Patent Application
20140293894
The technology of the disclosure relates generally to distributing communications signals, and more particularly to distributing dynamically frequency-shifted intermediate frequency (IF) radio frequency (RF) communications signals, which may be used in distributed antenna systems (DASs).
No admission is made that any reference cited herein constitutes prior art. Applicant expressly reserves the right to challenge the accuracy and pertinence of any cited documents.
Wireless communications are rapidly growing, with ever-increasing demands for high-speed mobile data communications. As an example, local area wireless services (e.g., “wireless fidelity” or “WiFi” systems) and wide area wireless services are frequently deployed in many different areas (e.g., coffee shops, airports, libraries, etc.). Distributed communications or antenna systems communicate with wireless devices called “clients,” or “client devices”, which must reside within a wireless range or “cell coverage area” in order to communicate with an access point. Distributed antenna systems (DASs) are particularly useful when deployed in indoor environments where client devices may not otherwise be able to effectively receive radio frequency (RF) signals from a source such as a base station. Applications where DASs can be used to provide or enhance coverage for wireless services include public safety, cellular telephony, wireless local access networks (LANs), location tracking, and medical telemetry inside buildings and over campuses.
One approach to deploying a DAS involves the use of RF antenna coverage areas, also referred to as “antenna coverage areas.” Antenna coverage areas are formed by remotely distributed antenna units, also referred to as remote units (RUs). The RUs are configured to couple to one or more antennas configured to support the desired frequency(ies) or polarization to provide the antenna coverage areas. Antenna coverage areas can have a radius in a range from a few meters up to twenty meters. Combining a number of RUs 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 arrangement generates a uniform high quality signal enabling high throughput supporting the required capacity for users of the wireless system.
As the wireless industry evolves, DASs are becoming more sophisticated. DASs may require more complex electronic circuits to enable better use of limited bandwidths and to provide additional functionality. For example, electronic circuits may be employed for additional functionalities, such as interference reduction, increased output power, handling high dynamic range, and signal noise reduction. Further, the functionality of the RUs may be included in an (access point) AP in a distributed wireless communications system. It may be desired to provide the RUs' functionality in APs in a distributed wireless communications system without changing or enlarging the form factor of the APs.
In embodiments disclosed herein, a dynamic bandwidth control unit (DBCU) provides a plurality of intermediate frequency (IF) RF communications signals for distribution over a communications medium to one or more remote units (RUs) in a DAS. The DBCU is configured to instruct a frequency conversion controller to shift a frequency of each of a plurality of RF communications signals to non-overlapping intermediate frequencies (IFs). For at least one of the RF communications signals, the shifted IF is dynamically selected by the DBCU based on the frequency of at least one other RF communications signals. In this manner, the frequencies of the RF communications signals may be shifted to dynamically selected intermediate frequencies in order to optimize available bandwidth of communications media in the DAS. For example, by optimizing bandwidth usage in the available bandwidth, unused bandwidth between adjacent IF signals can be minimized, thereby increasing a total number of RF communications signals that can be transmitted over lower-bandwidth media, and maximizing the amount of remaining available bandwidth of the communications medium.
One embodiment relates to a DBCU for controlling frequency conversion of RF communications signals in a DAS. The DBCU is configured to identify a plurality of RF communications signals. The DBCU is further configured to sequentially assign an IF for each of the plurality of RF communications signals, wherein assigning at least one IF is based on a previously assigned IF. The DBCU is further configured to determine a plurality of mixing frequencies for converting the plurality of respective RF communications signals into the plurality of respective IF signals.
An additional embodiment relates to a method for controlling frequency conversion of RF communications signals in a DAS. The method comprises identifying a plurality of RF communications signals, sequentially assigning an IF for each of the plurality of RF communications signals, wherein assigning at least one IF is based on a previously assigned IF, and determining a plurality of mixing frequencies for converting the plurality of respective RF communications signals into the plurality of respective IF signals.
