Patent Publication Number: US-2023155698-A1

Title: Antenna and environmental conditions monitoring for wireless and telecommunications for private, public, and first responders

Description:
INCORPORATION BY REFERENCE OF RELATED APPLICATION 
     Any and all applications, if any, for which a foreign or domestic priority claim is identified in the Application Data Sheet of the present application are hereby incorporated by reference under 37 CFR 1.57. 
     BACKGROUND 
     Firefighters often use radios within buildings to communicate with one another and with other firefighters outside. These radios typically use line-of-sight transceivers that may not adequately reach all areas of the building. In addition, tint coating on building glass in many modern buildings attenuates or blocks radio frequency (RF) signals and thereby prevents reliable communication between firefighters inside and outside the building. Similar problems may be encountered by police and other emergency personnel. 
     To address these problems, a distributed antenna system (DAS) can be installed in a building. A DAS can include a plurality of antennas that are distributed within a building, which can increase radio coverage for first responders like firefighters, policemen, and emergency medical technicians (EMTs). A DAS used by first responders may be referred to as a public safety DAS or Emergency Responder Radio Communication System (ERRCS). Moreover, a DAS can also be employed for other uses, including extending cellular coverage inside a building. Convention centers, for instance, may employ a DAS for large conventions to enable convention goers to maintain cellular connectivity that would be impossible without the DAS, due to the heavy load on limited cellular resources. 
     Referring to  FIG.  1   , an example prior art scenario  100  is shown in which a DAS can be implemented in a building  110 . The building  110  includes a donor antenna  120  on the roof. This donor antenna  120  can communicate with external antennas, such as first responder antennas (not shown) or cellular network radio macro towers  108 . The donor antenna could also be located on another portion of the building other than the roof, such as the side of the building. 
     The donor antenna  120  can receive signals from the first responder antennas or cellular network radio macro towers  108 . These signals can be transmitted along a wire such as a coaxial cable (“coax”) to a bi-directional amplifier (BDA)  130  within the building  110 . The donor antenna  120  can also receive signals to be transmitted from the BDA  130  over the coax. The BDA  130  can act as a repeater that amplifies both received and transmitted signals received from or transmitted to the donor antenna  120 . 
     The BDA  130  can supply and receive signals from additional cabling shown in the building  110 . This cabling communicates with indoor antennas  160  through coax cables  150  or fiberoptic cables (not shown). The cables connect to the indoor antennas  160  and to the BDA  130  via antenna couplers  140 , such as taps or splitters. The indoor antennas  160  can be provided on some or all levels of the building  110 . 
     SUMMARY OF SOME EMBODIMENTS 
     An antenna monitoring system can include a plurality of monitors with electronic circuitry that can be configured to collect monitored data including at least one of a radio frequency (RF) signal data or environmental data. The system can include a plurality of transmitters associated with a plurality of antennas, a transmitter of the plurality of transmitters in communication with a monitor of the plurality of monitors, the plurality of transmitters can be configured to transmit a first plurality of signals to the plurality of antennas, a signal of the first plurality of signals including an antenna identifier for an antenna associated with a transmitter transmitting the signal and monitored data collected by a monitor in communication with the transmitter. The system can include a receiver with electronic circuitry that can be configured to: receive a second plurality of signals from the plurality of antennas, the second plurality of signals transmitted by the plurality of antennas in response to the first plurality of signals being transmitted to the plurality of antennas by the plurality of transmitters, determine from the second plurality of signals a plurality of antenna identifiers and a plurality of monitored data collected by the plurality of monitors, determine that the plurality of antenna identifiers does not include an antenna identifier for a particular antenna of the plurality of antennas, and, in response to the determination that the plurality of antenna identifiers does not include the antenna identifier for the particular antenna, output an indication corresponding to a failure of the particular antenna. 
     The system of the preceding paragraph and/or any of the systems disclosed herein can include any combination of the following features: the transmitters can be configured to be located in proximity to the plurality of antennas, and wherein the antenna identifier is for the antenna located in proximity to the transmitter; each monitor of the plurality of monitors can be associated with one transmitter of the plurality of transmitters; RF signal data can include one or more properties of RF signals received or transmitted by an antenna of the plurality of antennas associated with a monitor of the plurality of monitors; the signal of the first plurality of signals can include a carrier wave at a particular frequency associated with the antenna and monitored data encoded on the carrier wave, the particular frequency corresponding to the antenna identifier; each signal of the first plurality of signals can include a carrier wave at a unique frequency associated with one antenna of the plurality of antennas; electronic circuitry of the receiver can be configured to decode a second signal from the second plurality of signals to determine the monitored data. 
     The system of the preceding paragraph and/or any of the systems disclosed herein can include any combination of the following features: the system can further include a plurality of controllers connecting the plurality of monitors to the plurality of transmitters, the plurality of controllers can be configured to facilitate exchange of data between the plurality of monitors and the plurality of transmitters; the plurality of controllers can be further configured to provide power to the plurality of monitors; a monitor of the plurality of monitors can be supported by a transmitter in communication with the monitor; the transmitter can include a housing enclosing or supporting the monitor; the electronic circuitry of the receiver can be further configured to transmit at least some of the plurality of monitored data to a remote computing system; each transmitter of the plurality of transmitters can be configured to transmit a signal of the first plurality of signals to an associated antenna; the receiver can be configured to be connected to the plurality of antennas via a wired connection, and the electronic circuitry of the receiver can be configured to receive the second plurality of signals from the plurality of antennas via the wired connection; the wired connection can include a first wired connection between the receiver and a coupler and a second wired connection between the coupler and the plurality of antennas. 
     The system of the preceding paragraph and/or any of the systems disclosed herein can include any combination of the following features: at least one transmitter of the plurality of transmitters can be configured to be attached to an associated antenna of the plurality of antennas; each transmitter of the plurality of transmitters can be configured to be placed within receiving range of one antenna of the plurality of antennas but not any other antenna; the electronic circuitry of the receiver can be further configured to output the indication to at least one of a display, a fire alarm control unit, an annunciator panel, or a remote computing system; the system can be configured to monitor at least one of cellular communications network, emergency communications network, or public safety network; the system can further include the plurality of antennas. 
