Interior positioning system for tracking communication devices within a remote location, and method therefore

There is described an interior positioning system for tracking spatial position of communication devices within a remote location. The interior positioning system generally has: a radio frequency network distributed through said remote location; beacons spaced-apart from one another throughout said remote location and powered by said radio frequency network, each beacon locally emitting a corresponding beacon identifier which when received by a nearby communication device is communicated over said radio frequency network by said communication device; and a tracking controller being communicatively coupled to said radio frequency network, said tracking controller stored thereon tracking data associating each of said beacon identifiers to respective spatial coordinates, and instructions that when executed perform the steps of: receiving said beacon identifier communicated over said radio frequency network by said communication device, and determining spatial coordinates of said communication device by cross referencing said received beacon identifier to said tracking data.

FIELD

The improvements generally relate to tracking position(s) of one or more communication devices within a remote location, and more particularly relate to the tracking of communication device(s) moving within a location where traditional wireless network signals and GPS signals are not accessible.

BACKGROUND

Tracking the position of a communication device, such as a smartphone, an electronic tablet and the like, moving within an underground mine, an isolated plant, a building interior and any other remote location is useful not only to track the communication device itself but also track an operator, a vehicle or a piece of equipment carrying the communication device. As such, in case of an incident within the remote location, interior positioning systems are used to retrieve which communication devices were positioned near the incident, which is of great interest should an operator be rescued, for instance. Such communication device tracking presents challenges as traditional wireless network signals and GPS signals may not be as reliable in such remote locations as they would be in the outside world. Although existing systems for tracking communication devices within a remote location are satisfactory to a certain degree, there remains room for improvement, especially in facilitating the maintenance of such systems and/or avoiding battery-related issues.

SUMMARY

It was found that there is a need in the industry to provide an interior positioning system which maintenance is facilitated and/or does not rely on battery-powered beacons.

In some aspects of the present disclosure, there are described an interior positioning system and method for tracking spatial position of communication devices within a remote location. The interior positioning system has a radio frequency network distributed through the remote location, beacons spaced-apart from one another throughout the remote location and along the radio frequency network, and a tracking controller communicatively coupled to the radio frequency network. Each of the beacons locally emits a corresponding identifier which when received by a nearby communication device is communicated over the radio frequency network by the communication device. The tracking controller has access to tracking data associating each of said identifiers to respective spatial coordinates. As such, the tracking controller can receive the identifier communicated over the radio frequency network by the communication device, and determine spatial coordinates of the communication device by cross referencing the received identifier to the tracking data. It was found convenient to power the beacons by the radio frequency network. As a result, maintenance of the interior positioning system is facilitated and its reliability is increased as the risk of having a battery-related failure close to an incident is greatly reduced.

In accordance with a first aspect of the present disclosure, there is provided an interior positioning system for tracking spatial position of communication devices within a remote location, the interior positioning system comprising: a radio frequency network distributed through said remote location; a plurality of beacons spaced-apart from one another throughout said remote location and powered by said radio frequency network, each of said beacons locally emitting a corresponding beacon identifier which when received by a nearby communication device is communicated over said radio frequency network by said communication device; and a tracking controller being communicatively coupled to said radio frequency network, said tracking controller having a processor and a memory having stored thereon tracking data associating each of said beacon identifiers to respective spatial coordinates, and instructions that when executed by said processor perform the steps of: receiving said beacon identifier communicated over said radio frequency network by said communication device, and determining spatial coordinates of said communication device by cross referencing said received beacon identifier to said tracking data.

Further in accordance with the first aspect of the present disclosure, said beacons can for example be battery-less.

Still further in accordance with the first aspect of the present disclosure, said radio frequency network can for example have a communication link carrying a communication signal, and a powering link supplying electrical power to said beacons.

Still further in accordance with the first aspect of the present disclosure, said powering link can for example include a power injector injecting said electrical power to said communication signal.

Still further in accordance with the first aspect of the present disclosure, said power injector can for example inject a direct current power supplying component to said communication signal.

Still further in accordance with the first aspect of the present disclosure, said direct current power supplying component can for example include a negative tension.

Still further in accordance with the first aspect of the present disclosure, said negative tension can for example be below at least minus 5 VDC.

Still further in accordance with the first aspect of the present disclosure, at least one of said beacons can for example have a power supplying port for supplying power to at least one of said communication device an external device.

Still further in accordance with the first aspect of the present disclosure, said beacons can for example have an operating software being updatable via said radio frequency network.

