Patent Publication Number: US-11652559-B2

Title: Method and system for Wi-Fi field-to-lab testing

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims priority to U.S. Provisional Application No. 63/106,940, titled “A Method and System for Field to Lab Capture,” filed on Oct. 29, 2020, which is hereby incorporated by reference. 
    
    
     TECHNICAL FIELD 
     This application relates generally to wireless and Wi-Fi field-to-lab testing. 
     BACKGROUND 
     Common problems in the wireless testing industry today pertains to the difficulty, time-consuming, costly, and reliability issues of testing real world scenarios in the real world. To remedy these issues, it is preferable to replicate real world phenomena in a lab setting, called field to lab replication. 
     Specifically, a significant problem is the difficulty to capture real world scenarios and be able to easily replicate them in a controlled environment. This problem is especially acute in more complicated service scenarios where multiple devices or possible device scenarios are involved. 
     For example, Wi-Fi mesh networks are difficult to replicate in a controlled environment because of the multitude of different kinds of homes and variety of methods for building Wi-Fi mesh systems into the homes. In particular, one could have a single router only, have one router and a mesh node, or more than one mesh node. 
     In particular, the root router connected to the internet could be anywhere in a home, and the first and second extenders could be placed in many different rooms within the home. Furthermore, there are hundreds if not thousands of different methods and locations for utilizing Wi-Fi devices in these homes including use of an iPad in the living room, use of an Android mobile phone while walking around the home or in the garage or driveway. 
     A particular subset of the problem is capturing the propagation experienced in a specific environment of interest such as a house, office, industrial building, open area, or mine. For example, houses are of different size, different room configurations, and are built with various construction materials and methodologies. Further, different types of furniture and moveable items are placed in a home which can cause a great variability in signal propagation in a home. Multiple different kinds of mesh networks can be built into these houses, therefore resulting in multiple propagation scenarios. 
     As a result, testing the foregoing scenarios in the field is time and cost prohibitive. Replicating these scenarios in a lab is time consuming and questions often remain whether a scenario has been reliability replicated. The limited selection of testing methodologies and lack of confidence in the available industry methodologies has resulted in a situation where many of the more complicated scenarios are simply not tested. The outcome is the ineffectiveness of routers and wireless services and subsequent unhappy consumers. 
     SUMMARY 
     Example embodiments described herein have innovative features, no single one of which is indispensable or solely responsible for their desirable attributes. The following description and drawings set forth certain illustrative implementations of the disclosure in detail, which are indicative of several exemplary ways in which the various principles of the disclosure may be carried out. The illustrative examples, however, are not exhaustive of the many possible embodiments of the disclosure. Without limiting the scope of the claims, some of the advantageous features will now be summarized. Other objects, advantages and novel features of the disclosure will be set forth in the following detailed description of the disclosure when considered in conjunction with the drawings, which are intended to illustrate, not limit, the invention. 
     An aspect of the invention is directed to a method for field-to-lab testing of a wireless device, comprising retrieving, with a computer operatively coupled to a non-transitory computer readable storage medium, (a) data representing a recording of a wireless field client device in a wireless field test environment and (b) data representing a physical configuration of the wireless field test environment. The wireless field test environment includes a mesh network comprising: a field wireless-root access point (AP); and a field wireless-extender AP in wireless communication with the field wireless-root AP, wherein: the data representing the recording includes wireless path-loss measurements between the field wireless-root AP and the wireless field client device and between the field wireless-extender AP and the wireless field client device, and the data representing the physical configuration of the wireless field test environment includes wireless path-loss measurements from the field wireless-root AP to the field wireless-extender AP and from the field wireless-extender AP to the field wireless-root AP. The method further comprises: sending one or more first control signals from the computer to a first programmable attenuator that is electrically coupled to a first signal line that provides a first data communication path between (a) a wireless laboratory client device located in a client electromagnetically-isolated chamber and (b) a laboratory wireless-root AP located in a root electromagnetically-isolated chamber, whereby the wireless laboratory client device and the laboratory wireless-root AP are in electrical communication to transmit root-client signals to each other; sending one or more second control signals from the computer to a second programmable attenuator that is electrically coupled to a second signal line that provides a second data communication path between (a) the wireless laboratory client device and (b) a laboratory wireless-extender AP located in an extender electromagnetically-isolated chamber, whereby the wireless laboratory client device and the laboratory wireless-extender AP are in electrical communication to transmit extender-client signals to each other; sending one or more third control signals from the computer to a third programmable attenuator that is electrically coupled to a third signal line that provides a third data communication path between (a) the laboratory wireless-root AP and (b) the laboratory wireless-extender AP, whereby the laboratory wireless-root AP and the laboratory wireless-extender AP are in electrical communication to transmit root-extender signals to each other; setting a first attenuation produced by the first programmable attenuator according to the first control signal(s); setting a second attenuation produced by the second programmable attenuator according to the second control signal(s); and setting a third attenuation produced by the third programmable attenuator according to the third control signal(s). The first and second attenuations simulates a field location of the wireless laboratory client device in the wireless field test environment. The third attenuation simulates the physical configuration of the wireless field test environment. 
     In one or more embodiments, the method further comprises setting (a) a signal strength of the root-extender signals and (b) a signal strength of the extender-client signals, wherein: the signal strength of the root-extender signals reproduces, from a perspective of the wireless laboratory client device, an effective distance between the wireless field client device and the field wireless-root AP at the field location of the wireless laboratory client device in the wireless field test environment, and the signal strength of the extender-client signals reproduces, from the perspective of the wireless laboratory client device, an effective distance between the wireless field client device and the field wireless-extender AP at the field location of the wireless laboratory client device in the wireless field test environment. In one or more embodiments, the method further comprises setting a signal strength of the root-extender signals, wherein the signal strength of the root-extender signals reproduces, from a perspective of the laboratory wireless-root AP, an effective distance between the field wireless-root AP and the field wireless-extender AP in the wireless field test environment. 
     In one or more embodiments, the root-client signals are root-client laboratory signals, the extender-client signals are extender-client laboratory signals, and the method further comprises: placing the wireless field client device at the field location in the wireless field test environment; while the wireless field client device is at the field location, repeatedly measuring with the wireless field client device: (a) a signal strength of root-client field wireless signals sent between the field wireless-root AP and the wireless field client device and (b) a signal strength of extender-client field wireless signals sent between the field wireless-extender AP and the wireless field client device; and storing signal strength measurements of the root-client field wireless signals and of the extender-client field wireless signals in non-transitory memory operatively coupled to the wireless field client device. 
     In one or more embodiments, the data representing the recording includes wireless path-loss measurements, as the wireless field client device is moved along a path in the wireless field test environment, between the field wireless-root AP and the wireless field client device and between the field wireless-extender AP and the wireless field client device, and the method further comprises: simultaneously varying (a) the first attenuation with respect to time produced by the first programmable attenuator according to the first control signals and (b) the second attenuation with respect to time produced by the second programmable attenuator according to the second control signals, wherein a simultaneous variation of the first and second attenuations with respect to time simulates a movement of the wireless laboratory client device along the path through the wireless field test environment. In one or more embodiments, the method further comprises simultaneously varying (a) a signal strength, with respect to time, of the root-client signals and (b) a signal strength, with respect to time, of the extender-client signals, wherein a simultaneous variation of the signal strength of the root-client signals and of the signal strength of the extender-client signals reproduces, from the perspective of the wireless laboratory client device, the movement of the wireless field client device along the path through the wireless field test environment. 
     In one or more embodiments, the root-client signals are root-client laboratory signals, the extender-client signals are extender-client laboratory signals, and the method further comprises: moving the wireless field client device along the path through the wireless field test environment; while moving the wireless field client device along the path, repeatedly measuring with the wireless field client device: (a) a signal strength of root-client field wireless signals sent between the field wireless-root AP and the wireless field client device and (b) a signal strength of extender-client field wireless signals sent between the field wireless-extender AP and the wireless field client device; and storing signal strength measurements of the root-client field wireless signals and of the extender-client field wireless signals in non-transitory memory operatively coupled to the wireless field client device. In one or more embodiments, the method further comprises: moving the wireless field client device to within a predetermined radius of the field wireless-root AP; while the wireless field client device is within the predetermined radius of the field wireless-root AP, measuring a signal strength of extender field wireless signals sent from the field wireless-extender AP to the field wireless-root AP; moving the wireless field client device to within a predetermined radius of the field wireless-extender AP; while the wireless field client device is within the predetermined radius of the field wireless-extender AP, measuring a signal strength of root field wireless signals sent from the field wireless-root AP to the field wireless-extender AP; and storing signal strength measurements of the root field wireless signals and of the extender field wireless signals in the non-transitory memory operatively coupled to the wireless field client device. In one or more embodiments, the path passes through the predetermined radius of the field wireless-root AP and the predetermined radius of the field wireless-extender AP. 
