Patent Publication Number: US-10764760-B2

Title: Selective non-distribution of received unlicensed spectrum communication signals by a remote unit(s) into a distributed communications system (DCS)

Description:
PRIORITY APPLICATIONS 
     This application is a continuation of U.S. application Ser. No. 15/831,968, filed Dec. 5, 2017, which is a continuation of U.S. application Ser. No. 15/086,804, filed Mar. 31, 2016, now U.S. Pat. No. 9,924,369. 
    
    
     BACKGROUND 
     The disclosure relates generally to distributed communications systems (DCS), such as distributed antenna systems (DAS) as an example, and more particularly to selective non-distribution of received unlicensed spectrum communications by a remote unit(s) into a DCS. 
     Wireless customers are increasingly demanding digital data services, such as streaming video signals. At the same time, some wireless customers use their wireless communication devices in areas that are poorly serviced by conventional cellular networks, such as inside certain buildings or areas where there is little cellular coverage. One response to the intersection of these two concerns has been the use of DASs. DASs include remote antenna units (RAUs) configured to receive and transmit communications signals to client devices within the antenna range of the RAUs. DASs can be particularly useful when deployed inside buildings or other indoor environments where the wireless communication devices may not otherwise be able to effectively receive RF signals from a source. 
     In this regard,  FIG. 1  illustrates distribution of communications services to remote coverage areas  100 ( 1 )- 100 (N) of a DAS  102 , wherein ‘N’ is the number of remote coverage areas. These communications services can include cellular services, wireless services, such as RF identification (RFID) tracking, Wireless Fidelity (Wi-Fi), local area network (LAN), and wireless LAN (WLAN), wireless solutions (Bluetooth, Wi-Fi Global Positioning System (GPS) signal-based, and others) for location-based services, and combinations thereof, as examples. The remote coverage areas  100 ( 1 )- 100 (N) are created by and centered on RAUs  104 ( 1 )- 104 (N) connected to a centralized equipment  106  (e.g., a head-end controller, a head-end unit, or a central unit). The centralized equipment  106  may be communicatively coupled to a source transceiver  108 , such as for example, a base transceiver station (BTS) or a baseband unit (BBU). In this regard, the centralized equipment  106  receives downlink communications signals  1100  from the source transceiver  108  to be distributed to the RAUs  104 ( 1 )- 104 (N). The downlink communications signals  1100  can include data communications signals and/or communication signaling signals, as examples. The RAUs  104 ( 1 )- 104 (N) are configured to receive the downlink communications signals  110 D from the centralized equipment  106  over a communications medium  112  to be distributed to the respective remote coverage areas  100 ( 1 )- 100 (N) of the RAUs  104 ( 1 )- 104 (N). In a non-limiting example, the communications medium  112  may be a wired communications medium, a wireless communications medium, or an optical fiber-based communications medium. Each of the RAUs  104 ( 1 )- 104 (N) may include an RF transmitter/receiver (not shown) and a respective antenna  114 ( 1 )- 114 (N) operably connected to the RF transmitter/receiver to wirelessly distribute the communications services to user equipment (UE)  116  within the respective remote coverage areas  100 ( 1 )- 100 (N). The RAUs  104 ( 1 )- 104 (N) are also configured to receive uplink communications signals  110 U from the UEs  116  in the respective remote coverage areas  100 ( 1 )- 100 (N) to be distributed to the source transceiver  108 . 
     The source transceiver  108  discussed above with regard to the DAS  102  in  FIG. 1  is configured to transmit licensed spectrum. Licensed spectrum is spectrum (i.e., a signal frequency band) purchased by a carrier for exclusive use for communications services to avoid interference with other carrier communications signals. For example, cellular communications services are provided in licensed spectrum in licensed communications frequency bands between 700 MegaHertz (MHz-1900 MHz. Use of licensed spectrum also allows for communications services in licensed spectrum to be managed. For example, long term evolution (LTE) technology is a managed technology where each UE has to be identified by a LTE base station. The LTE base station controls time slots when the UE can transmit and receive communications signals. However, purchasing licensed spectrum is expensive. On the other hand, unlicensed spectrum is spectrum that is made available for use by any carrier or communication service equipment without licensing. Thus, unlicensed spectrum is advantageously supported by many devices and equipment with communications capabilities to avoid the need to purchase licensed spectrum. For example, 5 GHz is an unlicensed spectrum that is used in access points (APs) for WiFi communications as well as other communications devices, such as cordless phones. In this regard, carriers can advantageously provide BTSs or BBUs designed to transmit communications signals in unlicensed spectrum to take advantage of the additional bandwidth provided by the unlicensed spectrum. In this regard, as shown in  FIG. 2A , the source transceiver  108  may be configured to transmit downlink communications signals  110 D in an unlicensed communications frequency band. As shown in  FIG. 2B , the source transceiver  108  may also be configured to transmit downlink communications signals  110 D (e.g., data and signaling signals) in a licensed communications frequency band and other data communications signals in an unlicensed communications frequency band. However, use of unlicensed spectrum can cause mutual interference issues between a source transceiver and other transceivers both transmitting in the same unlicensed spectrum at the same time. Use of unlicensed spectrum can be even more problematic in DASs, such as the DAS  102  in  FIG. 1 , because the DAS expands the reach of the source transceiver to multiple remote coverage areas. 
     Because of the desire by communications service providers to use unlicensed spectrum to gain additional bandwidth without additional licensing costs, mechanisms have been designed and implemented to avoid or reduce interference issues with use of unlicensed spectrum. One such mechanism is “Listen Before Talk (LBT).” LBT is a mechanism proposed by the 3 rd  Generation Partnership Project (3GPP) for minimizing interferences between two transceivers operating in the same unlicensed channel(s). In this regard, a transceiver can start signal transmission of a communications signal in an unlicensed channel after verifying that the unlicensed channel is free for use, meaning that another transceiver is not presently transmitting signals in the same unlicensed channel. Before transmission, the transceiver first listens to the activity “on the air” i.e., on the unlicensed channel where it intends to transmit), or verifies that the unlicensed channel is not occupied by another transmission. If a transmission in the same unlicensed channel is detected, the transmitter postpones its intended transmission until the unlicensed channel is free. When two transceivers coordinate their activity through use of LBT, each transceiver will have a certain likelihood of finding transmission opportunities where an unlicensed channel is free for transmission signals. However, when a source transceiver, such as a BTS or BBU for example, coupled to a DAS transmits communications signals in unlicensed channels to the DAS for distribution, the source transceiver will have to coordinate its activity with all unlicensed transceivers transmitting signals to the remote units in the DAS (i.e., “seen” by the DAS). This can force the source transceiver to remain silent for long periods, thus significantly lowering the throughput of the communications services supported by the DAS. Even one remote unit distributing unlicensed communications signals in a DAS may be enough to cause a source transceiver to be silent in unlicensed channels for long periods of time. 
     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 
     Embodiments of the disclosure relate to selective non-distribution of received unlicensed spectrum communications by a remote unit(s) into a distributed communications system (DCS). Unlicensed spectrum is frequency bands that anyone is free to use to operate wireless devices. As a non-limiting example, the remote unit can be a remote antenna unit (RAU) in a DCS provided as a distributed antenna system (DAS). In this regard, in one aspect, the DCS is configured to receive communications signals in unlicensed spectrum from a signal source transceiver(s) for communications services. The DCS is configured to distribute and/or receive communications signals in unlicensed spectrum to and/or from one or more remote units forming respective remote communications coverage areas. If communications signals transmitted by the source transceiver(s) into the DCS or received from other devices associated with the DCS are in unlicensed spectrum (e.g., in an unlicensed spectrum channel) that is also being used for transmission of communications signals by other transceiver (e.g., a WiFi access point) at the same time, even for a short period of time, mutual signal interference can occur between the source transceiver and the remote transceiver. In this regard, to reduce or avoid signal interference in unlicensed spectrum, received communications signals by the DCS are monitored for unlicensed spectrum. The remote unit is configured to disable or disconnect the reception and/or transmission of the communications signals in the unlicensed spectrum based on the communication signal activity in the unlicensed spectrum. As non-limiting examples, a remote unit could be configured to disable or disconnect distribution of the communications signals in an unlicensed spectrum based on the receiving the unlicensed spectrum beyond a defined period of time, based on a communications signal activity threshold, and/or based on the throughput impact to the communications services provided by the source transceiver(s). In this manner, the source transceiver does not have to be silenced, such as in a listen before talk (LBT) configuration where the source transceiver can be silenced or silenced for long periods of time during the transmission of the interfering communications signals in the unlicensed spectrum by the remote transceiver. 
     An additional embodiment of the disclosure relates a remote unit in a DCS. The remote unit comprises at least one downlink communications interface configured to receive unlicensed downlink RF communications signals from at least one downlink communications medium. The remote unit also comprises at least one antenna configured to receive unlicensed uplink RF communications signals from user equipment (UE) and communicate the received unlicensed downlink RF communications signals to UE. The remote unit also comprises at least one unlicensed communications signal path configured to receive at least one of the unlicensed uplink RF communications signals and the unlicensed downlink RF communications signals. The at least one unlicensed communications signal path comprises at least one signal path control circuit configured to be selectively controlled to enable and disable the at least one unlicensed communications signal path. The remote unit also comprises at least one uplink communications interface configured to receive the unlicensed uplink RF communications signals for coupling to at least one uplink communications medium. The remote unit also comprises a remote unit controller. The remote unit controller is configured to monitor unlicensed communications signals in the at least one unlicensed communications signal path. The remote unit controller is also configured to determine unlicensed signal activity of the unlicensed communications signals in the at least one unlicensed communications signal path. The remote unit controller is also configured to selectively control the at least one signal path control circuit to disable the at least one unlicensed communications signal path based on the determined unlicensed signal activity exceeding a defined signal activity level. 
