Abstract:
Power management techniques in distributed communication systems are disclosed. Related components, systems, and methods are also disclosed. In embodiments disclosed herein, the power available at a remote unit (RU) is measured and compared to the power requirements of the RU. In an exemplary embodiment, voltage and current is measured for two dummy loads at the RU and these values are used to solve for the output voltage of the power supply and the resistance of the wires. From at these values, a maximum power available may be calculated and compared to power requirements of the RU.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of priority under 35 U.S.C. §119 of U.S. Provisional Application Ser. No. 61/884,452 filed on Sep. 30, 2013, the content of which is relied upon and incorporated herein by reference in its entirety. 
    
    
     BACKGROUND 
     The technology of the disclosure relates generally to providing power and more particularly to providing power in remote units (RUs) which may be used in a distributed communication system. 
     Wireless communication is rapidly growing, with ever-increasing demands for high-speed mobile data communication. As an example, so-called “wireless fidelity” or “WiFi” systems and wireless local area networks (WLANs) are being deployed in many different types of areas (e.g., coffee shops, airports, libraries, etc.). Distributed communication systems (one type of which is a distributed antenna system) communicate with wireless devices called “clients,” which must reside within the wireless range or “cell coverage area” to communicate with an access point device. 
     One approach to deploying a distributed antenna system involves the use of radio frequency (RF) antenna coverage areas, also referred to as “antenna coverage areas.” Antenna coverage areas can have a radius in the range from a few meters up to twenty meters as an example. Combining a number of access point devices creates an array of antenna coverage areas. Because each antenna coverage area covers a relatively small area, there are typically only a few users (clients) per antenna coverage area. This allows for minimizing the amount of RF bandwidth shared among the wireless system users. It may be desirable to provide antenna coverage areas in a building or other facility to provide distributed antenna system access to clients within the building or facility. Further, it may be desirable to employ optical fiber to distribute communication signals due to the high bandwidth available to optical fibers. 
     One type of distributed antenna system for creating antenna coverage areas includes distribution of RF communication signals over an electrical conductor medium, such as coaxial cable or twisted pair wiring. Another type of distributed antenna system for creating antenna coverage areas, called “Radio-over-Fiber” or “RoF,” utilizes RF communication signals sent over optical fibers. Both types of systems can include head-end equipment coupled to a plurality of RUs. Each RU may include an antenna and may be referred to as a remote antenna unit or RAU. Each RU provides antenna coverage areas. The RUs can each include RF transceivers coupled to an antenna to transmit RF communication signals wirelessly, wherein the RUs are coupled to the head-end equipment via the communication medium. The RF transceivers in the RUs are transparent to the RF communication signals. The antennas in the RUs also receive RF signals (i.e., electromagnetic radiation) from clients in the antenna coverage area. The RF signals are then sent over the communication medium to the head-end equipment. In optical fiber or RoF distributed antenna systems, the RUs convert incoming optical RF signals from an optical fiber downlink to electrical RF signals via optical-to-electrical (O/E) converters, which are then passed to the RF transceiver. The RUs also convert received electrical RF communication signals from clients via the antennas to optical RF communication signals via electrical-to-optical (E/O) converters. The optical RF signals are then sent over an optical fiber uplink to the head-end equipment. 
     The RUs contain power-consuming components, such as the RF transceiver, to transmit and receive RF communication signals and require power to operate. In the situation of an optical fiber-based distributed antenna system, the RUs may contain O/E and E/O converters that also require power to operate. In some installations, the RU may contain a housing that includes a power supply to provide power to the RUs locally at the RU. The power supply may be configured to be connected to a power source, such as an alternating current (AC) power source, and convert AC power into a direct current (DC) power signal. Alternatively, power may be provided to the RUs from remote power supplies. The remote power supplies may be configured to provide power to multiple RUs. It may be desirable to provide these power supplies in modular units or devices that may be easily inserted or removed from a housing to provide power. Providing modular power distribution modules allows power to more easily be configured as needed for the distributed antenna system. For example, a remotely located power unit may be provided that contains a plurality of ports or slots to allow a plurality of power distribution modules to be inserted therein. The power unit may have ports that allow the power to be provided over an electrical conductor medium to the RUs. Thus, when a power distribution module is inserted in the power unit in a port or slot that corresponds to a given RU, power from the power distribution module is supplied to the RU. 