     In one or more embodiments, the field wireless-extender AP is a first field wireless-extender AP, the laboratory wireless-extender AP is a first laboratory wireless-extender AP, the extender-client signals are first-extender-client signals, the root-extender signals are root-first-extender signals, the extender electromagnetically-isolated chamber is a first extender electromagnetically-isolated chamber, the wireless field test environment includes a second field wireless-extender AP in wireless communication with the field wireless-root AP and the first wireless-extender AP, the data representing the recording further includes wireless path-loss measurements, as the wireless field client device is moved along the path, between the second field wireless-root AP and wireless field client device, between the second field wireless-extender AP and the wireless field client device, and between the first and second field wireless-root APs, the data representing the configuration of the wireless field test environment further includes wireless path-loss measurements from the field wireless-root AP to the second field wireless-extender AP, from the second field wireless-extender AP to the field wireless-root AP, from the first field wireless-extender AP to the second field wireless-extender AP, and second field wireless-extender AP to the first field wireless-extender AP, and the method further comprises: sending fourth control signals from the computer to a fourth programmable attenuator that is electrically coupled to a fourth signal line, the fourth signal line electrically coupling (a) the wireless laboratory client device and (b) a second laboratory wireless-extender AP located in a second extender electromagnetically-isolated chamber, whereby the wireless laboratory client device and the second laboratory wireless-extender AP are in electrical communication to transmit second-extender-client signals to each other; sending one or more fifth control signals from the computer to a fifth programmable attenuator that is electrically coupled to a fifth signal line, the fifth signal line electrically coupling (a) the laboratory wireless-root AP and (b) the second laboratory wireless-extender AP, whereby the laboratory wireless-root AP and the second laboratory wireless-extender AP are in electrical communication to transmit second-extender-root signals to each other; sending one or more sixth control signals from the computer to a sixth programmable attenuator that is electrically coupled to a sixth signal line, the sixth signal line electrically coupling (a) the first laboratory wireless-extender AP (b) the second laboratory wireless-extender AP, whereby the first laboratory wireless-extender AP and the second laboratory wireless-extender AP are in electrical communication to transmit first-extender-second-extender signals to each other; simultaneously varying (a) the first attenuation with respect to time, (b) the second attenuation with respect to time, and (c) a fourth attenuation with respect to time produced by the fourth programmable attenuator according to the fourth control signals; setting a fifth attenuation produced by the fifth programmable attenuator according to the fifth control signal(s); and setting a sixth attenuation produced by the sixth programmable attenuator according to the sixth control signal(s), wherein: the simultaneous variation of the first, second, and fourth attenuations with respect to time simulates the movement of the wireless laboratory client device along the path through the wireless field test environment, and the third, fifth, and sixth attenuations simulate the physical configuration of the wireless field test environment. 
     Another aspect of the invention is directed to a system for field-to-lab testing of a wireless device, comprising: a wireless laboratory client device located in a client electromagnetically-isolated chamber; a laboratory wireless-root access point (AP) located in a root electromagnetically-isolated chamber; a laboratory wireless-extender AP located in an extender electromagnetically-isolated chamber; a first signal line that provides a first data communication path between (a) the wireless laboratory client device and (b) the laboratory wireless-root AP; a first programmable attenuator electrically coupled to the first signal line; a second signal line that provides a second data communication path between (a) the wireless laboratory client device and (b) the laboratory wireless-extender AP; a second programmable attenuator electrically coupled to the second signal line; a third signal line that provides a third data communication path between (a) the laboratory wireless-root AP and (b) the laboratory wireless-extender AP; a third programmable attenuator electrically coupled to the third signal line; a computer in electrical communication with first, second, and third programmable attenuators, the computer operatively coupled to a non-transitory computer readable storage medium that includes (a) data representing a recording of a wireless field client device in a wireless field test environment and (b) data representing a physical configuration of the wireless field test environment, the wireless field test environment including: a field wireless-root AP; and a field wireless-extender AP in wireless communication with the field wireless-root AP. The data representing the recording includes wireless path-loss measurements between the field wireless-root AP and the wireless field client device and between the field wireless-extender AP and the wireless field client device. The data representing the physical configuration of the wireless field test environment includes wireless path-loss measurements between the field wireless-root AP and the field wireless-extender AP and between the field wireless-extender AP and the field wireless-root AP. The computer is configured to: send one or more first control signals to the first programmable attenuator to set a first attenuation produced by the first programmable attenuator, send one or more second control signals to the second programmable attenuator to set a second attenuation produced by the second programmable attenuator, and send one or more third control signals to the third programmable attenuator, wherein: the first and second attenuations simulates a field location of the wireless laboratory client device in the wireless field test environment, and the third attenuation simulates the physical configuration of the wireless field test environment. 
     In one or more embodiments, the first attenuation sets a signal strength of the root-extender signals, the second attenuation sets a signal strength of the extender-client signals, the third attenuation sets a signal strength of the root-extender signals, the signal strength of the root-extender signals reproduces, from a perspective of the wireless laboratory client device, an effective distance between the wireless field client device and the field wireless-root AP at the field location of the wireless laboratory client device in the wireless field test environment, the signal strength of the extender-client signals reproduces, from the perspective of the wireless laboratory client device, an effective distance between the wireless field client device and the field wireless-extender AP at the field location of the wireless laboratory client device in the wireless field test environment, and the signal strength of the root-extender signals reproduces, from a perspective of the laboratory wireless-root AP, an effective distance between the field wireless-root AP and the field wireless-extender AP in the wireless field test environment. 
     In one or more embodiments, the wireless field client device comprises a wireless link monitor. In one or more embodiments, the data representing the recording includes wireless path-loss measurements, as the wireless field client device is moved along a path in the wireless field test environment, between the field wireless-root AP and the wireless field client device and between the field wireless-extender AP and the wireless field client device, the first and second control signals cause the first and second programmable attenuators to simultaneously vary the first and second attenuations with respect to time, and a simultaneous variation of the first and second attenuations, with respect to time, simulates a movement of the wireless laboratory client device along the path through the wireless field test environment. 
     In one or more embodiments, the simultaneous variation of the first and second attenuations, with respect to time, causes a simultaneous variation of (a) a signal strength, with respect to time, of the root-client signals and (b) a signal strength, with respect to time, of the extender-client signals, and the simultaneous variation of (a) a signal strength, with respect to time, of the root-client signals and (b) a signal strength, with respect to time, of the extender-client signals reproduces, from the perspective of the wireless laboratory client device, a movement of the wireless field client device along the path through the wireless field test environment. 
     In one or more embodiments, the field wireless-extender AP is a first field wireless-extender AP, the laboratory wireless-extender AP is a first laboratory wireless-extender AP, the extender-client signals are first-extender-client signals, the root-extender signals are root-first-extender signals, the extender electromagnetically-isolated chamber is a first extender electromagnetically-isolated chamber, the wireless field test environment includes a second field wireless-extender AP in wireless communication with the field wireless-root AP and the first wireless-extender AP, the data representing the recording further includes wireless path-loss measurements, as the wireless field client device is moved along the path, between the second field wireless-root AP and the wireless field client device, between the first field wireless-extender AP and the wireless field client device, and between the field wireless-root AP and the wireless field client device, the data representing the configuration of the wireless field test environment further includes wireless path-loss measurements between the field wireless-root AP and the first field wireless-extender AP, between the field wireless-root AP and the second field wireless-extender AP, and between the first field wireless-extender AP and the second field wireless-extender AP, and the system further comprises: a second laboratory wireless-extender AP located in a second extender electromagnetically-isolated chamber, a fourth signal line that provides a data communication path between (a) the wireless laboratory client device and (b) the second laboratory wireless-extender AP, whereby the wireless laboratory client device and the second laboratory wireless-extender AP are in electrical communication to transmit second-extender-client signals to each other; a fourth programmable attenuator electrically coupled to the fourth signal line; a fifth signal line that provides a data communication path between (a) the laboratory wireless-root AP and (b) the second laboratory wireless-extender AP, whereby the laboratory wireless-root AP and the second laboratory wireless-extender AP are in electrical communication to transmit second-extender-root signals to each other; a fifth programmable attenuator electrically coupled to the fifth signal line, the fifth programmable attenuator producing a fifth attenuation; a sixth signal line that provides a data communication path between (a) the first laboratory wireless-extender AP and (b) the second laboratory wireless-extender AP, whereby the first laboratory wireless-extender AP and the second laboratory wireless-extender AP are in electrical communication to transmit first-extender-second-extender signals to each other. The computer is further configured to: send fourth control signals to the fourth programmable attenuator to vary a fourth programmable attenuation, with respect to time, produced by the fourth programmable attenuator; send one or more fifth control signals to the fifth programmable attenuator to set a fifth attenuation produced by the fifth programmable attenuator, and send one or more sixth control signals to the sixth programmable attenuator to set a sixth attenuation produced by the sixth programmable attenuator, wherein: the first, second, and fourth control signals cause the first, second, and fourth attenuations, respectively, to vary simultaneously, with respect to time, to simulate the movement of the wireless laboratory client device along the path through the wireless field test environment, and the third, fifth, and sixth attenuations simulate the physical configuration of the wireless field test environment. 
