1. Field of the Disclosure
The technology of the disclosure relates to location based systems for tracking locations of mobile terminals, including distributed antenna systems.
2. Technical Background
Wireless communication is rapidly growing, with ever-increasing demands for high-speed mobile data communication. As an example, 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 or antenna systems communicate with wireless devices called “clients,” “client devices,” or “wireless client devices,” which must reside within the wireless range or “cell coverage area” to communicate with an access point device. Distributed antenna systems are particularly useful to be deployed inside buildings or other indoor environments where client devices may not otherwise be able to effectively receive RF signals from a source.
One approach to deploying a distributed communications system involves the use of radio frequency (RF) antenna coverage areas. Antenna coverage areas can have a relatively short range from a few meters up to twenty meters. 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 bandwidth shared among the wireless system users. Use of optical fiber to distribute communication signals includes the benefit of increased bandwidth.
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 provides antenna coverage areas. The remote antenna units each include RF transceivers coupled to an antenna to transmit RF signals wirelessly, wherein the remote antenna units are coupled to the head-end station via optical fiber links. The RF transceivers in the remote antenna units are transparent to the RF signals. The remote antenna units convert incoming optical RF signals from the optical fiber link to electrical RF signals via optical-to-electrical (O/E) converters, which are then passed to the RF transceiver. The 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., 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 via electrical-to-optical (E/O) converters. The optical RF signals are then sent to the head-end station via the optical fiber link.
The remote antenna units can be distributed throughout locations inside a building to extend wireless communication coverage throughout the building. Other services may be negatively affected or not possible due to the indoor environment. For example, it may be desired or required to provide localization services for a client, such as emergency 911 (E911) services. If the client is located indoors, techniques such as global positioning services (GPS) may not be effective at providing or determining the location of the client. Further, triangulation techniques from the outside network may not be able to determine the location of the client.
Embodiments disclosed herein include location tracking for mobile terminals, related components, systems, and methods. For example, the systems disclosed herein can provide location information to mobile terminals that may not be able to receive otherwise global positioning system (GPS) information from the GPS satellites, such as, for example, when the mobile terminal does not receive GPS signals from the GPS satellites. Providing location information to clients inside a building or other location may make location based services, such as emergency (E911) services, for example, possible based on the location information.
In one embodiment, a distributed communications system comprises at least one downlink input configured to receive downlink communications signals using a first protocol and at least one communications interface configured to receive and provide the downlink communications signals to a remote unit. The distributed communications system comprises the remote unit, which in turn comprises a global positioning device configured to determine location information from satellite signals received from one or more global positioning satellites, and a secondary protocol transmitter configured to provide the location information to a wireless client within an antenna coverage area associated with the remote unit using a secondary protocol.
In another embodiment, a method to assist in provision of location based services comprises receiving downlink communications signals at at least one downlink input using a first protocol and providing the downlink communications signals to a remote unit. The method comprises intermittently receiving signals from one or more satellites in a global positioning satellite constellation at a device in the remote unit and calculating a location for the remote unit based on the signals from the one or more satellites. The method comprises providing, through a secondary protocol transmitter from the remote unit location, information to a wireless client within an antenna coverage area associated with the remote unit.
As non-limiting examples, the global positioning satellites may be part of the GPS, GLONASS, Galileo or COMPASS satellite systems. In another non-limiting example, the secondary protocol may be a WiFi signal.
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.
Reference will now be made in detail to the embodiments, examples of which are illustrated in the 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. Whenever possible, like reference numbers will be used to refer to like components or parts.
Embodiments disclosed herein include location tracking for mobile terminals. Related components, systems, and methods are also disclosed herein. For example, the systems disclosed herein can provide location information to mobile terminals that may not be able to receive otherwise global positioning system (GPS) information from the GPS satellites, such as, for example, when the mobile terminal does not receive GPS signals from the GPS satellites. Providing location information to clients inside a building or other location may make location based services, such as emergency (E911) services, for example, possible based on the location information.