     In many installations, there will be power connections made to many different RUs. There are occasions when there may be errors in connections made between elements in such installations. Thus, there is a need to verify connections so that system integrity may be ascertained. 
     No admission is made that any reference cited herein constitutes prior art. Applicant expressly reserves the right to challenge the accuracy and pertinency of any cited documents. 
     SUMMARY OF THE DETAILED DESCRIPTION 
     One embodiment of the disclosure relates to a remote unit (RU) for use in a distributed communication system. The RU includes an antenna capable of transmitting into a coverage area. The RU also includes a power port configured to receive a direct current (DC) power signal from a power distribution module through a power medium. The RU also includes an alternating current (AC) filter coupled to the power port configured to filter out AC signals from the DC power signal and provide DC power to the RU. The RU also includes a DC filter coupled to the power port and configured to filter out the DC power signal from AC signals received from the power medium. The RU also includes an AC test signal detection circuit coupled to the DC filter and configured to detect an AC test signal arriving at the power port from the power medium. The RU also includes a slave controller coupled to the AC test signal detection circuit. The slave controller is configured to generate a response for transmission to a master controller on detection of the AC test signal. 
     An additional embodiment of the disclosure relates to a distributed communication system. The distributed communication system includes a plurality of RUs, each RU having one or more antennas capable of transmitting into a coverage area. The distributed communication system also includes a power unit configured to provide power to one or more of the plurality of RUs across one or more power media. The distributed communication system also includes a control system configured to cause an AC test signal to be created at the power unit. The control system is also configured to send the AC test signal via the one or more power media to the one or more RUs. The control system is also configured to receive an acknowledgment signal from the one or more RUs indicating receipt of the AC test signal. 
     An additional embodiment of the disclosure relates to a method of operating a distributed communication system. The method includes coupling an output port of a power unit to a power medium. The method also includes coupling the power medium to a RU capable of transmitting into a coverage area. The method also includes generating an AC test signal at the power unit. The method also includes sending the AC test signal to the RU. The method also includes receiving an acknowledgment signal from the RU. 
     Additional features and advantages will be set forth in the detailed description which follows, and in part will be readily apparent to those skilled in the art from the description or recognized by practicing the embodiments as described in the written description and claims hereof, as well as the appended drawings. 
     The foregoing general description and the detailed description are merely exemplary, and are intended to provide an overview to understand the nature and character of the claims. 
     The accompanying drawings are included to provide a further understanding, and are incorporated in and constitute a part of this specification. The drawings illustrate one or more embodiment(s), and together with the description serve to explain principles and operation of the various embodiments. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic diagram of an exemplary distributed antenna system; 
         FIG. 2A  is a partially schematic cut-away diagram of an exemplary building infrastructure in which the distributed antenna system in  FIG. 1  can be employed; 
         FIG. 2B  is an alternative diagram of the distributed antenna system in  FIG. 2A ; 
         FIG. 3  is a schematic diagram of power provision in a distributed antenna system such as the distributed antenna system of  FIG. 1 ; 
         FIG. 4  is a schematic diagram of a power unit and a remote unit (RU) from  FIG. 3  showing additional details; 
         FIG. 5  is a flow chart of an exemplary connection mapping process used by a distributed communication system such as that shown in  FIGS. 1-4 ; and 
         FIG. 6  is a schematic diagram of a generalized representation of a computer system that can be included in the power distribution modules disclosed herein, wherein the exemplary computer system is adapted to execute instructions from an exemplary computer-readable media. 
     
    
    
     DETAILED DESCRIPTION 
     Various embodiments will be further clarified by the following examples. 
     While the concepts of the present disclosure are applicable to different types of distributed communication systems, an exemplary embodiment is used in a distributed antenna system and this exemplary embodiment is explored herein. Before discussing an exemplary connection mapping system, exemplary distributed antenna systems capable of distributing radio frequency (RF) communication signals to remote units (RUs) are first described with regard to  FIGS. 1-2B . It should be appreciated that in an exemplary embodiment the RUs may contain antennas such that the RU is a remote antenna unit and may be referred to as an RAU. 