     In one or more embodiments, the system further comprises a first client antenna disposed in the client electromagnetically-isolated chamber, the first client antenna electrically coupled to the first signal line; a first root antenna disposed in the root electromagnetically-isolated chamber, the first root antenna electrically coupled to the first signal line; a second client antenna disposed in the client electromagnetically-isolated chamber, the second client antenna electrically coupled to the second signal line; a first extender antenna disposed in the extender electromagnetically-isolated chamber, the first extender antenna electrically coupled to the second signal line; a second root antenna disposed in the root electromagnetically-isolated chamber, the second root antenna electrically coupled to the third signal line; and a second extender antenna disposed in the extender electromagnetically-isolated chamber, the second extender antenna electrically coupled to the third signal line, whereby the wireless laboratory client device, the laboratory wireless-root AP, and the laboratory wireless-extender AP are in wireless communication with each other. 
     In one or more embodiments, the first signal line is electrically connected to a first port in the wireless laboratory client device and a first port in the laboratory wireless-root AP, the second signal line is electrically connected to a second port in the wireless laboratory client device and a first port in the laboratory wireless-extender AP, and the third signal line is electrically connected to a second port in the laboratory wireless-root AP and a second port in the laboratory wireless-extender AP, whereby the wireless laboratory client device, the laboratory wireless-root AP, and the laboratory wireless-extender AP are in wired communication with each other. 
     Yet another aspect of the invention is directed to a computer program product comprising computer-readable instructions that, when executed by a processor, cause the processor to: retrieve, with a computer operatively coupled to a non-transitory computer readable storage medium, (a) data representing a recording of a wireless field client device in a wireless field test environment and (b) data representing a physical configuration of the wireless field test environment, the wireless field test environment including a mesh network comprising: a field wireless-root access point (AP); and a field wireless-extender AP in wireless communication with the field wireless-root AP, wherein: the data representing the recording includes wireless path-loss measurements between the field wireless-root AP and the wireless field client device and between the field wireless-extender AP and the wireless field client device, and the data representing the physical configuration of the wireless field test environment includes wireless path-loss measurements from the field wireless-root AP to the field wireless-extender AP and from the field wireless-extender AP to the field wireless-root AP. The instructions further cause the processor to: send one or more first control signals from the computer to a first programmable attenuator that is electrically coupled to a first signal line that provides a first data communication path between (a) a wireless laboratory client device located in a client electromagnetically-isolated chamber and (b) a laboratory wireless-root AP located in a root electromagnetically-isolated chamber, whereby the wireless laboratory client device and the laboratory wireless-root AP are in electrical communication to transmit root-client signals to each other; send one or more second control signals from the computer to a second programmable attenuator that is electrically coupled to a second signal line that provides a second data communication path between (a) the wireless laboratory client device and (b) a laboratory wireless-extender AP located in an extender electromagnetically-isolated chamber, whereby the wireless laboratory client device and the laboratory wireless-extender AP are in electrical communication to transmit extender-client signals to each other; send one or more third control signals from the computer to a third programmable attenuator that is electrically coupled to a third signal line that provides a third data communication path between (a) the laboratory wireless-root AP and (b) the laboratory wireless-extender AP, whereby the laboratory wireless-root AP and the laboratory wireless-extender AP are in electrical communication to transmit root-extender signals to each other; set a first attenuation produced by the first programmable attenuator according to the first control signal(s); set a second attenuation produced by the second programmable attenuator according to the second control signal(s); and set a third attenuation produced by the third programmable attenuator according to the third control signal(s), wherein: the first and second attenuations simulates a field location of the wireless laboratory client device in the wireless field test environment, and the third attenuation simulates the physical configuration of the wireless field test environment. 
     In one or more embodiments, the data representing the recording includes wireless path-loss measurements, as the wireless field client device is moved along a path in the wireless field test environment, between the field wireless-root AP and the wireless field client device and between the field wireless-extender AP and the wireless field client device, and the instructions further cause the processor to: simultaneously vary (a) the first attenuation with respect to time produced by the first programmable attenuator according to the first control signals and (b) the second attenuation with respect to time produced by the second programmable attenuator according to the second control signals, wherein a simultaneous variation of the first and second attenuations with respect to time simulates a movement of the wireless laboratory client device along the path through the wireless field test environment. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       For a fuller understanding of the nature and advantages of the concepts disclosed herein, reference is made to the detailed description of preferred embodiments and the accompanying drawings. 
         FIGS.  1 A and  1 B  are flow charts of a method for recording wireless field client device in a field test environment according to alternative embodiments. 
         FIG.  2    illustrates an example path taken by a wireless link monitor through an example field-test environment. 
         FIG.  3    is a graph that includes example signal strength data of Wi-Fi signals from the mesh network nodes in the field test environment illustrated in  FIG.  2    as the wireless link monitor is moved along the example path. 
         FIG.  4    is a block diagram of a field-to-lab testing system according to an embodiment. 
         FIG.  5    is a flow chart of a method for field-to-lab testing a wireless device according to an embodiment. 
         FIG.  6    is a block diagram of a field-to-lab testing system according to another embodiment. 
         FIG.  7    is a flow chart of a method for field-to-lab testing a wireless device according to another embodiment. 
         FIG.  8    is a graph that illustrates maximum-achievable data throughput and actual data throughput of a test device. 
         FIG.  9    is a graph that illustrates the actual data throughput of a test device over multiple test runs. 
         FIG.  10    is a flow chart of a method for field-to-lab testing of a wireless device according to another embodiment 
         FIG.  11    is a flow chart of a method for field-to-lab testing a wireless device according to another embodiment 
     
    
    
     DETAILED DESCRIPTION 
     A client device (e.g., a wireless link monitor) is moved along a path in a field test environment containing mesh network nodes that produce a Wi-Fi mesh network. The client device measures the signal strength of the Wi-Fi signals sent from each mesh network node as the client device is moved along the path. The signal strength of the Wi-Fi signals sent from each mesh network node is converted into path-loss measurements based on the effective radiated power (e.g., ERP or EIRP) of each mesh network field node and the gain of the client device&#39;s antenna. These path-loss measurements are used to vary the attenuation of programmable attenuators in a field-to-lab test environment to simulate and/or reproduce the “experience” of the client device moving along the path. 
       FIGS.  1 A and  1 B  are flow charts of method  10 A,  10 B for recording wireless field client device in a field test environment according to alternative embodiments. In step  100 A of method  10 A, a wireless link monitor (e.g., a sniffer) is moved along a path in a field test environment containing mesh network nodes that produce a Wi-Fi mesh network. In step  100 B of method  10 B, the wireless link monitor (e.g., a sniffer) is moved to a location or room in the field test environment. 
       FIG.  2    illustrates an example path  200  taken by a wireless link monitor  210  through an example field-test environment  220 , which can be a house, a building, or another location. The path  200  can be straight or circuitous and preferably passes within a predetermined radius of (e.g., within 3 feet of) each mesh network node AP  230 - 232 . The wireless link monitor  210  can be held by a person (or another animal) that travels (e.g., walks or runs) along the path  200 , transported by a robot along the path  200 , or otherwise moved along the path  200 . The wireless link monitor  210  functions as a client device in the Wi-Fi mesh network and has the ability to collect data regarding the wireless signals sent from each mesh network node AP  230 - 232 . The Wi-Fi mesh network can include additional or fewer mesh network node APs  230 - 232  in other embodiments. 
     In another embodiment, the path  200  can be short and can only include pass through one or two rooms  225 , a portion of a room  225 , or one or two discrete locations in a room  225 . 
     Thus, in step  100 A, the wireless link monitor  210  can be moved along some or all of the path  200 . In step  100 B, the wireless link monitor  210  can be placed or held at a single location in a room  225 , moved within the room  225 , or placed in another location in the field-test environment  220 . For example, in step  100 B the wireless link monitor  210  can be placed or held at location D for all of step  100 B. In another example, the wireless link monitor  210  can start at location D and move along a path within room  225 , such as example path  250 . 
     In step  110 A, the wireless link monitor  210  is used to repeatedly (e.g., continuously such as multiple times per second) measure the strength or power (e.g., the received signal strength indicator (RSSI)) of the Wi-Fi signals received from each mesh network node AP  230 - 232  as the wireless link monitor  210  travels along the path  200 . In step  110 B, the wireless link monitor  210  is used to repeatedly (e.g., continuously such as multiple times per second) measure the strength or power (e.g., the received signal strength indicator (RSSI)) of the Wi-Fi signals received from each mesh network node AP  230 - 232  as the wireless link monitor  210  is located in a given room  225  (e.g., at location D), moved within a room  225  (e.g., along example path  250 ), or placed or held in another location in the field-test environment  220 . 
     During steps  110 A,  110 B, the wireless link monitor  210  can also measure other wireless parameters, such as data throughput, data rate, packet loss, as the wireless link monitor  210  travels along the path  200 . In some embodiments, the RSSI is a function of frequency, in which case the wireless link monitor  210  can simultaneously capture the RSSI for multiple frequencies. Additionally or alternatively, steps  100  and  110  can be repeated to capture RSSI data at different frequencies. For example, in order to capture the RSSI to determine the propagation loss accurately for all frequencies of interest, steps  100  and  110  would have to be replicated n times where n is the number of frequencies of interest. 
