PATENT DOCUMENT

Publication Number: US-11032763-B2
Application Number: US-201916286156-A
Country: US
Kind Code: B2

Title: Apparatus, method, and medium for implementing a target wake time

Abstract:
Some embodiments include an apparatus and method for a mobile access point (AP) station that operates in an always-on soft AP mode where a station is associated with the mobile AP station, and switch back to operate as a station in an infrastructure mode with an AP. For example, in an always-on soft AP mode, the mobile AP station may implement a target wake time (TWT) responder power save mode feature. The mobile AP station may maintain a wake window after a beacon to enable unassociated devices to associate; establish a broadcast TWT schedule for unassociated TWT-capable devices to associate; schedule TWT for associated devices; go to sleep outside of the scheduled TWT of the associated devices; and switch back to infrastructure mode to perform as a station and maintain a connection with an AP.

Claims:
What is claimed is: 
     
       1. A mobile access point (AP) station, comprising:
 a transceiver configured to transmit and receive wireless communications; and 
 one or more processors communicatively coupled to the transceiver and configured to:
 operate in an always-on soft AP mode comprising implementing a target wake time (TWT) responder power save mode; 
 while operating in the always-on soft AP mode, enable a first station to associate with the mobile AP station; 
 while the first station is associated with the mobile AP station in the always-on soft AP mode, concurrently operate the mobile AP station as a second station in an infrastructure mode associated with an AP; 
 transmit, via the transceiver, infrastructure traffic to an AP; and 
 dynamically adjust a TWT for the first station based at least in part on the infrastructure traffic between the mobile AP station and the AP. 
 
 
     
     
       2. The mobile AP station of  claim 1 , wherein the one or more processors are further configured to:
 determine a broadcast TWT schedule; and 
 advertise the broadcast TWT schedule in a beacon, wherein the broadcast TWT schedule indicates a TWT for an unassociated TWT-capable station service period during which an unassociated TWT-capable station may wake to associate with the mobile AP station. 
 
     
     
       3. The mobile AP station of  claim 2 , wherein the one or more processors are further configured to enable the first station to request setting up the TWT for the first station. 
     
     
       4. The mobile AP station of  claim 3 , wherein to enable the first station to request setting up the TWT, the one or more processors are further configured to:
 set a TWT Required field to a predetermined value in a high efficiency operation element in a beacon; 
 in response to the TWT Required field being set to the predetermined value, receive a TWT setup request from the first station; and 
 in response to the TWT setup request received, transmit a TWT schedule to the first station. 
 
     
     
       5. The mobile AP station of  claim 4 , wherein, the one or more processors are further configured to inform the first station that the mobile AP station is not available outside of the TWT schedule, wherein the one or more processors are configured to:
 set a TWT Responder Power Save field in a TWT Element; and 
 transmit the TWT element to the first station. 
 
     
     
       6. The mobile AP station of  claim 3 , wherein the one or more processors are further configured to enter a sleep mode outside of the TWT for the first station. 
     
     
       7. The mobile AP station of  claim 3 , wherein the one or more processors are further configured to remain active outside of the TWT for the first station. 
     
     
       8. The mobile AP station of  claim 2 , wherein the one or more processors are configured to: based on activity in the TWT for an unassociated TWT-capable station service period, adjust a duration of a next TWT for an unassociated TWT-capable station service period. 
     
     
       9. The mobile AP station of  claim 1 , wherein the dynamically adjusting the TWT for the first station is based at least in part on a number of stations associated with the mobile AP station. 
     
     
       10. The mobile AP station of  claim 1 , wherein the dynamically adjusting the TWT for the first station is based at least in part on a traffic load between the mobile AP station and one or more stations associated with the mobile AP station. 
     
     
       11. The mobile AP station of  claim 1 , wherein the one or more processors are further configured to set up a wake window during which a new unassociated station may join a network of the mobile AP station that includes the first station, and wherein the wake window is temporally adjacent to a beacon. 
     
     
       12. The mobile AP station of  claim 11 , wherein the one or more processors are further configured to dynamically adjust the wake window based at least in part on a number of stations associated with the mobile AP station. 
     
     
       13. The mobile AP station of  claim 1 , wherein the one or more processors are configured to: transmit an indication to the AP that the mobile AP station is entering a sleep mode before communicating with the first station. 
     
     
       14. A method for a mobile access point (AP) station, comprising:
 operating in an always-on soft AP mode, wherein the operating comprises implementing a target wake time (TWT) responder power save mode; 
 while operating in the always-on soft AP mode, concurrently operating the mobile AP station as a station in an infrastructure mode associated with an AP; 
 transmitting infrastructure traffic to an AP; and 
 dynamically adjusting a TWT for a first station based at least in part on the infrastructure traffic between the mobile AP station and the AP. 
 
