Situational marking and awareness tag (SMART) beacon, system and method

A system and method are disclosed comprising a plurality of small independent light sources which are arranged in a mesh network and capable of exchanging data such that they can be operated together and under control of a controller in order to provide enhanced lighting effects in particular applications.

FIELD OF THE INVENTION

The present invention relates to a SMART beacon system and method. In particular, the present invention relates to a network of small independent lighting sources which can be operated together in order to provide enhanced lighting effects in a variety of situations.

BACKGROUND TO THE INVENTION

The prior art reveals landing systems and the like comprised of a plurality of lights which flash in preprogrammed sequence to improve visibility and provide direction. One drawback of such prior art systems is that they are fixed, typically interconnected by wires and require significant sources of power in order to operate. In many cases, however, such systems could be advantageously used in places which are difficult to access and without any easy access to power.

Also, in chaotic, fast moving, close tactical operations commanders, operators and team members ideally need to know where the location of other team members. Indeed, during such operations team members typically scatter in order to seek cover and avoid enemy fire. Additionally, the current status of team members and their immediate environment would also need to be known. For example, before starting CASEVAC under fire, company medics ideally need to know the location of friendly casualties.

Prior art methods of indicating status and location typically comprise the use of hand signals, visual location and the use of a voice communications over radios and the like, often combined with the use of GPS location devices. One drawback of such methods is that in many cases they require line of sight which in tactical situations is often not possible, due to dead ground or poor visibility conditions, such as rain, snow or smoke. Another drawback is that such methods might result in a team member inadvertently revealing his position, for example through speaking over a radio or coming out from cover. Still another drawback of such methods is that they require active feedback from the team members, which in the case of an severely injured/unconscious team member is typically not possible.

Another drawback of the prior art devices is that GPS devices often lose tracking signals when used indoors, reducing their effectiveness in tactical operations carried within buildings or the like.

The prior art also reveals light emitting beacons for attaching to people and objects for purposes of identification, avoidance and rescue. These beacons emit light according to predefined signatures, for example according to the ubiquitous SOS signal of three short, three long, three short.

One drawback of such prior art devices, and in particular in cases when a number of individuals are using such devices in proximity to one another, for example in the case of a catastrophe at sea of the like where a plurality of individual life jackets or life rafts are equipped with such light emitting beacons, is that the beacons emit light in an unsynchronized manner. This leads to overall poor visibility which would be greatly increased by synchronizing the light emitting beacons of one individual or boat with that of another such that they emit light simultaneously and according to the same signature.

SUMMARY OF THE INVENTION

In order to address the above and other drawbacks there is disclosed a beacon lighting system comprising: a wireless control channel, a plurality of small independent light sources each comprising a wireless transceiver for communicating via the wireless control channel, an independent power source, at least one LED and a clock synchronized to a common time source, and a master controller for transmitting control data to each of the plurality of small independent light sources via the wireless control channel, wherein when at least a first one of the plurality of small independent light sources is outside a transmission range of the master controller and at least a second one of the plurality of small independent light sources is within range of the master controller and the first one, the second one relays the control data received from the master controller to the first one and further wherein the plurality of small independent light sources subsequently emits light according to the control data and the common time source.

There is also disclosed a beacon tactical system comprising a wireless communication channel, a controller emitting a control signal comprising an indication that the control signal should be relayed, and a plurality of wearable beacons, each of the beacons comprising an independent power source, a transceiver for transmitting and receiving on the wireless communication channel and at least one LED for emitting a preprogrammed sequence of light flashes in response to the control signal transmitted by the controller and received at the transceiver via the wireless communication channel, wherein when at least a first one of the plurality of wearable beacons is outside a transmission range of the controller and at least a second one of the plurality of wearable beacons is within range of the controller and the first one and provided the control signal indicates that it should be relayed, the second one relays the control signal received from the controller to the first one and further wherein the plurality of wearable beacons which have received the control signal subsequently emit light according to the received control signal.

Additionally, there is disclosed a clustered beacon system comprising: a plurality of independent portable light emitting beacons, each of the beacons comprising a light emitting source, an independent power source and a wireless transceiver having a range, wherein when at least one of the beacons is within range of at least one other of the beacons, the in range beacons exchange synchronizing transmissions via their respective transceivers and further wherein each of the in range beacons subsequently emits a sequence of synchronized light flashes in accordance with data contained within the synchronizing transmissions.