     An antenna monitoring system can include electronic circuitry that can be configured to receive a first plurality of signals from a plurality of antennas, the first plurality of signals transmitted by the plurality of antennas in response to a second plurality of signals being transmitted to the plurality of antennas by a plurality of transmitters associated with the plurality of antennas. The electronic circuitry can be configured to determine from the first plurality of signals a plurality of antenna identifiers and a plurality of monitored data collected by a plurality of monitors in communication with the plurality of transmitters. The electronic circuitry can be configured to determine that the plurality of antenna identifiers does not include an antenna identifier for a particular antenna of the plurality of antennas. The electronic circuitry can be configured to, in response to the determination that the plurality of antenna identifiers does not include the antenna identifier for the particular antenna, output an indication corresponding to a failure of the particular antenna. 
     The system of the preceding paragraph and/or any of the systems disclosed herein can include any combination of the following features: the plurality of monitored data can include at least one of a radio frequency (RF) signal data or environmental data; RF signal data can include one or more properties of RF signals received or transmitted by an antenna of the plurality of antennas associated with a monitor of the plurality of monitors; the transmitters can be configured to be located in proximity to the plurality of antennas, and wherein an antenna identifier is for an antenna located in proximity to a transmitter; each monitor of the plurality of monitors can be associated with a transmitter of the plurality of transmitters; a signal of the second plurality of signals can include a carrier wave at a particular frequency corresponding to an antenna identifier and monitored data encoded on the carrier wave; each of signal of the second plurality of signals can include a carrier wave at a unique frequency associated with one antenna identifier of the plurality of antenna identifiers; the electronic circuitry can be configured to decode a first signal from the first plurality of signals to determine the monitored data. 
     The system of the preceding paragraph and/or any of the systems disclosed herein can include any combination of the following features: the electronic circuitry can be further configured to transmit at least some of the plurality of monitored data to a remote computing system; the electronic circuitry can be configured to receive the first plurality of signals from the plurality of antennas via a wired connection; the wired connection can include a first wired connection between the electronic circuitry and a coupler and a second wired connection between the coupler and the plurality of antennas; the electronic circuitry can be further configured to output the indication to at least one of a display, a fire alarm control unit, an annunciator panel, or a remote computing system; the system can be configured to monitor at least one of cellular communications network, emergency communications network, or public safety network. 
     An antenna monitoring method can include collecting a plurality of monitored data including at least one of a radio frequency (RF) signal data or environmental data. The method can include transmitting a first plurality of signals to a plurality of antennas, a signal of the first plurality of signals including an antenna identifier for an antenna of the plurality of antennas and monitored data of the plurality of monitored data. The method can include receiving a second plurality of signals from the plurality of antennas, the second plurality of signals transmitted by the plurality of antennas in response to the first plurality of signals being transmitted to the plurality of antennas. The method can include determining from the second plurality of signals a plurality of antenna identifiers and a plurality of monitored data. The method can include determining that the plurality of antenna identifiers does not include an antenna identifier for a particular antenna of the plurality of antennas. The method can include, in response to determining that the plurality of antenna identifiers does not include the antenna identifier for the particular antenna, outputting an indication corresponding to a failure of the particular antenna. 
     The method of the preceding paragraph and/or any of the methods disclosed herein can include any combination of the following features: RF signal data can include one or more properties of RF signals received or transmitted by an antenna of the plurality of antennas; a signal of the second plurality of signals can include a carrier wave at a particular frequency for the particular antenna and monitored data encoded on the carrier wave, the particular frequency corresponding to the antenna identifier for the particular antenna; each signal of the second plurality of signals can include a carrier wave at a unique frequency associated with one antenna of the plurality of antennas; determining from the second plurality of signals the plurality of antenna identifiers and the plurality of monitored data can include decoding a second signal from the second plurality of signals to determine the monitored data; the method can further include transmitting at least some of the plurality of monitored data to a remote computing system; receiving the second plurality of signals can include receiving the second plurality of signals via a wired connection; outputting the indication can include outputting the indication to at least one of a display, a fire alarm control unit, an annunciator panel, or a remote computing system. 
     An antenna monitoring method can include, under control of electronic circuitry, receiving a first plurality of signals from a plurality of antennas, the first plurality of signals transmitted by the plurality of antennas in response to a second plurality of signals being transmitted to the plurality of antennas by a plurality of transmitters associated with the plurality of antennas. The method can include, under control of electronic circuitry, determining from the first plurality of signals a plurality of antenna identifiers and a plurality of monitored data collected by a plurality of monitors in communication with the plurality of transmitters. The method can include, under control of electronic circuitry, determining that the plurality of antenna identifiers does not include an antenna identifier for a particular antenna of the plurality of antennas. The method can include, under control of electronic circuitry, in response to determining that the plurality of antenna identifiers does not include the antenna identifier for the particular antenna, outputting an indication corresponding to a failure of the particular antenna. 
     The method of the preceding paragraph and/or any of the methods disclosed herein can include any combination of the following features: plurality of monitored data can include at least one of a radio frequency (RF) signal data or environmental data; RF signal data can include one or more properties of RF signals received or transmitted by an antenna of the plurality of antennas associated with a monitor of the plurality of monitors; the transmitters can be configured to be located in proximity to the plurality of antennas, and wherein an antenna identifier is for an antenna located in proximity to a transmitter; each monitor of the plurality of monitors can be associated with a transmitter of the plurality of transmitters; a signal of the second plurality of signals can include a carrier wave at a particular frequency corresponding to an antenna identifier and monitored data encoded on the carrier wave; each of signal of the second plurality of signals can include a carrier wave at a unique frequency associated with one antenna identifier of the plurality of antenna identifiers; determining from the first plurality of signals the plurality of antenna identifiers and the plurality of monitored data can include decoding a first signal from the first plurality of signals to determine the monitored data; the method can further include transmitting at least some of the plurality of monitored data to a remote computing system; receiving the first plurality of signals can include receiving the first plurality of signals via a wired connection; outputting the indication can include outputting the indication to at least one of a display, a fire alarm control unit, an annunciator panel, or a remote computing system. 