     An additional embodiment of the disclosure relates to a method for disabling unlicensed communications services in a remote unit in a DCS. The method comprises receiving unlicensed downlink RF communications signals from at least one downlink communications medium. The method also comprises receiving unlicensed uplink RF communications signals from UE over at least one antenna. The method also comprises communicating the received unlicensed downlink RF communications signals over the least one antenna to UE. The method also comprises receiving unlicensed uplink RF communications signals comprising at least one of the unlicensed uplink RF communications signals and the unlicensed downlink RF communications signals in at least one unlicensed communications signal path. The method also comprises distributing the unlicensed communications signals over at least one uplink communications medium. The method also comprises monitoring the unlicensed communications signals in the at least one unlicensed communications signal path. The method also comprises determining unlicensed signal activity of the unlicensed communications signals in the at least one unlicensed communications signal path. The method also comprises selectively disabling the at least one unlicensed communications signal path based on the determined unlicensed signal activity exceeding a defined signal activity level. 
     An additional embodiment of the disclosure relates to a DCS. The DCS comprises a central unit. The central unit is configured to receive unlicensed uplink RF communications signals over at least one uplink communications medium from a plurality of remote units. The central unit is also configured to distribute the unlicensed uplink RF communications signals to at least one source transceiver. The central unit is also configured to receive unlicensed downlink RF communications signals from the at least one source transceiver. The central unit is also configured to distribute the unlicensed downlink RF communications signals over at least one downlink communications medium to the plurality of remote units. Each remote unit among the plurality of remote units comprises at least one downlink communications interface configured to receive the unlicensed downlink RF communications signals from the at least one downlink communications medium. Each remote unit among the plurality of remote units also comprises at least one antenna configured to receive the unlicensed uplink RF communications signals from UE and distribute the unlicensed downlink RF communications signals to LTE. Each remote unit among the plurality of remote units also comprises at least one unlicensed communications signal path configured to receive at least one of the unlicensed uplink RF communications signals and the unlicensed downlink RF communications signals. The at least one unlicensed communications signal path comprises at least one signal path control circuit configured to be selectively controlled to enable and disable the at least one unlicensed communications signal path. The at least one unlicensed communications signal path also comprises at least one uplink communications interface configured to receive the unlicensed uplink RF communications signals for distributing the unlicensed uplink RF communications signals over the at least one uplink communications medium to be received by the central unit. Each remote unit among the plurality of remote units also comprises a remote unit controller. The remote unit controller is configured to monitor unlicensed communications signals in the at least one unlicensed communications signal path. The remote unit controller is also configured to communicate an unlicensed signal report regarding the unlicensed communications signals in the at least one unlicensed communications signal path for each remote unit among the plurality of remote units to a central controller. The remote unit controller is also configured to selectively control the at least one signal path control circuit to disable the at least one unlicensed communications signal path in response to receipt of an unlicensed disable command. 
     The central controller is configured to receive the unlicensed signal report from each remote unit among the plurality of remote units. The central controller is also configured to determine unlicensed signal activity for each remote unit among the plurality of remote units based on the received unlicensed signal report from each remote unit among the plurality of remote units. The central controller is also configured to selectively communicate an unlicensed disable command to the remote unit controller of at least one remote unit among the plurality of remote units to cause the remote unit controller of the at least one remote unit to disable the at least one signal path control circuit of the at least one remote unit to disable the at least one unlicensed communications signal path of the at least one remote unit, based on the unlicensed signal activity in the plurality of remote units. 
     An additional embodiment of the disclosure relates to a method for disabling unlicensed communications services in a remote unit in a DCS. The method comprises receiving unlicensed uplink RF communications signals over at least one uplink communications medium from a plurality of remote units. The method also comprises distributing the unlicensed uplink RF communications signals to at least one source transceiver. The method also comprises receiving unlicensed downlink RF communications signals from the at least one source transceiver. The method also comprises distributing the unlicensed downlink RF communications signals over at least one downlink communications medium to the plurality of remote units. The method also comprises receiving an unlicensed signal report from each of the plurality of remote units regarding unlicensed communications signals comprising at least one of the unlicensed uplink RF communications signals and the unlicensed downlink RF communications signals in at least one unlicensed communications signal path for the remote unit. The method also comprises determining unlicensed signal activity for each remote unit among the plurality of remote units based on the received unlicensed signal report from each remote unit among the plurality of remote units. The method also comprises selectively communicating an unlicensed disable command to a remote unit controller of at least one remote unit among the plurality of remote units to cause the remote unit controller of the at least one remote unit to disable the at least one unlicensed communications signal path of the at least one remote unit, based on the unlicensed uplink signal activity in the plurality of remote units. 
     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. 
     It is to be understood that both the foregoing general description and the following detailed description are merely exemplary and are intended to provide an overview or framework to understand the nature and character of the claims. 
     The accompanying drawings are included to provide a further understanding of the disclosure, 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 communications system (DCS); 
         FIGS. 2A and 2B  are schematic diagrams illustrating a source transceiver communicating data communication signals and communication signaling signals on unlicensed and licensed spectrum communications signals; 
         FIG. 3A  is a schematic diagram of an exemplary DCS illustrating a source transceiver receiving unlicensed spectrum communications signals from user equipment through remote units in remote coverage areas; 
         FIG. 3B  is a timing diagram illustrating exemplary timing of transmitted communications signals in unlicensed spectrum by user equipment to the remote units in the DCS in  FIG. 3A , to further illustrate free time slots available for the source transceiver to transmit communications signals in the unlicensed spectrum; 
         FIG. 4  is a schematic diagram of an exemplary DCS comprising a plurality of remote units each configured with an unlicensed communications signal path(s) to support distribution of unlicensed communication signals, wherein the unlicensed communications signal path(s) in the remote units are configured to be disabled or disconnected to disable distribution of unlicensed communications signals based on monitored communications signal activity in unlicensed spectrum on the unlicensed communications signal path(s) in the remote units; 
         FIG. 5  is a flowchart illustrating an exemplary process for local control of an unlicensed communications signal path(s) in a remote unit in  FIG. 4  based on monitored communications signal activity in unlicensed spectrum in the unlicensed communications signal path(s) in the remote unit; 
         FIG. 6  is a flowchart illustrating an exemplary process for centralized control of unlicensed communications signal path(s) in the remote units in the DCS in  FIG. 4  based on monitored communications signal activity in unlicensed spectrum in the unlicensed communications signal paths in the remote units; 
         FIG. 7  is a flowchart illustrating another exemplary process for centralized control of unlicensed communications signal paths in the remote units in the DCS in  FIG. 4  based on an aggregate communications signal activity in unlicensed spectrum in the unlicensed communications signal paths in the remote units; 
         FIG. 8  is a table illustrating an exemplary remote unit unlicensed spectrum occupancy report indicating the presence rate of unlicensed spectrum communication signals in the unlicensed communication signal paths of the remote units in the DCS in  FIG. 4 , which can be used to provide centralized control of unlicensed communications signal paths in the remote units; 
         FIG. 9  is a schematic diagram of an exemplary remote unit that can be provided in the DCS of  FIG. 4 , illustrating licensed and unlicensed communications signal paths directed to licensed band circuits and unlicensed band circuits, respectively, and respective switching mechanisms configured to be controlled to disable or disconnect the licensed and unlicensed communications signal path(s) in the remote unit; 
         FIG. 10  is a schematic diagram of an exemplary DCS provided in the form of an optical fiber-based distributed antenna system (DAS) that includes a central unit configured to distribute communications signals over optical fiber to a plurality of remote units, wherein unlicensed communications signal paths in the remote units are configured to be disabled or disconnected to disable distribution of unlicensed communications signals based on monitored communications signal activity in unlicensed spectrum on the unlicensed communications signal path(s) in the remote units; 
         FIG. 11  is a partially schematic cut-away diagram of an exemplary building infrastructure in which a DCS, including but not limited to the DCS in  FIG. 4 , can be provided, wherein unlicensed communications signal paths in the remote units are configured to be disabled or disconnected to disable distribution of unlicensed communications signals based on monitored communications signal activity in unlicensed spectrum on the unlicensed communications signal path(s) in the remote units; and 
         FIG. 12  is a schematic diagram of a generalized representation of an exemplary controller that can be included in any central unit or remote unit in a DCS, wherein the controller is configured to control disabling or disconnecting distribution of unlicensed communications signal paths in remote units to disable distribution of unlicensed communications signals based on monitored communications signal activity in unlicensed spectrum on the unlicensed communications signal path(s) in the remote units, wherein the exemplary computer system is adapted to execute instructions from an exemplary computer readable medium. 
