD; a second address field, wherein the second address field comprises a MAC address of the non-AP MLD; a recipient ID field comprising a value to identify a non-collocated AP MLD; and one or more per-STA profile subelements of a multi-link element of the MAC response frame, each of the per-STA profile subelements to comprise a link ID field comprising a link ID for a link between a non-AP STA of the non-AP MLD and an AP STA affiliated with the non-collocated AP MLD; and causing transmission of a third MAC response frame to the non-AP MLD to indicate successful removal of the old links .In Example 27, the method of claim 26, further comprising generating a fourth MAC frame to re-set link IDs of the non-AP MLD. In Example 28, the method of claim 27, further comprising generating a new link ID for a link added between a non-AP STA of the non-AP MLD and an AP STA of a second AP MLD affiliated with the non-collocated AP MLD. In Example 29, the method of claim 27, further comprising generating a mapping table entry for the new link ID, wherein the mapping table entry comprises a collocated AP MLD field and a non-collocated AP MLD field, the collocated AP MLD field comprising an identifier for the second AP MLD and a second link ID; the non-collocated AP MLD field comprising the new link ID. In Example 30, the method of claim 24, further comprising including the new link ID in a non-collocation link ID field of a STA control field of a link info field of the multi-link element of the MAC response frame. In Example 31, the method of claim 24, wherein the value to identify the non-collocated AP MLD is different from a MAC address of the first AP MLD or the value of an MLD ID for the first AP MLD. In Example 32, the method of claim 24, further comprising sharing buffer statuses and scoreboards with a second AP MLD in response to receipt of a fourth MAC frame from the non-AP MLD to prepare for a transition to the new links between the non-AP MLD and the second AP MLD. In Example 33, the method of claim 24, wherein the first MAC request frame comprises an association request frame or a reassociation request frame. In Example 34, the method of claim 24, wherein the value to identify the non-collocated AP MLD is different from a MAC address of the first AP MLD or the value of an MLD ID for the first AP MLD. In Example 35, the method of claim 24, further comprising using, for authentication, the same security keys for different groups of collocated AP STAs of a non-collocated AP MLD, wherein the different groups of collocated AP STAs are non-collocated. In Example 36, the method of claim 24, further comprising using, for authentication, different security keys for different groups of collocated AP STAs of a non-collocated AP MLD, wherein the different groups of collocated AP STAs are non-collocated. In Example 37, the method of claim 24, further comprising parsing the first MAC request frame to determine the value of the flag, wherein the value of the flag comprises one or more bits, the value to indicate whether the MAC frame is addressed to the non-collocated AP MLD or addressed to the first AP MLD, wherein the first AP MLD is a collocated AP MLD. 
     Example 38, an apparatus comprising: a memory; and logic circuitry of a non-AP multilink device (MLD) coupled with the memory to: generate a first medium access control (MAC) request frame to add new links between a non-AP MLD and a second AP MLD affiliated with the non-collocated AP MLD, the MAC request frame to comprise a first address field, wherein the first address field comprises a receiver address (RA) that identifies the first AP MLD; a recipient field comprising a value to identify the non-collocated AP MLD; a link add field to request addition of one or more new links and to maintain current links associated with STAs of the non-AP MLD unchanged; and one or more per-STA profile elements comprising new links to add; cause transmission of the first MAC request frame to the first AP MLD; and receive a first MAC response frame from the first AP MLD. In Example 39, the apparatus of claim 38, the logic circuitry to further: generate a second MAC request frame comprising a first address field, wherein the first address field comprises a receiver address (RA) that identifies the first AP MLD; a second address field, wherein the second address field comprises a MAC address of the non-AP MLD; a recipient ID field comprising a value to identify a non-collocated AP MLD; a non-collocated link ID comprising a value to identify a link of a non-collocated AP MLD; wherein the frame body comprises a bitmap of links for one or more traffic identifiers (TIDs), the bitmap of links to identify link IDs associated with the non-AP STA to associate with the one or more TIDs; cause transmission of the second MAC request frame to the first AP MLD; and receive a second MAC response frame from the first AP MLD, the second MAC response frame to indicate successful enablement of the new links by association of the new links with the one or more TIDs. In Example 40, the apparatus of claim 39, the second MAC request frame comprises a TID-to-Link mapping request frame. In Example 41, the apparatus of claim 38, the logic circuitry to further: generate a third MAC request frame comprising a remove links field comprising a flag to indicate that links may be deleted while maintaining other links unchanged; a first address field, wherein the first address field comprises a receiver address (RA) that identifies the first AP MLD; a second address field, wherein the second address field comprises a MAC address of the non-AP