     
     
       15. The method of  claim 14 , further comprising:
 determining a broadcast TWT schedule; and 
 advertising the broadcast TWT schedule in a beacon, wherein the broadcast TWT schedule indicates a TWT for an unassociated TWT-capable station service period during which an unassociated TWT-capable station may wake to associate with the mobile AP station. 
 
     
     
       16. The method of  claim 15 , further comprising: based on activity in the TWT for an unassociated TWT-capable station service period, adjusting a duration of a next TWT for an unassociated TWT-capable station service period. 
     
     
       17. The method of  claim 14 , further comprising:
 while operating in the always-on soft AP mode, enabling the first station to associate with the mobile AP station; and 
 enabling the first station to request setting up the TWT for the first station. 
 
     
     
       18. The method of  claim 17 , further comprising dynamically adjusting the TWT for the first station based at least in part on: a number of stations associated with the mobile AP station; or a traffic load between the mobile AP station and one or more stations associated with the mobile AP station. 
     
     
       19. A non-transitory computer-readable medium storing instructions that, when executed by a processor of a mobile access point (AP) station, cause the processor to perform operations, the operations comprising:
 operating in an always-on soft AP mode comprising implementing a target wake time (TWT) responder power save mode; 
 determining a service period during which an unassociated TWT-capable station may wake to associate with the mobile AP station; 
 enabling a first station that is a TWT-capable station to associate with the mobile AP station; 
 enabling the first station to request setting up a TWT; 
 receiving a TWT setup request from the first station; 
 determining an infrastructure mode period, wherein the mobile AP station operates as a second station to transmit infrastructure traffic to an AP; 
 while operating in the always-on soft AP mode, concurrently operating the mobile AP station as the second station in an infrastructure mode associated with the AP; 
 transmitting infrastructure traffic to the AP during the infrastructure mode period; and 
 dynamically adjusting the TWT for the first station based at least in part on the infrastructure traffic between the mobile AP station and the AP. 
 
     
     
       20. The non-transitory computer-readable medium of  claim 19 , wherein the operations further comprise dynamically adjusting the TWT for the first station based at least in part on: a number of stations associated with the mobile AP station; or a traffic load between the mobile AP station and one or more stations associated with the mobile AP station.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims benefit of U.S. Provisional Application No. 62/692,562, filed on Jun. 29, 2018, entitled, Apparatus and Method for a Mobile Access Point Station, which is incorporated herein by reference in its entirety. 
    
