WO2011139939A1

WO2011139939A1 - Optical fiber-based distributed communications systems, and related components and methods

Info

Publication number: WO2011139939A1
Application number: PCT/US2011/034733
Authority: WO
Inventors: Igor Berlin; Michael Sauer; Gerald B Schmidt
Original assignee: Corning Cable Systems Llc
Priority date: 2010-05-02
Filing date: 2011-05-02
Publication date: 2011-11-10

Abstract

Optical fiber-based distributed communications systems are disclosed herein. The optical fiber-based distributed communications systems support a variety of features. These features include, but are not limited to, the ability to distribute both radio frequency (RF) communication services and digital data services in the optical fiber-based distributed communications systems. Flexibility is provided in the components of the optical fiber-based distributed communications systems to provide upgradability and other enhanced features. The optical fiber-based distributed communications systems disclosed herein can provide features that support scalability, upgradability, reliability, management, capacity, and enhanced coverage areas. They comprise a plurality of radio interface modules, each adapted to support a given radio frequency band and to distribute received downlink RF communication signals, and a plurality of optical interfaces adapted to convert the downlink RF signals from the radio interface modules into a plurality of downlink optical RF communication signals.

Description

OPTICAL FIBER-BASED DISTRIBUTED COMMUNICATIONS SYSTEMS, AND RELATED COMPONENTS AND METHODS

RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Application No. 61/330,383, filed on May 2, 2010 and entitled, "OPTICAL FIBER-BASED DISTRIBUTED COMMUNICATIONS SYSTEMS, AND RELATED COMPONENTS AND METHODS," which is incorporated herein by reference in its entirety.

BACKGROUND

Field of the Disclosure

[0002] The technology of the disclosure relates to optical fiber-based distributed communications systems for distributing radio frequency (RF) signals over optical fiber.

Technical Background

[0003] Wireless communication is rapidly growing, with ever-increasing demands for high-speed mobile data communication. As an example, so-called "wireless fidelity" or "WiFi" systems and wireless local area networks (WLANs) are being deployed in many different types of areas (e.g., coffee shops, airports, libraries, etc.). Distributed communications systems communicate with wireless devices called "clients," which must reside within the wireless range or "cell coverage area" in order to communicate with an access point device.

[0004] One approach to deploying a distributed communications system involves the use of radio frequency (RF) antenna coverage areas, also referred to as "antenna coverage areas." Antenna coverage areas can have a radius in the range from a few meters up to twenty meters as an example. Combining a number of access point devices creates an array of antenna coverage areas. Because the antenna coverage areas each cover small areas, there are typically only a few users (clients) per antenna coverage area. This allows for minimizing the amount of RF bandwidth shared among the wireless system users. It may be desirable to provide antenna coverage areas in a building or other facility to provide distributed communications system access to clients within the building or facility. However, it may be desirable to employ optical fiber to distribute communication signals. One of the benefits of optical fiber is increased bandwidth. [0005] One type of distributed communications system for creating antenna coverage areas, called "Radio-over-Fiber" or "RoF," utilizes RF signals sent over optical fibers. Such systems can include a head-end station optically coupled to a plurality of remote antenna units that each provide an antenna coverage area. Each remote antenna unit can include an RF transceiver coupled to an antenna to transmit RF signals wirelessly, and each the remote antenna unit is are coupled to the head-end station via an optical fiber link. The RF transceivers in the remote antenna units are transparent to the RF signals. The remote antenna units convert incoming optical RF signals from an optical fiber downlink to electrical RF signals via optical-to-electrical (O/E) converters, which are then passed to the RF transceiver. The RF transceiver converts the electrical RF signals to electromagnetic signals via antennas coupled to the RF transceiver provided in the remote antenna units. The antennas also receive electromagnetic signals, i.e., wireless electromagnetic radiation, from clients in the antenna coverage area and convert them to electrical RF signals (i.e., electrical RF signals in wire). The remote antenna units then convert the electrical RF signals to optical RF signals via electrical-to -optical (E/O) converters. The optical RF signals are then sent over an optical fiber uplink to the headend station.

SUMMARY OF THE DETAILED DESCRIPTION

[0006] Embodiments disclosed in the detailed description include optical fiber-based distributed communications systems that support a variety of features. These features include, but are not limited to, the ability to distribute both RF communication services and digital data services in the optical fiber-based distributed communications systems. Flexibility is provided in the components of the optical fiber-based distributed communications systems to provide upgradability and other enhanced features. The optical fiber-based distributed communications systems disclosed herein can provide features that support scalability, upgradability, reliability, management, capacity, and enhanced coverage areas.

[0007] Additional features are set out in the detailed description which follows, and in part will be readily apparent to those skilled in the art from that description or recognized by practicing the embodiments as described herein, including the detailed description that follows, the claims, as well as the appended drawings.

[0008] It is to be understood that both the foregoing general description and the following detailed description present embodiments, and are intended to provide an overview or framework for understanding the nature and character of the disclosure. The accompanying drawings are included to provide a further understanding, and are incorporated into and constitute a part of this specification. The drawings illustrate various embodiments, and together with the description serve to explain the principles and operation of the concepts disclosed.

BRIEF DESCRIPTION OF THE FIGURES

[0009] FIG. 1 is a schematic diagram of an exemplary optical fiber-based distributed communications system;

[0010] FIG. 2 is a more detailed schematic diagram of an exemplary head-end unit (HEU) and a remote antenna unit (RAU) that can be deployed in the optical fiber-based distributed communications system of FIG. 1;

[0011] FIG. 3 is a partially schematic cut-away diagram of an exemplary building infrastructure in which the optical fiber-based distributed communications system in FIG. 1 can be employed;

[0012] FIG. 4 is a schematic diagram of another exemplary optical fiber-based distributed communications system;

[0013] FIG. 5 is a more detailed schematic diagram of the exemplary optical fiber- based distributed communications system of FIG. 4;

[0014] FIG. 6 is a schematic diagram of an exemplary HEU that can be employed in the optical fiber-based distributed communications systems of FIG. 4 and 5;

[0015] FIG. 7 is a schematic diagram of an exemplary RAU that can be employed in the optical fiber-based distributed communications systems of FIG. 4 and 5;

[0016] FIG. 8 is a schematic diagram of an exemplary building infrastructure in which digital data services and RF communication services are provided in an optical fiber-based distributed communications system;

[0017] FIG. 9 is a schematic diagram of an exemplary Multiple Input/Multiple Output (MIMO) communication scheme that can be employed in the optical fiber-based distributed communications systems of FIGS. 4 and 5;

[0018] FIG. 10 is a schematic diagram an alternate exemplary MIMO communication scheme that can be employed in the optical fiber-based distributed communications systems of FIGS. 4 and 5; [0019] FIG. 11 is a schematic diagram of exemplary multiple HEUs provided to support multiple optical fiber-based distributed communications systems at different locations or facilities under common control and/or management;

[0020] FIG. 12 is a schematic diagram of exemplary multiple remote HEUs provided to support multiple optical fiber-based distributed communications systems at different locations or facilities under management of an exemplary main end HEU;

[0021] FIG. 13 is a schematic diagram of providing multiple optical fiber-based distributed communications systems, each providing different communication services, in a single facility or infrastructure;

[0022] FIG. 14 is a schematic diagram of multiple optical fiber-based distributed communications systems, each providing different communication services, in a single facility or infrastructure over a shared fiber optic cable;

[0023] FIG. 15 is a schematic diagram of exemplary optical fiber-based distributed communications systems providing multiple communication services in common RAUs employing separate amplifiers for each communication service; and

[0024] FIG. 16 is a schematic diagram of exemplary optical fiber-based distributed communications systems providing multiple communication services via shared amplifiers provided in common RAUs.

