Patent Publication Number: US-11659559-B2

Title: Antenna beam switching in multi-access point coordination

Description:
RELATED APPLICATION 
     This application is continuation of U.S. patent application Ser. No. 17/145,226, filed Jan. 8, 2021, the disclosure of which is incorporated herein by reference in its entirety. 
    
    
     TECHNICAL FIELD 
     The present disclosure relates generally to wireless networks. 
     BACKGROUND 
     In computer networking, a wireless Access Point (AP) is a networking hardware device that allows a Wi-Fi compatible client device to connect to a wired network and to other client devices. The AP usually connects to a router (directly or indirectly via a wired network) as a standalone device, but the AP can also be an integral component of the router itself. Several nodes may also work in coordination, either through direct wired or wireless connections in a Wireless Local Area Network (WLAN). The APs, in some WLAN implementations, may work in concert in a scheme called Multi-AP Coordination. Two or more APs can coordinate some operations. However, doing joint uplink transmissions can sometimes, at least, cause interference at the APs. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
       The accompanying drawings, which are incorporated in and constitute a part of this disclosure, illustrate various example(s) of the present disclosure. In the drawings: 
         FIG.  1    is a block diagram of wireless network environment in accordance with aspects of the present disclosure; 
         FIG.  2    is a signaling diagram or signpost diagram of signaling in the wireless network environment in accordance with aspects of the present disclosure; 
         FIG.  3 A  is a block diagram of a wireless device antenna array system in accordance with aspects of the present disclosure; 
         FIG.  3 B  is another block diagram of a wireless device antenna array system in accordance with aspects of the present disclosure; 
         FIG.  3 C  is a block diagram of an AP or other network node device in accordance with aspects of the present disclosure; 
         FIG.  4    is a flow chart of a method for determining a beamwidth for transmission of data to an AP in accordance with aspects of the present disclosure; 
         FIG.  5    is another flow chart of a method for determining a beamwidth for transmission of data to an AP in accordance with aspects of the present disclosure; 
         FIG.  6 A  is a block diagram of a computing device in accordance with aspects of the present disclosure; and 
         FIG.  6 B  is a block diagram of an AP or other networking device in accordance with aspects of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     Overview 
     Optimal determination of wireless network pathway configurations may be provided. A computing device may establish Multi-Access Point (AP) coordination between at least a first AP and a second AP. The first AP can determine an uplink operation is scheduled. When an uplink is scheduled, the first AP can switch its antenna to a narrow beamwidth. The first AP can then receive uplink transmissions from at least a client in the coverage area of the narrow beamwidth. After the uplink transmission, the first AP can then switch the antenna to a larger beamwidth for a next Multi-AP coordination operation. 
     Both the foregoing overview and the following description are examples and explanatory only, and should not be considered to restrict the disclosure&#39;s scope, as described and claimed. Furthermore, features and/or variations may be provided in addition to those described. For example, example of the disclosure may be directed to various feature combinations and sub-combinations described in the example. 
     EXAMPLE 
     The following detailed description refers to the accompanying drawings. Wherever possible, the same reference numbers are used in the drawings and the following description to refer to the same or similar elements. While example(s) of the disclosure may be described, modifications, adaptations, and other implementations are possible. For example, substitutions, additions, or modifications may be made to the elements illustrated in the drawings, and the methods described herein may be modified by substituting, reordering, or adding stages to the disclosed methods. Accordingly, the following detailed description does not limit the disclosure. Instead, the proper scope of the disclosure is defined by the appended claims. 
     WiFi standards, e.g., 802.11ax/be, can support Orthogonal Frequency-Division Multiple Access (OFDMA) downlink, triggered-based OFDMA uplink, and spatial reuse to allow for some co-channel interference. However, it can be useful to reduce co-channel interference during these uplink/downlink events to improve AP performance. New WiFi standards may allow two or more APs to form a multi-AP system, which can have a distributed or centralized coordination. The changes to the standard(s) can allow omnidirectional antennas to perform better in cooperative scenarios when multiple neighboring APs are serving clients in the same channel. The cooperation may help support features such as roaming. The collaboration can also include partial nulling to devices in another AP&#39;s cell. This nulling may require sounding to that device(s), which can result in more overhead and may not be available at each AP. 
     Trigger-based multi-user uplink has not been designed for multi-AP coordination, and trigger-based multi-user uplink may not work properly in at least some coordinated scenarios. Each AP may prefer to schedule clients, in the physical vicinity of the AP, to be able to control better the time of transmissions and the power alignment of transmissions. In this uplink case, for transmitting trigger-frames concurrently at multiple APs, null steering may be required to minimize the downlink interference among the scheduled clients of the multiple APs. Unfortunately, null steering can require soundings to identify the channel of undesired clients to send null signals to those undesired clients. 
     Uplink (UL) Multi-User (MU) (UL MU) can use both OFDMA and MU Multiple Input Multiple Output (MIMO) (MU-MIMO) to facilitate UL MU. Both OFDMA and MU-MIMO can help provide interference-free concurrent transmissions, in a synchronous network, via frequency-division and spatial-division channel sharing among clients. This UL MU method has been introduced in 802.11ax and includes sending downlink trigger frame(s) to align the uplink concurrent transmission from the client stations. A possible requirement of High Efficiency Trigger-Based (HE-TB) UL may be the synchronization of transmissions between the Wi-Fi stations (STAs) and the AP, in terms of timing, frequency, and power. For timing, 802.11ax mandates that STAs transmit within 400 ns of each other. 