    
     BACKGROUND 
     Field 
     The described embodiments generally relate to channel access in wireless communications. 
     Related Art 
     A wireless local area Network (WLAN) access point (AP) transmits infrastructure traffic, is always active, and can be reached whenever associated or unassociated stations choose to communicate with the AP. Being always active, the AP operates in an always-on mode and cannot go into a power-save mode. A mobile device may perform soft AP functions that enable other devices to access a network. Like an AP, a soft AP should be always-on so that associated or unassociated stations can communicate with the soft AP. Thus, a soft AP cannot enter a power save mode. But the mobile device performing soft AP functions is battery-operated, and being always-on causes excessive power consumption on the battery. Consequently, a soft AP function on a mobile device is turned on by a user for a given period and then turned off. Further, a mobile device can operate as a station in infrastructure mode to transmit infrastructure traffic with an AP. But, once soft AP functions on a mobile device are turned on, the mobile device cannot switch back to infrastructure mode as a station to communicate with the AP; this is because a soft AP is required to be always available to associated stations. 
     SUMMARY 
     Some embodiments include an apparatus and method for a mobile access point (AP) station. A mobile AP station is a mobile device that operates in an always-on soft AP mode that provides soft AP mode functions, and is capable of switching back to infrastructure mode to operate as an associated station in an infrastructure mode with an AP. For example, the mobile AP station may implement a target wake time (TWT) responder power save mode feature with stations associated with the mobile AP station. The mobile AP station may: maintain a wake window after each beacon or one or more selected beacons to allow unassociated devices to communicate with the mobile AP station; establish a broadcast TWT schedule for unassociated TWT-capable devices to communicate with the mobile AP station; schedule TWT for associated devices; go to sleep outside of the scheduled TWT of the associated devices; and concurrently perform as a station and maintain a connection (e.g., wireless local area network (WLAN) access) with an AP. Thus, a mobile AP station in an always-on soft AP mode may: go to sleep, switch back to infrastructure mode and communicate infrastructure traffic to the AP, switch back to operate in a soft AP mode and communicate with of one of the associated devices of the mobile AP station at a scheduled TWT, or remain active. 
     Some embodiments include a mobile AP station that may operate in an always-on soft AP mode that includes implementing a TWT responder power save mode. While operating in the always-on soft AP mode, the mobile AP station may enable a first station to associate with the mobile AP station, and while the first station is associated with the mobile AP station, switch back to infrastructure mode to transmit infrastructure traffic to an AP. In addition, the mobile AP station may implement a broadcast TWT schedule, and advertise the broadcast TWT schedule in a beacon. The broadcast TWT schedule indicates a service period during which an unassociated TWT-capable station (e.g., an IEEE 802.11ax device) may wake at a known time window (e.g., when the mobile AP station is available) to associate with the mobile AP station. The mobile AP station may also enable the first station to request setting up a TWT for the first station by setting a TWT Required field to a predetermined value (e.g., “1”) in a high efficiency operation element in a beacon. In response to the TWT Required field being set to the predetermined value (e.g., “1”), the mobile AP station receives a TWT setup request from the first station, and in response to the TWT setup request received, transmits a TWT schedule to the first station. The mobile AP station may inform the first station that the mobile AP station is not available outside of the TWT schedule by setting a TWT Responder Power Save field in a TWT Element, and transmitting the TWT element to the first station. The mobile AP station may enter a sleep mode outside of the TWT for the first station, remain active outside of the TWT for the first station, or dynamically adjust the TWT for the first station. Dynamically adjusting the TWT for the first station may be based in part on a number of stations associated with the mobile AP station, a traffic load between the mobile AP station and one or more stations associated with the mobile AP station, and/or the infrastructure traffic between the mobile AP station and the AP. The mobile AP station may set up a wake window during which new unassociated stations may join a network of the mobile AP station that includes the first station, and where the wake window is temporally adjacent to a beacon. The mobile AP station may dynamically adjust the wake window based at least in part on a number of stations associated with the mobile AP station. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
       The accompanying drawings, which are incorporated herein and form part of the specification, illustrate the presented disclosure and, together with the description, further serve to explain the principles of the disclosure and enable a person of skill in the relevant art(s) to make and use the disclosure. 
         FIG. 1  illustrates an example system implementing a mobile access point (AP) station, according to some embodiments of the disclosure. 
         FIG. 2  illustrates a block diagram of an example wireless system for a mobile AP station, according to some embodiments of the disclosure. 
         FIG. 3  illustrates an example operation of a mobile AP station with no associated devices, according to some embodiments of the disclosure. 
         FIG. 4  illustrates an example operation of a mobile AP station with associated devices, according to some embodiments of the disclosure. 
         FIG. 5  illustrates an example operation of a mobile AP station with unassociated target wake time (TWT)-capable devices, according to some embodiments of the disclosure. 
         FIG. 6  illustrates an example method for a wireless system supporting a mobile AP station, according to some embodiments of the disclosure. 
         FIG. 7  is an example computer system for implementing some embodiments or portion(s) thereof. 
     
    
    