An additional embodiment relates to a DAS having a DBCU for controlling frequency conversion of RF communications signals. The DBCU is configured to identify a plurality of downlink RF communications signals, and to sequentially assign a downlink IF for each of the plurality of downlink RF communications signals, wherein assigning at least one downlink IF is based on a previously assigned downlink IF. The DBCU is further configured to determine a plurality of mixing frequencies for converting the plurality of respective downlink RF communications signals into the plurality of respective downlink IF signals, and to generate a management signal containing information regarding the downlink RF communications signals and the downlink IF signals. The DAS further includes a head-end unit (HEU) associated with the DBCU configured to transmit the plurality of downlink Ifs, and at least one RU. Each RU is configured to receive the plurality of downlink IFs and convert the plurality of downlink IFs to the plurality of downlink RF communications signals.
An additional embodiment relates to a non-transitory computer-readable medium comprising instructions for directing a processor to perform a method for controlling frequency conversion of RF communications signals in a DAS. The method comprises identifying a plurality of RF communications signals, and sequentially assigning an IF for each of the plurality of RF communications signals, wherein assigning at least one IF is based on a previously assigned IF. The method further comprises determining a plurality of mixing frequencies for converting the plurality of RF communications signals into a plurality of IF signals.
Additional features and advantages are 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. The foregoing general description and the following 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.
Before discussing the DCBU and related embodiments, a conventional wireless system is illustrated in
In wireless/cellular networks, such as the DAS 12 in
In many conventional DASs, such as the DAS 12 of
Many conventional DASs 12 are designed to simultaneously support multiple frequency bands (e.g. 700 MHz, 850 MHz, 1900 MHz). These DASs 12 usually transfer several active channels within each frequency band as well. The frequency bands are significantly wider than the actual required bandwidth for the transfer of the active channels at any given time. To transfer a complete band, the DAS 12 must support a frequency range equal to the sum of the supported frequency bands, as if the IF is using the entire frequency range (i.e., operating at maximum bandwidth) at all times. During periods of non-peak activity, a large portion of the bandwidth between bands is unused, and the usage profile of each band might also change over time. Thus, it can be seen that conventional IF shifting methods do not efficiently allocate bandwidth. This problem becomes particularly acute with relatively low bandwidth copper-based communications mediums 18.
According to one aspect of the present embodiments, bandwidth is optimized by identifying the existence, the location, and the bandwidth of the active channels, and by dynamically arranging those active channels in a way that minimizes the bandwidth used by the communications medium 18.
The distributed RF antenna system 12 is configured to create one or more antenna coverage areas 10 for establishing communications with wireless client devices 22 located in the RF range of the antenna coverage areas 10 created by RUs 14. The RUs 14 may also be termed “remote antenna units” if they contain one or more antennas to support wireless communications. The system 12 provides any type of RF communications services desired, for example cellular radio services as a non-limiting example. In this embodiment, the system 12 includes head-end equipment, such as the HEU 16, one or more RUs 14, and a communications medium 18 that communicatively couples the HEU 16 to the RU 14. The HEU 16 is configured to provide RF communication services to the RU 14 for wireless propagation to wireless client devices 22 in communication range of an antenna 20 of the RU 14. The RU 14 may also be configured to support wired communications services. Note that although only one RU 14 is illustrated as being communicatively coupled to the HEU 16 in
With continuing reference to
The RU 14 includes a communications interface 34 configured to receive downlink RF communications signals 36D (36D(1)-36D(4) in this example) and provide downlink RF communications signals 36D providing the RF communications services to an antenna interface 38. The antenna 20, which is electrically coupled to the antenna interface 38, is configured to wirelessly radiate the downlink RF communications signals 36D to wireless client devices 22 in wireless communication range of the antenna 20. The communications interface 34 could include a cable interface that interfaces with a cable medium (e.g., coaxial cable, fiber optic cable) for sending and receiving communications signals, including the downlink RF communications signals 36D.