     In this regard, the distributed antenna systems in  FIGS. 1-2B  can include power units located remotely from RUs that provide power to the RUs for operation. Embodiments of power mapping systems in a distributed communication systems, including the distributed antenna systems in  FIGS. 1-2B , begin with  FIG. 3 . The distributed antenna systems in  FIGS. 1-2B  discussed below include distribution of radio frequency (RF) communication signals; however, the distributed antenna systems are not limited to distribution of RF communication signals. Also note that while the distributed antenna systems in  FIGS. 1-2B  discussed below include distribution of communication signals over optical fiber, these distributed antenna systems are not limited to distribution over optical fiber. Distribution mediums could also include, but are not limited to, coaxial cable, twisted-pair conductors, wireless transmission and reception, and any combination thereof. Also, any combination can be employed that also involves optical fiber for portions of the distributed antenna system. 
     In this regard,  FIG. 1  is a schematic diagram of an embodiment of a distributed antenna system. In this embodiment, the system is an optical fiber-based distributed antenna system  10 . The distributed antenna system  10  is configured to create one or more antenna coverage areas for establishing communication with wireless client devices located in the RF range of the antenna coverage areas. The distributed antenna system  10  provides RF communication services (e.g., cellular services). In this embodiment, the distributed antenna system  10  includes head-end equipment (HEE)  12  such as a head-end unit (HEU), one or more RUs  14 , and an optical fiber  16  that optically couples the HEE  12  to the RU  14 . The RU  14  is a type of remote communication unit. In general, a remote communication unit can support wireless communication, wired communication, or both. The RU  14  can support wireless communication and may also support wired communication through wired service port  40 . The HEE  12  is configured to receive communication over downlink electrical RF signals  18 D from a source or sources, such as a network or carrier as examples, and provide such communication to the RU  14 . The HEE  12  is also configured to return communication received from the RU  14 , via uplink electrical RF signals  18 U, back to the source or sources. In this regard in this embodiment, the optical fiber  16  includes at least one downlink optical fiber  16 D to carry signals communicated from the HEE  12  to the RU  14  and at least one uplink optical fiber  16 U to carry signals communicated from the RU  14  back to the HEE  12 . 
     One downlink optical fiber  16 D and one uplink optical fiber  16 U could be provided to support multiple channels each using wave-division multiplexing (WDM), as discussed in U.S. patent application Ser. No. 12/892,424 entitled “Providing Digital Data Services in Optical Fiber-based Distributed Radio Frequency (RF) Communication Systems, And Related Components and Methods,” incorporated herein by reference in its entirety. Other options for WDM and frequency-division multiplexing (FDM) are disclosed in U.S. patent application Ser. No. 12/892,424, any of which can be employed in any of the embodiments disclosed herein. Further, U.S. patent application Ser. No. 12/892,424 also discloses distributed digital data communication signals in a distributed antenna system which may also be distributed in the optical fiber-based distributed antenna system  10  either in conjunction with RF communication signals or not. 
     The optical fiber-based distributed antenna system  10  has an antenna coverage area  20  that can be disposed about the RU  14 . The antenna coverage area  20  of the RU  14  forms an RF coverage area  38 . The HEE  12  is adapted to perform or to facilitate any one of a number of Radio-over-Fiber (RoF) applications, such as RF identification (RFID), wireless local-area network (WLAN) communication, or cellular phone service. Shown within the antenna coverage area  20  is a client device  24  in the form of a mobile device as an example, which may be a cellular telephone as an example. The client device  24  can be any device that is capable of receiving RF communication signals. The client device  24  includes an antenna  26  (e.g., a wireless card) adapted to receive and/or send electromagnetic RF signals. 
     With continuing reference to  FIG. 1 , to communicate the electrical RF signals over the downlink optical fiber  16 D to the RU  14 , to in turn be communicated to the client device  24  in the antenna coverage area  20  formed by the RU  14 , the HEE  12  includes a radio interface in the form of an electrical-to-optical (E/O) converter  28 . The E/O converter  28  converts the downlink electrical RF signals  18 D to downlink optical RF signals  22 D to be communicated over the downlink optical fiber  16 D. The RU  14  includes an optical-to-electrical (O/E) converter  30  to convert received downlink optical RF signals  22 D back to electrical RF signals to be communicated wirelessly through an antenna  32  of the RU  14  to client devices  24  located in the antenna coverage area  20 . 
