Patent Grant
7084574
The present invention relates generally to wireless networks and more particularly to the installation of wireless network components in a dwelling, commercial building, industrial facility, campus environment, tunnel, parking garages and other locations where gaps in wireless signal coverage may be prevalent or an increase in network capacity may be desirable.
The term “wireless network” is used herein to refer to any network to which a wireless computing device or a wireless communications device can connect through wireless means. A wireless connection is commonly achieved using electromagnetic waves, such as radio frequency (“RF”) waves, to carry a signal over part or all of the communication path. Wireless networks can be private or public in nature and can be designed for two-way communications or for one-way broadcasts. As wireless computing devices and wireless communications devices become more and more prolific, the demand increases for more ubiquitous access to these wireless networks.
Private wireless networks often serve a single building, campus or other defined location. To meet current government regulations for use of the radio frequency spectrum, a low signal transmit level is often used in these types of environments. This low transmit level allows the wireless signal to be effectively limited to the desired area by using walls, furniture, other obstructions, or even free space to attenuate and contain the signal. While a low transmit level works well to contain the wireless signal, it can also have the unintended consequence of allowing undesired gaps in the coverage area.
Wireless signal coverage gaps are also common in public networks. For example, two way communications networks, such as, cellular networks, PCS networks, paging networks, and mobile data networks, are often characterized by gaps in wireless signal coverage in areas such as tunnels, building lobbies, public gathering spaces, airports, public arenas, convention facilities, office spaces, etc. As another example, one way broadcast networks, such as satellite radio networks, GPS networks, or even AM radio stations, also tend to include wireless signal coverage gaps in areas such as buildings, public arenas, tunnels, or even under highway overpasses.
To provide wireless signal coverage within the gaps of a wireless network or to add traffic carrying capacity, additional network equipment is usually required. A common method of covering a gap or adding capacity is to place an additional network access point, such as a base station, in a location where it can communicate with one or more wireless computing device or wireless communications device located in or near the gap. A network access point may or may not require a dedicated hard-wired communications facility to or from the hardwired network. Adding network access points to a wireless network can allow additional communication channels to be added to the wireless network and usually allows additional traffic carrying capacity to be added as well. Both wired and wirelessly interconnected network access points are well known in the art.
In locations where additional channels or traffic carrying capacity is not needed on the wireless network, a wireless repeater, wireless reradiator, or wireless signal booster can be used to cover a gap. Usually a wireless repeater, wireless reradiator, or wireless signal booster receives the wireless signal over the air and then repeats the wireless signal or regenerates the wireless signal on either the same channel or another wireless channel. Wireless repeaters, wireless reradiators, and wireless signal booster are well known in the art. The benefits of using a wireless repeater, wireless reradiator, or wireless signal booster instead of a network access point can be a reduction in cost, size, power consumption and/or the lack of a need for a back-haul communications facility to the network.
Hereinafter, network access points, wireless repeaters, wireless reradiators, wireless signal boosters and other wireless network devices, such as hubs, routers gateways, etc. are referred to collectively as “wireless network components.” In many cases the optimal location for a wireless network component, for purposes of maximizing wireless signal coverage, is an overhead location. Unless a building or other structure is pre-wired to accommodate the installation of wireless network components in overhead locations, commercial power sources will typically not be readily available in such overhead locations. To install a wireless network component in an overhead location, a commercial power line must be run to the overhead location or the wireless network component must be designed to work off of an alternative power source, such as solar power, battery power, a power generator, or the like.
The cost of running a commercial power line or providing alternative power to a wireless network component often far eclipses the cost of the network component itself, and thus renders implementation impractical for many applications. Also, hard-wiring of the wireless network component to the commercial power supply or installing a new electrical outlet for the wireless network component makes it more difficult to rapidly reconfigure the wireless network by moving the wireless network component to another location. Since wireless coverage is often difficult to predict and because changes in the environment can adversely impact the coverage, capacity and/or quality of a wireless system, it is often necessary to change the location of a wireless network component from time to time. If the wireless network component is designed to be permanently connected to a power supply, requires special skills to relocate, or is not otherwise easily relocated or moved, the network administrator may tend to sub-optimize the network coverage or capacity due to the expense and/or difficulty of making rapid reconfigurations.