     The presented disclosure is described with reference to the accompanying drawings. In the drawings, generally, like reference numbers indicate identical or functionally similar elements. Additionally, generally, the left-most digit(s) of a reference number identifies the drawing in which the reference number first appears. 
     DETAILED DESCRIPTION 
     Some embodiments include an apparatus, method, and computer program product for a mobile access point (AP) station that operates in an always-on soft AP mode where a station is associated with the mobile AP station, and operate as a station in an infrastructure mode with an AP. For example, in an always-on soft AP mode, the mobile AP station may implement a target wake time (TWT) responder power save mode feature. The mobile AP station may maintain a wake window after a beacon to enable unassociated devices to associate; establish a broadcast TWT schedule for unassociated TWT-capable devices to associate; schedule TWT for associated devices; go to sleep outside of the scheduled TWT of the associated devices; and perform as a station and maintain a connection with an AP (e.g., to transmit infrastructure traffic to the AP.) 
       FIG. 1  illustrates an example system  100  implementing a mobile access point (AP) station  150 , according to some embodiments of the disclosure. A mobile AP station  150  is different than a conventional mobile device that performs soft AP functions. Example system  100  is provided for the purpose of illustration only and is not limiting of the disclosed embodiments. System  100  may include but is not limited to stations  120 , access point (AP)  110 , network  130 , and mobile AP station  150 . Stations  120   a - 120   e  may include but are not limited to WLAN stations such as wireless communication devices, smart phones, laptops, desktops, tablets, personal assistants, monitors, and televisions. Stations  120  may support latency sensitive applications (e.g., video and/or audio streaming). AP  110  may include but are not limited to WLAN electronic devices such as a wireless router, a wearable device (e.g., a smart watch), a wireless communication device (e.g., a smart phone), or a combination thereof. Network  130  may be the Internet and/or a WLAN. Infrastructure mode communications are shown as wireless communications  140 . Soft AP mode communications are shown as wireless communications  155 . Mobile AP station  150  may include but is not limited to WLAN stations such as wireless communication devices, smart phones, laptops, tablets, personal assistants, monitors, and televisions. 
     Mobile AP station  150  operates in an always-on soft AP mode, and is capable of switching back to infrastructure mode to operate as a station in an infrastructure mode with AP  110 . Since mobile AP station  150  operates in an always-on soft AP mode, stations  120   b - 120   e  may always discover mobile AP station  150 . Stations  120   b - 120   e  may associate with mobile AP station  150  and join a network of mobile AP station  150 . Concurrent to being in the always-on soft AP mode where a station (e.g.,  120   b ) is associated with mobile AP station  150 , mobile AP station  150  can switch back to infrastructure mode to operate as a station in an infrastructure mode, and may transmit and/or receive infrastructure traffic shown as  140   b  to AP  110 . Mobile AP station  150  may use any mechanism such as a Power Management bit in a MAC packet header to inform AP  110  that mobile AP station  150  is going to sleep before switching back to perform soft AP functionality with other devices such as stations  120   a - 120   c . A mobile AP station by default may be in always-on soft AP mode. A user may change a setting, such as manually turning off the always-on soft AP mode. 
     In some embodiments, when mobile AP station  150  operates in infrastructure mode as a station with AP  110 , mobile AP station  150  may arrange a target wake time (TWT) for infrastructure mode with AP  110 , or AP  110  may arrange a TWT with mobile AP station  150 . Outside of these arranged TWTs with AP  110 , mobile AP station  150  may switch back to perform soft AP functionalities with stations  120   a - 120   c  that are associated with mobile AP station  150 . 
       FIG. 2  illustrates a block diagram of an example wireless system  200  of a system  100  implementing a mobile AP station, according to some embodiments of the disclosure. System  200  may be any of the electronic devices (e.g., AP  110 , station  120 , mobile AP station  150 ) of system  100 . System  200  includes central processing unit (CPU)  210 , transceiver  220 , communication interface  225 , communication infrastructure  230 , memory  235 , and antenna  250 . Memory  235  may include random access memory (RAM) and/or cache, and may include control logic (e.g., computer software) and/or data. CPU  210  together with instructions stored in memory  235  performs operations enabling a wireless system  200  of a system  100  implementing a mobile AP station. Transceiver  220  transmits and receives communications signals that support mobile AP station functions according to some embodiments, and may be coupled to antenna  250 . Communication interface  225  allows system  200  to communicate with other devices that may be wired and/or wireless. Communication infrastructure  230  may be a bus. Antenna  250  may include one or more antennas that may be the same or different types. 
     Some embodiments enable a mobile AP station to implement a Target Wake Time (TWT) protocol as a TWT responder, and utilize TWT Responder Power Save Mode features. Using the TWT protocol enables the mobile AP station to remain in the always-on soft AP mode and concurrently maintain a connection with an AP as a station in an infrastructure mode. For example, a mobile AP station may utilize the TWT protocol to: set an individual TWT service period for an associated station to access the medium (e.g., WLAN medium access); and/or arrange for the mobile AP station to go to sleep outside of a TWT service period. When a mobile AP station goes to sleep (e.g., enters a power save mode) transmissions from unassociated stations may be missed. To avoid missing transmissions from unassociated stations, a mobile AP station may stay active for some time after a beacon or selected beacons. The stay active time may be called a wake window for unassociated stations. During a wake window for unassociated stations, the mobile AP station is active and may receive communications from stations such as 802.11 legacy devices and/or TWT-capable devices. The duration of the wake window for unassociated stations can be dynamically adjusted based on a number of stations currently associated with the mobile AP station. For example, when no stations are associated with the mobile AP station, the wake window for unassociated stations can be set to a longer time than when a station is associated. The longer time may increase the chances of unassociated stations being able to join a network of the mobile AP station. Conversely, when many stations are associated with the mobile AP station, the wake window for unassociated stations may be reduced to limit congestion, for example. 