       FIG.  3    is a graph  30  that includes example RSSI data of the Wi-Fi signals from mesh network nodes AP  230 - 232  as the wireless link monitor  210  is moved along path  200  at a constant or substantially constant rate. The RSSI data is plotted versus time (e.g., seconds) for the root Wi-Fi signal  300 , for the first extender Wi-Fi signal  301 , and for the second extender Wi-Fi signal  302 . 
     As can be seen, the RSSI of the root Wi-Fi signal  300  is highest in the beginning, which corresponds to the initial portion of path  200  when the wireless link monitor  210  is relatively close to the root AP node  230 . The RSSI of the first extender Wi-Fi signal  301  is highest about halfway through the timed measurements, which corresponds to the middle portion of path  200  when the wireless link monitor  210  is relatively close to the first extender AP node  231 . The RSSI of the second extender Wi-Fi signal  302  is highest at the end of the timed measurements, which corresponds to the end of path  200  when the wireless link monitor  210  is relatively close to the second extender AP node  232 . The RSSI of each Wi-Fi signal  300 - 302  varies over time based on the relative physical distance (e.g., straight-line distance) between the wireless link monitor  210  and each mesh network node AP  230 - 232  and based on any obstructions between the wireless link monitor  210  and each mesh network node AP  230 - 232 , such as walls  240 , furniture, etc. The materials of the walls  240  and behind the walls  240  (e.g., insulation, pipes, wiring, etc.) may not be uniform, which can further impact the RSSI of each Wi-Fi signal  300 - 302 . 
     In step  120 , the wireless link monitor  210  is used to measure the strength or power (e.g., RSSI) of the Wi-Fi signals sent from each mesh network node AP  230 - 32  when the wireless link monitor is located within a predetermined radius of (e.g., within 3 feet of) each mesh network node AP. The strength of the Wi-Fi signals from each mesh network node AP at or approximately at the location each mesh network node AP (e.g., inter-AP RSSI measurements or readings) provides information on the configuration of the mesh network APs. For example, the inter-AP RSSI measurements correspond to the effective distance (e.g., effective radio-frequency (RF) distance) between each mesh network AP, which can be a combination of physical distance and one or more obstructions between each mesh network AP. Step  120  can be performed during or separately (e.g., at another time)from step  110 A. In  FIG.  2   , the path  200  passes next to (e.g., within 3 feet of) each mesh network node AP  230 - 232  which allows the wireless link monitor  210  to perform step  120  during step  110 . For example, the RSSI data collected in step  120  can be collected when the wireless link monitor  210  is located at path locations A, B, and C in path  200 , which corresponds to times A, B, and C, respectively, in  FIG.  3   . Step  120  is performed separately (e.g., at another time) from step  110 B. 
     In step  130 , the signal strength measurements collected in step  110 A or  110 B and step  120  are converted (e.g., using a computer) to wireless (e.g., RF) path-loss measurements using the effective radiated power (ERP) or the effective isotropic radiated power (EIRP) of each mesh network AP and the antenna gain of the wireless link monitor used to collect the strength of the Wi-Fi signals in steps  110 A,  110 B and  120 . The ERP/EIRP and the antenna gain of the wireless link monitor are generally known values of the devices. 
     In step  140 , the path-loss measurements are displayed on a display screen that is operatively coupled to the computer used in step  130 . Additionally or alternatively, the path-loss measurements are stored in computer memory such and/or in a non-transitory computer-readable medium, which in either case can represent a “recording” of the real-world field test. 
       FIG.  4    is a block diagram of a field-to-lab testing system  40  according to an embodiment. The system  40  includes a plurality of electromagnetically-isolated chambers  400  including a first electromagnetically-isolated chamber  401 , a second electromagnetically-isolated chamber  402 , and a third electromagnetically-isolated chamber  403 . A client device  420  (e.g., a station or STA) is disposed in the first electromagnetically-isolated chamber  401 , which can alternately be referred to as a client electromagnetically-isolated chamber. A root-wireless access point (AP)  430  is disposed in the second electromagnetically-isolated chamber  402 , which can alternately be referred to as a root electromagnetically-isolated chamber. The root AP  430  is a Wi-Fi AP that is coupled via a wired or wireless communication link to the internet  435 . A wireless-extender AP  440  is disposed in the third electromagnetically-isolated chamber  403 , which can alternately be referred to as an extender electromagnetically-isolated chamber. The root AP  430  and the extender AP  440  can be mesh Wi-Fi node APs that can produce a Wi-Fi network, such as in a home, in a business, or in another environment (e.g., indoors or outside). 
     The client device  420 , the root-wireless AP  430 , and the wireless-extender AP  440  are in wired and/or wireless communication with each other. In an embodiment, the client device  420  and the root-wireless AP  430  can be in wireless communication with each other via a first signal line  451  that is electrically coupled to a respective antenna  460  in each electromagnetically-isolated chamber  401 ,  402 . In an alternative embodiment, the first signal line  451  can be coupled to a respective port in the client device  420  and in the root-wireless AP  430  such that the client device  420  and the root-wireless AP  430  are in wired communication with each other. In yet another embodiment, one end of the first signal line  451  can be coupled to an antenna  460  to wireless communicate with the client device  420  or the root-wireless AP  430  and the other end of the first signal line  451  can be coupled to a port in the other device (i.e., the root-wireless AP  430  or the client device  420 ). The first signal line  451  can comprise a wired and/or a wireless communication path between the client device  420  and the root-wireless AP  430 . 
     In an embodiment, the client device  420  and the wireless-extender AP  440  are in wireless communication with each other via a second signal line  452  that is electrically coupled to a respective antenna  460  in each electromagnetically-isolated chamber  401 ,  403 . In an alternative embodiment, the second signal line  452  can be coupled to a respective port in the client device  420  and in the wireless-extender AP  440  such that the client device  420  and the wireless-extender AP  440  are in wired communication with each other. In yet another embodiment, one end of the second signal line  452  can be coupled to an antenna  460  to wireless communicate with the client device  420  or the wireless-extender AP  440  and the other end of the second signal line  452  can be coupled to a port in the other device (i.e., the wireless-extender AP  440  or the client device  420 ). The second signal line  452  can comprise a wired and/or a wireless communication path between the client device  420  and the wireless-extender AP  440 . 
     In an embodiment, the root-wireless AP  430  and the wireless-extender AP  440  are in wireless communication with each other via a third signal line  453  that is electrically coupled to a respective antenna  460  in each electromagnetically-isolated chamber  402 ,  403 . In an alternative embodiment, the third signal line  453  can be coupled to a respective port in the root-wireless AP  430  and in the wireless-extender AP  440  such that the root-wireless AP  430  and the wireless-extender AP  440  are in wired communication with each other. In yet another embodiment, one end of the third signal line  453  can be coupled to an antenna  460  to wireless communicate with the root-wireless AP  430  or the wireless-extender AP  440  and the other end of the third signal line  453  can be coupled to a port in the other device (i.e., the wireless-extender AP  440  or the root-wireless AP  430 ). The third signal line  453  can comprise a wired and/or a wireless communication path between the root-wireless AP  430  and the wireless-extender AP  440 . 
     The electromagnetically-isolated chambers  400  include RF feedthrough ports  190  that allow the signal lines  451 - 453  to pass while maintaining electromagnetic isolation within the electromagnetically-isolated chambers  400 . 
     A respective programmable attenuator  461 - 463  is electrically coupled to (e.g., in series with) each signal line  451 - 453 . The programmable attenuators  461 - 463  have a variable attenuation that can be set by respective control signals that are sent from a computer  470  that is in electrical communication with each programmable attenuator  461 - 463 . The computer  470  can be in wireless or wired communication with each programmable attenuator  461 - 463 . Wired communication links  481 - 483  between the computer  470  and the programmable attenuators  461 - 463 , respectively, are illustrated in  FIG.  4   , but any or all of the wired communication links  481 - 483  can be replaced with wireless communication links. 
     System  40  can be used to test the client device  420 , the root AP  430 , and/or the extender AP  440 . In-line or monitor wireless link monitors (e.g., sniffers)  495  can be included to detect data throughput, data rate, packet loss, and/or other wireless parameters during testing. 
     Additional details of system  40  are described with respect to  FIG.  5   , which is a flow chart of a method  50  for field-to-lab testing of a wireless device according to an embodiment. Method  50  can be performed using system  40  and/or embodied in instructions stored in a computer program product that cause a processor to perform method  50 . 
     In step  500 , the computer  470  retrieves from a non-transitory computer readable storage medium  472  (e.g., memory or a computer program product), operatively coupled to the computer  470 , data representing a recording of a path (e.g., path  200 ) through a wireless field test environment, such as the wireless field test environment recorded according to method  10 A. The data recording can comprise one or more files. In one embodiment, the data recording represents a continuous path through a wireless testing environment where the path passes within a predetermined radius of each wireless AP. In another embodiment, a first data file represents a continuous path through the wireless testing environment and a second data file represents the physical configuration of the mesh network APs in the wireless testing environment. 