In this embodiment, the HEU 16 also includes a dynamic bandwidth control unit (DBCU) 40 for shifting each of the “native” downlink RF communications signals 26D into respective “shifted” downlink RF signals 30D, also referred to herein as downlink IF signals 30D. In some embodiments, the downlink RF communications signals 26D are passed by the DBCU 40 and remain the same signals as the downlink RF communications signals 26D. In this embodiment, as provided in the distributed RF antenna system 12 of
To recover the downlink RF communications signals 26D at the RU 14 to be radiated by the antenna 20, an up converter circuitry (UC) 44 is provided in the RU 14 to up convert the downlink IF signals 30D to the downlink RF communications signals 36D. The downlink RF communications signals 36D are of the same or substantially the same frequency as the downlink RF communications signals 26D in this embodiment. The downlink RF communications signals 36D may be frequency locked to the downlink RF communications signals 26D. The downlink RF communications signals 36D may be phase locked to the downlink RF communications signals 26D, such as through a phase locked loop (PLL) circuit in a complementary UC 44, as another non-limiting example.
With continuing reference to
The uplink RF communications signals 36U are frequency shifted by DC 46 in the RU 14 to provide uplink IF signals 30U. The uplink RF communications signals 36U are down converted to the uplink IF signals 30U to an IF that is different from the frequency of uplink RF communications signals 36U. In this embodiment, as will be discussed in greater detail below, a channel identifier 48 disposed in the DBCU 40 generates a management signal 50 that controls the remote side UCs 44 and DCs 46. To recover the uplink RF communications signals 36U at the HEU 16 to be provided to the BTS 28, a UC 52 is provided in the HEU 16 to up convert the uplink IF signals 30U to the uplink RF communications signals 26U. In this embodiment, the uplink RF communications signals 26U are of the same or substantially the same frequency as the uplink RF communications signals 36U. The uplink RF communications signals 26U may be frequency locked to the uplink RF communications signals 36U. The signals 26U may be phase locked to the uplink RF communications signals 36U, such as through a PLL circuit in the UC 44, as another non-limiting example.
Although
The communications medium 18 in the distributed RF antenna system 12 could be any number of media. For example, the communications medium 18 may be an electrical conductor, such as twisted-pair wiring or coaxial cable. Frequency division multiplexing (FDM) or time division multiplexing (TDM) can be employed to provide RF communications signals between the HEU 16 and multiple RUs 14, which are communicatively coupled to the HEU 16 over the same communications medium 18. Alternatively, separate, dedicated communications medium 18 may be provided between each RU 14 and the HEU 16. The UCs 44, 52, and DCs 42, 46 in the RUs 14 and the HEU 16 could be provided to frequency shift at different IFs to allow RF communications signals from multiple RUs 14 to be provided over the same communications medium 18 without interference in RF communications signals (e.g., if different codes or channels are not employed to separate signals for different users).
Also, for example, the communications medium 18 may have a lower frequency handling rating than the frequency of the RF communications service. In this regard, the down conversion of the downlink and uplink RF communications signals 26D, 26U frequency shifts the signals to an IF that is within the frequency rating of the communications medium 18. The communications medium 18 may have a lower bandwidth rating than the bandwidth requirements of the RF communications services. Thus, again, the down conversion of the downlink and uplink RF communications signals 26D, 26U can frequency shift the signals to an IF that provides a bandwidth range within the bandwidth range of the communications medium 18. For example, the distributed RF antenna system 12 may be configured to use an existing communications medium 18 for other communications services, such as digital data services (e.g., WLAN services). For example, the communications medium 18 may be Category 5, 6, or 7 (i.e., CAT 5, CAT 6, CAT 7) conductor cable that is used for wired services, such as Ethernet-based LAN as a non-limiting example. In this example, down conversion ensures that the downlink and uplink RF communications signals 36D, 36U can be properly communicated over the communications medium 18 with acceptable signal attenuation.