     Since 802.11 legacy devices do not support TWT capabilities, when an 802.11 legacy device associates with the mobile AP station, the mobile device exits mobile AP station functions. 
     In addition to a wake window for unassociated stations, a mobile AP station may set up a broadcast TWT schedule and advertise a broadcast TWT service period in a beacon to help TWT-capable devices conserve power usage. For example, TWT-capable devices that receive the beacon can remain asleep until the broadcast TWT service period. The TWT-capable devices may wake during the broadcast TWT to associate with the mobile AP station. Thus, a TWT-capable device may remain asleep and may not have to contend with 802.11 legacy devices during a wake window for unassociated station time period. 
       FIG. 3  illustrates an example operation  300  of a mobile AP station with no associated devices, according to some embodiments of the disclosure. As a convenience and not a limitation,  FIG. 3  may be described with regard to elements of  FIG. 1 . Operation  300  may represent the operation of mobile AP station  150  when devices  120   b - 120   e  are not associated with mobile AP station  150 , and mobile AP station  150  transmits infrastructure traffic to AP  110 . Operation  300  includes beacons  310  and  340 , wake windows for unassociated stations  315  and  345 , infrastructure modes  320  and  330 , and sleep mode  325  and  335 . 
     During operation, mobile AP station  150  operates in an always-on soft AP mode and transmits beacon  310 . Subsequent to transmitting beacon  310 , mobile AP station  150  remains active for a duration of wake window for unassociated stations  315  to give 802.11 legacy devices as well as unassociated TWT-capable devices an opportunity to associate with mobile AP station  150 . Mobile AP station  150  may switch to infrastructure mode  320  and transmit and/or receive communications from AP  110 , then go into a power save mode at sleep mode  325 . After sleep mode  325 , mobile AP station  150  may wake to exchange infrastructure traffic again with AP  110  during infrastructure mode  330 , and return to sleep at sleep mode  335 . At the start of the next period, mobile AP station  150  transmits beacon  340  and may dynamically change a duration of wake windows for unassociated stations  345 , based on a number of associated stations  120 . In this example, no stations  120  are associated so mobile AP station  150  may remain awake longer to allow unassociated stations  120  to join a network that includes mobile AP station  150 . Thus, mobile AP station  150  may extend wake window for unassociated stations  345  to be longer than wake window for unassociated stations  315 . 
       FIG. 4  illustrates an example operation  400  of a mobile AP station with associated devices, according to some embodiments of the disclosure. As a convenience and not a limitation,  FIG. 4  may be described with regard to elements of  FIGS. 1 and 3 . Operation  400  may represent the operation of mobile AP station  150  when devices  120   b - 120   d  are associated with mobile AP station  150 , and mobile AP station  150  is able to switch back to infrastructure mode to transmit infrastructure traffic to AP  110 . Operation  400  includes beacons  410  and  445 , wake windows for unassociated stations  415  and  450 , infrastructure modes  420  and  430 , TWT for TWT-capable associated stations  425  and  435 , and sleep mode  440 . Mobile AP station  150  operates in an always-on soft AP mode and transmits beacon  410 . Mobile AP station  150  remains awake for the duration of wake window for unassociated stations  415 , and switches to infrastructure mode  420  to exchange infrastructure traffic with AP  110 . Subsequently, during TWT for TWT-capable associated stations  425 , mobile AP station  150  may exchange soft AP traffic with TWT-capable associated stations, such as stations  120   b - 120   d . For example, stations  120   b - 120   d  may contend for access or exchange soft AP traffic as allocated, during TWT for TWT-capable associated stations  425 . Mobile AP station  150  may switch to infrastructure mode  430  and exchange infrastructure traffic with AP  110 , and during TWT for TWT-capable associated stations  435 , exchange soft AP traffic with one or more of associated stations  120   b - 120   d . Mobile AP station  150  may enter a power save mode during sleep mode  440 . In the next period, mobile AP station  150  may transmit beacon  445  and implement wake window for unassociated stations  450 . Mobile AP station may dynamically adjust the active time after beacon  445  based at least on the number of associated stations  120   b - 120   d . For example, the time for wake window for unassociated stations  450  may be reduced compared to wake window for unassociated stations  415 . 
       FIG. 5  illustrates an example operation  500  of a mobile AP station with unassociated TWT-capable devices, according to some embodiments of the disclosure. As a convenience and not a limitation,  FIG. 5  may be described with regard to elements of  FIGS. 1, 3, and 4 . Operation  500  may represent the operation of mobile AP station  150  when devices  120   b - 120   d  are associated with mobile AP station  150 , device  120   e  is a TWT-capable device that is not associated with mobile AP station  150 , and mobile AP station  150  is able to switch back to infrastructure mode to transmit infrastructure traffic to AP  110 . Operation  500  includes beacons  510  and  550 , wake windows for unassociated stations  515  and  555 , infrastructure mode  520 , and sleep modes  530  and  549 . Mobile AP station  150  may group associated stations  120   b - 120   d  to different TWT periods to reduce contention in a TWT period. In operation  500 , stations  120   b  and  120   c  may be assigned to TWT for associated stations  425  and station  120   d  may be assigned to TWT for associated station  535 . Mobile AP station  150  may arrange a broadcast TWT schedule that is advertised in beacon  510 . Unassociated TWT-capable stations like station  120   e  may receive the broadcast TWT schedule and remain asleep until a broadcast TWT service period such as TWT for unassociated TWT-capable stations  545 . 