Still further in accordance with the first aspect of the present disclosure, said updating can for example be performed by modulating a power supplied by said radio frequency network.

Still further in accordance with the first aspect of the present disclosure, said radio frequency network can for example have a leaky cable interspersed throughout said remote location, each of said beacons being within a radiating range of said leaky cable.

Still further in accordance with the first aspect of the present disclosure, said radio frequency network can for example have a plurality of radio frequency antennas distributed within said remote location, each of said beacons being within a radiating range of at least one of said radio frequency antennas.

Still further in accordance with the first aspect of the present disclosure, at least a given one of said beacons can for example have a processor and a memory having stored thereon instructions that when executed by said process perform the steps of: upon detecting that said given beacon is no longer in communication with said radio frequency network, generating an alert which when received by a nearby communication device is communicated over said radio frequency network by said communication device.

In accordance with a second aspect of the present disclosure, there is provided a method of tracking position of communication devices within a remote location having a radio frequency network distributed therethrough, the method comprising: using a plurality of beacons spaced-apart within said remote location, drawing power from said radio frequency network and, using said drawn power, locally transmitting corresponding beacon identifiers nearby; upon a communication device receiving at least one of said locally transmitted beacon identifiers, communicating said received beacon identifier via said radio frequency network; and using a tracking controller, accessing tracking data associating each of said beacon identifiers to respective spatial coordinates; receiving said beacon identifier communicated over said radio frequency network by said communication device; and determining spatial coordinates of said communication device by cross referencing said received beacon identifier to said tracking data.

Further in accordance with the second aspect of the present disclosure, said radio frequency network can for example communicate with said beacons by modulating said power.

Still further in accordance with the second aspect of the present disclosure, said radio frequency network can for example have a communication signal and a powering signal superposed to said communication signal.

Still further in accordance with the second aspect of the present disclosure, said powering signal can for example include a direct current power supplying component, said direct current power supplying component having a negative tension.

Still further in accordance with the second aspect of the present disclosure, the method can for example further comprise, upon detecting that a given one of said beacons is no longer in communication with said radio frequency network, generating an alert which when received by a nearby communication device is communicated over said radio frequency network by said communication device.

Still further in accordance with the second aspect of the present disclosure, upon communicating said received beacon identifier via said radio frequency network, said communication device can for example further communicate a device identifier identifying said communication.

Still further in accordance with the second aspect of the present disclosure, upon communicating said received beacon identifier via said radio frequency network, said communication device can for example further communicate sensor data indicative of data generated by a sensor of at least one of said communication device and an external device communicatively coupled to said communication device.

DETAILED DESCRIPTION

FIG.1shows an example of an interior positioning system100for tracking spatial position of communication devices10within a remote location102. As depicted in this specific embodiment, the remote location102is provided in the form of an underground mining infrastructure103, including tunnel(s)104at different depth(s) within the ground106. However, in some other embodiments, the remote location102can be provided in the form of any other remote location having limited access to traditional wireless network signals and/or GPS signals such as isolated plants, building interiors, airports and the like.

The communication devices10to be tracked can vary depending on the embodiment. For instance, the communication devices10may be provided in the form of a smart phone10a, an electronic tablet10b, an electronic watch, a modem, a device having one or more communication interfaces (e.g., a LTE communication interface, a Bluetooth Low Energy (BLE) communication interface) and the like. In some embodiments, the communication devices10are dedicated devices which are to be part of wearable devices such as helmets, cap lamps, gloves, or other types of body-worn garments. In some other embodiment, the communication devices10are mountable to assets such as vehicles, tool boxes and the like, which can allow to track costly and/or useful assets within the remote location102.

As shown, the interior positioning system100has a radio frequency network110distributed through the remote location102. In some embodiments, the radio frequency network110is an Long-Term Evolution (LTE) cable network. Examples of a radio frequency network110can include, but not limited to, a cellular communication network of the first generation (1G), a cellular communication network of the second generation (2G), a cellular communication network of the third generation (3G), a cellular communication network of the fourth generation (4G), a cellular communication network of the fifth generation (5G) and any following cellular communication network generations. The radio frequency network110can be operated within any suitable frequency band including, but not limited to, any suitable 3GPP defined LTE band and the like. In this specific embodiment, the radio frequency network has one or more leaky cables112interspersed throughout the remote location102. As depicted, the leaky cable112can include a coaxial cable with gaps in its outer conductor to allow radio signals to leak in or out of the cable along at least a portion of its length. The leaky cables112may be removably or permanently attached to roof portions, wall portions and/or floor portions of the tunnels depending on the embodiment.