Synthesizer circuits 54, 56 in the HEU 16 and the RU 14, respectively, provide RF reference signals for frequency conversion by the DCs 42, 46 and the UCs 44, 52. The synthesizer circuit 54 is provided in the DBCU 40 of the HEU 16 and is controlled via a synthesizer control signal 57 received from the channel identifier 48. The synthesizer circuit 54 in the HEU 16 provides one of more local oscillator (LO) signals 58 to the DC 42 for frequency shifting the downlink RF communications signals 26D to the downlink RF communications signals 36D at a different IF. The synthesizer circuit 54 also provides one of more LO signals 60 to the UC 52 for frequency shifting the uplink RF communications signals 36U from the IF to the frequency of the RF communications services to provide the uplink RF communications signals 26U.
In this embodiment, the DBCU 40 dynamically shifts the active downlink RF communications signals 26D to different IF signals 30D as needed, for example, to use a narrower portion of the total bandwidth of the communications medium 18. Each DBCU 40 includes a channel identifier 48 configured to detect the presence of each downlink RF communications signal 26D. The channel identifier 48 continuously scans the active bands of the distributed RF antenna system 12, for example, by detecting the downlink RF communications signals 26D being served to the radio interface 24. The channel identifier 48 also determines relevant properties of each downlink RF communications signal 26D, such as a center frequency and bandwidth of each downlink RF communications signal 26D. The channel identifier 48 then dynamically assigns a downlink IF signal 30D for each downlink RF communications signal 26D such that at least one downlink IF signal 30D is based on another of the selected downlink IF signals 30D. In this example, the DBCU 40 selects a first downlink IF signal 30D and sequentially assigns each subsequent downlink IF signal 30D based on the previous adjacent downlink IF signal 30D. In this manner, the downlink IF signals 30D can be “stacked”, i.e., arranged, as close to each other as possible without interfering with each other, within a relatively narrow portion of the total bandwidth of the communications medium 18.
Thus, in this example, the “native bandwidth” (i.e., rated capacity) of a given communications medium 18 is more fully utilized. The channel identifier 48 of the DBCU 40 dynamically changes the arrangement of the IF channels periodically or in real time, based on the channel identifier's 48 continuous monitoring of the active channels of the distributed RF antenna system 12. Thus, any change in service on one or more channels can be detected by the DBCU 40 and the plurality of downlink IF signals 30D can be dynamically rearranged in real time to optimize bandwidth usage on the communications medium 18. One advantage of this arrangement is that it is not required to pre-set or hard-wire the distributed RF antenna system 12 to a static channel configuration, which must be changed manually whenever there is a change in service from the service provider.
The channel identifier 48 also generates a management signal 50 that is transmitted to each RU 14. The management signal 50 instructs the synthesizer circuit 54 of each RU 14 to generate a plurality of LO signals 58 based on each selected IF signal 30D. Each LO signal 58 is then transmitted to a respective DC 42, where the LO signal 58 is mixed with the respective downlink RF communications signal 26D to generate downlink IF signal 30D. In this manner, each downlink RF communications signal 26D is downshifter into the downlink IF signal 30D selected by the channel identifier 48.
In one embodiment, the channel identifier 48 instructs the synthesizer circuits 54 and/or 56 based on a lookup table (not shown). The lookup table can include all possible combinations of downlink RF communications signals 26D for a given hardware configuration of the system 12. When the channel identifier 48 identifies the configuration of downlink RF communications signals 26D, the channel identifier 48 then selects a predetermined configuration for the plurality of downlink IF signals 30D from the lookup table. As the configuration of downlink RF communications signals 26D changes over time, the channel identifier 48 dynamically updates the location and arrangement for the plurality of downlink IF signals 30D from the lookup table in real time.
In this embodiment, the management signal 50 also instructs the synthesizer circuit 56 to downshift the corresponding uplink RF communications signals 26U to the same uplink IF signals 30U as the corresponding downlink IF signals 30D. The synthesizer circuit 54 can then upshift each uplink IF signal 30U back to respective uplink RF communications signals 26U that are the same as the “native” uplink RF communications signals 36U, and that correspond to the “native” downlink RF communications signals 26D.