     In operation  500 , Mobile AP station  150  operates in an always-on soft AP mode and transmits beacon  510 . Mobile AP station  150  remains awake for the duration of wake window for unassociated stations  515 , and switches to infrastructure mode  520  to exchange infrastructure traffic with AP  110 . Subsequently, during TWT for TWT-capable associated stations  525 , mobile AP station  150  may exchange soft AP traffic with TWT-capable associated stations  120   b  and  120   c . For example, stations  120   b  and  120   c  may contend for access or exchange soft AP traffic as allocated, during TWT for TWT-capable associated stations  525 . Mobile AP station  150  may enter and remain in a power save mode for sleep mode  530 , and then exchange soft AP traffic during TWT for TWT-capable associated stations  535  with associated station  120   d . Mobile AP station  150  may enter and remain in a power save mode during sleep mode  540 . At TWT for unassociated TWT-capable stations  545 , mobile AP station  150  may remain active to enable unassociated TWT-capable stations like station  120   e  to join the network of mobile AP station  150 . 
     Based on the activity in the period such as station  120   e  associating with mobile AP station  150 , mobile AP station  150  may adjust the time period of wake window for unassociated stations  555  and/or a duration of the next TWT for unassociated TWT-capable stations time period. Mobile AP station  150  may also assign station  120   e  to TWT for station  525  or  535 . Mobile AP station  150  may also adjust the TWT schedule as well as a duration of the infrastructure mode based on any/all of: a number of stations associated with mobile AP station  150 , a soft AP traffic load of the associated stations  120  associated with mobile AP station  150 , and/or an infrastructure traffic load of mobile AP station  150  and AP  110 . 
       FIG. 6  illustrates an example method  600  for a wireless system supporting a mobile AP station, according to some embodiments of the disclosure. As a convenience and not a limitation,  FIG. 6  may be described with regard to elements of  FIGS. 1-5 . Method  600  may represent the operation of mobile AP station  150  of  FIG. 1  performing always-on soft AP functions and also being able to switch back to infrastructure mode to transmit infrastructure traffic to AP  110  as a station. Method  600  may also be performed by system  200  of  FIG. 2  or computer system  1000  of  FIG. 10 . 
     At  605 , system  200  implements a TWT protocol as a TWT responder, and utilizes TWT Responder Power Save Mode features. Using the TWT protocol enables system  200  to remain in the always-on soft AP mode and concurrently maintain a connection with an AP as a station in an infrastructure mode. For example, mobile AP station  150  may utilize the TWT protocol to: set an individual TWT service period for one or more associated TWT-capable stations  120  to access the WLAN medium via communications  155   a - 155   c , set a time for transmitting infrastructure data to AP  110  as a station via communications  140   b , set a time for unassociated devices to communicate with mobile AP station  150 , set a time to sleep, and/or set a time to remain awake. Mobile AP station  150  may set up individual TWT with each associated station by: setting and transmitting a specific field in a beacon that indicates that stations are to initiate a TWT setup request with the mobile AP station  150 ; and/or if the mobile AP station  150  has not received a TWT setup request from an associated station  120 , the mobile AP station may set up an unsolicited TWT with a station  120 . 
     In an embodiment, system  200  transmits a high efficiency (HE) Operation Element in a beacon, that instructs receiving stations to request setting up a TWT with mobile AP station  150 . In particular, the HE Operation Element includes a TWT Required Field set to “1.” As an example, CPU  210  together with instructions stored in memory  235  may set the TWT Required Field of HE Operation Element to “1” enabling system  200  (e.g., mobile AP station  150 ) to transmit a beacon that includes the HE Operation Element with a TWT Required field set to “1” using the transceiver  220 . 
     At  610 , system  200  sets up a wake window for unassociated station, including a number and duration that occur after one or more select beacons. Examples of a wake window for unassociated station include  315  and  345  of  FIG. 3, 415 and 450  of  FIG. 4, and 515 and 555  of  FIG. 5 . The number and duration of wake window for unassociated stations may be dynamically updated based at least on a number of stations that associate with system  200  (e.g., mobile AP station  150 .) For example, when there are no stations or few stations associated with mobile AP station  150 , then system  200  may increase a number of and/or duration of wake windows for unassociated stations to allow new unassociated stations  120  to join a network of mobile AP station  150 . When there are many stations associated with mobile AP station  150 , then system  200  may decrease a number of and/or duration of wake windows for unassociated stations to control the number of new unassociated stations  120  that may join the network of mobile AP station  150 . A wake window for unassociated station may be scheduled adjacent to a beacon or specific beacons (e.g.,  310  and  340 ,  410  and  445 , and/or  510  and  550 .) 
     At  620 , system  200  may set up a broadcast TWT schedule advertised in a beacon, where the TWT schedule includes a number and duration of service periods for TWT for unassociated TWT-capable stations. TWT-capable devices that receive the beacon can remain asleep, avoid contention with devices during a wake window for unassociated station  515  of  FIG. 5 , and wake to associate with mobile AP station  150  at TWT for unassociated TWT-capable stations  545  of  FIG. 5 . 