DETAILED DESCRIPTION OF THE ILLUSTRATIVE EMBODIMENTS

Referring now toFIG. 1, the SMART beacon10is a small independent light source comprising at least one LED12within a housing14and covered by a transparent lens16. A rotary switch18positioned about the lens16is provided, whereby through rotation a user can select one of a plurality of modes of operation of the SMART beacon10, at least one of these modes being an “off” position wherein the SMART beacon10does not function. A battery compartment20is also provided for housing an independent power source such as a battery (not shown) for powering the one or more LEDs12. The battery compartment20is accessible via a battery compartment cap22which may be removed in order to replace the battery. In a particular embodiment the one or more LEDs as in12may comprise LEDs of different colours visible to the naked eye, or infra-red or other LEDs visible only with a suitable viewing device.

Referring now toFIG. 2, in a first embodiment the SMART beacon electronics24comprise a controller or CPU26which provides control signals to an LED driver28based on software routines and configuration/control data stored in ROM/RAM30, user inputs received via the rotary switch18and control data received via a wireless transceiver32and its associated antenna34. The LED driver28in turn illuminates the one or more LEDs as in12according to the control signals, for example according to a predetermined sequence of flashes, selection of LED colour and/or intensity. Illustratively, five (5) LEDs as in12are provided, one emitting red light, one emitting blue light, one emitting green light, one emitting white light and one emitting I/R light. Additionally a GPS receiver36and GPS antenna38is optionally provided in order to provide the location of the SMART beacon10. Operation of the CPU26is synchronized using a onboard clock40which can illustratively be synchronized, when available, with clock of the GPS system via the GPS receiver36. Alternatively, synchronization between SMART beacons as in10can be ensured by periodically propagating a common time/system clock between SMART beacons. In this regard, it is unnecessary that all SMART beacons are synchronized to a universal time source, rather what is required is that all SMART beacons that are working in concert to illuminate according to a combined effect are synchronized to a common time source. Illustratively, the onboard clock40operates at 32 khz and a system clock of 32 bits accuracy is propagated during message transmission such that good synchronization between SMART beacons can be maintained if a system clock is propagated at least once every three hours. Illustratively, a group of SMART beacons is considered synchronized if the onboard clocks of all SMART beacons of the group are within about 40 milliseconds.

Still referring toFIG. 2, it is foreseen that the wireless datalink transceiver32and its associated antenna34are used to establish and communicate in the 915 MHz band, for example (and as will be discussed in more detail below) with a master controller device or the like whereby the datalink transceiver32and its associated antenna34is also used to establish and communicate locally via the wireless datalink in the 915 MHz band with other SMART beacons as in10. In order to address a given SMART beacon as in10via the datalink, each SMART beacon10is provided with a unique identification, or node ID, for example stored in ROM/RAM30, or hardwired for example into the datalink transceiver32. The wireless datalink connection is bidirectional, allowing control signals/control data to be sent to the SMART beacons an in10, and operational data, such as status or position if available (and as will be discussed in more detail below), to be sent from the individual SMART beacons as in10to a master controller.

Referring toFIG. 3in addition toFIG. 2, as discussed above, the Smart Beacons as in10each comprise a rotary switch18Illustratively via which the user can select one of a plurality of modes of operation. Additionally, the orientation of the of the battery44in the battery compartment20can also be used as an input to the mode of operation, thereby effectively doubling the number of modes of operation which can be selected by the rotary switch18. Illustratively, orientation of the battery44in the battery compartment20is used to switch of operation between general modes of operation, for example between a first mode of operation where the SMART beacon10operates independently and a second mode of operation where the SMART beacon10is able to communicate with other SMART beacons as in10, for example via at least one communications channel dictated by the position of the rotary switch18. These modes are provided in the table below:

Referring now toFIG. 4, a SMART beacon lighting system, general referred to using the reference numeral48, will now be described. The system48is comprised of a mesh network of small independent light sources such as in10, such as the self powered SMART beacon10, interconnected with other proximate SMART beacons as in10via a wireless control channel (datalink) as in50. In this regard, and in order to reduce power consumed for communications, the range of the SMART beacons as in10is limited (for example a nominal range of about or less than 500 feet when the beacon12is positioned on the ground is foreseen) whereby, and as will be discussed in more detail below, each of the SMART beacons as in10comprises the necessary transceiver functions in order to function as a repeater, thereby allowing messages transmitted to a given SMART beacon as in10to be relayed by another SMART beacon as in10if this is so indicated. Again, the datalink illustratively operates in the 915 MHz band at a rate of 128 kbits/sec.