     First, in the Downlink (DL) direction, the AP can transmit a trigger frame providing synchronization to the STAs. This trigger frame may also contain information about the OFDMA sub-carriers Resource Unit (RU) assigned to each STA. With the uplink, the participating STAs need to start transmission of the uplink signal after a specified time interval Short Interframe Space (SIFS) of 16 μs+−400 ns, after the end of the trigger frame. The timing requirement in 802.11ax specifies that a STA who participates in UL MU shall ensure the arrival time of a transmitted frame to the AP to be within 0.4 μs of the SIFS+Round Trip Delay (RTD) from the end of Trigger frame transmission. The RTD may be the amount of time it takes for a signal to be sent plus the amount of time it takes for an acknowledgement of that signal to be received. The standard also notes that STAs are not expected to measure or compensate for their RTDs. Hence, for standard-compliant devices, concurrent UL MU frames can arrive at the AP with timing deviation of up to 0.8 μs+maximum RTD according to the environment. The maximum RTD can be the amount of allowed time to receive and respond to a message and not cause issues at the AP. 
     The time alignment is critical for correct decoding of concurrent Physical-layer Protocol Data Unit(s) (PPDU) at the AP. If the inter-PPDU maximum delay reaches the cyclic prefix size, the Inter-Symbols Interference (ISI) will be dominant, which can result in data loss. 
     A set of APs can form a multi-AP system. There can be at least two types of multi-AP systems: a coordinated system and a joint system. The coordinated systems can send and/or receive each portion of data by a single AP. The joint system can send and/or receive data by multiple APs. Some of the coordination possible in the multi-AP systems can include Coordinated OFDMA (Co-OFDMA), null steering, and/or joint transmission and reception. 
     Most of the above techniques, e.g. null steering, can require the channel state information of clients (e.g., desired/intended and undesired clients) be sent to all APs, which has made the sounding procedure very challenging. Thus, there is a need to find other procedures to enable the Multi-AP efforts. Enabling coordinated uplink transmissions is particularly important to prevent interference that could occur and affect service quality. 
     In the multi-AP coordination, the coverage area (e.g., the cell size) of each AP is large to effectively leverage the advantages of coordination. However, the current design of coordinated APs does not provide the benefit for the TB-UL scheme because of several reasons. The Media Access Control (MAC) scheduler&#39;s preference is to select STAs physically near to the AP to keep the ISI at minimum because of round-trip delay issue. Also, the Trigger frame may take the channel of the entire group of joint APs while the intention is to only trigger the STAs nearby. Further, sounding may be required for finding the channels to desired clients and clients that may need null signals. Therefore, there is a need to keep the functionality of the TB-UL while keeping the advantage of multi-AP coordination. 
     The aspects herein can provide for an antenna beam switching mechanism to better support Extremely High Throughput (EHT) TB-UL while providing efficient multi-AP coordination. Using a switchable antenna, a dual mode of an antenna beam can be used for normal coordinated Multi-AP phases and EHT TB UL. These two antenna modes can include a wide beam and a narrow(er) beam. The wider antenna beam can be used for the normal operation of multi-AP operations. In contrast, for the EHT TB UL, the narrow(er) beamwidth may be employed. 
     In at least some implementations, a centralized scheduler (e.g., a master AP) can coordinate the uplink transmission. During the normal mode of operation, the antenna beamwidth is wide (e.g., in an omni-directional configuration) to support multi-AP coordination capabilities, as discussed above. When uplink traffic is scheduled in all or some of the APs in the coordinated AP set, APs can switch to the micro configuration (e.g., switch to a smaller beamwidth). 
     Stations can be organized into groupings for the uplink transmissions. The uplink grouping may be weighted towards RU allocation that includes devices in the macro-cell. This arrangement can be the default to avoid large delay spreads in the window of the received trigger-based UL(s) across all the devices. During uplink scenarios, the trigger frames can be sent to the desired clients inside the micro coverage area. If joint Physical layer (PHY) reception is not enabled, the antenna mode may be the same for uplink frames too. In this scenario, the inter-AP interference can be reduced. With this solution, the multi-AP coordination can be used with lower overhead for the purpose of uplink multiuser transmissions. In an example, uplink frames can be sent with no joint reception. The antenna configuration is unchanged for the entire EHT TB UL sequence. 
     The aspects herein can include grouping of clients. For uplink multi-user transmissions, the AP can have a group of clients, in closer physical proximity, to minimize the effect of round trip delay between nearest and furthest clients. Therefore, the uplink grouping is weighted towards RU allocation that includes devices in the macro-cell. Scheduling of clients can better support the method as follows. First, the Received Signal Strength Indicator (RSSI) of clients in normal/macro operation can be collected. Then, the RSSI of received uplink packets can be collected in the micro/narrow beam configuration, which can be done by transmitting trigger frame(s) to single client(s). Then, the AP can compare the RSSIs to determine the possibility of scheduling the client with the proposed UL method. For example, if the maximum difference, in RSSIs, is larger than a predefined maximum number, the client cannot be part of the proposed uplink. Further, if the client is on the edge of macro coverage area, then there is a high probability that that client will not receive the trigger frame in micro mode, and the client should not be added to the UL group. 
     As mentioned, the beamwidth/directivity of some antennae is controllable. Therefore, the AP can determine a best beamwidth for these controllable antennae. The antenna beamwidth can be selected based on one or more criteria, which can include, but is not limited to, the maximum tolerable RTD, and/or the overlap between two micro areas from two APs. The aspects herein can include a calibration mechanism for the APs to satisfy these criteria. 
     The calibration method can include a calculation of the maximum beamwidth that covers only the radius less than the max RTD. Then, the AP can set the beamwidth of the AP to the calculated RTD maximum value from 1. The AP may then transmit trigger frame(s) to only one AP. For the two or more clients that have been selected for the uplink group of the AP, it does not matter if this trigger is being sent by a narrow or a wider beam. Then, the coordinated APs can set the antenna of other APs (in coordination) in the narrow/micro beam. If the uplink packets are received at any other AP in the coordinated group, the AP(s) can reduce the beamwidth of the antenna and repeat the procedure above. Otherwise, if no uplink packet is received after the trigger event, the coordinated AP(s) can repeat the process for the other APs. 
