Patent Publication Number: US-2022224492-A1

Title: Systems and methods for customizing wireless communication beacons and transmitting wireless communication beacons

Description:
RELATED APPLICATIONS 
     This application is a continuation of U.S. patent application Ser. No. 16/663,095, filed on Oct. 24, 2019, which is continuation-in-part of U.S. patent application Ser. No. 16/425,575, filed on May 29, 2019, now U.S. Pat. No. 10,897,727, which claims benefit of priority to (a) U.S. Provisional Patent Application Ser. No. 62/677,423, filed on May 29, 2018, (b) U.S. Provisional Patent Application Ser. No. 62/678,104, filed on May 30, 2018, and (c) U.S. Provisional Patent Application Ser. No. 62/701,970, filed on Jul. 23, 2018. U.S. patent application Ser. No. 16/663,095 also claims benefit of priority to (a) U.S. Provisional Patent Application Ser. No. 62/750,152, filed on Oct. 24, 2018 and (b) U.S. Provisional Patent Application Ser. No. 62/757,502, filed on Nov. 8, 2018. Each of the aforementioned applications is incorporated herein by reference. 
    
    
     BACKGROUND 
     Wireless communication systems may use licensed radio frequency (RF) spectrum, unlicensed RF spectrum, or a combination of licensed and unlicensed RF spectrum. Cellular wireless communication systems primarily use licensed RF spectrum, while Wi-Fi wireless communication systems use unlicensed RF spectrum. Wi-Fi wireless communication systems have become very popular, partly due to the relatively low-cost and wide-availability of Wi-Fi hardware. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a block diagram illustrating a continuous wireless communication system, according to an embodiment. 
         FIG. 2  is a block diagram illustrating an example of the  FIG. 1  wireless communication system handing off a moving user equipment station between two wireless termination points managed by a common access controller. 
         FIG. 3  is a block diagram illustrating an example of the  FIG. 1  wireless communication system handing off a moving user equipment station between two wireless termination points managed by different respective access controllers. 
         FIG. 4  is a block diagram illustrating an example of the  FIG. 1  wireless communication system handing off a stationary user equipment station between two wireless termination points managed by a common access controller. 
         FIG. 5  is a block diagram illustrating an example of the  FIG. 1  wireless communication system handing off a stationary user equipment station between two wireless termination points managed by different respective access controllers. 
         FIG. 6  is a block diagram illustrating an example of the  FIG. 1  wireless communication system handing off a moving user equipment station between two wireless termination points operating on different respective wireless channels. 
         FIG. 7  is a block diagram illustrating an access controller, according to an embodiment. 
         FIG. 8-10  illustrative respective hypothetical examples of signal strength tables. 
         FIG. 11  is a dataflow diagram illustrating one example of a make-before-break handoff of a user equipment station in the  FIG. 1  wireless communication system, according to an embodiment. 
         FIG. 12  is a graph illustrating one example of how a source wireless termination point may reduce transmit power during a make-before-break handoff of a user equipment station, for data frames addressed to the user equipment station, according to an embodiment. 
         FIG. 13  is a flow chart illustrating a method for providing continuous wireless communication service, according to an embodiment. 
         FIG. 14  is a flow chart illustrating a method for authenticating and associating a user equipment station, according an embodiment. 
         FIG. 15  is a flow chart illustrating a method for associating a user equipment station, according an embodiment. 
         FIG. 16  is a flow chart illustrating a method for handing-off a user equipment station, according to an embodiment. 
         FIG. 17  is a block diagram of a wireless communication system where several wireless termination points are managed by a plurality of access controllers, according to an embodiment. 
         FIG. 18  is a dataflow diagram illustrating one example of transitioning access controllers during a handoff of the user equipment station, according to an embodiment. 
         FIG. 19  is a block diagram illustrating a wireless communication system configured to customize wireless communication beacons, according to an embodiment. 
         FIG. 20  is a flow chart illustrating a method for customizing wireless communication beacons, according to an embodiment. 
         FIG. 21  is a dataflow diagram illustrating one example of a wireless termination point transmitting beacons to a user equipment station. 
         FIG. 22  is a dataflow diagram illustrating another example of a wireless termination point transmitting beacons to a user equipment station. 
         FIG. 23  is a dataflow diagram illustrating another example of a wireless termination point transmitting beacons to a user equipment station. 
         FIG. 24  is a dataflow diagram illustrating another example of a wireless termination point transmitting beacons to a user equipment station. 
         FIG. 25  is a block diagram illustrating a wireless communication system configured to aggregate a Unicast beacon with one or more additional data frames into an aggregated data unit, according to an embodiment. 
         FIG. 26  is a block diagram illustrating a wireless communication system configured to transmit one or more Unicast beacons via one or more subcarriers of a wireless communication signal, according to an embodiment. 
         FIG. 27  is a block diagram of a wireless termination point, according to an embodiment. 
     
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
     While Wi-Fi wireless communication systems benefit from low-cost and widely-available hardware, Wi-Fi wireless communication systems may provide sub-optimal performance. For example, in a conventional Wi-Fi wireless communication system, a connection between a user equipment (UE) station and a wireless access point (WAP) is interrupted as the UE station roams among WAPs. Additionally, in a conventional Wi-Fi wireless communication system including multiple WAPs, UE stations may not be optimally distributed among the WAPs, resulting in some WAPs being overloaded and some WAPs being underutilized. Such sub-optimal UE station distribution stems from conventional Wi-Fi wireless communication systems being unmanaged, i.e. there is no system-level control of which UE stations are served by which WAP. Instead, each UE station unilaterally determines which WAP to connect to, potentially resulting in sub-optimal UE station distribution. For example, a UE station near a congested WAP may connect to the congested WAP because the congested WAP offers a highest received signal strength indication (RSSI), even though a more-distant, but uncongested, WAP would provide better service to the UE station. 
     Disclosed herein are systems and methods for providing continuous wireless communication service, which may at least partially overcome one or more of the above-discussed drawbacks of conventional wireless communication systems. The new systems and methods provide continuous wireless communication service during a handoff of a UE station between two wireless termination points (WTPs). Additionally, certain embodiments are configured to manage UE station connections to WTPs, such as to help optimize distribution of UE stations among WTPs. Furthermore, some embodiments do not require changes to existing UE stations, thereby promoting ease and low-cost of implementation. Moreover, particular embodiments may provide individualized wireless communication service, e.g. different respective types of wireless communication service to multiple UE stations connected to a common WTP. 
     Although the new systems and methods are discussed below primarily with respect to Wi-Fi wireless communication applications, the new systems and methods are not limited to Wi-Fi applications. Rather, the new systems and methods could be applied to other wireless communication systems, such as other wireless communication systems operating according to an Institute of Electrical and Electronic Engineers (IEEE) 802.11 standard, or variations, extensions, and/or successors thereof. 
       FIG. 1  is a block diagram illustrating a continuous wireless communication system  100 , which is one embodiment of the new continuous wireless communication systems developed by Applicant. Wireless communication system  100  includes one or more WTPs  102 , one or more access controllers (ACs)  104 , and an authentication, authorization, and accounting services (AAA) server  106 . ACs  104  and AAA server  106  are optionally part of a core network  108  of wireless communication system  100 . ACs  104  are communicatively coupled by one or more communication buses  107 . Communication buses  107  include, for example, wireline and/or wireless communication buses. Core network  108  may include additional elements without departing from the scope hereof. For example, in some embodiments, core network  108  includes one or more elements (not shown) to support encryption between UE stations  110  and core network  108 , so that encryption does not need to be handled by WTPs  102 . In this document, specific instances of an item may be referred to by use of a numeral in parentheses (e.g., WTP  102 ( 1 )) while numerals without parentheses refer to any such item (e.g., WTPs  102 ). 
     The number of WTPs  102  and/or ACs  104  in wireless communication system  100  may vary without departing from the scope hereof. Additionally, two or more of the elements of wireless communication system  100  could be combined without departing from the scope hereof. For example, AAA server  106  could incorporated into one or more ACs  104 , and as another example, two or more ACs  104  could be combined into a single device configured to operate as two or more logically distinct ACs  104 . As yet another example, one or more ACs  104  could be combined with one or more WTPs  102 . Furthermore, any of the elements of  FIG. 1  could include multiple sub-elements. All of the elements of wireless communication network  100  need not be owned or managed by a single party. For example, core network  108  could be managed by one party, and WTPs  102  could be managed by one or more other parties. 
     Each WTP  102  is configured to convert electrical or optical signals to wireless signals, and vice versa, to enable one or more UE stations  110  to wirelessly communicate with core network  108 . In some embodiments, WTPs  102  operate according to a Wi-Fi-based standard or other IEEE 802.11-based standard. Although WTPs  102  are illustrated as being discrete elements, in some embodiments, two or more WTPs  102  are co-packaged. For example, in one embodiment, WTP  102 ( 1 ) includes a 2.4 GHz RF transceiver and WTP  102 ( 2 ) includes a 5 GHz RF transceiver, and WTPs  102 ( 1 ) and  102 ( 2 ) are co-packaged to yield a dual-band wireless access point, i.e. a wireless access point supporting both 2.4 GHz and 5 GHz wireless communication. 
     Each UE station  110  communicates with a serving WTP  102  using RF signals. For example,  FIG. 1  illustrates WTP  102 ( 4 ) serving UE stations  110 ( 1 ) and  110 ( 2 ), such that UE stations  110 ( 1 ) and  110 ( 2 ) communicate with WTP  102 ( 4 ) via RF signals. Each UE station  110  is, for example, a mobile telephone, a computer, a set-top device, a data storage device, an Internet of Things (IoT) device, an entertainment device, a wireless access point (including, for example, eNBs, gNBs, and Wi-Fi APS acting as UEs), a computer networking device, a smartwatch, a wearable device with wireless capability, or a medical device. The number of UE stations  110  served by wireless communication system  100  may vary, and UE stations  110  are not necessarily part of wireless communication system  100 . In some embodiments, UE stations  110  are conventional UE stations, i.e. UE stations  110  not specially adapted for use in wireless communication system  100 . 
     Each AC  104  manages one or more respective WTPs  102 . In the example of  FIG. 1 , (a) AC  104 ( 1 ) manages WTPs  102 ( 1 )- 102 ( 3 ), (b) AC  104 ( 2 ) manages WTPs  102 ( 4 )- 102 ( 6 ), (c) AC  104 ( 3 ) manages WTPs  102 ( 7 )- 102 ( 9 ), and AC  104 ( 4 ) manages WTPs  102 ( 10 )- 102 ( 12 ). However, the number and identity of WTPs  102  managed by each AC  104  may vary. In this document, an AC  104  “manages” a WTP  102  at least by controlling connection of UE stations  110  to the WTP  102 . Access controllers  104  may optionally provide additional management functions, such as discussed below with respect to  FIG. 7 . ACs  104  communicate with each other via communication buses  107 , such as to coordinate handing-off of a UE station  110  between two WTPs  102  managed by different respective ACs  104 . 
     AAA server  106  is configured to assist ACs  104  in managing WTPs  102  by providing one or more of authentication, authorization, and accounting services to ACs  104 . For example, in some embodiments, AAA server  106  authenticates and authorizes UE stations  110  connecting to wireless communication system  100 , such as based on credentials received from UE stations  110  via a WTP  102  and an AC  104 . For example, in some embodiments, when a WTP  102  receives a probe request  112  from a UE station  110 , the WTP  102  communicates with AAA server  106 , e.g. via an AC  104 , to confirm that the UE station  110  is known to wireless communication system  100 , based on a media access control (MAC) address of the UE stations  110 . AAA server  106  may also assist ACs  104  in authenticating wireless communication system  100  for UE stations  110 . Connections between AAA server  106  and ACs  104  are not shown to promote illustrative clarity, although in some embodiments, AAA server  106  is communicatively coupled to ACs  104  via communication busses  107 . 