     In step  510 , the computer  470  sends first control signals to the first programmable attenuator  461 , which is electrically coupled to the first signal line  451 . The first signal line  451  provides a first data communication path between the client device  420  and the root AP  430 . In an embodiment, the first signal line  451  is electrically coupled to a respective antenna  460  in the client and root electromagnetically-isolated chambers  401 ,  402 , respectively. The antennas  460  allow the client device  420  and the root AP  430  to be in wireless communication with each other while they are located in the client and root electromagnetically-isolated chambers  401 ,  402 , respectively, thereby allowing the client device  420  and the root AP  430  to transmit wireless signals (e.g., root-client signals) to one another. In another embodiment, the first signal line  451  is electrically coupled to a respective port in the client device  420  and in the root AP  430  to allow the client device  420  and the root AP  430  to be in wired communication with each other while they are located in the client and root electromagnetically-isolated chambers  401 ,  402 , respectively, thereby allowing the client device  420  and the root AP  430  to transmit wired signals (e.g., root-client signals) to one another. The computer  470  can send the first control signals wirelessly or through a wired communication link such as wired communication link  481 . 
     In step  520 , the computer  470  sends second control signals to the second programmable attenuator  462 , which is electrically coupled to the second signal line  452 . The second signal line  452  provides a second data communication path between the client device  420  and the extender AP  440 . In an embodiment, the second signal line  452  is electrically coupled to a respective antenna  460  in the client and extender electromagnetically-isolated chambers  401 ,  403 , respectively. The antennas  460  allow the client device  420  and the extender AP  440  to be in wireless communication with each other while they are located in the client and root electromagnetically-isolated chambers  401 ,  402 , respectively, thereby allowing the client device  420  and the extender AP  440  to transmit wireless signals (e.g., extender-client signals) to one another. In another embodiment, the second signal line  452  is electrically coupled to a respective port in the client device  420  and in the extender AP  440  to allow the client device  420  and the extender AP  440  to be in wired communication with each other while they are located in the client and root electromagnetically-isolated chambers  401 ,  402 , respectively, thereby allowing the client device  420  and the extender AP  440  to transmit wired signals (e.g., extender-client signals) to one another. The computer  470  can send the second control signals wirelessly or through wired communication link  482 . 
     In step  530 , the computer  470  sends one or more third control signals to the third programmable attenuator  463 , which is electrically coupled to the third signal line  453 . The third signal line  453  provides a third data communication path between the root AP  430  and the extender AP  440 . In an embodiment, the third signal line  453  is electrically coupled to a respective antenna  460  in the root and extender electromagnetically-isolated chambers  402 ,  403 , respectively. The antennas  460  allow the root AP  430  and the extender AP  440  to be in wireless communication with each other while they are located in the root and extender electromagnetically-isolated chambers  402 ,  403 , respectively, thereby allowing the root AP  430  and the extender AP  440  to transmit wireless signals (e.g., root-extender signals) to one another. In another embodiment, the third signal line  453  is electrically coupled to a respective port in the root AP  430  and in the extender AP  440  to allow the root AP  430  and the extender AP  440  to be in wired communication with each other while they are located in the client and root electromagnetically-isolated chambers  401 ,  402 , respectively, thereby allowing the root AP  430  and the extender AP  440  to transmit wired signals (e.g., root-extender signals) to one another. The computer  470  can send the third control signals wirelessly or through wired communication link  483 . 
     The first, second, and third control signals sent in steps  510 - 530  are produced by the computer  470  using the path-loss data in the wireless test environment recording retrieved in step  500 . 
     In step  540  (via placeholder A), the attenuation of the first and second programmable attenuators  461 ,  462  is simultaneously and independently varied based on the first and second control signals, respectively. The variation in the attenuation of the first programmable attenuator  461  causes the signal strength or power (e.g., the RSSI) of the wired or wireless signals sent between the root AP  430  and the client device  420  to be varied accordingly. The variation in the attenuation of the second programmable attenuator  462  causes the signal strength or power (e.g., RSSI) of the wired or wireless signals sent between the extender AP  440  and the client device  420  to be varied accordingly. 
     In step  550 , the simultaneous variation in attenuation of the first and second programmable attenuators  461 ,  462  and the corresponding simultaneous signal strength variation of the wired or wireless signals between the root AP  430  and the client device  420  and between the extender AP  440  and the client device  420  simulates and/or reproduces the path-loss measurements recorded as the wireless link monitor  210  was moved in the field test environment  220 . Additionally or alternatively, the simultaneous signal strength variation of the wired or wireless signals sent between the root AP  430  and the client device  420  and/or between the extender AP  440  and the client device  420  can simulate and/or reproduce one or more physical obstructions between the client device (e.g., wireless link monitor  210 ) and the root AP  230  and/or between the client device (e.g., wireless link monitor  210 ) and the extender AP  231 , respectively, that occurred as the client device (e.g., wireless link monitor  210 ) was moved along path  200  in the field test environment  220 . 
     The simultaneous signal strength variation of the wired or wireless signals transmitted between the root AP  430  and the client device  420  and between the extender AP  440  and the client device  420  can reproduce, from the perspective of the client device  420 , the movement of the wireless link monitor  210  along the path  200  in the field test environment  220 . For example, the simultaneous signal strength variation of the wired or wireless signals between the root AP  430  and the client device  420  and between the extender AP  440  and the client device  420  can cause the client device  420  to “experience” the testing conditions of the field test environment  220  while being under the controlled conditions of the field-to-lab testing system  40 . 
     The simultaneous variation in attenuation of the first and second programmable attenuators  461 ,  462  and the corresponding simultaneous signal strength variation of the wired or wireless signals between the root AP  430  and the client device  420  and between the extender AP  440  and the client device  420  can reproduce, from the perspective of the client device  420 , the movement of the wireless link monitor  210  along the path  200  in the field test environment  220  at the same speed that the wireless link monitor  210  travelled along the path  200  or at a different (faster or slower) speed. In another embodiment, the attenuation of the first and second programmable attenuators  461 ,  462  can be set to reproduce any discrete point or location along the path  200 , which can reproduce a stationary position of the wireless link monitor  210  at any point/location along the path  200 , such as a room  225  or one or more discrete locations/positions in a room  225  (e.g., location D). 
     In step  560 , the attenuation of the third programmable attenuator  463  is set based on the third control signal(s). The attenuation of the third programmable attenuator  463  causes the signal strength or power (e.g., the RSSI) of the wired or wireless signals sent between the root AP  430  and the extender AP  440  to be set accordingly. In step  570 , the signal strength of the wired or wireless signals between the root AP  430  and the extender AP  440  simulates and/or reproduces the physical configuration of the field test environment (e.g., the physical distance and/or one or more physical obstructions between the root AP  230  and the extender AP  231  in the field test environment  220 ). The physical distance and/or one or more physical obstructions between the root AP  230  and the extender AP  231  can be an effective distance (e.g., an effective RF distance) between the root AP  230  and the extender AP  231 . Thus, the signal strength or power of the wired or wireless signals sent between each mesh network node  430 ,  440  reproduces the physical configuration of the mesh network nodes  230 ,  231  in the field test environment  220 . 
     The signal strength of the wired or wireless signals transmitted between the root AP  430  and the extender AP  440  can reproduce, from the perspective of the root AP  230 , the effective distance between the root AP  230  and the extender AP  231 , which allows the field-to-lab testing system  40  to reproduce the same wireless mesh configuration as in the field test environment  220 . 
     System  40  and method  50  can be extended to additional mesh nodes. For example, system  60  in  FIG.  6    includes three mesh nodes. In system  60 , extender AP  440  is a first extender AP located in a first extender electromagnetically-isolated chamber  403 , and system  60  further includes a second extender AP  650  located in a second extender electromagnetically-isolated chamber  604 . The client device  420 , the root-wireless AP  430 , the first wireless-extender AP  440 , and the second wireless-extender AP  650  can be in wireless or wired communication with each other. The client device  420 , the root-wireless AP  430 , and the first wireless-extender AP  440  are in wireless or wired communication with each other in the same manner as described with respect to system  40  and method  50 , which is not repeated here for the sake of brevity. 
     In an embodiment, the client device  420  and the second wireless-extender AP  650  are in wireless communication with each other via a fourth signal line  654  that is electrically coupled to a respective antenna  460  in each electromagnetically-isolated chamber  401 ,  604 . In an alternative embodiment, the fourth signal line  654  can be coupled to a respective port in the client device  420  and in the second wireless-extender AP  650  such that the client device  420  and the second wireless-extender AP  650  are in wired communication with each other. In yet another embodiment, one end of the fourth signal line  654  can be coupled to an antenna  460  in electromagnetically-isolated chamber  401  or  604  to wirelessly communicate with the client device  420  or with the second wireless-extender AP  650 , respectively, and the other end of the fourth signal line  654  can be coupled to a port in the other device (i.e., the second wireless-extender AP  650  or the client device  420 ). The fourth signal line  654  can comprise a wired and/or a wireless data communication path between the root-wireless AP  430  and the wireless-extender AP  440 . 
