WO2019218014A1

WO2019218014A1 - An emergency light and a wireless communications network

Info

Publication number: WO2019218014A1
Application number: PCT/AU2019/050461
Authority: WO
Inventors: Wen Hu; Walter Huang; Brian Cheney
Original assignee: WBS PROJECT H Pty Ltd
Priority date: 2018-05-15
Filing date: 2019-05-15
Publication date: 2019-11-21
Also published as: AU2019271417A1

Abstract

An emergency light, including a connection adapted for attachment to a building power supply, storage for electrical power that is adapted to be charged by the building power supply, a processor, and a wireless communication node, the wireless communications node being adapted to form a self-organising network with other nodes, and the network being accessible by other devices than the nodes. Also a wireless communications network.

Description

AN EMERGENCY LIGHT AND A WIRELESS COMMUNICATIONS

NETWORK

Technical Field

[0001 ] The present invention relates to the provision of data networks, particularly within buildings and the built environment.

Background of the Invention

[0002] It has become a widespread requirement for buildings, public spaces and other environments to provide access to data communications. One way in which this is provided is via cellular data networks. These are widespread, but typically do not penetrate well into larger buildings, and require users to maintain a carrier subscription. Another option is to use WiFi type networks. These are limited in range and number of users, and so require many nodes or routers to be provided in order to cover an entire building. WiFi typically does not penetrate common structures such as reinforced concrete well, further limiting its application outside limited, specified areas.

[0003] The Internet of Things (loT) is a growing concept, in which vast numbers of devices are able to connect, be controlled and transmit data, without in most cases human intervention. The growth of demand for devices forming part of the loT further drives demand for the provision of a data communications system within buildings. Most loT traffic is relatively low data rate, and yet requires network, which penetrates to the full depths and extremities of a structure. For example, in a typical high rise building, mechanical plant, water and power supply, and other utilities are ideally able to be monitored as part of the loT, and these services are typically located deep in the building, not located in the public areas typically serviced by WiFi. To use WiFi or cellular to provide complete loT data coverage within a building will require the installation of many specialised additional microcells, routers or systems. These in turn require their own data and power connections to be provided, which creates additional expense and complexity.

[0004] WO 2016124917 by Wijnnovate Ltd discloses a wireless control and sensing apparatus and method for an emergency lighting system, using a pre-existing wireless system to be in existence in the building.

[0005] It is an object of the present invention to provide an alternative data communications system, particularly for installation within built structures. Summary of the Invention

[0006] In a first broad form, the present invention uses some or all of the emergency lighting system in a building as nodes for a self organising communications system, for example a LoRa system.

[0007] According to one aspect, the present invention provides An emergency light, including a connection adapted for attachment to a building power supply, storage for electrical power which is adapted to be charged by the building power supply, a processor, and a wireless communication node, the wireless communications node being adapted to form a self-organising network with other nodes, and the network being accessible by other devices than the nodes. In some implementations, the nodes may be LoRa devices, and operate in a mesh implementation. This further allows for remote and automated testing and monitoring of the emergency light system in a building.

[0008] According to another aspect, the present invention provides a wireless communications network within a building, including a plurality of self-organising wireless nodes associated with an emergency light, each emergency light being connected to the building power system and including a processor for controlling the wireless node.

[0009] It will be understood that according to implementations of the present invention, the lights are not merely connected to a network - they cooperate to generate the network, and self-organise to do so. No pre-existing WiFi or other network is required, and no data infrastructure is required for the network for provide loT connections throughout the building structure. The wireless network may include other wireless nodes, such as sensors, other equipment, or controlled valves, switches, etc.,. To provide the wireless communication, some or all of the nodes may provide other means of wireless communication such as Wi-Fi or Bluetooth, in addition to the self - organising network, which will facilitate convenient operation and monitoring with smartphones and differently enabled devices.