DETAILED DESCRIPTION

[0025] Reference will now be made in detail to the embodiments, examples of which are illustrated in the accompanying drawings, in which some, but not all embodiments are shown. Indeed, the concepts may be embodied in many different forms and should not be construed as limiting herein; rather, these embodiments are provided so that this disclosure will satisfy applicable legal requirements. Whenever possible, like reference numbers will be used to refer to like components or parts.

[0026] Embodiments disclosed in the detailed description include optical fiber-based distributed communications systems that support a variety of features. These features include, but are not limited to, the ability to distribute both RF communication services and digital data services in the optical fiber-based distributed communications systems. Flexibility is provided in the components of the optical fiber-based distributed communications systems to provide upgradability and other enhanced features. The optical fiber-based distributed communications systems disclosed herein can provide features that support scalability, upgradability, reliability, management, capacity, and enhanced coverage areas. [0027] In this regard, FIG. 1 is a schematic diagram of an embodiment of an optical fiber-based distributed communications system. In this embodiment, the system is an optical fiber-based distributed communications system 10 that is configured to create one or more antenna coverage areas for establishing communications with wireless client devices located in the radio frequency (RF) range of the antenna coverage areas. The optical-fiber based distributed communications system 10 provides RF communications service (e.g., cellular services). In this embodiment, the optical fiber-based distributed communications system 10 includes a head-end unit (HEU) 12, one or more remote antenna units (RAUs) 14, and an optical fiber 16 that optically couples the HEU 12 to the RAU 14. The HEU 12 is configured to receive communications over downlink electrical RF signals 18D from a source or sources, such as a network or carrier as examples, and provide such communications to the RAU 14. The HEU 12 is also configured to return communications received from the RAU 14, via uplink electrical RF signals 18U, back to the source or sources. In this regard and in this embodiment, the optical fiber 16 includes at least one downlink optical fiber 16D to carry signals communicated from the HEU 12 to the RAU 14 and at least one uplink optical fiber 16U to carry signals communicated from the RAU 14 back to the HEU 12.

[0028] The optical fiber-based distributed communications system 10 has an antenna coverage area 20 that can be substantially centered about the RAU 14. The antenna coverage area 20 of the RAU 14 forms an RF coverage area 21. The HEU 12 is adapted to perform or to facilitate any one of a number of Radio-over-Fiber (RoF) applications, such as radio frequency (RF) identification (RFID), wireless local-area network (WLAN) communication, or cellular phone service. Shown within the antenna coverage area 20 is a client device 24 in the form of a mobile device as an example, which may be a cellular telephone as an example. The client device 24 can be any device that is capable of receiving RF communication signals. The client device 24 includes an antenna 26 (e.g., a wireless card) adapted to receive and/or send electromagnetic RF signals.

[0029] With continuing reference to FIG. 1, to communicate the electrical RF signals over the downlink optical fiber 16D to the RAU 14, to in turn be communicated to the client device 24 in the antenna coverage area 20 formed by the RAU 14, the HEU 12 includes an electrical-to-optical (E/O) converter 28. The E-0 converter 28 converts the downlink electrical RF signals 18D to downlink optical RF signals 22D to be communicated over the downlink optical fiber 16D. The RAU 14 includes an optical-to- electrical (O/E) converter 30 to convert received downlink optical RF signals 22D back to electrical RF signals to be communicated wirelessly through an antenna 32 of the RAU 14 to client devices 24 located in the antenna coverage area 20.

[0030] Similarly, the antenna 32 is also configured to receive wireless RF communications from client devices 24 in the antenna coverage area 20. In this regard, the antenna 32 receives wireless RF communications from client devices 24 and communicates electrical RF signals representing the wireless RF communications to an E/O converter 34 in the RAU 14. The E-0 converter 34 converts the electrical RF signals into uplink optical RF signals 22U to be communicated over the uplink optical fiber 16U. An O/E converter 36 provided in the HEU 12 converts the uplink optical RF signals 22U into uplink electrical RF signals, which can then be communicated as uplink electrical RF signals 18U back to a network or other source. The HEU 12 in this embodiment is not able to distinguish the location of the client devices 24 in this embodiment. The client device 24 could be in the range of any antenna coverage area 20 formed by an RAU 14.

[0031] FIG. 2 is a more detailed schematic diagram of the exemplary optical fiber- based distributed communications system of FIG. 1 that provides electrical RF service signals for a particular RF service or application. In an exemplary embodiment, the HEU 12 includes a service unit 37 that provides electrical RF service signals by passing (or conditioning and then passing) such signals from one or more outside networks 38 via a network link 39. In a particular example embodiment, this includes providing WLAN signal distribution as specified in the Institute of Electrical and Electronics Engineers (IEEE) 802.11 standard, i.e., in the frequency range from 2.4 to 2.5 GigaHertz (GHz) and from 5.0 to 6.0 GHz. Any other electrical RF signal frequencies are possible for other embodiments. In another exemplary embodiment, the service unit 37 provides electrical RF service signals by generating the signals directly. In another exemplary embodiment, the service unit 37 coordinates the delivery of the electrical RF service signals between client devices 24 within the antenna coverage area 20.

[0032] With continuing reference to FIG. 2, the service unit 37 is electrically coupled to the E-0 converter 28 that receives the downlink electrical RF signals 18D from the service unit 37 and converts them to corresponding downlink optical RF signals 22D. In an exemplary embodiment, the E-0 converter 28 includes a laser suitable for delivering sufficient dynamic range for the RoF applications described herein, and optionally includes a laser driver/amplifier electrically coupled to the laser. Examples of suitable lasers for the E-0 converter 28 include, but are not limited to, laser diodes, distributed feedback (DFB) lasers, Fabry-Perot (FP) lasers, and vertical cavity surface emitting lasers (VCSELs).

[0033] With continuing reference to FIG. 2, the HEU 12 also includes the O-E converter 36, which is electrically coupled to the service unit 37. The O-E converter 36 receives the uplink optical RF signals 22U and converts them to corresponding uplink electrical RF signals 18U. In an example embodiment, the O-E converter 36 is a photo detector, or a photodetector electrically coupled to a linear amplifier. The E-0 converter 28 and the O-E converter 36 constitute a "converter pair" 35, as illustrated in FIG. 2.