     Similarly, the antenna  32  is also configured to receive wireless RF communication from client devices  24  in the antenna coverage area  20 . In this regard, the antenna  32  receives wireless RF communication from client device  24  and communicates electrical RF signals representing the wireless RF communication to an E/O converter  34  in the RU  14 . The E/O converter  34  converts the electrical RF signals into uplink optical RF signals  22 U to be communicated over the uplink optical fiber  16 U. An O/E converter  36  provided in the HEE  12  converts the uplink optical RF signals  22 U into uplink electrical RF signals, which can then be communicated as uplink electrical RF signals  18 U back to a network or other source. 
     To provide further exemplary illustration of how a distributed antenna system can be deployed indoors,  FIG. 2A  is provided.  FIG. 2A  is a partially schematic cut-away diagram of a building infrastructure  50  employing an optical fiber-based distributed antenna system. The system may be the optical fiber-based distributed antenna system  10  of  FIG. 1 . The building infrastructure  50  generally represents any type of building in which the optical fiber-based distributed antenna system  10  can be deployed. As previously discussed with regard to  FIG. 1 , the optical fiber-based distributed antenna system  10  incorporates the HEE  12  to provide various types of communication services to coverage areas within the building infrastructure  50 , as an example. 
     For example, as discussed in more detail below, the distributed antenna system  10  in this embodiment is configured to receive wireless RF signals and convert the RF signals into RoF signals to be communicated over the optical fiber  16  to multiple RUs  14 . The optical fiber-based distributed antenna system  10  in this embodiment can be, for example, an indoor distributed antenna system (IDAS) to provide wireless service inside the building infrastructure  50 . These wireless signals can include cellular service, wireless services such as RFID tracking, Wireless Fidelity (WiFi), local area network (LAN), WLAN, public safety, wireless building automations, and combinations thereof, as examples. 
     With continuing reference to  FIG. 2A , the building infrastructure  50  in this embodiment includes a first (ground) floor  52 , a second floor  54 , and a third floor  56 . The floors  52 ,  54 ,  56  are serviced by the HEE  12  through a main distribution frame  58  to provide antenna coverage areas  60  in the building infrastructure  50 . Only the ceilings of the floors  52 ,  54 ,  56  are shown in  FIG. 2A  for simplicity of illustration. In the example embodiment, a main cable  62  has a number of different sections that facilitate the placement of a large number of RUs  14  in the building infrastructure  50 . Each RU  14  in turn services its own coverage area in the antenna coverage areas  60 . The main cable  62  can include, for example, a riser cable  64  that carries all of the downlink and uplink optical fibers  16 D,  16 U to and from the HEE  12 . The riser cable  64  may be routed through a power unit  70 . The power unit  70  may also be configured to provide power to the RUs  14  via an electrical power line provided inside an array cable  72 , or tail cable or home-run tether cable as other examples, and distributed with the downlink and uplink optical fibers  16 D,  16 U to the RUs  14 . For example, as illustrated in the building infrastructure  50  in  FIG. 2B , a tail cable  80  may extend from the power units  70  into an array cable  82 . Downlink and uplink optical fibers in tether cables  84  of the array cables  82  are routed to each of the RUs  14 , as illustrated in  FIG. 2B . Referring back to  FIG. 2A , the main cable  62  can include one or more multi-cable (MC) connectors adapted to connect select downlink and uplink optical fibers  16 D,  16 U, along with an electrical power line, to a number of optical fiber cables  66 . 
     With continued reference to  FIG. 2A , the main cable  62  enables multiple optical fiber cables  66  to be distributed throughout the building infrastructure  50  (e.g., fixed to the ceilings or other support surfaces of each floor  52 ,  54 ,  56 ) to provide the antenna coverage areas  60  for the first, second, and third floors  52 ,  54 , and  56 . In an example embodiment, the HEE  12  is located within the building infrastructure  50  (e.g., in a closet or control room), while in another example embodiment, the HEE  12  may be located outside of the building infrastructure  50  at a remote location. A base transceiver station (BTS)  68 , which may be provided by a second party such as a cellular service provider, is connected to the HEE  12 , and can be co-located or located remotely from the HEE  12 . A BTS  68  is any station or signal source that provides an input signal to the HEE  12  and can receive a return signal from the HEE  12 . 