     At  625 , system  200  determines a schedule for a number and duration of infrastructure mode periods. Concurrent with maintaining an association with a station (e.g., station  120   b ) in an always-on soft AP mode, mobile AP station  150  can switch back to infrastructure mode as a station and exchange infrastructure traffic with AP  110 . Based on the load and the time critical aspects infrastructure traffic, mobile AP station  150  determines a number and duration of periods for operating as a station to communicate with AP  110 . Examples of infrastructure modes include  320  and  330  of  FIG. 3, 420 and 430  of  FIG. 4, and 520  of  FIG. 5 . 
     At  630 , system  200  operates according to the set ups, TWT schedule, and infrastructure mode duration described above. Examples of the operations are described in  FIGS. 3-5 . 
     At  635 , system  200  associates with one or more stations  120 . 
     At  645 , system  200  schedules a TWT or an unsolicited TWT for a TWT-capable station. For example, in response to receiving the beacon, station  120   c  may initiate a TWT setup request and system  200  responds with an assignment of a TWT service period. Example assignments include  425  and  435  of  FIG. 4 and 525 and 535  of  FIG. 5 . If system  200  does not receive a TWT setup request from the TWT-capable station (e.g., station  120   d ) system  200  may schedule an unsolicited TWT for station  120   d , e.g.,  535  of  FIG. 5 . 
     At  650 , system  200  informs associated stations that mobile AP station  150  is not available outside of the scheduled TWT. Mobile AP station  150  may arrange to go to sleep outside of a scheduled TWT service period (e.g., sleep modes  530  and  540  of  FIG. 5 .) There may be less stations associated with mobile AP station  150  than AP  110 , thus after TWT schedules are arranged, mobile AP station  150  may have time to go to sleep outside of the scheduled TWT service periods. To arrange to go to sleep outside of a TWT service period, mobile AP station  150  may set TWT Responder Power Save bit during TWT setup. Implementing TWT responder power save mode features enable mobile AP station  150  to reduce power consumption. As an example, system  200  may transmit to an associated station  120  a TWT Element that includes a TWT Responder Power Save field set to “1.” CPU  210  together with instructions stored in memory  235  (e.g., a driver) may set the TWT Responder Power Save field of TWT Element to “1” enabling system  200  (e.g., mobile AP station  150 ) to transmit to an associated station, a TWT Element that includes a TWT Responder Power Save field set to “1.” Thus, station  120  will be aware that mobile AP station  150  may go to sleep outside of a TWT service period. Consequently, associated TWT-capable stations  120  may not communicate with mobile AP station  150  outside of their TWT service period. Using the HE Operation Element with the TWT Required Field set to “1” and the TWT Element that includes a TWT Responder Power Save field set to “1,” system  200  can set up a TWT with each associated station and may go to sleep outside of a scheduled TWT service period. 
     At  655 , system  200  dynamically adjusts TWT schedule, infrastructure mode duration, broadcast TWT schedule, and/or wake window for unassociated stations. For example, the TWT parameters and durations of time may be adjusted based on a number of stations associated with mobile AP station  150 , a traffic load between associated stations  120   b - 120   d  and mobile AP station  150 , and/or the infrastructure traffic load between the mobile AP station  150  and AP  110 . In addition, system  200  dynamically adjusts a number and duration of service periods for wake windows for unassociated stations based at least on the number of stations  120  associated with system  200  (e.g., mobile AP station.) Method  600  returns to  630  and operates accordingly. 
     Various embodiments can be implemented, for example, using one or more computer systems, such as computer system  700  shown in  FIG. 7 . Computer system  700  can be any well-known computer capable of performing the functions described herein such as devices  110 ,  120 , or  150  of  FIG. 1 . Computer system  700  includes one or more processors (also called central processing units, or CPUs), such as a processor  704 . Processor  704  is connected to a communication infrastructure  706  (e.g., a bus.) Computer system  700  also includes user input/output device(s)  703 , such as monitors, keyboards, pointing devices, etc., that communicate with communication infrastructure  706  through user input/output interface(s)  702 . Computer system  700  also includes a main or primary memory  708 , such as random access memory (RAM). Main memory  708  may include one or more levels of cache. Main memory  708  has stored therein control logic (e.g., computer software) and/or data. 
     Computer system  700  may also include one or more secondary storage devices or memory  710 . Secondary memory  710  may include, for example, a hard disk drive  712  and/or a removable storage device or drive  714 . Removable storage drive  714  may be a floppy disk drive, a magnetic tape drive, a compact disk drive, an optical storage device, tape backup device, and/or any other storage device/drive. 
     Removable storage drive  714  may interact with a removable storage unit  718 . Removable storage unit  718  includes a computer usable or readable storage device having stored thereon computer software (control logic) and/or data. Removable storage unit  718  may be a floppy disk, magnetic tape, compact disk, DVD, optical storage disk, and/any other computer data storage device. Removable storage drive  714  reads from and/or writes to removable storage unit  718  in a well-known manner. 
     According to some embodiments, secondary memory  710  may include other means, instrumentalities or other approaches for allowing computer programs and/or other instructions and/or data to be accessed by computer system  700 . Such means, instrumentalities or other approaches may include, for example, a removable storage unit  722  and an interface  720 . Examples of the removable storage unit  722  and the interface  720  may include a program cartridge and cartridge interface (such as that found in video game devices), a removable memory chip (such as an EPROM or PROM) and associated socket, a memory stick and USB port, a memory card and associated memory card slot, and/or any other removable storage unit and associated interface. 