[0034] In accordance with an exemplary embodiment, the service unit 37 in the HEU 12 can include an RF signal modulator/demodulator unit 40 for modulating/demodulating the downlink electrical RF signals 18D and the uplink electrical RF signals 18U, respectively. The service unit 37 can include a digital signal processing unit ("digital signal processor") 42 for providing to the RF signal modulator/demodulator unit 40 an electrical signal that is modulated onto an RF carrier to generate a desired downlink electrical RF signal 18D. The digital signal processor 42 is also configured to process a demodulation signal provided by the demodulation of the uplink electrical RF signal 18U by the RF signal modulator/demodulator unit 40. The HEU 12 can also include an optional central processing unit (CPU) 44 for processing data and otherwise performing logic and computing operations, and a memory unit 46 for storing data, such as data to be transmitted over a WLA or other network for example.

[0035] With continuing reference to FIG. 2, the RAU 14 also includes a converter pair 48 comprising the O-E converter 30 and the E-0 converter 34. The O-E converter 30 converts the received downlink optical RF signals 22D from the HEU 12 back into downlink electrical RF signals SOD. The E-0 converter 34 converts uplink electrical RF signals SOU received from the client device 24 into the uplink optical RF signals 22U to be communicated to the HEU 12. The O-E converter 30 and the E-0 converter 34 are electrically coupled to the antenna 32 via an RF signal-directing element 52, such as a circulator for example. The RF signal-directing element 52 serves to direct the downlink electrical RF signals SOD and the uplink electrical RF signals SOU, as discussed below. In accordance with an exemplary embodiment, the antenna 32 can include one or more patch antennas, such as disclosed in U.S. Patent Application Serial. No. 11/504,999, filed August 16, 2006 entitled "Radio-over-Fiber Transponder With A Dual-Band Patch Antenna System," and U.S. Patent Application Serial No. 11/451,553, filed June 12, 2006 entitled "Centralized Optical Fiber-based Wireless Picocellular Systems and Methods," both of which are incorporated herein by reference in their entireties.

[0036] With continuing reference to FIG. 2, the optical fiber-based distributed communications system 10 also includes a power supply 54 that generates an electrical power signal 56. The power supply 54 is electrically coupled to the HEU 12 for powering the power-consuming elements therein. In an exemplary embodiment, an electrical power line 58 runs through the HEU 12 and over to the RAU 14 to power the O-E converter 30 and the E-0 converter 34 in the converter pair 48, the optional RF signal-directing element 52 (unless the RF signal- directing element 52 is a passive device such as a circulator for example), and any other power-consuming elements provided. In an exemplary embodiment, the electrical power line 58 includes two wires 60 and 62 that carry a single voltage and that are electrically coupled to a DC power converter 64 at the RAU 14. The DC power converter 64 is electrically coupled to the O-E converter 30 and the E-0 converter 34 in the converter pair 48, and changes the voltage or levels of the electrical power signal 56 to the power level(s) required by the power-consuming components in the RAU 14. In an exemplary embodiment, the DC power converter 64 is either a DC/DC power converter or an AC/DC power converter, depending on the type of electrical power signal 56 carried by the electrical power line 58. In another example embodiment, the electrical power line 58 (dashed line) runs directly from the power supply 54 to the RAU 14 rather than from or through the HEU 12. In another example embodiment, the electrical power line 58 includes more than two wires and carries multiple voltages.

[0037] To provide further exemplary illustration of how an optical fiber-based distributed communications system can be deployed indoors, FIG. 3 is provided. FIG. 3 is a partially schematic cut-away diagram of a building infrastructure 70 employing an optical fiber-based distributed communications system. The system may be the optical fiber-based distributed communications system 10 of FIGS. 1 and 2. The building infrastructure 70 generally represents any type of building in which the optical fiber- based distributed communications system 10 can be deployed. As previously discussed with regard to FIGS. 1 and 2, the optical fiber-based distributed communications system 10 incorporates the HEU 12 to provide various types of communication services to coverage areas within the building infrastructure 70, as an example. For example, as discussed in more detail below, the optical fiber-based distributed communications system 10 in this embodiment is configured to receive wireless RF signals and convert the RF signals into RoF signals to be communicated over the optical fiber 16 to multiple RAUs 14. The optical fiber-based distributed communications system 10 in this embodiment can be, for example, an indoor distributed antenna system (IDAS) to provide wireless service inside the building infrastructure 70. These wireless signals can include cellular service, wireless services such as RFID tracking, Wireless Fidelity (WiFi), local area network (LAN), WLAN, and combinations thereof, as examples.

[0038] With continuing reference to FIG. 3, the building infrastructure 70 in this embodiment includes a first (ground) floor 72, a second floor 74, and a third floor 76. The floors 72, 74, 76 are serviced by the HEU 12 through a main distribution frame 78 to provide antenna coverage areas 80 in the building infrastructure 70. Only the ceilings of the floors 72, 74, 76 are shown in FIG. 3 for simplicity of illustration. In the example embodiment, a main cable 82 has a number of different sections that facilitate the placement of a large number of RAUs 14 in the building infrastructure 70. Each RAU 14 in turn services its own coverage area in the antenna coverage areas 80. The main cable 82 can include, for example, a riser cable 84 that carries all of the downlink and uplink optical fibers 16D, 16U to and from the HEU 12. The riser cable 84 may be routed through an interconnect unit (ICU) 85. The ICU 85 may be provided as part of or separate from the power supply 54 in FIG. 2. The ICU 85 may also be configured to provide power to the RAUs 14 via the electrical power line 58, as illustrated in FIG. 2 and discussed above, provided inside an array cable 87 and distributed with the downlink and uplink optical fibers 16D, 16U to the RAUs 14. The main cable 82 can include one or more multi-cable (MC) connectors adapted to connect select downlink and uplink optical fibers 16D, 16U, along with an electrical power line, to a number of optical fiber cables 86.

[0039] The main cable 82 enables multiple optical fiber cables 86 to be distributed throughout the building infrastructure 70 (e.g., fixed to the ceilings or other support surfaces of each floor 72, 74, 76) to provide the antenna coverage areas 80 for the first, second and third floors 72, 74 and 76. In an example embodiment, the HEU 12 is located within the building infrastructure 70 (e.g., in a closet or control room), while in another example embodiment the HEU 12 may be located outside of the building infrastructure 70 at a remote location. A base transceiver station (BTS) 88, which may be provided by a second party such as a cellular service provider, is connected to the HEU 12, and can be co-located or located remotely from the HEU 12. A BTS is any station or source that provides an input signal to the HEU 12 and can receive a return signal from the HEU 12. In a typical cellular system, for example, a plurality of BTSs are deployed at a plurality of remote locations to provide wireless telephone coverage. Each BTS serves a corresponding cell and when a mobile station enters the cell, the BTS communicates with the mobile station. Each BTS can include at least one radio transceiver for enabling communication with one or more subscriber units operating within the associated cell.