     In a typical cellular system, for example, a plurality of BTSs is deployed at a plurality of remote locations to provide wireless telephone coverage. Each BTS serves a corresponding cell and when a mobile client device enters the cell, the BTS communicates with the mobile client device. Each BTS can include at least one radio transceiver for enabling communication with one or more subscriber units operating within the associated cell. As another example, wireless repeaters or bi-directional amplifiers could also be used to serve a corresponding cell in lieu of a BTS. Alternatively, radio input could be provided by a repeater, picocell, or femtocell as other examples. 
     The optical fiber-based distributed antenna system  10  in  FIGS. 1-2B  and described above provides point-to-point communication between the HEE  12  and the RU  14 . A multi-point architecture is also possible as well. With regard to  FIGS. 1-2B , each RU  14  communicates with the HEE  12  over a distinct downlink and uplink optical fiber pair to provide the point-to-point communication. Whenever an RU  14  is installed in the optical fiber-based distributed antenna system  10 , the RU  14  is connected to a distinct downlink and uplink optical fiber pair connected to the HEE  12 . The downlink and uplink optical fibers  16 D,  16 U may be provided in a fiber optic cable. Multiple downlink and uplink optical fiber pairs can be provided in a fiber optic cable to service multiple RUs  14  from a common fiber optic cable. 
     For example, with reference to  FIG. 2A , RUs  14  installed on a given floor  52 ,  54 , or  56  may be serviced from the same optical fiber  16 . In this regard, the optical fiber  16  may have multiple nodes where distinct downlink and uplink optical fiber pairs can be connected to a given RU  14 . 
     The HEE  12  may be configured to support any frequencies desired, including but not limited to US FCC and Industry Canada frequencies (824-849 MHz on uplink and 869-894 MHz on downlink), US FCC and Industry Canada frequencies (1850-1915 MHz on uplink and 1930-1995 MHz on downlink), US FCC and Industry Canada frequencies (1710-1755 MHz on uplink and 2110-2155 MHz on downlink), US FCC frequencies (698-716 MHz and 776-787 MHz on uplink and 728-746 MHz on downlink), EU R &amp; TTE frequencies (880-915 MHz on uplink and 925-960 MHz on downlink), EU R &amp; TTE frequencies (1710-1785 MHz on uplink and 1805-1880 MHz on downlink), EU R &amp; TTE frequencies (1920-1980 MHz on uplink and 2110-2170 MHz on downlink), US FCC frequencies (806-824 MHz on uplink and 851-869 MHz on downlink), US FCC frequencies (896-901 MHz on uplink and 929-941 MHz on downlink), US FCC frequencies (793-805 MHz on uplink and 763-775 MHz on downlink), and US FCC frequencies (2495-2690 MHz on uplink and downlink). 
     RUs, including the RUs  14  discussed above, contain power-consuming components for transmitting and receiving RF communication signals. In the situation of an optical fiber-based distributed antenna system, the RUs  14  may contain O/E and E/O converters that also require power to operate. As an example, a RU  14  may contain a power unit that includes a power supply to provide power to the RUs  14  locally at the RU  14 . Alternatively, power may be provided to the RUs  14  from power supplies provided in remote power units such as power units  70 . In either scenario, it may be desirable to provide these power supplies in modular units or devices that may be easily inserted or removed from a power unit. Providing modular power distribution modules allows power to more easily be configured as needed for the distributed antenna system. A power unit, such as power unit  70  may be coupled to one or more RU  14  through respective power output ports. Each power output port represents a connection point. Likewise, each power input port at the RU  14  represents a connection point. As the number of connection points increases, the possibility of misconnecting a power medium to a connection point increases. While installation personnel are trained to be careful about making the proper connections, human error or other factors may result in such improper connections. Manually tracing each connection is time consuming and prone to the same possible sources of error. Accordingly, there is a need for an automated system which automatically maps the power output ports of the power unit  70  to the respective RU  14 . 
