Patent Application
20160087745
The disclosure relates generally to distribution of data (e.g., digital data services and radio-frequency communications services) in a distributed antenna system (DAS) and more particularly to supporting an add-on remote unit(s) (RU) for new or additional communications services over an existing optical fiber communications medium using wavelength division multiplexing (WDM).
Wireless customers are demanding digital data services, such as streaming video signals. Concurrently, some wireless customers use their wireless devices in areas that are poorly served 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 distributed antenna systems (DASs). DASs can be particularly useful to be deployed inside buildings or other indoor environments where client devices may not otherwise be able to effectively receive radio-frequency (RF) signals from a source. DASs include remote units (also referred to as “remote antenna units”) configured to receive and wirelessly transmit wireless communications signals to client devices in antenna range of the remote units. Such DASs may use Wireless Fidelity (WiFi) or wireless local area networks (WLANs), as examples, to provide digital data services.
A typical DAS comprises head end equipment (HEE) communicatively coupled to a plurality of remote units (RUs). The HEE connects to a variety of wireless services, such as wideband code division multiple access (WCDMA), long term evolution (LTE), and WLAN communications services. A plurality of RUs is deployed inside buildings or other indoor environments to form RF antenna coverage areas. Each of the RUs contain or is configured to couple to one or more antennas configured to support desired frequency(ies) or polarization to redistribute the variety of wireless services to client devices in the respective RF antenna coverage area. The DAS may employ optical fiber as an optical fiber-based DAS to support reliable downlink distribution of the variety of wireless communications services from the HEE to the RUs and vice versa for uplink distribution. Each RU is communicatively coupled to the HEE through an optical fiber pair—one downlink optical fiber provided for downlink communications and one uplink optical fiber provided for uplink communications. Optical fiber enjoys the benefit of large bandwidth capability with low noise over conductor-based communications medium. However, fast advancement of wireless technologies and growing user demand for new or additional wireless communications services may exceed the capabilities of the existing, installed RUs in the optical fiber-based DAS even if the installed optical fiber communications medium has additional bandwidth availability to support such new or additional wireless communications services. As a result, new RUs may need to be added to the installed optical-fiber based DAS, but additional optical fiber must be provided to provide optical communications between the new RUs and the HEE.
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.
Embodiments disclosed in the detailed description include supporting an add-on remote unit(s) (RU) in an optical fiber-based distributed antenna system (DAS) over existing optical fiber communications medium using wavelength division multiplexing (WDM). An existing DAS comprises at least one existing head end equipment (HEE) communicatively coupled to a plurality of existing RUs through an optical fiber communication medium. The HEE is configured to distribute downlink communications signals over existing downlink optical fiber to the plurality of existing RUs. The plurality of RUs is configured to distribute uplink communications signals over existing uplink optical fiber to the HEE. In aspects disclosed herein, an add-on RU is added to the existing DAS to support additional wireless communications. No new optical fibers are required to be deployed to support communications to the add-on RU in the DAS. Instead, the DAS is configured to support the add-on RU through the existing optical fiber communications medium using WDM. By supporting the add-on RU in the DAS over the existing optical fiber communications medium supporting the existing RUs using WDM, the add-on RU can be added to the existing DAS without adding new optical fibers, thus leading to reduced service disruptions and deployment costs.