     For purposes of summarizing the disclosure, certain aspects, advantages and novel features of some embodiments are described herein. It is to be understood that not necessarily all such advantages can be achieved in accordance with any particular embodiment disclosed herein. Thus, the embodiments disclosed herein can be embodied or carried out in a manner that achieves or optimizes one advantage or group of advantages as taught herein without necessarily achieving other advantages as may be taught or suggested herein. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The following drawings and the associated descriptions are provided to illustrate embodiments of the present disclosure and do not limit the scope of the claims. 
         FIG.  1    depicts an example prior art scenario in which a DAS can be implemented in a building. 
         FIG.  2    depicts an example DAS that can monitor antenna functionality. 
         FIG.  3    depicts an example antenna and transmitter installation. 
         FIG.  4    depicts example views of the transmitter of  FIG.  3   . 
         FIG.  5    depicts an example head end of a DAS. 
         FIG.  6    depicts an example of a front portion of a receiver. 
         FIG.  7    depicts an example panel of a fire alarm control unit. 
         FIG.  8    depicts an example annunciator panel. 
         FIG.  9    depicts an example antenna fault detection process. 
         FIG.  10    (split across  FIGS.  10 A and  10 B ) depicts a portion of an example DAS installation in an actual building. 
         FIG.  11    depicts another example DAS that can monitor antenna functionality. 
         FIG.  12    depicts an example antenna monitor. 
         FIG.  13    depicts example monitoring system. 
         FIG.  14    depicts another example DAS. 
     
    
    
     While the foregoing “Brief Description of the Drawings” references generally various embodiments of the disclosure, such embodiments are not mutually exclusive. Rather, a myriad of combinations of some or all of such embodiments may be implemented. 
     DETAILED DESCRIPTION 
     Overview 
     One problem with a DAS such as shown in  FIG.  1    (described above) is that in some buildings, numerous antennas may be distributed throughout the building, such as 50, 100, or more antennas. Some antennas may fail from time to time and stop transmitting or receiving signals. Antenna failure can be due to any of a variety of reasons, including, for example, due to the failure of any component of the antenna or the cabling connecting to the antenna (including from rodent damage). If an antenna failure is undetected, then a first responder may not be able to transmit or receive using that antenna in an emergency. Thus, undetected antenna failure can lead to life-threatening situations for first responders and the people they are attempting to save. Similarly, in the cellular context, it can be desirable to provide users with as much coverage as possible to avoid user complaints and frustration from not being able to access a cellular network and associated data. Not only that, but reduced cellular coverage can limit access to emergency 911 services for cellular users. Thus, antenna failure may inconvenience multiple users. 
     The National Fire Protection Association (NFPA) has released a standard, NFPA 1221 (2016) and NFPA 1221 (2019), each of which is hereby incorporated by reference in its entirety, and which address the installation, maintenance, and use of emergency services communications systems. NFPA 1221 specifies that “[t]ests and inspections shall be made” of communications equipment. NFPA 1221 § 11.1.1. However, testing and monitoring antennas can be difficult because it can be very time consuming to manually check the health status of dozens or hundreds of antennas in a large building. Further, DAS installation companies typically install DAS systems in numerous different venues and thus may not have sufficient employee resources to check antennas frequently. It may be that maintenance personnel may not visit a site for several months or even a few years, and thus a broken antenna may go undetected for a long period of time, cutting the signal off in the area of that antenna. 
     To attempt to address these problems, this disclosure describes example antenna monitoring systems and methods that can include, among other things, a transmitter for each of the antennas in a DAS. The transmitter can transmit a signal that includes antenna identification (or antenna identifier) via antenna it is in proximity to for detection by a receiver. For example, the transmitter can transmit data on a certain frequency or channel corresponding to the antenna it is close to, so that the various transmitters in the DAS each transmit on the same or on different frequencies. These frequencies can be detected by the receiver and can be processed to determine whether a signal at any frequency or channel expected to be received is missing. As another example, the transmitter can transmit a signal with an antenna identifier corresponding to the antenna located in proximity to the transmitter. For instance, antenna identifier can be a unique id (such as, unique id of an RFID tag). Each transmitter can transmit a signal with a different antenna identifier. Transmitted signals can be detected by the receiver and processed to determine whether an antenna identifier for the particular antenna is missing. 
     If any expected antenna identifier is missing (for example, if signal is missing for any frequency or channel), the receiver can infer that the antenna or a component associated with the antenna (such as cabling or a transmitter associated with the antenna) may have failed. The receiver can then output an indication or notification that may be accessed by maintenance personnel and/or emergency personnel to enable them to quickly identify and repair the non-functioning antenna or component. Instead of or in addition to looking for missing signals, the receiver can also detect antennas that are supplying very low signals (for example, below a threshold), which may also constitute a failure of the antenna or component. 
     Example DAS that Monitors Antenna Functionality 
     Turning to  FIG.  2   , an example DAS  200  is shown that can implement some or all of the features just described. The DAS  200  is shown implemented in a building  210 . The DAS  200  can be implemented in any building or venue, including office buildings, hospitals, stadiums, and even outdoors (such as in outdoor malls), and the like, without limitation. The DAS  200  can include antenna monitoring functionality that can detect when an antenna or related component is no longer functioning properly, thereby enabling troubleshooting of the faulty antenna or component and thereby bringing reliable service back online quickly. 
     In this example, the DAS  200  includes a donor antenna  202  in communication with a bi-directional amplifier (BDA)  220 . The BDA  220  is shown in communication with a coupler  222 , which may be a tap, splitter, or the like. The coupler  222  is in communication with the plurality of antennas  250  and a head end  270 . Each of the antennas  250  can be indoor antennas like the ones described above with respect to  FIG.  1   . The antennas  250  can also be outdoor antennas (for example, in an outdoor mall). Three antennas  250  are shown on each of three floors; floor  1 , floor  2 , and floor N. An ellipsis between floor  2  and floor N indicate that any number of floors may be used in the DAS  200 . Further, any number of antennas  250 , from one to several, may be installed on any given floor in a building  210 . The antennas  250  need not be installed on every floor. While the antennas  250  are described as being located on floors, any of the antennas  250  can be installed in any location, which may or may not be a floor of a structure. 
