PATENT DOCUMENT

Publication Number: US-11877348-B2
Application Number: US-202217571304-A
Country: US
Kind Code: B2

Title: Receive operation mode indication for power save

Abstract:
Embodiments described herein relate to a system and method for providing flexible receiver configuration in wireless communication systems, such as 802.11 WLAN systems. In one embodiment, a wireless device may transmit a first data frame including first configuration information specifying a first configuration of the receiver to notify a remote device that the wireless device intends to configure its receiver according to the first configuration. After receiving an acknowledgement frame confirming the first configuration information, the wireless device may configure the receiver according to the first configuration. In another embodiment, a wireless device may receive a first data frame including first configuration information and further including a request that the wireless device configure its receiver according to the first configuration. In response, the wireless device may configure the receiver according to the first configuration. In either case, the wireless device may receive subsequent communications according to the first configuration.

Claims:
What is claimed is: 
     
       1. A method of managing a wireless communication mode of a wireless device, the method comprising:
 by the wireless device:
 receiving a first data frame from a remote device, the first data frame including first configuration information specifying a first configuration of a receiver of the remote device; 
 transmitting to the remote device a first acknowledgement frame according to a format that is receivable by the remote device if the receiver is configured according to a second configuration, wherein the first acknowledgement frame includes a confirmation of the first configuration information; and 
 transmitting to the remote device a second data frame according to a format that is receivable by the remote device if the receiver is configured according to the first configuration, wherein the transmitting the second data frame occurs after the transmitting the first acknowledgement frame. 
 
 
     
     
       2. The method of  claim 1 , wherein the first configuration information includes at least one of an indication of a channel width of the receiver and an indication of a number of active receive spatial streams of the receiver. 
     
     
       3. The method of  claim 1 , wherein the first configuration information is included in a header of the first data frame, and wherein the confirmation of the first configuration information is included in a header of the first acknowledgement frame. 
     
     
       4. The method of  claim 3 , wherein the header of the first data frame and the header of the first acknowledgement frame include media access control (MAC) headers. 
     
     
       5. The method of  claim 1 , wherein the second data frame includes second configuration information specifying a third configuration of the receiver, the method further comprising:
 by the wireless device:
 receiving a second acknowledgement frame confirming the second configuration information; and 
 transmitting to the remote device a third data frame according to a format that is receivable by the remote device if the receiver is configured according to the third configuration, wherein the transmitting the third data frame occurs after the receiving the second acknowledgement frame. 
 
 
     
     
       6. The method of  claim 5 , wherein each of the first configuration information and the second configuration information includes at least one of an indication of a channel width of the receiver and an indication of a number of active receive spatial streams of the receiver. 
     
     
       7. The method of  claim 6 ,
 wherein the first data frame further includes an indication that the first configuration information includes a notice from the remote device that the receiver will be configured according to the first configuration; and 
 wherein the second data frame further includes an indication that the second configuration information includes a request from the wireless device that the receiver be configured according to the third configuration. 
 
     
     
       8. A wireless communication device comprising:
 a radio transceiver; and 
 a processing element operably coupled to the radio transceiver, wherein the processing element is configured to cause the wireless communication device to:
 receive, via the radio transceiver, a first data frame from a remote device, the first data frame including first configuration information specifying a first configuration of a receiver of the remote device; 
 transmit to the remote device, via the radio transceiver, a first acknowledgement frame according to a format that is receivable by the remote device if the receiver is configured according to a second configuration, wherein the first acknowledgement frame includes a confirmation of the first configuration information; and 
 transmit to the remote device, via the radio transceiver, a second data frame according to a format that is receivable by the remote device if the receiver is configured according to the first configuration, wherein the transmitting the second data frame occurs after the transmitting the first acknowledgement frame. 
 
 
     
     
       9. The wireless communication device of  claim 8 , wherein the first configuration information includes at least one of an indication of a channel width of the receiver and an indication of a number of active receive spatial streams of the receiver. 
     
     
       10. The wireless communication device of  claim 8 , wherein the first configuration information is included in a header of the first data frame, and wherein the confirmation of the first configuration information is included in a header of the first acknowledgement frame. 
     
     
       11. The wireless communication device of  claim 10 , wherein the header of the first data frame and the header of the first acknowledgement frame include media access control (MAC) headers. 
     
     
       12. The wireless communication device of  claim 8 , wherein the second data frame includes second configuration information specifying a third configuration of the receiver, wherein the processing element is configured to further cause the wireless communication device to:
 receive, via the radio transceiver, a second acknowledgement frame confirming the second configuration information; and 
 transmit to the remote device, via the radio transceiver, a third data frame according to a format that is receivable by the remote device if the receiver is configured according to the third configuration, wherein the transmitting the third data frame occurs after the receiving the second acknowledgement frame. 
 
     
     
       13. The wireless communication device of  claim 12 , wherein each of the first configuration information and the second configuration information includes at least one of an indication of a channel width of the receiver and an indication of a number of active receive spatial streams of the receiver. 
     
     
       14. The wireless communication device of  claim 13 ,
 wherein the first data frame further includes an indication that the first configuration information includes a notice from the remote device that the receiver will be configured according to the first configuration; and 
 wherein the second data frame further includes an indication that the second configuration information includes a request from the wireless communication device that the receiver be configured according to the third configuration. 
 
     
     
       15. A non-transitory computer readable memory medium storing software instructions that, when executed by a wireless communication device, cause the wireless communication device to:
 receive, according to a first configuration of a receiver of the wireless communication device, a first data frame of a plurality of aggregated data frames, the first data frame including first configuration information specifying a second configuration of the receiver; 
 configure the receiver according to the second configuration in response to receiving the first data frame; and 
 receive, according to the second configuration of the receiver, a second data frame of the plurality of aggregated data frames. 
 
     
     
       16. The non-transitory computer readable memory medium of  claim 15 , wherein the first configuration information includes at least one of an indication of a channel width of the receiver and an indication of a number of active receive spatial streams of the receiver. 
     
     
       17. The non-transitory computer readable memory medium of  claim 15 , wherein the first configuration information is included in a header of the first data frame. 
     
     
       18. The non-transitory computer readable memory medium of  claim 17 , wherein the header of the first data frame includes a media access control (MAC) header. 
     
     
       19. The non-transitory computer readable memory medium of  claim 15 , wherein the software instructions, when executed by the wireless communication device, further cause the wireless communication device to:
 transmit to a remote device, an acknowledgement frame acknowledging receipt of the plurality of aggregated data frames. 
 
     
     
       20. The non-transitory computer readable memory medium of  claim 15 , wherein the software instructions, when executed by the wireless communication device, further cause the wireless communication device to:
 transmit a mode request frame including a request to initiate a configuration control mode; and 
 receive a mode response frame confirming initiation of the configuration control mode, wherein configuring the receiver according to the second configuration is further in response to receiving the mode response frame.

Description:
PRIORITY INFORMATION 
     This application is a continuation of U.S. patent application Ser. No. 14/794,011, entitled “Receive Operation Mode Indication for Power Save”, filed Jul. 8, 2015, which claims priority to U.S. provisional patent application Ser. No. 62/023,690, entitled “Receive Operation Mode Indication for Power Save,” filed Jul. 11, 2014, each of which is hereby incorporated by reference in its entirety as though fully and completely set forth herein. 
     The claims in the instant application are different than those of the parent application or other related applications. The Applicant therefore rescinds any disclaimer of claim scope made in the parent application or any predecessor application in relation to the instant application. The Examiner is therefore advised that any such previous disclaimer and the cited references that it was made to avoid, may need to be revisited. Further, any disclaimer made in the instant application should not be read into or against the parent application or other related applications. 
    