Note that, in a particular embodiment, the particular message transmitted by the master controller52may include an indication that it is not to be relayed to other SMART beacons as in10. This is useful, for example, to limit the propagation of messages to SMART beacons as in10which are only within direct contact with the master controller52. For example, in a particular embodiment the message may include control data to the effect that all SMART beacons as in10receiving the message switch for a short period of time from infrared to visual light and flash quickly with a high intensity, allowing only those SMART beacons as in10in the neighborhood of the master controller52to be quickly visually identified (for example when a squad commander in a battlefield situation wishes to quickly visually locate proximate members of his squad). A large variety of alternative uses of this feature should now be apparent to a person of ordinary skill in the art.

Still referring toFIG. 4, each transmission between the master controller52and a SMART beacon10and between SMART beacons when a message is being relayed, illustratively includes a time stamp which can be used to synchronize the onboard clock40to the system clock if other synchronization means, such as a GPS receiver or the like, are unavailable. In this regard, on receiving a message including a time stamp the SMART beacon10illustratively compares the time stamp with a current time of the onboard clock40, taking into account any inherent and known delays in receiving and processing the time stamp. In the event that the time stamp is fresher than the onboard clock40, the onboard clock40is updated.

Still referring toFIG. 4, when acting as a repeater, each SMART beacon10propagates received messages to a small number of other SMART beacons, illustratively a maximum of five (5), that are within range. As many SMART beacons as in10may be transmitting within the same band, a collision avoidance strategy illustratively comprised of randomly selecting a delay before retransmitting is provided. A list of the node IDs of the (illustratively five) SMART beacons that are within range and to whom messages are being broadcast is maintained within each SMART beacon. Following broadcast, if the SMART beacon fails to receive the same message (each message is provided a unique message ID) in return from one of the SMART beacons found within the list, the message is rebroadcast.

Still referring toFIG. 4, as discussed briefly above, the SMART beacon lighting system48is further comprised of a master controller52which can be used to control the plurality of SMART beacons as in10via a wireless control channel (datalink)54. Illustratively, the master controller52would typically have a range greater than that of the SMART beacons10, nominally this range would be about or less than 3 miles, and would be in the form of a key fob or the like (not shown). In an alternative embodiment the master controller52can act as a bridge or relay in order, for example, to relay control data from an external controller56on board an aircraft or the like via an appropriate wireless link58, for example in order to receive remote instructions to illuminate or extinguish the SMART beacons as in10. Alternatively, the external controller20could be a suitably equipped PDA or Smart Phone of the like which communicates with the master controller52via a Bluetooth connection, USB connection or the like.

Referring back toFIG. 3in addition toFIG. 4, in a networked mode the SMART beacon10would illustratively act under control of the master controller52. Additionally, as discussed above provision has been made such that each SMART beacon10can be addressed individually via their node ID or as a group via a group (or subnetwork) ID. In this regard the node ID is typically static while the group ID can be modified for example by using the master controller52. In one example embodiment the master controller52is able to modify the group ID of all SMART beacons10which are enabled (i.e. turned on) and within range. Subsequent to such modification, all such modified SMART beacons10can be addressed individually via the node ID or collectively via the group ID allowing them all to be, for example, turned off or on using a single command. The group ID also provides that changes in programming of one of the SMART beacons in a particular group is propagated to all the SMART beacons in that group. This is useful, for example, when the signature to be emitted by the SMART beacons is to be modified, there is a requirement that all SMART beacons in the network emit that signature, for example to identify members of a group or unit or the like.