     Importantly, wireless communication system  100  is configured so that WTPs  102  transmit Unicast beacons  114  to particular UE stations  110 , instead of Broadcast beacons, where a “beacon” is a data structure, e.g. a data frame, including control information for use by a UE station  110 . For example,  FIG. 1  illustrates WTP  102 ( 4 ) transmitting a Unicast beacon  114 ( 1 ) to UE station  110 ( 1 ), and  FIG. 1  illustrates WTP  102 ( 4 ) transmitting a Unicast beacon  114 ( 2 ) to UE device  110 ( 2 ). An AC  104  causes a WTP  102  to initiate transmission of Unicast beacons  114  to a UE station  110  in response to (1) the WTP  102  receiving a probe request  112  from the UE station  110  and (2) the AC  104  confirming that the UE station  110  is known to wireless communication system  100 . A WTP  102  will also transmit a probe response  113  to a UE station  110  in response to receipt of a probe request  112  from the UE station  110 . 
     Unicast beacon  114  is intended to be processed by one specific UE station  110 , instead of by all UE stations  110  receiving the beacon. For example, Unicast beacon  114 ( 1 ) is intended to be processed solely by UE station  110 ( 1 ), and Unicast beacon  114 ( 2 ) is intended to be processed solely by UE station  110 ( 2 ). Accordingly, each Unicast beacon  114  includes an address of an intended recipient UE station  110 , such as in a destination address field of the Unicast beacon. For example, Unicast beacon  114 ( 1 ) includes an address ADDR 1 of UE station  110 ( 1 ) in a destination address field of Unicast beacon  114 ( 1 ), and Unicast beacon  114 ( 2 ) includes an address ADDR 2 of UE station  110 ( 2 ) in a destination address field of Unicast beacon  114 ( 2 ). A Broadcast beacon, in contrast, does not contain an address of a specific recipient UE station in its address field. WTPs  102  transmit Unicast beacons  114 , for example, under control of a respective AC  104 ( 1 ) and/or local controllers (not shown) within the WTPs  102 . Transmission of Unicast beacons  114 , instead of Broadcast beacons, helps conserve UE station  110  resources by eliminating the need for UE stations  110  to process all received beacons. Instead, a given UE station  110  need only process Unicast beacons  114  addressed to the particular UE station  110 . 
     Additionally, transmission of Unicast beacons  114 , instead of Broadcast beacons, helps, enables customization of the beacons for respective UE stations. For example, each Unicast beacon  114  includes a basic service set identifier (BSSID). Conventionally, a BSSID identifies a WTP sending a beacon, such that all beacons transmitted by a given WTP include a common BSSID associated with the WTP. In wireless communication system  100 , in contrast, a respective BSSID is associated with each UE station  110 . For example, Unicast beacon  114 ( 1 ) includes a BSSID 1 associated with UE station  110 ( 1 ), and Unicast beacon  114 ( 2 ) includes a BSSID 2 associated with UE station  110 ( 2 ). In some embodiments of wireless communication system  100 , two or more BSSIDs have different respective values. For example, in some embodiments, BSSID 1 and BSSID 2 have different respective values. However, two BSSIDs can have a common value in wireless communication system  100  without departing from the scope hereof. The fact that beacons  114  are Unicast, instead of Broadcast, enables two or more BSSIDs to have a common value while still being associated with respective UE stations  110 , because each UE station  110  will only process Unicast beacons that are addressed to it. Consequently, each UE station  110  will “see” only its own BSSID. 
     BSSIDs may be static in that they are permanently assigned to respective UE stations  110 . Alternately, BSSIDs may be dynamic in that they are assigned to respective UE stations  110  only while the UE stations are being served by wireless communication system  100 . BSSIDs are associated with respective UE stations  110 , for example, by AAA server  106  and/or by one or more ACs  104 . In some embodiments, a BSSID associated with a respective UE station  110  is unchanged as wireless communication system  100  hands-off the UE station between WTPs  102 , such as discussed below with respect to  FIGS. 2-6 . 
     Each Unicast beacon  114  further includes a service set identifier (SSID). For example,  FIG. 1  illustrates each Unicast beacon  114  including a SSID. In some embodiments, all Unicast beacons  114  include a common SSID, while in some other embodiments, the SSID may vary among Unicast beacons  114 . In certain embodiments, probe requests  112  are Wi-Fi-based probe requests or other IEEE 802.11-based probe requests, and Unicast beacons  114  are Wi-Fi-based beacons or other IEEE 802.11-based beacons. 
     In some embodiments, ACs  104  are configured to control WTPs  102  to provide different types of wireless communication service for different BSSIDs, thereby enabling wireless communication system  100  to provide individualized wireless communication service to UE stations  110 . For example, in a particular embodiment, AC  104 ( 2 ) is configured to associate a first and second type of wireless communication service with BSSID 1 and BSSID 2, respectively, such that WTP radio  102 ( 4 ) provides first and second types of wireless communication service to UE stations  110 ( 1 ) and  110 ( 2 ), respectively. The first and second types of wireless communication services have at least one differing wireless service characteristic, such as quality of service (QoS), maximum communication bandwidth, priority during emergencies, access to network services, and/or roaming privileges. For example, in a particular embodiment, AC  104 ( 2 ) associates BSSID 1 with a high-QoS tier and BSSID 2 with a low-QoS tier, such that UE station  110 ( 1 ) receives a higher QoS than UE station  110 ( 2 ). ACs  104  could be configured such that wireless communication system  100  provides more than two types of wireless communication service. It should be noted that certain embodiments of wireless communication system  100  are capable of providing individualized wireless communication service to UE stations  110  even if the UE stations operate under a common SSID, since wireless communication system  100  is capable of distinguishing UE stations  110  by their respective BSSIDs. 
     In certain embodiments, wireless communication system  100  is configured to hand-off a UE station  110  from one WTP  102  to another WTP  102  in response to movement of the UE station  110 , such as to maximize strength of WTP  102  RF signals received at the UE station  110 . For example,  FIG. 2  is a block diagram illustrating an example of wireless communication system  100  handing-off UE station  110 ( 2 ) from WTP  102 ( 4 ) to WTP  102 ( 6 ) as UE station  110 ( 2 ) moves  202  from Position A to Position B. In this example, AC  104 ( 2 ) controls WTPs  102 ( 4 ) and  102 ( 6 ) such that (a) WTP  102 ( 4 ) serves UE station  110 ( 2 ) when the UE station is in Position A, and (b) WTP  102 ( 6 ) serves UE station  110 ( 2 ) when the UE station is in Position B. 
     The BSSID associated with UE station  110 ( 2 ) remains unchanged as wireless communication system  100  hands-off UE station  110 ( 2 ) from WTP  102 ( 4 ) to WTP  102 ( 6 ). Accordingly,  FIG. 2  illustrates WTP  102 ( 6 ) transmitting a Unicast beacon  114 ( 3 ), where Unicast beacon  114 ( 3 ) includes the same BSSID (BSSID 2) as Unicast beacon  114 ( 2 ) transmitted by WTP  102 ( 4 ). Consequentially, wireless communication system  100  appears to UE station  110 ( 2 ) as having a single WTP  102  that provides continuous coverage as UE station  110 ( 2 ) moves from position A to position B. Additionally, any individual wireless communication service associated with UE station  110 ( 2 ) may follow UE station  110 ( 2 ) during the hand-off from WTP  102 ( 4 ) to WTP  102 ( 6 ) because the BSSID associated with UE station  110 ( 2 ) does not change during the handoff. Wireless communication system  100  may perform other hand-offs of UE stations  110  between WTPs  102  managed by a common AC  104  in a manner similar to that illustrated in  FIG. 2 . 
       FIG. 2  illustrates an example of wireless communication system  100  handing-off UE station  110 ( 2 ) between two WTPs  102  served by a common AC  104 . Additionally, certain embodiments of wireless communication system  100  are configured to hand-off a UE station  110  between two WTPs  102  managed by different respective ACs  104 . 
     For example,  FIG. 3  is a block diagram illustrating an example of wireless communication system  100  handing-off UE station  110 ( 1 ) from WTP  102 ( 4 ) to WTP  102 ( 7 ) as UE station  110 ( 1 ) moves  302  from Position C to Position D. In this example, AC  104 ( 2 ) controls WTP  102 ( 4 ) and AC  104 ( 3 ) controls WTP  102 ( 7 ) such that (a) WTP  102 ( 4 ) serves UE station  110 ( 1 ) when the UE station is in Position C, and (b) WTP  102 ( 7 ) serves UE station  110 ( 1 ) when the UE device is in Position D. ACs  104 ( 2 ) and  104 ( 3 ) communicate using communication buses  107 , for example, to coordinate the handoff. 
     The BSSID associated with UE station  110 ( 1 ) remains unchanged as wireless communication system  100  hands-off UE station  110 ( 1 ) between WTPs  102 ( 4 ) and  102 ( 7 ). Accordingly,  FIG. 3  illustrates WTP  102 ( 7 ) transmitting a Unicast beacon  114 ( 4 ), where Unicast beacon  114 ( 4 ) includes the same BSSID (BSSID 1) as Unicast beacon  114 ( 1 ) transmitted by WTP  102 ( 4 ). Consequentially, wireless communication system  100  appears to UE station  110 ( 1 ) as having a single WTP  102  that provides continuous coverage as UE station  110 ( 1 ) moves from Position C to Position D. Additionally, any individual wireless communication service associated with UE station  110 ( 1 ) may follow UE station  110 ( 1 ) during the hand-off from WTP  102 ( 4 ) to WTP  102 ( 7 ) because the BSSID associated with UE station  110 ( 1 ) does not change during the handoff. Wireless communication system  100  may perform other hand-offs of UE stations  110  between WTPs  102  managed by different ACs  104  in a manner similar to that illustrated in  FIG. 3 . 
     Additionally, certain embodiments of wireless communication system  100  are configured to handoff a UE station  110  between two WTPs  102  for reasons other than movement of the UE station. For example, some embodiments of wireless communication system  100  are configured to handoff a UE station  110  between a first and second WTPs  102  for one or more of the following reasons: (a) to relieve congestion at the first WTP  102 , e.g. in response to congestion at the first WTP  102  exceeding a threshold value, (b) to relieve congestion at an AC  104  managing the first WTP  102 , (c) to improve quality of wireless communication service to the UE station  110 , e.g. in response to the second WTP  102  having greater capacity than the first WTP  102  and/or the second WTP  102  being better-suited for the UE station  110  than the first WTP  102 , (d) in response to failure of the first WTP  102 , and (e) in response to the first WTP  102  being taken off-line for maintenance. However, wireless communication system  100  may be configured to hand-off a UE station  110  between two WTPs  102  for reasons other than the above-mentioned reasons. 
       FIGS. 4 and 5  each illustrate an example of hand-off of a UE station  110  for a reason other than movement of the UE station.  FIG. 4  is a block diagram illustrating an example of wireless communication system  100  handing-off  402  UE station  110 ( 2 ) from WTP  102 ( 4 ) to WTP  102 ( 5 ) in response to congestion at WTP  102 ( 4 ) exceeding a threshold value. The BSSID associated with UE station  110 ( 2 ) remains unchanged as wireless communication system  100  hands-off UE station  110 ( 2 ) between WTPs  102 ( 4 ) and  102 ( 5 ). Accordingly,  FIG. 4  illustrates WTP  102 ( 5 ) transmitting a Unicast beacon  114 ( 5 ), where Unicast beacon  114 ( 5 ) includes the same BSSID (BSSID 2) as Unicast beacon  114 ( 2 ). Consequentially, wireless communication system  100  appears to UE station  110 ( 2 ) as having a single WTP  102  that provides continuous coverage during the handoff from WTP  102 ( 4 ) to WTP  102 ( 5 ). Additionally, any individual wireless communication service associated with UE station  110 ( 2 ) may follow UE station  110 ( 2 ) during the hand-off from WTP  102 ( 4 ) to WTP  102 ( 5 ) because the BSSID associated with UE station  102 ( 2 ) does not change during the handoff. Wireless communication system  100  may perform other hand-offs of UE stations  110  between WTPs  102  managed by a common AC  104  in a manner similar to that illustrated in  FIG. 4 . 