The interior positioning system100has a plurality of beacons114which are spaced-apart from one another throughout the remote location102and powered by the radio frequency network110. As such, in some embodiments, the beacons114are battery-less. Each beacon114locally emits a corresponding beacon identifier116which when received by a nearby communication device10is communicated over the radio frequency network110by the communication device10. The beacon identifier116can be communicated via a radio frequency signal in some embodiments. In some other embodiments, the beacon identifier116can be communicated via a wireless signal such as a BLE signal. Wi-Fi may also be used for this type of communication in some alternate embodiments. In some alternate embodiments, the beacon identifier116can be wiredly communicated to the communication device10upon connecting a cable between the beacon114and the communication device10. In these embodiments, the beacon identifier115can be communicated by modulating power supplied via one of its power supplying ports. The communication devices10may have hardware and/or software implementations configured to allow the communication devices10to communicate, unidirectionally or bi-directionally, with any one of the beacons114. For instance, in embodiments where the communication device10is provided in the form of a smartphone10a, the communication may be facilitated via a downloadable software application. As depicted in this embodiment, each of the beacons114are within a radiating range of the leaky cables112to communicate therewith.

As illustrated, the interior positioning system100has a tracking controller118which is communicatively coupled to the radio frequency network102. The tracking controller118has a processor and a memory having stored thereon tracking data associating each of the beacon identifiers116to respective spatial coordinates of the remote location102. The spatial coordinates can be expressed in terms of (xi, yi, zi) coordinates within a given coordinate system (x, y, z) in some embodiments. The spatial coordinates can be expressed in terms of longitude, latitude and altitude coordinates in some other embodiments. Additionally or alternatively, the spatial coordinates can be expressed in terms of sectors, sections, and/or areas of the remote location102. However, it is noted that any suitable type of spatial coordinates can be used as may be apparent to the skilled reader. The tracking controller118can have instructions to receive the beacon identifier116communicated over the radio frequency network110by the communication device10, and to determine spatial coordinates of the communication device10by cross referencing the received beacon identifier116to the tracking data. As will be detailed below, the tracking controller118may receive a device identifier along with the beacon identifier116so as to identify which one of the communication devices10has communicated that beacon identifier116, which can be convenient when a plurality of communication devices10are to be tracked simultaneously or sequentially. It is noted that the tracking controller118may receive a timestamp along with the beacon identifier116and/or the device identifier so as to identify when the communication device10has received and/or communicated that beacon identifier116, which can in turn enable the tracking of the communication device10over time.

The tracking controller118can be provided as a combination of hardware and software components. The hardware components can be implemented in the form of a computing device200, an example of which is described with reference toFIG.2. Moreover, the software components of the tracking controller118can be implemented in the form of a software application implementing method steps, a flow chart300showing some of these method steps is described with reference toFIG.3.

Referring toFIG.2, the computing device200can have a processor202, a memory204, and I/O interface206. Instructions208for determining the position of one or more communication device can be stored on the memory204and accessible by the processor202.

The processor202can be, for example, a general-purpose microprocessor or microcontroller, a digital signal processing (DSP) processor, an integrated circuit, a field programmable gate array (FPGA), a reconfigurable processor, a programmable read-only memory (PROM), or any combination thereof.

Each I/O interface206enables the computing device200to interconnect with one or more input devices, such as keyboard(s), mouse(s), or with one or more output devices such as display screen(s), memory system(s) and external network(s).

The computing device200and the software application described herein are meant to be examples only. Other suitable embodiments of the tracking controller118can also be provided, as it will be apparent to the skilled reader. For instance, the tracking controller118may be provided in the form of a physical server, a virtual server, or a combination of both.

FIG.3is a flow chart of an example method300of tracking position of communication devices within a remote location with a radio frequency network distributed therethrough. The method300is described with reference to the interior positioning system100ofFIG.1for ease of reading.

At step302, power is drawn from the radio frequency network110at a plurality of locations within the remote location102and, using the drawn power, beacon identifiers116are locally transmitted around each one of these locations. More specifically, each of the beacons114draws its power directly from the radio frequency network110and emits a corresponding beacon identifier116within a given radiating range therearound.

At step304, upon one of the communication devices10receiving at least one of the locally transmitted beacon identifiers116, the received one of the beacon identifiers116is communicated with the radio frequency network110.

At step306, the tracking controller118accesses tracking data associating each of the beacon identifiers116to respective spatial coordinates within the remote location102.