Referring now toFIG. 4andFIG. 5the master controller52is comprised of a controller or CPU60which, using software routines and configuration data stored in ROM/RAM62, user inputs received via the keypad64and potentially other control data received from external devices by a USB interface66, a Bluetooth™ interface68and its associated antenna70or Wifi interface72and its associated antenna74, generates control signals for transfer to one or more SMART beacons as in10via the wireless datalink transceiver76and its associated antenna78. The master controller52is also able to receive operational data, such as an identification of a particular SMART beacon as in10and its position via the datalink transceiver76and its associated antenna78. Illustratively, a battery (not shown) provides the requisite power in order to ensure correct operation of the electronics.

Referring now toFIG. 6in addition toFIG. 1, the keypad64provides an interface via which a user can remotely control a plurality of SMART beacons as in10. The keypad64comprises:a power switch80and power LED82which illuminates when the master controller is operational;an intensity setting display84with associated set button86;a selected channel/group display88with associated set button90;a plurality of buttons as in92for selecting one of the available colours (red, blue, green, white or I/R);a steady mode select button94;a flashing mode select button96;a pair of channel/group select buttons98,100; andan “all off” select button102.

Referring toFIG. 3Bin addition toFIG. 5andFIG. 6, and with reference to Table 1 above, in operation, one or more first SMART beacons as in10are placed in the networked mode by reversing the battery44and then a given channel, for example channel1, is selected for all of the first SMART beacons as in10using their rotary switches18. This same procedure may be repeated with other groups of SMART beacons as in10while selecting a different channel number. Once the SMART beacons as in10are placed in the networked mode and a given channel selected, the key pad64may be used to select and control all networked SMART beacons as in10operating on a particular channel. In this regard, and as will now be clear to a person of ordinary skill in the art, all SMART beacons as in10for a given channel may be controlled to emit light of a given colour (red, green, blue, white and I/R), at a given intensity and in steady mode or flashing mode. Additionally, SMART beacons as in10networked on a first channel may be controlled to emit light of a given colour, intensity and mode which is different or the same as that of SMART beacons as in10networked on a second channel.

Referring toFIG. 4andFIG. 5, as discussed above in a particular embodiment the master controller52is able to communicate with suitably equipped external device56, such as PDAs, Smart Phones, PCs and the like via one of a possible plurality of interfaces such as Bluetooth™68, USB66, or WIFI72.

Referring toFIG. 2andFIG. 7, the external device56is equipped with a touch screen display104which can be used for displaying, for example, images of terrain106and roads108and the like. As each SMART Beacon as in10is equipped with a GPS receiver36and is individually addressable via unique identifier, the GPS position of each SMART beacon as in10associated with the master controller as in56is capable of being displayed as an icon110or the like on the a display104of the external device56. Additional data, such as the ID of a given SMART beacon, its channel, colour and mode can also be displayed in an appropriate display box112displayed adjacent the SMART beacon as in10, for example when the user taps its associated icon110with his finger.

Still referring toFIG. 2andFIG. 7, in a particular embodiment the SMART beacons as in10are illustratively organized into groups as in114,116based, for example, on their channel number or group ID. Also in a particular embodiment, the unique node ID identifier also provides the ability to individually address each of the SMART beacons as in10in order to provide particular effects. For example, in a particular embodiment the SMART beacons as in10of a group as in114may be controlled to provide a directional strobe, or “rabbit ear”, effect, for example in order to provide a pilot visual indications as the direction of approach to a runway or the like. As once placed in operational mode the SMART beacons as in10function independently, in order to ensure that the SMART beacons as in10of a group remain synchronized, the high precision clock available from the GPS receiver36can be taken advantage of.

In this regard, and referring toFIGS. 8A to 8D, in an embodiment the timing of all flashing or strobe illumination effects are determined according to a timing diagram stored within the ROM/RAM30which provides the start time TSand duration TDof a particular illumination effect following reset. The reset is carried out continuously and simultaneously following expiration of a predetermined timeout ΔT in the SMART beacons as in10. Illustratively, the same reset time (e.g. every 20 seconds such that a reset falls on the hour) is used. Illustratively, ΔT is 20 seconds which is of sufficient duration to allow many different and complicated illumination effects to be described, but of limited enough direction to ensure that synchronization is not lost.