One embodiment of the disclosure relates to an upgraded HEE in an optical fiber-based DAS. The upgraded HEE comprises an existing downlink communications signal path, an add-on downlink communications signal path, and a HEE wavelength division multiplexer. The existing downlink communications signal path is configured to receive and convert at least one first downlink radio frequency (RF) communications signal into at least one first downlink optical signal. The add-on downlink communications signal path is configured to receive and convert at least one second downlink RF communications signal, which is different from the at least one first downlink RF communications signal, into at least one second downlink optical signal. The HEE wavelength division multiplexer is coupled to a downlink optical fiber. The HEE wavelength division multiplexer is configured to receive the at least one first downlink optical signal from the existing downlink communications signal path via at least one first downlink optical signal interface. The HEE wavelength division multiplexer is also configured to receive the at least one second downlink optical signal from the add-on downlink communications signal path via at least one second downlink optical signal interface. The HEE wavelength division multiplexer is also configured to wavelength division multiplex (WDM) the at least one first downlink optical signal and the at least one second downlink optical signal and generate a downlink WDM optical signal. The HEE wavelength division multiplexer is also configured to provide the downlink WDM optical signal to the downlink optical fiber coupled to a RU wavelength division de-multiplexer in at least one RU.
An additional embodiment of the disclosure relates to an upgraded RU system in an optical fiber-based DAS. The upgraded RU system comprises an existing RU downlink communications signal path. The existing RU downlink communications signal path is configured to receive and convert at least one first downlink optical signal into at least one first downlink electrical RF signal. The upgraded RU system also comprises an add-on RU downlink communications signal path. The add-on RU downlink communications signal path is configured to receive and convert at least one second downlink optical signal into at least one second downlink electrical RF signal, which is different from the at least one first downlink electrical RF signal. The upgraded RU system also comprises a RU wavelength division de-multiplexer. The RU wavelength division de-multiplexer is coupled to a downlink optical fiber. The RU wavelength division de-multiplexer is configured to receive a downlink wavelength division multiplexing (WDM) optical signal from the downlink optical fiber coupled to a HEE wavelength division multiplexer in at least one HEE. The RU wavelength division de-multiplexer is also configured to wavelength division de-multiplex the downlink WDM optical signal and generate the at least one first downlink optical signal and the at least one second downlink optical signal. The RU wavelength division de-multiplexer is also configured to provide the at least one first downlink optical signal to the existing RU downlink communications signal path via at least one first RU downlink optical signal interface. The RU wavelength division de-multiplexer is also configured to provide the at least one second downlink optical signal to the add-on RU downlink communications signal path via at least one second RU downlink optical signal interface.
An additional embodiment of the disclosure relates to an upgraded optical fiber-based DAS. The upgraded optical fiber-based DAS comprises a HEE, a RU system, at least one downlink optical fiber, and at least one uplink optical fiber. The HEE comprises at least one existing radio interface module (RIM), at least one existing optical interface module (OIM) coupled to the at least one existing RIM. The HEE also comprises at least one add-on RIM and at least one add-on OIM coupled to the at least one add-on RIM. The HEE also comprises a HEE wavelength division multiplexing/de-multiplexing (mux/demux) circuit coupled to the at least one existing OIM and the at least one add-on OIM. The HEE wavelength division mux/demux circuit further comprises a HEE wavelength division multiplexer and a HEE wavelength division de-multiplexer. The RU system comprises at least one existing RU, at least one add-on RU, and a RU wavelength division mux/demux circuit coupled to the at least one existing RU and the at least one add-on RU. The RU wavelength division mux/demux circuit further comprises a RU wavelength division multiplexer and a RU wavelength division de-multiplexer. The at least one downlink optical fiber connects the HEE wavelength division multiplexer to the RU wavelength division de-multiplexer. The at least one uplink optical fiber connects the RU wavelength division multiplexer to the HEE wavelength division de-multiplexer.