    
     TECHNICAL FIELD 
     The present application relates to wireless devices, and more particularly to providing improved power management in Wireless LAN systems. 
     DESCRIPTION OF THE RELATED ART 
     Wireless communication systems are rapidly growing in usage. Further, wireless communication technology has evolved from voice-only communications to also include the transmission of data, such as Internet and multimedia content. A popular short/intermediate range wireless communication standard is wireless local area network (WLAN). Most modern WLANs are based on the IEEE 802.11 standard and are marketed under the Wi-Fi brand name. WLAN networks link one or more devices to a wireless access point, which in turn provides connectivity to the wider Internet. 
     In 802.11 systems, devices that wirelessly connect to each other are referred to as “stations” or STA for short. Wireless stations can be either wireless access points or clients. Access points (APs), also referred to as wireless routers, act as base stations for the wireless network. APs transmit and receive radio frequency signals for communication with wireless client devices. APs also typically couple to the Internet in a wired fashion. Wireless clients operating on an 802.11 network can be any of various devices such as laptops, tablet devices, smart phones, or fixed devices such as desktop computers. Wireless client devices are referred to herein as stations, STA devices, or simply as “STA”. Wireless client devices are also referred to herein as mobile devices. 
     Since in most instances the devices communicating on a WLAN are mobile, battery-operated devices, power management is an important consideration. The IEEE 802.11 standards define a spatial multiplexing (SM) power save feature to allow a STA to operate with only one active receive chain for a significant portion of time for the purpose of power conservation. However, that feature suffers from several drawbacks, including poor media access control (MAC) efficiency due to required control frames, and inflexibility in configuring a receiver. 
     Therefore, improvements are desired in wireless communication systems. In particular, it would be desirable to provide improvements with respect to reduced power consumption and/or reduced latency in WLAN systems. 
     SUMMARY 
     Embodiments described herein relate to a system and method for providing flexible receiver configuration in wireless communication systems, such as 802.11 WLAN systems. 
     In some embodiments, a method for reconfiguring a receiver in a wireless device, such as a mobile device or an access point, is presented. The wireless device may transmit a first data frame. The first data frame may include first configuration information specifying a first configuration of the receiver. For example, the first configuration information may include at least one of an indication of a channel width of the receiver and an indication of a number of active receive spatial streams of the receiver. The first configuration information may, for example, be included in a header of the first data frame, such as a MAC header. The wireless device may receive a first acknowledgement frame according to a second configuration of the receiver. The first acknowledgement frame may confirm the first configuration information. For example, the first configuration information may be included in a header of the first acknowledgement frame, such as a MAC header. In response to the receiving the first acknowledgement frame, the wireless device may configure the receiver according to the first configuration. The wireless device may then receive a second data frame according to the first configuration. 
     The second data frame may, in some scenarios, include second configuration information specifying a third configuration of the receiver. The wireless device may transmit a second acknowledgement frame confirming the second configuration information. In response to the receiving the second data frame, the wireless device may configure the receiver according to the third configuration. The wireless device may then receive a third data frame according to the third configuration. 
     The first data frame may further include an indication that the first configuration information includes a notice from the wireless device that the receiver will be configured according to the first configuration. The second data frame may further include an indication that the second configuration information includes a request from a sender of the second data frame that the receiver be configured according to the third configuration. 
     In other embodiments, a wireless communication device is disclosed. The wireless communication device may include a radio, including a receiver, and a processing element operably coupled to the radio. The processing element may be configured to cause the wireless communication device to perform functions similar to the method steps summarized above. 
     In other embodiments, a non-transitory computer-readable memory medium is disclosed, the non-transitory computer-readable memory medium storing program instructions that, when executed at a wireless communication device, cause the wireless communication device to perform functions similar to the method steps summarized above. 
     This Summary is provided for purposes of summarizing some exemplary embodiments to provide a basic understanding of aspects of the subject matter described herein. Accordingly, the above-described features are merely examples and should not be construed to narrow the scope or spirit of the subject matter described herein in any way. Other features, aspects, and advantages of the subject matter described herein will become apparent from the following Detailed Description, Figures, and Claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       A better understanding of the present disclosure can be obtained when the following detailed description of the embodiments is considered in conjunction with the following drawings. 
         FIG.  1    illustrates an example WLAN communication system, according to some embodiments; 
         FIG.  2    illustrates an example simplified block diagram of a WLAN Access Point (AP), according to some embodiments; 
         FIG.  3    illustrates an example simplified block diagram of a mobile device, according to some embodiments; 
         FIG.  4 A  illustrates a timeline demonstrating use by a wireless device of configuration information for signaling a configuration of its own receiver, according to some scenarios; 
         FIG.  4 B  illustrates a timeline demonstrating use by a wireless device of configuration information for signaling a configuration of a receiver of a remote wireless device, according to some scenarios; 
         FIGS.  5 A and  5 B  are flowchart diagrams illustrating exemplary methods for reconfiguring a receiver in a wireless device, according to some scenarios; 
         FIG.  6    illustrates a timeline demonstrating use by a wireless device of configuration information for instructing a configuration of a receiver of a remote device, according to some scenarios; 
         FIG.  7    is a flowchart diagram illustrating an exemplary method for reconfiguring a receiver in a wireless device, according to some scenarios. 
     
    
    
     While the embodiments described in this disclosure may be susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and are herein described in detail. It should be understood, however, that the drawings and detailed description thereto are not intended to limit the embodiments to the particular form disclosed, but on the contrary, the intention is to cover all modifications, equivalents and alternatives falling within the spirit and scope of the appended claims. 
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
     Acronyms 
     The following acronyms are used in the present disclosure.
         AP: Access Point   A-PPDU: Aggregated PPDU   CW: Channel Width   MAC: Media Access Control   NSS: Number of Spatial Streams   PLCP: Physical Layer Convergence Protocol   PPDU: PLCP Protocol Data Unit   PSDU: PLCP Service Data Unit   RAT: Radio Access Technology   RX: Receive   RXCW: Receive Channel Width   RXMR: Receive Mode Request   RXNSS: Receive Number of Spatial Streams   RXOM: Receive Operating Mode   SM: Spatial Multiplexing   STA: Station device, such as a client mobile device   TX: Transmit   WLAN: Wireless Local Area Network       

