Patent Application
20160352422
Embodiments of the invention relate to a multi-functional smart LED system architecture, and in particular, to a smart LED system having several integrated capabilities, including illumination, Internet Protocol (IP)-based radiofrequency (RF) connectivity and visible light communication (VLC).
Light-emitting diodes (LEDs) represent an eco-friendly illumination technology which features high luminous efficiency, long lift time and high reliability. LEDs, which are growing in popularity due to increasing performance and decreasing costs, are often used for lighting, display and signage applications.
In addition, the high response speed of LEDs makes them suitable for electronic modulation, allowing them to be used in visible light communication (VLC) applications. The modulation frequency for LEDs can be set high enough to achieve meaningful data rates and to greatly exceed the flicker fusion threshold of human beings, such that the LEDs' basic illumination function is not affected by the modulation. Compared with traditional wireless radiofrequency (RF) communications, VLC is advantageous in terms of higher security, no RF radiation, wide available spectrum and transceiver simplicity. For example, for downlink communications, VLC is able to reach data rates at the Gb/s level, and, for indoor positioning, VLC is able to achieve accuracy at the sub-meter level.
However, there are also drawbacks to conventional VLC systems. For example, conventional VLC systems lack an effective way to integrate a backhaul system for data delivery to the source of the VLC downlink. For VLC to be used in downlink communications, the data to be transmitted over visible light needs to be delivered to the illumination fixture. Given that the LEDs are always connected to the power line, power line communication (PLC) has been recognized as a potential mechanism for providing a backhaul system. However, PLC devices are expensive and would significantly increase the costs associated with such a LED VLC system. Further, in terms of performance, PLC devices are sensitive to the noise from power grids, resulting in potential drops in data rate and communication interruptions. There is also a limit on the quantity of PLC devices allowed within one power grid, which is another obstacle to deployment of a LED VLC system using PLC technology for a backhaul.
Another drawback relating to VLC systems is that conventional VLC systems lack a mechanism for VLC receivers to request data or other services via an uplink connection.
Embodiments of the invention provide for a multi-functional, smart LED device for a variety of applications, including but not limited to solid-state lighting, display and signage applications. The LED device provides VLC capabilities integrated with IP-based RF wireless connectivity, and includes, for example, a VLC unit, an IP-based RF wireless unit, a control unit with a memory (e.g., a non-volatile memory), and a LED array.
With respect to the VLC capabilities, light from LEDs of the LED array is modulated at a high frequency such that any flickering associated therewith is imperceptible to the human eye. The modulated signal can thus be captured and decoded by nearby VLC receivers without any degradation to the LEDs' lighting functionality.
The IP-based RF wireless connectivity provides a data backhaul and/or uplink for the VLC-based communications, and further allows the VLC-based communications to be utilized as a bridge to extend RF signal coverage for an RF wireless communications network.
Thus, embodiments of the multi-functional, smart LED device discussed herein provide for VLC communications integrated with RF wireless connectivity, while at the same time providing for illumination for various applications (e.g., lighting, display, signage, etc.). Further, the synergy and meshed usage of LED-based VLC and IP-based RF wireless connectivity allows for additional advantages to be achieved, including but not limited to high power efficiency, high reliability and low costs (including overall system costs as well as installation costs).
While the appended claims set forth the features of the present invention with particularity, the invention, together with its objects and advantages, may be best understood from the following detailed description taken in conjunction with the accompanying drawings of which:
Embodiments of the invention provide for a multi-functional, smart LED device for a variety of applications, including but not limited to solid-state lighting, display and signage applications. The LED device provides VLC capabilities integrated with IP-based RF wireless connectivity, and includes, for example, a VLC unit, an IP-based RF wireless unit, a control unit with a memory (e.g., a non-volatile memory), and a LED array.