     In proximity with each antenna  250  is a transmitter  260 . Each of the transmitters  260  can include hardware and optionally software that transmits antenna identification, which can be a signal (such as a carrier wave or any other suitable signal) at a specific frequency. In some cases, the transmitters  260  may operate at a different frequency or channel for each antenna  250 . As a result, each antenna  250  can detect and then transmit a signal at a different frequency, making that antenna&#39;s output (and thus functioning) readily identifiable by frequency, which can satisfy the NFPA code and meet emergency 911 needs. 
     Each antenna  250  may be in proximity with its corresponding transmitter  260 . An antenna  250  and a transmitter  260  “in proximity,” in addition to having its ordinary meaning, can mean, among other things, that the antenna  250  and transmitter  260  can be in contact with or otherwise mechanically attached to each other, or that the antenna  250  and transmitter  260  can be a short distance away from one another (such as within a number of centimeters, within about one meter, or within about two meters), or that the transmitter  260  may be within a receive range of the antenna  250  such that the transmitter  260  can transmit a signal that will be received by the antenna  250  but that will not be received by another antenna  250  within the same building (or that the received signal will be below a threshold at other antennas  250  within the building). Thus, for example, while another antenna  250  in the building may receive a signal from another antenna&#39;s  250  transmitter  260 , that signal may be at a very low level and possibly below a noise floor. A transmitter  260  can be attached to a wall or junction box near its corresponding antenna  260  in some installations. The transmitter  260  may be within about 1 to 2 meters of the antenna  250  in some installations. The transmitter  260  may also be directly behind the antenna  250 . Moreover, the transmitter  260  may be internal to the antenna  250 , such that the antenna  250  may be sold with the transmitter  260  integrated therewith. 
     As described above, the coupler  222  can couple cables, such as coaxial or fiberoptic cables, between the different antennas and the BDA  220 . The coupler  220  can also couple the BDA  220  and the antennas  250  to the head end  270 . The head end  270  can include a plurality of components that may be in an electrical room of the building  210  or in some other location of the building  210  (such as in a basement or electrical closet). The BDA  220  may be part of the head end  270 . The head end  270  can include an attenuator and/or limiter  224 , a receiver  230 , a fire alarm control unit (FACU)  240 , and an annunciator panel  244 . Fewer than all of the components shown may be provided in other implementations. 
     The attenuator/limiter  224  can attenuate and/or limit incoming signal from the coupler  222  to avoid sending too strong of a signal to the receiver  230 , which might damage the receiver  230 . The receiver  230  can include a processor, memory, and a display. The receiver  230  can receive signals from the antennas  250  through the coupler  220  and the attenuator/limiter  224 . The receiver  230  can analyze the signals using the processor to determine whether any antenna identification is missing. For example, the receiver  230  can determine whether any of the antennas  250  are not receiving on a specific frequency transmitted by a transmitter  260 . If the receiver  230  identifies that a signal at a specific frequency is not received, then the receiver  230  can output an indication of a component failure. The component failure can indicate that an antenna  250  corresponding to that frequency has failed or that some other component associated with that antenna  250  has failed (such as a coupler or cable). 
     The receiver  230  can output this component failure indication on a display of the receiver  230 . Further, the receiver  230  can also output the component failure indication to one or more other devices, including the FACU  240  and the annunciator panel  244 . The FACU  240  can control fire alarms in the building and can also include a display that outputs the indication received from the receiver  230 . The FACU  240  can also communicate the component failure indication over a network  208  (which may include the Internet, a local area network, a wide area network, or the like) to a remote monitor  246 . The remote monitor  246  may be a device (such as a computer or annunciator panel) installed in a fire station or other emergency communications facility. A remote monitor  246  may instead or also be located at a provider facility corresponding to a provider of the DAS  200 . 
     The annunciator panel  244  can also receive an indication of a component failure from the receiver  230  and can output the indication of the failure. This indication may be a lamp, LED, or the like that lights up to indicate that a component has failed (but may or may not indicate which component failed). The annunciator panel  244  may provide firefighters or other emergency personnel a quick, at-a-glance view that a component has failed. The annunciator panel  244  can act as a redundant component to the FACU  240  and may be more reliable than the FACU  240  in the event of a fire or other emergency. 
     The DAS  200  can be an active DAS or a passive DAS. An active DAS can include fiberoptic cable instead of coax or in conjunction with coax. A passive DAS typically includes coax cable instead of fiberoptic cable. Fiberoptic cable can enable antennas  250  to be dispersed over a wider range, such as in a larger building, due to less line loss than coaxial cable. As an alternative to fiberoptic cables for large venues, multiple BDAs and receivers may be spread throughout a building, connected by coax, so that each BDA and receiver correspond to a subset of the antennas in the building. The multiple receivers can send their indications to a single head end that includes an FACU and an annunciator panel or the like. Many other configurations are also possible. 
     The receiver  230  can also detect larger-scale failures and report these failures. For instance, if the receiver  230  does not receive expected signals from all antennas  250  on one floor, the receiver  230  can indicate that there may be a problem with a coupler that feeds line to that floor. If the receiver  230  does not receive any expected signals, the receiver  230  may indicate that the coupler  222  or some other major component may have failed. 
     Although the system shown in  FIG.  2    is a DAS, it should be understood that the inventive features described herein are not limited to being implemented in a DAS. Rather, some or all of the features described herein can be implemented in cellular sites, such as radio macro antennas, or in other antenna installations. 
     Turning to  FIG.  3   , an example antenna and transmitter installation  300  is shown. The antenna installation  300  includes an antenna  350 , which is an example of the antenna  250  described above with respect to  FIG.  2   . The antenna installation  300  also includes a transmitter  360 , which is an example of the transmitter  260  described above with respect to  FIG.  2   . The transmitter  360  is shown connected or attached mechanically to the antenna  350  in this example installation  300 . In other configurations, as described above, the transmitter  360  need not be connected directly to the antenna  350 . 
     In some implementations, the transmitter  360  transmits at a power that is sufficient to be detected above the noise floor at the antenna  350  but not so high as to create stray currents in the coax connected to the antenna  350 . For example, the transmitter  360  can transmit at about −15 dBm (decibels relative to one milliwatt). However, in other implementations, the transmitter  360  can transmit in the range of about −20 dBm to about 0 dBm, or in the range of about −25 dBm to about 5 dBm, or in the range of about −30 dBm to about 20 dBm, or in some other range. 