     It should be noted that this calibration does not need to be done frequently, and the intervals are not similar to Channel State Information (CSI)/sounding. Thus, the aspects herein provide a system that is drastically more stable than MU-MIMO-type transmissions. 
     A wireless environment  100  may be as shown in  FIG.  1   . The wireless environment  100  can include a wireless local area network (WLAN), which may be referred to as WLAN  100 , which can include two or more nodes, e.g., APs  102   a  and  102   b . The wireless environment  100  shows just two APs  102 , but the wireless environment  100  can include two or more APs  102 . APs  102  can function in a multi-AP coordination environment. Therefore, the APs  102  can communicate with each other to conduct operations in concert. 
     The APs  102  may be in communication with one or more client stations  108   a - 108   g , which may also be referred to simply as clients  108  or simply as stations  108 . The stations  108  may be physically dispersed through a physical area covered by APs  102  of the WLAN  100 . The stations  108  and the APs  102  may be wireless devices, as described in conjunction with  FIG.  6 B  and may be computing systems, as described in conjunction with  FIG.  6 A . The network  100  can be controlled by a controller (not shown), e.g., a WLC, a network controller, etc. The controller may be a computer system, wireless device, and/or another device, as described in conjunction with  FIGS.  6 A and  6 B . 
     As stated above and as shown in  FIG.  1 A , the wireless network  100  may comprise Wi-Fi APs  102  (e.g., first AP  102   a  and/or second AP  102   b ) that may be configured to support a wireless (e.g., Wi-Fi) network  100 . The APs  102  may comprise a physical location where a user, operating a client station  108 , may obtain access to a wireless network  100  (e.g., Internet access), using Wi-Fi technology, via a WLAN using a router connected to a service provider. 
     In another example(s) of the disclosure, rather than APs  102 , devices may be used that may be connected to a cellular network that may communicate directly and wirelessly with end use devices (e.g., a client station  108  device) to provide access to wireless network  100  (e.g., Internet access). For example, these devices may comprise, but are not limited to, eNodeBs (eNBs) or gNodeBs (gNBs). The aforementioned cellular network may comprise, but is not limited to, a Long Term Evolution (LTE) broadband cellular network, a Fourth Generation (4G) broadband cellular network, or a Fifth Generation (5G) broadband cellular network, operated by a service provider. Notwithstanding, example of the disclosure may use wireless communication protocols using, for example, Wi-Fi technologies, cellular networks, or any other type of wireless communications. 
     Client station devices  108  may comprise, but are not limited to, a phone, a smartphone, a digital camera, a tablet device, a laptop computer, a personal computer, a mobile device, a sensor, an Internet-of-Things (IoTs) device, a cellular base station, a telephone, a remote control device, a set-top box, a digital video recorder, a cable modem, a network computer, a mainframe, a router, or any other similar microcomputer-based device capable of accessing and using a Wi-Fi network or a cellular network. 
     The elements described above of the wireless network  100  (e.g., WLC, first AP  102   a , second AP  102   b , client devices  108   a - 108   g , etc.) may be practiced in hardware, in software (including firmware, resident software, micro-code, etc.), in a combination of hardware and software, or in any other circuits or systems. The elements of wireless network  100  may be practiced in electrical circuits comprising discrete electronic elements, packaged or integrated electronic chips containing logic gates (e.g., Application Specific Integrated Circuits (ASIC), Field Programmable Gate Arrays (FPGA), System-On-Chip (SOC), etc.), a circuit utilizing a microprocessor, or on a single chip containing electronic elements or microprocessors. Furthermore, the elements of wireless network  100  may also be practiced using other technologies capable of performing logical operations such as, for example, AND, OR, and NOT, including but not limited to, mechanical, optical, fluidic, and quantum technologies. As described in greater detail below with respect to  FIGS.  6 A and  6 B , the elements of wireless network  100  may be practiced in a computing device  600  and/or wireless device  630 . 
     The APs  102  may function with an antenna system, as described in conjunction  FIGS.  3 A and  3 B . The antenna system may be operable to electronically control the beam or the coverage area  106  (also referred to as a micro-cell) of the AP  102 . For example, AP 1   102   a  can have a narrow(er) beam, which covers an area  106   a . Likewise, AP 2   102   b  can have a narrow(er) beam coverage area  106   b . However, both APs  102   a ,  102   b  may have larger widebeam coverage areas  104   a ,  104   b  (also referred to as a macro-cell). The AP(s)  102  can selectively change the coverage area  104 ,  106 , depending on the conditions or the types of operations being conducted by the APs  102 . 
     The area between or covered by both coverage areas  104   a ,  104   b  may be a coverage area for coordinated AP operations. The multi-AP coordination area includes the stations  108   a - 108   g . Thus, various operations may be coordinated between the two APs  102   a ,  102   b  for these several stations  108 . However, in some situations, the APs  102  may only use the narrow beam with coverage area  106 , for example, during uplink of multiple clients  108 . 
     An embodiment of a signaling process  200  may be as shown in  FIG.  2   . Signaling process  200  can include both an uplink operation  202  and a downlink operation  204 . In multi-AP coordination, the uplink data transmission may cause interference between multiple APs  102  if the station is in the coverage area  104  of both APs  102 . Therefore, each AP  102  may use a narrow antenna beam during the uplink process  202 , as shown in  FIG.  2   . Thus, the APs  102  may use the smaller coverage area  106  during uplink operations. 