In an alternative embodiment of the timing diagram, the master controller52transmits control data to a given node ID or group ID including in a message body a coded description of the signature, or lighting effect, to be emitted by the addressed SMART beacons once activated. Illustratively, any one of the timing diagrams illustrated inFIGS. 8A to 8Dcould form the basis of the message body to be transmitted in this fashion. A typical format would include a sequence of relative delays (starting from time0) before a given LED is turned on or off, and could include other data as well such as the intensity of illumination and the like. A duration ΔT could also be included to indicate when the sequence should restart. In this regard, by applying a function to the synchronized onboard clock mod ΔT, such that the output is reset to zero following each ΔT, a common starting point of the illumination sequence for all SMART beacons can be achieved, thereby providing the system the ability to produce a variety of synchronized and complex illumination effects.

Referring now toFIG. 8Ain addition toFIG. 7, a timing diagram is provided in order to illustrate the operation of the SMART beacon's directional strobe. In operation the group of SMART beacons114which are to provide the directional strobe effect are first positioned on the ground and then, using the external device102, the start time TSof the strobe relative to the other SMART beacons as in10in the group114configured such that it is later than the previous SMART beacons as in10in the direction it is wished to indicate using the directional strobe. Illustratively this would be done by selecting the effect (e.g. Directional Strobe) as well as the position (e.g. 4 of 7) of the SMART beacon within the sequential (“rabbit ear”) strobe effect. Using the unique ID, a control signal would then be sent to the SMART beacon in question via the master controller52.

Referring now toFIG. 9, a SMART beacon tactical system, generally referred to using the reference numeral118, and in accordance with an alternative illustrative embodiment of the present invention will be described. The system118is comprised of a mesh network of small independent self powered SMART beacons as in10interconnected with other proximate SMART beacons as in10via a datalink as in50. As discussed above, in order to reduce power consumed for communications, the range of the SMART beacons as in10is limited whereby each of the SMART beacons as in10comprises the necessary transceiver functions in order to function as a repeater, thereby allowing transmissions addressed to a given SMART beacon as in10to be relayed by another SMART beacon as in10. Illustratively, the datalink operates in the 915 MHz band and is of relatively low power. It is foreseen that each SMART beacon used in the context of the a SMART beacon tactical system118has a nominal range of about 150 feet when attached to a user's upper body. In order to increase range, an additional higher power repeater unit (not shown) could be used, for example attached to the shoulder or helmet of the user.

Still referring toFIG. 9, each of the plurality of SMART beacons as in10is typically worn by a user (not shown) and in a particular embodiment is able to communicate with a variety of physiological sensors as in120also worn by the user via a low power Wireless Personal Area Network (WPAN)122such as Bluetooth, inductive coupling network, or the like. Via the WPAN122, the SMART beacons as in10are also able to communicate with external computing devices124such as personal computers, smart phones and the like. The one or more of the Smart beacons as in10may also be equipped to communicate with additional external computing devices126using a medium or longer range communication link128such as WiFi Hotspot130in the 2.4 GHz band or the like and associated network infrastructure132.

Referring now toFIG. 10, as discussed above, a user134, such as a soldier or tactical police officer or the like, is typically equipped with one or more SMART beacons10and other equipment such weapons138and body armour140. Illustratively, the one or more physiological sensors (reference120inFIG. 9) are integrated into the body armour140or helmet, which, as discussed communicate with the SMART beacon10via the WPAN (reference122inFIG. 9). The physiological sensors120could illustratively be of the type which sense vital signs such as heart rate, body temperature, surface conductivity, accelerometers for sensing stressors such as impact or concussive blows, and the like.

Referring now toFIG. 11, in the alternative embodiment, the SMART beacon electronics142comprise a controller or CPU144which provides control signals to an LED driver146based on software routines and configuration data stored in ROM/RAM148, user inputs received via the rotary switch18and control data received primarily via the datalink transceiver150and its associated antenna152. The LED driver146in turn illuminates the one or more LEDs as in12according to the control signals, for example according to a predetermined sequence of flashes, selection of LED colour and/or intensity. Illustratively, five (5) LEDs as in12are provided, one emitting red light, one emitting blue light, one emitting green light, one emitting white light and one emitting I/R light. Additionally, or alternatively, a thermal emitter could be incorporated to provide thermal signaling.

Still referring toFIG. 11, a GPS receiver154and GPS antenna156are provided in order to provide the location of the SMART beacon10as well as a universal time source. In a particular embodiment an integrated inertial guidance system158, comprising accelerometers and the like (not shown), can be included in order to provide the SMART beacon's10location in environments where the GPS signals are interfered with, such as in urban areas, indoors or the like. The accelerometers of the integrated inertial guidance system158can also be used to sense shock waves such as those resulting from explosive blasts, collisions and the like.