An additional embodiment of the disclosure relates to a method for adding an add-on RU in an existing DAS. The method comprises upgrading an existing RU system in the existing DAS. The method for upgrading an existing RU system in the existing DAS comprises providing an add-on RU. The add-on RU is configured to receive an add-on downlink wireless communications signal for an add-on wireless communications service over an existing downlink optical fiber coupled to an existing RU, wherein the existing RU is configured to receive an existing downlink wireless communications signal for an existing wireless communications service over the existing downlink optical fiber. The add-on RU is also configured to provide an add-on uplink wireless communications signal for the add-on wireless communications service over an existing uplink optical fiber coupled to the existing RU, wherein the existing RU is configured to provide an existing uplink wireless communications signal for the existing wireless communications service over the existing uplink optical fiber. The method for upgrading an existing RU system in the existing DAS further comprises disconnecting the existing downlink optical fiber and the existing uplink optical fiber from the existing RU, installing a RU wavelength division multiplexing/de-multiplexing (mux/demux) circuit, connecting the add-on RU and the existing RU to the RU wavelength division mux/demux circuit, and connecting the RU wavelength division mux/demux circuit to the existing downlink optical fiber and the existing uplink optical fiber. The method also comprises and upgrading an existing HEE in the existing DAS. The method for upgrading an existing HEE in the existing DAS comprises providing an add-on RIM. The add-on RIM is configured to receive the add-on downlink wireless communications signal from an add-on wireless communications service provider for the add-on wireless communications service. The add-on RIM is also configured to provide the add-on uplink wireless communications signal to the add-on wireless communications service provider for the add-on wireless communications service. The method for upgrading the existing HEE in the existing DAS further comprises providing an add-on OIM and connecting the add-on OIM to the add-on RIM. The method for upgrading the existing HEE in the existing DAS further comprises steps of identifying an existing OIM coupled to the existing downlink optical fiber and the existing uplink optical fiber, wherein the existing downlink optical fiber and the existing uplink optical fiber connect to the RU wavelength division mux/demux circuit. The method for upgrading the existing HEE in the existing DAS further comprises disconnecting the existing OIM from the existing downlink optical fiber and the existing uplink optical fiber, installing a HEE wavelength division mux/demux circuit, connecting the add-on OIM and the existing OIM to the HEE wavelength division mux/demux circuit, and connecting the HEE wavelength division mux/demux circuit to the existing downlink optical fiber and the existing uplink optical fiber.
Additional features will be set forth in the detailed description, 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, claims, and the drawings.
The foregoing general description and the detailed description are merely exemplary, and are intended to provide an overview to understand the nature and character of the claims. The accompanying drawings are included to provide a further understanding, and are incorporated in and constitute a part of this specification. The drawings illustrate one or more embodiment(s), and together with the description serve to explain principles and operation of the various embodiments.
Various embodiments will be further clarified by the following examples.
Embodiments disclosed in the detailed description include supporting an add-on remote unit(s) (RU) in an optical fiber-based distributed antenna system (DAS) over existing optical fiber communications medium using wavelength division multiplexing (WDM). An existing DAS comprises at least one existing head end equipment (HEE) communicatively coupled to a plurality of existing RUs through an optical fiber communication medium. The HEE is configured to distribute downlink communications signals over existing downlink optical fiber to the plurality of existing RUs. The plurality of RUs is configured to distribute uplink communications signals over existing uplink optical fiber to the HEE. In aspects disclosed herein, an add-on RU is added to the existing DAS to support additional wireless communications. No new optical fibers are required to be deployed to support communications to the add-on RU in the DAS. Instead, the DAS is configured to support the add-on RU through the existing optical fiber communications medium using WDM. By supporting the add-on RU in the DAS over the existing optical fiber communications medium supporting the existing RUs using WDM, the add-on RU can be added to the existing DAS without adding new optical fibers, thus leading to reduced service disruptions and deployment costs.
Before discussing aspects of supporting add-on RUs in an optical fiber-based DAS over existing optical fiber communication medium using WDM according to the present disclosure, a discussion of an exemplary existing optical fiber-based DAS that employs optical fiber communication medium to support wireless communications services to a plurality of RUs is first provided with references to
To illustrate specific aspects related to an optical fiber-based DAS,
Each RIM 32(1)-32(M) 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 HEE 34 and the optical fiber-based DAS 30 to support the desired radio sources. For example, one RIM 32 may be configured to support the Personal Communication Services (PCS) radio band. Another RIM 32 may be configured to support the 700 MHz radio band. In this example, by inclusion of these RIMs 32, the HEE 34 would be configured to support and distribute RF communications signals on both PCS and LTE 700 radio bands. RIMs 32 may be provided in the HEE 34 that support any 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). RIMs 32 may be provided in the HEE 34 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).