     In this regard,  FIGS. 3 and 4  illustrate hardware that facilitates automatic mapping of power connections. In particular,  FIG. 3  illustrates an exemplary power grid and management signal path for distributed antenna system  10 . As alluded to above, there may be a plurality of power units  70 . These are labeled power units  70 A- 70 N (where N is an integer greater than one) in  FIG. 3 . Each power unit  70 A- 70 N may include a respective slave controller  74 A- 74 N. Further, each power unit  70  may include power output ports  76   1 - 76   r  (where r is an integer greater than 1). A power medium  78  is coupled to each power output port  76 . Thus, there are power media  78   1 - 78   r . As illustrated there are a plurality of RUs  14 , and in particular there are M RU  14 A- 14 M (where M is an integer greater than one). Each RU  14  includes a slave controller  90  (e.g., slave controllers  90 A- 90 M) and one or more power input ports  92 . For simplicity, only two power input ports  92  are illustrated for each RU  14 , and are denoted similarly to the RU  14  (e.g., RU  14 A has power input ports  92 A 1  and  92 A 2 ). The power input ports  92  are coupled to a respective power medium  78 . In an exemplary embodiment, the power media  78  are coaxial cables, although other copper conductors are contemplated. 
     With continued reference to  FIG. 3 , a control system  94  may be associated with the HEE  12  or an intermediate control unit (ICU). The control system  94  may include a master controller and appropriate software to effectuate embodiments of the present disclosure. The control system  94  is configured to send a management signal  96  to the power units  70   1 - 70   r  and in particular to the slave controller  74  of the respective power units  70   1 - 70   r . Additionally, the management signal  96  may be sent to the RUs  14 A- 14 M and in particular to the slave controllers  90 A- 90 M. The management signal  96  may be sent to the appropriate destination over optical fiber  16  (see  FIG. 1 ). During installation of the distributed antenna system  10 , the installation personnel must initially install each of the power units  70  and the RU  14 , then extend the optical fiber  16  to each RU  14  as well as extend power media  78  to each RU  14 . The ends of the power media  78  must be coupled to the power unit  70  or the RU  14 . As noted above, as the size of the distributed antenna system  10  grows, the number of connections that need to be made increases and the opportunity for error in installation grows. Likewise, while the installation personnel may make a written or digital record of what connections are believed to have been made, the creation of such records is time consuming and may also have errors contained therein so an automated mapping system which automatically determines and records which power units  70  are connected to which RUs  14 , and in particular which power output ports  76  are connected to which power input ports  92  would be helpful in the creating a record that may be used to detect errors in the connections. 
     With continued reference to  FIG. 3 , the management signal  96  may include instructions to the power unit  70  to generate an alternating current (AC) test signal that is to be combined with the direct current (DC) power signal and sent over the power medium  78  to the RUs  14 . Likewise, the management signal  96  may indicate to the RU  14  that an AC test signal is about to be received and to acknowledge receipt of the AC test signal. By sending out the AC test signal on only one of the power media  78   1 - 78   r , the control system  94  may evaluate which RU  14 A- 14 M responds to the AC test signal and record this information in a database. While it is contemplated that the process will step through the power media  78   1 - 78   r  with different time slots to differentiate the polling process (e.g., analogous to a time division multiple access (TDMA)), the signals may alternatively be frequency divided (e.g., analogous to a frequency division multiple access (FDMA)). This polling process is described in greater detail below with reference to  FIG. 5 . 
     More detail about the power unit  70  and the RU  14  is provided in  FIG. 4 . In this regard, the power unit  70  may include an AC test signal injection circuit  100  that generates an AC test signal  102 . Concurrently, a DC power conditioning circuit  104  generates a DC power signal  106 . The AC test signal  102  and DC power signal  106  are summed by summing point  108  and presented to power output port  76   x  within power output ports  76   1 - 76   r  (inclusive). A capacitor  110  blocks DC signals from interfering with the AC test signal injection circuit  100  and an inductor  112  blocks AC signals from interfering with the DC power conditioning circuit  104 . The AC test signal  102  can be modulated by alarm and messages generator  114  to carry different alarms or messages. 