     The transmitter  360  may be battery powered. It can be useful to reduce battery consumption of the transmitter  360  because having a transmitter fail  360  can be nearly as significant a problem as an antenna failing  350  (if a transmitter  360  fails, the receiver  230  may indicate that the antenna  350  has failed). To conserve battery, the transmitter  360  can be configured to transmit at a rate that reduces power consumption. For instance, the transmitter  360  can transmit periodically, such as once every few minutes, once every hour, once every day, once every 48 hours, or at some other interval. Current transmitters may have a battery life of about two years. In present and future antenna implementations, including 5G wireless, which may use millimeter wave frequencies, the transmitter  360  can be a millimeter wave transmitter that consumes so little power as to be able to have a battery life of ten years or more. In general, any of the features described herein can be used in any cellular installation, such as a 5G wireless installation or in installations supporting subsequent wireless standards. 
     The transmitter  360  can include or be connected to a photovoltaic power source (such as, a solar panel). For example, the transmitter  360  can include or be connected to one or more solar panels configured to store energy in one or more energy storage elements, such as one or more capacitors. Photovoltaic power may be utilized for cellular sites as cellular antennas are typically placed outdoors. 
     The transmitter  360  can transmit on any of a variety of frequencies. For instance, the transmitter  360  can transmit on the 900 MHz band (for example, between about 902 MHz and about 928 MHz, or some other range), and the antenna  350  may communicate with public safety radios or cellular radios on the 800 MHz band. However, other frequency bands may be used without limitation, such as any band in the range of 0 Hz to 20 GHz or higher. For example, the transmitter  360  may transmit on frequencies other than the 900 MHz band to avoid interfering with hospital paging systems (if the transmitter  360  is installed in a hospital or other medical facility). More generally, the transmitter  360  can transmit at frequencies in the range of about 0 Hz to 20 GHz or higher. The transmitter  360  may operate on licensed or unlicensed frequencies. 
     As disclosed herein, any of the transmitters can include hardware, such as electronic circuitry (which can include one or more processors). Transmitter hardware can include a chipset configured to transmit any of the signals disclosed herein. Any of the antennas disclosed herein can include a chipset configured to receive any of the signals from the transmitter. The transmitter chipset can be configured to implement monitoring functionality as described herein. For example, monitoring functionality can be used to detect and transmit receiving or transmission power of the antenna located in proximity of the transmitter, environmental data, or the like. Such detection and transmission can be performed in real time or substantially in real time. In some cases, monitoring could be used for focused beam technology for 5G by carriers to improve and monitor service, which can facilitate ensuring optimal functionality, low (or zero) latency, or the like. 
     Turning to  FIG.  4   , two example views of the transmitter  360  are shown, including a front view  360   a  and a rear view  360   b . This transmitter  360  is an example transmitter model number VL965-B7 available from Systems Technologies, Inc. The transmitter  360  can be an off-the-shelf transmitter used typically in nurse call functions in hospitals. These types of transmitters may be good transmitters for this application because they can be battery-operated and can operate in a frequency band that is different from the main operating frequency band of the antenna  250  or  350 , so as to reduce interference between the two frequency bands. 
     Turning to  FIG.  5   , an example head end  500  is shown with a BDA  520  that is connected via coax cable to a coupler  522 , attenuator  524 , limiter  525 , and receiver  530 . The coupler  522  is connected to a receiver  530  via cabling, an attenuator  524 , and a limiter  525 . The BDA  520  is an example of the BDA  220  of  FIG.  2   . Likewise, the coupler  522 , the attenuator  524 , limiter  525 , and receiver  530  are examples of their respective counterparts from  FIG.  2   . 
     Example component types are listed in  FIG.  5   , which may be varied in various embodiments. The coupler  522 , for instance, can be a tap that provides unequal signal distribution at the different outputs of the tap to enable an antenna that is farther from the receiver to receive an appropriate amount of signal. Due to signal loss over longer distances, the output of the tap to a more distant antenna may be greater than to a closer antenna. The cable from the upper connection of the coupler  522  can be connected to the antennas  250  through other couplers (see, e.g.,  FIG.  10   ). For simplicity, a connection to a donor antenna from the BDA  520  is not shown. 
     The attenuator  524  can reduce the signal received from the coupler  522  to avoid sending a signal of too high a level to the receiver  530 . The limiter  525  can limit the level of the signal to a certain dBm value to attempt to prevent transient spikes from damaging the receiver  530 . Example cable lengths are shown as well as example dBm values for inputs and outputs of the different components. These values may be varied in other embodiments. 
     Turning to  FIG.  6   , an example of a front portion of a receiver  630  is shown. The receiver  630  shown is a model VL400-B7 available from Systems Technologies, Inc. Other types of receivers may be used. 
     The front portion of the receiver  630  is zoomed in to show a close-up of a display  632  of the receiver. The display  632  includes the text “Ant-3 Floor2 FLT,” which can indicate that antenna number  3  on the second floor has a fault. A map of the building may be provided near the receiver  630  for first responders to find where antenna  3 , as well as other antennas, are located. 
     Turning to  FIG.  7   , an example panel of an FACU  740  is shown. The FACU  740  includes a display  742  which also includes information that can be received from the receiver described above, and which includes text that indicates that an ERRCS  1  component failed  219 . The ERRCS component refers to an emergency responder radio communications system component, such as an antenna, and the number  219  can refer to a region of the building. The information on the display of the FACU  740  can be transmitted to the remote monitor  246  at the fire department or other emergency communications center, as described above. 
     Turning to  FIG.  8   , an example annunciator panel  844  is shown corresponding to the annunciator panel  244  of  FIG.  2   . The annunciator panel  844  includes lamp areas  850  that are labeled. If a lamp is lit, the condition specified by text  850  corresponding to the lamp has occurred. Thus, in the depicted example, a lamp has indicated that there is a component failure. 
     Turning to  FIG.  9   , an example antenna fault detection process  900  is shown. The antenna fault detection process  900  can be implemented by any of the receivers described herein. For example, a hardware processor of a receiver may implement the process  900  shown to detect a fault with an antenna or another component corresponding to that antenna. 