In most overhead locations where a wireless network component is desirable, a lighting source is usually available. For example incandescent lights are commonly available in homes. Compact electric discharge lamps, hereinafter referred to generally as “fluorescent lamps,” are commonly available in office complexes, industrial buildings, manufacturing facilities, parking garages, airports and other locations. Other types of well known lighting sources are spot lights commonly available on the external walls of dwellings and businesses, street lights commonly available in neighborhoods, and security lights commonly available in campus environments or the external areas of commercial facilities. Usually most of these lighting sources have ample power available to power the existing lighting as well as another device.
It is known in the art that a wireless network component can be mounted and electrically connected between an incandescent light fixture and an incandescent light bulb. For example, the wireless network component can be fitted on one side with a “male” coupling that screws into the light socket. On the opposite side, the wireless network component can be fitted with a female coupling into which the light bulb can be screwed. The male and female couplings can be electrically connected to the input and output power lines of the wireless network component to complete a circuit. Such a configuration is shown in U.S. Pat. No. 6,400,968 issued to White, et al.
Fluorescent lights, however, are more prevalent than incandescent lights in business facilities, airports, commercial and industrial buildings and other locations where wireless network coverage is more likely to be needed. As used herein, the term “fluorescent light” is intended to encompass the fluorescent light fixture and the fluorescent lamp. Fluorescent light fixtures designed for linear fluorescent lamps include laterally spaced connectors that receive the pin or pins protruding from each end of the fluorescent lamp. The lateral space between said connectors is typically substantially equivalent to the length of the fluorescent lamp. Thus, due to space constraints, there is not a simple way to mount and electrically connect a wireless network component in between the fluorescent light fixture and the fluorescent lamp. Similar space constraints exist within fluorescent light fixtures designed for U-bent fluorescent lamps, Circline fluorescent lamps, etc.
Florescent lights are known to generate RF noise, which can cause harmful interference to the normal operations of electronic devices and radio transmitters. This noise is generally a result of the proper operation of either the fluorescent power supply or the fluorescent lamp itself.
Accordingly, there is a need to overcome the limitations of the prior art by adapting a wireless network component to utilize the power source of a fluorescent light that is readily available in many overhead locations. There is an additional need for adapting a wireless network component to utilize the power source of a fluorescent light while reducing or minimizing the impact on the wireless network component of RF noise generated by the fluorescent light.
The present invention satisfies the above-described need by providing systems and methods for deriving power for a wireless network component, or other device, from the power source of a fluorescent light. In accordance with certain aspects of the invention, a first power coupling is electrically connected to at least a first pin of a fluorescent lamp and to a power converter of the wireless network component. A second power coupling is electrically connected to at least a second pin of the fluorescent lamp and to the power converter of the wireless network component device, such that a circuit is completed between the power converter, the first pin and the second pin. Power supplied to the pins by the power source of the fluorescent light will be drawn by the circuit to power the wireless network component. The fluorescent lamp still receives sufficient power to provide at least some of the intended illumination.
On linear fluorescent lamps, the first pin may be located at a first end of the fluorescent lamp and the second pin may be located at a second end of the fluorescent lamp. In the case of linear fluorescent lamps, the first power coupling is spaced apart from the first end of the fluorescent lamp and from a first connector in the fluorescent light fixture by one or more first insulating means. Similarly, the second power coupling is spaced apart from the second end of the fluorescent lamp and from a second connector in the fluorescent light fixture by one or more second insulating means. The first power coupling and the second power coupling may each be configured for making electrical connection with one or more of a bi-pin fluorescent lamp, a single-pin fluorescent lamp or any pin or other connector configuration for linear fluorescent lamps. On other types of fluorescent lamps, such as U-bent or Circline lamps, the first pin and the second pin may both be located at a first end of the fluorescent lamp. In such a case, the first power coupling and the second power coupling may both be spaced apart from the first end of the fluorescent lamp and from a connector in the fluorescent light fixture by one or more insulating means.
At least one of the first power coupling or the second power coupling may be electrically connected to the power converter of the wireless network component via a power tether. Alternatively or in addition, at least one of the first power coupling and/or the second power coupling may be electrically connected directly to the power converter of the device. The wireless network component may be configured to receive network data and control signals from a second wireless network component via wireless communications. Alternatively or in addition, the wireless network component may be designed to communicate with a second network component via a power line carrier system.