     With continued reference to  FIG. 4 , the RU  14 A is illustrated in greater detail although it should be appreciated that each of the RUs  14  is substantially similar if not identical to RU  14 A, and the discussion of RU  14 A is applicable to each of the RUs  14 . RU  14 A has z power input ports  92 A (e.g.,  92 A 1 - 92 A z ). The power medium  78  is coupled to the power input port  92 A y  (where y is between 1 and z, inclusive). The RU  14 A receives the combined DC power signal  106  and AC test signal  102  and splits the two signals at splitting point  120 . The DC power signal  106  is provided to the DC power conditioning circuit  122 . An inductor  124  blocks the AC signals from interfering with the DC power conditioning circuit  122 . After conditioning, power is provided to the elements of the RU  14 A, such as a transceiver coupled to antenna  32 , O/E converter  30 , E/O converter  34 , and the like. The AC test signal  102  is passed to the AC test signal detection circuit  126 . A capacitor  128  blocks DC signals from interfering with the AC test signal detection circuit  126 . The slave controller  90  ( FIG. 3 ) is operably coupled to the AC test signal detection circuit  126  and determines that an AC signal has been received. The slave controller  90  then sends a management signal to the control system  94  indicating receipt of the AC test signal  102 . 
     The process  150  of mapping the ports and connections is illustrated in  FIG. 5 . Initially, the process  150  begins with the installation of HEE  12  (block  152 ). Then, the power units  70  are installed (block  154 ). Then, the RUs  14  are installed (block  156 ). Alternatively, the RUs  14  may be installed before the power units  70  without departing from the scope of the present disclosure. The power units  70  are coupled to the RUs  14  with power media  78  (block  158 ). Once the connections are made, the testing and mapping of the present disclosure begins (block  160 ). The test begins by the control system  94  instructing the AC test signal injection circuit  100  to generate the test signal at a given output port  76  and convey the AC test signal over the respective power medium  78  (block  162 ). A multiplexer (MUX) may be used to select which power output port  76  receives the AC test signal. While not shown, the control system  94  may send a signal through the management signal to the RUs  14  that a test signal will be coming in the near future and to reply if the signal is received. The AC test signal is received at the RU  14  (block  164 ). The RU  14  that received the AC test signal generates an acknowledgment signal and transmits the acknowledgment signal to the control system  94  (block  166 ). The acknowledgment signal may be conveyed over the management signal channel and include identifying information about which of the RU  14 A- 14 M sent the acknowledgment signal. The control system  94  receives the acknowledgment signal (block  168 ). The identifying information from the RU  14  is stored with the power output port  76  that was selected at block  162  (block  170 ). The control system  94  determines if the all the power output ports  76  have been tested (block  172 ). If the answer is yes, the process  150  ends (block  174 ). If however, additional power output ports  76  remain to be tested, the control system  94  changes the time or frequency of the test signal generation (block  176 ) and repeats the process as noted. In particular, the control system  94  may step through the power output ports  76  sequentially in time and use the time difference to link the acknowledgment signal to a particular test signal. Alternatively, the control system  94  may use frequency division to differentiate acknowledgment signals. 
     Once the mapping is complete, checks may be run on the data stored from the mapping process and compared to an expected map of connections. The check may be automated or manual as needed or desired and can be used to check not only that ports are coupled to one another correctly, but also that sufficient power is provided to the respective RU  14  based on power demands at the RU  14 . 
       FIG. 6  is a schematic diagram representation of additional detail regarding an exemplary computer system  200  that may be included in the power unit  70  or the RU  14 . The computer system  200  is adapted to execute instructions from an exemplary computer-readable medium to perform power management functions. In this regard, the computer system  200  may include a set of instructions for causing the control system  94 , slave controller  74 , or slave controller  90  to function as previously described. The RU  14  or power unit  70  may be connected (e.g., networked) to other machines in a LAN, an intranet, an extranet, or the Internet. The RU  14  or power unit  70  may operate in a client-server network environment, or as a peer machine in a peer-to-peer (or distributed) network environment. While only a single device is illustrated, the term “device” shall also be taken to include any collection of devices that individually or jointly execute a set (or multiple sets) of instructions to perform any one or more of the methodologies discussed herein. The control system  94 , slave controller  74 , or slave controller  90  may be a circuit or circuits included in an electronic board card, such as a printed circuit board (PCB) as an example, a server, a personal computer, a desktop computer, a laptop computer, a personal digital assistant (PDA), a computing pad, a mobile device, or any other device, and may represent, for example, a server or a user&#39;s computer. 