     
    
    
     DETAILED DESCRIPTION 
     Embodiments of the disclosure relate to selective non-distribution of received unlicensed spectrum communications by a remote unit(s) into a distributed communications system (DCS). Unlicensed spectrum is frequency bands that anyone is free to use to operate wireless devices. As a non-limiting example, the remote unit can be a remote antenna unit (RAU) in a DCS provided as a distributed antenna system (DAS). In this regard, in one aspect, the DCS is configured to receive communications signals in unlicensed spectrum from a signal source transceiver(s) for communications services. The DCS is configured to distribute the received communications signals in unlicensed spectrum to one or more remote units forming respective remote communications coverage areas. If communications signals transmitted by the source transceiver(s) into the DCS are in unlicensed spectrum (e.g., in an unlicensed spectrum channel) that is also being used for transmission of communications signals by a remote transceiver (e.g., a WiFi access point) to a remote unit in the DCS at the same time, mutual signal interference can occur between the source transceiver and the remote transceiver. In this regard, to reduce or avoid signal interference in unlicensed spectrum, received communications signals by the remote units are monitored for unlicensed spectrum. The remote unit is configured to disable or disconnect the reception and/or transmission of the communications signals in the unlicensed spectrum based on the communication signal activity in the unlicensed spectrum. As non-limiting examples, a remote unit could be configured to disable or disconnect distribution of the communications signals in an unlicensed spectrum based on the receiving the unlicensed spectrum beyond a defined period of time, based on a communications signal activity threshold, and/or based on the throughput impact to the communications services provided by the source transceiver(s). In this manner, the source transceiver does not have to be silenced, such as in a listen before talk (LBT) configuration where the source transceiver can be silenced or silenced for long periods of time during the transmission of the interfering communications signals in the unlicensed spectrum by the remote transceiver. 
       FIG. 3A  is a schematic diagram of an exemplary an DCS  300  that is configured to support licensed and unlicensed communications signals in licensed and unlicensed spectrum. In this regard, the DCS  300  includes a central unit  302  and a plurality of remote units  304 ( 1 )- 304 (P). For example, the central unit  302  may be included in head-end equipment. The remote units  304 ( 1 )- 304 (P) may be remote antenna units that each include an antenna for communicating wireless communications signals to user equipment (LIE). The central unit  302  is configured to receive licensed downlink RF communications signals  306 L(D) in licensed spectrum and unlicensed downlink RF communications signals  306 U(D) in unlicensed spectrum from a source transceiver  308 . For example, the source transceiver  308  may be a base station transceiver (BTS) or a baseband unit (BBU), as examples. The source transceiver  308  may be configured to support transmission of the unlicensed downlink RF communications signals  306 U(D) in unlicensed spectrum to achieve additional bandwidth beyond supported licensed spectrum, as an example. The central unit  302  is configured to distribute the unlicensed downlink RF communications signals  306 U(D) over downlink communications medium  310 D( 1 )- 310 D(P) to one or more of the remote units  304 ( 1 )- 304 (P) to be distributed to UE  312 ( 1 )- 312 (Q) in the communication range of the remote units  304 ( 1 )- 304 (P). 
     With continuing reference to  FIG. 3A , the remote units  304 ( 1 )- 304 (P) are configured to receive licensed and/or unlicensed uplink RF communications signals  306 L(U)( 1 )- 306 L(U)(Q),  306 U(U)( 1 )- 306 U(U)(Q) from UE  312 ( 1 )- 312 (Q) to be distributed over the uplink communications medium  310 U( 1 )- 310 U(P) to the central unit  302  to be distributed to the source transceiver  308 . For example, the UE  312 ( 1 )- 312 (Q) may include cellular devices that are configured to receive licensed downlink RF communications signals  306 L(D) and transmit licensed uplink RF communications signals  306 L(U) in licensed spectrum. As another example, the UE  312 ( 1 )- 312 (Q) may include unlicensed spectrum communication devices that are configured to receive unlicensed downlink RF communications signals  306 U(D) and transmit unlicensed uplink RF communications signals  306 U(U) in unlicensed spectrum. For example, the UE  312 ( 1 )- 312 (Q) could include access points (APs) that support Wireless Fidelity (WiFi) transmissions in the 5 GigaHertz unlicensed spectrum, for example. 
     Because of the desire by communications service providers to use unlicensed spectrum to gain additional bandwidth without additional licensing costs, mechanisms have been designed and implemented to avoid or reduce interference issues with use of unlicensed spectrum. One such mechanism is “Listen Before Talk (LBT).” LBT is a mechanism proposed by the 3 rd  Generation Partnership Project (3GPP) for minimizing interferences between two transceivers operating in the same unlicensed channel(s). In this regard, using the DCS  300  in  FIG. 3A  as an example, the source transceiver  308  can start transmission of the unlicensed downlink RF communications signal  306 U(D) in an unlicensed channel after verifying that the unlicensed channel is free for use, meaning that another proximity transceiver is not presently transmitting signals in the same unlicensed channel. Before transmission, the source transceiver  308  first listens to the activity “on the air” (i.e., on the unlicensed channel where it intends to transmit), or verifies that the unlicensed channel is not occupied by another transmission. If a transmission in the same unlicensed channel is detected, the source transceiver  308  can postpone its intended transmission until the unlicensed channel is free. When the source transceiver  308  and another transceiver coordinate their activity through use of LBT, each transceiver will have a certain likelihood of finding transmission opportunities where an unlicensed channel is free for transmission signals. 
     However, when the source transceiver  308  coupled to the DCS  300  shown in  FIG. 3A , as an example, transmits unlicensed downlink RF communications signals  306 U(D) in unlicensed channels to the DCS  300  for distribution, the source transceiver  308  coordinates its activity with unlicensed UEs  312 ( 1 )- 312 (Q) transmitting signals to the remote units  304 ( 1 )- 304 (P) in the DCS  300  (i.e., “seen” by the DCS  300 ). The source transceiver  308  avoids transmitting the unlicensed downlink RF communications signals  306 U(D) in the same frequency band or channel at the same time as the UEs  312 ( 1 )- 312 (Q) transmit unlicensed uplink RF communications signals  306 U(U). This is shown in timing diagram  314  in  FIG. 3B , where the timings of transmissions of unlicensed uplink RF communications signals  306 U(U) by UEs  312 ( 1 )- 312 (Q) being received by remote units  304 ( 1 )- 304 ( 2 ),  304 ( 4 )- 304 (P) shown. As shown, only time periods or slots T 1 , T 2 , T 3 , and T 4  are free meaning that no transmissions of unlicensed uplink RF communications signals  306 U(U) by UEs  312 ( 1 )- 312 (Q) are occurring during those time slots. Thus, the source transceiver  308  remains silent except during time slots T 1 , T 2 , T 3 , and T 4 , which are free for transmission of unlicensed downlink RF communications signals  306 D(U), thus effectively limiting the throughput of the communications services in the DCS  300 . Even one remote unit  304 ( 1 )- 304 (P) receiving unlicensed uplink RIF communications signals  306 U(U) may enough to cause the source transceiver  308  to be silent in unlicensed channels for long periods of time. 
     In this regard,  FIG. 4  is a schematic diagram of an exemplary DCS  400  in the form of a DAS that is configured to distribute RF communications signals over communications links to a plurality of remote units forming remote RF communications coverage areas in this example. The DCS  400  is configured to be coupled to a source transceiver  408  to distribute unlicensed downlink RF communications signals  406 U(D) received from the source transceiver  408  to remote units  404 ( 1 )- 404 (P) to be distributed to UE (not shown). As will be discussed in more detail below, the DCS  400  is configured to disable or disconnect distribution of unlicensed communications signals distributed through remote units  404 ( 1 )- 404 (P) based on monitored communications signal activity in unlicensed spectrum on unlicensed communications signal paths in the remote units  404 ( 1 )- 404 (P). In this manner, the source transceiver  408  does not have to be silenced, such as in a listen before talk (LBT) configuration where the source transceiver  408  can be silenced or silenced for long periods of time during the transmission of the interfering unlicensed downlink RF communications signals  406 U(D). Thus, signal interference in unlicensed spectrum can be reduced or avoided, thus improving communication services throughput in the DCS  400  without risking interference that can reduce signal quality. 
     The DCS  400  includes a central unit  402  and the plurality of remote units  404 ( 1 )- 404 (P). For example, the central unit  402  may be included in head-end equipment. The remote units  404 ( 1 )- 404 (P) may be remote antenna units that each include an antenna for communicating wireless communications signals to UE. The central unit  402  is configured to receive unlicensed downlink RF communications signals  406 U(D) in unlicensed spectrum from the source transceiver  408 . For example, the source transceiver  408  may be a base station transceiver (BTS) or a baseband unit (BBU), as examples. The source transceiver  408  may be configured to support transmission of the unlicensed downlink RF communications signals  406 U(D) in unlicensed spectrum to achieve additional bandwidth beyond supported licensed spectrum, as an example. The central unit  402  is configured to distribute the unlicensed downlink RF communications signals  406 U(D) over downlink communications medium  410 D( 1 )- 410 D(P) to remote units  404 ( 1 )- 404 (P) to be distributed to UE in the communication range of the remote units  404 ( 1 )- 404 (P). 