     At block  902 , the receiver monitors a plurality of signals from antennas in a distributed antenna system. At decision block  904 , if any expected antenna identification is not received (for example, is signals are not received from any expected frequencies), then the receiver at block  906  identifies an antenna corresponding to the missing antenna identification (for example, missing signal frequency) and outputs an indication of a component failure corresponding to the identified antenna at block  908 . Otherwise, from decision block  904 , if all expected antenna identification have been received (for example, signals are received from all expected frequencies), then the process  900  loops back to block  902  where the receiver continues to monitor a plurality of signals from the antennas in the DAS. 
     In another embodiment, instead of determining whether no signals are received, the process  900  can determine whether an expected signal is below a threshold in signal level. An abnormally low signal level can indicate a problem with an antenna or related component, even if the signal is in fact received. If the signal level corresponding to a particular frequency is too low, the receiver can output an indication of a fault with the antenna or a component corresponding with that antenna. 
     Turning to  FIG.  10   , which is shown as  FIGS.  10 A and  10 B  split over two pages, an example DAS  1000  is shown as a portion of a DAS in a building. The DAS  1000  includes several components similar to those described above, including a donor antenna  1002 , couplers  1022 , antennas  1050 , transmitters  1060 , a BDA  1020 , an attenuator  1024 , and a receiver  1030 . 
     The DAS  1000  shown can represent a full DAS in a building or one subset of a DAS in an actual building. For instance, the DAS  1000  can be part of a larger DAS separated into two or more separate DAS&#39;s that cover different areas of the building. One area serviced by one subset of the DAS (or sub-DAS) can include, for example, the stairwells, while another area serviced by another sub-DAS can include the remaining portions of the floors. Covering the stairwells with a separate sub-DAS can provide backup functionality for first responders in the stairwell, which can be an important point of access for first responders to a building. When multiple sub-DASs are used as part of a DAS, each sub-DAS can have each of the components shown or some subset or superset thereof, including a separate donor antenna. 
       FIG.  11    illustrates an example DAS  1100 . Similarly to the DAS  200  of  FIG.  2   , a plurality of antennas  1150  and a head end  1170  are shown. Any of the antennas  1150  can have one or more features of any of the antennas  250  and/or any other antennas described herein. The head end  1170  can be have one or more features of the head end  270  and/or any other head end described herein. The antennas  1150  can be coupled by one or more cables or wires to a BDA of the head end  1170 , as described herein. 
     An antenna monitor  1180  can monitor one or more signals emitted by a corresponding antenna  1150 . The antenna monitor  1180  can include electronic circuitry configured to perform such monitoring. The antenna monitor  1180  can be placed in proximity to the corresponding antenna  1150 , as described herein. As shown in  FIG.  12   , the antenna monitor  1180  can include a signal detector  1286  configured to detect RF signals emitted by the corresponding antenna  1150 . The signal detector  1286  can be connected to the corresponding antenna  1150  via a wired connection. For example, the signal detector  1286  can be connected to an output terminal  1282  and a ground terminal  1284  of the corresponding antenna  1150 . In some implementations, the signal detector can wirelessly detect RF signals emitted by the corresponding antenna  1150  without the wired connection. The signal detector  1286  can perform such detection over a time period. The signal detector  1286  can output a signal  1288  of whether any RF signals emitted by the corresponding antenna  1150  have been detected. 
     An indicator  1185  can receive a signal from a corresponding antenna monitor  1180 . For example, as illustrated in  FIG.  12   , the signal  1288  can be output from the signal detector  1286  to the indicator  1185 . The indicator  1185  can provide an indication of whether any RF signals emitted by the corresponding antenna  1150  have been detected. The indicator can include electronic circuitry configured to provide such indication. If the corresponding antenna  1150  has not emitted any RF signals, the indicator  1185  can provide an indication of a component failure of the corresponding antenna  1150 . The indication can, for example, include turning on a visual indicator, such as an LED light. The indicator  1185  can output the component failure indication to one or more other devices, such as a FACU and an annunciator panel of the head end  1170 , as described herein. As illustrated in  FIG.  12   , the indicators  1185  associated with the antennas  1150  can be connected to such one or more devices by one or more cables or wires. The component failure indication can include any of the indications described herein, such as visual, audible, communication to a remote computing device, or the like. 
     The indicator  1185  can be positioned proximate to the corresponding monitor  1180 . The indicator  1185  and the corresponding monitor  1150  can be enclosed in the same housing or in different housings. 
     Additional Monitoring Functionality 
     Any of the transmitters can additionally or alternatively monitor one or more additional parameters or conditions (sometimes referred to as monitored data). Such conditions can include one or more of RF signal strength (for example, associated with RF signals received or transmitted by the antenna), environmental parameters or data, or the like. Data relating to the one or more additional conditions can be transmitted to a receiver (or multiple receivers) as disclosed herein. 
       FIG.  13    illustrates a monitoring system  1300 . Antenna  250  and transmitter  260 , which are described herein, are shown. Also shown is a monitor  1320  that can include electronic circuitry configured to monitor, among other things, environmental data, RF data, or the like. Monitor  1320  can be associated with the transmitter  260 . For instance, each transmitter  260  can be associated with a monitor  1320 . Monitor  1320  can be positioned in proximity of the transmitter  260 , as described herein. 
     Environmental data can include one or more of temperature, atmospheric or barometric pressure, wind speed, wind direction, vibration (or motion), precipitation, humidity, UV levels, or the like. One or more sensors can be connected to or incorporated into the electronic circuitry of the monitor  1320  to facilitate the monitoring. For monitoring environmental data, the sensors can include one or more of temperature sensors, barometric pressure sensors, anemometers, moisture sensors, or the like. 
     Monitor(s)  1320  (and associated transmitter(s)  260 ) can be deployed, for instance, at weather or observation stations, which can be designed to forecast weather conditions (such as tornadoes hurricanes, earthquakes, avalanches, heavy rains, heat waves, cold temperatures, or the like). Operation of such advanced weather warning systems can be improved. As an example, existing tornado monitoring systems include observation stations that are spaced far apart from each other (such as, several miles apart) and communicate with one or more weather station over telephone landlines. Existing tornado monitoring systems can be ineffective and unreliable. Deployment of one or more monitors  1320  (and associated transmitters  260 ) at tornado monitoring observation stations can improve reliability and efficiency, among others. 