At step308, the beacon identifier116communicated over the radio frequency network110by the communication device10in step304is received by the tracking controller118.

At step310, the tracking controller118determines spatial coordinates of the communication device10by cross referencing the beacon identifier116received at step308to the tracking data accessed at step306.

It is noted that the order in which these steps are performed is exemplary only. For instance, although method300shows that step306is performed prior to step308in this embodiment, step306can equivalently be performed after step308in some other embodiments. Allowed permutations of the method steps described herein will be apparent to the skilled reader.

In some embodiments, the radio frequency network100has a communication link carrying a communication signal and a powering link supplying a power signal. In some embodiments, the power signal supplied by the powering link is superposed to the communication signal. The communication signal can be used to communicate beacon identifiers and device identifiers from the communication device to the tracking controller118. The communication signal can also be used to carry information from the tracking controller118to the beacons114and/or to the communication devices10. For instance, the communication signal can include information used to update firmware or an operating software of at least some of the beacons114. Additionally or alternatively, information may be carried to the beacons114by modulating the power supplied by the powering signal. As such, the powering signal may be used to communicate as well. However, in these embodiments, high speed communication (e.g., using LTE communication protocols) may preferably be performed through the communication link whereas low speed communication may be performed through the powering link.

In some embodiments, the powering signal includes a direct current (DC) power supplying component. It was found convenient to provide the DC power supplying component with a negative tension which may protect portions of the radio frequency network110, and more specifically its leaky cable112, from corrosion. The DC power supplying component may be below minus 12 VDC, below minus 24 VDC, or even below minus 48 VDC depending on the embodiment. It is envisaged that the DC power supplying component may range between minus 5 VDC and minus 60 VDC in some embodiments.

In some embodiments, the method300includes an optional step in which, upon detecting that a given one of the beacons114is no longer in communication with the radio frequency network110, generating an alert which when received by a nearby communication device10is communicated over the radio frequency network110by the communication device10. As such, if it is detected that the radio frequency network110has a broken link somewhere, the generated alert can indicate which portion, and preferably between which of the beacons114, the radio frequency network110is in fact damaged or otherwise not functional. Accordingly, such a step can allow rapid and precise maintenance of the radio frequency network110, when necessary.

FIG.4shows an example of the underground mining infrastructure103, taken along section4-4ofFIG.1. As shown, this particular level of the underground mining infrastructure103is provided in the form of a gallery having a number of tunnels104and pillars122. In this specific embodiment, two leaky cables112are interspersed within the tunnels104in a manner which cover all tunnel portions with the radio frequency network110. Also shown in this embodiment are a number of beacons114which are strategically positioned on the corners A, B, C, . . . N of the pillars122.

As best shown inFIG.5A, the beacons114are positioned so as to be in range of the radio frequency network110in order to draw power124from the radio frequency network110, and more specifically from one of the leaky cables112, at all times. The so-drawn power124is used to locally emit corresponding beacon identifiers116. For instance, beacon A may transmit beacon identifier A, beacon B may transmit beacon identifier B, and so forth. It is expected that the beacon identifiers116are unique with respect to one another, otherwise they would not suitably identify their corresponding beacon114.

When a communication device10is in close proximity to a given one of the beacons114, such as shown inFIGS.4and5B, the communication device10receives the corresponding beacon identifier116, in this case the beacon identifier E of the beacon positioned at corner E of the remote location102, and communicate it over to the tracking controller118via the radio frequency network110. As shown specifically inFIG.5B, the communication device100can communicate a device identifier130identifying the communication device10as well. Communicating the device identifier130may be convenient in situations where a plurality of communication devices10are to be tracked at once. It is noted that the communication device10may communicate a timestamp identifier132along with the beacon identifier116and/or the device identifier130so that the tracking controller118can identify at what time the communication device10has received and/or communicated that beacon identifier116, which can in turn enable the tracking of the communication device10over time. In addition, the communication device10may communication sensor data134along with the other identifiers. The sensor data134may include data provided by one or more on-board sensors such as gyroscope(s), accelerometer(s), yaw sensor(s), pressure sensor(s), temperature sensor(s), and the like. In some embodiments, the communication device10is in communication with a diagnostic port of an engine control unit (ECU) of a vehicle to retrieve sensor data including instantaneous speed of the vehicle, GPS position and the like. In these embodiments, the diagnostic port of the engine's ECU may be provided in the form of a J1939 port to which the communication device10is wiredly connected via a CAN bus link. Such data may be processed to monitor direction, vibration, shock, temperature, surrounding gas content, and any other measurands, associated with the communication device10at any time. For example, in an embodiment, accelerometer data can be monitored to track the speed of a truck moving within the remote location102for safety purposes. In another embodiment, topography of the remote location102may be monitored for maintenance purposes. In some embodiments, the communication device10can communicate sensor data originating from one or more sensors of one or more of the beacons114. For instance, some of the beacons114may have sensors monitoring ambient temperature, line voltage or any other suitable measurand, all of which may be communicated to the communication device10along with the corresponding beacon identifier116for subsequent communication to the radio frequency network110.