     Terms 
     The following is a glossary of terms used in the present application: 
     Memory Medium—Any of various types of memory devices or storage devices. The term “memory medium” is intended to include an installation medium, e.g., a CD-ROM, floppy disks, or tape device; a computer system memory or random access memory such as DRAM, DDR RAM, SRAM, EDO RAM, Rambus RAM, etc.; a non-volatile memory such as a Flash, magnetic media, e.g., a hard drive, or optical storage; registers, or other similar types of memory elements, etc. The memory medium may include other types of memory as well or combinations thereof. In addition, the memory medium may be located in a first computer system in which the programs are executed, or may be located in a second different computer system which connects to the first computer system over a network, such as the Internet. In the latter instance, the second computer system may provide program instructions to the first computer for execution. The term “memory medium” may include two or more memory mediums which may reside in different locations, e.g., in different computer systems that are connected over a network. The memory medium may store program instructions (e.g., embodied as computer programs) that may be executed by one or more processors. 
     Carrier Medium—a memory medium as described above, as well as a physical transmission medium, such as a bus, network, and/or other physical transmission medium that conveys signals such as electrical, electromagnetic, or digital signals. 
     Computer System—any of various types of computing or processing systems, including a personal computer system (PC), mainframe computer system, workstation, network appliance, Internet appliance, personal digital assistant (PDA), personal communication device, smart phone, television system, grid computing system, or other device or combinations of devices. In general, the term “computer system” can be broadly defined to encompass any device (or combination of devices) having at least one processor that executes instructions from a memory medium. 
     Mobile Device—any of various types of computer systems devices which are mobile or portable and which performs wireless communications using WLAN communication. Examples of mobile devices include mobile telephones or smart phones (e.g., iPhone™, Android™-based phones), and tablet computers such as iPad, Samsung Galaxy, etc. Various other types of devices would fall into this category if they include both cellular and WiFi communication capabilities, such as laptop computers (e.g., MacBook), portable gaming devices (e.g., Nintendo DS™, PlayStation Portable™, Gameboy Advance™, iPhone™), portable Internet devices, and other handheld devices, as well as wearable devices such as wrist-watches, headphones, pendants, earpieces, etc. In general, the term “mobile device” can be broadly defined to encompass any electronic, computing, and/or telecommunications device (or combination of devices) which is easily transported by a user and capable of wireless communication using WLAN. 
     Wireless Device—any of various types of computer systems devices which performs wireless communications using WLAN communications. As used herein, the term “wireless device” may refer to a mobile device, as defined above, or to a stationary device, such as a wireless base station. For example, a wireless device may be any type of wireless station of an 802.11 system, such as an access point (AP) or a client station (STA). 
     WLAN—The term “WLAN” has the full breadth of its ordinary meaning, and at least includes a wireless communication network or RAT that is serviced by WLAN access points and which provides connectivity through these access points to the Internet. Most modern WLANs are based on IEEE 802.11 standards and are marketed under the name “Wi-Fi”. A WLAN network is different from a cellular network. 
     Processing Element—refers to various elements or combinations of elements. Processing elements include, for example, circuits such as an ASIC (Application Specific Integrated Circuit), portions or circuits of individual processor cores, entire processor cores, individual processors, programmable hardware devices such as a field programmable gate array (FPGA), and/or larger portions of systems that include multiple processors. 
     Automatically—refers to an action or operation performed by a computer system (e.g., software executed by the computer system) or device (e.g., circuitry, programmable hardware elements, ASICs, etc.), without user input directly specifying or performing the action or operation. Thus, the term “automatically” is in contrast to an operation being manually performed or specified by the user, where the user provides input to directly perform the operation. An automatic procedure may be initiated by input provided by the user, but the subsequent actions that are performed “automatically” are not specified by the user, i.e., are not performed “manually”, where the user specifies each action to perform. For example, a user filling out an electronic form by selecting each field and providing input specifying information (e.g., by typing information, selecting check boxes, radio selections, etc.) is filling out the form manually, even though the computer system must update the form in response to the user actions. The form may be automatically filled out by the computer system where the computer system (e.g., software executing on the computer system) analyzes the fields of the form and fills in the form without any user input specifying the answers to the fields. As indicated above, the user may invoke the automatic filling of the form, but is not involved in the actual filling of the form (e.g., the user is not manually specifying answers to fields but rather they are being automatically completed). The present specification provides various examples of operations being automatically performed in response to actions the user has taken. 
       FIG.  1   —WLAN System 
       FIG.  1    illustrates an example WLAN system according to some embodiments. As shown, the exemplary WLAN system includes a mobile device  106  communicating over a wireless communication channel  142  with an Access Point (AP)  112 . The AP  112  may communicate via a wired or wireless communication channel  150  with one or more other electronic devices (not shown) and/or another network  152 , such as the Internet. Additional electronic devices, such as the remote device  154 , may communicate with components of the WLAN system via the network  152 . For example, the remote device  154  may be another mobile device. 
     The WLAN system may be configured to operate according to any of various communications standards, such as the various IEEE 802.11 standards. 
       FIG.  2   —Access Point Block Diagram 
       FIG.  2    illustrates an exemplary block diagram of an Access Point (AP)  112 . It is noted that the block diagram of the AP of  FIG.  2    is merely one example of a possible system. As shown, the AP  112  may include processor(s)  204  which may execute program instructions for the AP  112 . The processor(s)  204  may also be coupled to memory management unit (MMU)  240 , which may be configured to receive addresses from the processor(s)  204  and translate those addresses to locations in memory (e.g., memory  260  and read only memory (ROM)  250 ) or to other circuits or devices. 
     The AP  112  may include at least one network port  270 . The network port  270  may be configured to couple to a wired network and provide a plurality of devices, such as mobile devices  106 , access to the Internet. For example, the network port  270  (or an additional network port) may be configured to couple to a local network, such as a home network or an enterprise network. For example, the network port  270  may be an Ethernet port. The local network may provide connectivity to additional networks, such as the Internet. 
     The AP  112  may include at least one antenna  234 . The at least one antenna  234  may be configured to operate as a wireless transceiver and may be further configured to communicate with mobile device  106  via wireless communication circuitry  230 , which may include, e.g., a radio. The antenna  234  communicates with the wireless communication circuitry  230  via communication chain  232 . Communication chain  232  may include one or more receive chains, one or more transmit chains or both. The wireless communication circuitry  230  may be configured to communicate via Wi-Fi or WLAN, e.g., 802.11. The wireless communication circuitry  230  may be configured to communicate via various wireless communication technologies, including, but not limited to, LTE, LTE-A, GSM, WCDMA, CDMA2000, etc. 
     The AP  112  may be configured to implement part or all of the methods described herein, such as by reconfiguring a receiver included in the wireless communication circuitry  230  and/or the communication chain  232 , or by requesting or accommodating reconfiguration of a receiver of a remote wireless device, such as the mobile device  106 . For example, the processor(s)  204  of the AP  112  may be configured to implement part or all of the methods described herein, e.g., by executing program instructions stored on a memory medium (e.g., a non-transitory computer-readable memory medium). Alternatively, the processor  204  may be configured as a programmable hardware element, such as an FPGA (Field Programmable Gate Array), or as an ASIC (Application Specific Integrated Circuit), or a combination thereof. 
       FIG.  3   —Mobile Device Block Diagram 
       FIG.  3    illustrates an example simplified block diagram of a mobile device  106 . As shown, the mobile device  106  may include a system on chip (SOC)  300 , which may include portions for various purposes. The SOC  300  may be coupled to various other circuits of the mobile device  106 . For example, the mobile device  106  may include various types of memory (e.g., including NAND flash  310 ), a connector interface  320  (e.g., for coupling to a computer system, dock, charging station, etc.), the display  360 , cellular communication circuitry  330  such as for LTE, GSM, etc., and short range wireless communication circuitry  329  (e.g., Bluetooth™ and WLAN circuitry). The mobile device  106  may further include one or more smart cards  310  that include SIM (Subscriber Identity Module) functionality, such as one or more UICC(s) (Universal Integrated Circuit Card(s)) cards  310 . The cellular communication circuitry  330  may couple to one or more antennas, such as antennas  335  and  336  as shown. The short range wireless communication circuitry  329  may also couple to one or more antennas, such as antennas  337  and  338  as shown. Alternatively, the short range wireless communication circuitry  329  may couple to the antennas  335  and  336  in addition to, or instead of, coupling to the antennas  337  and  338 . The short range wireless communication circuitry  329  may include multiple receive chains and/or multiple transmit chains for receiving and/or transmitting multiple spatial streams, such as in a multiple-input multiple output (MIMO) configuration. 
     As shown, the SOC  300  may include processor(s)  302  which may execute program instructions for the mobile device  106  and display circuitry  304  which may perform graphics processing and provide display signals to the display  360 . The processor(s)  302  may also be coupled to memory management unit (MMU)  340 , which may be configured to receive addresses from the processor(s)  302  and translate those addresses to locations in memory (e.g., memory  306 , read only memory (ROM)  350 , NAND flash memory  310 ) and/or to other circuits or devices, such as the display circuitry  304 , cellular communication circuitry  330 , short range wireless communication circuitry  329 , connector interface (I/F)  320 , and/or display  360 . The MMU  340  may be configured to perform memory protection and page table translation or set up. In some embodiments, the MMU  340  may be included as a portion of the processor(s)  302 . 