[0010] It will be appreciated that implementations of the present invention allow for a wireless network to be installed, without requiring any extra work in wiring or installation, relative to simply installing a regular emergency lighting system. Each emergency light must in any case be connected to mains power and have an associated battery back-up and control system. Emergency lights are generally required to cover the entire accessible spaces within a building, and so the network covers even plants rooms and similar deep structures in a building. By incorporating the network nodes into the emergency lights, a data network, for example for loT applications, can be readily and efficiently provided. By having the network nodes form a self-organising network, the nodes simply activate and come into operation as the lights are installed and connected. Brief Description of the Drawings

[001 1 ] An example of the present invention will now be described with reference to the accompanying figures, in which:

[0012] Figure 1 shows a general overview of a building communication system using emergency lights;

[0013] Figure 2 is a schematic block diagram of the components of a emergency light according to one implementation of the present invention;

[0014] Figure 3 illustrates the overall structure of a network according to one implementation of the present invention;

[0015] Figure 4 illustrates a battery test procedure for use with an implementation of the present invention;

[0016] Figure 5 illustrates a factory test procedure for use with an implementation of the present invention; and

[0017] Figure 6 illustrates the overall appearance of one emergency light according to an implementation of the present invention; and

[0018] Figure 7 is a block diagram illustrating the flow of communications through the network according to an implementation of the present invention.

Detailed Description of the invention

[0019] The present invention will be described with reference to a specific implementation and using specific communications technologies. Flowever, it will be understood that the invention is not limited in scope to the use of these, and alternative technologies and implementations are possible, and indeed envisaged.

[0020] The present invention has particular application to built structures. For the purposes of the specification and claims, the term building is intended to have a wide meaning, to encompass any structure above or below ground. This includes, for example, industrial, residential and commercial buildings; shopping malls; tunnels, mines and other underground structures; bridges, pylons, and other above ground structures; and vehicles, for example motor vehicles, buses, ships (for example cruise ships and ferries) and aircraft. The present invention can be applied in principle wherever emergency or similar special purpose lighting is provided.

[0021 ] The term emergency lighting refers to a system for providing lighting in the event that power is lost within a building. In most building standards, this is a requirement for built structures, beyond freestanding dwellings. Emergency lights include exit lights, stairwell lighting, and emergency lights typically positioned in the ceiling. It will be appreciated that in, for example, a modern commercial office building there are hundreds or thousands of such lights.

[0022] There is a requirement for emergency lights to have a battery back up, so that they will operate for a period of time after the building power goes off. For example 90 minutes is a mandatory standard in Australia. The mandatory presence of such lights, with mains power connections, provides the present invention with significant efficiencies and advantages.

[0023] The implementation to be discussed uses a communications protocol called LoRaWan®, a wireless data communication technology, which uses license-free sub gigahertz radio frequency bands, and enables very long range transmissions as well as deep penetration into buildings. It provides functionality such as bi-directional communications, mobile operation and positioning. Spread spectrum coding provides a large set of channels, and depending upon the implementation chosen the data rate may vary from 0.3 kbps to 50 kbps. A network server, typically one per building in the envisaged implementation, manages the data rate and RF output of each device, using an adaptive data rate scheme. This acts to maximise network capacity, while minimising battery usage for battery-powered devices. Further detail on LoRaWan® is available at https://lora-aniance.ora/ and https://www.semtech.com/technoloav/lora.

[0024] A LoRaWan® network is typically configured as a star of stars topology. However, trials have determined that it is preferred for implementations of the present invention that a mesh network topology is used. In a mesh network, the nodes connect directly, dynamically and non-hierarchically to as many other nodes as possible and cooperate with one another to efficiently route communications around the network. This lack of dependency on one node allows for every node to participate in the relay of information. Mesh networks dynamically self-organize and self-configure, which reduces installation overhead. The ability to self-configure enables dynamic distribution of workloads, particularly in the event that a few nodes should fail. This in turn contributes to fault- tolerance and reduced maintenance costs. In the context of a building, nodes can dynamically route signals to accommodate changes in the environment and usage at different times of the day. [0025] LoRaWan® contemplates different classes of devices, largely based on the need to maximise limited battery life, for example for remote sensors. However, as the emergency lights are connected to mains power, there is no difficulty in using class C modes, as power is not a limiting factor in their operation. A particular advantage of implementation of the present invention is that the wireless network nodes always have an associated mains power supply, without any special additional work being required.

[0026] Figure 1 conceptually illustrates an implementation of the present invention. A building 10 has a ground floor 1 1 and an upper floor 12. Each floor has respective emergency lights, illustratively 20, 20A, 20B, 20C. These lights are connected to mains power, and additionally have an associated wireless network node. Thus, a wireless network is made available on each floor using the emergency light units.