Referring now toFIG.5C, upon the tracking controller118receiving the beacon identifier116and the device identifier130from the radio frequency network110, the tracking controller118is configured to determine the spatial coordinates136of the communication device10based on tracking data138associating beacon identifiers to a plurality of different spatial coordinates of the remote location102. Computations within the tracking controller may be performed using a tracking module140, in some embodiments. Once determined, the device spatial coordinates136can be displayed or otherwise shared with a graphical user interface, an open platform communications network, a network operations center or a monitoring system, depending on the embodiment.

FIG.6shows example tracking data600, in accordance with an embodiment. As shown in this embodiment, the tracking data600is provided in the form of a look-up table602having a column indicating beacon identifiers116and another column indicating spatial coordinates136. Each row of the loop-up table indicates a pair of corresponding beacon identifier116and spatial coordinates136. In this way, once a beacon identifier116is received from the radio frequency network110, the tracking controller118finds the received beacon identifier116within the look-up table602, and thereafter finds the spatial coordinates136associated thereto and then associate it to the device to be tracked. The tracking data600may not be in the form of a look-up table in some other embodiments.

Depending on the embodiment, the beacons may not all be similar to one another. For instance, in some embodiments, beacons that are meant to be positioned at intermediate positions along the radio frequency network may be provided in the form of intermediary beacons700, an example of which is shown inFIG.7, whereas beacons that are meant to terminate a given leaky cable, or be farther down the remote location, may be provided in the form of a termination beacon800, an example of which is shown inFIG.8.

FIG.7shows an example intermediary beacon700. As shown, the intermediary beacon700has a frame702enclosing a power drawing module704and an identifier emission module706. The power drawing module704is configured to draw power from the radio frequency network as discussed above. The identifier emission module706is configured to locally emit a given identifier116which may be predetermined or set when the intermediary beacon700is manufactured. It is noted that the power drawing module704and the identifier emission module706can be embodied by a controller-type device having a processor and executable instructions stored on a memory accessible by the processor. As shown in this example, the intermediary beacon700can have one or more power supplying ports708for supplying power to one or more devices. For instance, the power supplying ports708can include ports of different types to power different communication devices10or any other external device (e.g., electrically powered tools, battery chargers, cameras), which may be convenient for workers working in the remote location. In some embodiments, the intermediary beacon700, or any other beacon described herein, can be powered using a direct current power supplying component of minus 48 VDC at less than 100 mA or preferably less than 50 mA. However, should an external device be connected to one of the power supplying ports708, electrical consumption can go up to about 2 A, in some specific embodiments.

FIG.8shows an example termination beacon800. As depicted in this embodiment, the termination beacon800has a frame802enclosing a power drawing module804, an identifier emission module806and also an alert generation module808. Similarly to the intermediary beacon700, the power drawing module804is configured to draw power from the radio frequency network whereas the identifier emission module806is configured to locally emit a given identifier116which may be predetermined or set when the termination beacon800is manufactured. In addition, the alert generation module808may be configured to monitor a status of the radio frequency network as perceived by the termination beacon800. Should the status may not be deemed satisfactory, the alert generation module808can generate an alert814indicating that the radio frequency network is not satisfactory at that location. The alert814can be received by a nearby communication device which may forward it to the tracking controller, or any other type of controller, via the radio frequency network once that communication device is moved in a region of satisfactory radio frequency network status elsewhere within the remote location. The alert814may cause an indicator such as a visual or an auditory indicator to be activated. The alert814may be stored on a memory system and/or transmitted otherwise to an external network upon reception. The alert814may trigger maintenance of the radio frequency network, and more specifically, maintenance of the faulty region of the radio frequency network as monitored by the termination beacon800. In some embodiments, the termination beacon800has a radio frequency termination load to avoid undesirable reflection of the radio frequency signal back along the leaky cable.