Another aspect of the invention allows a power coupling to be inserted between one of the ends of a fluorescent lamp and the connectors within a fluorescent light fixture. In this configuration a circuit is completed between the power coupling, the pins of the fluorescent lamp and the connectors of the fluorescent light fixture. The power coupling is electrically connected to a wireless network component, which may be mounted in, on or near the fluorescent light fixture. Similarly, a power coupling may be inserted between two connectors within a fluorescent light fixture. In this configuration a circuit is completed between the power coupling and the connectors of the fluorescent light fixture. The circuit may terminate in a plug or other power port. A wireless network component mounted in, on or near the fluorescent light fixture may be electrically connected to the power port by way of a power cord, etc.
In accordance with other aspects of the invention, a power source of a fluorescent light is configured for supplying power to a wireless network component or other external device. The power source of the fluorescent light includes a fluorescent ballast for receiving an input voltage via an input line and for converting the input voltage to a lamp voltage suitable for powering a fluorescent lamp. The power supply also includes a first output line electrically connecting the fluorescent ballast to the connectors, which are designed primarily to receive the pins of a fluorescent lamp, within a light fixture for outputting the lamp voltage to the connector. In addition, the power supply includes a second output line electrically connecting the fluorescent ballast to a power port for outputting an external device voltage, which is suitable for powering the external device, to the power port. The power port may be integrated within a housing that contains one of the connectors that receives the pins of a fluorescent lamp. The power port may alternatively be mounted on or near the light fixture.
The power source of the fluorescent light may also include a third output line for extracting network data and control signals from power line carrier signals on the input voltage. The power source may further include a signal bypass network electrically connected to the input line and to at least one of the first output line and the second output line for allowing power line carrier signals to bypass the fluorescent ballast.
In accordance with still other aspects of the present invention, a wireless network component that derives power from the power source of a fluorescent light includes: a first power coupling that is electrically connected to the power converter of the wireless network component and which is configured for electrically connecting to a first connector within a fluorescent light fixture; a second power coupling that is electrically connected to the power converter of the wireless network component and which is configured for connecting to a second connector within the fluorescent light fixture to thereby complete a circuit between the power converter, the first connector and the second connector. Power supplied to the first connector and second connector by the power source of the fluorescent light will be drawn by the circuit to power the wireless network component.
The wireless network component may be housed in a housing shaped substantially similar to a fluorescent lamp. In such a configuration, the first power coupling is positioned at a first end of the housing and the second power coupling is positioned at a second end of the housing. The first power coupling and the second power coupling may each be shaped to mimic one or more pin of a fluorescent lamp. The housing may include a compartment for receiving and powering a fluorescent lamp having the same style and form factor as the fluorescent lamp intended for the fluorescent light fixture or one or more fluorescent lamp that is shorter than intended for the fluorescent light fixture. In that case, one of the power couplings may be electrically connected to the power converter of the wireless network component via the short fluorescent lamp. The wireless network component may also include at least one external antenna, which may or may not be removable.
Another aspect of the present invention provides methods and components for reducing or minimizing the effect of noise that the power source of a fluorescent light will inevitably introduce to the power lines (e.g., circuits, power converter feeds, associated power tethers, etc.) of the wireless network component. The noise is dampened by grounding one or more power line of the wireless network component to a ground source through at least a portion of the florescent light fixture or through the ground of the florescent light power source. The wireless network component may include grounding components comprising a ground wire or other grounding means, a capacitor or similar component for avoiding coupling of significant amounts of electrical current. The ground wire or other grounding means may be designed for temporary contact with the grounding source, to allow for relocation of the wireless network component as needed or desired.
These and other aspects, features and embodiments of the present invention will become apparent to those skilled in the art upon consideration of the following detailed description of illustrated embodiments exemplifying the best mode for carrying out the invention as presently perceived.
The present invention provides systems and methods for powering a wireless network component with power drawn from a fluorescent light. In accordance with certain embodiments of the invention, a wireless network component may be configured to draw power from the pins of a fluorescent lamp. In accordance with other embodiments, a wireless network component may be configured to interface directly with the lamp connectors (also referred to as contacts) in the fluorescent light fixture. In either configuration, the invention allows a wireless network component to derive the power needed for its own operation, while still allowing the fluorescent lamp to provide illumination to the intended area.