[0040] The optical fiber-based distributed communications system 10 in FIGS. 1-3 and described above provides point-to-point communications between the HEU 12 and the RAU 14. Each RAU 14 communicates with the HEU 12 over a distinct downlink and uplink optical fiber pair to provide the point-to-point communications. Whenever an RAU 14 is installed in the optical fiber-based distributed communications system 10, the RAU 14 is connected to a distinct downlink and uplink optical fiber pair connected to the HEU 12. The downlink and uplink optical fibers may be provided in the optical fiber 16. Multiple downlink and uplink optical fiber pairs can be provided in a fiber optic cable to service multiple RAUs 14 from a common fiber optic cable. For example, with reference to FIG. 3, RAUs 14 installed on a given floor 72, 74, or 76 may be serviced from the same optical fiber 16. In this regard, the optical fiber 16 may have multiple nodes where distinct downlink and uplink optical fiber pairs can be connected to a given RAU 14.

[0041] It may be desirable to provide an optical fiber-based distributed communications system that can support a wide variety of radio sources. For example, it may be desired to provide an optical fiber-based distributed communications system that can support various radio types and sources, including but not limited to Long Term Evolution (LTE), US Cellular (CELL), Global System for Mobile Communications (GSM), Code Division Multiple Access (CDMA), Time Division Multiple Access (TDMA), Advanced Wireless Services (AWS), iDEN (e.g., 800 MegaHertz (MHz), 900 MHz, and 1.5 GigaHertz (GHz)), etc. These radio sources can range from 400 MHz to 2700 MHz as an example. To support a radio source, the HEU must contain lasers that are capable of modulating the radio signal into optical RF signals at the frequency of the radio signal for transmission over optical fiber. Likewise, lasers must be provided to convert the optical RF signals back into electrical RF signals at the frequencies of the radio band supported. It is costly to provide different conversion lasers for all possible radio sources that may be desired to be supported by an optical fiber-based distributed communications system.

[0042] In this regard, in certain embodiments disclosed herein, optical fiber-based distributed communications systems are provided that support a wide range of radio sources. The optical fiber-based distributed communications systems disclosed herein also provide a variety of features. These features include, but are not limited to, the ability to distribute both RF communication services and digital data services over the optical fiber-based distributed communications systems. Flexibility is provided in the components of the optical fiber-based distributed communications systems to provide upgradability and other enhanced features. The optical fiber-based distributed communications systems disclosed herein also provide features that support scalability, upgradability, reliability, management, capacity, and enhanced coverage areas.

[0043] In this regard, FIG. 4 is a schematic diagram of another exemplary optical fiber-based distributed communications system 90. In this embodiment, the optical fiber- based distributed communications system 90 is comprised of three basic components. One or more RF interface modules (RIMs) 92(1)-92(N) are provided in a HEU 94 to receive and process downlink electrical RF signals 96(1)-96(N) prior to optical conversion into downlink optical RF signals. The processing of the downlink electrical RF signals 96(1)-96(N) can include any of the processing previously described above in the HEU 12 in FIG. 2. The "1-N" notation indicates that any number of the referenced component, 1-N, may be provided. As will be described in more detail below, the HEU 94 is configured to accept a plurality of RIMs 92 as modular components that can be easily installed and removed or replaced in the HEU 94. In one embodiment, the HEU 94 is configured to support up to four (4) RIMs 92 as an example. Each RIM 92 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 HEU 94 and optical fiber-based distributed communications system 90 to support the desired radio sources.

[0044] For example, one RIM 92 may be configured to support the Personal Communication Services (PCS) radio band. Another RIM 92 may be configured to support the Long Term Evolution (LTE) 700 radio band. In this example, by inclusion of these RIMs 92, the HEU 94 would be configured to support downlink electrical RF signals 96 and electrical uplink RF signals 112 on both PCS and LTE 700 radio bands. RIMs 92 may be provided in the HEU 94 that support any other radio bands desired, including but not limited to PCS, LTE, CELL, GSM, CDMA, CDMA2000, TDMA, AWS, iDEN (e.g., 800 MHz, 900 MHz, and 1.5 GHz), Enhanced Data GSM Environment, (EDGE), Evolution-Data Optimized (EV-DO), lxRTT (i.e., CDMA2000 IX (IS-2000)), High Speed Packet Access (HSPA), 3GGP1, 3GGP2, and Cellular Digital Packet Data (CDPD). More specific examples include, but are not limited to, radio bands between 400-2700 MHz including but not limited to 700 (LTE), 698-716 MHz, 728-757 MHz, 776-787 MHz, 806-824 MHz, 824-849 (US Cellular), 851-869 MHz, 869-894 (US Cellular), 880-915 (EU R), 925-960 (TTE), 1930-1990 (US PCS), 2110-2155 (US AWS), 925-960 (GSM 900), 1710-1755 MHz, 1850-1915 MHz, 1805-1880 (GSM 1800), 1920- 1995 MHz, and 2110-2170 (GSM 2100). The optical fiber-based distributed communications system 90 is capable of operating in the preceding bands on uplink as well.

[0045] The downlink electrical RF signals 96(1)-96(N) are provided to a plurality of optical interface modules (OIMs) 98(1)-98(N) to convert the downlink electrical RF signals 96(1)-96(N) into downlink optical signals 100(1)-100(N). The OIMs 98 may be configured to provide one or more optical interface cards (OICs) that contain O-E and E- O converters, as will be described in more detail below. The OIMs 98 support the radio bands that can be provided by the RIMs 92, including those previously described above. Thus, in this embodiment, the OIMs 98 may support a radio band range from 400 MHz to 2700 MHz, as an example, to avoid providing different types or models of OIM 98 support for narrower radio bands to support possibilities for different radio band supported RIMs 92 provided in the HEU 94. Further, as an example, the OIMs 98 may be optimized for sub bands within the 400 MHz to 2700 MHz frequency range, such as 400 - 700 MHz, 700 MHz - 1 GHz, 1 GHz - 1.6 GHz, and 1.6 GHz - 2.7 GHz, as examples.

[0046] The OIMs 98(1)-98(N) include E-0 converters to convert the downlink electrical RF signals 96(1)-96(N) to downlink optical signals 100(1)-100(N). The downlink optical signals 100(1)-100(N) are communicated over downlink optical fiber(s) 103D to a plurality of RAUs 102(1)-102(N). O-E converters in the RAUs 102(1)-102(N) convert the downlink optical signals 100(1)-100(N) back into downlink electrical RF signals 104(1)-104(N) that are transmitted over antennas 106(1)-106(N) to client devices in the transmission range of the antennas 106(1)-106(N). As will be described in more detail below, both RF communication signals and digital data signals or services may be provided as downlink optical signals 100(1)-100(N).

[0047] E-0 converters are also provided in the RAUs 102(1)-102(N) to convert uplink electrical RF signals received from client devices through the antennas 106(1)- 106(N) into uplink optical signals 108(1)-108(N) to be communicated over uplink optical fibers 103U to the OIMs 98(1)-98(N). The OIMs 98(1)-98(N) include O-E converters that convert the uplink optical signals 108(1)-108(N) into uplink electrical RF signals 110(1)-110(N) that are processed by the RIMs 92(1)-92(N) and provided as uplink electrical RF signals 112(1)-112(N). As will be described in more detail below, both RF communication signals and digital data signals or services may be provided as uplink optical signals 108(1)-108(N).