     During uplink, AP 1   102   a  may send the trigger frame  206   a  to the stations  108   a  through  108   c , within in the narrow beam with coverage area  106   a . Likewise, stations  108   d - 108   e  are in temporal proximity to AP 2   102   b , which can send the trigger frame  206   b  in the narrow coverage area  106   b  to stations  108   d - 108   e . The different stations  108  may receive the trigger frames  206  and send uplink MU MIMO/OFDMA RUs  208   a ,  208   b . The one or more APs  102  may respond to the RUs  208  with the block acknowledgments (BA)  210   a ,  210   b . In this way, the uplink occurs with the narrow beam at the APs  102  which prevents interference at stations  108  close to the other AP  102 . 
     In contrast to the uplink operations  202 , other multi-AP coordination efforts, for example, joint DL transmission of information or other operations, as described herein, may occur with a wide antenna beam, in operations  204 . During operation  204 , the APs  102  may use a wide coverage area  104   a ,  104   b . During this multi-AP coordination operation, the APs  102   a ,  102   b  may send joint transmissions  212   a ,  212   b  to the various stations  108 . The stations  108  can respond with BAs  214 . Thus, unlike uplink transmissions in operation  202 , other multi-AP coordination efforts, in operations  204 , may occur jointly and not cause interference, which may happen during uplink operations. 
     An example AP  102 , with an antenna array, may be as shown in  FIGS.  3 A and  3 B . The AP  102  can include a processing component and a radio component. The radio component  300  can have one or more antennas  304   a - 304   d . Each AP  102  may include more than one radio component(s)  302   a  through  316   b.    
       FIG.  3 A  illustrates an example implementation of a component layout for an example antenna segment  300 , according to example(s) of the present disclosure. Each antenna segment  300  is configured to operate a narrow-beam antenna array  302  and/or a wide-beam antenna array  314  (at a given time). The narrow-beam antenna array  302  provides an N×N array of antenna elements, whereas the wide-beam antenna array  314  provides a 1×M array of antenna elements. It should be noted that, in some configurations, wide-beam antenna array  314  may be a part of the elements forming the narrow-beam antenna array  302 . The number of elements (e.g., the individual signaling elements making up the antenna arrays) in an array determines the beamwidth in azimuth and elevation. The layout of the narrow-beam patch  302  can, in some implementations, provide an (N−2)×(N−2) subset of inner antenna elements  306 , which are surrounded by a subset of outer antenna elements (i.e., those antenna elements included in the narrow-beam antenna array  302  that are not neighbored by at least four antennas). 
     The narrow-beam antenna array  302  and the wide-beam antenna array  314  can be dual polarized antenna arrays. By being dual polarized, two different radio paths can use the same array at the same time. One path is connected to a vertical polarization feed, while the other is connected to a horizontal polarization feed, essentially providing two antenna arrays with one set of elements. 
     Signals are routed to/from the narrow-beam antenna array  302  or the wide-beam antenna array  314  via a switching pathway. The switching pathway includes several switches  310   a - b  and  312   a - b  that route signals to/from the activated antenna array. Base switches  312   a - b  determine whether the signals are routed to/from the narrow-beam array  302  or the wide-beam antenna array  314 , whereas intermediary switches  310   a - b  route the signals to/from the phase shifters  308   a - b  connected to the narrow-beam antenna array  302 . Although illustrated with one arrangement of switching components, it will be appreciated that various other arrangements of switching components (including cascaded 2:1 switches) can be used to link the antenna arrays to various signaling sources. 
     The low side lobes formed through aggressively tapering the narrow beam prevent APs  102  in the same frequencies from detecting one another&#39;s transmissions, even when mounted in close proximity to one another (e.g., within 50 feet). In some implementations, the side lobes have an amplitude of −30 dB relative to the main lobes of the narrow beam. In various examples, unequal power dividers and attenuators are used to provide lower powered signals to the outer antenna elements of the narrow-beam antenna array  302  than the inner antenna elements, thereby reducing the power of the side lobes relative to a main lobe. Due to the control of the side lobe amplitude, the antenna segment  300  (and any antenna array including the antenna segment  300 ) can omit band-pass filters  316   a - b  that are typically used to increase isolation between co-located radios within an AP  102 , although in some examples, the band-pass filters can be retained to increase co-located radio isolation. 
     A pair of phase shifters  308   a - b  is connected to each feed of the dual-polarized narrow-beam antenna array  302 , which allows for each polarization of the beam to be steered. These positions can include a neutral position, where no steering is applied, a positive offset from the neutral position in a first direction, and a negative offset from the neutral position in a second direction opposite to the first direction. In various implementations, the phase shifters  308   a - b  are Butler matrices, but other switched phase feed networks can be used as phase shifters  308   a - b  to steer the beams in discrete increments while maintaining minimal side lobes. The first phase shifter  308   a  steers the first beam for the vertical polarization by phase shifting the first signal across columns of the narrow-beam antenna array  302 , and wherein the second phase shifter  308   b  steers the first beam for the horizontal polarization by phase shifting the second signal across columns of the narrow-beam antenna array  302 . 
     In various examples, the phase shifters  308   a - b  steer the narrow beam by creating relative phase differences in the columns of the narrow-beam array  302 . For example, when steering to a positive offset, if the first column  304   a  has a phase of A, the second column  304   b  would have a phase of A+B where B is a fixed phase difference determined to create the desired degrees of steering. The third column  304   c  would have a phase of A+(2*B), and the fourth column  304   d  would have a phase of A+(3*B). To steer to a negative offset, if the first column  304   a  has a phase of A, the second column  304   b  would have a phase of A−B where B a fixed phase difference determined to create the desired degrees of steering. The third column  304   c  would have a phase of A−(2*B), and the fourth column  304   d  would have a phase of A−(3*B). To remain at the neutral or zero-offset position, the phases across the columns  304   a - d  are all equal. In some implementations, the APs  102  can steer the narrow beams to ensure the coverage areas  106  do not overlap or cause interference at one or more STAs  108 . 