       FIG. 5  is a block diagram illustrating wireless communication system  100  handing-off  502  UE station  110 ( 1 ) from WTP  102 ( 4 ) to WTP  102 ( 3 ) in response to congestion at AC  104 ( 2 ) exceeding a threshold value. WTP  102 ( 3 ) is managed by AC  104 ( 1 ) instead of by AC  104 ( 2 ), and handing-off UE station  110 ( 1 ) from WTP  102 ( 4 ) to WTP  102 ( 3 ) will therefore relieve congestion on AC  104 ( 2 ). 
     The BSSID associated with UE device  110 ( 1 ) remains unchanged as wireless communication system  100  hands-off UE station  110 ( 1 ) between WTPs  102 ( 4 ) and  102 ( 3 ). Accordingly,  FIG. 5  illustrates WTP  102 ( 3 ) transmitting a Unicast beacon  114 ( 6 ), where Unicast beacon  114 ( 6 ) includes the same BSSID (BSSID 1) as Unicast beacon  114 ( 1 ). Consequentially, wireless communication system  100  appears to UE station  110 ( 1 ) as having a single WTP  102  that provides continuous coverage during the handoff from WTP  102 ( 4 ) to WTP  102 ( 3 ). Additionally, any individual wireless communication service associated with UE station  110 ( 1 ) may follow UE station  110 ( 1 ) during the hand-off from WTP  102 ( 4 ) to WTP  102 ( 3 ) because the BSSID associated with UE station  110 ( 1 ) does not change during the handoff. Wireless communication system  100  may perform other hand-offs of UE stations  110  between WTPs  102  managed by different respective ACs  104  in a manner similar to that illustrated in  FIG. 5 . 
     Two or more WTPs  102  may operate on different respective wireless channels, such as to avoid RF interference between the WTPs  102 . Therefore, some embodiments of wireless communication system  100  are configured to include a channel switch announcement in a Unicast beacon  114  when handing off a UE station  110  between two WTPs  102  operating on different respective wireless channels. The channel switch announcement indicates to a receiving UE station  110  that a serving WTP is changing its operating wireless channel, and the UE station  110  therefore changes it operating channel in accordance with the channel switch announcement. The channel switch announcement may alternately or additionally indicate another change in wireless channel parameters, such as change in wireless channel width. 
     For example,  FIG. 6  is a block diagram illustrating an example of wireless communication system  100  handing-off UE station  110 ( 2 ) from WTP  102 ( 4 ) to WTP  102 ( 6 ), where WTP  102 ( 4 ) is operating on a first wireless channel (ch1) and WTP  102 ( 6 ) is operating on a second wireless channel (ch2). The  FIG. 6  handoff example is similar to the  FIG. 2  handoff example, except that Unicast beacon  114 ( 3 ) further includes a channel switch announcement (CSA) in the  FIG. 6  example. The CSA indicates to receiving UE station  110 ( 2 ) that a serving WTP is changing its wireless channel to ch2, and UE station  110 ( 2 ) therefore changes its operating wireless channel from ch1 to the ch2. Accordingly, including the CSA in Unicast beacon  114 ( 3 ) causes UE station  110 ( 2 ) to switch wireless channels in preparation for being served by WTP  102 ( 6 ). Inclusion of a channel switch announcement in a Unicast beacon  114  may also prevent the receiving UE station  110  from needing to scan all possible wireless channels for an available WTP signal, thereby helping conserve resources in wireless communication system  100 . The CSA may alternately or additionally indicate another change in wireless channel parameters. For example, the CSA could alternately indicate a change in channel width from 40 MHz to 80 MHz, or vice versa, thereby causing UE station  110  to switch wireless channel width in preparation for being served by WTP  102 ( 6 ). Wireless communication system  100  may be configured to include a channel switch announcement in Unicast beacons  114  in other handoff scenarios, such as those discussed above with respect to  FIGS. 3-5 . 
       FIG. 7  is a block diagram illustrating an AC  700 , which is one possible embodiment of AC  104 ( 2 ). ACs  104 ( 1 ),  104 ( 3 ), and  104 ( 4 ) could each also have a configuration similar to that illustrated in  FIG. 7 . It should be realized, however, that ACs  104  may be implemented in other manners without departing from the scope hereof. 
     AC  700  includes a processing subsystem  702  and a memory subsystem  704 . Processing subsystem  702  includes, for example, one or more processing devices (not shown) located at a single location or distributed among multiple locations, such as in multiple data centers. The one or more processing devices of processing subsystem  702  need not all have the same configuration. For example, processing subsystem  702  could include both microprocessors in a local server and processing resources in a cloud computing service. Memory subsystem  704  includes, for example, one or more memory devices (not shown) located at a single location or distributed among multiple locations. The one or more memory devices of memory subsystem  704  need not all have the same configuration. For example, memory subsystem  704  could include one or more solid-state memory modules and one or more magnetic data storage devices.  FIG. 7  illustrates AC  700  being logically connected to each of WTP  102 ( 4 ), WTP  102 ( 5 ), WTP  102 ( 6 ), and AAA server  106 , for consistency with the examples of  FIGS. 1-5 . However, the elements connected to AC  700  could vary without departing from the scope hereof. 
     Processing subsystem  702  is configured to execute instructions  706  stored in memory subsystem  704  to control at least some functions of AC  700 . Instructions  706  include, for example, software and/or firmware. In some embodiments, processing subsystem  702  executes instructions  706  to instantiate one or more of a Unicast beacon processor  708 , a WTP factor monitor  710 , a factor comparator  712 , a WTP selector  714 , an AC-AC hand-off module  716 , and an AC-AC communication module  718 . Processing subsystem  702  could be configured to execute instructions  706  to perform one or more additional functions and/or one or more alternative functions without departing from the scope hereof. 
     Unicast beacon processor  708  controls WTPs  102  to generate Unicast beacons  114 . AC  700  records received probe requests  112  as probe request data  720  stored in memory subsystem  704 , and receipt of a probe request from a given UE station  110  is used, for example, to trigger transmission of Unicast beacons  114  to the particular UE station  110 . Unicast beacon processor  708  determines which BSSID to include in a given Unicast beacon  114  from AAA data  726  stored in memory subsystem  704 . AAA data  726  associates a respective BSSID with each UE station  110  served by wireless communication system  100 . For example, AAA data  726  associates BSSID1 with UE device  110 ( 1 ), and AAA data  726  associates BSSID 2 with UE device  110 ( 2 ). As discussed above, BSSIDs may be static or dynamic. Basic service set (BSS) data  722  is also stored in memory subsystem  704 . 
     WTP factor monitor  710  monitors one or more factors of each WTP  102  managed by AC  700 , and WTP factor monitor  710  stores the monitored factors in memory subsystem  704  as WTP factor data  724 . For example,  FIG. 7  illustrates WTP factor data  724  including signal strength tables (SSTs) 1, 2, and 3. Each SST indicates RSSI of one or more UE stations  110  at a respective WTP  102 . Specifically, SST 1 indicates RSSI of one or more UE stations  110  at WTP  102 ( 4 ), SST 2 indicates RSSI of one or more UE stations  110  at WTP  102 ( 5 ), and SST 3 indicates RSSI of one or more UE stations  110  at WTP  102 ( 6 ). Each WTP  102  managed by AC  700  may generate and transmit its respective SST to AC  700 .  FIGS. 8-10  illustrate hypothetical examples of SST 1,  2 , and  3 , respectively. The example SST 1 of  FIG. 8  indicates that the RSSI of UE stations  110 ( 1 ) and  110 ( 2 ) is 9 and 6, respectively, at WTP  102 ( 4 ), and the example SST 2 of  FIG. 9  indicates that the RSSI of UE stations  110 ( 1 ) and  110 ( 2 ) is 5 and 7, respectively, at WTP  102 ( 5 ). The example SST 3 of  FIG. 10 , in turn, indicates that the RSSI of UE stations  110 ( 1 ) and  110 ( 2 ) is 2 and 3, respectively, at WTP  102 ( 6 ). 
     Factor comparator  712  compares WTP factor data  724 , and WTP selector  714  selects a serving WTP  102  for each UE station  110  based on the comparison performed by factor comparator  712 . For example, assuming that WTP factor data  724  includes the hypothetical SSTs of  FIGS. 8-10 , factor comparator  712  may compare RSSI of each SST to determine that WTP  102 ( 4 ) provides the highest RSSI for UE station  110 ( 1 ), and WTP selector  714  may therefore select WTP  102 ( 4 ) as the serving WTP for UE station  110 ( 1 ). Additionally, factor comparator  712  may compare RSSI of each SST to determine that WTP  102 ( 5 ) provides the highest RSSI for UE station  110 ( 2 ), and WTP selector  714  may therefore select WTP  102 ( 5 ) as the serving WTP for UE station  110 ( 2 ). However, AC  700  is not limited to selecting serving WTPs  102  based on RSSI. Instead, AC  700  may be configured to select serving WTPs  102  based on additional or alternative factors of WTPs  102 . For example, WTP factor data  724  could include one or more of the following alternative data in addition to, or in place, of SSTs 1-3: (a) congestion levels of WTPs  102 , (b) capacity of WTPs  102 , (c) operating status of WTPs  102 , (d) capabilities of WTPs  102 , and/or (e) number and/or type of UE stations  110  served by each managed WTP  102 . Factor comparator  712  may be configured to compare this alternative WTP factor data  724 , and WTP selector  714  may be configured to select a serving WTP based on the comparison of this alternative WTP factor data. 
     If WTP selector  714  selects a WTP  102  for a UE station  110  that is not the currently serving WTP for the UE station, AC  700  is configured to cause the UE station  110  to be handed-off to the selected WTP  102 . For example, assume that WTP  102 ( 4 ) is currently the serving WTP for UE station  110 ( 2 ), and WTP selector  714  selects WTP  102 ( 5 ) as the serving WTP. AC  700  would then cause UE station  110 ( 2 ) to be handed-off from WTP  102 ( 4 ) to WTP  102 ( 5 ). 
     In some embodiments, AC  700  is configured to cooperate with one or more other ACs  104  to coordinate handoff of a UE station  110  from a WTP  102  managed by AC  700  to a WTP  102  managed by another AC  104 . Accordingly, in some embodiments, WTP factor data  724  includes factor data for WTPs  102  other than those managed by AC  700 . For example, WTP factor data  724  may include SSTs for WTPs managed by adjacent ACs  104 ( 1 ) and  104 ( 3 ), and in these embodiments, each WTP  102  may transmit a respective SST to adjacent ACs  104  as well as to its managing AC  104 . 
     AC-AC hand-off module  716  and AC-AC communication module  718  facilitate handoff of a UE station  110  between WTPs  102  managed by different respective ACs  104 . AC-AC communication module  718  enables AC  700  to communicate with another AC  104  to coordinate a handoff, such as to communicate output of WTP selector  714  to another AC  104 . AC-AC hand-off module  716  enables AC  700  to implement a handoff of a UE device to a WTP  102  managed by another AC  104 . 
     Referring again to  FIG. 1 , in some embodiments, ACs  104  are configured to support a make-before-break handoff of a UE station  110  between two WTPs  102 . A make-before-break handoff is characterized by an AC  104  establishing data flow between an UE station  110  and a destination WTP  102  before terminating data flow between the UE station  110  and a source WTP  102 . A make-before-break handoff advantageously prevents interruption of data flow during the handoff. 