As one example, the LO signals 58, 60 generated by synthesizer circuit 56 may be directly provided to mixers in the DC 42 and UC 52 to control generation of mixing RF signals (not shown) to be mixed with the downlink RF communications signals 26D and the uplink RF communications signals 36U, respectively, for frequency shifting. The LO signals 58, 60 may be provided to control other circuitry that provides signals to control the mixers in the DC 42 and the UC 52. Oscillators (not shown) in the DC 42 and the UC 52 generate mixing RF signals to be mixed with the downlink RF communications signals 26D and the uplink RF communications signals 36U, respectively, for frequency shifting.
The synthesizer circuit 56 in the RU 14 provides one or more LO signals 62 to the DC 46 for frequency shifting the uplink RF communications signals 36U to the uplink RF communications signals 36U at a different IF. The synthesizer circuit 56 also provides one or more LO signals 64 to the UC 44 for frequency shifting the downlink RF communications signals 36D from the IF to the frequency of the RF communications services to provide the uplink RF communications signals 36U. As a non-limiting example, the LO signals 62, 64 are directly provided to mixers in the DC 46 and UC 44 to control generation of mixing RF signals (not shown) to be mixed with the downlink RF communications signals 36D and the uplink RF communications signals 36U, respectively, for frequency shifting. As another non-limiting example, the LO signals 62, 64 are not provided directly to mixers in the DC 46 and UC 44. The LO signals 62, 64 may be provided to control other circuitry that provides signals to control the mixers in the DC 46 and the UC 44. The oscillators in the synthesizer circuit 56 and the UC 44 generate mixing RF signals to be mixed with the downlink RF communications signals 36D and the uplink RF communications signals 36U, respectively, for frequency shifting.
The HEU 16 may be configured to support any frequencies desired, including but not limited to US FCC and Industry Canada frequencies (824-849 MHz on uplink and 869-894 MHz on downlink), US FCC and Industry Canada frequencies (1850-1915 MHz on uplink and 1930-1995 MHz on downlink), US FCC and Industry Canada frequencies (1710-1755 MHz on uplink and 2110-2155 MHz on downlink), US FCC frequencies (698-716 MHz and 776-787 MHz on uplink and 728-746 MHz on downlink), EU R & 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), medical telemetry frequencies, and WLAN frequencies. Further, the HEU 16 may be configured to support frequency division duplexing (FDD) and time divisional duplexing (TDD).
An exemplary RU 14 may be configured to support up to four (4) different radio bands/carriers (e.g. ATT, VZW, TMobile, Metro PCS: 700LTE/850/1900/2100). Radio band upgrades can be supported by adding remote expansion units over the same communications medium 18 (or upgrade to multiple-in/multiple-out (MIMO) on any single band). The RUs 14 and/or remote expansion units may be configured to provide external filter interface to mitigate potential strong interference at 700 MHz band (Public Safety, CH51,56); Single Antenna Port (N-type) provides DL output power per band (Low bands (<1 GHz): 14 dBm, High bands (>1 GHz): 15 dBm); and satisfies the UL System RF spec (UL Noise Figure: 12 dB, UL IIP3: −5 dBm, UL AGC: 25 dB range).
Channel identifier 48 can be implemented by appropriate hardware and/or software. In this regard,
The output of the mixer 66 produces an IF signal IF=±RF±LO. The specific IF frequency is determined by the center frequency of a band pass filter 70. The IF signal is next filtered by the band pass filter 70 and is then fed to a power detector 72. The power detector 72 determines the power level of the detected signal. This determined power level is then provided in analog form to an analog-to-digital converter (ADC) 74, which translates the analog power level to a digital format and provides it to a micro-controller 76.