     The wide-beam antenna array  314  produces a fixed position beam (e.g., the beam covering coverage area  104  discussed in  FIG.  1   ), whereas the narrow-beam antenna array  302  produces an electronically steerable beam (e.g., the beam to focus on the coverage area  106  discussed in  FIG.  1   ). The narrow-beam antenna array  302  produces a beam of a first beamwidth, which is less than the beamwidth of the beam produced by the widebeam antenna array  314 . In various examples, the beamwidth of the beam produced by the wide-beam antenna array  314  includes or encompasses all of the coverage ranges of the beam produced by the narrow-beam antenna array  302  steered to any of the potential positions thereof. 
       FIG.  3 B  illustrates a component layout for an antenna array  320 , according to examples of the present disclosure. The antenna array  320  includes four instances of an antenna segment  300   a - d , as described in relation to  FIG.  3 A , and an interface  318  acting as a signal source for signals to transmit via the antenna segments  300   a - d , and may be used as a steerable and switchable antenna array for various APs  102 . In various examples, two or more radios are connected to the antenna segments  300   a - d  (and/or alternative antennas) via the interface  318 . 
     In various examples, additional alternative antennas can also be connected (via one or more switches) to various ports of the interface  318  to allow for different frequencies, communication standards, or beam patterns to be used in the antenna array  320 . For example, the antenna segments  300   a - d  can operate in a first frequency bandwidth (e.g., 5 GHz) from all of the radios sending signals via the ports of the interface  318  (e.g., ports ABCD and EFGH), but additional antennas (not illustrated) connected to a subset of the ports (e.g., ports EGHG) can operate in a second frequency bandwidth (e.g., 2.4 GHz). 
     Using four instances of the antenna array  320 , an AP  102  is configured to operate in a dual 4×4 MIMO mode with no mutual interference between radios. Accordingly, due to the beam shaping and tapering provided by the individual antenna segments  300   a - d  (e.g., precise antenna pattern with low side lobe levels), the antenna array  320  allows for high-channel reuse in high-density applications where several APs  102  are deployed with corresponding instances of the antenna array  320 . Switchable beam directions allow flexibility in aligning cells in the same or adjoining coverage areas  104 / 106  for the different APs  102  so that several APs  102  can be grouped closely together (e.g., within 50 feet of one another). 
     An embodiment of one or more components, associated with the APs  102 , may be as shown in  FIG.  3 C . The APs  102  can include components  321 , which may be part of or executed as part of the computing system  600  as is shown in  FIG.  6 A . These components  321  can include one or more of, but are not limited to, a client monitor  322 , a grouping director  324 , a client beam determiner  326 , an uplink interference monitor  328 , and/or an AP coordinator  330 . 
     The client monitor  322  can monitor the one or more stations  108 . The monitoring can determine the RSSI of the uplink signals from each of the client stations  108 . Further, other measures may be monitored for the stations  108 , including the Quality Of Service (QOS) indicators, data loss, client station location(s), and other metrics and measures of the service being provided to the client stations  108 . This data may then be provided to the other components  324 - 330 . 
     A grouping director  324  may determine which client stations  108  may be part of the group to conduct uplink within the narrow beam coverage area  106 . Thus, the grouping director  324  can determine locations for client stations  108 . Further, the grouping director  324  may decide or indicate whether those stations  108  are capable of providing or conducting uplink transmissions, as provided in  FIG.  2   . Based on the information provided about clients  108  in a group, the grouping director  324  can store data structures, indicating which clients  108  are currently within the narrow beam coverage area  106 , may conduct uplink operations  202 , as shown in  FIG.  2   , and store the data structure in the memory  515  of the AP  102 . 
     The grouping director  324  and client monitor  322  may provide data to the client beam determiner  326 . The client beam determiner  326  can change the coverage area  104 / 106  by manipulating the beamwidth of the antenna, as described in conjunction with  FIGS.  3 A and  3 B . Thus, the coverage area  106 , as is shown in  FIG.  1   , may only be exemplary and may be larger or smaller or may be steered in one or more planes depending on the operation of the antenna and the needs of the uplink operation. The client beam determiner  326  can then modify this size of the coverage area  106  in relation to the client stations  108  and those stations  108  being serviced by the other AP  102   b  that is in multi-AP coordination. Thus, the second AP  102   b  may send information to the first AP  102   a  for the client beam determiner  326  to determine if the coverage area  106   a  is causing interference problems with the second AP  102   b . In other implementations, the stations  108  being serviced by the second AP  102   b , e.g., station  108   d  and station  108   e , may also be sending signals to the AP  102   a  for the client beam determiner  326  to determine if there is any interference. Based on these different measures, the client beam determiner  326  can determine the current coverage area  106   a  and may manipulate that coverage area  106   a  over a period of time. When the environment changes, the client beam determiner  326  can also change the coverage area  106 , based on the current needs of the coverage area  106  and the client stations  108 . 
     The uplink interference monitor  328  can monitor issues with uplink signals from the stations  108 . The interference can manifest as changes in the RSSI, QOS indicators, or other information. Based on this information, the uplink interference monitor  328  may provide that information back to client monitor  322 . The changes to or detection of interference can also be communicated to the AP 2   102   b . Thus, if the two APs  102   a ,  102   b  are in multi-AP coordination, the uplink interference monitor  328  may indicate to the other AP  102   b  that the AP&#39;s operations are causing interference with AP  102   a  uplinks. This information or signal from the uplink interference monitor  328  can trigger changes to operation with a narrow antenna beam operation  202 , or into changes of the coverage areas  106 . 