Before discussing systems and methods of providing localization services in a distributed communications system, which starts at
With continuing reference to
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To provide further exemplary illustration of how an optical fiber-based distributed communications system can be deployed indoors,
With continuing reference to
The main cable 52 enables multiple optical fiber cables 56 to be distributed throughout the building infrastructure 40 (e.g., fixed to the ceilings or other support surfaces of each floor 42, 44, 46) to provide the antenna coverage areas 50 for the first, second, and third floors 42, 44, and 46. In an example embodiment, the HEU 12 is located within the building infrastructure 40 (e.g., in a closet or control room), while in another embodiment the HEU 12 may be located outside of the building infrastructure 40 at a remote location. A base transceiver station (BTS) 58, 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 terminal enters the cell, the BTS communicates with the mobile terminal. Each BTS includes at least one radio transceiver for enabling communication with one or more subscriber units operating within the associated cell.
For most E911 and most other location based services, the client device 24 provides its location information to the provider of the location based services. In some systems, like the uplink time-difference of arrival systems of the Global System for Mobile Communications (GSM), the network may provide the location information, not the handset. As noted above, one of the issues associated with providing location information is ascertaining the location of the client device 24. This issue is exacerbated when the client device 24 is indoors because satellite signals suffer from absorption in building materials. If the client device 24 could receive location information from a distributed communications system 10, the client device 24 could use that information in conjunction with location based services. In many instances, the location based services do not need an extremely fine resolution (e.g., less than one meter) of the location of the client device 24. That is, a reasonably coarse location determination (e.g., within ten to twenty meters) may be sufficient for most location based services. If the RAU 14 (or other access point element associated with the distributed communications system 10) knows its location and can send that location to the client device 24, then the client device 24 can treat the location of the RAU 14 (or other access point element) as the location of the client device 24. However, as noted, satellite signals are not reliable indoors, so it may be difficult for the RAU 14 to learn its location. The present disclosure provides techniques through which the distributed communications system 10 can learn the location of elements within the distributed communications system 10 and convey those locations to proximate client devices 24.
In this regard,
A second exemplary embodiment is illustrated in
The global positioning devices 74 experience the same problems in receiving satellite signals as the client devices 24. That is, the global positioning devices 74 are positioned inside a building which may act to occlude or otherwise attenuate the signals from the satellites 62. However, the fixed positions of the global positioning devices 74 allow for a higher probability that the global positioning devices 74 are able to determine a location of the respective RAU 14A, 14B with reasonable accuracy.
In this regard,
Normally, global positioning systems need three satellites with which to trilaterate to ascertain location. In an alternate embodiment, the controller may use technology developed by Rx Networks Inc. of 1201 W. Pender Street, Suite 800, Vancouver, British Columbia, Canada, V6E 2V2. Rx Networks has developed a system whereby if only two satellites are visible, an algorithm can be applied to ascertain that the solution to the location equations is one of two possible locations on the earth's surface. Using external data, such as coarse location information like cell-sector ID or WiFi-AP ID, the correct one of the two possible locations is determined. Such coarse location information should be readily available since the distributed communication system 10 is deployed in a venue of a generally known geo-location (e.g., street address or the like).
With continuing reference to
The HEU 12, RAU 14, client device 24 or other devices disclosed herein can include a computer system.
The computer system 200 in this embodiment includes a processing device or processor 204, a main memory 216 (e.g., read-only memory (ROM), flash memory, dynamic random access memory (DRAM) such as synchronous DRAM (SDRAM), etc.), and a static memory 208 (e.g., flash memory, static random access memory (SRAM), etc.), which may communicate with each other via the data bus 210. The static memory 208 may correspond to memory 98(1)-98(N) (as shown in
The processing device 204 represents one or more general-purpose processing devices such as a microprocessor, central processing unit, or the like. More particularly, the processing device 204 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 204 is configured to execute processing logic in instructions for performing the operations and steps discussed herein.
The computer system 200 may further include a network interface device 212, and may or may not include an input 214 to receive input and selections to be communicated to the computer system 200 when executing instructions. The computer system 200 also may include an output 217, including a display, a video display unit (e.g., a liquid crystal display (LCD) or a cathode ray tube (CRT)), an alphanumeric input device (e.g., a keyboard), and/or a cursor control device (e.g., a mouse).
The computer system 200 may or may not include a data storage device that includes instructions 218 stored in a computer-readable medium 220. The instructions 218 may also reside, completely or at least partially, within the main memory 216 and/or within the processing device 204 during execution thereof by the computer system 200. Main memory 216 and the processing device 204 also constitute computer-readable medium as that term is used herein. The instructions 218 may further be transmitted or received over a network 222 via the network interface device 212.