     The exemplary computer system  200  in this embodiment includes a processing device or processor  202 , a main memory  214  (e.g., read-only memory (ROM), flash memory, dynamic random access memory (DRAM) such as synchronous DRAM (SDRAM), etc.), and a static memory  206  (e.g., flash memory, static random access memory (SRAM), etc.), which may communicate with each other via the data bus  208 . Alternatively, the processing device  202  may be connected to the main memory  214  and/or static memory  206  directly or via some other connectivity means. The processing device  202  may be a controller, and the main memory  214  or static memory  206  may be any type of memory. 
     The processing device  202  represents one or more general-purpose processing devices such as a microprocessor, central processing unit, or the like. More particularly, the processing device  202  may be a complex instruction set computing (CISC) microprocessor, a reduced instruction set computing (RISC) microprocessor, a very long instruction word (VLIW) microprocessor, a processor implementing other instruction sets, or processors implementing a combination of instruction sets. The processing device  202  is configured to execute processing logic in instructions  204  for performing the operations and steps discussed herein. 
     The computer system  200  may further include a network interface device  210 . The computer system  200  also may or may not include an input  212  to receive input and selections to be communicated to the computer system  200  when executing instructions. The computer system  200  also may or may not include an output  222 , including but not limited to a display, a video display unit (e.g., a liquid crystal display (LCD) or a cathode ray tube (CRT)), an alphanumeric input device (e.g., a keyboard), and/or a cursor control device (e.g., a mouse). 
     The computer system  200  may or may not include a data storage device that includes instructions  216  stored in a computer-readable medium  218 . The instructions  224  may also reside, completely or at least partially, within the main memory  214  and/or within the processing device  202  during execution thereof by the computer system  200 , the main memory  214  and the processing device  202  also constituting computer-readable medium  218 . The instructions  216 ,  224  may further be transmitted or received over a network  220  via the network interface device  210 . 
     Further, as used herein, it is intended that terms “fiber optic cables” and/or “optical fibers” include all types of single mode and multi-mode light waveguides, including one or more optical fibers that may be upcoated, colored, buffered, ribbonized and/or have other organizing or protective structure in a cable such as one or more tubes, strength members, jackets or the like. The optical fibers disclosed herein can be single mode or multi-mode optical fibers. Likewise, other types of suitable optical fibers include bend-insensitive optical fibers, or any other expedient of a medium for transmitting light signals. An example of a bend-insensitive, or bend resistant, optical fiber is ClearCurve® Multimode fiber commercially available from Corning Incorporated. Suitable fibers of this type are disclosed, for example, in U.S. Patent Application Publication Nos. 2008/0166094 and 2009/0169163, the disclosures of which are incorporated herein by reference in their entireties. 
     Many modifications and other embodiments of the embodiments set forth herein will come to mind to one skilled in the art to which the embodiments pertain having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. For example, the distributed antenna systems could include any type or number of communication mediums, including but not limited to electrical conductors, optical fiber, and air (i.e., wireless transmission). The distributed antenna systems may distribute any type of communication signals, including but not limited to RF communication signals and digital data communication signals, examples of which are described in U.S. patent application Ser. No. 12/892,424 entitled “Providing Digital Data Services in Optical Fiber-based Distributed Radio Frequency (RF) Communication Systems, And Related Components and Methods,” incorporated herein by reference in its entirety. Multiplexing, such as WDM and/or FDM, may be employed in any of the distributed antenna systems described herein, such as according to the examples provided in U.S. patent application Ser. No. 12/892,424. 
     Unless otherwise expressly stated, it is in no way intended that any method set forth herein be construed as requiring that its steps be performed in a specific order. Accordingly, where a method claim does not actually recite an order to be followed by its steps or it is not otherwise specifically stated in the claims or descriptions that the steps are to be limited to a specific order, it is no way intended that any particular order be inferred. 
     It will be apparent to those skilled in the art that various modifications and variations can be made without departing from the spirit or scope of the invention. Since modifications combinations, sub-combinations and variations of the disclosed embodiments incorporating the spirit and substance of the invention may occur to persons skilled in the art, the invention should be construed to include everything within the scope of the appended claims and their equivalents.