It is envisaged that the termination beacon800may be strategically used as an end of line module, specifically aimed at monitoring whether the radio frequency network is accessible at the corresponding end of line location. However, the termination beacon800may be used elsewhere within the remote location. For instance, the termination beacon800may be used at branch locations where one or more communication lines separate from one another.

FIG.9shows another implementation of a radio frequency network910in a remote location. In this specific embodiment, the radio frequency network910has a number of coaxial cable901carrying communication and powering signals to a number of radio frequency antennas902distributed within the remote location, with each of the radio frequency antennas902emitting the communication and powering signals therearound within a respective radiating range and receiving communication signals from surrounding communication devices10. As shown, each of the beacons114are within range of one or more radiating ranges of at least some of the radio frequency antennas902. This type of network architecture may be referred to as a distributed antenna system (DAS). It is envisaged that the radio frequency network described herein may be provided in the form of one or more leaky cables, one or more distributed antenna systems, and any combination thereof, depending on the embodiment.

Referring now toFIG.10, there is shown an interior positioning system1000, according to one or more embodiments. The interior positioning system1000may also be referred to as a network tracking engine (NTE) or a real-time location system (RTLS). The interior positioning system1000is preferably used to track the position of at least one communication device1004in a remote location or in an underground location such as an underground mine in which traditional means for position tracking such as Global Positioning System (GPS) would not function as the signal would be weak or non-existent.

The interior positioning system1000includes a radio frequency network, preferably an LTE cable network1006(also referred to as an LTE transport network) including at least one leaky cable1008interspersed throughout the underground mine. In an alternate embodiment, an existing Wi-Fi network (not shown) may be used in place of the LTE cable network1006, if available. A leaky cable can include a coaxial cable with gaps or slots in its outer conductor to allow radio signals to leak in or out of the cable along its entire length. As such, the LTE cable network1006can receive information transmitted by the at least one communication device1004to the at least one leaky cable1008. Preferably, each mine worker working in the underground mine would carry a communication device1004so that their position may be tracked in real-time to ensure their safety and facilitate communication. Alternatively, communication devices1004may be installed in vehicles traveling through the mines. In another embodiment, the interior positioning system1000may be used to perform asset tracking with a non-geolocalized BLE beacon1010.

Still referring toFIG.10, a plurality of beacons1010are installed along the LTE cable network1006and are powered by the LTE cable network1006. Alternatively, in another embodiment, each beacon1010is powered by an internal battery (not shown). This may be useful in case of a leaky link failure, for instance. Each beacon1010includes a unique beacon identifier and is configured to transit its unique beacon identifier to a nearby communication device1004. In addition, the LTE cable network1006is connected to a data core1012which includes a tracking database (not shown) which includes information relating to the beacons1010. In particular, the tracking database includes a unique set of geographical coordinates corresponding to each unique beacon identifier. As such, the LTE cable network1006can transmit a received beacon identifier from a communication device1004to the data core1012, and thus the position of the communication device1004can be determined by cross referencing the received unique beacon identifier with a corresponding unique set of geographical coordinates. The beacons1010may be configured to each emit an uninterrupted signal, and thus as the communication device1004passes throughout the underground mine it may constantly receive unique beacon identifiers from nearby beacons1010and transmit this information to the data core1012so that its position may be constantly trackable in real-time. This is advantageous compared to battery powered beacons which broadcast their signals less frequently to conserve their battery life. In another embodiment, each beacon1010may be configured for bidirectional communication, allowing them to both send and receive signals.

In an embodiment, the beacons1010are installed every fifty meters along the LTE cable network1006and are used as fixed check points to allow for real-time tracking of the communication devices1004. Stored in the tracking database is a combination of the unique beacon identifier and a set of geographical coordinates, for example of the (x, y, z) variety, for each individual beacon1010. As such, a beacon1010may easily be relocated throughout the mine tunnels by simply updating its geographical coordinates in the tracking database. In an embodiment, the signal emitted by each beacon1010is a Bluetooth Low Energy (BLE) signal. As discussed above, each beacon1010is powered by the LTE cable network1006, thus negating the need to provide batteries for the beacons1010. In an embodiment, each beacon1010is IP69-rated to prevent possible damage from liquid and dust.