The micro-controller 76 accumulates data from the RF frequency bands, including the frequency and the bandwidth of each active channel. Based on this data, the micro-controller 76 determines the frequency shift required by each DC 42 and provides this data to synthesizer circuit 54 via synthesizer control signal 47. In some embodiments, all the information required to produce the downlink IF signals 30D is contained in the synthesizer control signal 47 and is provided to the DCs 42 by the synthesizer circuit 54 as part of or alongside the LO signal 58. An additional filter management signal 77 can be provided from the channel identifier 48 directly to the DCs 42 to further control components of the DCs 42 such as filters, amplifiers, and other components of the DCs 42.
The information on the frequency shift and the bandwidth of the RF channel is transferred to the synthesizer circuits 56 of the RUs 14 via the management signal 50, where the IF band channels are up converted by UCs 44. The channel identifier 48 and management signal 50 can also adjust the uplink DCs 46 and UCs 52 accordingly as well.
In this example, a buffer band 92(1) of 100 kilohertz (kHz) is located at the lower boundary 84 of the 8 MHz band 80 of the communications medium 18, and the center frequency 90(1) of the IF signal 78(1) is selected to be fmin+725 kHz, where fmin is the lower boundary 84 of the 8 MHz band 80, such that the bandwidth of the IF signal 78(1) abuts the buffer band 92(1). The center frequency 90(2) of IF signal 78(2) is then selected such that the IF signal 78(2) abuts another buffer band 92(2) between IF signals 78(1) and 78(2). The center frequency 90(3) of IF signal 78(3) is selected such that the IF signal 78(3) abuts buffer band 92(3) between IF signals 78(2) and 78(3), and so on. Accordingly, the center frequencies 90 of IF signals 78 are arranged such that the IF signals 78 and buffer bands 92 are contained within a 6.25 MHz portion of the 8 MHz band 80, leaving a single unused portion 88 of the 8 MHz band 80 of 2.75 MHz. Thus, an additional 1.25 MHz channel can be transmitted within the 8 MHz band 80 of communications medium 18 without interfering with the other IF signals 78.
The channel identifier 48 can dynamically calculate a center frequency 82, 90 for each IF signal 78, based on the total bandwidth available, the location and bandwidth of each channel, and on the desired spacing between adjacent channels. In this example, the calculation of each center frequency fc is be represented by Equations 1-4 below:
f
c(1)=fmin+fbuffer+fb(1)/2 Equation 1:
f
c(2)=fc(1)+fb(1)/2+fbuffer+fb(2)/2 Equation 2:
f
c(3)=fc(2)+fb(2)/2+fbuffer+fb(3)/2 Equation 3:
f
c(4)=fc(3)+fb(3)/2+fbuffer+fb(4)/2 Equation 4:
In the above Equations 1-4, fmin is the lower boundary 84 of the 8 MHz band 80, fbuffer is the predetermined buffer band 92 bandwidth, fb(N) is the bandwidth of a given IF signal 78(N), and fc(N) is the center frequency 82, 90 of a given IF signal 78(N). It is also possible to vary any number of parameters as needed. For example, when more bandwidth is needed, the bandwidth of one or more buffer bands 92 can be dynamically reduced. On the other hand, if it is determined that two or more IF signals 78 are interfering with each other, the bandwidth of one or more buffer frequencies can be dynamically increased. In this manner, the full bandwidth of any given communications medium 18 can be utilized.
It may be desirable to provide both digital data services and RF communications services for wireless client devices in a DAS that employs an automatic antenna selection arrangement for providing both types of services simultaneously. Examples of digital data services include, but are not limited to, Ethernet, WLAN, WiMax, WiFi, Digital Subscriber Line (DSL), and LTE, etc. Ethernet standards could be supported, including but not limited to 100 Megabits per second (Mbs) (i.e., fast Ethernet) or Gigabit (Gb) Ethernet, or ten Gigabit (10G) Ethernet. Examples of digital data devices include, but are not limited to, wired and wireless servers, wireless access points (WAPs), gateways, desktop computers, hubs, switches, remote radio heads (RRHs), baseband units (BBUs), and femtocells. A separate digital data services network can be provided to provide digital data services.