     The AP coordinator  330  can coordinate with the other APs  102 . For example, the AP coordinator  330 , of the first AP  102   a , can receive information from the second AP  102   b  as to whether there is interference with the other APs&#39; signals. The AP coordinator  330  can conduct the other multiple multi-AP coordination operations, as described previously. Any communication or coordination between APs  102  may be conducted by the AP coordinator  330 . 
     Referring now to method  400  of  FIG.  4   , the method  400  can provide a method for grouping or determining which clients should be provided with what type of service by the AP  102 , in accordance with aspects of the disclosure. The method  400  can start with a start operation and can end with an end operation. The method  400  can include more or fewer steps or can arrange the order of the steps differently than those shown in  FIG.  4   . The method  400  can be executed as a set of computer-executable instructions, executed by a computer system or processing component, and be encoded or stored on a storage medium. Further, the method  400  can be executed by a gate or other hardware device or component in an ASIC, a FPGA, a SOC, or other type of hardware device. Hereinafter, the method  400  shall be explained with reference to the systems, components, modules, software, data structures, etc. described herein. 
     AP  102  can collect the RSSIs of clients  108  in a first macro operation, in stage  402 . The AP  102  can collect RSSI information from one or more stations  108 , in the wide coverage area  104 . The RSSI from the client stations  108  can determine the physical proximity of the stations  108  to the AP  102 . For example, a first station  108   a , with better RSSI and other indicators, may be determined to be closer to the AP  102   a  then STA  6   108   f  that has RSSI information that indicates a further physical separation from the AP  102 . This RSSI may be collected by a client monitor  322  at the AP  102 . 
     The AP  102  may then collect the RSSI for uplink packets for clients  108 , in a micro operation, in stage  404 . The client monitor  322  may collect RSSI, when the AP  102  changes to a narrow beam, to receive uplink transmissions from stations  108 , in coverage area  106 . The client monitor  322  may determine the RSSI for different clients  108  and to determine or better determine which stations  108  are within the coverage area  106  of the narrow beam of the AP  102 . The steps or stages  402 / 404  may be iterative and repeated periodically (e.g., every second, every minute, etc.) as the AP  102  can change from the wide coverage area  104  to the narrow coverage area  106 . The coverage area  106  may expand or contract depending on the information received by the client monitor  322  and reported to the client beam determiner  326 . 
     The AP  102  may then determine if the client  108  is a candidate for the narrow beam uplink, in a micro operation  202 , in stage  406 . The client monitor  322  may provide the information about the RSSI or other measures to the grouping director  324 . The grouping director  324  can select one or more clients  108  that may be candidates for providing uplink data, in the micro operation  202 , in the narrow beam coverage area  106 . In an implementation, the RSSI from the wide beamwidth transmission can be compared to the RSSI from the narrow beamwidth transmission. If the difference between these two RSSIs crosses a predetermined threshold (e.g., less than 20% difference), the client can be determined to be a candidate for the narrow beamwidth operations. 
     There may be a limitation on the number of clients  108  able to or allowed to provide uplink information, in the micro operation  202 . For example, the AP  102  may only be capable of handling or managing four client stations  108  during uplink operations  202 . As such, only four stations  108  may be chosen by the grouping director  324  to service during micro operations  202 . The station information, for example, an identifier for station (e.g., a numeric identifier, an alphanumeric identifier, a Globally Unique Identifier (GUID), a MAC address, a Uniform Resource Locator (URL), etc.), or other types of information may be stored in a data structure to identify the station  108 , as part of the micro operation group. This station information may then be provided to the client beam determiner  326 . 
     The AP  102  can then determine the best beamwidth for the clients  108  to be used in the micro operations  202 , based on one or more predetermined criteria, in stage  408 . The client beam determiner  326  can determine the coverage area  106  of the narrow beam. The narrow beam can change the coverage area  106 . The criteria used to determine the size of the coverage area  106  may include, for example, one or more of, but is not limited to, the RSSI of each station  108 , the position or location of the stations  108 , the location of the other APs  102   b  in the multi-AP coordination group, the location of the stations  108  being serviced by the other AP  102   b , the locations of stations that may be outside the coverage area  106  or not communicated to in the micro operation  202 , the RTDs of the stations  108 , or other types of measures. This information may be used to determine the best beamwidth for using for uplink with the stations  108  without causing interference to other stations  108 . 
     An embodiment of a method  500  for determining the coverage area  106 , of the narrow beam antenna, may be as shown in  FIG.  5    in accordance with aspects of the disclosure. The method  500  can start with a start operation and can end with an end operation. The method  500  can include more or fewer steps or can arrange the order of the steps differently than those shown in  FIG.  5   . The method  500  can be executed as a set of computer-executable instructions, executed by a computer system or processing component, and be encoded or stored on a storage medium. Further, the method  500  can be executed by a gate or other hardware device or component in an ASIC, a FPGA, a SOC, or other type of hardware device. Hereinafter, the method  500  shall be explained with reference to the systems, components, modules, software, data structures, etc. described herein. 
     The AP  102  can calculate the maximum beam, which the covers a radius less than the maximum RTD for one or more APs  102 , in stage  502 . The client monitor  322  can monitor the RSSI and the timing of packets being sent to and/or from the stations  108 . The client monitor  302  can calculate the maximum RTD and other information to determine locations of the stations  108 , from the signal strength. This information may be sent to the client beam determiner  326 . From this information, the client beam determiner  326  can determine the maximum radius of the coverage area  106  that covers the stations  108 , but also is less than what is required for the maximum RTD to allow for proper uplink transmission. 