In some embodiments, each communication device1004is a commercial smartphone1014with both LTE and Bluetooth capabilities. A mobile application may be installed on the smartphone1014to allow the beacon1010to receive BLE signals from the beacons1010and establish various LTE communications, for example communicate with the LTE cable network1006by transmitting LTE signals to a leaky cable1008. Thus, the mobile application may allow the smartphone1014to report unique beacon identifier's to allow for real-time positioning, read tracking sensors and establish LTE communication. The implementation of a commercial smartphone1014as a communication device1004is beneficial because most mine workers already own or are provided with a smartphone, so they would not have to carry around an additional device to become connected to the interior positioning system1000. The mobile application may also be installed on other traditional consumer electronics with LTE and Bluetooth capabilities such as a tablet computer (not shown) so that they may act as a communication device1004for the purposes of the interior positioning system1000.

In some embodiments, each communication device1004is a proprietary NTE device1016including both LTE/Wi-Fi (for example CAT-M1) and BLE chipsets so that it may communicate with both the beacons1010and the LTE cable network1006. NTE device1016may also include a variety of sensors for sensing various data. Preferably, each NTE device1016is dimensioned so that it may be packaged in a body-worn device of a typical mine worker such as a cap lamp (not shown). As such, the mine workers would not have to carry around an additional device as the NTE device1016is integrated into their typical equipment. The NTE device may either be powered by the cap lamp's existing battery or include its own battery. In other embodiments, the NTE device may be integrated in another piece of traditional mine working equipment.

In some embodiments, the data core1012may include an application programming interface (API) to perform various functions. The API may monitor and receive regular reports regarding its positioning and collected sensor data at specific time intervals. In an embodiment, unless differently specified through this API, in the time period between these regular reports, each communication device1004will only send positioning and sensor data to the data core1012when one or both of them have changed, thus increasing power and information transmission efficiency. In another embodiment, each communication device will broadcast data to the data core1012regardless of if it's position changes.

The data core1012can be configured to store the tracking information in a reliable and efficient data structure. As such, in an embodiment, the data stored in the data core1012may be divided into two types: static data and dynamic data. Static data is manipulated less frequently than dynamic data and may be configured by external input through an API. Examples of static data stored in the data core1012may include configurations for the communication devices1004, unique beacon identifiers, beacon coordinates, the number and identity of devices connected to the LTE cable network1006and any geographical references for location purposes. Conversely, dynamic data is reported by the communication devices1004and is considered read-only information and thus cannot be configured by external input. The data core1012receives the dynamic data from the communication devices1004at predetermined intervals for storage and indexing. Examples of dynamic data may include communication device1004status, positioning and sensor data.

It is anticipated that an operator may modify static data and read dynamic data by using an API command. Data from the data core1012may be shared through an API with, for example, a graphical user interface (GUI)1018, an open platform communications network (OPC)1020, a network operations center (NOC)1022, as well as various monitoring systems (not shown). In addition, a variety of modules may be implemented to perform various functions. A base module (not shown) may handle the data core1012's static and dynamic information as well as NTE infrastructure and history of LTE and BLE monitoring. For both data security and consistency purposes, the base module preferably is the only module that can directly access the data core1012. An OPC1020module may translate the base module functions for external OPC clients. A GUI1018module may offer a web-based interface to interact with the base module. Finally, an external module (not shown) may allow for integrations with third party solutions. In an embodiment, the API is based on the REST architecture using the HTTPS transport protocol, TLS 1.2 cryptography protocol with certificate, and username and password authentication. Both Radius and LDAP integrations may be supported. In addition, the API software may be hosted in the same machine as the data core1012or may be hosted on a dedicated machine (not shown) to increase reliability and performance.

The interior positioning system1000may be integrated with external third-party software to meet a customer's various requirements. An external API module is thus dedicated to interoperability and to expose the API base module to industrial automation interaction. A variety of examples of such integration will now be discussed. An integration between the interior positioning system1000and various third party mining software packages can give to the customer a centralized web portal with a 3D real time positioning of workers and equipment, Internet of Things (IoT) sensory data and monitoring, industrial automation, production planning and overview, remote machine control, video streaming and a mobile application with underground navigation system. The interior positioning system1000may further feed a third party tracking solution. The interior positioning system1000may further be integrated with an emergency broadcast system to communicate any dangers directly to the communication devices1004over the LTE cable network1006. A further integration with the OPC standard enables machine-to-machine interaction between the interior positioning system1000and the OPC devices1020for automation purposes. A custom interoperability design may add an NTE panel in the customer's NOC software1022to supervise, monitor and control both the LTE and BLE networks without changing the operation's work instruments. All of these examples may be designed to handle the interior positioning system1000's infrastructure efficiently and with minimum impact on the customer's infrastructure and tools.