In an exemplary embodiment, information received via an IP-based RF wireless connectivity interface of the IP-based RF wireless unit is used to program, control and monitor the VLC unit (e.g., including setting the operating frequency of the VLC unit, setting the light intensity of the VLC unit, and determining/transmitting the operating status of VLC unit). Communications between the VLC unit of a device with the VLC of another device are used to extend signal coverage of the RF wireless communications network (i.e., allowing the devices to serve as VLC-based access points to the RF wireless communications network and/or allowing the devices to provide bridges via VLC links to extend coverage of the RF wireless communications network). Alternatively or additionally, the IP-based RF wireless unit may provide a backhaul for the VLC as well as an uplink connection for the VLC. This allows the IP-based RF wireless unit to serve as an RF-based access points to the VLC network and/or allows RF links to act as bridges that extends coverage of a VLC network. In addition, the IP-based RF wireless unit itself may serve as an RF access point to communicate with RF clients and/or communicate with other the IP-based RF wireless units to extent the RF signal coverage. Thus, it will be appreciated that by utilizing the multifunctional, smart LED devices according to embodiments of the invention, a hybrid VLC and IP-based RF system can be formed that utilizes the smart LED devices to provide VLC communication and extend an IP-based RF wireless communication network, as well as provide additional forms of access for both networks. The system may further include smart LED servers, which also provide illumination, bi-directional VLC, and IP-based RF wireless connectivity.
The IP-based RF wireless unit 20 includes, for example, a wireless transceiver (e.g., a WiFi-capable transceiver), and it is capable of receiving and transmitting signals at RF-level frequencies. Internet Protocol (IP) is the set of standards responsible for ensuring that data packets transmitted over the Internet are routed to their intended destinations. The VLC unit 23 includes, for example, a LED driver to power up the LEDs, a VLC modulator to switching the LEDs on/off corresponding to its input data (which may be implemented as or similar to the digital dimming port of a LED driver). The control unit 21 includes, for example, a processor (e.g., a microcontroller) to process commands and data communicated among the RF wireless unit 20, the VLC unit 23 and other devices, and to coordinate their operations. The memory 22, for example, a non-volatile memory (e.g., flash memory or EEPROM), is used to store program(s) and data for the control unit 21. Once the whole smart LED system is powered up, the control unit 21 reads the program and data in the memory 22. The LED or LED array 24 may be a single LED or arrangement of LEDs suitable for various applications, such as lighting, display and signage applications. Depending on the LED driver in the VLC unit 23, the LEDs may be connected in series or in parallel or both.
It will be appreciated that the LED light is modulated to broadcast or transmit information without visibly affecting the illumination function performed by the LED or LED array 24. It will further be appreciated that the specific pathways described above and depicted in
Further, in exemplary embodiments of the invention, data communicated via the VLC unit and the IP-based RF wireless unit can include address information, position information, and/or identity information associated with various terminals. Smart LED devices as described above can thus be used in “location-aware” applications, such as indoor positioning and/or location-based broadcasting, where address, position, and/or identity information corresponding to terminals is exchanged.
It will be appreciated that, although the exemplary embodiments discussed above utilize IP-based RF wireless connectivity and VLC, the principles of the invention are not limited thereto. Other Non-Line-of-Sight (NLOS) and Line-of-Sight (LOS) access protocols may be integrated into network devices that are able to extend the coverage and functionality of each of the respective NLOS and LOS protocols used.
All references, including publications, patent applications, and patents, cited herein are hereby incorporated by reference to the same extent as if each reference were individually and specifically indicated to be incorporated by reference and were set forth in its entirety herein.
The use of the terms “a” and “an” and “the” and “at least one” and similar referents in the context of describing the invention (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. The use of the term “at least one” followed by a list of one or more items (for example, “at least one of A and B”) is to be construed to mean one item selected from the listed items (A or B) or any combination of two or more of the listed items (A and B), unless otherwise indicated herein or clearly contradicted by context. The terms “comprising,” “having,” “including,” and “containing” are to be construed as open-ended terms (i.e., meaning “including, but not limited to,”) unless otherwise noted. Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., “such as”) provided herein, is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention unless otherwise claimed. No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the invention.
Preferred embodiments of this invention are described herein, including the best mode known to the inventors for carrying out the invention. Variations of those preferred embodiments may become apparent to those of ordinary skill in the art upon reading the foregoing description. The inventors expect skilled artisans to employ such variations as appropriate, and the inventors intend for the invention to be practiced otherwise than as specifically described herein. Accordingly, this invention includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, any combination of the above-described elements in all possible variations thereof is encompassed by the invention unless otherwise indicated herein or otherwise clearly contradicted by context.
This patent application claims the benefit of U.S. Provisional Patent Application No. 61/967,423, filed Mar. 18, 2014, which is incorporated by reference.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/CN2014/000971 | 11/5/2014 | WO | 00 |
| Number | Date | Country | |
|---|---|---|---|
| 61967423 | Mar 2014 | US |