     With continuing reference to  FIG. 4 , the remote units  404 ( 1 )- 404 (P) in the DCS  400  in this example each include a downlink communications interface  416 D( 1 )- 416 D(P) configured to receive the unlicensed downlink RF communications signals  406 U(D) from the central unit  402  over a respective downlink communications medium  410 D( 1 )- 410 D(P). The remote units  404 ( 1 )- 404 (P) each include at least one antenna  418 ( 1 )- 418 (P) configured to receive unlicensed uplink RF communications signals  406 U(U)( 1 )- 406 U(U)(P) from UE and communicate the received unlicensed downlink RF communications signals  406 U(D) to UE. The unlicensed downlink RF communications signals  406 U(D) and unlicensed uplink RF communications signals  406 U(U) are considered unlicensed RF communications signals  406 U. The remote units  404 ( 1 )- 404 (P) also each include a respective uplink communications interface  416 U( 1 )- 416 U(P) each configured to receive the unlicensed uplink RF communications signals  406 U(U)( 1 )- 406 U(U)(P) for coupling to respective uplink communications medium  410 U( 1 )- 410 U(P) for distribution directly or indirectly to the central unit  402 . For example, note that respective uplink communications interfaces  416 U( 1 )- 416 U(P) could be configured to be coupled directly to the central unit  402  or indirectly through an upstream remote unit(s)  404 ( 1 )- 404 (P) configured in a daisy-chain configuration, for distributing unlicensed uplink RF communications signals  406 U(U)( 1 )- 406 (U)(P) to the central unit  402 . Each remote unit  404 ( 1 )- 404 (P) also includes an unlicensed communications signal path  420 U( 1 )- 420 U(P) configured to receive the unlicensed downlink RF communications signals  406 U(D) from the respective downlink communications interfaces  416 D( 1 )- 416 D(P) for processing and to be routed through a receiver  422 ( 1 )- 422 (P) to the antenna  418 ( 1 )- 418 (P). The unlicensed communications signal paths  420 U( 1 )- 420 U(P) are also configured to receive the unlicensed uplink RF communications signals  406 U(U)( 1 )- 406 U(U)(P) from the antenna  418 ( 1 )- 418 (P) to be processed and routed to the respective uplink communications interfaces  416 U( 1 )- 416 U(P) in the remote units  404 ( 1 )- 404 (P). In this example, the unlicensed communications signal paths  420 U( 1 )- 420 U(P) are each comprised of separate respective unlicensed downlink communications signal paths  420 U(D)( 1 )- 420 U(D)(P) and unlicensed uplink communications signal paths  420 U(U)( 1 )- 420 U(U)(P) configured to receive and route respective unlicensed downlink RF communications signals  406 U(D) and unlicensed uplink RF communications signals  406 U(U)( 1 )- 406 U(U)(P) in the respective remote units  404 ( 1 )- 404 (P). 
     With continuing reference to  FIG. 4 , the unlicensed uplink communications signal paths  420 U(U)( 1 )- 420 U(U)(P) each contain respective uplink signal path control circuits  424 U( 1 )- 424 U(P). The uplink signal path control circuits  424 U( 1 )- 424 U(P) are configured to be selectively controlled by respective remote unit controllers  426 ( 1 )- 426 (P) to enable and disable the respective unlicensed uplink communications signal paths  420 U(U)( 1 )- 420 U(U)(P), and thus enable and disable communication of the unlicensed downlink RF communications signals  406 U(D) in the remote units  404 ( 1 )- 404 (P). Also in this example, the unlicensed downlink communications signal paths  420 U(D)( 1 )- 420 U(D)(P) contain respective downlink signal path control circuits  424 D( 1 )- 424 D(P). The downlink signal path control circuits  424 D( 1 )- 424 D(P) can also be configured, if desired, to be selectively controlled by the respective remote unit controllers  426 ( 1 )- 426 (P) to enable and disable the respective unlicensed downlink communications signal paths  420 U(D)( 1 )- 420 U(D)(P), and thus enable and disable communication of the unlicensed downlink RF communications signals  406 U(D) in the remote units  404 ( 1 )- 404 (P). In this regard, the remote unit controllers  426 ( 1 )- 426 (P) are configured to generate uplink and/or downlink commands  428 ( 1 )- 428 (P) to the respective uplink signal path control circuits  424 U( 1 )- 424 U(P) and/or the downlink signal path control circuits  424 D( 1 )- 424 D(P) to disable and enable the respective unlicensed uplink communications signal paths  420 U(U)( 1 )- 420 U(U)(P) and unlicensed downlink communications signal paths  420 U(D)( 1 )- 420 U(D)(P). 
     With continuing reference to  FIG. 4 , in this example, the remote unit controllers  426 ( 1 )- 426 (P) are configured to monitor the unlicensed communications signals (or spectrum) in unlicensed uplink communications signal paths  420 U(U)( 1 )- 420 U(U)(P) and/or unlicensed downlink communications signal paths  420 U(D)( 1 )- 420 U(D)(P) (the unlicensed communications signal paths  420 ). The monitoring of the unlicensed communications signals can be used to determine the unlicensed signal activity level to be taken into consideration for throughput considerations due to the source transceiver  408  transmitting unlicensed downlink RF communications signals  406 U(D)( 1 )- 406 U(D)(P). For example, the receivers  422 ( 1 )- 422 (P) may include sensors that are configured to monitor the received unlicensed uplink RF communications signals  406 U(U)( 1 )- 406 U(U)(P) in the respective unlicensed uplink communications signal paths  420 U(U)( 1 )- 420 U(U)(P). The remote unit controllers  426 ( 1 )- 426 (P) are configured to determine unlicensed signal activity in the respective unlicensed uplink communications signal paths  420 U(U)( 1 )- 420 U(U)(P) and/or unlicensed downlink communications signal paths  420 U(D)( 1 )- 420 U(D)(P) in this example. The remote unit controllers  426 ( 1 )- 426 (P) can then be configured to selectively control the uplink signal path control circuits  424 U( 1 )- 424 U(P) to disable the unlicensed uplink communications signal paths  420 U(U)( 1 )- 420 U(U)(P) based on the determined unlicensed signal activity of the unlicensed communications signals exceeding a defined signal activity level. 
     For example, in the unlicensed uplink communications signal paths  420 U(U)( 1 )- 420 U(U)(P), the uplink signal path control circuits  424 U( 1 )- 424 U(P) may be electrical uplink signal path switches  430 U( 1 )- 430 U(P). In this example, the remote unit controllers  426 ( 1 )- 426 (P) can also be configured to selectively control the downlink signal path control circuits  424 D( 1 )- 424 D(P) to disable the unlicensed downlink communications signal paths  420 U(D)( 1 )- 420 U(D)(P) based on the determined unlicensed signal activity exceeding a defined signal activity level. For example, the downlink signal path control circuits  424 D( 1 )- 424 D(P) may also be electrical downlink signal path switches  430 D( 1 )- 430 D(P). In this manner, when the unlicensed signal activity exceeds a defined signal activity level, the distribution of unlicensed RF communications signals  406 U from the remote units  404 ( 1 )- 404 (P) can be controlled and disabled to allow the source transceiver  408  to transmit unlicensed downlink RF communications signals  406 U(D) with reduced or avoided interference, and without long periods of silence. Note however that in this example, only the unlicensed uplink communications signal paths  420 U(U)( 1 )- 420 U(U)(P) may be disabled. 
     Eventually, in this example, the unlicensed signal activity of the unlicensed communications signals in the unlicensed uplink communications signal paths  420 U will no longer exceed the defined signal activity level in a given remote unit  404 ( 1 )- 404 (P). In this regard, the respective remote unit controllers  426 ( 1 )- 426 (P) are configured to selectively control the uplink and/or downlink signal path control circuits  424 U( 1 )- 424 U(P),  424 D( 1 )- 424 D(P) to enable the unlicensed uplink communications signal paths  420 U(U)( 1 )- 420 U(U)(P) and/or unlicensed downlink communications signal paths  420 U(D)( 1 )- 420 U(D)(P) based on the determined unlicensed signal activity in the unlicensed communications signal paths  420  not exceeding the defined signal activity level. Thus, the remote units  404 ( 1 )- 404 (P) are each individually configured to enable and disable the unlicensed uplink communications signal paths  420 U(U)( 1 )- 420 U(U)(P) and/or unlicensed downlink communications signal paths  420 U(D)( 1 )- 420 U(D)(P) based on the unlicensed signal activity in the unlicensed communications signal path  420  in their respective remote units  404 ( 1 )- 404 (P). This is further exemplified by the exemplary process  500  in  FIG. 5 . 
     With reference to  FIG. 5 , the process of selectively controlling distribution of unlicensed communications signals in a remote unit  404  in the DCS  400  in  FIG. 4  can include receiving unlicensed downlink RF communications signals  406 U(D) from the downlink communications medium  410 D (block  502 ). Unlicensed uplink RF communications signals  406 U(U) are received from a UE over an antenna(s)  418  (block  504 ). The process  500  further includes communicating the received unlicensed downlink RF communications signals  406 U(D) over the antenna  418  to UE (block  506 ). The process  500  further includes receiving the unlicensed uplink RF communications signals  406 U(U) in the unlicensed communications signal path  420  (block  508 ). The process  500  further includes receiving the unlicensed downlink RF communications signals  406 U(D) in the unlicensed communications signal path  420  (block  510 ). The process  500  further includes distributing the unlicensed uplink RF communications signals  406 U(U) over the uplink communications medium  410 U (block  512 ). 
     The process  500  further includes monitoring the unlicensed communications signals in the unlicensed communications signal path  420  (block  514 ). The process  500  further includes a remote unit controller  426  determining unlicensed signal activity in the unlicensed communications signal path  420  (block  516 ). The process  500  further includes the remote unit controller  426  selectively disabling the unlicensed communications signal path  420  based on the determined unlicensed signal activity in the unlicensed communications signal path  420  exceeding a defined signal activity level (block  518 ). When the unlicensed signal activity in the unlicensed communications signal path  420  no longer exceeds the defined signal activity level (block  518 ), the process  500  can include the remote unit controller  426  selectively enabling the unlicensed communications signal path  420  based on the determined unlicensed signal activity in the unlicensed communications signal path  420  not exceeding the defined signal activity level (block  520 ). 