     RF data can include information related to one or more properties of electromagnetic waves, such as signal to noise ratio (SNR or SINR), received signal strength indicator (RSSI), reference signal receive power (RSRP), reference signal received quality (RSRQ), voltage standing wave ratio (VSWR), physical cell id (PCI)/pilot number (PN), electromagnetic energy (EME), electromagnetic radiation (EMR), or the like. Monitor  1320  can measure magnitude of a detected RF signal versus frequency within a frequency range. Monitor  1320  can include an antenna and receiver or transceiver circuitry for detecting RF signals. RF data collected by the monitor  1320  can be used to determine performance of antenna  250  associated with the transmitter  260  and the monitor  1320 . For instance, monitored RF data can be provided to a network carrier or any other third party to facilitate monitoring of a network (such as a cellular network), analyze performance of the network, or the like. RF data can be used to determine one or more key performance indicators (KPIs) of one or more antennas  250  or the DAS in order to, for instance, optimize performance, tune the network, or the like. For example, one or more KPIs can include reception or transmission signal strength of an antenna, quality of the transmitted or received signal, or the like. Monitor  1320  can include any of the functionality of the antenna monitor  1180  as described herein. 
     Transmitter  260  can receive data obtained by the monitor  1320  via a wired or wireless connection. Transmitter  260  can transmit the data to the receiver via the antenna  250 , as described herein. Data obtained by the monitor  1320  can be transmitted by the transmitter  260  in addition to or in place of antenna identifier. For example, data obtained by the monitor  1320  can be encoded together with antenna identifier and the encoded signal can be transmitted. For instance, as described herein, antenna identifier can be a signal transmitted at specific frequency. In such case, data obtained by the monitor  1320  can be transmitted on the specific frequency associated with the transmitter  260 , such as encoded on a carrier signal or wave being transmitted at the specific frequency. Encoding on the carrier wave can be performed using encoding or modulation, such as amplitude modulation, frequency modulation, phase modulation, or the like. In some cases, the transmitter  260  can be programmed or otherwise configured (for example, by adjusting or programming the chipset) so that transmitted signal is a carrier wave allowing information of all types to be transmitted through the antenna back to the receiver where it can be collected and transmitted back to a remote computing device for monitoring, analytics, or the like. 
     In some cases, a controller  1310  can be interposed between the transmitter  260  and the monitor  1320 . Controller  1310  can, among other things, provide power to the monitor  1320 , communicate data between the transmitter  260  and monitor  1320 , or the like. Transmitter  260  can provide power to the controller  1310 . Controller  1310  can be connected to the transmitter  260  or monitor  1320  via a wired or wireless connection. For instance, the monitor  1320  can include a USB interface (or the like) over which power can be provided from the controller  1310  to the monitor  1320  and data can be exchanged between the controller  1310  and the monitor  1320 . In some instances, controller  1310  can include an Arduino device (or another similar device). The controller  1310  can include a USB interface (or the like) for connecting to the transmitter  260 . In some cases, monitor  1320  can include one or more of a USB spectrum analyzer available from Triarchy Technology (or another similar device) or USB weather data logger available from Davis Instruments (or another similar device). In some cases, functionality of the monitor  1320  can be incorporated into the transmitter  260  and the controller  1310  is not used. 
     One or more of the monitor  1320  or controller  1310  can be supported by the transmitter  260 , such as attached to housing of the transmitter or enclosed by the housing. Monitoring and transmission of monitored data can be performed in real time or substantially in real time. Monitoring and transmission of monitored data can be performed periodically, for example, at the time the transmitter  260  transmits the antenna identifier. 
     In some cases, one or more transmitters  260  can transmit monitored data directly to the receiver (or a remote computing system) without using corresponding one or more antennas  250 . For example, the receiver (or the remote computing system) can poll one or more transmitters  260  or one or more transmitters  260  can transmit monitored data to the receiver without having been polled. Monitored data can be transmitted to the receiver (or the remote computing system) via a wired or wireless connection (such as Bluetooth, Zigbee, WiFi, Z-Wave, or the like). 
       FIG.  14    illustrates an example DAS  1400 , which can be similar to any DAS described herein, such as DAS  200  of  FIG.  2   . The DAS  1400  is shown implemented at site  1410 , which can be any indoor or outdoor location, as described herein. The DAS  1400  can be implemented in any building or venue whether indoor or outdoor. As illustrated, the DAS  1400  can include a plurality of transmitters  260 , antennas  250 , and a head end  1470 . The head end  1470  can be have one or more features of the head end  270  and/or any other head end described herein. The antennas  250  can be coupled by one or more cables or wires to a BDA  220  of the head end  1470 , as described herein. As described herein, a plurality of monitors  1320  can be positioned in proximity to the transmitters  260  as shown in  FIG.  14   . 
     Data received by a receiver  1430  of the head end  1470  can include antenna identification and monitored data, as described herein. The receiver  1430  can include a processor and memory. The receiver  1430  can determine whether any of antenna identification is missing, as described herein. For example, the receiver  1430  can determine that identification associated with a particular antenna is missing in response to determining that a signal at a particular frequency corresponding to the particular antenna has not been received. Additionally or alternatively, the receiver  1430  can determine or identify monitored data. For example, the receiver  1430  can decode monitored data, such as, decode monitored data encoded on a carrier wave transmitted at a particular frequency. Monitored data can be one or more of processed, stored in memory, transmitted to a remote computing device(s) (not shown), or the like. Transmission of monitored data can be performed using a network, such as the network  208 . One or more remote computing devices (for example, a network carrier) can perform monitoring, analytics, or the like. 
     In some cases, one or more of the transmitters  260  (or monitors  1320 ) can be configured to monitor and record proximity of a person to one or more antennas  250 , transmitters  260 , or monitors  1320 . For example, Bluetooth protocol (or similar) can be used to detect presence of a computing device of the person (such as mobile computing device) in proximity to the one or more transmitters  260  (or monitors  1320 ). This can be used for determining locations visited by the person (and visiting times), which can assist with contact tracing or the like for limiting the spread of an infectious disease (such as coronavirus). 