A wireless network component according to the present invention derives its power directly from a fluorescent light without the need for additional electrical wiring. This eliminates the need for highly skilled labor to install the wireless network component. Installation of the inventive wireless network component does not require any additional skills or specialized tools beyond those required to replace a fluorescent lamp. This ease of installation enables a network administrator to easily expand the coverage of a wireless network by adding additional wireless network components as necessary or desired. In addition, the inventive wireless network component can be relocated from one fluorescent light to another, allowing a network administrator to easily reconfigure the coverage pattern of the wireless network.
In certain other embodiments of the present invention, the ballast of a fluorescent light fixture can be reconfigured to provide power to both the fluorescent lamp and an external device, such as wireless network component. The reconfigured ballast may include a power outlet or other power coupling for interfacing with the wireless network component. The power coupling may be located within the fluorescent light housing or provided as an addition to the connectors used to mount the fluorescent lamp. In this manner, once the reconfigured ballast and power coupling are installed in a light fixture, a wireless network component can be easily added or moved.
The present invention presumes that the wireless network component is mounted in a suitable overhead location on or near the fluorescent light. Preferred methods and structures for mounting a wireless network component on a fluorescent light are described in co-pending U.S. patent application Ser. No. 10/790,644, filed Mar. 1, 2004, which is commonly owned by the present assignee and incorporated herein by reference in its entirety. However, other methods for overhead mounting of a wireless network component are possible, including but not limited to the use of brackets, adhesives, magnetic couplings, screws, nails and other fasteners, hooks, etc. It should therefore be appreciated that the present invention is not limited to any particular mounting configuration of a wireless network component.
As mentioned previously, certain wireless network components may function as base stations, wireless hubs, or wireless routers. Thus, in certain embodiments, it may be necessary for the wireless network component to receive control and transport signals from the wireless network. As an example, the wireless network component may communicate with the wireless network via a traditional hard-wired facility, such as Ethernet, telephone cable, T-1, or other similar means. As an alternative example, the wireless network component may communicate with the wireless network using a power line carrier system. Power line carrier systems, which are well know in the art, allow a broadband data signal to be transported via the power lines as a distribution type network. A typical power line carrier system is described in U.S. Pat. No. 6,492,897 to Mowery, Jr., which is incorporated herein by reference.
To avoid running a hard-wired communications facility to a wireless network component, or connecting the wireless network component to a power line carrier system, the wireless network component may alternatively communicate with the wireless network via in-band wireless, out of band wireless, free space optical, infrared, or any other suitable wireless communication technology. In certain embodiments, the wireless network component may be designed to communicate with one or more other wireless network component via free space optical or infrared devices positioned above the plenum ceiling or otherwise. Such a configuration could allow the wireless network component to derive power from a fluorescent light while inconspicuously and receiving wireless data and control signals from another wireless network component. Wireless communications between the wireless network component and the wireless network allow the wireless network component to be more easily moved from one location to another.
Referring now to the attached figures, in which like numerals represent like elements, certain exemplary embodiments of the present invention will hereafter be described.
The use of the power connector caps 104,106 and the one or more power tether 108 allows the wireless network component 100 to be installed when the fluorescent lamp 102 is not installed in the light fixture. In other embodiments, the power connector caps 104,106 and possibly the power tether 108 can be incorporated directly into the fluorescent lamp. A power tether 108 may be expandable and/or retractable so as to provide greater flexibility for use with different length fluorescent lamps 102 and/or positioning of the wireless network component 100 along the length of a fluorescent lamp 102.
When drawing power from a fluorescent lamp 102 for a wireless network component 100, a major obstacle to overcome is the amount of noise present in the circuit. The present invention overcomes this obstacle by grounding the circuit back to a metal surface within the housing of the fluorescent light fixture. An exemplary grounding means, a ground wire 110, is shown in
The inside connector cap 202 may be designed to include one or more alignment pin 208. The outside connector cap 204 and the power coupling 206 may each be designed to include one or more corresponding alignment holes 210. Accordingly, the three components may be aligned for assembly using the one or more alignment pin 208 and the corresponding alignment holes 210. The one or more alignment pin 208 may optionally be designed to snap into the corresponding alignment holes 210. Alignment pins 208 and alignment holes 210 are optional features of the invention and are provided merely for ease of assembly. Alternatively, alignment markings or other alignment indexes may be supplied to facilitate proper assembly of the exemplary power connector cap 104. Furthermore, the exemplary power connector cap 104 may by designed without any alignment pins 208, alignment holes 210 or other alignment indexes. In other embodiments, or conductive material of the power coupling 206 may be coated with a nonconductive material, such as plastic, eliminating the need for one or more of the inside connector caps 202 and the outside connector cap 204.