     As noted above, the mobile device  106  may be configured to communicate wirelessly using one or more radio access technologies (RATs). The mobile device  106  may be configured to communicate according to a WLAN RAT for communication in a WLAN network, such as that shown in  FIG.  1   . The mobile device  106  may also be configured to communicate on other RATs, such as cellular RATs, as desired. 
     The mobile device  106  may include hardware and software components for implementing all of the methods described herein, such as by reconfiguring a receiver, e.g., included in the short range wireless communication circuitry  329 , or by requesting or accommodating reconfiguration of a receiver of a remote wireless device, such as the mobile device AP  112 . For example, the processor  302  of the mobile device  106  may be configured to implement part or all of the features described herein, e.g., by executing program instructions stored on a memory medium (e.g., a non-transitory computer-readable memory medium). Alternatively (or in addition), the processor  302  may be configured as a programmable hardware element, such as an FPGA (Field Programmable Gate Array), or as an ASIC (Application Specific Integrated Circuit). Alternatively (or in addition) the processor  302  of the mobile device  106 , in conjunction with one or more of the other components  300 ,  304 ,  306 ,  310 ,  320 ,  330 ,  335 ,  340 ,  350 ,  360  may be configured to implement part or all of the features described herein. 
     As used herein, the term “mobile device” may refer to a device such as the mobile device  106  described above. 
       FIGS.  4 A- 4 B —Receiver-Initiated Receiver Configuration 
     A wireless device, such as the mobile device  106  or the access point  112 , may configure its receiver to operate according to a plurality of configurations. For example, the wireless device may configure its receiver to operate with any of various channel widths. In some scenarios, the wireless device may select between channel widths of 20 MHz, 40 MHz, 80 MHz, or 160 MHz. As another example, the wireless device may configure its receiver to operate with any of various numbers of spatial streams. In some scenarios, the wireless device may select any integer number of spatial streams from 1 to 8. For example, this may be implemented by activating one receive chain for each of the selected number of spatial streams, while deactivating any remaining receive chains of the receiver. Thus, selecting a number of spatial streams may, in some cases, be synonymous with selecting a number of receive chains. 
     Selecting a smaller channel width and/or a lower number of spatial streams may allow a lower rate of power consumption by the receiver than selecting a larger channel width and/or a higher number of spatial streams. For example, selecting a lower number of spatial streams may allow hardware components of excess receive chains to be temporarily disabled. Thus, it may be preferable in some scenarios to select minimum configuration parameters sufficient to accommodate expected communication loads. Therefore, it may be advantageous to allow a wireless device to efficiently indicate to a remote device a preferred configuration of a receiver located either in the wireless device or in the remote device. For example, the preferred configuration may be based on information available to the wireless device regarding upcoming communication loads. 
       FIGS.  4 A and  4 B  illustrate timelines demonstrating use by a wireless device of configuration information for signaling a configuration of a receiver, according to two scenarios. Each of the  FIGS.  4 A and  4 B  demonstrates possible behavior of two wireless stations (STA 1  and STA 2 ), as time progresses from left to right. A current state of STA 1  is shown below each timeline. It should be appreciated that the timelines of  FIGS.  4 A and  4 B  include only details relevant to the explanation of the present embodiment, and may omit other details. For example, in some scenarios, STA 1  may transition at various times to other states, such as a Listen state, which are not illustrated in  FIGS.  4 A and  4 B . 
     Although the two wireless stations are discussed herein as client stations, this is not intended to be limiting, and it should be understood that the illustrated timelines may instead involve communications between other wireless stations, such as between a client station and an AP. For example, the illustrated timelines may be implemented in an identical fashion with an AP in place of STA 1  and/or STA 2 . For example, the illustrated procedures may be implemented by two devices including one or more of the mobile device  106  and the access point  112 . 
       FIG.  4 A  illustrates a timeline demonstrating use by a wireless device (STA 1 ) of configuration information for signaling a configuration of its own receiver, according to some scenarios. As shown in  FIG.  4 A , STA 1  may transmit to STA 2  a data frame  402 , while in a TX mode. The data frame  402  may include configuration information specifying a configuration according to which STA 1  intends to configure its receiver. For example, the configuration information may include an indication of a channel width and/or an indication of a number of spatial streams. In such an example, the configuration information may indicate that STA 1  intends to configure its receiver so as to receive signals having a channel width not greater than the indicated channel width and having a number of spatial streams not greater than the indicated number of spatial streams. 
     As illustrated in the example of  FIG.  4 A , the data frame  402  includes configuration information including an indication of a channel width of 40 MHz and an indication of a number of spatial streams of 2. 
     After transmitting the data frame  402 , STA 1  may transition to an RX state. However, STA 1  may defer configuration of its receiver according to the transmitted configuration information until after it receives a confirmation that STA 2  has received the configuration information. Therefore, when STA 1  enters the RX state, its receiver may be configured according to a previously negotiated configuration. As illustrated in the example of  FIG.  4 A , the receiver of STA 1  is configured to receive signals having a channel width not greater than 80 MHz and having a number of spatial streams not greater than 3. 
     In response to receiving the data frame  402 , STA 2  may transmit an acknowledgement frame  404 , which may confirm receipt by STA 2  of the configuration information included in the data frame  402 . For example, the acknowledgement frame  404  may include the same configuration information as the data frame  402 , to confirm that STA 2  received the configuration information correctly. The acknowledgement frame  404  may be configured to accommodate the configuration of the receiver of STA 1 , according to the previously negotiated configuration. For example, as illustrated in the example of  FIG.  4 A , the acknowledgement frame  404  may have a channel width not greater than 80 MHz and may have a number of spatial streams not greater than 3. 
     In response to receiving the acknowledgement frame  404 , STA 1  may configure its receiver according to the configuration specified by the configuration information included in the data frame  402 . As illustrated in the example of  FIG.  4 A , STA 1  configures its receiver to receive signals having a channel width not greater than 40 MHz and having a number of spatial streams not greater than 2. 
     This configuration allows less communication traffic to be received in a fixed amount of time than the previous configuration. This transition may be performed, e.g., if STA 1  has information suggesting that RX traffic will be light, or if STA 1  has a need to conserve power. Thus, STA 1  may use information of which it is aware to efficiently configure its receiver in a configuration that may conserve power while still accommodating RX traffic. 
     While the receiver of STA 1  is configured according to the configuration specified by the configuration information included in the data frame  402 , STA 2  may transmit to STA 1  a data frame  406 . The data frame  406  may be configured to accommodate the configuration of the receiver of STA 1 , as indicated by the configuration information included in the data frame  402 . Specifically, the data frame  406  may have a channel width not greater than 40 MHz and may have a number of spatial streams not greater than 2. For example, the data frame  406  may have 2 spatial streams and a channel width of 40 MHz. As another example, the data frame  406  may have 1 spatial stream and a channel width of 20 MHz. More generally, any frames transmitted by STA 2  to STA 1  subsequent to the acknowledgement frame  404  may accommodate the configuration specified by the configuration information included in the data frame  402 , until STA 1  and STA 2  negotiate a new configuration of the receiver of STA 1 . 
     The data frame  406  may include configuration information specifying a configuration according to which STA 2  intends to configure its receiver. For example, the configuration information may have the same form as the configuration information included in the data frame  402 . The configuration information included in the data frame  406  may be the same as or different than the configuration information included in the data frame  402 . For example, STA 2  may intend to configure its receiver according to a different configuration than the receiver of STA 1 . For example, STA 2  may expect to receive more communication from STA 1  than it expects to transmit to STA 1 . As a specific example, STA 2  may be receiving a video stream from STA 1 , and may therefore desire a channel width greater than 40 MHZ and/or a number of spatial streams greater than 2. 
     As illustrated in the example of  FIG.  4 A , the data frame  406  includes configuration information including an indication of a channel width of 160 MHz and an indication of a number of spatial streams of 8. 
     In response to receiving the data frame  406 , STA 1  may transition to the TX state and transmit an acknowledgement frame  408 . The acknowledgement frame  408  may confirm receipt by STA 1  of the configuration information included in the data frame  406 . For example, the acknowledgement frame  408  may include the same configuration information as the data frame  406 , to confirm that STA 1  received the configuration information correctly. The acknowledgement frame  408  may be configured to accommodate the configuration of the receiver of STA 2 , according to a previously negotiated configuration. 
     In response to receiving the acknowledgement frame  408 , STA 2  may configure its receiver according to the configuration specified by the configuration information included in the data frame  406 . As illustrated in the example of  FIG.  4 A , STA 2  configures its receiver to receive signals having a channel width not greater than 160 MHz and having a number of spatial streams not greater than 8. Any frames transmitted by STA 1  to STA 2  subsequent to the acknowledgement frame  408  may accommodate the configuration specified by the configuration information included in the data frame  406 , until STA 1  and STA 2  negotiate a new configuration of the receiver of STA 2 . 