     The AP  102  can then set the beamwidth of the antenna  300  to the calculated maximum value of one, in stage  504 . The client beam determiner  326  can set the beamwidth to this calculated maximum and then set that value as one. In this way, the client beam determiner  326  can modify the coverage  106  up or down by changing the set value from one. 
     The AP  102  can then transmit the trigger frame  206 , to the client  108  that is selected for uplink, in stage  506 . Here, the trigger frame  206  may be sent by the RF portion of the AP  102 , as described in conjunction with  FIG.  6 B , to the different client stations  108 . The client stations  108  include those clients, e.g., clients  108   a - 108   c , within the coverage area, e.g., coverage area  106   a , that have been selected for uplink. The trigger frame  206  is sent to the one or more stations  108  to determine or receive uplink transmissions, e.g., uplink MU MIMO/OFDMA RUs  208 . The APs  102  may communicate to determine if the other AP  102  or clients serviced by the other AP  102  receives the trigger frame  206  or other data. This information may be sent to the beam determiner  326 . 
     The AP  102  then sets the antenna beamwidth, in coordination with the other APs  102 , in stage  508 . The AP coordinator  330 , of a first AP  102   a , can send signal information, e.g., antenna state, client RSSI information, etc., to the second AP  102   b  to set the antenna for receiving uplink transmissions. Further, the AP coordinator  330 , of the AP  102   a , can also receive similar signal information from the other AP  102   b . In this way, the antenna is set to an antenna beamwidth that covers coverage area  106  that should not interfere with the second AP  102   b . Further, the direction of reception for the antenna or other types of parameters, for example, transmit power, may be also set based on coordination with the other AP  102 , as conducted by the AP coordinator  330 . 
     The AP  102   a  can determine if an uplink packet is received from the other AP  102   b , in stage  510 . The uplink interference monitor  328  can measure or detect packets that may be received from the other AP  102   b . For example, the uplink interference monitor  328  can scan for and/or detect the trigger frame  206  (or other signals or packets) that may be sent from the second AP  102   b  or clients in coverage area  106   b . Other packets that may be sent and detected from the other AP  102   b  can include the BAs  210   b , transmissions  212   b , or other types of packets or signals. If an uplink packet is received from the other AP  102   b , or clients  108   d - 108   e , the method  500  proceeds “YES” to stage  512 . However, if no packet is received from the other AP  102   b , or clients  108   d - 108   e , the method  500  proceeds “NO” to stage  514 . 
     In stage  512 , the AP  102   a  reduces the AP&#39;s beamwidth. The beamwidth can be adjusted by the client beam determiner  326  and the RF component. The new beamwidth information may be presented to the uplink interference monitor  328 , the client monitor  322 , the group director  324 , etc., to repeat the stages  506 - 510  as described above. The interference monitoring and the adjustment of the beamwidth can be repeated to modify (e.g., shrink) the coverage area(s)  106   a / 106   b , as needed. 
     In stage  514 , the AP  102   a  determines if the other AP  102   b  needs to determine a new beamwidth. The interference monitor  328  may send information about interference from AP  102   b  to the AP coordinator  330 . If there is interference from the other AP  102   b , the interference information may be sent to the other AP  102   b  through the AP coordinator  330 . If there is interference and the other AP  102   b  needs to determine its beamwidth, the method proceeds “YES” back to stage  502 . If the other AP  102   b  does not need to re-determine a new beamwidth, the method  500  proceeds “NO” to an end operation. 
       FIG.  6 A  shows computing device  600 . As shown in  FIG.  6 A , computing device  600  may include a processing unit  610  and a memory unit  615 . Memory unit  615  may include a software module  620  and a database  625 . While executing on processing unit  610 , software module  620  may perform, for example, processes for changing the beamwidth for some operation in Multi-AP coordination, as described above with respect to  FIGS.  1 - 5   . Computing device  600 , for example, may provide an operating environment for the controller, the APs  102 , the clients  108 , or the other devices, however, the controller, APs  102 , the clients  108 , and other devices may operate in other environments and are not limited to computing device  600 . 
     Computing device  600  may be implemented using a Wi-Fi access point, a cellular base station, a tablet device, a mobile device, a smart phone, a telephone, a remote control device, a set-top box, a digital video recorder, a cable modem, a personal computer, a network computer, a mainframe, a router, a switch, a server cluster, a smart TV-like device, a network storage device, a network relay devices, or other similar microcomputer-based device. Computing device  600  may comprise any computer operating environment, such as hand-held devices, multiprocessor systems, microprocessor-based or programmable sender electronic devices, minicomputers, mainframe computers, and the like. Computing device  600  may also be practiced in distributed computing environments where tasks are performed by remote processing devices. The aforementioned systems and devices are examples and computing device  600  may comprise other systems or devices. 
       FIG.  6 B  illustrates an embodiment of a communications device  630  that may implement one or more of APs  102 , the clients  108 , controllers, etc., of  FIGS.  1 - 5   . In various embodiments, device  630  may comprise a logic circuit. The logic circuit may include physical circuits to perform operations described for one or more of APs  102 , the clients  108 , controllers, etc., of  FIGS.  1 - 5   , for example. As shown in  FIG.  6 B , device  630  may include one or more of, but is not limited to, a radio interface  635 , baseband circuitry  640 , and/or computing platform  600 . 
     The device  630  may implement some or all of the structures and/or operations for APs  102 , the clients  108 , controllers, etc., of  FIGS.  1 - 5   , storage medium, and logic circuit in a single computing entity, such as entirely within a single device. Alternatively, the device  630  may distribute portions of the structure and/or operations using a distributed system architecture, such as a client station-server architecture, a peer-to-peer architecture, a master-slave architecture, etc. 