Advantageously, each beacon1010may be positioned between two sections of the leaky cable1008of the LTE cable network1006so that the beacon1010may draw its power from the leaky cable1008rather than require its own power source. In addition, each beacon1010may include its own power output port, for example a two-pin connector interface, to provide power to external devices such as a communication device1004, a camera (not shown) or a sensor (not shown). In an embodiment, when firmware updates are available for the beacons1010, they may be sent to the beacons through the LTE cable network1006. In this embodiment, the power signal will be modulated to signal each beacon1010at first when an update is available, and then the firmware data will be transferred. Once the firmware update is complete, the power signal will return to its standard functional mode. In addition, the LTE signal on which each beacon receives power will preferably remain uninterrupted, whether it is being used to power the beacons1010or provide firmware updates. As such, any other devices using the LTE signal such as smartphones or other IoT devices will maintain an uninterrupted connection with the LTE cable network1006regardless of the beacons'1010operational modes.

With reference to the interior positioning system1000, there is describe a method for tracking the position of at least one communication device1004in an underground mine. An LTE cable network1006is installed including at least one leaky cable1008interspersed throughout the underground mind, the LTE cable network1006connected to a data core1012including a tracking database. A plurality of beacons1010are installed along the LTE cable network1006and are each powered by the LTE cable network1006and each emit a unique beacon identifier. A unique set of geographical coordinates corresponding to each unique beacon identifier are stored in the tracking database of the data core1012. The at least one communication device1004receives a unique beacon identifier from a nearby beacon1010and transmits the received unique beacon identifier to the data core1012via the LTE cable network1006. Then, the position of the at least one communication device1004is determined by cross referencing the received unique beacon identifier with a corresponding unique set of geographical coordinates.

Referring now toFIG.11, there is shown an interior positioning system1100, according to another embodiment. As depicted, the interior positioning system1100has a radio frequency network1102, a plurality of beacons1104powered by the radio frequency network1102and a network controller1106.

As shown, the tracking controller1106has a core database1108, a core processor1110, software applications1112and network communication module1114.

In this specific embodiment, the radio frequency network1102includes a remote radio unit (RRU)1116, a DC injector1118, and a combination of coaxial cable(s)1120, radio frequency antennas1122propagating a radio frequency signal towards a remote location, and leaky cable(s)1122radiating the radio frequency signal locally within the remote location. The DC injector1118can be configured to inject a direct current power supplying component having an output ranging between minus 5 VDC and minus 60 VDC, and more preferably of minus 48 VDC at less than 7 A output. The DC injector1118can be connected using a radio frequency cable in an inline manner with respect to the RRU. The DC injector1118can have short-circuit protector, and be compliant with industry locking and tagging policies.

At some point within the remote location, the leaky cables1122and/or antennas are provided to radiate the radio frequency signal at strategic locations within the remote location. In this specific embodiment, the RRU1116generates a radio frequency signal modulated to carry information in a communication signal. Power may be incorporated to the radio frequency signal using the DC injector1118, which incorporates a direct current power component to the radio frequency signal. For instance, the radio frequency signal may oscillated between predetermined voltage values at a frequency comprised within a given radio frequency bandwidth. The direct current power component may offset the voltage values by a given amount, thereby adding electrical energy to the radiated signal. In this specific embodiment, the direct current power component is used to power the beacons1104within the remote location.

In this embodiment, the beacons1104, including intermediary beacon(s)1104aand termination beacon(s)1104b, are provided within the remote location. Each of these beacons1104are powered by the radio frequency signal radiated by the radio frequency network1102, and emit corresponding beacon identifiers as discussed above. Different types of communication devices10including, but not limited to, Android and/or iOS powered smartphones10aor electronic tablets10b, LTE modems10cand10e, cap lamps10e, or any other type of dedicated communication devices which may be body-mounted or asset-mounted. In some embodiments, communication between the communication devices10and the radio frequency network1102is performed using LTE communication whereas communication between the communication devices10and the beacons1104is performed using BLE communication. However, any other type of radio frequency communication can be used depending on the embodiments.

As can be understood, the examples described above and illustrated are intended to be exemplary only. For instance, in some embodiments, the radio frequency network broadcasts a communication signal and a powering signal. In some embodiments, the communication signal and the powering signal are independent from one another. However, in some other embodiments, the communication signal and the powering signal may be entangled to one another. It is envisaged that the expression “remote location” is meant to encompass any type of locations which may not be satisfactorily covered by traditional wireless network signals and/or GPS signals. The scope is indicated by the appended claims.