       FIG.  4 B  illustrates a timeline demonstrating use by a wireless device (STA 2 ) of configuration information for signaling a configuration of a receiver of a remote wireless device (STA 1 ), according to some scenarios. As shown in  FIG.  4 B , STA 1  may transmit to STA 2  a data frame  412 , while in a TX mode. The data frame  412  may include configuration information specifying a configuration according to which STA 1  intends to configure its receiver. The data frame  412  may be similar to the data frame  402 , as discussed above, and may include similar configuration information. As illustrated in the example of  FIG.  4 B , the data frame  412  includes configuration information including an indication of a channel width of 20 MHz and an indication of a number of spatial streams of 1. 
     After transmitting the data frame  412 , STA 1  may transition to an RX state. However, STA 1  may defer configuration of its receiver according to the transmitted configuration information until after it receives a confirmation that STA 2  has received the configuration information. Therefore, when STA 1  enters the RX state, its receiver may be configured according to a previously negotiated configuration. As illustrated in the example of  FIG.  4 B , the receiver of STA 1  is configured to receive signals having a channel width not greater than 40 MHz and having a number of spatial streams not greater than 2. 
     In response to receiving the data frame  412 , STA 2  may transmit an acknowledgement frame  414 , which may confirm receipt by STA 2  of the configuration information included in the data frame  412 . The acknowledgement frame  414  may be similar to the acknowledgement frame  404 , as discussed above, and may include a similar confirmation of configuration information. The acknowledgement frame  414  may be configured to accommodate the configuration of the receiver of STA 1 , according to the previously negotiated configuration. Specifically, the acknowledgement frame  414  may have a channel width not greater than 40 MHz and may have a number of spatial streams not greater than 2. 
     In response to receiving the acknowledgement frame  414 , STA 1  may configure its receiver according to the configuration specified by the configuration information included in the data frame  412 . As illustrated in the example of  FIG.  4 B , STA 1  configures its receiver to receive signals having a channel width not greater than 20 MHz and having a number of spatial streams not greater than 1. 
     While the receiver of STA 1  is configured according to the configuration specified by the configuration information included in the data frame  412 , STA 2  may transmit to STA 1  a data frame  416 . The data frame  416  may be configured to accommodate the configuration of the receiver of STA 1 , as indicated by the configuration information included in the data frame  412 . Specifically, the data frame  416  may have a channel width not greater than 20 MHz and may have a number of spatial streams not greater than 1. More generally, any frames transmitted by STA 2  to STA 1  subsequent to the acknowledgement frame  414  may accommodate the configuration specified by the configuration information included in the data frame  412 , until STA 1  and STA 2  negotiate a new configuration of the receiver of STA 1 . 
     The data frame  416  may include a request for STA 1  to configure its receiver according to a new configuration. The data frame  416  may further include configuration information specifying the new configuration. For example, the configuration information specifying the new configuration may be in place of configuration information specifying a configuration according to which STA 2  intends to configure its receiver, as discussed in connection with the data frame  406  of  FIG.  4 A . Specifically, in some scenarios, the configuration information specifying the new configuration may be in the same or similar form as the configuration information included in the data frame  402 . 
     The request by STA 2  for STA 1  to configure its receiver according to the new configuration may be based, e.g., on information available to STA 2  indicating an expected increase in communication traffic. For example, STA 2  may be aware that it is about to transmit a large amount of communication traffic to STA 1 . In some scenarios, STA 2  may request that STA 1  configure its receiver according to the new configuration in response to determining that the current configuration of the receiver of STA 1  is insufficient to accommodate the volume of communication traffic to be sent by STA 2 . 
     As illustrated in the example of  FIG.  4 B , the data frame  416  includes configuration information including an indication of a channel width of 80 MHz and an indication of a number of spatial streams of 3. 
     In response to receiving the data frame  416 , STA 1  may transition to the TX state and transmit an acknowledgement frame  418 . The acknowledgement frame  418  may confirm the request and/or the configuration information included in the data frame  416 . For example, the acknowledgement frame  418  may include the same configuration information as the data frame  416 , to confirm that STA 1  received the configuration information correctly. Alternatively, the acknowledgement frame  418  may not confirm the configuration information included in the data frame  416 . For example, STA 1  may opt to not configure its receiver according to the new configuration specified by the data frame  416 . In that case, the acknowledgement frame  418  may include other configuration information specifying another configuration according to which STA 1  does intend to configure its receiver. Such other configuration information may specify the current configuration of STA 1 , or may specify a different configuration, such as a compromise configuration having parameters between those of the current configuration and those of the new configuration specified by the data frame  416 . Alternatively, or in addition, the acknowledgement frame  418  may include an indicator of whether the configuration information included in the data frame  416  was accepted or denied, such as an acceptance bit. The acknowledgement frame  418  may be configured to accommodate the configuration of the receiver of STA 2 , according to a previously negotiated configuration. 
     After transmitting the acknowledgement frame  418 , STA 1  may transition to the RX state. In response to receiving the data frame  416 , including the request and the configuration information, STA 1  may configure its receiver according to the new configuration specified by the configuration information. Alternatively, STA 1  may configure its receiver according to the configuration specified in the acknowledgement frame  418 , which may match the new configuration specified by the data frame  416 , or may include another configuration, as described above. As illustrated in the example of  FIG.  4 B , STA 1  configures its receiver to receive signals having a channel width not greater than 80 MHz and having a number of spatial streams not greater than 3, according to the new configuration specified by the data frame  416  and repeated by the acknowledgement frame  418 . 
     While the receiver of STA 1  is configured according to the configuration specified by the configuration information included in the data frame  416  (or in the acknowledgement frame  418 ), STA 2  may transmit to STA 1  a data frame  420 . The data frame  420  may be configured to accommodate the configuration of the receiver of STA 1 , as indicated by the configuration information included in the data frame  416  (or in the acknowledgement frame  418 ). Specifically, the data frame  420  may have a channel width not greater than 80 MHz and may have a number of spatial streams not greater than 3. More generally, any frames transmitted by STA 2  to STA 1  subsequent to the acknowledgement frame  418  may accommodate the configuration specified by the configuration information included in the data frame  416  (or the acknowledgement frame  418 ), until STA 1  and STA 2  negotiate a new configuration of the receiver of STA 1 . 
     The data frame  420  may include configuration information specifying a configuration according to which STA 2  intends to configure its receiver, as discussed in connection with the data frame  406  of  FIG.  4 A . In some scenarios, STA 2  may not intend to change the configuration of its receiver. In such scenarios, the configuration information included in the data frame  420  may specify a configuration identical to the current (e.g. most recently negotiated) configuration of the receiver of STA 2 . As illustrated in the example of  FIG.  4 B , the data frame  420  includes configuration information including an indication of a channel width of 160 MHz and an indication of a number of spatial streams of 8. 
     According to some scenarios, the configuration information discussed in connection with  FIGS.  4 A and  4 B  may be included within a frame header. For example, in the timeline of  FIG.  4 A , the configuration information included in the data frame  406  may be included within a frame header of the data frame  406 . Additionally, the request for a remote wireless device to reconfigure its receiver may also be included within the frame header. For example, in the timeline of  FIG.  4 B , both the request and the configuration information included in the data frame  416  may be included within a frame header of the data frame  416 . 
     As a specific example, the request and configuration information may be included within a MAC header, such as the MAC headers defined by the 802.11 standards. 
     According to some scenarios, the MAC header may include an RX Operating Mode (RXOM) field. For example, the RXOM field may be a 1-byte field. 
     The RXOM field may include an RX Number of Spatial Streams (RXNSS) subfield indicating the maximum number of spatial streams to be received by the receiver. For example, the RXNSS subfield may be a 3-bit subfield indicating values 1-8. 
     The RXOM field may further include an RX Channel Width (RXCW) subfield indicating the channel width of the receiver. For example, the RXCW subfield may be a 3-bit subfield indicating a channel width of 20 MHz, 40 MHz, 80 MHz, or 160 MHz. If implemented as a subfield having 3 or more bits, the RXCW subfield may further be capable of indicating additional channel widths. 
     The RXOM field may further include an RX Mode Request (RXMR) subfield indicating to which receiver the RXOM field is directed. For example, the RXMR subfield may be a 1-bit subfield. In an exemplary scenario, if the RXMR subfield is set to 0, then the RXOM field may be directed to the receiver of the wireless device transmitting the RXOM field. I.e., if the RXMR subfield is set to 0, then the RXNSS subfield and the RXCW subfield may specify a configuration according to which the device transmitting the RXOM field intends to configure its receiver. If the RXMR subfield is set to 1, then the RXOM field may be directed to the receiver of the wireless device to which the frame containing the RXOM field is directed. I.e., if the RXMR subfield is set to 1, then the RXNSS subfield and the RXCW subfield may specify a configuration according to which the device receiving the RXOM field may configure its receiver. Specifically, the RXMR subfield set to 1 may act as a request for the receiving device to configure its receiver according to the configuration specified by the RXNSS subfield and the RXCW subfield. 
     For example, the timelines of  FIGS.  4 A and  4 B  may be implemented using the RXOM field, as follows. 