     In some cases, one or more of the transmitters  260  (or monitors  1320 ) can be configured to partially or completely block any of the signals received or transmitted by any of the antennas  250 . For example, one or more of the transmitters  260  (or monitors  1320 ) can generate an RF signal that may interfere with any of the signals received or transmitted by any of the antennas  250 . This functionality may be used to block transmission of certain data from being transmitted by the DAS. 
     Additional Embodiments 
     The features of using a transmitter to monitor an antenna can be implemented in contexts other than a DAS. For instance, in a cellular network, a transmitter may be placed next to any antenna to monitor that antenna. Signals received from the transmitter by the antenna may be provided to a processor, either at the antenna or remote from the antenna. The processor can determine whether a signal is received or whether a signal of sufficiently high level is received. If not, the processor can output an indication that the antenna or an associated component in communication with the antenna (such as a coupler or cable) may not be functioning properly. More generally, a transmitter can be placed in proximity with any antenna to monitor the functionality of that antenna, including antennas used in radar or other applications. 
     The transmitter may also include software or firmware installed thereon, which may have a variety of possible different functions. The software or firmware may have a networking functionality (such as a network interface implementing the TCP/IP stack) that enables remote communication with the transmitter. Each transmitter may be wired or wirelessly connected to a remote system. A remote server, for instance, can provide administrator devices with network access to the transmitters. The remote server may deliver a web page or other graphical user interface to an administrative device, which user interface can enable an administrative device to remotely monitor a health of a transmitter ( 260 ) and/or its associated antenna ( 250 ). Remotely monitoring a transmitter and/or antenna may reduce the need for maintenance personnel to personally inspect transmitters and antennas. 
     Each transmitter may have a dynamic or static IP address, which can enable network communication with the transmitter. The user interface may indicate whether a transmitter has frozen or otherwise locked up. The user interface may provide an option for a user to select to restart a transmitter that has frozen or for any other reason. Upon user selection of this option, the remote server can transmit a command to the transmitter to power cycle or otherwise restart operation. In response, a hardware processor in the transmitter can perform a power cycle operation. The user interface may also output that a transmitter/antenna pair is no longer functioning in some way. By providing a remote power cycle option, the user interface may allow a user to determine whether the antenna or the transmitter is failing. If the transmitter/antenna pair continues to appear to not be functioning in the user interface, even after a power cycle, then the antenna or transmitter may have failed. 
     In another example, the receiver is network-enabled, and the remote server can communicate with the receiver to obtain the same information described above (for example, regarding component failures) instead of communicating individually with the transmitters. 
     Any of the transmitters disclosed herein can be powered from a central power supply. One or more wires can connect any of the transmitters to the central power supply. Existing wiring (for example, as shown in  FIG.  2   ) can be used to supply power to any of the transmitters. 
     Any one or more features of the monitoring systems and methods disclosed herein can be applied in the context of monitoring at least a portion of a FirstNet public safety network (“FirstNet network”). FirstNet network is designed to be an interoperable, high-speed broadband network that provides a single interoperable platform for law enforcement, firefighters, paramedics, and other public safety personnel across the United States. FirstNet network is designed to connect radio access networks of each state to a network core. 
     Terminology 
     Conditional language, such as, among others, “can,” “could,” “might,” or “may,” unless specifically stated otherwise, or otherwise understood within the context as used, is generally intended to convey that certain embodiments include, while other embodiments do not include, certain features, elements and/or steps. Thus, such conditional language is not generally intended to imply that features, elements and/or steps are in any way required for one or more embodiments or that one or more embodiments necessarily include logic for deciding, with or without user input or prompting, whether these features, elements and/or steps are included or are to be performed in any particular embodiment. 
     Unless the context clearly requires otherwise, throughout the description and the claims, the words “comprise,” “comprising,” “include,” “including,” “having,” and the like are to be construed in an inclusive sense, as opposed to an exclusive or exhaustive sense; that is to say, in the sense of “including, but not limited to.” As used herein, the terms “connected,” “coupled,” or any variant thereof means any connection or coupling, either direct or indirect, between two or more elements; the coupling or connection between the elements can be physical, logical, or a combination thereof. Additionally, the words “herein,” “above,” “below,” and words of similar import, when used in this application, refer to this application as a whole and not to any particular portions of this application. Where the context permits, words in the above Detailed Description using the singular or plural number may also include the plural or singular number respectively. The word “or” in reference to a list of two or more items, covers all of the following interpretations of the word: any one of the items in the list, all of the items in the list, and any combination of the items in the list. Likewise the term “and/or” in reference to a list of two or more items, covers all of the following interpretations of the word: any one of the items in the list, all of the items in the list, and any combination of the items in the list. 
     Language of degree used herein, such as the terms “approximately,” “about,” “generally,” and “substantially” as used herein represent a value, amount, or characteristic close to the stated value, amount, or characteristic that still performs a desired function or achieves a desired result. For example, the terms “approximately”, “about”, “generally,” and “substantially” may refer to an amount that is within less than 10% of, within less than 5% of, within less than 1% of, within less than 0.1% of, and within less than 0.01% of the stated amount. 
     Depending on the embodiment, certain operations, acts, events, or functions of any of the algorithms described herein can be performed in a different sequence, can be added, merged, or left out altogether (e.g., not all are necessary for the practice of the algorithms). Moreover, in certain embodiments, operations, acts, functions, or events can be performed concurrently, e.g., through multi-threaded processing, interrupt processing, or multiple processors or processor cores or on other parallel architectures, rather than sequentially. 
     These and other changes can be made to the inventions in light of the above Detailed Description. While the above description describes certain examples of the inventions disclosed herein, and describes the best mode contemplated, no matter how detailed the above appears in text, the inventions can be practiced in many ways. Details of the system may vary considerably in its specific implementation, while still being encompassed by the inventions disclosed herein. As noted above, particular terminology used when describing certain features or aspects of the inventions should not be taken to imply that the terminology is being redefined herein to be restricted to any specific characteristics, features, or aspects of the inventions with which that terminology is associated. 
     Any claims intended to be treated under 35 U.S.C. § 112(f) will begin with the words “means for”, but use of the term “for” in any other context is not intended to invoke treatment under 35 U.S.C. § 112(f). Accordingly, the applicant reserves the right to pursue additional claims after filing this application, in either this application or in a continuing application.