In this regard,
With continuing reference to
Any of the DAS components disclosed herein can include a computer system.
The processing device 126 represents one or more general-purpose processing devices such as a microprocessor, central processing unit, or the like. More particularly, the processing device 126 may be a complex instruction set computing (CISC) microprocessor, a reduced instruction set computing (RISC) microprocessor, a very long instruction word (VLIW) microprocessor, a processor implementing other instruction sets, or processors implementing a combination of instruction sets. The processing device 126 is configured to execute processing logic in instructions 134 (located in the processing device 126 and/or the main memory 128) for performing the operations and steps discussed herein.
The computer system 124 may further include a network interface device 136. The computer system 124 also may include an input 138 to receive input and selections to be communicated to the computer system 124 when executing instructions. The computer system 124 also may include an output 140, including but not limited to a display, a video display unit (e.g., a liquid crystal display (LCD) or a cathode ray tube (CRT)), an alphanumeric input device (e.g., a keyboard), and/or a cursor control device (e.g., a mouse).
The computer system 124 may include a data storage device 142 that includes instructions 144 stored in a computer-readable medium 146. The instructions 144 may also reside, completely or at least partially, within the main memory 128 and/or within the processing device 126 during execution thereof by the computer system 124, the main memory 128 and the processing device 126 also constituting the computer-readable medium 146. The instructions 134, 144 may further be transmitted or received over a network 148 via the network interface device 136.
While the computer-readable medium 146 is shown in an exemplary embodiment to be a single medium, the term “computer-readable medium” should be taken to include a single medium or multiple media (e.g., a centralized or distributed database, and/or associated caches and servers). The term “computer-readable medium” shall also include any medium that is capable of storing, encoding or carrying a set of instructions for execution by the processing device and that cause the processing device to perform any one or more of the methodologies of the embodiments disclosed herein. The term “computer-readable medium” shall accordingly be taken to include solid-state memories, optical and magnetic medium, and carrier wave signals.
The embodiments disclosed herein include various steps that may be performed by hardware components or embodied in machine-executable instructions, which may be used to cause a general-purpose or special-purpose processor programmed with the instructions to perform the steps. Alternatively, the steps may be performed by a combination of hardware and software.
The embodiments disclosed herein may be provided as a computer program product, or software, that may include a machine-readable medium (or computer-readable medium) having stored thereon instructions, which may be used to program a computer system (or other electronic devices) to perform a process according to the embodiments disclosed herein. A machine-readable medium includes any mechanism for storing or transmitting information in a form readable by a machine (e.g., a computer). For example, a machine-readable medium includes a machine-readable storage medium (e.g., read only memory (“ROM”), random access memory (“RAM”), magnetic disk storage medium, optical storage medium, flash memory devices, etc.).
The various illustrative logical blocks, modules, and circuits described in connection with the embodiments disclosed herein may be implemented or performed with a processor, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A controller may be a processor. A processor may be a microprocessor, but in the alternative, the processor may be any conventional processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.
The embodiments disclosed herein may be embodied in hardware and in instructions that are stored in hardware, and may reside, for example, in Random Access Memory (RAM), flash memory, Read Only Memory (ROM), Electrically Programmable ROM (EPROM), Electrically Erasable Programmable ROM (EEPROM), registers, a hard disk, a removable disk, a CD-ROM, or any other form of computer-readable medium known in the art. An exemplary storage medium is coupled to the processor such that the processor can read information from, and write information to, the storage medium. In the alternative, the storage medium may be integral to the processor. The processor and the storage medium may reside in an ASIC. The ASIC may reside in a remote station. In the alternative, the processor and the storage medium may reside as discrete components in a remote station, base station, or server.
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.
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.
This application claims the benefit of priority under 35 U.S.C. §119 of U.S. Provisional Application No. 61/806,134, filed on Mar. 28, 2013, the content of which is relied upon and incorporated herein by reference in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| 61806134 | Mar 2013 | US |