[0048] The HEU 94 may also include client device localization support, such as Emergency 911 (E911) support. For example, localization services can be provided as described in U.S. Provisional Patent Application Serial No. 61/319,659 filed on March 31, 2010 entitled "Localization Services In Optical Fiber-Based Distributed Communications Components And Systems, and Related Methods," incorporated herein by reference in its entirety.

[0049] FIG. 5 is a more detailed schematic diagram of the exemplary optical fiber- based distributed communications system 90 of FIG. 4. As illustrated therein, the HEU 94 can be provided in a HEU housing 113. A power supply 114 is provided in the HEU housing 113 configured to supply power to the power consuming components of the HEU 94. A plurality of RIMs 92(1)-92(N) are provided in the HEU 94 to receive the downlink electrical RF signals 96(1)-96(N) and provide the uplink electrical RF signals 112(1)- 112(N). The RIMs 92(1)-92(N) are configured to support particular radio sources or range of radio frequencies. The HEU housing 113 supports modularity of the RIMs 92(1)-92(N). In this regard, RIMs 92(1)-92(N) can be installed and removed as desired to allow the HEU 94 and optical fiber-based distributed communications system 90 to support the desired radio sources or ranges. A fan module 116 can also be included in the HEU 94 to provide cooling of the components in the HEU 94.

[0050] A head-end controller (HEC) 118 may also be included in the HEU 94. The HEC 118 may include a micro-controller(s) or microprocessor(s) to perform features, such as monitoring of the data communications, monitoring of various power levels and other data to determine if alarm conditions exists, to support remote access via a user interface, such as a graphical user interface (GUI). Examples of these features are described in International Application No. PCT/US 10/22847 filed on February 2, 2010 entitled "Optical Fiber-Based Distributed Antenna Systems, Components, and Related Methods For Monitoring and Configuring Thereof," incorporated herein by reference in its entirety.

[0051] As illustrated in FIG. 6, The RIMs 92(1)-92(N) are coupled to an RF routing module (RRM) 150 in this embodiment. The RRM 150 routes the downlink electrical RF signals 96(1)-96(N) after being processed by the RIMs 92(1)-92(N) to an appropriate OIC 120 provided in an OIM 98. The OIM 98 is this embodiment is configured to support up to three (3) OICs 120(1)-120(3). Each OIC 120 is configured to provide optical RF signals converted from downlink electrical RF signals 96 to a RAU 102. Each OIC 120 in this embodiment includes an E-0 converter and an O-E converter to convert downlink electrical RF signals 96 into downlink optical signals 100 to be provided to an RAU 102, and convert received uplink optical signals 108 into uplink electrical RF signals 112.

[0052] Digital data services may also be provided by the HEU 94. In this regard, the HEU 94 in FIG. 5 can include an integrated digital data services (DDS) switch module 122 that is configured to receive and convert electrical digital data signals into optical digital data signals over the downlink optical fiber 103D to be provided to the RAUs 102 to provide access to digital data services at the RAUs 102. In this regard, an access point (AP) 123 to provide access to the digital data services can be provided at an RAU 102. The integrated DDS switch module 122 is also configured to receive electrical digital signals from the AP 123 to be communicated over a network providing the digital data services to the integrated DDS switch module 122. Examples of digital data services include, but are not limited to, WLAN, WiMax, WiFi, Digital Subscriber Line (DSL), and LTE, etc. The digital data services may be provided over an Ethernet network as an example. For example, the integrated DDS switch module 122 may be an Ethernet service module (e.g., a 100 Megabit (MB) service). Other Ethernet standards that could be supported, include but are not limited to 100 Megabits per second (Mbs) (i.e., fast Ethernet) or Gigabit (Gb) Ethernet, or ten Gigabit (10G) Ethernet. Digital data service protocols, such as Simple Network Management Protocol (SNMP), may be supported.

[0053] More information about providing digital data services in an optical fiber- based distributed communications system is disclosed in U.S. Provisional Patent

Application Serial No. / , filed on May 2, 2010 and entitled, "Providing Digital

Data Services in Optical Fiber-based Distributed Radio Frequency (RF) Communication Services, and Related Components and Methods," incorporated herein by reference in its entirety.

[0054] The downlink and uplink optical fibers 103D, 103U from the OIMs 98 may be connected to a patch panel 124 and routed through one or more riser cables 126(1)- 126(N) to one or more ICUs 128(1)- 128(N). The ICUs 128(1)- 128(N) provide a common point in which the downlink and uplink optical fibers 103D, 103U can be bundled into one or more array cables 130(1)- 130(N) for providing RF communication services and/or digital data services to the RAUs 102. Any combination of services or types of optical fibers can be provided in the array cables 130(1)-130(N). For example, the array cables 130(1)-130(N) may include single mode and/or multi-mode optical fibers for RF communication services and/or digital data services. Digital data switch modules can also be provided in the ICU 128 as opposed to the HEU 94. For example, an external DDS switch module 132 may be included or provided at the ICU 128 to provide digital data services to RAUs 102 through optical fibers provided in the array cable 130. For example, the external DDS switch module 132 may support Ethernet, including but not limited to 100 Megabit (Mb), Gigabit (Gb) and 10 Gb services, as an example. Providing digital data services outside of the OIMs 98 via the external DDS switch module 132 may allow greater bandwidth digital data services to be provided if lasers in E-0 converters in the OIM 98 are not able to provide the bandwidth of such digital data services.

[0055] As illustrated in FIG. 5, some RAUs 102(1) are configured to provide digital data services via AP 123(1) from both DDS switch modules 122 and 132 as well as RF communication services. Other RAUs 102(2) may be configured to only provide digital data services via AP 123(2). Other RAUs 102(6), 102(30), 102(N) may be configured to only provide RF communication services.

[0056] FIG. 6 is a schematic diagram of the HEU 94 in FIG. 5 to provide more detail on exemplary components that can be provided in the HEU 94. As illustrated in FIG. 6, the RIM 92 may include an RF connector 134 to connect an RF cable to receive the downlink electrical RF signals 96 and provide the uplink electrical RF signals 112. The RF connector 134 may be a duplexed or unduplexed connector. The downlink electrical RF signals 96 are provided to an amplification/attenuation stage 136 in a downlink BTS module 138 to process and condition the downlink electrical RF signals 96 to the desired power level prior to conversion to optical RF signals in the OIM 98. As examples, the downlink input power to the RIMs 92 may be between -15 dB and 33 dB with a 43 dB maximum with gain settings adjustable based on the input power level of the radio source. As another example, the uplink input to the RIMs 92 may be in the range of -15 dB to -15 dB as an example. The RIM 92 may be configured to receive different types of radio sources, including but not limited to BTS, BDA, Digital Radio Head (DRH), and Picocell or Femtocells as examples.