The inside connector cap 202, the outside connector cap 204 and the power coupling 206 each include a center passage 212, 214, 216 through which the pins of the fluorescent lamp 102 will pass. The center passage 216 of the power coupling 206 is shaped so that at least one pin of the fluorescent lamp 102 makes electrical contact with the power coupling 206. As shown in
The power coupling 206 is connected to the power converter of the wireless network component 100, either directly or by using a power tether 108, via a connector 218. The connector 218 may be configured as a pin, clip, plug, or any other suitable electrical connection mechanism. Thus, when power is supplied to the fluorescent lamp 102, power flowing across at least one pin of the fluorescent lamp 102 is drawn by the power coupling 206 and is directed to the power converter of the wireless network component 100. A second power coupling (not shown) connected to the power converter of the wireless network component 100 and to a pin on the opposite end of the fluorescent lamp 102 completes the circuit.
The alternative power coupling 206′ includes a center passage 306 through which the pin or pins of a fluorescent lamp 102 pass. The center passage 306 is shaped so that at least one pin of the fluorescent lamp 102 makes electrical contact with the conducting layer 304. As shown in
The alternative power coupling 206′ is connected to the power converter of the wireless network component 100, either directly or by using a power tether 108, via a connector 308. The connector 308 may be configured as a pin, clip, plug, or any other suitable electrical connection mechanism. When power is supplied to the fluorescent lamp 102, power flowing across at least one pin of the fluorescent lamp 102 is drawn by the alternative power coupling 206′ and is directed to the power converter of the wireless network component 100. A second alternative power coupling (not shown) may be connected to the power converter of the wireless network component 100 and to a pin on the opposite end of the fluorescent lamp 102 to complete the circuit.
The exemplary power connector caps 104, 106 and power couplings 206, 206′ shown in
Mounting a wireless network component 100 to a fluorescent light provides an abundance of location choices for the wireless network component 100, as generally illustrated in
Of the three potential wireless coverage areas 404, 408, 412, it can be seen that the second potential coverage area 408 provides the most overlap with the desired coverage area 414 in the example of
In alternative embodiments of the present invention, power for a wireless network component 100 may be drawn from the power supply of a fluorescent light, as opposed to the pins of the fluorescent lamp 102.
In embodiments where the wireless network component 100 is used in connection with a power line carrier system, the ballast 606 may further be configured with a separate output line 612 for data and control signals. Such a configuration allows a power line carrier signal to be separated from the input voltage 604 before the voltage is converted and supplied to the fluorescent lamp 102 or the external device. Thus, the separate output line 612 would allow a clean data and control signal to be isolated before power supply noise is introduced. In this manner, a greater data and control signal throughput may be possible. One skilled in the art will appreciate that the data and control signal can also or alternatively be output from the power supply 602 using a power line carrier signal on the external device voltage 610.
In certain other embodiments, the signal bypass network 902 can be incorporated into the fluorescent power supply 602. In addition, the signal bypass network 902 may in certain embodiments be equipped to communicate with an external device voltage 610 (see
In still other embodiments of the present invention, the wireless network component 100 may take the shape of a fluorescent lamp 102, as shown by way of example in
Also illustrated in
In the embodiment shown in
As another alternative, the housing 1002 of the wireless network component 100 may have a length that is less than the fluorescent lamp 102 designed for a particular light fixture. The power coupling 1004 on one end of the shorter housing 1002 may be connected to the light fixture and the power coupling on the other end may be configured for mating with the pins on one end of a shorter (than normally required for the light fixture) fluorescent lamp 102. The pins on the other end of the shorted fluorescent lamp 102 may be connected to the other side of the light fixture as normal. The wireless network component 100 may be wired in serial or parallel with the shorter fluorescent lamp 102.