     In the timeline of  FIG.  4 A , the data frame  402  may include a MAC header including the RXOM field, as defined above. Specifically, the configuration information included in the data frame  402  may include the RXOM field. The RXCW subfield may be set to a value indicating a channel width of 40 MHz. The RXNSS subfield may be set to a value indicating a number of spatial streams of 2. The RXMR subfield may be set to 0, indicating that the RXOM field is directed to the receiver of STA 1 . I.e., the RXMR subfield set to 0 may indicate that the configuration information specifies a configuration according to which STA 1  intends to configure its receiver. The acknowledgement frame  404  may also include a MAC header including the RXOM field, which may be set to the same values as the RXOM field included in the data frame  402 . The data frame  406  may include a MAC header including the RXOM field, in which the RXCW subfield may be set to a value indicating a channel width of 160 MHz, the RXNSS subfield may be set to a value indicating a number of spatial streams of 8, and the RXMR subfield may be set to 0. The acknowledgement frame  408  may also include a MAC header including the RXOM field, which may be set to the same values as the RXOM field included in the data frame  406 . 
     Similarly, in the timeline of  FIG.  4 B , the data frame  412  may include a MAC header including the RXOM field, in which the RXCW subfield may be set to a value indicating a channel width of 20 MHz, the RXNSS subfield may be set to a value indicating a number of spatial streams of 1, and the RXMR subfield may be set to 0. The acknowledgement frame  414  may also include a MAC header including the RXOM field, which may be set to the same values as the RXOM field included in the data frame  412 . The data frame  416  may include a MAC header including the RXOM field, in which the RXCW subfield may be set to a value indicating a channel width of 80 MHz, the RXNSS subfield may be set to a value indicating a number of spatial streams of 3, and the RXMR subfield may be set to 1. Specifically, the RXMR subfield set to 1 may include the request for STA 1  to configure its receiver according to the new configuration. The acknowledgement frame  418  may also include a MAC header including the RXOM field, which may be set to the same values as the RXOM field included in the data frame  412 . Alternatively, the RXMR subfield included in the acknowledgement frame  418  may be set to 0. 
       FIGS.  5 A- 5   —Methods for Receiver-Initiated Receiver Configuration 
       FIGS.  5 A and  5 B  are flowchart diagrams illustrating exemplary methods for reconfiguring a receiver in a wireless device, according to two scenarios. The methods shown in  FIGS.  5 A and  5 B  may be used in conjunction with any of the computer systems or devices shown in the above Figures, among other devices. If desired, it may be the case that each of the methods is more particularly implemented by a wireless device, or, more specifically, by a WLAN/Wi-Fi chipset within a wireless device. Implementing some embodiments of the method of either of  FIGS.  5 A and  5 B  may result in communications according to the timeline of either  FIG.  4 A  or  FIG.  4 B . Some of the method elements shown may be performed concurrently or in a different order than shown, or may be omitted. Additional method elements may also be performed as desired. As shown, the methods may operate as follows. 
     As shown in  FIG.  5 A , at  502 , a wireless device, such as the mobile device  106  or the AP  112 , may transmit a first communication frame. The first communication frame may include first configuration information specifying a first configuration of a receiver in the wireless device. For example, the first configuration information may include at least one of an indication of a channel width of the receiver and an indication of a number of active receive spatial streams of the receiver. The first configuration information may be included in a header of the first communication frame. Specifically, the first configuration information may be included in a MAC header of the first communication frame. 
     According to some embodiments, an RX Operating Mode (RXOM) field, as defined in connection with the description of  FIGS.  4 A and  4 B , may be included in the MAC header of the first communication frame. The RXOM field of the first communication frame may include the first configuration information. The first communication frame may further include an indication that the first configuration information includes a notice from the wireless device that the receiver will be configured according to the first configuration. For example, an RXMR subfield of the RXOM field may constitute the indication that the first configuration information includes a notice from the wireless device that the receiver will be configured according to the first configuration. 
     At  504 , the wireless device may receive a first acknowledgement frame. The first acknowledgement frame may be configured according to a second configuration of the receiver. For example, the second configuration may be a current configuration of the receiver. The first acknowledgement frame may confirm the first configuration information. For example, the first acknowledgement frame may include the first configuration information, e.g., to confirm that it was received properly. The first configuration information may be confirmed in a header of the first acknowledgement frame. Specifically, the first configuration information may be confirmed in a MAC header of the first acknowledgement frame. 
     According to some embodiments, an RXOM field may be included in the MAC header of the first acknowledgement frame. The RXOM field of the first acknowledgement frame may confirm the first configuration information. 
     At  506 , the wireless device may configure the receiver according to the first configuration. For example, the wireless device may configure the receiver to receive signals having a channel width not greater than the channel width indicated by the first configuration information, and having a number of spatial streams not greater than the number of spatial streams indicated by the first configuration information. The configuring the receiver may be in response to the receiving the first acknowledgement frame at  504 . 
     At  508 , the wireless device may receive a second communication frame after the configuring the receiver according to the first configuration at  506 . The second communication frame may therefore be configured according to the first configuration. The second communication frame may include second configuration information specifying a third configuration of the receiver. The second configuration information may be included in a header of the second communication frame. Specifically, the second configuration information may be included in a MAC header of the second communication frame. 
     According to some embodiments, an RXOM field may be included in the MAC header of the second communication frame. The RXOM field of the second communication frame may include the second configuration information. The second communication frame may further include an indication that the second configuration information includes a request from a sender of the second communication frame that the receiver be configured according to the third configuration. For example, an RXMR subfield of the RXOM field may constitute the indication that the second configuration information includes a request from a sender of the second communication frame that the receiver be configured according to the third configuration. 
     At  510 , the wireless device may transmit a second acknowledgement frame. The second acknowledgement frame may confirm the second configuration information. For example, the second acknowledgement frame may include the second configuration information, e.g., to confirm that it was received properly. The second configuration information may be confirmed in a header of the second acknowledgement frame. Specifically, the second configuration information may be confirmed in a MAC header of the second acknowledgement frame. 
     According to some embodiments, an RXOM field may be included in the MAC header of the second acknowledgement frame. The RXOM field of the second acknowledgement frame may confirm the second configuration information. 
     At  512 , the wireless device may configure the receiver according to the third configuration. This may be in response to the receiving the second communication frame at  510 . 
     At  514 , the wireless device may receive a third communication frame after the configuring the receiver according to the third configuration at  512 . The third communication frame may therefore be configured according to the third configuration. 
     As shown in  FIG.  5 B , at  522 , a wireless device, such as the mobile device  106  or the AP  112 , may receive a first communication frame. The first communication frame may include first configuration information specifying a first configuration of a receiver in a remote device. The remote device may also be a wireless device, such as the mobile device  106  or the AP  112 . For example, the first configuration information may include at least one of an indication of a channel width of the receiver and an indication of a number of active receive spatial streams of the receiver. The first configuration information may be included in a header of the first communication frame. Specifically, the first configuration information may be included in a MAC header of the first communication frame. 
     According to some embodiments, an RXOM field, as defined in connection with the description of  FIGS.  4 A and  4 B , may be included in the MAC header of the first communication frame. The RXOM field of the first communication frame may include the first configuration information. The first communication frame may further include an indication that the first configuration information includes a notice from the remote device that the receiver will be configured according to the first configuration. For example, an RXMR subfield of the RXOM field may constitute the indication that the first configuration information includes a notice from the remote device that the receiver will be configured according to the first configuration. 
     At  524 , the wireless device may transmit a first acknowledgement frame. The first acknowledgement frame may be configured according to a second configuration of the receiver. Specifically, the first acknowledgement frame may be configured according to a format that is receivable by the remote device if the receiver of the remote device is configured according to the second configuration. For example, the second configuration may be a current configuration of the receiver. The first acknowledgement frame may confirm the first configuration information. For example, the first acknowledgement frame may include the first configuration information, e.g., to confirm that it was received properly. The first configuration information may be confirmed in a header of the first acknowledgement frame. Specifically, the first configuration information may be confirmed in a MAC header of the first acknowledgement frame. 
     According to some embodiments, an RXOM field may be included in the MAC header of the first acknowledgement frame. The RXOM field of the first acknowledgement frame may confirm the first configuration information. 
     At  528 , the wireless device may transmit a second communication frame. The second communication frame may be configured according to the first configuration. Specifically, the second communication frame may be configured according to a format that is receivable by the remote device if the receiver of the remote device is configured according to the first configuration. The second communication frame may include second configuration information specifying a third configuration of the receiver. The second configuration information may be included in a header of the second communication frame. Specifically, the second configuration information may be included in a MAC header of the second communication frame. 