[0057] To detect the power level of the downlink electrical RF signals 96, a power level detector 140 may also be provided in the downlink BTS module 138. The detected power levels may be provided to automatically adjust or calibrate the power level of the downlink electrical RF signal 96 or to report the power level to allow manual adjustment. Similarly, an uplink BTS module 142 is provided in the RIM 92 to process and condition the uplink electrical RF signals 112 from the OIMs 98. To detect the power level of the uplink electrical RF signals 112, a power level detector may 144 may also be provided in the uplink BTS module 142. The detected power levels may be provided to automatically adjust or calibrate the power level of the downlink electrical RF signals 96 or to report the power level of the uplink electrical RF signals 112 to allow manual adjustment. More information on calibration in an optical fiber-based distributed communications system is described in International Application No. PCT/US 10/22857, filed on February 2, 2010, entitled "Optical Fiber-Based Distributed Antenna Systems, Components, and Related Methods for Calibration Thereof," incorporated herein by reference in its entirety.

[0058] Downlink and uplink connectors 146, 148 are provided in the downlink BTS module 138 and uplink BTS module 142, respectively, to provide interfacing to the RRM 150. The RRM 150 in this embodiment includes a combiner 152 to combine downlink electrical signals 96 from multiple RIMs 92. The RRM 150 also contains a splitter 154 in this embodiment to split the downlink electrical signals 96 combined by combiner 152 to the plurality of OIMs 98 to be distributed to the RAUs 102. Similarly, the RRM 150 contains a combiner 156 to combine received uplink electrical signals from the individual OIMs 98 and then split via splitter 158 to the RIMs 92. Downlink and uplink connectors 160, 162 provide an interface between the OIMs 98 and the splitter 154 and the combiner 156, respectively.

[0059] FIG. 6 illustrates exemplary internal components of the OIM 98(1) in more detail. These components can be included in the other OIMs 98 in the HEU 94 as well. As illustrated in FIG. 6, the OIM 98(1) is configured to support three (3) RAUs 102 in this example. In this regard, three (3) E-0 converters 164 are provided to convert downlink electrical signals into downlink optical signals 166 to be provided to the RAUs 102. Three (3) O-E converters 168 are provided to convert uplink optical signals 170 from the RAUs 102 into uplink electrical signals. In this embodiment, the OIM 98(1) is also configured to provide digital data services (DDS) to the RAUs 102. In this regard, the DDS switch module 122D can be provided to provide downlink digital data services from a DDS module 127 receiving digital signals through a connector 125 to the RAUs 102. The DDS switch module 122D receives electrical digital data services from an outside source and provides the electrical digital data services to the E-0 converters 164 to convert the electrical digital data signals into optical digital signals. Thus, the lasers in the E-0 converters 164 to convert the downlink electrical RF signals 96 into downlink optical RF signals can also be used to convert the electrical digital signals into optical digital data signals. The downlink optical signals 166 can represent downlink optical RF signals and/or downlink optical digital signals. The DDS switch module 122U is also provided in the OIM 98(1) and receives uplink electrical digital signals from the RAUs 102 from the O-E converters 168.

[0060] FIG. 7 is a schematic diagram of exemplary internal components of the RAU 102 in FIG. 5. The RAU 102 may be provided as an electronics card, such as a printed circuit board (PCB), as an example. A power converter 179 may be included in the RAU 102 that receives and provides power to power consuming components of the RAU 102. The power provided to the power converter 179 may be sourced from the array cable 130 from the ICU 128, as illustrated in FIG. 5. As further illustrated in FIG. 7, the RAU 102 includes a downlink connector 180 that receives the downlink optical signal 166 and an uplink connector 182 that provides the uplink optical signal 170 to the OIM 98. Additional downlink and uplink ports 184, 186 may also be provided in the RAU 102. The downlink optical signal 166 is split via a splitter 188 into E-0 converters 190(1)- 190(N) to provide downlink electrical signals 192(1)-192(N), which are then multiplexed via multiplexer 194 to be provided to the antenna 106. The multiplexer 194 also allows the antenna 106 to receive uplink electrical signals 196 from client devices that are provided from the multiplexer 194 as uplink electrical signals 193(1)-193(N) to O-E converters 198(1)-198(N) into a combiner 200 and to the uplink connector 182 and uplink port 186.

[0061] A digital data port 202 is provided to provide access to downlink digital signals communicated to the RAU 102 from the OIM 98 via a cable 203 to the AP 123. As previously discussed, other digital data services can be provided to the RAU 102 that are not converted to optical digital signals in the OIM 98. For example, a DDS switch module 132 may be provided at the ICU 128. The RAU 102 may include a media converter 204 that converts downlink optical digital signals into downlink electrical digital signals to be accessed via downlink ports 206 to an AP 123 and handle received electrical data signals from the AP 123 via uplink port 208, as illustrated in FIG. 7. A power port 210 may also be provided to provide power to digital data service clients connected to the AP 123. For example, the power could comply with Power-over- Ethernet standards. The media converter 204 may be field installable into the RAU 102. Optional RF ports 212, 214 can also be provided for receiving additional filtering. [0062] Further, the RAU 102 may include downlink linear output power per frequency band supported. The RAU 102 may support filtering (e.g., IMD2, downlink/uplink, and out of band). The RAU 102 may support uplink SFDR optimization as an example. The RAU 102 may include broadband expansion ports, as previously described, for additional external RF modules. The RAU 102 may include downlink signal compensation for optical loss. Automatic gain control (AGC) may be provided for the uplink as needed (e.g., 20-25 dB range within 1 to 2 dB step). The RAU 102 may include an uplink/downlink pass band gain ripple within +/- 1.5 dB per radio band as an example. Final downlink power adjustment may be provided at levels within +/- 1 dB as an example.

[0063] FIG. 8 illustrates the building infrastructure 70 of FIG. 3, but with illustrative examples of digital data services and digital client devices that can be provided to client devices in addition to RF communication services in the optical fiber-based distributed communications system 90. As illustrated in FIG. 8, exemplary digital data services include WLAN 207, femtocells (e.g., 3G and 4G) 208, gateways 210, battery backup units (BBU) 212, remote radio heads (RRH) 214, and servers 216. Medical telemetry and building automation applications may be supported in the building infrastructure 70 as examples. More information regarding providing digital data services in an optical fiber- based distributed communications system and the RAU 102 is described in previously referenced U.S. Provisional Patent Application Serial No. / , filed on May 2,

2010 and entitled, "Providing Digital Data Services in Optical Fiber-based Distributed Radio Frequency (RF) Communication Services, and Related Components and Methods," which is incorporated herein by reference in its entirety.

[0064] The HEU 94 supports upgradability from Single Input/Single Output (SISO) to Multiple Input/Multiple Output (MIMO) communication schemes, if desired. In this regard, FIG. 9 is a schematic diagram of an exemplary MIMO communication scheme that can be employed in the optical fiber-based distributed communications systems 90 of FIGS. 4-8. By providing modularity in providing RIMs 92 as previously discussed, MIMO configurations can easily be configured in the HEU 94. As illustrated in FIG. 9, four (4) RIMs 92(l)-92(4) are provided in this example in the HEU 94 to provide the ability to handle four (4) different radio bands. One RIM 92 labeled "MIMO 1" is provided to support received and process downlink electrical RF signals 96(1). For instance, the radio band for downlink electrical RF signal 96(1) could be LTE 700 as an example. The other radio bands supported by the RIMs 92(2)-92(4) may be other radio bands.