     In an embodiment, the root-wireless AP  430  and the second wireless-extender AP  650  are in wireless communication with each other via a fifth signal line  655  that is electrically coupled to a respective antenna  460  in each electromagnetically-isolated chamber  402 ,  604 . In an alternative embodiment, the fifth signal line  655  can be coupled to a respective port in the root-wireless AP  430  and in the second wireless-extender AP  650  such that the root-wireless AP  430  and the second wireless-extender AP  650  are in wired communication with each other. In yet another embodiment, one end of the fifth signal line  655  can be coupled to an antenna  460  in electromagnetically-isolated chamber  402  or  604  to wireless communicate with the root-wireless AP  430  or the second wireless-extender AP  650 , respectively, and the other end of the fifth signal line  655  can be coupled to a port in the other device (i.e., the second wireless-extender AP  650  or the root-wireless AP  430 ). The fifth signal line  655  can comprise a wired and/or a wireless data communication path between the root-wireless AP  430  and the second wireless-extender AP  650 . 
     In an embodiment, the first wireless-extender AP  440  and the second wireless-extender AP  650  are in wireless communication with each other via a sixth signal line  656  that is electrically coupled to a respective antenna  460  in each electromagnetically-isolated chamber  403 ,  604 . In an alternative embodiment, the sixth signal line  656  can be coupled to a respective port in the first wireless-extender AP  440  and in the second wireless-extender AP  650  such that the first wireless-extender AP  440  and the second wireless-extender AP  650  are in wired communication with each other. In yet another embodiment, one end of the sixth signal line  656  can be coupled to an antenna  460  in electromagnetically-isolated chamber  403  or  604  to wireless communicate with the first wireless-extender AP  440  or the second wireless-extender AP  650 , respectively, and the other end of the sixth signal line  656  can be coupled to a port in the other device (i.e., the second wireless-extender AP  650  or the first wireless-extender AP  440 ). The sixth signal line  656  can comprise a wired and/or a wireless data communication path between the first wireless-extender AP  440  and the second wireless-extender AP  650 . 
     A respective programmable attenuator  664 - 666  is electrically coupled to (e.g., in series with) each signal line  654 - 656 . The programmable attenuators  664 - 666  can be the same as programmable attenuators  461 - 463 . The variable attenuation of the programmable attenuators  664 - 666  can be set by respective control signals that are sent from the computer  470  that is in electrical communication with each programmable attenuator  664 - 666 . An example wired communication link  685  between the computer  470  and fifth programmable attenuator  665  is illustrated in  FIG.  6   . The wired communication links between the computer  470  and fourth and sixth programmable attenuators  264 ,  266  are not illustrated in  FIG.  6    for clarity purposes only. Any or all of the wired communication links can be replaced with wireless communication links. Wired communication links  481 - 483  are not illustrated in  FIG.  6    for clarity purposes only. 
     System  60  can be used to test the client device  420 , the root AP  430 , the first extender AP  440 , and/or the second extender AP  650 . 
     Additional details of system  60  are described with respect to  FIG.  7   , which is a flow chart of a method  70  for testing a wireless device according to an embodiment. Method  70  can be performed using system  60  and/or embodied in instructions stored in a computer program product that cause a processor to perform method  70 . Steps  500 - 530  are the same as described above except that the extender AP  440  is a first extender AP  440  disposed in a first extender electromagnetically-isolated chamber  403 . 
     In step  740  (via placeholder A), the computer  470  sends fourth control signals to the fourth programmable attenuator  664 , which is electrically coupled to the fourth signal line  654 . The fourth signal line  654  provides a fourth data communication path between the client device  420  and the second extender AP  650 . In an embodiment, the fourth signal line  654  is electrically coupled to a respective antenna  460  in the client and second extender electromagnetically-isolated chambers  401 ,  604 , respectively. The antennas  460  and the fourth signal line  654  allow the client device  420  and the second extender AP  650  to be in wireless communication with each other while they are located in the client and second extender electromagnetically-isolated chambers  401 ,  604 , respectively, thereby allowing the client device  420  and the second extender AP  650  to transmit wireless signals (e.g., second extender-client signals) to one another. In another embodiment, the fourth signal line  654  is electrically coupled to a respective port in the client device  420  and in the second extender AP  650  to allow the client device  420  and the second extender AP  650  to be in wired communication with each other while they are located in the client and second extender electromagnetically-isolated chambers  401 ,  604 , respectively, thereby allowing the client device  420  and the second extender AP  650  to transmit wired signals (e.g., second extender-client signals) to one another. The computer  470  can send the fourth control signals wirelessly or through a wired communication link. 
     In step  750 , the computer  470  sends one or more fifth control signals to the fifth programmable attenuator  665 , which is electrically coupled to the fifth signal line  655 . The fifth signal line  654  provides a fifth data communication path between the root AP  430  and the second extender AP  650 . In an embodiment, the fifth signal line  655  is electrically coupled to a respective antenna  460  in the root and second extender electromagnetically-isolated chambers  402 ,  604 , respectively. The antennas  460  and the fifth signal line  655  allow the root AP  430  and the second extender AP  650  to be in wireless communication with each other while they are located in the root and second extender electromagnetically-isolated chambers  402 ,  604 , respectively, thereby allowing the root AP  430  and the second extender AP  650  to transmit wireless signals (e.g., root-second-extender signals) to one another. In another embodiment, the fifth signal line  655  is electrically coupled to a respective port in the root AP  430  and in the second extender AP  650  to allow the root AP  430  and the second extender AP  650  to be in wired communication with each other while they are located in the root and second extender electromagnetically-isolated chambers  402 ,  604 , respectively, thereby allowing the root AP  430  and the second extender AP  650  to transmit wired signals (e.g., root-second-extender signals) to one another. The computer  470  can send the fifth control signal(s) wirelessly or through wired communication link  685 . 
     In step  760 , the computer  470  sends one or more sixth control signals to the sixth programmable attenuator  666 , which is electrically coupled to the sixth signal line  656 . The sixth signal line  656  provides a sixth data communication path between the first extender AP  440  and the second extender AP  650 . In an embodiment, the sixth signal line  656  is electrically coupled to a respective antenna  460  in the first and second extender electromagnetically-isolated chambers  403 ,  604 , respectively. The antennas  460  and the sixth signal line  655  allow the first extender AP  440  and the second extender AP  650  to be in wireless communication with each other while they are located in the first and second extender electromagnetically-isolated chambers  403 ,  604 , respectively, thereby allowing the first extender AP  440  and the second extender AP  650  to transmit wireless signals (e.g., first-second-extender signals) to one another. In another embodiment, the sixth signal line  656  is electrically coupled to a respective port in the first extender AP  440  and in the second extender AP  650  to allow the first extender AP  440  and the second extender AP  650  to be in wired communication with each other while they are located in the first and second extender electromagnetically-isolated chambers  403 ,  604 , respectively, thereby allowing the first extender AP  440  and the second extender AP  650  to transmit wired signals (e.g., first-second-extender signals) to one another. The computer  470  can send the sixth control signal(s) wirelessly or through a wired communication link. 
     The control signals sent in steps  510 - 530  and in steps  740 - 760  are produced by the computer  470  using the path-loss data in the wireless test environment recording retrieved in step  500 . 
     In step  770  (via placeholder B), the attenuations of the first, second, and fourth programmable attenuators  461 ,  462 ,  664  are simultaneously and independently varied based on the first, second, and fourth control signals, respectively. The variation in the attenuation of the first programmable attenuator  461  causes the signal strength or power (e.g., RSSI) of the wired or wireless signals sent between the root AP  430  and the client device  420  to be varied accordingly. The variation in the attenuation of the second programmable attenuator  462  causes the signal strength or power (e.g., RSSI) of the wired or wireless signals sent between the first extender AP  440  and the client device  420  to be varied accordingly. The variation in the attenuation of the fourth programmable attenuator  664  causes the signal strength or power (e.g., RSSI) of the wired or wireless signals sent between the second extender AP  650  and the client device  420  to be varied accordingly. 
     In step  780 , the simultaneous variation in attenuation of the first, second, and fourth programmable attenuators  461 ,  462 ,  664  and the corresponding simultaneous signal strength variation of the wireless signals sent between the root AP  430  the client device  420 , between the first extender AP  440  and the client device  420 , and between the second extender AP  650  and the client device  420 , respectively, simulates and/or reproduces the path-loss measurements recorded during as the client device (e.g., wireless link monitor  210 ) was moved along path  200  in the field test environment  220 . Additionally or alternatively, the corresponding simultaneous signal strength variation of the wired or wireless signals sent between the root AP  430  the client device  420 , between the first extender AP  440  and the client device  420 , and between the second extender AP  650  and the client device  420 , can simulate and/or reproduce one or more physical obstructions between the client device (e.g., wireless link monitor) and the root AP  230 , between the client device (e.g., wireless link monitor) and the first extender AP  231 , and/or between the client device (e.g., wireless link monitor) and the second extender AP  232 , respectively, that occurred as the client device (e.g., wireless link monitor  210 ) was moved along path  200  in the field test environment  220 . 