MLD; a recipient ID field comprising a value to identify a non-collocated AP MLD; and one or more per-STA profile subelements of a multi-link element of the MAC response frame, each of the per-STA profile subelements to comprise a link ID field comprising a link ID for a link between a non-AP STA of the non-AP MLD and an AP STA affiliated with the non-collocated AP MLD; cause transmission of a third MAC request frame to the AP MLD; and receive a third MAC response frame from the first AP MLD to indicate successful removal of the old links. In Example 42, the apparatus of claim 41, the third MAC request frame comprises an association request frame, a reassociation request frame, a new MAC frame, or a disassociation frame. In Example 43, the apparatus of claim 42, the logic circuitry to receive a fourth MAC frame to re-set link IDs of the non-AP MLD. In Example 44, the apparatus of claim 38, wherein the logic circuitry comprises baseband processing circuitry and further comprising a radio coupled with the baseband processing circuitry, and one or more antennas coupled with the radio to transmit the MAC request frame. In Example 45, the apparatus of claim 38, wherein the first MAC request frame comprises an association request frame or a reassociation request frame. In Example 46, the apparatus of claim 38, the logic circuitry to determine, for generation of a frame header of the first MAC request frame, the value for the non-collocated AP MLD ID, the value of the flag, or a combination thereof. In Example 47, the apparatus of claim 38, the logic circuitry to determine, for generation of a frame header of the first MAC request frame, the value for the add link field, the value comprising one or more bits. 
     Example 48, a non-transitory computer-readable medium, comprising instructions, which when executed by a processor, cause the processor to perform operations to: generate a first medium access control (MAC) request frame to add new links between a non-AP MLD and a second AP MLD affiliated with the non-collocated AP MLD, the MAC request frame to comprise a first address field, wherein the first address field comprises a receiver address (RA) that identifies the first AP MLD; a recipient field comprising a value to identify the non-collocated AP MLD; a link add field to request addition of one or more new links and to maintain current links associated with STAs of the non-AP MLD unchanged; and one or more per-STA profile elements comprising new links to add; cause transmission of the first MAC request frame to the first AP MLD; and receive a first MAC response frame from the first AP MLD. In Example 49, the non-transitory computer-readable medium of claim 48, operations to further: generate a second MAC request frame comprising a first address field, wherein the first address field comprises a receiver address (RA) that identifies the first AP MLD; a second address field, wherein the second address field comprises a MAC address of the non-AP MLD; a recipient ID field comprising a value to identify a non-collocated AP MLD; a non-collocated link ID comprising a value to identify a link of a non-collocated AP MLD; wherein the frame body comprises a bitmap of links for one or more traffic identifiers (TIDs), the bitmap of links to identify link IDs associated with the non-AP STA to associate with the one or more TIDs; cause transmission of the second MAC request frame to the first AP MLD; and receive a second MAC response frame from the first AP MLD, the second MAC response frame to indicate successful enablement of the new links by association of the new links with the one or more TIDs. In Example 50, the non-transitory computer-readable medium of claim 49, the second MAC request frame comprises a TID-to-Link mapping request frame. In Example 51, the non-transitory computer-readable medium of claim 48, the operations to further generate a third MAC request frame comprising a remove links field comprising a flag to indicate that links may be deleted while maintaining other links unchanged; a first address field, wherein the first address field comprises a receiver address (RA) that identifies the first AP MLD; a second address field, wherein the second address field comprises a MAC address of the non-AP MLD; a recipient ID field comprising a value to identify a non-collocated AP MLD; and one or more per-STA profile subelements of a multi-link element of the MAC response frame, each of the per-STA profile subelements to comprise a link ID field comprising a link ID for a link between a non-AP STA of the non-AP MLD and an AP STA affiliated with the non-collocated AP MLD; cause transmission of a third MAC request frame to the AP MLD; and receive a third MAC response frame from the first AP MLD to indicate successful removal of the old links. In Example 52, the non-transitory computer-readable medium of claim 51, the third MAC request frame comprises an association request frame, a reassociation request frame, a new MAC frame, or a disassociation frame. In Example 53, the non-transitory computer-readable medium of claim 48, the operations to receive a fourth MAC frame to re-set link IDs of the non-AP MLD. In Example 54, the non-transitory computer-readable medium of claim 48, wherein the first MAC request frame comprises an association request frame or a reassociation request frame. In Example 55, the non-transitory computer-readable medium of claim 48, the operations to determine, for generation of a frame header of the first MAC request frame, the value for the non-collocated AP MLD ID, the value of the flag, or a combination thereof. 