[0065] The RIM 92 labeled "MIMO 2" is provided in the HEU 94 to receive and support downlink electrical RF signals 96(1) at the same radio band as supported by the RIM 92 labeled "MIMO 1." In this manner, the same downlink electrical RF signals 96(1) are provided to two OIMs 98(1), 98(2) in the HEU 94 to be provided to two different RAUs 102(1), 102(2). The RAU 102(1) receives downlink optical signals 100(1)-100(4) at four (4) radio bands. The RAU 102(2) receives downlink optical signal 100(1) at one (1) radio band that is the same radio band as downlink optical signal 100(1) received by the RAU 102(1). The RAUs 102(1), 102(2) may be co-located or closely located, such as eight (8) to fifteen (15) meters (m) apart as an example. In this manner, the RAUs 102(1), 102(2) can both communicate to client devices at the radio band of the downlink electrical signal 96(1) and receive uplink electrical signals from client devices that are converted into uplink optical signals 108(1) to allow for MIMO processing of uplink electrical RF signals 112(1) resulting from the RAUs 102(1), 102(2).

[0066] FIG. 10 provides an alternative MIMO communication configuration in the optical fiber-based distributed communications system 90 to the MIMO communication configuration provided in FIG. 9. As illustrated in FIG. 10, the two (2) RIMs 92 labeled "MIMO 1" and "MIMO 2" are provided just as provided in FIG. 9. However in FIG. 10, only one OIM 98(1) is illustrated for the MIMO communication configuration in this embodiment. In this embodiment, the OIM 98(1) receives the downlink electrical RF signals 96(l)-96(4) as provided in FIG. 9. The OIM 98(1) receives and converts the downlink electrical RF signals 96(l)-96(4) into downlink optical signals 100(1)-100(4) as also provided in FIG. 9. However, instead of providing the downlink optical signal 100(1) to a second OIM 98 as provided in FIG. 9, the downlink optical signals 100(1)- 100(4) are provided to the RAU 102(1). The RAU 102(1) provides the conversion of the downlink optical signal 100(1) to downlink electrical signals 219D provided to a communications module 220 that is not an RAU 102, but rather a transceiver with an antenna 222 that can communicate the received downlink optical signal 100(1) received from the RAU 102(1) to client devices. The communications module 220 is also configured to provide uplink electrical signals 219U from client devices via reception by antenna 222 to the RAU 102(1). Additional ports on the RAU 94 may be used in this regard. Uplink electrical signals from a client device in response to the downlink optical signal 100(1) can be returned by the RAU 102(1) to the HEU 94 for MIMO processing. The patch panel 124 can route the uplink electrical RF signals 112(1) to the RIMs 92 labeled "MIMO 1" and "MIMO 2" for MIMO processing.

[0067] The optical fiber-based distributed communications system 90 can also be deployed among multiple locations or buildings using multiple HEUs 94(1)-94(N). In this regard, FIG. 11 is a schematic diagram of exemplary multiple HEUs 94(1)-94(N) provided in multiple buildings 230(1)-230(N). The buildings 230(1)-230(N) each include an optical fiber-based distributed communications system 90(1)-90(N). To provide centralized control of the HEUs 94(1)-94(N), a main radio interface unit (RIU) 232 can be provided that is configured to provide uplink and downlink electrical signals 234(1)- 234(N), 236(1)-236(N) to a combining module 238. The combining module 238 is configured to combine the downlink electrical signals 234(1)-234(N) and provide the combined downlink electrical signals 234(1)-234(N) to converters 240(1)-240(N) connected to downlink optical fibers 242D(1)-242D(N) and uplink optical fibers 242U(1)-242U(2) that are routed to the HEUs 94(1)-94(N). Converters 244(1)-244(N) are provided to convert the downlink optical signals from the downlink optical fibers 242D(1)-242D(N) into downlink electrical signals 246(1)-246(N) to be input into the HEUs 94(1)-94(N). Thus, the transport of the downlink optical signals over the downlink optical fiber 242D is transparent to the HEUs 94(1)-94(N). The HEUs 94(1)-94(N) are also configured to provide uplink electrical signals 248(1)-248(N) to the converters 244(1)-244(N) to be communicated to the converters 240(1)-240(N) to be communicated to the main RIU 232. FIG. 12 is another schematic diagram of the RIU 232 provided to interface to multiple HEUs 94(1)-94(N) to provide a plurality of optical fiber-based distributed communications systems 90(1)-90(N).

[0068] Various configurations of providing multiple optical fiber-based distributed communications systems are possible with the optical fiber-based distributed communications systems 90 described above. For example, in one embodiment as illustrated in FIG. 13, multiple optical fiber-based distributed communications systems 90(1)-90(N) can be provided in the same facility 248, such as a building for example. A first operator 250(1) can provide downlink electrical RF signals 252(1) and receive uplink electrical RF signals 254(1) at a desired radio band(s) to an HEU 94(1) that is located in the same facility 248 as other HEUs 94(N) to provide radio services at such radio band(s). Other operators 250(N) can provide downlink electrical RF signals 252(N) and receive uplink electrical RF signals 254(N) at a desired radio band(s) to other HEUs 94(N) in the same facility to provide radio services at other radio band(s). [0069] FIG. 14 is a schematic diagram of the optical fiber-based distributed communications system 90 wherein multiple operators 250(1)-250(N) interfacing with multiple HEUs 94(1)-94(N) can share common cabling in the common facility 248. As illustrated in FIG. 14, the HEUs 94(1)-94(N) share a common riser cable 126 and common array cable 130. The RAUs 102(1) configured to receive RF signals from the first operator 250(1) are connected to optical fibers in the common array cable 130 connected to the first HEU 94(1). The RAUs 102(N) configured to receive RF signals from the other operators 250(N) are connected to optical fibers in the common array cable 130 connected to the other HEUs 94(N).

[0070] FIG. 15 is a schematic diagram of the optical fiber-based distributed communications system 90, wherein multiple operators 250(1)-250(N) interfacing with multiple HEUs 94(1)-94(N) can share common cabling and RAUs 102 in the common facility 248. As illustrated in FIG. 15, the HEUs 94(1)-94(N) share a common riser cable 126 and common array cable 130. The RAUs 102 are configured to receive RF signals from the operator 250(1)-250(N). The RAUs 102 contain multiple separate amplifiers 256(1)-256(N), each amplifier 256(1)-256(N) configured to be compatible with the radio bands of each operator 250(1)-250(N). FIG. 16 illustrates the optical fiber-based distributed communications system 90 of FIG. 15, but each RAU 102 contains a shared amplifier 258 for the multiple operators 250(1)-250(N) to support RF communications at the radio bands provided by the multiple operators 250(1)-250(N).