While the computer-readable medium 220 is shown in an exemplary embodiment to be a single medium, the term “computer-readable medium” should be taken to include a single medium or multiple media (e.g., a centralized or distributed database, and/or associated caches and servers) that store the one or more sets of instructions. The term “computer-readable medium” shall also be taken to include any medium that is capable of storing, encoding or carrying a set of instructions for execution by the processing device and that cause the processing device to perform any one or more of the methodologies of the embodiments disclosed herein, and thus includes solid-state memories, optical and magnetic medium, and carrier wave signals.
The steps of the embodiments disclosed herein may be performed by hardware components or may be embodied in machine-executable instructions, which may be used to cause a general-purpose or special-purpose processor programmed with the instructions to perform the steps. Alternatively, the steps may be performed by a combination of hardware and software.
The embodiments disclosed herein may be provided as a computer program product, or software, that may include a machine-readable medium (or computer-readable medium) having instructions stored thereon, 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.), a machine-readable transmission medium (electrical, optical, acoustical or other form of propagated signals (e.g., carrier waves, infrared signals, digital signals, etc.)), etc.
Unless specifically stated otherwise, discussions utilizing terms such as “processing,” “computing,” “determining,” “displaying,” or the like, refer to the action and processes of a computer system, or similar electronic computing device, that manipulates and transforms data represented as physical (electronic) quantities within the computer system's registers and memories into other data similarly represented as physical quantities within the computer system memories or registers or other such information storage, transmission, or display devices.
The algorithms and displays presented herein are not inherently related to any particular computer or apparatus. Various systems may be used with programs in accordance with the teachings herein, or it may prove convenient to construct more specialized apparatuses to perform the method steps. The embodiments described herein are not described with reference to any particular programming language and a variety of programming languages may be used to implement the embodiments.
The various illustrative logical blocks, modules, circuits, and algorithms described in herein may be implemented as electronic hardware, instructions stored in memory or in another computer-readable medium and executed by a processor or other processing device, or combinations of both. The components of the distributed antenna systems may be employed in any circuit, hardware component, integrated circuit (IC), or IC chip, as examples. Memory may be any type and size of memory and may be configured to store any type of information desired. To clearly illustrate this interchangeability, various illustrative components, blocks, modules, circuits, and steps have been described above generally in terms of their functionality. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present embodiments.
The various illustrative logical blocks, modules, and circuits described in connection with the embodiments disclosed herein may be implemented or performed with a processor, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA) or other programmable logic device, 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.
The operational steps described in any of the exemplary embodiments are described to provide examples. The operations described may be performed in different sequences other than the illustrated sequences. Furthermore, operations described in a single operational step may be performed in a number of different steps, and one or more operational steps may be combined. The steps illustrated in flow charts may be subject to numerous different modifications as will be apparent to one of skill in the art. Data, instructions, commands, information, bits, symbols, and chips referenced throughout the above description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.
As used herein, it is intended that the 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.
The antenna arrangements disclosed herein may include any type of antenna desired, including but not limited to dipole, monopole, and slot antennas. The distributed antenna systems can include any type or number of communications mediums, including but not limited to electrical conductors, optical fiber, and wireless transmission, and may be configured to transmit and receive any type of communications signals, including RF communications signals and digital data communications signals, as well as multiplexing (e.g., WDM and FDM), examples of which are described in U.S. patent application Ser. No. 12/892,424, entitled “Providing Digital Data Services in Optical Fiber-based Distributed Radio Frequency (RF) Communications Systems, And Related Components and Methods,” incorporated herein by reference in its entirety.
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. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.
This is a continuation of International Application No. PCT/US2013/034336, filed Mar. 28, 2013, which claims the benefit of priority under 35 U.S.C. §119 of U.S. Provisional Application No. 61/618,373, filed on Mar. 30, 2012, the contents of which are relied upon and incorporated herein by reference in its entirety.
Number | Date | Country | |
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61618373 | Mar 2012 | US |
Number | Date | Country | |
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Parent | PCT/US2013/034336 | Mar 2013 | US |
Child | 14486469 | US |