     Example 56 is a method comprising: generating a first medium access control (MAC) request frame to add new links between a non-AP MLD and a second AP MLD affiliated with the non-collocated AP MLD, the MAC request frame to comprise a first address field, wherein the first address field comprises a receiver address (RA) that identifies the first AP MLD; a recipient field comprising a value to identify the non-collocated AP MLD; a link add field to request addition of one or more new links and to maintain current links associated with STAs of the non-AP MLD unchanged; and one or more per-STA profile elements comprising new links to add; causing transmission of the first MAC request frame to the first AP MLD; and receiving a first MAC response frame from the first AP MLD. In Example 57, the method of claim 56, further comprising: generating a second MAC request frame comprising a first address field, wherein the first address field comprises a receiver address (RA) that identifies the first AP MLD; a second address field, wherein the second address field comprises a MAC address of the non-AP MLD; a recipient ID field comprising a value to identify a non-collocated AP MLD; a non-collocated link ID comprising a value to identify a link of a non-collocated AP MLD; wherein the frame body comprises a bitmap of links for one or more traffic identifiers (TIDs), the bitmap of links to identify link IDs associated with the non-AP STA to associate with the one or more TIDs; causing transmission of the second MAC request frame to the first AP MLD; and receiving a second MAC response frame from the first AP MLD, the second MAC response frame to indicate successful enablement of the new links by association of the new links with the one or more TIDs. In Example 58, the method of claim 57, the second MAC request frame comprises a TID-to-Link mapping request frame. In Example 59, the method of claim 56, further comprising generating a third MAC request frame comprising a remove links field comprising a flag to indicate that links may be deleted while maintaining other links unchanged; a first address field, wherein the first address field comprises a receiver address (RA) that identifies the first AP MLD; a second address field, wherein the second address field comprises a MAC address of the non-AP MLD; a recipient ID field comprising a value to identify a non-collocated AP MLD; and one or more per-STA profile subelements of a multi-link element of the MAC response frame, each of the per-STA profile subelements to comprise a link ID field comprising a link ID for a link between a non-AP STA of the non-AP MLD and an AP STA affiliated with the non-collocated AP MLD; causing transmission of a third MAC request frame to the AP MLD; and receiving a third MAC response frame from the first AP MLD to indicate successful removal of the old links. In Example 60, the method of claim 59, the third MAC request frame comprises an association request frame, a reassociation request frame, a new MAC frame, or a disassociation frame. In Example 61, the method of claim 59, further comprising receiving a fourth MAC frame to re-set link IDs of the non-AP MLD. In Example 62, the method of claim 56, wherein the first MAC request frame comprises an association request frame or a reassociation request frame. In Example 63, the method of claim 56, further comprising determining, for determine, for generation of a frame header of the first MAC request frame, the value for the non-collocated AP MLD ID, the value of the flag, or a combination thereof. In Example 64, the method of claim 56, further comprising determining, for generation of a frame header of the first MAC request frame, the value for the add link field, the value comprising one or more bits.