     According to some embodiments, an RXOM field may be included in the MAC header of the second communication frame. The RXOM field of the second communication frame may include the second configuration information. The second communication frame may further include an indication that the second configuration information includes a request from the wireless device that the receiver be configured according to the third configuration. For example, an RXMR subfield of the RXOM field may constitute the indication that the second configuration information includes a request from the wireless device that the receiver be configured according to the third configuration. 
     At  530 , the wireless device may receive a second acknowledgement frame. The second acknowledgement frame may confirm the second configuration information. For example, the second acknowledgement frame may include the second configuration information, e.g., to confirm that it was received properly. The second configuration information may be confirmed in a header of the second acknowledgement frame. Specifically, the second configuration information may be confirmed in a MAC header of the second acknowledgement frame. 
     According to some embodiments, an RXOM field may be included in the MAC header of the second acknowledgement frame. The RXOM field of the second acknowledgement frame may confirm the second configuration information. 
     At  534 , the wireless device may transmit a third communication frame. The third communication frame may be configured according to the third configuration. Specifically, the third communication frame may be configured according to a format that is receivable by the remote device if the receiver of the remote device is configured according to the third configuration. 
       FIG.  6   —Transmitter-Initiated Receiver Configuration 
       FIG.  6    illustrates a timeline demonstrating use by a wireless device of configuration information for instructing a configuration of a receiver of a remote device, according to some scenarios.  FIG.  6    demonstrates possible behavior of two wireless stations (STA 1  and STA 2 ), as time progresses from left to right. A current state of STA 1  is shown below the timeline. It should be appreciated that the timeline of  FIG.  6    includes only details relevant to the explanation of the present embodiment, and may omit other details. For example, in some scenarios, STA 1  may transition at various times to other states, such as a Listen state, which are not illustrated in  FIG.  6   . 
     Although the two wireless stations are discussed herein as client stations, this is not intended to be limiting, and it should be understood that the illustrated timeline may instead involve communications between other wireless stations, such as between a client station and an AP. For example, the illustrated timeline may be implemented in an identical fashion with an AP in place of STA 1  and/or STA 2 . For example, the illustrated procedures may be implemented by two devices including one or more of the mobile device  106  and the access point  112 . 
     As shown in  FIG.  6   , STA 1  may transmit to STA 2  a mode request frame  602 . The mode request frame  602  may indicate that STA 1  desires to enter a configuration control mode in which STA 2  may define a configuration of a receiver of STA 1 . In some scenarios, the mode request frame  602  may include information regarding the capabilities of the receiver, such as a maximum channel width and/or maximum number of spatial streams that may be supported by the receiver. The mode request frame  602  may further include configuration information regarding an initial or current configuration of the receiver. For example, the configuration information may include an indication of a channel width and/or an indication of a number of spatial streams. In such an example, the configuration information may indicate that the receiver of STA 1  is configured so as to receive signals having a channel width not greater than the indicated channel width and having a number of spatial streams not greater than the indicated number of spatial streams. 
     In response to receiving the mode request frame  602 , STA 2  may transmit a mode response frame  604 . The mode response frame  604  may acknowledge that STA 2  is entering the configuration control mode. The mode response frame  604  may include configuration information regarding an initial configuration of the receiver, e.g. if such information was not provided by STA 1  in the mode request frame  602 . 
     In other scenarios, the mode request frame  602  may be transmitted by STA 2  to STA 1 , and the mode response frame  604  may be transmitted by STA 1  to STA 2 . In either scenario, the timeline may proceed as illustrated following the transmission of the mode response frame  604 . 
     After receiving the mode response frame  604 , STA 1  may transition to an RX state with its receiver configured according to an initial configuration, e.g., as identified in the mode request message  602  or the mode response message  604 . If the mode response message  604  includes configuration information regarding the initial configuration of the receiver, then STA 1  may configure its receiver according to the specified initial configuration. As illustrated in the example of  FIG.  6   , the receiver is initially configured to receive signals having a channel width not greater than 20 MHz and having a number of spatial streams not greater than 1. In some scenarios, this configuration may represent a configuration of minimum power consumption. 
     While STA 1  is configured according to the initial configuration, STA 2  may transmit an aggregated Physical Layer Convergence Protocol (PLCP) protocol data unit (PPDU). The aggregated PPDU (A-PPDU) may include a plurality of back-to-back physical layer (PHY) packets. Specifically, the A-PPDU may include a plurality of back-to-back PPDU packets, such as PPDU 1  and PPDU 2 , as illustrated. Each PPDU packet may include a PLCP Service Data Unit (PSDU) and a PHY header. For example, PPDU 1  is illustrated as including a PHY header  606  and a PSDU  608 . Similarly, PPDU 2  is illustrated as including a PHY header  610  and a PDSU  612 . 
     PPDU 1  may be configured to accommodate the configuration of the receiver of STA 1  according to the initial configuration. Specifically, according to the example of  FIG.  6   , PPDU 1  may have a channel width not greater than 20 MHz and may have no more than 1 spatial stream. 
     However, STA 2  may prefer that the receiver of STA 1  be configured according to a different configuration. For example, STA 2  may prefer that the receiver of STA 1  be configured to accommodate a greater channel width and/or a larger number of spatial streams, e.g., if STA 2  has a large volume of data to transmit to STA 1 . Thus, there may be a discrepancy between the current configuration of the receiver of STA 1  and a different configuration preferred by STA 2 . 
     To resolve this discrepancy, the PHY header  606  of PPDU 1  may include configuration information specifying the different configuration. For example, while STA 1  and STA 2  are in the configuration control mode, the configuration information included in the PHY header  606  may constitute an instruction to STA 1  to configure its receiver according to the different configuration. 
     As illustrated in the example of  FIG.  6   , the PHY header  606  includes configuration information including an indication of a channel width of 80 MHz and an indication of a number of spatial streams of 3. 
     In response to receiving the PHY header  606 , STA 1  may configure its receiver according to the different configuration. As illustrated in the example of  FIG.  6   , the receiver of STA 1  is configured to receive signals having a channel width not greater than 80 MHz and having a number of spatial streams not greater than 3. 
     However, STA 1  may not have sufficient time to configure its receiver before receiving the PSDU  608  of PPDU 1 . Therefore, all of PPDU 1  may be configured to accommodate the configuration of the receiver of STA 1  according to the initial configuration (e.g., having only 1 spatial stream and a channel width not greater than 20 MHz). Thus STA 1  may have until the beginning of PPDU 2  to configure its receiver according to the different configuration specified by the PHY header  606 . 
     PPDU 2  may be configured to accommodate the configuration of the receiver of STA 1  according to the different configuration specified by the PHY header  606 . Specifically, according to the example of  FIG.  6   , PPDU 2  may have a channel width not greater than 80 MHz and may have no more than 3 spatial streams. Any subsequent PPDUs (not shown) included in the A-PPDU may similarly be configured to accommodate this configuration of the receiver of STA 1 . Alternatively, the PHY header  610  or a subsequent PHY header (not shown) may include new configuration information specifying a new configuration of the receiver of STA 1 . In response to receiving the new configuration information, STA 1  may configure its receiver according to the new configuration. 
     In response to receiving the A-PPDU, STA 1  may transmit an acknowledgement frame, such as a block acknowledge (BA) frame  614 . The BA frame  614  may in some scenarios include an indication of whether the configuration information included in the PHY header  606  was accepted or denied, such as an acceptance bit. In other scenarios, the transmission of the BA frame  614  may inherently indicate that the configuration information was accepted. Following transmission of the BA frame  614 , STA 1  may configure its receiver to resume the initial configuration. In scenarios where the initial configuration represents a configuration of minimum power consumption, resuming the initial configuration may serve to conserve power while the receiver is not actively receiving an A-PPDU. The BA frame  614  may include configuration information specifying the initial configuration, to notify STA 2  that STA 1  intends to configure its receiver according to the initial configuration. For example, the configuration information included in the BA frame  614  may be included in a PHY header of the BA frame  614 . 
     According to some scenarios, the configuration information included in the PHY header  606  or other PHY headers may include an RXNSS subfield and an RXCW subfield, similar to those discussed above in connection with  FIGS.  4 A and  4 B . For example, the RXNSS subfield may indicate the maximum number of spatial streams to be received by the receiver. For example, the RXNSS subfield may be a 3-bit subfield indicating values 1-8. The RXCW subfield may indicate the channel width of the receiver. For example, the RXCW subfield may be a 3-bit subfield indicating a channel width of 20 MHz, 40 MHz, 80 MHz, or 160 MHz. If implemented as a subfield having 3 or more bits, the RXCW subfield may further be capable of indicating additional channel widths. 
     It should be appreciated that, although the RXNSS and RXCW subfields included in the PHY header  606  may be structurally and/or functionally similar to the subfields discussed in connection with  FIGS.  4 A and  4 B , they may be distinct subfields. For example, the RXNSS and RXCW subfields discussed in connection with  FIG.  6    may be located in a PHY header, while the RXNSS and RXCW subfields discussed in connection with  FIGS.  4 A and  4 B  may be located in a MAC header, as discussed above. 