       FIG. 11  is a dataflow diagram illustrating one example of a make-before-break handoff of a UE station  110  between two WTPs  102  and  102 ′ managed by a common AC  104 , in wireless communication system  100 . In  FIG. 11 , an AC  104  supports a handoff of a UE station  110  from a source WTP  102  to a destination WTP  102 ′. The AC  104  optionally transmits an Add Station command  1102  to the source WTP  102 , and the source WTP  102  responds with an acknowledgement  1104 . The Add Station command  1102  shows the point at which the UE station  110  became associated with the source WTP  102 . At a later point where the AC  104  initiates a hand-off of the UE station  110  from the source WTP  102  to the destination WTP  102 ′, the AC  104  transmits an Add WLAN (wireless local area network) command  1106  to the destination WTP  102 ′, and the destination WTP  102 ′ responds with an acknowledgement  1108 . After a WLAN has been added to the destination WTP  102 ′, the AC  104  transmits an Add Station command  1110  to the destination WTP  102 ′, and the destination WTP  102 ′ responds with an acknowledgement  1112 . 
     The UE station  110  is accordingly now being served by the destination WTP  102 ′, and a data stream  1114  consequently flows between the UE station  110  and the AC  104  via the destination WTP  102 ′. The AC  104  waits for data stream  1114  to be established before beginning to break the connection between the source WTP  102  and the UE station  110  by transmitting a Remove Station command  1116  to the source WTP  102 . The source WTP  102  responds with an acknowledgement  1118 . The AC  104  optionally then transmits a Remove WLAN command  1120  to the source WTP  102 , and the source WTP responds with an acknowledgement  1122 . In some other embodiments, a Remove WLAN command is incorporated with Remove Station command  1116  instead of being sent as a discrete command. The make-before-break handoff is then concluded. 
     Both the source WTP  102  and the destination WTP  102 ′ may simultaneously own the address of the UE station  110  during the make-before-break handoff, which may be problematic in certain circumstances. For example, both the source WTP  102  and the destination WTP  102 ′ may respond to receipt of a data frame from the UE station  110  by transmitting an acknowledgement message, without first performing a clear-channel-assessment (CCA). Consequently, the respective acknowledgement messages from the source WTP  102  and the destination WTP  102 ′ may collide, preventing the UE station  110  from receiving an acknowledgement message from either WTP  102 . 
     Accordingly, in some embodiments, wireless communication system  100  is configured to reduce transmit power of the source WTP  102  during a make-before-break handoff, but only for data frames addressed to the UE station  110  being handed-off. This reduction in transmit power of the source WTP  102  helps prevent significant collisions between acknowledgement messages from the source WTP  102  and the destination WTP  102 ′ at the UE station  110  being handed-off. Alternately or additionally, transmit power of the destination WTP  102 ′ could be increased during the make-before-break handoff, for data frames addressed to the UE station  110  being handed off. Transmit power of the source WTP  102  and/or the destination WTP  102 ′ during a make-before-break hand-off is controlled, for example, by one or more managing ACs  104  and/or by the source and destination WTPs themselves. 
       FIG. 12  is a graph  1200  illustrating one example of how the source WTP  102  may reduce transmit power during a make-before-break handoff of a UE station  110 , for data frames addressed to the UE station  110 . The horizontal axis of graph  1200  represents distance, and the vertical axis of graph  1200  represents RSSI magnitude. In this example, the source WTP  102  is located at position A and has a RSSI magnitude  1202  as a function of distance from the WTP, and the destination WTP  102 ′ is located at position B and has a RSSI magnitude  1204  as a function of distance from the WTP  102 ′. It should be noted that although RSSI magnitudes  1202  and  1204  are shown as monotonic curves in graph  1200  for illustrative simplicity, the actual shapes of RSSI magnitude curves may vary significantly depending on operating environment. 
     Assume that the UE device  110  being hand-off is located as position C. Although position C is closer to the destination WTP  102 ′ than to the source WTP  102 , RSSI  1202  of the source WTP is still relatively high at position C, i.e. about 2.0. Consequently, simultaneously transmission of acknowledgment messages by both the source and destination WTPs  102  and  102 ′ would result in a significant RF signal collision at point C, if the source WTP  102  did not reduce it transmit power. However, in this example, the source WTP  102  reduces its transmit power during a make-before-break handoff of a UE station  110 , such that data frames addressed to the UE station  110  being handed-off have an associated RSSI magnitude  1206  as a function of distance. As evident from  FIG. 12 , RSSI magnitude  1206  is negligible at position C, such that simultaneously transmission of acknowledgment messages by both the source and destination WTPs  102  and  102 ′ results in negligible RF signal collision at the UE station  110  at position C. 
       FIGS. 13-16 , discussed below, illustrate some possible operating methods of wireless communication system  100 . However, wireless communication system  100  is not limited to these operating methods. Additionally, the methods of  FIGS. 13-16  are not limited to use with wireless communication system  100 . 
       FIG. 13  is a flow chart illustrating a method  1300  for providing continuous wireless communication service. In a block  1302 , a first Unicast beacon is transmitted from a first WTP to a first UE station. In one example of block  1302 , WTP  102 ( 4 ) transmits Unicast beacon  114 ( 2 ) to UE station  110 ( 2 ). [ FIG. 2 .] In another example of block  1302 , WTP  102 ( 4 ) transmits Unicast beacon  114 ( 1 ) to UE station  110 ( 1 ). [ FIG. 5 ]. In a block  1304 , the first UE station is handed off from the first WTP to a second WTP, after transmitting the first Unicast beacon to the first UE station. In one example of block  1304 , AC  104 ( 2 ) controls WTPs  102 ( 4 ) and  102 ( 6 ) to handoff UE station  110 ( 2 ) from WTP  102 ( 4 ) to WTP  102 ( 6 ). [ FIG. 2 .] In another example of block  1304 , ACs  104 ( 2 ) and  104 ( 1 ) cooperate to control WTPs  102 ( 4 ) and  102 ( 3 ) to handoff UE station  110 ( 1 ) from WTP  102 ( 4 ) to WTP  102 ( 3 ). 
     In a block  1306 , a second Unicast beacon is transmitted from the second WTP to the first UE station, where each of the first and second Unicast beacons includes a common first BSSID. In one example of block  1306 , WTP  102 ( 6 ) transmits Unicast beacon  114 ( 3 ) to UE station  110 ( 2 ), where each of Unicast beacons  114 ( 2 ) and  114 ( 3 ) includes common BSSID 2. [ FIG. 2 .] In another example of block  1306 , WTP  102 ( 3 ) transmits Unicast beacon  114 ( 6 ) to UE station  110 ( 1 ), where each of Unicast beacons  114 ( 1 ) and  114 ( 6 ) includes common BSSID 1. 
       FIG. 14  is a flow chart illustrating a method  1400  for authenticating and associating a UE station. In a block  1402 , a UE station transmits a probe request. In one example of block  1402 , UE device  110 ( 1 ) transmits a probe request  112 ( 1 ) to WTPs  102 ( 4 ) in its vicinity. [ FIG. 1 .] In a block  1404 , a plurality of WTPs receive the probe request. In one example of block  1404 , probe request  112 ( 1 ) is received by each of WTPs  102 ( 2 )- 102 ( 6 ). In a block  1406 , an AC sends UE station data, e.g. a MAC address of the UE station, to an AAA server to authenticate the UE station. In one example of block  1406 , AC  104 ( 2 ) sends UE station  110 ( 1 ) data to AAA server  106  via an authorization message to authenticate UE station  110 ( 1 ) in wireless communication system  100 . 
     A decision block  1408  determines whether authentication is successful. If no, method  1400  ends, and if yes, method  1400  proceeds to a block  1410 . In one example of decision block  1408 , AAA server  106  determines whether authentication of UE station  110 ( 1 ) was successful. In block  1410 , the AAA server sends an authorization ok message to the AC, where the authorization ok message includes a SSID and a BSSID, in response to successful authentication of the UE device. In one example of block  1410 , AAA  106  sends an authentication ok message to AC  104 ( 2 ), wherein the authentication message includes a SSID and BSSID 1 associated with UE station  110 ( 1 ). 
     In a block  1412 , the AC monitors factors to determine WTP selection. In one example of block  1412 , WTP factor monitor  710  monitors WTP  102  factors and stores the factors as WTP factor data  724 . [ FIG. 7 ]. In a block  1414 , the AC compares WTP factors, such as RSSI data, to select a best WTP. In one example of block  1414 , factor comparator  712  compares RSSI data from SSTs 1-3 stored in WTP factor data  724 . In a block  1416 , the AC selects the best WTP for the UE station based on the factor comparison of block  1414 . In one example of block  1416 , WTP selector  714  selects WTP  102 ( 4 ) as being the best WTP  102  for UE station  110 ( 1 ) in response to factor comparator  712  determining from SSTs 1-3 that WTP  102 ( 4 ) has the highest RSSI for UE station  110 ( 1 ). In a block  1418 , the AC instructs the WTP selected in block  1416  to transmit Unicast beacons, including SSID and BSSID, to the UE. In one example of block  1418 , AC  104 ( 2 ) instructs WTP  102 ( 4 ) to begin transmission of Unicast beacons  114 ( 1 ) to UE station  110 ( 1 ), where Unicast beacons  114 ( 1 ) includes an SSID and BSSID 1. 
     A decision block  1420  determines whether the UE has station moved. If no, method  1400  proceeds to a decision block  1422 , and if yes, method  1400  returns to block  1414  to again compare WTP factors. In one example of decision block  1420 , AC  104 ( 2 ) and/or WTP  102 ( 4 ) determine whether UE station  110 ( 1 ) has moved by determining if RSSI data for UE station  110 ( 1 ) has changed by more than a threshold value, which indicates movement of UE station  110 ( 1 ). A decision block  1422  determines whether the UE station has sent an association request to the WTP selected in block  1416 . If no, method  1400  returns to block  1414  to again compare WTP factors, and if yes, method  1400  proceeds to a block  1424 . In one example of decision block  1422 , AC  104 ( 2 ) determines whether it has received an association request from UE station  110 ( 1 ). In block  1424 , the WTP sends the association request to the AC, and in one example of block  1424 , WTP  102 ( 4 ) forwards an association request received from UE device  110 ( 1 ) to AC  104 ( 2 ). In a block  1426 , the AC sends the association request to the AAA server via an authorization message, and in one example of block  1426 , AC  104 ( 2 ) forwards the association request received from WTP  102 ( 4 ) to AAA server  106 . 
     In a block  1428 , the AAA server sends an association okay message to the AC, and the AAA server also sends a security certificate to the AC if the certificate was not previously sent. In one example of block  1428 , AAA server  106  sends an association okay message to AC  104 ( 2 ). In a block  1430 , the AC sends the association ok message, along with basic service set (BSS) information, to the WTP selected in block  1416 . In one example of block  1430 , AC  104 ( 2 ) forwards the association ok message received from AAA server  106 , along with BSS information, to WTP  102 ( 4 ). In an optional block  1432 , the AC sends a delete UE data message to any previously selected WTP. In one example of block  1432 , AC  104 ( 2 ) transmits a delete UE message to any WTP  102  selected before WTP  102 ( 4 ). In a block  1434 , the WTP associates with the UE station. In one example of block  1434 , WTP  102 ( 4 ) associates with UE station  110 ( 1 ). 
     In some alternate embodiments, association is locally handled by an AC  104 , and blocks  1426  and  1428  are therefore omitted. For example, in an alternate embodiment, AC  104 ( 2 ) sends an association okay message to WTP  102 ( 4 ) in response to receiving an association request from WTP  102 ( 4 ). 
       FIG. 15  is a flow chart illustrating a method  1500  for associating a user equipment station, according an embodiment. In a block  1502 , a UE station sends an association request to a WTP. In one example of block  1502 , UE station  110 ( 1 ) sends an association request to WTP  102 ( 4 ). [ FIG. 1 .] In a block  1504 , the WTP sends the association request to the AC. In one example of block  1504 , WTP  102 ( 4 ) forwards an association request received from UE station  110 ( 1 ) to AC  104 ( 2 ). In a block  1506 , the AC sends the association request to an AAA server. In one example of block  1506 , AC  104 ( 2 ) forwards the association request received from WTP  102 ( 4 ) to AAA server  106 . 