     With reference back to  FIG. 4 , there are different ways in which unlicensed signal activity in the unlicensed communications signal path  420  can be monitored or detected. As one example, the remote unit controllers  426 ( 1 )- 426 (P) may be configured to monitor unlicensed channels in the respective unlicensed communications signal paths  420 . For example, only certain channels within a given frequency band or spectrum may be of interest to be used for transmission of unlicensed downlink RF communications signals  406 U(D) by a source transceiver  408 . In this regard, only unlicensed RF communications signals that occupied the channels of interest may be of concern to avoid interference between the source transceiver  408  and the unlicensed downlink RF communications signals  406 U(D) transmitted to the remote units  404 ( 1 )- 404 (P). In this regard, in this example, the remote unit controllers  426 ( 1 )- 426 (P) can be configured to determine unlicensed channel activity of particular channels of interest in the respective unlicensed communications signal paths  420 . The remote unit controllers  426 ( 1 )- 426 (P) can then selectively control uplink and/or downlink signal path control circuits  424 U( 1 )- 424 U(P),  424 D( 1 )- 424 D(P) to disable the unlicensed uplink communications signal paths  420 U(U)( 1 )- 420 U(U)(P) and optionally, the unlicensed downlink communications signal paths  420 U(D)( 1 )- 420 U(D)(P) based on the determined unlicensed channel activity exceeding a defined activity level for the channels of interest. When the channel activity of the channels of interest in the unlicensed communications signal path  420  no longer exceeds the defined uplink activity level, the remote unit controllers  426 ( 1 )- 426 (P) can then selectively control their respective uplink and/or downlink signal path control circuits  424 U( 1 )- 424 U(P),  424 D( 1 )- 424 D(P) to enable the unlicensed uplink communications signal paths  420 U(U)( 1 )- 420 U(U)(P) and/or the unlicensed downlink communications signal paths  420 U(D)( 1 )- 420 U(D)(P), if applicable. 
     In another example, the remote unit controllers  426 ( 1 )- 426 (P) may be configured to monitor the unlicensed signal occupancy rate in respective unlicensed communications signal paths  420 . For example, if the unlicensed RF communications signals only occupy the frequency band or channels of interest for a limited occupancy rate meaning a certain period of time without a defined time frame, the source transceiver  408  may be able to transmit unlicensed downlink communications RF signals  406 U(D) without interference or with acceptable levels of interference. However, if the unlicensed RF communications signals occupy the frequency band or channels of interest for a higher occupancy rate, the source transceiver  408  may not be able to transmit unlicensed downlink communications RF signals  406 U(D) without interference beyond acceptable levels. In this regard, in this example, the remote unit controllers  426 ( 1 )- 426 (P) can be configured to determine unlicensed signal occupancy rate of the unlicensed RF communications signals in the respective unlicensed communications signal paths  420 U. The remote unit controllers  426 ( 1 )- 426 (P) can then selectively control uplink and/or downlink signal path control circuits  424 U( 1 )- 424 U(P),  424 D( 1 )- 424 D(P) to disable the unlicensed uplink communications signal paths  420 U(U)( 1 )- 420 U(U)(P) and optionally, the unlicensed downlink communications signal paths  420 U(D)( 1 )- 420 U(D)(P), based on the determined unlicensed signal occupancy rate exceeding a defined unlicensed signal occupancy rate. When the channel activity of the channels of interest in the unlicensed communications signal path  420  no longer exceeds the defined unlicensed signal occupancy rate, the remote unit controllers  426 ( 1 )- 426 (P) can then selectively control their respective uplink and/or downlink signal path control circuits  424 U( 1 )- 424 U(P),  424 D( 1 )- 424 D(P) to enable the unlicensed uplink communications signal paths  420 U(U)( 1 )- 420 U(U)(P) and/or the unlicensed downlink communications signal paths  420 U(D)( 1 )- 420 U(D)(P), if applicable. 
     The examples discussed above with regard to the DCS  400  in  FIG. 4  involve the remote unit controllers  426 ( 1 )- 426 (P) providing local unlicensed RF communication signals control based only on communications signal activity of their respective unlicensed communications signal paths  420 . However, uplink communications signal activity in each of remote units  404 ( 1 )- 404 (P) collectively can affect source transceiver  408  transmission of unlicensed downlink RF communications signals  406 U(D). For example, the communications signal activity in one remote unit  404  may be considered high, but the communications signal activity in the other remote units  404 ( 1 )- 404 (P) may be considered low. Thus, the collective communications signal activity in the remote units  404 ( 1 )- 404 (P) may be considered low and acceptable from the perspective of the source transceiver  408  even though the communications signal activity in one remote unit  404  is higher. But, the remote unit controllers  426 ( 1 )- 426 (P) in the DCS  400  in  FIG. 4  are only configured to provide localized control of unlicensed uplink communications signal paths  420 U(U)( 1 )- 420 U(U)(P) and/or the unlicensed downlink communications signal paths  420 U(D)( 1 )- 420 U(D)(P) based only on communications signal activity within its respective remote unit  404 ( 1 )- 104 (P). 
     In this regard, the DCS  400  in  FIG. 4  also includes an optional central controller  432 . The central controller  432  can be provided separate from the central unit  402  or integrated in the central unit  402  and/or as part of the functionality of the central unit  402 . The central controller  432  is configured to receive unlicensed signal reports  434 ( 1 )- 434 (P) from each of the remote units  404 ( 1 )- 404 (P) indicating the communications signal activity within the remote units  404 ( 1 )- 404 (P). In this regard, the remote unit controllers  426 ( 1 )- 426 (P) are configured to monitor the unlicensed communications signal paths  420 U. The remote unit controllers  426 ( 1 )- 426 (P) are configured to monitor and communicate respective unlicensed signal reports  434 ( 1 )- 434 (P) in the unlicensed communications signal paths  420  to the central controller  432  over communications links  436 ( 1 )- 436 (P). Local modems  438 ( 1 )- 438 (P) may be provided to interface with the remote unit controllers  426 ( 1 )- 426 (P) to communicate the unlicensed uplink RF communications signals  406 U(U)( 1 )- 406 U(U)(P) to the central controller  432 . The communications links  436 ( 1 )- 436 (P) may be dedicated links or provided as part of the downlink and/or uplink communications medium  410 D( 1 )- 410 D(P),  410 U( 1 )- 410 U(P). 
     In response, the central controller  432  is configured to receive the unlicensed signal reports  434 ( 1 )- 434 (P) from each of the remote units  404 ( 1 )- 404 (P). The central controller  432  is then configured to determine unlicensed signal activity for the remote units  404 ( 1 )- 404 (P) based on the received unlicensed signal reports  434 ( 1 )- 434 (P) from the remote units  404 ( 1 )- 404 (P). Based on the determined unlicensed signal activity for the remote units  404 ( 1 )- 404 (P), the central controller  432  is configured to selectively communicate an unlicensed disable command to selected remote unit controllers  426 ( 1 )- 426 (P) to cause the selected remote unit controller  426 ( 1 )- 426 (P) to cause the uplink signal path control circuits  424 U( 1 )- 424 U(P) and/or the downlink signal path control circuits  424 D( 1 )- 424 D(P) to disable the selected unlicensed uplink communications signal paths  420 U(U)( 1 )- 420 U(U)(P) and/or unlicensed downlink communications signal paths  420 U(D)( 1 )- 420 U(D)(P). The central controller  432  can send the unlicensed disable command to selected remote unit controllers  426 ( 1 )- 426 (P) based on the aggregate unlicensed signal activity in the remote units  404 ( 1 )- 404 (P). In response, the remote unit controllers  426 ( 1 )- 426 (P) of the selected remote units  404 ( 1 )- 404 (P) selectively control the uplink signal path control circuits  424 U( 1 )- 424 U(P) and/or the downlink signal path control circuits  424 D( 1 )- 424 D(P) to disable the selected unlicensed uplink communications signal paths  420 U(U)( 1 )- 420 U(U)(P) and/or unlicensed downlink communications signal paths  420 U(D)( 1 )- 420 U(D)(P), in response to receipt of an unlicensed disable command from the central controller  432 . The central controller  432  can also send an unlicensed enable command to selected remote unit controllers  426 ( 1 )- 426 (P) based on the aggregate unlicensed signal activity in the remote units  404 ( 1 )- 404 (P), to cause the selected remote unit controllers  426 ( 1 )- 426 (P) to enable the selected unlicensed uplink communications signal paths  420 U(U)( 1 )- 420 U(U)(P) and/or unlicensed downlink communications signal paths  420 U(D)( 1 )- 420 U(D)(P). This is further exemplified by the exemplary process  600  in  FIG. 6 . 
     With reference to  FIG. 6 , the process  600  includes receiving unlicensed uplink RF communications signals  406 U(U)( 1 )- 406 U(U)(P) over the uplink communications medium  410 U from the remote units  404 ( 1 )- 404 (P) (block  602 ). The process  600  also includes distributing the unlicensed uplink RF communications signals  406 U(U)( 1 )- 406 U(U)(P) to the source transceiver  408  (block  604 ) The process  600  also includes receiving unlicensed downlink RF communications signals  406 U(D) from the source transceiver  408  (block  606 ). The process  600  also includes distributing the unlicensed downlink RF communications signals  406 U(D) over the downlink communications medium  410 D to the remote units  404 ( 1 )- 404 (P) (block  608 ). The process  600  also includes receiving an unlicensed signal report  434 ( 1 )- 434 (P) from each of the remote units  404 ( 1 )- 404 (P) in the unlicensed communications signal path  420  for the remote unit  404  (block  610 ). The process  600  also includes the central controller  432  determining unlicensed signal activity for each of the remote units  404 ( 1 )- 404 (P) based on the received unlicensed signal reports  434 ( 1 )- 434 (P) from the remote units  404 ( 1 )- 404 (P) (block  612 ). The process  600  also includes selectively communicating an unlicensed disable command to the remote unit controller  426  of remote unit  404  among the remote units  404 ( 1 )- 404 (P) to cause the remote unit controller  426  to disable the unlicensed communications signal path  420 U of the remote unit  404 , based on the unlicensed signal activity in the remote units  404 ( 1 )- 404 (P) (block  614 ). Once the unlicensed signal activity in the remote units  404 ( 1 )- 404 (P) is such that the unlicensed communications signal path  420  of the remote unit  404  can be enabled, the process  600  includes the central controller  432  selectively communicating an unlicensed enable command to the remote unit controller  426  of the remote unit  404  among the remote units  404 ( 1 )- 404 (P) to cause the remote unit controller  426  of the remote unit  404  to enable the unlicensed communications signal path  420  of the remote unit  404 , based on the unlicensed signal activity in the remote units  404 ( 1 )- 404 (P) (block  616 ). 