     Additionally, it should be appreciated that portions of the methods illustrated and discussed in connection with  FIGS.  4 A and  4 B  may be used in conjunction with the method illustrated and discussed in connection with  FIG.  6   . For example, in the example of  FIG.  6   , a MAC header included in the PSDU  608  may include configuration information specifying a configuration according to which STA 2  intends to configure its receiver, in a manner similar to that described in connection with the data frame  406  of  FIG.  4 A . In such a scenario, STA 1  may confirm the configuration information included in the PSDU  608 , e.g., by including the configuration information in the BA  614 , in a manner similar to that described in connection with the acknowledgement frame  408  of  FIG.  4 A . 
       FIG.  7   —Method for Transmitter-Initiated Receiver Configuration 
       FIG.  7    is a flowchart diagram illustrating an exemplary method for reconfiguring a receiver in a wireless device, according to some scenarios. The method shown in  FIG.  7    may be used in conjunction with any of the computer systems or devices shown in the above Figures, among other devices. If desired, it may be the case that the method is more particularly implemented by a wireless device, or, more specifically, by a WLAN/Wi-Fi chipset within a wireless device. Implementing some embodiments of the method of  FIG.  7    may result in communications according to the timeline of  FIG.  6   . Some of the method elements shown may be performed concurrently or in a different order than shown, or may be omitted. Additional method elements may also be performed as desired. As shown, the method may operate as follows. 
     At  702 , a wireless device, such as the mobile device  106  or the AP  112 , may transmit a mode request frame. The mode request frame may include a request to initiate a configuration control mode. For example, the configuration control mode may allow a remote device (e.g., a remote wireless device, such as the mobile device  106  or the AP  112 ) to command the wireless device to configure a receiver of the wireless device according to a specified configuration. 
     At  704 , the wireless device may receive a mode response frame. The mode response frame may confirm initiation of the configuration control mode. For example, the mode response frame may confirm that the remote device has entered the configuration control mode. 
     At  706 , the wireless device may receive a first communication frame of a plurality of aggregated communication frames. The first communication frame may be configured according to a first configuration of the receiver. For example, the first configuration may be a current configuration of the receiver. The first communication frame may include first configuration information specifying a second configuration of the receiver. For example, the first configuration information may include at least one of an indication of a channel width of the receiver and an indication of a number of active receive spatial streams of the receiver. The first configuration information may be included in a header of the first communication frame. Specifically, the first configuration information may be included in a PHY header of the first communication frame. According to some embodiments, the first configuration information may include an RXCW subfield and an RXNSS subfield, as defined in connection with the description of  FIG.  6   . 
     At  708 , the wireless device may configure the receiver according to the second configuration. For example, the wireless device may configure the receiver to receive signals having a channel width not greater than the channel width indicated by the first configuration information, and having a number of spatial streams not greater than the number of spatial streams indicated by the first configuration information. The configuring the receiver may be in response to the receiving the first communication frame at  706 . 
     At  710 , the wireless receiver may receive a second communication frame of the plurality of aggregated communication frames after the configuring the receiver according to the first configuration at  708 . The second communication frame may therefore be configured according to the second configuration. 
     At  712 , the wireless device may transmit an acknowledgement frame. The acknowledgement frame may include a block acknowledge (BA) frame. For example, the second acknowledgement frame may acknowledge receipt of the plurality of aggregated communication frames. 
     Example Embodiments 
     Some specific examples of the methods disclosed herein may be implemented as follows. 
     A method for reconfiguring a receiver in a wireless device may include the wireless device: receiving a data frame according to a first configuration of the receiver, the data frame having a first header including configuration information specifying a second configuration of the receiver; transmitting an acknowledgement of the data frame, the acknowledgement having a second header confirming the configuration information; reconfiguring the receiver according to the second configuration in response to the receiving the data frame; and receiving a subsequent data frame, after the reconfiguring, according to the second configuration. The configuration information may include at least one of an indication of a channel width of the receiver and an indication of a number of active receive spatial streams of the receiver. 
     A method of managing a wireless communication mode of a wireless device may include the wireless device: receiving a first data frame from a remote device, the first data frame including first configuration information specifying a first configuration of a receiver of the remote device; transmitting to the remote device a first acknowledgement frame according to a format that is receivable by the remote device if the receiver is configured according to a second configuration, wherein the first acknowledgement frame includes a confirmation of the first configuration information; and transmitting to the remote device a second data frame according to a format that is receivable by the remote device if the receiver is configured according to the first configuration, wherein the transmitting the second data frame occurs after the transmitting the first acknowledgement frame. The wireless device may be a mobile device. Alternatively, the wireless device may be an access point. 
     The first configuration information may include at least one of an indication of a channel width of the receiver and an indication of a number of active receive spatial streams of the receiver. 
     The first configuration information may be included in a header of the first data frame, and the confirmation of the first configuration information may be included in a header of the first acknowledgement frame. The header of the first data frame and the header of the first acknowledgement frame may include media access control (MAC) headers. 
     The second data frame may include second configuration information specifying a third configuration of the receiver. The method may then further include the wireless device: receiving a second acknowledgement frame confirming the second configuration information; and transmitting to the remote device a third data frame according to a format that is receivable by the remote device if the receiver is configured according to the third configuration, wherein the transmitting the third data frame occurs after the receiving the second acknowledgement frame. Each of the first configuration information and the second configuration information may include at least one of an indication of a channel width of the receiver and an indication of a number of active receive spatial streams of the receiver. The first data frame may further include an indication that the first configuration information includes a notice from the remote device that the receiver will be configured according to the first configuration; and the second data frame may further include an indication that the second configuration information includes a request from the wireless device that the receiver be configured according to the third configuration. 
     A method for reconfiguring a receiver in a wireless device may include the wireless device: receiving, according to a first configuration of the receiver, a first data frame of a plurality of aggregated data frames, the first data frame including first configuration information specifying a second configuration of the receiver; configuring the receiver according to the second configuration in response to the receiving the first data frame; and receiving, according to the second configuration of the receiver, a second data frame of the plurality of aggregated data frames. The first configuration information may include at least one of an indication of a channel width of the receiver and an indication of a number of active receive spatial streams of the receiver. 
     Embodiments of the present disclosure may be realized in any of various forms. For example some embodiments may be realized as a computer-implemented method, a computer-readable memory medium, or a computer system. Other embodiments may be realized using one or more custom-designed hardware devices such as ASICs. Other embodiments may be realized using one or more programmable hardware elements such as FPGAs. 
     In some embodiments, a non-transitory computer-readable memory medium may be configured so that it stores program instructions and/or data, where the program instructions, if executed by a computer system, cause the computer system to perform a method, e.g., any of a method embodiments described herein, or, any combination of the method embodiments described herein, or, any subset of any of the method embodiments described herein, or, any combination of such subsets. 
     In some embodiments, a wireless device may be configured to include a processor (or a set of processors) and a memory medium, where the memory medium stores program instructions, where the processor is configured to read and execute the program instructions from the memory medium, where the program instructions are executable to implement any of the various method embodiments described herein (or, any combination of the method embodiments described herein, or, any subset of any of the method embodiments described herein, or, any combination of such subsets). The device may be realized in any of various forms. 
     Although the embodiments above have been described in considerable detail, numerous variations and modifications will become apparent to those skilled in the art once the above disclosure is fully appreciated. It is intended that the following claims be interpreted to embrace all such variations and modifications.

Metadata:
Filing Date: 20220107
Publication Date: 20240116
Grant Date: 20240116
Priority Date: 20140711
Inventors: WONG, CHIU NGOK E.
HARTMAN, CHRISTIAAN A.
ZENG, ZHENG
KIM, JOONSUK
YONG, SU KHIONG
LIU, YONG
Assignee: APPLE INC
CPC Classifications: [{"code": "H04W8/183", "inventive": true, "first": true, "tree": "[]"}, {"code": "H04L69/22", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04W52/0216", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04W84/12", "inventive": true, "first": false, "tree": "[]"}, {"code": "Y02D30/70", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04W52/0235", "inventive": true, "first": true, "tree": "[]"}, {"code": "H04W52/0216", "inventive": true, "first": true, "tree": "[]"}, {"code": "H04W8/183", "inventive": true, "first": true, "tree": "[]"}, {"code": "Y02D30/70", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04W52/0216", "inventive": true, "first": false, "tree": "[]"}, {"code": "Y02D30/70", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04L69/22", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04W84/12", "inventive": true, "first": false, "tree": "[]"}]
Family ID: 53610776