Fabricating the housing 1002 of the wireless network component 100 in the form factor of a fluorescent lamp 102 would allow the rapid installation of the wireless network component 100 into an existing light fixture. It will be appreciated by those of skill in the art that housing 1002 of the wireless network component 100 may also be adapted to other designs, made more ascetic, optimized for antenna placement or designed to fit into a specific light fixture. Accordingly, the exemplary housing 1002 illustrated in
The fluorescent lamp pin connector 1204 is designed to receive and make electrical connection with the one or more pin of the fluorescent lamp 102. The one or more power coupling pin 1202 and the fluorescent lamp pin connector 1204 are electrically connected to the power converter 1206 of the wireless network component 100 to complete a circuit. The fluorescent lamp pin connector 1204 is preferably offset vertically (or horizontally) from the one or more power coupling pin 1202. This offset allows the fluorescent lamp 102 to be installed at a slight angle relative to its intended axis within the fluorescent light fixture. Installation of the fluorescent lamp 102 at a slight angle creates additional space within the fluorescent light fixture in which the wireless network component 100 can be mounted.
The power converter 1206 of the wireless network component 100 converts power from the fluorescent light into a voltage that can be utilized for powering the internal electronics 1208 of the wireless network component 100. At the same time, the power converter 1206 allows sufficient power to pass to the fluorescent lamp 102 so that it can continue to provide at least a portion of the intended illumination. Those skilled in the art will appreciate that the shape of the wireless component 100 shown in
As mentioned above, a wireless network component 100 of the present invention may be used in outdoor locations, for example in conjunction with street lights or security lights common in neighborhoods, campus environments, parking garages, etc. Outdoor lights (and some indoor lights) often include a photoelectric device that prevents power from reaching the lamp (or light bulb) when the ambient light is above a determined threshold. Such a photoelectric device would also prevent power from reaching the wireless network component 100. To overcome this problem, the photoelectric device may be modified so that it does not directly control the power, but instead sends control signals to the wireless network component 100. The control signals would instruct the wireless network component 100 to enable or disable the flow of power to the lamp (or light bulb).
In some embodiments, it may be desirable to include a rechargeable power supplies (e.g., a rechargeable battery) within a wireless network component 100 of the present invention. Power drawn from the power source of a light may be used to simultaneously or alternately charge the rechargeable power supply and power the wireless network component 100. In this way, the wireless network component 100 may continue to operate when the light is turned off. Such an embodiment may be desirable to support network configurations (e.g., mesh networking or peer-to-peer networking) where one wireless network component 100 requires constant communication with another wireless network component 100.
Based on the foregoing, it can be seen that the present invention provides various systems and method for powering a wireless network component 100 from the power source of a light. Many other modifications, features and embodiments of the present invention will become evident to those of skill in the art. It should also be appreciated, therefore, that many aspects of the present invention were described above by way of example only and are not intended as required or essential elements of the invention unless explicitly stated otherwise. Accordingly, it should be understood that the foregoing relates only to certain embodiments of the invention and that numerous changes may be made therein without departing from the spirit and scope of the invention as defined by the following claims. It will be understood that the invention is not restricted to the illustrated embodiments and that various other modifications can be made within the scope of the following claims.
The present application is a divisional of U.S. Non-Provisional patent application Ser. No. 10/785,463 now U.S. Pat. No. 6,979,955 entitled “Deriving Power for a Wireless Network Component from the Power Source of a Fluorescent Light,” filed Feb. 24, 2004, which claims the benefit of the following three provisional patent applications, each of which are incorporated herein by reference: (i) U.S. Provisional Patent Application Ser. No. 60/472,393 entitled “Methods and Apparatus for Attaching a Wireless Network Device to a Lighting Fixture to Derive a Power Source and a Mounting Fixture,” filed May 22, 2003; (ii) U.S. Provisional Patent Application Ser. No. 60/513,720 entitled “Methods and Apparatus for Attaching a Network Device to a Fluorescent Lamp to Derive Power,” filed Oct. 24, 2003; and (iii) U.S. Provisional Patent Application Ser. No. 60/518,506 entitled “Methods and Apparatus for Mounting a Wireless Device by Means of Attaching or Securing to a Fluorescent Lamp,” filed Nov. 7, 2003.
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