     With reference back to  FIG. 4 , there are different ways in which aggregate unlicensed signal activity in the unlicensed communications signal paths  420  can be monitored or detected. For example, the central controller  432  can be configured to selectively communicate the unlicensed disable command to the remote unit controllers  426 ( 1 )- 426 (P) of the selected remote units  404 ( 1 )- 404 (P) based on the determined unlicensed signal activity in a particular remote unit  404  exceeding a defined signal activity level. For example, regardless of the aggregate unlicensed signal activity in the remote units  404 ( 1 )- 404 (P), if the signal activity level in a particular remote unit  404  is higher than a defined signal activity level acceptable for even one (1) remote unit  404 ( 1 )- 404 (P), the central controller  432  can instruct that remote unit  404  to disable unlicensed RF communication signal activity. The central controller  432  can also selectively communicate the unlicensed enable command to the remote unit controllers  426 ( 1 )- 426 (P) of the selected remote units  404 ( 1 )- 404 (P), based on the determined unlicensed signal activity in the selected remote unit  404  no longer exceeding the defined signal activity level. 
     In another example, the central controller  432  can be configured to determine an aggregate unlicensed signal activity in the unlicensed communications signal paths  420  in each of remote units  404 ( 1 )- 404 (P) based on the received unlicensed signal report  434 ( 1 )- 434 (P) from remote units  404 ( 1 )- 404 (P), The central controller  432  can be configured to then selectively communicate an unlicensed disable command to the remote unit controller  426 ( 1 )- 426 (P) of the selected remote unit  404 ( 1 )- 404 (P), based on the determined aggregate unlicensed signal activity exceeding a defined signal activity level. The central controller  432  can be further configured to selectively communicate the unlicensed enable command to the remote unit controller  426 ( 1 )- 426 (P) of the selected remote unit  404 ( 1 )- 404 (P) to enable unlicensed communications based on the determined aggregate unlicensed channel activity not exceeding the defined channel activity level. 
     In another example, the central controller  432  can be configured to selectively communicate the unlicensed disable command to the remote unit controller  426 ( 1 )- 426 (P) of a remote unit  404 ( 1 )- 404 (P) based on the unlicensed signal activity of the remote unit  404 ( 1 )- 404 (P) exceeding a defined channel activity contribution level to the aggregate unlicensed channel activity. 
     In yet another example, the central controller  432  can be configured to determine an aggregate unlicensed channel occupancy of at least one unlicensed RF communications channel in the in the unlicensed communications signal paths  420  in the remote units  404 ( 1 )- 404 (P) based on the received unlicensed signal report  434 ( 1 )- 434 (P) from the remote units  404 ( 1 )- 404 (P). The central controller  432  can selectively communicate the unlicensed disable command to the remote unit controller  426 ( 1 )- 426 (P) of the remote unit  404 ( 1 )- 404 (P) that has an aggregate unlicensed channel occupancy exceeding a defined threshold unlicensed channel occupancy. The central controller  432  can selectively communicate the unlicensed enable command to the remote unit controller  426 ( 1 )- 426 (P) of the remote unit  404 ( 1 )- 404 (P) that has an aggregate unlicensed channel occupancy not exceeding the defined threshold unlicensed channel occupancy.  FIG. 7  is a flowchart that illustrates such an exemplary process  700 . 
     In this regard, the process  700  includes the central controller  432  measuring or monitoring the unlicensed signal activity in the unlicensed uplink communications signal paths  420 U the remote units  404 ( 1 )- 404 (P) based on the unlicensed signal reports  434 ( 1 )- 434 (P), as previously described (block  702 ). Note that this exemplary process is not limited to monitoring the unlicensed signal activity in the unlicensed uplink communications signal paths  420 U, but could also include monitoring of the unlicensed signal activity in the unlicensed downlink communications signal paths  420 D. The central controller  432  calculates the aggregate occupancy rate of the unlicensed channels in the in the unlicensed uplink communications signal paths  420 U based on the unlicensed signal reports  434 ( 1 )- 434 (P) (block  704 ). The central controller  432  determines if the aggregate occupancy rate of the unlicensed channels in the in the unlicensed uplink communications signal paths  420 U for the connected remote units  404 ( 1 )- 404 (P) is above a first defined occupancy threshold (block  706 ). For example,  FIG. 8  shows an exemplary aggregate occupancy rate of unlicensed channels in the unlicensed uplink communications signal paths  420 U of 20.4% for five (5) remote units  404 ( 1 )- 404 ( 5 ). Note that the aggregate occupancy rate of unlicensed channels in the in the unlicensed uplink communications signal path  420 U is not a mere summing of the individual occupancy rates of the remote units  404 ( 1 )- 404 ( 5 ) (i.e., 7%, 5%, 15%, 10%, and 4%), because the antenna coverage areas of certain of the remote units  404 ( 1 )- 404 ( 5 ) may overlap such that unlicensed RF communications signals  406 U are received by multiple of the remote units  404 ( 1 )- 404 (P). 
     If the central controller  432  determines the aggregate occupancy rate of the unlicensed channels in the in the unlicensed uplink communications signal paths  420 U for the connected remote units  404 ( 1 )- 404 (P) is above a first defined occupancy threshold, based on the unlicensed signal reports  434 ( 1 )- 434 (P) from each remote unit  404 ( 1 )- 404 (P), the central controller  432  determines which remote units  404 ( 1 )- 404 (P) have an occupancy such that the unlicensed communications signal activity in such remote unit  404 ( 1 )- 404 (P) should be disabled (block  708 ). The remote units  404 ( 1 )- 404 (P) selected for disabling unlicensed communications signal activity are instructed by the central controller  432  to disable their unlicensed communications signal activity, as previously discussed (block  710 ). If however at block  706 , the central controller  432  determines that aggregate occupancy rate of the unlicensed channels in the in the unlicensed uplink communications signal paths  420 U for the connected remote units  404 ( 1 )- 404 (P) does not exceed the first defined occupancy threshold, the central controller  432  determines if the aggregated occupancy rate of the unlicensed channels in the unlicensed uplink communications signal paths  420 U is below the first defined occupancy threshold (block  712 ). If so, based on the unlicensed signal reports  434 ( 1 )- 434 (P) from the remote units  404 ( 1 )- 404 (P), the aggregated occupancy rate of the unlicensed channels in the unlicensed uplink communications signal paths  420 U does not exceed the first defined occupancy threshold, the central controller  432  instructs the selected remote units  404 ( 1 )- 404 (P) to enable their unlicensed communications signal activity, as previously discussed (block  714 ). 
     Note that in the above examples, that when monitoring of the unlicensed uplink communications signal paths  420 U is discussed, such monitoring can include the monitoring of unlicensed uplink RF communications signals  406 U(U)( 1 )- 406 U(U)(P) only, the unlicensed downlink RF communications signals  406 U(D)( 1 )- 406 U(D)(P) only, or both the unlicensed uplink RF communications signals  406 U(U)( 1 )- 406 U(U)(P) and the unlicensed downlink RF communications signals  406 U(D)( 1 )- 406 U(D)(P) only. Further, all or a subset of the unlicensed uplink communications signal paths  420 U(U)( 1 )- 420 U(U)(P) may be monitored in any of these above discussed scenarios, and in any combination. Further, when enabling and disabling unlicensed communications signal paths is discussed above, such can include the enabling and disabling of the unlicensed uplink communications signal paths  420 U(U)( 1 )- 420 U(U)(P) only, the unlicensed downlink communications signal paths  420 U(D)( 1 )- 420 U(D)(P) only, or both the unlicensed uplink communications signal paths  420 U(U)( 1 )- 420 U(U)(P) and the unlicensed downlink communications signal paths  420 U(D)( 1 )- 420 U(D)(P) only. Further, all or a subset of the unlicensed communications signal paths  420 U( 1 )- 420 U(P) may be disabled and enabled for any of these above discussed scenarios, and in any combination. 
     Note that it is also possible to provide for the remote units  404 ( 1 )- 404 (P) in the DCS  400  in  FIG. 4  to also support licensed communication services. In this regard,  FIG. 9  is an exemplary remote unit  404 - 1  that is similar to a remote unit  404  in the DCS  400  in  FIG. 4 . The remote unit  404 - 1  can be employed as any of the remote units  404 ( 1 )- 404 (P) in  FIG. 4 . Common components between the remote unit  404 - 1  and the remote units  404 ( 1 )- 404 (P) in  FIG. 4  are shown with common element numbers and will not be re-described. 