     A radio interface  635 , which may also include an analog front end (AFE), may include a component or combination of components adapted for transmitting and/or receiving single-carrier or multi-carrier modulated signals (e.g., including Complementary Code Keying (CCK), orthogonal frequency division multiplexing (OFDM), and/or Single-Carrier Frequency Division Multiple Access (SC-FDMA) symbols) although the configurations are not limited to any specific over-the-error interface or modulation scheme. The radio interface  635  may include, for example, a receiver  645  and/or a transmitter  650 . Radio interface  635  may include bias controls, a crystal oscillator, and/or one or more antennas  655 . In additional or alternative configurations, the radio interface  635  may use oscillators and/or one or more filters, as desired. 
     Baseband circuitry  640  may communicate with radio interface  635  to process, receive, and/or transmit signals and may include, for example, an Analog-To-Digital Converter (ADC) for down converting received signals with a Digital-To-Analog Converter (DAC)  660  for up converting signals for transmission. Further, baseband circuitry  640  may include a baseband or PHYsical layer (PHY) processing circuit for the PHY link layer processing of respective receive/transmit signals. Baseband circuitry  640  may include, for example, a Media Access Control (MAC) processing circuit  665  for MAC/data link layer processing. Baseband circuitry  640  may include a memory controller for communicating with MAC processing circuit  665  and/or a computing platform  600 , for example, via one or more interfaces  670 . 
     In some configurations, PHY processing circuit may include a frame construction and/or detection module, in combination with additional circuitry such as a buffer memory, to construct and/or deconstruct communication frames. Alternatively or in addition, MAC processing circuit  665  may share processing for certain of these functions or perform these processes independent of PHY processing circuit. In some configurations, MAC and PHY processing may be integrated into a single circuit. 
     The methods and systems here have distinct advantages and allow for managing uplink transmissions in a Multi-AP coordination scheme. The changing of the beamwidth eliminates at least some sounding requirements that create overhead for the APs. As such, the methods herein provide more efficient and less processing intensive ways of receiving interference-lessened uplink transmissions. 
     Example of the disclosure, for example, may be implemented as a computer process (method), a computing system, or as an article of manufacture, such as a computer program product or computer readable media. The computer program product may be a computer storage media readable by a computer system and encoding a computer program of instructions for executing a computer process. The computer program product may also be a propagated signal on a carrier readable by a computing system and encoding a computer program of instructions for executing a computer process. Accordingly, the present disclosure may be embodied in hardware and/or in software (including firmware, resident software, micro-code, etc.). In other words, example of the present disclosure may take the form of a computer program product on a computer-usable or computer-readable storage medium having computer-usable or computer-readable program code embodied in the medium for use by or in connection with an instruction execution system. A computer-usable or computer-readable medium may be any medium that can contain, store, communicate, propagate, or transport the program for use by or in connection with the instruction execution system, apparatus, or device. 
     The computer-usable or computer-readable medium may be, for example but not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, device, or propagation medium. More specific computer-readable medium examples (a non-exhaustive list), the computer-readable medium may include the following: an electrical connection having one or more wires, a portable computer diskette, a random access memory (RAM), a read-only memory (ROM), an Erasable Programmable Read-Only Memory (EPROM or Flash memory), an optical fiber, and a portable Compact Disc Read-Only Memory (CD-ROM). Node that the computer-usable or computer-readable medium could even be paper or another suitable medium upon which the program is printed, as the program can be electronically captured, via, for instance, optical scanning of the paper or other medium, then compiled, interpreted, or otherwise processed in a suitable manner, if necessary, and then stored in a computer memory. 
     While certain example of the disclosure have been described, other example may exist. Furthermore, although example of the present disclosure have been described as being associated with data stored in memory and other storage mediums, data can also be stored on or read from other types of computer-readable media, such as secondary storage devices, like hard disks, floppy disks, or a CD-ROM, a carrier wave from the Internet, or other forms of RAM or ROM. Further, the disclosed methods&#39; stages may be modified in any manner, including by reordering stages and/or inserting or deleting stages, without departing from the disclosure. 
     Furthermore, example of the disclosure may be practiced in an electrical circuit comprising discrete electronic elements, packaged or integrated electronic chips containing logic gates, a circuit utilizing a microprocessor, or on a single chip containing electronic elements or microprocessors. Example of the disclosure may also be practiced using other technologies capable of performing logical operations such as, for example, AND, OR, and NOT, including but not limited to, mechanical, optical, fluidic, and quantum technologies. In addition, example of the disclosure may be practiced within a general purpose computer or in any other circuits or systems. 
     Example of the disclosure may be practiced via a SOC where each or many of the element illustrated in  FIG.  1    may be integrated onto a single integrated circuit. Such a SOC device may include one or more processing units, graphics units, communications units, system virtualization units and various application functionality all of which may be integrated (or “burned”) onto the chip substrate as a single integrated circuit. When operating via an SOC, the functionality described herein with respect to example of the disclosure, may be performed via application-specific logic integrated with other components of computing device  600  on the single integrated circuit (chip). 
     Example of the present disclosure, for example, are described above with reference to block diagrams and/or operational illustrations of methods, systems, and computer program products according to example of the disclosure. The functions/acts noted in the blocks may occur out of the order as shown in any flowchart. For example, two blocks shown in succession may in fact be executed substantially concurrently or the blocks may sometimes be executed in the reverse order, depending upon the functionality/acts involved. 
     While the specification includes examples, the disclosure&#39;s scope is indicated by the following claims. Furthermore, while the specification has been described in language specific to structural features and/or methodological acts, the claims are not limited to the features or acts described above. Rather, the specific features and acts described above are disclosed as example for example of the disclosure.