     In a block  1508 , the AAA server sends an association grant (AG) to the AC. In one example of block  1508 , AAA server  106  sends an association grant to AC  104 ( 2 ). In an optional block  1510 , the AAA server optionally sends a security certificate with a BSS to the AC if the certificate was not previously sent. In one example of block  1510 , AAA server  106  sends a security certificate and a BSS to AC  104 ( 2 ). In a block  1512 , the AC sends the association grant to the WTP. In one example of block  1512 , AC  104 ( 2 ) forwards the association grant received from AAA server  106  to WTP  102 ( 4 ). In a block  1514 , the WTP sends the association grant to the UE station. In one example of block  1514 , WTP  102 ( 4 ) forwards the association grant received from AC  104 ( 2 ) to UE station  110 ( 1 ). In a block  1516 , the UE station associates with the WTP. In one example of block  1516 , UE station  110 ( 1 ) associates with WTP  102 ( 4 ). 
     In some alternate embodiments, the AC handles UE station association without assistance from an AAA server. Accordingly, in an alternate embodiment, blocks  1506 - 1510  are omitted, and the AC sends an AG to the WTP in response to receiving an association request from the WTP. 
       FIG. 16  is a flow chart illustrating a method  1600  for handing off a UE station. In a block  1602 , an AC detects a UE station moving from a first WTP to a second WTP. In one example of block  1602 , AC  104 ( 2 ) detects UE station  110 ( 2 ) moving from WTP  102 ( 4 ) to WTP  102 ( 6 ), such as illustrated in  FIG. 2 . In a decision block  1604 , the AC determines whether authentication of the UE station at the second WTP was successful. If yes, method  1600  proceeds to a block  1606 , and if no, method  1600  proceeds to a block  1608 . In one example of decision block  1604 , AC  104 ( 2 ) determines from AAA server  106  whether authentication of UE station  110 ( 2 ) at WTP  102 ( 6 ) was successful. In block  1606 , the UE station is handed-off from the first WTP to the second WTP using a normal procedure, e.g. without switching wireless channels used by the UE station or other wireless parameters associated with the UE station. In some alternate embodiments, blocks  1604  and  1606  are omitted, and method  1600  proceeds from block  1602  to block  1608 . 
     In block  1608 , a data collection modeling process is performed, such as using techniques disclosed in one or more of U.S. Patent Application No. 62/558,933 or U.S. Patent Application Pre-Grant Publication No. 2019/0075469, to determine an optimum channel for the UE station. In one example of block  1608 , AC  104 ( 2 ) uses the techniques disclosed in one or more of the aforementioned U.S. patent documents to determine an optimum wireless channel for UE station  110 ( 2 ). In a block  1610 , the AC creates the same BSSID on the second WTP, in accordance with the channel determined in block  1608 . In one example of block  1610 , AC  104 ( 2 ) creates BSSID 2 on WTP  102 ( 6 ). In a block  1612 , the second WTP uses a channel switch announcement to migrate the UE station to the channel determined in block  1608 , and the AC starts a make-before-break handoff process, such as discussed above with respect to  FIG. 11 . In one example of block  1612 , WTP  102 ( 6 ) includes a channel switch announcement in a Unicast beacon  114  transmitted from WTP  102 ( 6 ) to UE device  110 ( 2 ), such as illustrated in  FIG. 6 . In a block  1614 , the AC deletes the BSS on the first WTP. In one example of block  1614 , AC  104 ( 2 ) deletes the BSS on WTP  102 ( 4 ). 
     In some alternate embodiments of wireless communication system  100 , at least one WTP  102  is managed by two or more ACs  104 , to facilitate handoff of UE stations  110  between WTPs  102  managed by different respective ACs  104 . For example,  FIG. 17  is a block diagram of a wireless communication system  1700 , which is an alternate embodiment of wireless communication system  100  where several WTPs  102  are managed by a plurality of ACs  104 . A service area of wireless communication system  1700  is divided into four regions, namely Region A, Region B, Region C, and Region D. Region A includes WTPs  102 ( 1 )- 102 ( 3 ), Region B includes WTPs  102 ( 4 )- 102 ( 6 ), Region C includes WTPs  102 ( 7 )- 102 ( 9 ), and Region D includes WTPs  102 ( 10 )- 102 ( 12 ). The number of regions in wireless communication system  1700 , the number WTPs  102  in each region, and the identities of WTPs  102  in each region, may vary without departing from the scope hereof. 
     The WTPs  102  of each region are associated with a primary AC  104 , and logical connections between a WTP  102  and its primary AC are denoted by a solid line  1702 . AC  104 ( 1 ) is the primary AC for region A, AC  104 ( 2 ) is the primary AC for Region B, AC  104 ( 3 ) is the primary AC for region C, and AC  104 ( 4 ) is the primary AC for region D. Additionally, WTPs  102  adjacent to a neighboring region are associated with a secondary AC  104 , which is the primary AC  104  of the neighboring region. Logical connections between a WTP  102  and its secondary AC  104  are denoted by dashed lines  1704 . AC  104 ( 1 ) is a secondary AC to each of WTPs  102 ( 4 ) and  102 ( 12 ), AC  104 ( 2 ) is a secondary AC to each of WTPs  102 ( 3 ) and  102 ( 7 ), AC  104 ( 3 ) is a secondary AC to each of WTPs  102 ( 6 ) and  102 ( 10 ), and AC  104 ( 4 ) is a secondary AC to each of WTPs  102 ( 1 ) and  102 ( 9 ). WTPs  102 ( 2 ),  102 ( 5 ),  102 ( 8 ), and  102 ( 11 ) are not associated with a secondary AC  104  because these WTPs are not adjacent to a neighboring region. In some alternate embodiments of wireless communication system  1700 , one or more WTPs  102  are associated with two or more secondary ACs  104 , such as when the WTP  102  is adjacent to two or more neighboring regions. 
     A primary AC  104  of a region coordinates a handoff of a UE station into the AC&#39;s region. As an example, consider an example scenario where (a) a UE station  110 ( 3 ) is being served by WTP  102 ( 4 ) in region B and (b) AC  104 ( 2 ) is managing UE station  110 ( 3 ). Now assume that UE station  110 ( 3 ) is moving away from WTP  102 ( 4 ) and towards WTP  102 ( 3 ), as indicated by an arrow  1706 . Accordingly, UE station  110 ( 3 ) will be handed-off from WTP  102 ( 4 ) to WTP  102 ( 3 ). AC  104 ( 1 ) is the primary AC associated with WTP  102 ( 3 ), so AC  104 ( 1 ) makes itself, instead of AC  104 ( 2 ), the manager of UE station  110 ( 3 ), such as using the techniques discussed below with respect to  FIG. 18 . AC  104 ( 1 ) can make itself the manager of UE station  110 ( 3 ) while the UE station is being served by WTP  102 ( 4 ) because AC  104 ( 1 ) is a secondary AC for WTP  102 ( 4 ), as well as the primary AC for WTP  102 ( 3 ). AC  104 ( 1 ) then initiates and coordinates the handoff of UE station  110 ( 3 ) from WTP  102 ( 4 ) to WTP  102 ( 3 ). In some embodiments, each WTP  102  transmits a respective SST to both the primary and secondary AC  104  associated with the WTP, to enable either of the ACs  104  to initiate a handoff of a UE station  110  served by the WTP. 
     It is possible that multiple WTPs  102  on multiple ACs  104  will respond to a probe request when a UE station  110  first comes online. Accordingly, in some embodiments, wireless communication system  1700  is configured so that the UE station  110  is authenticated and associated with whichever WTP  102  that is selected by the UE station  110 . The UE station  110  can subsequently be handed-off to a different WTP  102 , is needed. 
       FIG. 18  is a dataflow diagram illustrating one example of transitioning ACs  104  managing a UE station  110  during a handoff of the UE station  110 . The transition begins with a destination AC  104 ′ transmitting an Add Station command  1802  to a source WTP  102 , and the source WTP  102  responds with an acknowledgement  1804 . The source WTP  102  determines that the UE station  110  has already established a connection with the source AC  104 , and the source WTP  102  therefore interprets the Add Station command  1802  as a request to change managing AC  104  for the UE station  110 . The source WTP  102  accordingly immediately begins to transmit data to the destination AC  104 ′, and the source WTP  102  also locks itself so that no other AC  104  can initiate a handoff. The source WTP  102  transmits a Disassociate WLAN command  1806  to the source AC  104 , and the source AC  104  responds with an acknowledgement  1808 . The source AC  104  responds by transmitting a Remove Station command  1810  to the source WTP  102 , and the source WTP  102  responds with an acknowledgement  1812 . The source AC  104  also transmits a Remove WLAN command  1814  to the source WTP  102 , and the source WTP  102  responds with an acknowledgement  1816 . A data stream  1818  between the source WTP  102  and destination AC  104 ′ is established, and the destination AC  104 ′ is now the manager of the UE station  110 . The handoff continues, for example, using the techniques discussed above with respect to  FIG. 11 . 
     Although there are significant advantages to beacons  114  being Unicast beacons, as discussed above, there may be applications where it would be beneficial for beacons  114  to be MultiCast beacons, such in cases where two associated UE stations move together. Accordingly, in some alternate embodiments, beacons  114  are MultiCast beacons, instead of Unicast beacons. 
     Customized Wireless Communication Beacons 
     Transmitting Unicast beacons, instead of Broadcast beacons, may achieve significant advantages, as discussed above. However, transmitting Unicast beacons may incur significant overhead that limits wireless communication system scalability. 
     In particular, a WTP conventionally transmits a beacon in a manner which helps maximize likelihood and speed of UE stations detecting the beacon. For example, the WTP transmits the beacon at a high-power-level, to enable distant UE stations to detect the beacon. Additionally, the WTP transmits the beacon using a lowest-supported modulation mode, to promote robust beacon transmission and to achieve backward compatibility with legacy UE stations. Furthermore, the WTP transmits the beacon at a relatively high transmission rate, to promote quick detection of the beacon by a UE station. 
     While conventional beacon transmission techniques help maximize likelihood and speed of beacon detection, they also consume significant wireless communication system resources. For example, transmitting a beacon at a low modulation mode, as well as transmitting a beacon at a high transmission rate, requires significant wireless communication system airtime. For instance, Applicant has determined that Broadcast beacon transmission in a conventional Wi-Fi wireless communication system requires approximately 2.64% of wireless communication system airtime for each network, i.e. for each SSID/BSSID pair. Furthermore, transmitting a beacon at a high-power-level consumes wireless communication system airtime over a large physical area. 
     There is a respective wireless communication network for each UE station in a wireless communication network transmitting Unicast beacons. Therefore, transmitting Unicast beacons, instead of Broadcast beacons, may significantly increase beacon overhead because a separate beacon transmission is required for each UE station. Accordingly, wireless communication system overhead associated with Unicast beacon transmission increases approximately linearly with each additional UE station. Indeed, Applicant estimates that Unicast beacon transmission consumes about 100% of available airtime when supporting approximately 40 UE stations on a given channel in a wireless communication system. 
     Disclosed herein systems and methods for customizing wireless communication beacons, which may mitigate the above-discussed problems. The new system and methods leverage the fact that it is not necessary for a Unicast beacon be detected by a plurality of UE stations; instead, a Unicast beacon merely needs to be detected by a UE station that the beacon is addressed to. Accordingly, the beacon can be customized according to one or more characteristics of the UE station to help minimize overhead associated with the beacon&#39;s transmission, while ensuring that the beacon is detected by its intended recipient UE station. Additionally, Applicant has developed wireless communication systems and methods which help minimize overhead associated with wireless beacon transmission by concurrently transmitting a beacon with one or more additional data frames. 
       FIG. 19  is a block diagram illustrating a wireless communication system  1900  configured to customize wireless communication beacons. System  1900  includes a WTP  1902 , a UE station  1904 , and a UE station  1906 . System  1900  could be modified to include a different number of WTPs and/or a different number of UE stations without departing from the scope hereof. 