[0027] Figure 2 is a block diagram of an implementation of an emergency light according to the present invention. It will be appreciated that there are many alternative lighting system implementations possible, and the specific detail of the operation of the emergency light as such is not a limitation on the scope of the present invention.

[0028] The emergency lamp 43 is powered by lamp inverter 45. This in turn is powered by the emergency light control circuit 40. Lamp inverter 45 also monitors the condition of the lamp, and indicates to emergency light control circuit 40 the condition of the lamp. Lamp 43 may be of any suitable type, but will typically be one or more LED units.

[0029] Emergency light control circuit 40 is also connected to battery charging circuit 47, which in turn is connected to the battery pack 49. This may be of any suitable re chargeable type. The battery charging circuit 47 receives DC from the AC/DC inverter 48, which is in turn connected to the building AC power supply 52. The battery charging circuit 47 also provides power to the emergency light control circuit 40. The emergency light control circuit 40 manages the charging and emergency light operation of the system, independent of the CPU>

[0030] Charge LED 44 indicates that the charging circuit is active and maintaining the charge in battery pack 49. Test button 46 is used to test operation of the lamp. MCU interface watchdog 41 provides an interface between the emergency light control circuit 40 and CPU 42.

[0031 ] CPU board 42 implements the firmware and software needed for testing and monitoring of the system, as well as having memory for storage of logs, messages, etc. It controls indicator LEDs 50, 51 which have a function in indicating the status of the emergency light unit. It also communicates with and controls LoRa radio module 60, Bluetooth module 70, and hence their respective antennae 61 , 71 . [0032] Figure 3 illustrates the topology and overall design of a network according to this implementation of the present invention. It shows that atan overall system level resides a cloud server, for example an Amazon Wen Services (AWS) virtual server 38. This is connected via a secure connection 31 to a specific loT gateway 37, which manages connectivity to the loT network provided according to this implementation. Third party building services apps 36 are connected via a secure connection 31 under the control of the A loT gateway 37, to ensure only authorised and controlled access can occur from outside the LoRa network.

[0033] The various self-organised LoRa devices, specifically the emergency lights 20 (only one shown for simplicity) connect via their peers to the gateway 37 using the LoRa mesh network connections 33.

[0034] The emergency lights, for example 20, have an additional Bluetooth module, for example a Bluetooth Low Energy module (BLE), so that (for example) users with smartphones can access the network established by the emergency lighting system. The BLE system can be used as a secondary communication medium that opens the network to other nodes or themselves. It can be seen that light 20 has a Bluetooth connection 32 to a smoke detector 35. It will be appreciated that a wide variety of additional devices may connect via the Bluetooth connection.

[0035] The extra facility may be provided on all or only selected lights. Similarly, it is possible that some emergency lights are not connected to the LoRa network, although this is not preferred.

[0036] Figure 7 illustrates the flow of possible communications through the various components of this implementation of the present invention. loT devices 60, 61 can communicate via Bluetooth low energy connections 62 with one or the various emergency light devices 63 forming the LoRa network in the building. This device 63 connects via the mesh network 64,

[0037] The mesh network is connected via gateway 65 to the external internet, and more specifically to a cloud service 66. The cloud interacts via an API with both own (WBS) and external applications, for example for building control and monitoring, and for testing and monitoring the operation of the lights 63.

[0038] The LoRa® implementation of the present invention using commercially available devices. For example, in the implementation described, a suitable device is a Semtech SX1276 radio transceiver and driver MCU using an STM8 microcontroller that provides configuration and serial interface with the LoRa radio. Of course, it will be understood that alternative devices and implementations are possible within the scope of the present invention.

[0039] The implementation described further contemplates some or each emergency light having a Bluetooth module (BLE), so that (for example) users with smartphones can access the network established by the emergency lighting system. The BLE system can be used as a secondary communication medium that opens the network to other nodes or themselves.

[0040] The BLE radio is designed to provide multiple interfaces for beacon location, asset tracking, Android / iPhone interface. In a preferred form, a secondary high bandwidth mesh network, for example based on Thread, (see

mesh network using LoRa®. BLE is not expected to cover the same range and have the same infrastructure penetration as LoRa radio, but due to the number and distribution requirements of emergency lighting, will enable a secondary mesh network to be formed over 2.4Ghz radio. Each node will have the capability to communicate over dual mesh networking topologies, BLE and LoRa. Thus, the BLE capacity is in addition to and not substitution for the LoRa network.