     With reference to  FIG. 9 , a downlink communications interface  416 D′ is provided that is configured to receive both licensed downlink RF communications signals  406 L(D) and the unlicensed downlink RF communications signals  406 U(D) from the downlink communications medium  410 D. In this example, the downlink communications interface  416 D′ is a downlink optical communications interface with the downlink communications medium  410 D being a downlink optical communications medium. The remote unit  404 - 1  includes the antenna  418  that is configured to receive licensed uplink RF communications signals  406 L(U) from UE, and communicate the received licensed downlink RF communications signals  406 L(D) to UE. The antenna  418  may include a multi-band antenna or multiple antennas to support the desired licensed and unlicensed frequency bands. The remote unit  404 - 1  also includes a licensed communications signal path  420 L that is configured to receive the licensed uplink RF communications signals  406 L(U) and the licensed downlink RF communications signals  406 L(D). An uplink communications interface  416 U′ is configured to receive the unlicensed uplink RF communications signals  406 U(U) and the licensed uplink RF communications signals  406 L(U) for coupling to the uplink communications medium  410 U. In this example, the uplink communications interface  416 U′ is an uplink optical communications interface with the uplink communications medium  410 U being an uplink optical communications medium. 
     With continuing reference to  FIG. 9 , in this example, the licensed communications signal path  420 L is comprised of a licensed uplink communications signal path  420 L(U) configured to receive the licensed uplink RF communications signals  406 L(U), and a licensed downlink communications signal path  420 L(D) configured to receive the licensed downlink RF communications signals  406 L(D). The licensed uplink communications signal path  420 L(U) includes one or more licensed uplink band circuits  900 L(U) configured to process the received licensed uplink RF communications signals  406 L(U). The licensed downlink communications signal path  420 L(D) includes one or more licensed downlink band circuits  900 L(D) configured to process the received licensed downlink RF communications signals  406 L(D). Further, the unlicensed uplink communications signal path  420 U(U) includes one or more unlicensed uplink band circuits  900 U(U) configured to process the received unlicensed uplink RF communications signals  406 U(U). The unlicensed downlink communications signal path  420 U(D) includes one or more unlicensed downlink band circuits  900 U(D) configured to process the received unlicensed downlink RF communications signals  406 U(D). 
     An uplink combiner  902 U is provided and configured to receive the unlicensed uplink RF communications signals  406 U(C) from unlicensed uplink communications signal path  420 U(U) and the licensed uplink RF communications signals  406 L(U) from the licensed uplink communications signal path  420 L(U), and combine these signals into combined uplink RF communications signals  406 C(U). A downlink combiner  902 D is also provided to receive the combined downlink RF communications signals comprising the licensed downlink RF communications signals  406 L(D) and unlicensed downlink RF communications signals  406 U(D), separate them out to provide the unlicensed downlink RF communications signals  406 U(D) to the unlicensed downlink communications signal path  420 U(D), and provide the licensed downlink RF communications signals  406 L(D) to the licensed downlink communications signal path  420 L(D). 
     A DCS configured to selectively not distribute received unlicensed spectrum communications by remote units can be provided as a distributed antenna system (DAS). In this regard,  FIG. 10  is a schematic diagram of exemplary DAS  1000 . The DAS  1000  in this example is an optical fiber-based DAS. The DAS  1000  in this example is comprised of three (3) main components. One or more radio interfaces provided in the form of radio interface modules (RIMs)  1002 ( 1 )- 1002 (T) are provided in a central unit  1004  to receive and process downlink electrical communications signals  1006 D( 1 )- 1006 D(S) prior to optical conversion into downlink optical communications signals. The downlink electrical communications signals  1006 D( 1 )- 1006 D(S) may be received from a base station (not shown) as an example. The RIMs  1002 ( 1 )- 1002 (T) provide both downlink and uplink interfaces for signal processing. The notations “1-S” and “1-T” indicate that any number of the referenced component, 1-S and 1-T, respectively, may be provided. 
     With continuing reference to  FIG. 10 , the central unit  1004  is configured to accept the plurality of RIMs  1002 ( 1 )- 1002 (T) as modular components that can easily be installed and removed or replaced in the central unit  1004 . In one embodiment, the central unit  1004  is configured to support up to twelve (12) RIMs  1002 ( 1 )- 1002 ( 12 ). Each RIM  1002 ( 1 )- 1002 (T) can be designed to support a particular type of radio source or range of radio sources (i.e., frequencies) to provide flexibility in configuring the central unit  1004  and the multi-frequency DAS  1000  to support the desired radio sources. For example, one RIM  1002  may be configured to support the Personal Communication Services (PCS) radio band. Another RIM  1002  may be configured to support the 700 MHz radio band. In this example, by inclusion of these RIMs  1002 , the central unit  1004  could be configured to support and distribute unlicensed and/or licensed communications signals. Licensed communications signals could include both PCS and LTE  700  radio bands, as examples. Unlicensed communications signals could include WiFi signals as an example, RIMs  1002  may be provided in the central unit  1004  that support any licensed frequency bands desired, including but not limited to the US Cellular band, Personal Communication Services (PCS) band, Advanced Wireless Services (AWS) band, 700 MHz band, Global System for Mobile communications (GSM) 900, GSM 1800, and Universal Mobile Telecommunication System (UMTS). The RIMs  1002 ( 1 )- 1002 (T) may also be provided in the central unit  1004  that support any wireless technologies desired, including but not limited to Code Division Multiple Access (CDMA), CDMA200, 1×RTT, Evolution Data Only (EV-DO), UMTS, High-speed Packet Access (HSPA), GSM, General Packet Radio Services (GPRS), Enhanced Data GSM Environment (EDGE), Time Division Multiple Access (TDMA), Long Term Evolution (LTE), iDEN, and Cellular Digital Packet Data (CDPD). 
     The RIMs  1002 ( 1 )- 1002 (T) may be provided in the central unit  1004  that support any frequencies desired, including but not limited to licensed 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). 
     With continuing reference to  FIG. 10 , the downlink electrical communications signals  1006 D( 1 )- 1006 D(S) are provided to a plurality of optical interfaces provided in the form of optical interface modules (OIMs)  1008 ( 1 )- 1008 (W) in this embodiment to convert the unlicensed and/or licensed downlink electrical communications signals  1006 D( 1 )- 1006 D(S) (“downlink electrical communications signals  1006 D( 1 )- 1006 D(S)”) into downlink optical communications signals  1010 D( 1 )- 1010 D(S). The notation “1-W” indicates that any number of the referenced component 1-W may be provided. The OIMs  1008  may be configured to provide one or more optical interface components (OICs) that contain optical-to-electrical (O-E) and electrical-to-optical (E-O) converters, as will be described in more detail below. The OIMs  1008  support the radio bands that can be provided by the RIMs  1002 , including the examples previously described above. 
     The OIMs  1008 ( 1 )- 1008 (W) each include E-O converters to convert the downlink electrical communications signals  1006 D( 1 )- 1006 D(S) into the downlink optical communications signals  1010 D( 1 )- 1010 D(S). The downlink optical communications signals  1010 D( 1 )- 1010 D(S) are communicated over downlink optical fiber communications medium  1012 D to a plurality of remote units provided in the form of remote antenna units  1014 ( 1 )- 1014 (X). The notation “1-X” indicates that any number of the referenced component 1-X may be provided. O-E converters provided in the remote antenna units  1014 ( 1 )- 1014 (X) convert the downlink optical communications signals  1010 D( 1 )- 1010 D(S) back into the downlink electrical communications signals  1006 D( 1 )- 1006 D(S), which are provided to antennas  1016 ( 1 )- 1016 (X) in the remote antenna units  1014 ( 1 )- 1014 (X) to user equipment (not shown) in the reception range of the antennas  1016 ( 1 )- 1016 (X). 
     E-O converters are also provided in the remote antenna units  1014 ( 1 )- 1014 (X) to convert licensed and/or unlicensed uplink electrical communications signals  1020 U( 1 )- 1020 U(X) (“uplink electrical communications signals  1020 U( 1 )- 1020 U(X)”) received from user equipment (not shown) through the antennas  1016 ( 1 )- 1016 (X) into uplink optical communications signals  1010 U( 1 )- 1010 U(S). The remote antenna units  1014 ( 1 )- 1014 (X) communicate the uplink optical communications signals  1010 U( 1 )- 1010 U(S) over an uplink optical fiber communications medium  1012 U to the OIMs  1008 ( 1 )- 1008 (W) in the central unit  1004 . The OIMs  1008 ( 1 )- 1008 (W) include O-E converters that convert the received uplink optical communications signals  1010 U( 1 )- 1010 U(S) into uplink electrical communications signals  1022 U( 1 )- 1022 U(X), which are processed by the RIMs  1002 ( 1 )- 1002 (T) and provided as uplink electrical communications signals  1022 U( 1 )- 1022 U(X). The central unit  1004  may provide the uplink electrical communications signals  1022 U( 1 )- 1022 U(X) to a source transceiver such as a base station or other communications system. 
     Note that the downlink optical fiber communications medium  1012 D and uplink optical fiber communications medium  1012 U connected to each remote antenna unit  1014 ( 1 )- 1014 (X) may be a common optical fiber communications medium, wherein for example, wave division multiplexing (WDM) may be employed to provide the downlink optical communications signals  1010 D( 1 )- 1010 D(S) and the uplink optical communications signals  1010 U( 1 )- 1010 U(S) on the same optical fiber communications medium. 