Still referring toFIG. 11, additional interfaces may include a WPAN interface such as a Bluetooth interface160and associated antenna162operating in the 2.4 GHz band as well as a Broadband interface such as a WiFi interface164and associated antenna166operating in the 2.4 GHz band. A power circuit168comprising a battery170and a charge conditioning/rectification circuit172is also provided in order to supply the requisite power for operating the electronics142and powering the one or more LEDs as in12, for example at various intensities. Additionally, the orientation of the battery170in the battery compartment (reference20inFIG. 1) is provided as an input to the CPU144.

Still referring toFIG. 11, it is foreseen that the datalink transceiver150and its associated antenna152are used to establish and communicate in the 915 MHz band via the datalink connection (reference50inFIG. 9) with other SMART beacons as in10. In order to address a given SMART beacon as in10via the datalink50, each SMART beacon10is provided with a unique identification, for example stored in ROM/RAM148, or hardwired for example into the datalink transceiver150. In this regard, the SMART beacons, via the datalink transceiver150and its associated antenna152, are able to communicate with other SMART beacons as in10which are not directly within range via other intermediary SMART beacons as in10. As the SMART beacons as in10are typically foreseen for use in a dispersed group setting in a generally localized area, this allows the transmission power of any particular transmission to be minimized, which has the dual benefit of saving power and limiting discovery, while allowing for communications to reach SMART beacons as in10which otherwise would not be within each others range.

In the alternative embodiment herein described, the modes of operation and channel selection of the SMART beacon10is substantially the same as that discussed hereinabove with reference toFIGS. 3A and 3Band TABLE 1. Additionally, in the transmission mode the SMART beacon10is able, for example, to transmit its current position and other data collected via the one or more physiological sensors (reference120inFIG. 9) to other SMART beacons as in10.

Referring back toFIG. 9, as discussed above a personal computer, smart phone or the like124may be tethered to a particular SMART beacon10using the WPAN122, thereby allowing data transmitted between the various SMART beacons as in10to be received by the smart phone124for additional processing. Referring now toFIG. 12, an exemplary smart phone124is illustratively equipped with a display154and software for displaying a map156onto which icons as in158representing the position of the SMART beacons are displayed. Movement of the cursor160over one of the icons is illustratively used as a command to provide detailed information162associated with that particular icon/SMART beacon. Additionally, the shape, color and behavior of the icon could be selected to coordinate with the particular status of the icon. For example, if data collected from the one or more physiological sensors (reference120inFIG. 9) indicate that the wearer of the SMART beacon is in distress, then the behavior icon (for example a color change or placed in a flashing mode) as displayed on the display154could be changed to provide a visual cue to this effect. Additionally, GPS and inertial guidance data can be used be processed in order to derive a direction of movement or the like.

Still referring toFIG. 12, in an additional scenario the color of the icons as in158as well as their behavior can be coordinated with the actual color and behavior of the particular SMART beacons they represent. For example, a red flashing SMART beacon can be displayed as a red flashing icon158on the display154. This can be based either on data received from the SMART beacon indicating its current mode of operation, or control data sent from the smart phone to the SMART beacon based on inputs or configurations selected by the user of the smart phone. The smart phone could also be used to selectively or globally change the color and behavior of each or all the SMART beacons simultaneously.

Referring now toFIG. 13, a clustered beacon system, general referred to using the reference numeral164, and in accordance with a second alternative illustrative embodiment of the present invention will be described. The system164comprises a plurality of portable beacons10, for example attached to a life jacket or the like (not shown), which upon activation emit light flashes166according to a predetermined signature. Each of the beacons10further comprises a range166within which it is able to communicate and exchange data with another of the beacons as in10. In accordance with one illustrative embodiment of the present invention, beacons as in10Awhich are within range of one another communicate and exchange data such that they emit light flashes166which are synchronized with one another, and typically according to the same signature.

Still referring toFIG. 13, for example in an illustrative embodiment the beacons10are attached to life jackets worn by individuals and activated once the individual enters the water. In this regard, and referring back toFIG. 1, the beacon10is illustratively equipped with a water activated switch168such that the at least one LED12commences emitting light according to a predetermined or selected signature automatically once water is entered.