     Computer system  700  may further include a communication or network interface  724 . Communication interface  724  enables computer system  700  to communicate and interact with any combination of remote devices, remote networks, remote entities, etc. (individually and collectively referenced by reference number  728 ). For example, communication interface  724  may allow computer system  700  to communicate with remote devices  728  over communications path  726 , which may be wired and/or wireless, and which may include any combination of LANs, WANs, the Internet, etc. Control logic and/or data may be transmitted to and from computer system  700  via communication path  726 . 
     The operations in the preceding embodiments can be implemented in a wide variety of configurations and architectures. Therefore, some or all of the operations in the preceding embodiments may be performed in hardware, in software or both. In some embodiments, a tangible, non-transitory apparatus or article of manufacture includes a tangible, non-transitory computer useable or readable medium having control logic (software) stored thereon is also referred to herein as a computer program product or program storage device. This includes, but is not limited to, computer system  700 , main memory  708 , secondary memory  710  and removable storage units  718  and  722 , as well as tangible articles of manufacture embodying any combination of the foregoing. Such control logic, when executed by one or more data processing devices (such as computer system  700 ), causes such data processing devices to operate as described herein. 
     Based on the teachings contained in this disclosure, it will be apparent to persons skilled in the relevant art(s) how to make and use embodiments of the disclosure using data processing devices, computer systems and/or computer architectures other than that shown in  FIG. 7 . In particular, embodiments may operate with software, hardware, and/or operating system implementations other than those described herein. 
     It is to be appreciated that the Detailed Description section, and not the Summary and Abstract sections, is intended to be used to interpret the claims. The Summary and Abstract sections may set forth one or more but not all exemplary embodiments of the disclosure as contemplated by the inventor(s), and thus, are not intended to limit the disclosure or the appended claims in any way. 
     While the disclosure has been described herein with reference to exemplary embodiments for exemplary fields and applications, it should be understood that the disclosure is not limited thereto. Other embodiments and modifications thereto are possible, and are within the scope and spirit of the disclosure. For example, and without limiting the generality of this paragraph, embodiments are not limited to the software, hardware, firmware, and/or entities illustrated in the figures and/or described herein. Further, embodiments (whether or not explicitly described herein) have significant utility to fields and applications beyond the examples described herein. 
     Embodiments have been described herein with the aid of functional building blocks illustrating the implementation of specified functions and relationships thereof. The boundaries of these functional building blocks have been arbitrarily defined herein for the convenience of the description. Alternate boundaries can be defined as long as the specified functions and relationships (or equivalents thereof) are appropriately performed. In addition, alternative embodiments may perform functional blocks, steps, operations, methods, etc. using orderings different from those described herein. 
     References herein to “one embodiment,” “an embodiment,” “an example embodiment,” or similar phrases, indicate that the embodiment described may include a particular feature, structure, or characteristic, but every embodiment may not necessarily include the particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with an embodiment, it would be within the knowledge of persons skilled in the relevant art(s) to incorporate such feature, structure, or characteristic into other embodiments whether or not explicitly mentioned or described herein. 
     The breadth and scope of the disclosure should not be limited by any of the above-described exemplary embodiments, but should be defined only in accordance with the following claims and their equivalents.

Metadata:
Filing Date: 20190226
Publication Date: 20210608
Grant Date: 20210608
Priority Date: 20180629
Inventors: LI, GUOQING
BAHINI, Dagbegnon H.
KUMAR, RAJNEESH
Assignee: APPLE INC
CPC Classifications: [{"code": "H04W52/0216", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04W72/52", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04W72/23", "inventive": true, "first": false, "tree": "[]"}, {"code": "Y02D30/70", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04W72/1263", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04W76/28", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04W72/1263", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04W88/08", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04W52/0216", "inventive": true, "first": true, "tree": "[]"}, {"code": "H04W52/0206", "inventive": true, "first": true, "tree": "[]"}, {"code": "H04W52/0206", "inventive": true, "first": true, "tree": "[]"}, {"code": "Y02D30/70", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04W52/0206", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04W52/0216", "inventive": true, "first": false, "tree": "[]"}, {"code": "Y02D30/70", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04W52/0216", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04W76/28", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04W72/1252", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04W88/08", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04W72/1263", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04W72/1289", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04W52/0206", "inventive": true, "first": true, "tree": "[]"}]
Family ID: 66810719