RIMs 32 may be provided in the HEE 34 that support any frequencies desired, including but not limited to US FCC and Industry Canada frequencies (824-849 MHz on uplink and 869-894 MHz on downlink), US FCC and Industry Canada frequencies (1850-1915 MHz on uplink and 1930-1995 MHz on downlink), US FCC and Industry Canada frequencies (1710-1755 MHz on uplink and 2110-2155 MHz on downlink), US FCC frequencies (698-716 MHz and 776-787 MHz on uplink and 728-746 MHz on downlink), EU R & TTE frequencies (880-915 MHz on uplink and 925-960 MHz on downlink), EU R & TTE frequencies (1710-1785 MHz on uplink and 1805-1880 MHz on downlink), EU R & 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).
The downlink electrical RF communications signals 36D(1)-36D(R) are provided to a plurality of optical interfaces provided in the form of optical interface modules (OIMs) 38(1)-38(N) in this embodiment to convert the downlink electrical RF communications signals 36D(1)-36D(R) into downlink optical RF communications signals 40D(1)-40D(R). The notation “1-N” indicates that any number of the referenced component 1-N may be provided. The OIMs 38 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 38 support the radio bands that can be provided by the RIMs 32, including the examples previously described above. Thus, in this embodiment, the OIMs 38 may support a radio band range from 400 MHz to 2700 MHz, as an example, so providing different types or models of OIMs 38 for narrower radio bands to support possibilities for different radio band-supported RIMs 32 provided in the HEE 34 is not required. Further, as an example, the OIMs 38 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.
The OIMs 38(1)-38(N) each include E/O converters (not shown) to convert the downlink electrical RF communications signals 36D(1)-36D(R) to downlink optical RF communications signals 40D(1)-40D(R). The downlink optical RF communications signals 40D(1)-40D(R) are communicated over downlink optical fiber(s) 43D to a plurality of remote units provided in the form of remote antenna units (RAUs) 42(1)-42(P). The notation “1-P” indicates that any number of the referenced component 1-P may be provided. O/E converters (not shown) provided in the RAUs 42(1)-42(P) convert the downlink optical RF communications signals 40D(1)-40D(R) back into downlink electrical RF communications signals 36D(1)-36D(R), which are provided over downlinks 44(1)-44(P) coupled to antennas 46(1)-46(P) in the RAUs 42(1)-42(P) to client devices 26 in the reception range of the antennas 46(1)-46(P).
E/O converters (not shown) are also provided in the RAUs 42(1)-42(P) to convert uplink electrical RF communications signals received from client devices 26 through the antennas 46(1)-46(P) into uplink optical RF communications signals 48U(1)-48U(R) to be communicated over uplink optical fibers 43U to the OIMs 38(1)-38(N). The OIMs 38(1)-38(N) include O/E converters (not shown) that convert the uplink optical RF communications signals 48U(1)-48U(R) into uplink electrical RF communications signals 50U(1)-50U(R) that are processed by the RIMs 32(1)-32(M) and provided as uplink electrical RF communications signals 52U(1)-52U(R).
Although the RU 64 in the DAS 60 in
In this regard,
In
In order to transmit both the existing downlink optical RF communications signal 102 and the add-on downlink optical RF communications signal 110 over an existing downlink optical fiber 112, a HEE multiplexing/de-multiplexing (mux/demux) circuit 114 is provided in the existing HEE 92. The HEE mux/demux circuit 114 wavelength division multiplexes the existing downlink optical RF communications signal 102 and the add-on downlink optical RF communications signal 110 into a downlink wavelength division multiplexing (WDM) optical signal 116. The downlink WDM optical signal 116 is communicated over the existing downlink optical fiber 112 to the existing RU system 94. In this manner, the existing downlink optical RF communications signal 102 and the add-on downlink optical RF communications signal 110 can be transmitted over the same downlink optical fiber.