[0071] Other features are also possible with the optical fiber-based distributed communications systems and their components described herein. For example, the optical fiber-based wireless communications systems described herein can also support one-touch upgrade, if desired. One-touch upgrade enables service providers to add additional service bands by making all changes at a single point. The feature is enabled by the RAUs at the time of their installation. For example, assuming one or two frequencies are in use after the initial installation, adding a third (or fourth) radio band can be accomplished with a single visit. This can be accomplished by connecting the new RF source to the HEU and accessing an embedded graphical user interface (GUI) therein. The RAU(s) corresponding to the area where the new radio band is desired is selected, and the new radio band is enabled by selecting it from the list of choices on the screen. The new radio band can now be delivered without requiring access to telecom closets or ceiling access, for example. [0072] Further, as used herein, it is intended that terms "fiber optic cables" and/or "optical fibers" include all types of single mode and multi-mode light waveguides, including one or more optical fibers that may be upcoated, colored, buffered, ribbonized and/or have other organizing or protective structure in a cable such as one or more tubes, strength members, jackets or the like. The optical fibers disclosed herein can be single mode or multi-mode optical fibers. Likewise, other types of suitable optical fibers include bend-insensitive optical fibers, or any other expedient of a medium for transmitting light signals. An example of a bend-insensitive, or bend resistant, optical fiber is ClearCurve^® Multimode fiber commercially available from Corning Incorporated. Suitable fibers of this type are disclosed, for example, in U.S. Patent Application Publication Nos. 2008/0166094 and 2009/0169163, the disclosures of which are incorporated herein by reference in their entireties.

[0073] Many modifications and other embodiments of the embodiments set forth herein will come to mind to one skilled in the art to which the embodiments pertain having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. Therefore, it is to be understood that the description and claims are not to be limited to the specific embodiments disclosed and that modifications and other embodiments are intended to be included within the scope of the appended claims. It is intended that the embodiments cover the modifications and variations of the embodiments provided they come within the scope of the appended claims and their equivalents. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.

Claims

What we claim is:

1. An apparatus configured to distribute radio -frequency (RF) communications signals in given radio bands in a distributed communications system, comprising:

a plurality of radio interface modules (RIMs) each configured to:

support a given radio band; and

distribute received downlink electrical RF communications signals at a frequency in the given radio band into a plurality of downlink electrical RF communications signals at the frequency in the given radio band to a plurality of remote antenna units (RAUs);

wherein at least two of the plurality of RIMs are configured to support different radio bands; and

a plurality of optical interfaces each configured to:

receive the plurality of downlink electrical RF communications signals from the plurality of RIMs; and

convert the received plurality of downlink electrical RF communications signals into a plurality of downlink optical RF communications signals.

2. The apparatus according to claim 1, wherein each of the plurality of optical interfaces is further configured to provide the plurality of downlink optical RF communications signals to the plurality of RAUs.

3. The apparatus according to claims 1 or 2, further comprising a downlink distribution matrix configured to distribute the plurality of downlink electrical RF communications signals to the plurality of RAUs.

4. The apparatus according to claims 1, 2, or 3, wherein each of the plurality of RIMs is further configured to filter the received downlink electrical RF communications signals in the given radio band.

5. The apparatus according to claims 1, 2, 3, or 4, wherein each of the plurality of RIMs further comprises a plurality of attenuators configured to control a power level for the received downlink electrical RF communications signals.

6. The apparatus according to claims 1, 2, 3, 4, or 5, further comprising a controller configured to control distribution of the plurality of downlink electrical RF communications signals for each of the plurality of RIMs.

7. The apparatus according to claims 1, 2, 3, 4, 5, or 6, further comprising a controller configured to control distribution of the plurality of downlink optical RF communications signals to the plurality of RAUs.

8. The apparatus according to claims 1, 2, 3, 4, 5, 6, or 7, wherein:

each of the the plurality of optical interfaces is further configured to:

split a received uplink optical RF communications signal into a plurality of uplink optical RF communications signals;

convert the plurality of uplink optical RF communications signals into a plurality of uplink electrical RF communications signals; and control providing each of the split plurality of uplink optical RF communications signals to the plurality of RIMs; and

each of the plurality of RIMs is further configured to receive the plurality of uplink electrical RF communications signals from the plurality of optical interfaces.

9. The apparatus of claim 8, wherein each of the plurality of RIMs is further configured to provide the received plurality of uplink electrical RF communications signals to one or more carriers.

10. The apparatus according to claim 8, further comprising an uplink distribution matrix configured to distribute the plurality of uplink optical RF communications signals.

11. The apparatus according to claim 8, further comprising a controller configured to control providing the plurality of uplink electrical RF communications signals from the plurality of optical interfaces to the plurality of RIMs.

12. A method of distributing RF communications signals in given radio bands in a distributed communications system, comprising:

distributing received downlink electrical radio frequency (RF) communications signals at a plurality of frequencies in a plurality of given radio band in a plurality of radio interface module (RIM) supporting a given radio band, wherein at least two of the plurality of RIMs are configured to support different radio bands, into a plurality of downlink electrical RF communications signals at the frequency in the given radio band to a plurality of remote antenna units (RAUs);

receiving the plurality of downlink electrical RF communications signals from the plurality of RIMs in a plurality of optical interfaces; and

converting the received plurality of downlink electrical RF communications signals into a plurality of downlink optical RF communications signals in the plurality of optical interfaces.

13. The method according to claim 12, further comprising the plurality of optical interfaces providing the plurality of downlink optical RF communications signals to the plurality of RAUs.

14. The method according to claims 12 or 13, further comprising distributing the plurality of downlink electrical RF communications signals to the plurality of RAUs in downlink distribution matrix.

15. The method according to claims 12, 13, or 14, further comprising filtering the received downlink electrical RF communications signals in the given radio band in each of the plurality of RIMs.

16. The method according to claims 12, 13, 14, or 15, further comprising attenuating the power level for the received downlink electrical RF communications signals.

17. The method according to claims 12, 13, 14, 15, or 16, further comprising a controller controlling distribution of the plurality of downlink electrical RF communications signals for each of the plurality of RIMs.

18. The method according to claims 12, 13, 14, 15, 16, or 17, further comprising a controller controlling distribution of the plurality of downlink optical RF communications signals to the plurality of RAUs.

19. The method according to claims 12, 13, 14, 15, 16, 17 or 18, further comprising splitting a received uplink optical RF communications signal into a plurality of uplink optical RF communications signals in each of the plurality of optical interfaces; converting the plurality of uplink optical RF communications signals into a plurality of uplink electrical RF communications signals in each of the plurality of optical interfaces;

providing the uplink optical RF communications signals from the plurality of optical interfaces to the plurality of RIMs; and

receiving the plurality of uplink electrical RF communications signals from the plurality of optical interfaces in the plurality of RIMs.

20. The method of claim 19, further comprising providing the received plurality of uplink electrical RF communications signals from the plurality of RIMs to one or more carriers.

21. The method according to claims 19 or 20, distributing the plurality of uplink optical RF communications signals in an uplink distribution matrix.

22. The method according to claims 19, 20, or 21 further comprising a controller controlling providing the plurality of uplink electrical RF communications signals from the plurality of optical interfaces to the plurality of RIMs.