     The simultaneous signal strength variation of the wired or wireless signals transmitted between the root AP  430  and the client device  420 , between the first extender AP  440  and the client device  420 , and between the second extender AP  650  and the client device  420  can reproduce, from the perspective of the client device  420 , the movement of the wireless link monitor  210  along the path  200  in the field test environment  220 . For example, the simultaneous signal strength variation of the wired or wireless signals between the root AP  430  and the client device  420 , between the first extender AP  440  and the client device  420 , and between the second extender AP  650  and the client device  420  can cause the client device  420  to “experience” the testing conditions of the field test environment  220  while being under the controlled conditions of the field-to-lab testing system  60 . 
     In step  790 , the attenuation of the third, fifth, and sixth programmable attenuators  463 ,  665 ,  666  is set based on the third, fifth, and sixth control signals, respectively. The attenuation of the third programmable attenuator  463  causes the signal strength or power (e.g., the RSSI) of the wireless signals between the root AP  430  and the first extender AP  440  to be set accordingly. The attenuation of the fifth programmable attenuator  665  causes the signal strength or power (e.g., the RSSI) of the wireless signals sent between the root AP  430  and the second extender AP  650  to be set accordingly. The attenuation of the sixth programmable attenuator  666  causes the signal strength or power (e.g., the RSSI) of the wired or wireless signals sent between the first extender AP  440  and the second extender AP  650  to be set accordingly. 
     In step  795 , the signal strength or power of the wired or wireless signals sent between the root AP  430  and the first extender AP  440  simulates and/or reproduces the physical distance and/or one or more physical obstructions (e.g., the effective distance) between the root AP  230  and the first extender AP  231  in the field test environment  220 . The signal strength or power of the wired or wireless signals sent between the root AP  430  and the second extender AP  650  simulates and/or reproduces the physical distance and/or one or more physical obstructions between the root AP  230  and the second extender AP  232  in the field test environment  220 . The signal strength or power of the wired or wireless signals sent between the first extender AP  440  and the second extender AP  650  simulates and/or reproduces the physical distance and/or one or more physical obstructions between the first extender AP  231  and the second extender AP  232  in the field test environment  220 . Thus, the signal strength or power of the wired or wireless signals sent between each mesh network node  430 ,  440 ,  650  reproduces the configuration of the mesh network nodes  230 - 232  in the field test environment  220 . 
     The signal strength of the wired or wireless signals transmitted between the root AP  430  and the first extender AP  440 , between the root AP  430  and the second extender AP  650 , and between the first and second extender APs  440 ,  650  can reproduce, from the perspective of the root AP  230 , the effective distance between the root AP  230  and the first extender AP  231  and between the root AP  230  and the second extender AP  232 , which allows the field-to-lab testing system  60  to reproduce the same wireless mesh configuration as in the field test environment  220 . 
     The wireless link monitors  210 ,  495  can measure data throughput and data rate, as discussed above. In an embodiment, the data throughput and/or data rate of the client device  420  using field-to-lab testing system  40 ,  60  during the simulated movement along the path  200  can be compared to the theoretical maximum-achievable data throughput and/or theoretical maximum-achievable data rate, as measured by the wireless link monitor  210  in the field test environment  220 , to determine the performance of the device-under-test (e.g., client device  420 , root AP  430 , etc.). Since the wireless link monitor  210  can simultaneously measure the data throughput and/or data rate from each mesh network node  230 - 232  in the field test environment  220 , the theoretical maximum-achievable data throughput and/or theoretical maximum-achievable data rate is the maximum of the data throughputs and/or data rates at any given time from any of the mesh network node  230 - 232 . For example, referring to  FIG.  3   , the maximum-achievable data throughput  800  for all mesh network nodes  230 - 232  as the wireless link monitor  210  is moved along the path  200  in in the field test environment  220  is illustrated in  FIG.  8   . The achievable data throughput  810  available to the client device  420  can then be compared as a performance measure of the device-under-test (e.g., client device  420  and/or mesh network node  430 ,  440 ,  650 ) in system  40 ,  60 . 
     Performance can also be characterized across test runs along path  200  using field-to-lab testing system  40 ,  60 , which can indicate statistical and/or run-to-run variations. For example,  FIG.  9    illustrates a graph  90  of data throughput available to the client device versus time on test runs  901 - 903 . Time period  910  indicates a run-to-run variation that appears to occur when the client device is simulated to appear close to the second extender AP node  232 . 
       FIG.  10    is a flow chart of a method  1000  for field-to-lab testing of a wireless device according to another embodiment. Method  1000  can be performed using system  40  and/or embodied in instructions stored in a computer program product that cause a processor to perform method  1000 . 
     In step  1001 , the computer  470  retrieves from a non-transitory computer readable storage medium  472  (e.g., memory or a computer program product), operatively coupled to the computer  470 , data representing a recording of a field location, such as a room, in a wireless field test environment. For example, the recording can represent location D in room  225  and/or path  250  in room  225  in field test environment  220 , which can be recorded according to method  10 B. The data recording can comprise one or more files. For example, the data recording can include a first data file that represents a room or location in a wireless testing environment and a second data file represents the physical configuration of the mesh network APs in the wireless testing environment. 
     In step  1010 , the computer  470  sends one or more first control signals to the first programmable attenuator  461 , which is electrically coupled to the first signal line  451 . The first signal line  451  provides a first data communication path between the client device  420  and the root AP  430  in the client and root electromagnetically-isolated chambers  401 ,  402 , respectively, such that they are in wireless or wired communication with each other, as discussed above. 
     In step  1020 , the computer  470  sends one or more second control signals to the second programmable attenuator  462 , which is electrically coupled to the second signal line  452 . The second signal line  452  provides a second data communication path between the client device  420  and the extender AP  440  in the client and extender electromagnetically-isolated chambers  401 ,  403 , respectively, such that they are in wireless or wired communication with each other, as discussed above. 
     In step  1030 , the computer  470  sends one or more third control signals to the third programmable attenuator  463 , which is electrically coupled to the third signal line  453 . The third signal line  453  provides a third data communication path between the root AP  430  and the extender AP  440  in the root and extender electromagnetically-isolated chambers  402 ,  403 , respectively, such that they are in wireless or wired communication with each other, as discussed above. 
     In step  1040 , the attenuation of the first and second programmable attenuators  461 ,  462  is set based on the first and second control signals. The attenuation of the first programmable attenuator  461  causes the signal strength or power (e.g., the RSSI) of the wired or wireless signals sent between the root AP  430  and the client device  420  to be set accordingly. The attenuation of the second programmable attenuator  462  causes the signal strength or power (e.g., RSSI) of the wired or wireless signals sent between the extender AP  440  and the client device  420  to be set accordingly. 
     In step  1050 , the attenuation of the first and second programmable attenuators  461 ,  462  and the corresponding signal strength setting of the wired or wireless signals between the root AP  430  and the client device  420  and between the extender AP  440  and the client device  420  simulates and/or reproduces, from the perspective of the client device  420 , the field location (e.g., of the wireless link monitor  210 ) in the field test environment  220 . Additionally or alternatively, the corresponding signal strength setting of the wired or wireless signals of the wired or wireless signals sent between the root AP  430  and the client device  420  and/or between the extender AP  440  and the client device  420  can simulate and/or reproduce the effective distance (e.g., effective RF distance) between the wireless link monitor  210  and the root AP  230  and/or between the wireless link monitor  210  and the extender AP  231 , respectively, at the field location of the wireless link monitor  210  in the field test environment  220 . 
     In step  1060 , the attenuation of the third programmable attenuator  463  is set based on the third control signal(s). The attenuation of the third programmable attenuator  463  causes the signal strength or power (e.g., the RSSI) of the wired or wireless signals sent between the root AP  430  and the extender AP  440  to be set accordingly. In step  1070 , the signal strength of the wired or wireless signals between the root AP  430  and the extender AP  440  simulates and/or reproduces the physical configuration of the field test environment (e.g., the physical distance and/or one or more physical obstructions between the root AP  230  and the extender AP  231  in the field test environment  220 ). The physical distance and/or one or more physical obstructions between the root AP  230  and the extender AP  231  can be an effective distance (e.g., an effective RF distance) between the root AP  230  and the extender AP  231 . Thus, the signal strength or power of the wired or wireless signals sent between each mesh network node  430 ,  440  reproduces the physical configuration of the mesh network nodes  230 ,  231  in the field test environment  220 . 
     The first, second, and third control signals sent in steps  1010 - 1030  are produced by the computer  470  using the path-loss data in the wireless test environment recording retrieved in step  1001 . 
     The signal strength of the wired or wireless signals transmitted between the root AP  430  and the extender AP  440  can reproduce, from the perspective of the root AP  230 , the effective distance between the root AP  230  and the extender AP  231 , which allows the field-to-lab testing system  40  to reproduce the same wireless mesh configuration as in the field test environment  220 . 
       FIG.  11    is a flow chart of a method  1100  for field-to-lab testing a wireless device according to another embodiment. Method  1000  can be performed using system  60  and/or embodied in instructions stored in a computer program product that cause a processor to perform method  1100 . Steps  1001 - 1030  are the same as described above except that the extender AP  440  is a first extender AP  440  disposed in a first extender electromagnetically-isolated chamber  403 . 