     With continuing reference to  FIG. 10 , the remote antenna unit  1014 (X) is a radio source remote antenna unit. The remote antenna unit  1014 (X) is directly communicatively coupled to a remote radio source  1024 (R) through a direct communicative coupling  1026 (R). The radio source remote antenna unit  1014 (X) is configured to receive remote downlink communications signals  1020 D(R) from the remote radio source  1024 (R) to be distributed to one or more of other remote antenna units  1014 ( 1 )- 1014 (X−1). In this example, the radio source remote antenna unit  1014 (X) distributes the received remote downlink communications signals  1020 D(R) to the central unit  1004  to then be distributed to one or more other remote antenna units  1014 ( 1 )- 1014 (X−1). However, the radio source remote antenna unit  1014 (X) could also be configured to distribute the received remote downlink communications signals  1020 D(R) directly to one or more other remote antenna units  1014 ( 1 )- 1014 (X−1) in a daisy-chain configuration, if the remote antenna units  1014 ( 1 )- 1014 (X) in the DAS  1000  were configured in a daisy-chain configuration. All of the exemplary discussion above with regard to radio source remote units, remote radio sources, and DCSs can be applied to the example DAS  1000  in  FIG. 10 . 
     A DCS configured to selectively not distribute received unlicensed spectrum communications by remote units, such as DCS  400  in  FIG. 4 , may be provided in an indoor environment, such as illustrated in  FIG. 11 . In this regard,  FIG. 11  is a partially schematic cut-away diagram of a building infrastructure  1100  employing a DAS  1102  configured to evaluate performance of remote units on a per remote unit basis, as described above. The building infrastructure  1100  in this embodiment includes a first (ground) floor  1104 ( 1 ), a second floor  1104 ( 2 ), and a third floor  1104 ( 3 ). The floors  1104 ( 1 )- 1104 ( 3 ) are serviced by the central unit  1106  to provide the antenna coverage areas  1108  in the building infrastructure  1100 . The central unit  1106  is communicatively coupled to a base station  1109  to receive downlink communications signals  1114 D from the base station  1109 . The base station  1109  may be coupled to an operational and support system (OSS)  1110  to receive data about the performance of remote antenna units  1112  in the DAS  1102  on a per remote unit basis for determining DAS optimizations. The central unit  1106  is communicatively coupled to the remote antenna units  1112  to receive uplink communications signals  1114 U from the remote antenna units  1112 , similar to as previously discussed above for other DASs. The downlink and uplink communications signals  1114 D,  1114 U communicated between the central unit  1106  and the remote antenna units  1112  are carried over a riser cable  1116  in this example. The riser cable  1116  may be routed through interconnect units (ICUs)  1118 ( 1 )- 1118 ( 3 ) dedicated to each floor  1104 ( 1 )- 1104 ( 3 ) that route the downlink and uplink communications signals  1114 D,  1114 U to the remote antenna units  1112  and also provide power to the remote antenna units  1112  via array cables  1120 ( 1 )- 1120 ( 6 ). 
       FIG. 12  is a schematic diagram representation of additional detail illustrating a computer system  1200  that could be employed in a controller, including the remote unit controller and/or the central controller described above in a DCS, for selectively not distributing received unlicensed spectrum communications by remote units. In this regard, the computer system  1200  is adapted to execute instructions from an exemplary computer-readable medium to perform these and/or any of the functions or processing described herein. 
     In this regard, the computer system  1200  in  FIG. 12  may include a set of instructions that may be executed to predict frequency interference to avoid or reduce interference in a multi-frequency DAS. The computer system  1200  may be connected (e.g., networked) to other machines in a LAN, an intranet, an extranet, or the Internet. 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 computer system  1200  may be a circuit or circuits included in an electronic board card, such as, a printed circuit board (PCB), 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  1200  in this embodiment includes a processing device or processor  1202 , a main memory  1204  (e.g., read-only memory (ROM), flash memory, dynamic random access memory (DRAM), such as synchronous DRAM (SDRAM), etc.), and a static memory  1206  (e.g., flash memory, static random access memory (SRAM), etc. which may communicate with each other via a data bus  1208 . Alternatively, the processor  1202  may be connected to the main memory  1204  and/or static memory  1206  directly or via some other connectivity means. The processor  1202  may be a controller, and the main memory  1204  or static memory  1206  may be any type of memory. 
     The processor  1202  represents one or more general-purpose processing devices, such as a microprocessor, central processing unit, or the like. More particularly, the processor  1202  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 other processors implementing a combination of instruction sets. The processor  1202  is configured to execute processing logic in instructions for performing the operations and steps discussed herein. 
     The computer system  1200  may further include a network interface device  1210 . The computer system  1200  also may or may not include an input  1212 , configured to receive input and selections to be communicated to the computer system  1200  when executing instructions. The computer system  1200  also may or may not include an output  1214 , 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  1200  may or may not include a data storage device that includes instructions  1216  stored in a computer-readable medium  1218 . The instructions  1216  may also reside, completely or at least partially, within the main memory  1204  and/or within the processor  1202  during execution thereof by the computer system  1200 , the main memory  1204  and the processor  1202  also constituting computer-readable medium. The instructions  1216  may further be transmitted or received over a network  1220  via the network interface device  1210 . 
     While the computer-readable medium  1218  is shown in an exemplary embodiment to be a single medium, the term “computer-readable medium” should be taken to include a single medium or multiple media (e.g., a centralized or distributed database, and/or associated caches and servers) that store the one or more sets of instructions. The term “computer-readable medium” shall also be taken to include any medium that is capable of storing, encoding, or carrying a set of instructions for execution by the processing device and that cause the processing device to perform any one or more of the methodologies of the embodiments disclosed herein. The term “computer-readable medium” shall accordingly be taken to include, but not be limited to, solid-state memories, optical medium, and magnetic medium. 
     The embodiments disclosed herein include various steps. The steps of the embodiments disclosed herein may be formed by hardware components or may be embodied in machine-executable instructions, which may be used to cause a general-purpose or special-purpose processor programmed with the instructions to perform the steps. Alternatively, the steps may be performed by a combination of hardware and software. 
     The embodiments disclosed herein may be provided as a computer program product, or software, that may include a machine-readable medium (or computer-readable medium) having stored thereon instructions, which may be used to program a computer system (or other electronic devices) to perform a process according to the embodiments disclosed herein. A machine-readable medium includes any mechanism for storing or transmitting information in a form readable by a machine (e.g., a computer). For example, a machine-readable medium includes: a machine-readable storage medium (e.g., ROM, random access memory (“RAM”), a magnetic disk storage medium, an optical storage medium, flash memory devices, etc.); and the like. 
     Unless specifically stated otherwise and as apparent from the previous discussion, it is appreciated that throughout the description, discussions utilizing terms such as “processing,” “computing,” “determining,” “displaying,” or the like, refer to the action and processes of a computer system, or similar electronic computing device, that manipulates and transforms data and memories represented as physical (electronic) quantities within the computer system&#39;s registers into other data similarly represented as physical quantities within the computer system memories or registers or other such information storage, transmission, or display devices. 
     The algorithms and displays presented herein are not inherently related to any particular computer or other apparatus. Various systems may be used with programs in accordance with the teachings herein, or it may prove convenient to construct more specialized apparatuses to perform the required method steps. The required structure for a variety of these systems will appear from the description above. In addition, the embodiments described herein are not described with reference to any particular programming language. It will be appreciated that a variety of programming languages may be used to implement the teachings of the embodiments as described herein. 
     Those of skill in the art will further appreciate that the various illustrative logical blocks, modules, circuits, and algorithms described in connection with the embodiments disclosed herein may be implemented as electronic hardware, instructions stored in memory or in another computer-readable medium and executed by a processor or other processing device, or combinations of both. The components of the distributed antenna systems described herein may be employed in any circuit, hardware component, integrated circuit (IC), or IC chip, as examples. Memory disclosed herein may be any type and size of memory and may be configured to store any type of information desired. To clearly illustrate this interchangeability, various illustrative components, blocks, modules, circuits, and steps have been described above generally in terms of their functionality. How such functionality is implemented depends on the particular application, design choices, and/or design constraints imposed on the overall system. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present embodiments. 
     The various illustrative logical blocks, modules, and circuits described in connection with the embodiments disclosed herein may be implemented or performed with a processor, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA), or other programmable logic device, a discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. Furthermore, a controller may be a processor. A processor may be a microprocessor, but in the alternative, the processor may be any conventional processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices (e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration). 
     The embodiments disclosed herein may be embodied in hardware and in instructions that are stored in hardware, and may reside, for example, in RAM, flash memory, ROM, Electrically Programmable ROM (EPROM), Electrically Erasable Programmable ROM (EEPROM), registers, a hard disk, a removable disk, a CD-ROM, or any other form of computer-readable medium known in the art. An exemplary storage medium is coupled to the processor such that the processor can read information from, and write information to, the storage medium. In the alternative, the storage medium may be integral to the processor. The processor and the storage medium may reside in an ASIC. The ASIC may reside in a remote station. In the alternative, the processor and the storage medium may reside as discrete components in a remote station, base station, or server. 
     It is also noted that the operational steps described in any of the exemplary embodiments herein are described to provide examples and discussion. The operations described may be performed in numerous different sequences other than the illustrated sequences. Furthermore, operations described in a single operational step may actually be performed in a number of different steps. Additionally, one or more operational steps discussed in the exemplary embodiments may be combined. Those of skill in the art will also understand that information and signals may be represented using any of a variety of technologies and techniques. For example, data, instructions, commands, information, signals, bits, symbols, and chips, that may be references throughout the above description, may be represented by voltages, currents, electromagnetic waves, magnetic fields, or particles, optical fields or particles, or any combination thereof. 
     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 in 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.