     WTP  1902  is configured to convert electrical or optical signals to wireless signals, and vice versa, to enable one or more UE stations, such as UE stations  1904  and  1906 , to wirelessly communicate with a core network (not shown) communicatively coupled to WTP  1902 . In some embodiments, WTP  1902  operates according to a Wi-Fi-based standard or other IEEE 802.11-based standard. UE stations  1904  and  1906  communicate with WTP  1902  using RF signals. Each of UE stations  1904  and  1906  is, for example, a mobile telephone, a computer, a set-top device, a data storage device, an Internet of Things (IoT) device, an entertainment device, a wireless access point (including, for example, eNBs, gNBs, and Wi-Fi APS acting as UEs), a computer networking device, a smartwatch, a wearable device with wireless capability, or a medical device. UE stations  1904  and  1906  are not necessarily part of wireless communication system  1900 . In some embodiments, UE stations  1904  and  1906  are conventional UE stations, i.e. UE stations  1904  and  1906  are not specially adapted for use in wireless communication system  1900 . 
     WTP  1902  is configured to transmit both default beacons and custom beacons. Default beacons have a standard configuration for wireless communication system  1900 , and custom beacons have one or more attributes that are customized for an intended recipient UE station. In some embodiments, WTP  1902  is configured to determine one or more characteristics of a UE station  1904  or  1906  from a message, such as an acknowledgement message, received from the UE station, and WTP  1902  is configured to customize beacons for the UE station according to the one or more characteristics. WTP  1902  customizes the beacons, for example, to help minimize airtime in wireless communication system  1900  that is used for beacon transmission. 
     For example, in some embodiments, WTP  1902  is configured to execute a method  2000 , illustrated in  FIG. 20 , for customizing wireless communication beacons. In a block  2002  of method  2000 , WTP  1902  transmits a first Unicast beacon to a UE station. In one example of block  2002 , WTP  1902  transmits a default Unicast beacon  1908  to UE station  1904 , and in another example of block  2002 , WTP  1902  transmits a default Unicast beacon  1910  to UE station  1906 . Default Unicast beacons  1908  and  1910  have a standard configuration for system  1900 , i.e. default Unicast beacons  1908  and  1910  are not customized for their respective UE stations. In some embodiments, default Unicast beacons  1908  and  1910  are Wi-Fi-based beacons. It should be understood that the term “first” in block  2002  need not require that WTP  1902  transmit no other beacons before transmitting the first Unicast beacon. Instead, the term “first” is used to distinguish the beacon transmitted in block  2002  from other beacons referenced in method  2000 . 
     In a block  2004  of method  2000 , WTP  1902  receives an acknowledgement data frame from the UE station. In one example of block  2004 , WTP  1902  receives an acknowledgment data frame  1912  from UE station  1904 , and in another example of block  2004 , WTP  1902  receives an acknowledgment data frame  1914  from UE station  1906 . UE station  1904  transmits acknowledgement data frame  1912  in response to successfully receiving default Unicast beacon  1908 , and UE station  1906  transmits acknowledgement data frame  1914  in response to successfully receiving default Unicast beacon  1910 . 
     In a block  2006  of method  2000 , WTP  1902  determines one or more characteristics of the UE station from the acknowledgement data frame. Each of the one or more characteristics of the UE station is either a static characteristic or a dynamic characteristic. In one example of block  2006 , WTP  1902  determines one or more characteristics of UE Station  1904  from acknowledgement data frame  1912 , and in another example of block  2006 , WTP  1902  determines one or more characteristics of UE station  1906  from acknowledgement data frame  1914 . Examples of possible UE device characteristics that WTP  1902  may determine from an acknowledgment data frame include, but are not limited to, (a) received signal strength of the acknowledgement data frame, (b) distance of the UE station from WTP  1902 , (b) modulation mode supported by the UE station, (c) data rate supported by the UE station, (d) guard interval required by the UE station, and (e) identity of the UE station, e.g. MAC address of the UE station. In some alternate embodiments, WTP  1902  determines one or more characteristics of the UE station from one or more data frames received in addition to the acknowledgement data frame received in block  2004 . In other alternate embodiments, WTP  1902  does not require an acknowledgement data frame to determine one or more characteristics of the UE station; instead, WTP  1902  determines one or more characteristics of the UE station from one or more other data frames. 
     In a block  2008  of method  2000 , WTP  1902  customizes one or more second Unicast beacons for the UE station, based at least in part on the one or more characteristics of the UE station determined in block  2006 . WTP  1902  customizes the second Unicast beacons, for example, to help minimize airtime required to transmit the second Unicast beacons in wireless communication system  1900 . The following are several examples of how WTP  1902  can be configured to customize the second Unicast beacons. However, WTP  1902  could be configured to customize the second Unicast beacons in one or more alternative and/or additional manners without departing the scope hereof. 
     A. Custom Modulation Mode 
     In some embodiments, WTP  1902  is configured to customize the one or more second Unicast beacons by selecting a modulation mode of the second Unicast beacons, based at least in part on the one or more characteristics of the UE station determined in block  2006 . For example, in certain embodiments, WTP  1902  determines a highest-order modulation mode that can be handled by the UE station from the one or more characteristics determined in block  2006 , and WTP  1902  selects the modulation mode of the second Unicast beacons accordingly. Use of a high-order modulation mode to transmit the second Unicast beacons advantageously helps minimize airtime required to transmit the second Unicast beacon to the UE station. 
     B. Custom Transmission Power 
     In some embodiments, WTP  1902  is configured to customize the one or more second Unicast beacons by selecting a transmission power of the second Unicast beacons, based at least in part on the one or more characteristics of the UE station determined in block  2006 . For example, in certain embodiments, WTP  1902  determines a lowest transmission power that enables successful transmission of the second Unicast beacons to the UE station, such as based on received signal strength of the acknowledgement data frame received in block  2004 . Minimizing transmission power of the second Unicast beacons advantageously helps reduce a “footprint” of the second Unicast beacons, or in other words, helps minimize extent of airspace affected by transmission of the second Unicast beacons. In other embodiments, however, WTP  1902  determines a maximum acceptable transmission power of the second Unicast beacons, to help enable transmission of the second Unicast beacons at a high data rate. 
     C. Custom Data Rate 
     In some embodiments, WTP  1902  is configured to customize the one or more second Unicast beacons by selecting a data rate of the second Unicast beacons, based at least in part on the one or more characteristics of the first UE station determined in block  2006 . For example, in certain embodiments, WTP  1902  determines a highest data rate that can be handled by the UE station from the one or more characteristics determined in block  2006 , and WTP  1902  selects the data rate of the second Unicast beacons accordingly. Use of a high data rate to transmit the second Unicast beacons advantageously helps minimize airtime required to transmit the second Unicast beacon to the UE station. 
     D. Custom Repetition Rate 
     In some embodiments, WTP  1902  is configured to customize the one or more second Unicast beacons by selecting a repetition rate of the second Unicast beacons, based at least in part on the one or more characteristics of the UE station determined in block  2006 . For example, in certain embodiments, WTP  1902  determines a lowest repetition rate that will maintain a connection with the UE station, such as based on an identity of the UE station, as minimum required repetition rate may vary among UE stations. Minimizing Unicast beacon repetition rate advantageously helps minimize airtime required to transmit second Unicast beacons to the UE station. 
     E. Custom Transmission Direction 
     In some embodiments, WTP  1902  is configured to customize the one or more second Unicast beacons by selecting a transmission direction of the second Unicast beacons, based at least in part on the one or more characteristics of the UE station determined in block  2006 . For example, in certain embodiments, WTP  1902  determines a direction of the UE station from WTP  1902  based on direction of the acknowledgement data frame received in block  2004 , and WTP  1902  selects a transmission direction of the second Unicast beacons such that the beacons are transmitted toward the UE station. Transmission of second Unicast beacons toward an intended recipient UE station, instead of transmitting Unicast beacons in an omnidirectional manner, helps minimize extent of airspace affected by transmission of the second Unicast beacons. WTP  1902  controls the transmission direction of the second Unicast beacons, for example, using beamforming techniques. 
     F. Custom Payload 
     In some embodiments, WTP  1902  is configured to customize the one or more second Unicast beacons by selecting a payload of the beacons, based at least in part on the one or more characteristics of the UE station determined in block  2006 . For example, in certain embodiments, WTP  1902  determines a minimum payload that must be included in the second Unicast beacons to maintain a connection with the UE station, such as based on an identity of the UE station and/or operating state of the UE station. For instance, in some embodiments where WTP  1902  operates according to a Wi-Fi standard, WTP  1902  may determine that Wi-Fi Protected Setup (WPS) data elements are not required in the second Unicast beacons, and WTP  1902  may therefore omit WPS data elements from the second Unicast beacons. Minimizing Unicast beacon payload advantageously helps minimize airtime required to transmit the second Unicast beacons to the UE station. 
     G. Custom Multiple-Input and Multiple Output Order 
     In some embodiments, WTP  1902  is configured to customize the one or more second Unicast beacons by selecting a multiple-input and multiple-output (MIMO) transmission order of the second Unicast beacons based at least in part on the one or more characteristics of the first UE station determined in block  2006 . For example, in certain embodiments, WTP  1902  determines a highest MIMO transmission order, e.g. 2×2, 3×3, or greater, that can be handled by the UE station from the one or more characteristics determined in block  2006 , and WTP  1902  selects the MIMO transmission order of the second Unicast beacons accordingly. Use of a high MIMO transmission order to transmit the second Unicast beacons advantageously helps minimize airtime required to transmit the Unicast beacons to the UE station. 
     H. Custom Guard Interval 
     In some embodiments, WTP  1902  is configured to customize the one or more second Unicast beacons by selecting a guard interval of the second Unicast beacons, based at least in part on the one or more characteristics of the UE station determined in block  2006 . For example, in certain embodiments, WTP  1902  determines a shortest guard interval that enables successful transmission of the second Unicast beacons to the UE station, from the one or more characteristics determined in block  2006 . Minimizing Unicast beacon guard interval advantageously helps minimize airtime required to transmit second Unicast beacons to the UE station. 
     I. Channel Width 
     In some embodiments, WTP  1902  is configured to customize the one or more second Unicast beacons by selecting a channel width of the second Unicast beacons, based at least in part on the one or more characteristics of the first UE station determined in block  2006 . For example, in certain embodiments, WTP  1902  determines a highest channel width, e.g. 20 MHz, 40 MHz, 80 MHz, 160 MHz, or greater, that can be handled by the UE station from the one or more characteristics determined in block  2006 , and WTP  1902  selects the channel width of the second Unicast beacons accordingly. Use of a high channel width to transmit the second Unicast beacons advantageously helps minimize airtime required to transmit the Unicast beacon to the UE station 
     In some embodiments, WTP  1902  determines one or more appropriate customizations of the second Unicast beacons directly from the one or more characteristics of the UE station determined in block  2006 . For example, in certain embodiments where maximum supported modulation mode and/or data rate of the UE station are determined in block  2006 , WTP  1902  determines that second Unicast beacons should be customized to have corresponding modulation mode and/or data rate. As another example, in certain embodiments where WTP  1902  determines in block  2006  a direction of the UE station from WTP  1902 , WTP  1902  determines that second Unicast beacons should be customized to have a transmission direction corresponding to the direction determined in block  2006 . 
     In some embodiments, WTP  1902  determines one or more appropriate customizations of the second Unicast beacons indirectly from the one or more characteristics of the UE station determined in block  2006 . For example, in certain embodiments, WTP  1902  determines in block  2006  received signal strength of the acknowledgement data frame received in block  2004 , and WTP  1902  determines that the second beacons should be customized to have a transmit power that is a function of the received signal strength, but not equal to the received signal strength. For example, in certain embodiments, WTP  1902  determines that the second beacons should be customized to have a transmit power that is inversely proportional to received signal strength of the acknowledgement data frame received in block  2004 . As another example, in particular embodiments, WTP  1902  determines that the second beacons should be customized to have a repetition rate and/or guard interval that is a function of an identity of the receiving UE station, such as by consulting a database that associates UE station identity with minimum required repetition rate and/or guard interval. 