     In step  1140  (via placeholder A), the computer  470  sends fourth control signals to the fourth programmable attenuator  664 , which is electrically coupled to the fourth signal line  654 . The fourth signal line  654  provides a fourth data communication path between the client device  420  and the second extender AP  650  in the client and second extender electromagnetically-isolated chambers  401 ,  604 , respectively, such that they are in wireless or wired communication with each other, as discussed above. 
     In step  1150 , the computer  470  sends one or more fifth control signals to the fifth programmable attenuator  665 , which is electrically coupled to the fifth signal line  655 . The fifth signal line  654  provides a fifth data communication path between the root AP  430  and the second extender AP  650  in the root and second extender electromagnetically-isolated chambers  402 ,  604 , respectively, such that they are in wireless or wired communication with each other, as discussed above. 
     In step  1160 , the computer  470  sends one or more sixth control signals to the sixth programmable attenuator  666 , which is electrically coupled to the sixth signal line  656 . The sixth signal line  656  provides a sixth data communication path between the first extender AP  440  and the second extender AP  650  in the first and second extender electromagnetically-isolated chambers  403 ,  604 , respectively, such that they are in wireless or wired communication with each other, as discussed above. 
     In step  1170 , the attenuation of the first, second, and fourth programmable attenuators  461 ,  462 ,  664  is set based on the first, second, and fourth control signals, respectively. The attenuation of the first programmable attenuator  461  causes the signal strength or power (e.g., the RSSI) of the wired or wireless signals sent between the root AP  430  and the client device  420  to be set accordingly. The attenuation of the second programmable attenuator  462  causes the signal strength or power (e.g., RSSI) of the wired or wireless signals sent between the extender AP  440  and the client device  420  to be set accordingly. The attenuation of the fourth programmable attenuator  664  causes the signal strength or power (e.g., RSSI) of the wired or wireless signals sent between the client device  420  and the second extender AP  650  to be set accordingly. 
     In step  1180 , the attenuation of the first, second, and fourth programmable attenuators  461 ,  462 ,  664  and the corresponding signal strength setting of the wired or wireless signals between the root AP  430  and the client device  420 , between the extender AP  440  and the client device  420 , and between the client device  420  and the second extender AP  650  simulates and/or reproduces, from the perspective of the client device  420 , the field location (e.g., of the wireless link monitor  210 ) in the field test environment  220 . Additionally or alternatively, the corresponding signal strength setting of the wired or wireless signals of the wired or wireless signals sent between the root AP  430  and the client device  420 , between the extender AP  440  and the client device  420 , and/or between the client device  420  and the second extender AP  650  can simulate and/or reproduce the effective distance (e.g., effective RF distance) between the wireless link monitor  210  and the root AP  230 , between the wireless link monitor  210  and the extender AP  231 , and/or between the client device  420  and the second extender AP  650 , respectively, at the field location of the wireless link monitor  210  in the field test environment  220 . 
     In step  1190 , the attenuation of the third, fifth, and sixth programmable attenuators  463 ,  665 ,  666  is set based on the third, fifth, and sixth control signals, respectively. The attenuation of the third programmable attenuator  463  causes the signal strength or power (e.g., the RSSI) of the wireless signals between the root AP  430  and the first extender AP  440  to be set accordingly. The attenuation of the fifth programmable attenuator  665  causes the signal strength or power (e.g., the RSSI) of the wireless signals sent between the root AP  430  and the second extender AP  650  to be set accordingly. The attenuation of the sixth programmable attenuator  666  causes the signal strength or power (e.g., the RSSI) of the wired or wireless signals sent between the first extender AP  440  and the second extender AP  650  to be set accordingly. 
     In step  1195 , the signal strength or power of the wired or wireless signals sent between the root AP  430  and the first extender AP  440  simulates and/or reproduces the physical distance and/or one or more physical obstructions (e.g., the effective distance) between the root AP  230  and the first extender AP  231  in the field test environment  220 . The signal strength or power of the wired or wireless signals sent between the root AP  430  and the second extender AP  650  simulates and/or reproduces the physical distance and/or one or more physical obstructions between the root AP  230  and the second extender AP  232  in the field test environment  220 . The signal strength or power of the wired or wireless signals sent between the first extender AP  440  and the second extender AP  650  simulates and/or reproduces the physical distance and/or one or more physical obstructions between the first extender AP  231  and the second extender AP  232  in the field test environment  220 . Thus, the signal strength or power of the wired or wireless signals sent between each mesh network node  430 ,  440 ,  650  reproduces the configuration of the mesh network nodes  230 - 232  in the field test environment  220 . 
     The signal strength of the wired or wireless signals transmitted between the root AP  430  and the first extender AP  440 , between the root AP  430  and the second extender AP  650 , and between the first and second extender APs  440 ,  650  can reproduce, from the perspective of the root AP  230 , the effective distance between the root AP  230  and the first extender AP  231  and between the root AP  230  and the second extender AP  232 , which allows the field-to-lab testing system  60  to reproduce the same wireless mesh configuration as in the field test environment  220 . 
     The invention should not be considered limited to the particular embodiments described above. Various modifications, equivalent processes, as well as numerous structures to which the invention may be applicable, will be readily apparent to those skilled in the art to which the invention is directed upon review of this disclosure. The above-described embodiments may be implemented in numerous ways. One or more aspects and embodiments involving the performance of processes or methods may utilize program instructions executable by a device (e.g., a computer, a processor, or other device) to perform, or control performance of, the processes or methods. 
     In this respect, various inventive concepts may be embodied as a non-transitory computer readable storage medium (or multiple non-transitory computer readable storage media) (e.g., a computer memory of any suitable type including transitory or non-transitory digital storage units, circuit configurations in Field Programmable Gate Arrays or other semiconductor devices, or other tangible computer storage medium) encoded with one or more programs that, when executed on one or more computers or other processors, perform methods that implement one or more of the various embodiments described above. When implemented in software (e.g., as an app), the software code may be executed on any suitable processor or collection of processors, whether provided in a single computer or distributed among multiple computers. 
     Further, it should be appreciated that a computer may be embodied in any of a number of forms, such as a rack-mounted computer, a desktop computer, a laptop computer, or a tablet computer, as non-limiting examples. Additionally, a computer may be embedded in a device not generally regarded as a computer but with suitable processing capabilities, including a Personal Digital Assistant (PDA), a smartphone or any other suitable portable or fixed electronic device. 
     Also, a computer may have one or more communication devices, which may be used to interconnect the computer to one or more other devices and/or systems, such as, for example, one or more networks in any suitable form, including a local area network or a wide area network, such as an enterprise network, and intelligent network (IN) or the Internet. Such networks may be based on any suitable technology and may operate according to any suitable protocol and may include wireless networks or wired networks. 
     Also, a computer may have one or more input devices and/or one or more output devices. These devices can be used, among other things, to present a user interface. Examples of output devices that may be used to provide a user interface include printers or display screens for visual presentation of output and speakers or other sound generating devices for audible presentation of output. Examples of input devices that may be used for a user interface include keyboards, and pointing devices, such as mice, touch pads, and digitizing tablets. As another example, a computer may receive input information through speech recognition or in other audible formats. 
     The non-transitory computer readable medium or media may be transportable, such that the program or programs stored thereon may be loaded onto one or more different computers or other processors to implement various one or more of the aspects described above. In some embodiments, computer readable media may be non-transitory media. 
     The terms “program,” “app,” and “software” are used herein in a generic sense to refer to any type of computer code or set of computer-executable instructions that may be employed to program a computer or other processor to implement various aspects as described above. Additionally, it should be appreciated that, according to one aspect, one or more computer programs that when executed perform methods of this application need not reside on a single computer or processor, but may be distributed in a modular fashion among a number of different computers or processors to implement various aspects of this application. 
     Computer-executable instructions may be in many forms, such as program modules, executed by one or more computers or other devices. Generally, program modules include routines, programs, objects, components, data structures, etc. that performs particular tasks or implement particular abstract data types. The functionality of the program modules may be combined or distributed as desired in various embodiments. 
     Also, data structures may be stored in computer-readable media in any suitable form. For simplicity of illustration, data structures may be shown to have fields that are related through location in the data structure. Such relationships may likewise be achieved by assigning storage for the fields with locations in a computer-readable medium that convey relationship between the fields. However, any suitable mechanism may be used to establish a relationship between information in fields of a data structure, including through the use of pointers, tags or other mechanisms that establish relationship between data elements. 
     Thus, the disclosure and claims include new and novel improvements to existing methods and technologies, which were not previously known nor implemented to achieve the useful results described above. Users of the method and system will reap tangible benefits from the functions now made possible on account of the specific modifications described herein causing the effects in the system and its outputs to its users. It is expected that significantly improved operations can be achieved upon implementation of the claimed invention, using the technical components recited herein. 
     Also, as described, some aspects may be embodied as one or more methods. The acts performed as part of the method may be ordered in any suitable way. Accordingly, embodiments may be constructed in which acts are performed in an order different than illustrated, which may include performing some acts simultaneously, even though shown as sequential acts in illustrative embodiments.