With continuing reference to
For the uplink path, E/O converters (not shown) are also provided in the existing RU 120 and the add-on RU 122 to convert uplink electrical RF communications signals 99 and 107 received from client devices (not shown) through the at least one antenna (not shown) into an existing uplink optical RF communications signal 124 and an add-on uplink optical RF communications signal 126, respectively. The existing uplink optical RF communications signal 124 and the add-on uplink optical RF communications signal 126 are provided to a first RU uplink optical signal interface 125 and a second RU uplink optical signal interface 127, respectively. The existing uplink optical RF communications signal 124 and the add-on uplink optical RF communications signal 126 are wavelength division multiplexed by the RU mux/demux circuit 118 into an uplink WDM optical signal 128 and communicated over an existing uplink optical fiber 130 to the HEE mux/demux circuit 114. In this regard, the RU mux/demux circuit 118 and the existing RU 120 further provide an existing RU uplink communications signal path in the RU system 94. Similarly, the RU mux/demux circuit 118 and the add-on RU 122 further provide an add-on RU uplink communications signal path in the RU system 94. The HEE mux/demux circuit 114 wavelength division de-multiplexes the uplink WDM optical signal 128 into an existing uplink optical RF communications signal 124 and an add-on uplink optical RF communications signal 126. The existing uplink optical RF communications signal 124 is provided to at least one first uplink optical signal interface 131 and the add-on uplink optical RF communications signal 126 is provided to a second uplink optical signal interface 133. The existing OIM 98 includes O/E converters (not shown) that convert the existing uplink optical RF communications signal 124 into an existing uplink electrical RF communications signal 136. The existing uplink electrical RF communications signal 136 is provided to a first uplink electrical RF signal interface 132. The existing uplink electrical RF communications signal 136 is received and processed by the existing RIM 96 and provided as the existing uplink electrical RF communications signal 136 to the one or more wireless communications service providers (not shown). The add-on OIM 106 also includes O/E converters (not shown) that convert the add-on uplink optical RF communications signal 126 into an add-on uplink electrical RF communications signal 138. The add-on uplink electrical RF communications signal 138 is provided to at least one second uplink electrical RF signal interface 134. The add-on uplink electrical RF communications signal 138 is received and processed by the add-on RIM 104 and provided as the add-on uplink electrical RF communications signal 138 to the respective one or more wireless communications service providers (not shown). The existing OIM 98 and the existing RIM 96 provide an existing uplink communications signal path. Similarly, the add-on OIM 106 and the add-on RIM 104 provide an add-on uplink communications signal path By including the HEE mux/demux circuit 114 and the RU mux/demux circuit 118 in the existing HEE 92 and the existing RU system 94, respectively, the add-on RU 122 can be added to support add-on RF bands and/or wireless communications services without the need to deploy new optical fibers.
In this regard,
To illustrate the internal structure of the add-on RU 122 that shares the antenna 144 with the existing RU 120 shown in
As previously discussed in
To upgrade the optical fiber-based DAS 90 in
The DAS 90 in
Unless otherwise expressly stated, it is in no way intended that any method set forth herein be construed as requiring that its steps be performed in a specific order. Accordingly, where a method claim does not actually recite an order to be followed by its steps or it is not otherwise specifically stated in the claims or descriptions that the steps are to be limited to a specific order, it is no way intended that any particular order be inferred.
It will be apparent to those skilled in the art that various modifications and variations can be made without departing from the spirit or scope of the invention. Since modifications combinations, sub-combinations and variations of the disclosed embodiments incorporating the spirit and substance of the invention may occur to persons skilled in the art, the invention should be construed to include everything within the scope of the appended claims and their equivalents.