     Referring again to  FIG. 20 , in a block  2010  of method  2000 , WTP  1902  transmits the one or more second Unicast beacons to the UE station. In one example of block  2020 , WTP  1902  transmits one or more instances of custom Unicast beacons  1916  to UE station  1904 , and in another example of block  2010 , WTP  1902  transmits one or more instances of custom Unicast beacons  1918  to UE station  1906 . In some embodiments, custom Unicast beacons  1916  and  1918  are Wi-Fi-based beacons. 
     In some embodiments, WTP  1902  in configured to indefinitely transmit the same customized Unicast beacons to a given UE station. In some other embodiments, WTP  1902  is configured to update customization of Unicast beacons, such as on a periodic basis, in response to a change in operating conditions of a receiving UE station, and/or in response to failure to receive an acknowledgement data frame from the UE station. For example,  FIG. 21  is a dataflow diagram illustrating one example of WTP  1902  transmitting beacons to UE station  1904 . At time t o  in  FIG. 21 , WTP  1902  transmits default Unicast beacon  1908  to UE station  1904 , and UE station responds by transmitting acknowledgement data frame  1912  to WTP  1902  at time t 1 . WTP  1902  transmits successive custom Unicast beacons  1916  to UE station  1904  at times t 2 , t 4 , t 6 , and t 8 , and UE station  1904  responds by transmitting acknowledgement data frames  2102 ,  2104 ,  2106 , and  2108  at times t 3 , t 5 , t 7 , and t 9 , respectively. Thus, WTP  1902  transmits four instances of custom Unicast beacon  1916  to UE station  1904 , beginning at time t 2 . At times t 10  and t 12 , however, WTP  1902  transmits a custom Unicast beacon  2110 , instead of custom Unicast beacon  1916 , to UE station  1904 , and UE station  1904  responds by transmitting acknowledgement data frames  2112  and  2114  at times t 11  and t 13 , respectively. WTP  1902  changes beacon customization at time t 10 , for example, in response to a change in operating conditions of UE station  1904 , such as determined from acknowledgement data frame  2108  received at time t 9 . 
     In some embodiments, WTP  1902  is configured to interleave transmission of custom Unicast beacons with transmission of default Unicast beacons, such as in cases where a UE station requires a periodic default Unicast beacon to maintain a connection with WTP  1902 . For example,  FIG. 22  is a dataflow diagram illustrating another example of WTP  1902  transmitting beacons to UE station  1904 . At time t o  in  FIG. 22 , WTP  1902  transmits default Unicast beacon  1908  to UE station  1904 , and UE station  1904  responds by transmitting acknowledgement data frame  1912  to WTP  1902  at time t 1 . WTP  1902  transmits two instances of custom Unicast beacon  1916  to UE station  1904  at times t 2 , and t 4 , and UE station  1904  responds by transmitting acknowledgement data frames  2202  and  2404  at times t 3  and t 5 , respectively. WTP  1902  then transmits one instance of default Unicast beacon  1908  to UE station  1904  at time t 6 , and UE station  1904  responds by transmitting an acknowledgement data frame  2206  at time t 7 . WTP  1902  next transmits two instances of custom Unicast beacon  1916  to UE station  1904  at times t 8  and t 10 , and UE station  1904  responds by transmitting acknowledgement data frames  2208  and  2210  at times t 9  and t 11 , respectively. WTP  1902  then transmits another instance of default Unicast beacon  1908  to UE station  1904  at time t 12 , and UE station  1904  responds by transmitting an acknowledgement data frame  2212  at time t 13 . Accordingly, in this embodiment, WTP  1902  is configured to transmit Unicast beacons having the following pattern: two custom Unicast beacons  1916 , one default Unicast beacon  1908 , two custom Unicast beacons  1916 , one default Unicast beacon  1908 , two custom Unicast beacons  1916 , and so on. 
       FIG. 23  is a dataflow diagram illustrating yet another example of WTP  1902  transmitting beacons to UE station  1904 . In this example, WTP  1902  is configured to transmit Unicast beacons having the following pattern, after receiving acknowledgement data frame  1912 : two custom Unicast beacons  1916 , one custom Unicast beacon  2306 , two custom Unicast beacons  1916 , one custom Unicast beacon  2306 , two custom Unicast beacons  1906 , and so on. In one embodiment, custom Unicast beacons  2306  have a larger payload than custom Unicast beacons  1916 , such as in embodiments where UE station  1904  requires that beacons periodically include certain information to maintain a connection with WTP  1902 . UE  1904  responds to receipt of custom Unicast beacons by transmitting acknowledgement data frames  2302 ,  2304 ,  2308 ,  2310 ,  2312 ,  2314  to UE station  1904  at times t 3 , t 5 , t 7 , t 9 , t 11 , and t 13 , respectively. 
       FIG. 24  is a dataflow diagram illustrating another example of WTP  1902  transmitting beacons to UE station  1904 . At time t o  in  FIG. 24 , WTP  1902  transmits default Unicast beacon  1908  to UE station  1904 , and UE station  1904  responds by transmitting acknowledgement data frame  1912  to WTP  1902  at time t 1 . WTP  1902  transmits custom Unicast beacon  1916  to UE station  1904  at times t 2 . WTP  1902  expects to receive an acknowledgement data frame from UE station  1904  at time t 3 , but no acknowledgement data frame arrives, due to unsuccessful receipt of custom Unicast beacon  1916  by UE station  1904 . In response, WTP  1902  transmits custom Unicast beacon  2402  to UE station  1904  at time t 4 , and UE station  1904  responds by transmitting acknowledgement data frame  2404  to WTP  1902  at time t 5 . WTP  1902  customizes custom Unicast beacon  2402  such that custom Unicast beacon  2402  is more-likely to be successfully received by UE station  1904  than custom Unicast beacon  1916 , at the cost of custom Unicast beacon  2402  requiring more airtime and/or transmission power than custom Unicast beacon  1916 . For example, custom Unicast beacon  2402  may have a lower modulation mode, a higher transmission power, a lower data rate, a larger payload, and/or a smaller guard interval, than custom Unicast beacon  1916 . WTP  1902  transmits additional instances of custom Unicast beacon  2402  to UE station  1904  at times t 6 , t 8 , t 10 , and t 12 , and UE station  1904  responds by transmitting acknowledgement data frames  2406 ,  2408 ,  2410 , and  2412  to WTP  1902  at times t 7 , t 9 , t ii , and t 13 , respectively. 
     In some embodiments, WTP  1902  is further configured transmit default and/or custom Unicast beacons concurrently with other data frames, to help minimize airtime dedicated to transmission of Unicast beacons. For example, in some embodiments, WTP  1902  is configured to (a) transmit Unicast beacons to one UE station in parallel with packets to one or more other UE stations using multi-user MIMO techniques, (b) aggregate one or more Unicast beacons with one or more additional data frames, and/or (c) transmit one or more Unicast beacons via one or more subcarriers of a wireless communication signal, where other subcarriers of the wireless communication signal transmit one or more additional data frames. These three techniques for transmitting Unicast beacons concurrently with other data frames can also be used in wireless communication systems which do not support customizing Unicast beacons. 
       FIG. 25  is a block diagram illustrating a wireless communication system  2500  configured to aggregate a Unicast beacon with one or more additional data frames into an aggregated data unit. System  2500  includes a WTP  2502 , an instance of UE station  1904 , and an instance of UE station  1906 . System  2500  could be modified to include a different number of WTPs and/or a different number of UE stations without departing from the scope hereof. 
     WTP  2502  is configured to convert electrical or optical signals to wireless signals, and vice versa, to enable one or more UE stations, such as UE stations  1904  and  1906 , to wirelessly communicate with a core network (not shown) communicatively coupled to WTP  2502 . In some embodiments, WTP  2502  operates according to a Wi-Fi-based standard or other IEEE 802.11-based standard. UE stations  1904  and  1906  communicate with WTP  2502  using RF signals, and UE stations  1904  and  1906  are not necessarily part of wireless communication system  2500 . In some embodiments, WTP  2502  is configured to customize Unicast beacons for recipient UE stations, such as discussed above with respect to  FIGS. 19-24 . In some other embodiments, WTP  2502  is not configured to customize Unicast beacons. 
     WTP  2502  is configured to aggregate a Unicast beacon with one or more additional data frames into an aggregated data unit, and WTP  2502  is configured to transmit the aggregated data unit to a UE station. For example, WTP  2502  is configured to aggregate a custom Unicast beacon  2516  with one or more additional data frames  2506  into an aggregated data unit  2502 , and WTP  2502  is configured to transmit aggregated data unit  2502  to UE station  1904 . As another example, WTP  2502  is configured to aggregate a custom Unicast beacon  2518  with one or more additional data frames  2508  into an aggregated data unit  2504 , and WTP  2502  is configured to transmit aggregated data unit  2504  to UE station  1904 . Unicast beacons  2516  and  2518  are, for example, default Unicast beacons or custom Unicast beacons, and in some embodiments, Unicast beacons  2516  and  2518  are Wi-Fi-based beacons. In some embodiments, each of aggregated data unit  2502  and aggregated data unit  2504  is an aggregated media access control protocol data unit (A-MPDU). Transmitting Unicast beacons  2516  and  2518  via respective aggregated data units  2502  and  2504  helps minimize airtime associated with beacon transmission by sharing data transmission overhead with additional data frames  2506  and  2508 , respectively. 
     In some embodiments, WTP  2502  is configured to aggregate a Unicast beacon with one or more additional frames in response to the additional data frames being scheduled for transmission or being due for transmission. For example, in certain embodiments, WTP  2502  is configured to aggregate Unicast beacon  2516  with one or more additional frames  2506  in response to additional data frames  2506  being scheduled for transmission or being due for transmission. Additionally, in particular embodiments, WTP  2502  is configured to aggregate a Unicast beacon with one or more additional frames in response to the additional data frames being scheduled for transmission or being due for transmission, even if the Unicast beacon is not scheduled for transmission or due for transmission. Furthermore, in some embodiments, WTP  2502  is configured to aggregate a Unicast beacon with one or more additional frames in response to the Unicast beacon being scheduled for transmission or being due for transmission. For example, in certain embodiments, WTP  2502  is configured to aggregate Unicast beacon with one or more additional data frames  2508  in response to Unicast beacon  2518  being schedule for transmission or being due for transmission. 
       FIG. 26  is a block diagram illustrating a wireless communication system  2600  configured to transmit one or more Unicast beacons via one or more subcarriers of a wireless communication signal. System  2600  includes a WTP  2602  and an instance of UE station  1904 . System  2600  could be modified to include a different number of WTPs and/or a different number of UE stations without departing from the scope hereof. 
     WTP  2602  is configured to convert electrical or optical signals to wireless signals, and vice versa, to enable one or more UE stations, such as UE station  1904 , to wirelessly communicate with a core network (not shown) communicatively coupled to WTP  2602 . In some embodiments, WTP  2602  operates according to a Wi-Fi-based standard or other IEEE 802.11-based standard. UE station  1904  communicates with WTP  2602  using RF signals, and UE station  1904  and is not necessarily part of wireless communication system  2600 . In some embodiments, WTP  2602  is configured to customize Unicast beacons for recipient UE stations, such as discussed above with respect to  FIGS. 19-24 . In some other embodiments, WTP  2602  is not configured to customize Unicast beacons. 
     WTP  2602  is configured to transmit a Unicast beacon  2616  to UE station  1904  via one or more first sub-carriers  2604  of a wireless communication signal  2606 , and WTP  2602  is further configured to transmit one or more additional data frames  2610  to UE station  1904  via one or more second sub-carriers  2608  of wireless communication signal  2606 . In some embodiments, wireless communication signal  2606  is an orthogonal frequency-division multiple access (OFDMA) wireless communication signal. Transmitting Unicast beacon  2616  and additional data frames  2610  via respective subcarriers  2604  and  2608  of a wireless communication signal  2606  helps minimize airtime associated with beacon transmission by sharing data transmission overhead with additional data frames  2610 . 