Referring now toFIG. 14, illustratively the electronics of the second alternative illustrative embodiment of the beacon10comprise a controller (CPU)170as well as ROM/RAM172for storing software programs and data and the like. The controller170receives inputs via the rotary switch18, the water activated switch168and the transceiver174and, according to data stored within the ROM/RAM172, drives the one or more LEDs12via an LED driver interface176. A system clock178is provided in order to ensure correct timing of the electronics. In particular, the transceiver174is used to exchange, using an appropriate communications protocol, synchronization data.

Still referring toFIG. 14, in a particular embodiment a GPS module180is provided in order to determine the location of the light emitting beacon10as well as provide a universal time signal, which, as will be discussed in more detail below, is illustratively used by the system clock178in order to maintain a universal synchronization. Additionally, in a particular embodiment, the transceiver174can be a wireless RF transceiver using WiFi, Bluetooth or the like. Additionally, the wireless RF transceiver could include the ability to build adhoc or mesh networks with other beacons within range such that beacons within range of other “out of range” beacons can be used as a communication relay to reach those beacons. Alternatively, the transceiver174could be a line-of-sight wireless transceiver such as an infrared transceiver or the like.

Referring now toFIG. 15in addition toFIG. 14, each beacon10illustratively comprises control data stored in ROM/RAM172for illuminating the one or more LEDs12according a plurality of signatures as in182. Each signature as in182comprises periods of time during which a particular LED as12is illuminated or is not illuminated (as indicated inFIG. 15in reference to signature S3) over a predetermined time interval, illustratively twenty (20) seconds. Following the expiration of the given time period, the sequence merely repeats in order to generate an indicated signature over an extended period of time. Illustratively sixteen (S1through S16) signatures are provided.

A signature comprises not only the relative position and length of the periods within which the one or more LEDs as in12are illuminated, but also, through repetitions, the frequency at which the particular sequence is played. For example the well known SOS Morse code can be played at a first frequency by selecting S1and a faster frequency (twice as fast) by selecting S2. Alternatively, referring to S3, S4, S5and S6it may be wished to have an equally spaced sequence of flashes played at different frequencies, for example 0.5 Hz (S3), 1 Hz (S4), 2 Hz (S5), 4 Hz (S6) and so on. In order to accommodate each of these a separate signature is required. In still another embodiment, and referring to S7through S15it may be wished that a plurality of synchronized beacons as in10illuminate at different periods in time, for example in order to provide a moving strobe effect, such as used in airport runways and the like, and for example in order to indicate direction. Additionally, and referring to S16, other more general sequences can be preprogrammed and subsequently selected in order to provide a wanted effect.

Still referring toFIG. 14andFIG. 15, in operation the starting time of any signature is controlled according to the system clock178as well as synchronization data received at a given beacon10from other beacons as in10within range via the transceiver174using an appropriate communications protocol. Synchronization data could include, for example, a point in time when all beacons as in10within range should commence illumination, signature to be used, position data and the like. Illustratively, the GPS module180can be used to provide ongoing updates to the system clock178in order to ensure that the system clocks178of all the beacons as in10remain synchronized with one another.

As discussed above, the predetermined time interval after which a signature is repeated is illustratively 20 seconds. In practice, the predetermined time interval is typically selected long enough such that a number of different signatures can be easily accommodated within the time period, yet short enough such that differences in the speed of the system clocks178of different beacons10has little or no effect. Provided each of the beacons as in10are synchronized to restart a particular signature at substantially the same moment of time, the entire group of beacons will maintain synchronization and appear, for example, to flash as one to give the effect of one large single light source.

In a particular embodiment, beacons as in10could initially illuminate according to a predetermined signature at a random starting point in time. As subsequent beacons as in10come into range they would be resynchronized such that the signature is commenced at the same time, thereby providing a visual clue that a given beacon as in10is within range of another beacons or group of beacons.

While this invention has been described with reference to the illustrative embodiments, this description is not intended to be construed to a limiting sense. Various modifications or combinations of the illustrative embodiment of the invention will be apparent to persons skilled in the art upon reference to the description. It is therefore intended that the described invention encompass any such modifications or embodiments.