       FIG. 27  is a block diagram of a WTP  2700 , which is one possible embodiment of WTP  1902  of  FIG. 19 . However, it should be understood that WTP  1902  can be embodied in other manners. 
     WTP  2700  includes a processing subsystem  2702 , a memory subsystem  2704 , and a radio subsystem  2706 . Processing subsystem  2702  is communicatively coupled to each of memory subsystem  2704  and radio subsystem  2706 , and processing subsystem  2702  includes, for example, one or more processing devices (not shown) located at a single location or distributed among multiple locations, such as in multiple data centers. The one or more processing devices of processing subsystem  2702  need not all have the same configuration. For example, processing subsystem  2702  could include both microprocessors in a local server and processing resources in a cloud computing service. 
     Memory subsystem  2704  includes, for example, one or more memory devices (not shown) located at a single location or distributed among multiple locations. The one or more memory devices of memory subsystem  2704  need not all have the same configuration. For example, memory subsystem  2704  could include one or more solid-state memory modules and one or more magnetic data storage devices. Radio subsystem  2706  is configured to convert electrical or optical signals to wireless signals, and vice versa, to enable one or more UE stations to wirelessly communicate with a core network (not shown) communicatively coupled to WTP  2700 . In some embodiments, WTP  2700  operates according to a Wi-Fi-based standard or other IEEE 802.11-based standard 
     Processing subsystem  2702  is configured to execute characteristic determination instructions  2708  stored in memory subsystem  2704  to determine characteristics of one or more UE stations. For example, in some embodiments, processing subsystem  2702  is configured to execute characteristic determination instructions  2708  to perform block  2006  of  FIG. 20 . Processing subsystem  2702  is additionally configured to execute beacon customizing instructions  2710  to customize one or more Unicast beacons for transmission to respective UE stations. For example, in some embodiments, processing subsystem  2702  is configured to execute beacon customizing instructions  2710  to perform block  2008  of  FIG. 20 . 
     One or more of aggregation instructions  2712  and subcarrier allocation instructions  2714  are optionally further stored in memory subsystem  2704 . In embodiments where memory subsystem  2704  stores aggregation instructions  2712 , processing subsystem  2702  is configured to execute instructions  2712  to aggregate one or more Unicast beacons with one or more additional data frames, such as in a manner like that discussed above with respect to  FIG. 25 . In embodiments where memory subsystem  2704  stores subcarrier allocation instructions  2714 , processing subsystem  2702  is configured to execute instructions  2714  to transmit one or more Unicast beacons via one or more subcarriers of a wireless communication signal, such as in a manner like that discussed above with respect to  FIG. 26 . In some embodiments, memory subsystem  2704  further stores instructions (not shown) to perform functions of WTP  102  discussed above. Processing subsystem  2702  could be configured to execute additional instructions (not shown) to perform one or more additional functions and/or one or more alternative functions without departing from the scope hereof. 
     Combinations of Features 
     Features described above may be combined in various ways without departing from the scope hereof. The following examples illustrate some possible combinations: 
     (A1) A method for providing continuous wireless communication service may include (1) transmitting a first Unicast beacon from a first wireless termination point (WTP) to a first user equipment (UE) station, (2) after transmitting the first Unicast beacon to the first UE station, handing off the first UE station from the first WTP to a second WTP, and (3) transmitting a second Unicast beacon from the second WTP to the first UE station, each of the first and second Unicast beacons including a common first basic service set identifier (BSSID). 
     (A2) The method denoted as (A1) may further include transmitting a third Unicast beacon from the first WTP to a second UE station, the third Unicast beacon including a second BSSID that is different from the first BSSID. 
     (A3) In any one of the methods denoted as (A1) and (A2), each of the first Unicast beacon and the second Unicast beacon may be a Wi-Fi-based beacon. 
     (A4) Any one of the methods denoted as (A1) through (A3) may further include handing off the first UE station from the first WTP to the second WTP at least partially in response to a signal strength of the second WTP at the first UE station. 
     (A5) Any one of the methods denoted as (A1) through (A4) may further include reducing a transmit power of the first WTP for data frames addressed to the first UE station, while handing off the first UE station from the first WTP to the second WTP. 
     (A6) Any one of the methods denoted as (A1) through (A5) may further include (1) transmitting a first signal strength table from the first WTP to a first access controller, the first signal strength table including signal strength of the one or more UE stations at the first WTP, and (2) transmitting a second signal strength table from the second WTP to the first access controller, the second signal strength table including signal strength of the one or more UE stations at the second WTP. 
     (A7) The method denoted as (A6) may further include handing off the first UE station from the first WTP to the second WTP at least partially in response to data contained in the first and second signal strength tables. 
     (A8) Any one of the methods denoted as (A6) and (A7) may further include using the first access controller to manage the first UE station. 
     (A9) Any one of the methods denoted as (A6) through (A8) may further include (1) transmitting the first signal strength table from the first WTP to a second access controller different from the first access controller, (2) transmitting the second signal strength table from the second WTP to the second access controller, and (3) at the second access controller, initiating serving of the first UE station by the second WTP at least partially in response to data contained in the first and second signal strength tables. 
     (A10) The method denoted as (A9) may further include changing a managing access controller of the first UE station from the first access controller to the second access controller, before handing off the first UE station from the first WTP to the second WTP. 
     (A11) Any one of the methods denoted as (A1) through (A10) may further include (1) operating the first WTP on a first wireless channel, (2) operating the second WTP on a second wireless channel different from the first wireless channel, and (3) including a channel switch announcement in the second Unicast beacon, the channel switch announcement announcing a change from the first wireless channel to the second wireless channel. 
     (B1) A method for providing individualized wireless communication service may include (1) transmitting a first Unicast beacon from a first wireless termination point (WTP) to a first user equipment (UE) station, and (2) transmitting a second Unicast beacon from the first WTP to a second UE station. 
     (B2) In the method denoted as (A1), the first Unicast beacon may include a first basic service set identifier (BSSID) associated with the first UE station, and the second Unicast beacon may include a second BSSID. 
     (B3) In the method denoted as (B2), the second BSSID may be different from the first BSSID. 
     (B4) In the method denoted as (B2), the second BSSID and the first BSSID may have a common value. 
     (B5) Any one of the methods denoted as (B2) through (B4) may further include associating each of the first and second BSSIDs with a common service set identifier (SSID). 
     (B6) Any one of the methods denoted as (B2) through (B5) may further include associating first and second types of wireless communication service with the first and second BSSIDs, respectively, the first and second types of wireless communication service having at least one differing wireless service characteristic. 
     (B7) In the method denoted as (B6), the at least one differing wireless service characteristic may include a differing quality of service (QoS) characteristic. 
     (B8) In any one of the methods denoted as (B1) through (B7), each of the first Unicast beacon and the second Unicast beacon may be a Wi-Fi-based beacon. 
     (C1) A method for customizing wireless communication beacons may include (1) customizing, at a first wireless termination point (WTP), one or more Unicast beacons for a first user equipment (UE) station, based at least in part on one or more characteristics of the first UE station, and (2) transmitting the one or more Unicast beacons from the first WTP to the first UE station. 
     (C2) The method denoted as (C1) may further include (1) transmitting a first Unicast beacon from the first WTP to the first user equipment (UE) station, (2) receiving, at the first WTP, an acknowledgement data frame from the first UE station, and (3) determining the one or more characteristics of the first UE station from the acknowledgement data frame. 
     (C3) In any one of the methods denoted as (C1) and (C2), customizing the one or more Unicast beacons for the first UE station may include selecting a modulation mode of the one or more Unicast beacons, based at least in part on the one or more characteristics of the first UE station. 
     (C4) In any one of the methods denoted as (C1) through (C3), customizing the one or more Unicast beacons for the first UE station may include selecting a transmission power of the one or more Unicast beacons, based at least in part on the one or more characteristics of the first UE station. 
     (C5) In any one of the methods denoted as (C1) through (C4), the one or more Unicast beacons for the first UE station may include selecting a data rate of the one or more Unicast beacons, based at least in part on the one or more characteristics of the first UE station. 
     (C6) In any one of the methods denoted as (C1) through (C5), customizing the one or more Unicast beacons for the first UE station may include selecting a repetition rate of the one or more Unicast beacons, based at least in part on the one or more characteristics of the first UE station. 
     (C7) In any one of the methods denoted as (C1) through (C6), customizing the one or more Unicast beacons for the first UE station may include selecting a transmission direction of the one or more Unicast beacons, based at least in part on the one or more characteristics of the first UE station. 
     (C8) In any one of the methods denoted as (C1) through (C7), customizing the one or more Unicast beacons for the first UE station may include selecting a payload of the one or more Unicast beacons, based at least in part on the one or more characteristics of the first UE station. 
     (C9) In any one of the methods denoted as (C1) through (C8), customizing the one or more Unicast beacons for the first UE station may include selecting a multiple-input and multiple-output (MIMO) transmission order of the one or more Unicast beacons, based at least in part on the one or more characteristics of the first UE station. 
     (C10) In any one of the methods denoted as (C1) through (C9), customizing the one or more Unicast beacons for the first UE station may include selecting a channel width of the one or more Unicast beacons, based at least in part on the one or more characteristics of the first UE station. 
     (C11) In any one of the methods denoted as (C1) through (C10), customizing the one or more Unicast beacons for the first UE station may include selecting a guard interval of the one or more Unicast beacons, based at least in part on the one or more characteristics of the first UE station. 
     (C12) In any one of the methods denoted as (C1) through (C11), transmitting the one or more Unicast beacons from the first WTP to the first UE station may include aggregating the one or more Unicast beacons with one or more additional data frames. 
     (C13) In any one of the methods denoted as (C1) through (C12), transmitting the one or more Unicast beacons from the first WTP to the first UE station may include (1) transmitting the one or more Unicast beacons via one or more first sub-carriers of a wireless communication signal and (2) transmitting one or more additional data frames via one or more second sub-carriers of the wireless communication signal. 
     (C14) In any one of the methods denoted as (C1) through (C13), each of the one or more Unicast beacons may be a Wi-Fi-based beacon. 
     (C15) In any one of the methods denoted as (C1) through (C14), each of the one or more characteristics of the first UE station may be either a static characteristic of the first UE station or a dynamic characteristic of the first UE station. 
     (D1) A method for transmitting wireless communication beacons may include (1) aggregating a Unicast beacon with one or more additional data frames into an aggregated data unit and (2) transmitting the aggregated data unit from a first wireless termination point (WTP) to a first user equipment (UE) station. 
     (D2) In the method denoted as (D1), the aggregated data unit may include an aggregated media access control protocol data unit (A-MPDU). 
     (D3) Any one of the methods denoted as (D1) and (D2) may further include aggregating the Unicast beacon with the one or more additional data frames into the aggregated data unit in response to the one or more additional data frames being scheduled for transmission or being due for transmission. 
     (D4) Any one of the methods denoted as (D1) and (D2) may further include aggregating the Unicast beacon with the one or more additional data frames into the aggregated data unit in response to the Unicast beacon being scheduled for transmission or being due for transmission. 
     (D5) In any one of the methods denoted as (D1) and (D2), the Unicast beacon is optionally not scheduled for transmission and is not due for transmission, when aggregating the Unicast beacon with the one or more additional data frames into the aggregated data unit. 
     (E1) A method for transmitting wireless communication beacons may include (1) transmitting a Unicast beacon from a first wireless termination point (WTP) to a first user equipment (UE) station via one or more first sub-carriers of a wireless communication signal and (2) transmitting one or more additional data frames from the first WTP to one or more UE stations via one or more second sub-carriers of the wireless communication signal. 
     Changes may be made in the above methods, devices, and systems without departing from the scope hereof. It should thus be noted that the matter contained in the above description and shown in the accompanying drawings should be interpreted as illustrative and not in a limiting sense. The following claims are intended to cover generic and specific features described herein, as well as all statements of the scope of the present method and system, which, as a matter of language, might be said to fall therebetween.