[0041 ] The emergency lights according to the present implementation may be installed and connected to mains as with any conventional emergency lighting system. The gateway unit is installed, and connected to a suitable Internet connection. Once this has occurred, the system may be brought into operation as follows. It will be appreciated that each node (and hence each light unit) has a unique 32 bit device identifier within the network, which is present in each data frame and allows the gateway and network server to individually address each node.

[0042] Each node includes an autonomous monitoring system that can initiate a self-test as required when there is no network connectivity or via an over the air scheduled initiation from the network that can be scheduled to start at some time in the future or ASAP. All events including the results of the self-tests are stored on the node awaiting confirmed delivery to the network database server. A user using a mobile phone may monitor and control the node status provided there is a privilege. In case of absence of available network, nodes clearly indicate their status on the exterior. For example, a specific colour or blinking pattern of LED may show the status.

[0043] The activated node can then be addressed by the corresponding network server. Each node also identifies other nodes in range. [0044] As each light unit is started up, the node will wait to receive a beacon signal from gateways and other nodes, for example those associated with the other emergency lights. After receiving a beacon signal, the node will update its neighbour table, and calculate the best route between any gateway and itself by taking radio quality and the distance between the gateway and itself into account. Each node may use any other nodes in range as helpers, so as to hop between nodes to provide the best link to the gateway. This enables the nodes to work around any network defects or disabled nodes, in a dynamic way.

[0045] It will be appreciated that a reasonably evenly distributed set of network nodes, such as is provided by a set of emergency lights units according to the present invention, will typically provide a particularly good base for a wireless network. The route selection is fully distributive which make the network more robust to failures. Finally, the node will broadcast the beacons periodically so that other nodes in the network may choose it as a communication helper. Each node maintains its neighbour and routing tables periodically to accommodate radio communication and network dynamics.

[0046] Each lighting unit, once operative and connected to the network as discussed, will then typically carry out a series of tasks, requested typically by the network server, or alternatively carried out autonomously. These include a check of the LED functions, battery health check, factory test, and store the results locally. These may be carried out automatically according to a schedule.

[0047] The network server is automatically sent the local logs of these tasks by the nodes whenever network communications are available.

[0048] It will be appreciated that a further advantage of the present invention over conventional emergency lighting systems is that the status of the lights, that is whether they are functional at all times if required (for example for Exit lights), can be remotely and automatically monitored. Further, a test of the system, to ensure that lights go on if the power is off, and that they stay on for the required period, can also be done remotely and automatically monitored for each light. The lights are connected to a data network, and this kind of low data requirement function and reporting can be readily and cheaply carried out.

[0049] Figure 4 illustrates an illustrative test procedure for the emergency light, to verify that the battery is functioning properly, for example that it is providing an appropriate voltage, that the lamp is receiving a suitable voltage, and that the battery is charging as required. The outcome from this procedure is stored, and the log is available on demand from the network server, for each node. [0050] Figure 5 illustrates a further test procedure, for initialising and controlling a full factory test procedure. Such a test may be undertaken either autonomously when the emergency light is connected and initialised; at regular intervals; or on command from the network server.

[0051 ] It will be appreciated that the details and exact test process will be particular to the model and design of each specific emergency light.

[0052] Figure 6 illustrates the physical appearance of one implementation of an emergency light control unit incorporating a LoRa and a BLE module. The overall dimension need not be any different to the usual dimensions of an emergency light of this type. This unit is intended to be used to provide the necessary emergency functions, when connected to a suitable light, for example an LED array.

[0053] The external casing 90 shows LEDs 91 , 92, 93 which are used to display the status of the emergency lighting system.

[0054] It will be appreciated that normal standards for secure and safe operation of the building LoRa need to be applied. The network has the potential to provide access to the building infrastructure, particularly as loT control becomes more widespread. Access control must be applied to limit those accessing the LoRa network to authorised users. Further, an appropriate level of encryption should be applied to messages travelling within the network. Integrity measure should be applied to prevent, for example, spoofing, modifying and re-play of messages.

Claims

1 . An emergency light, including a connection adapted for attachment to a building power supply, storage for electrical power which is adapted to be charged by the building power supply, a processor, and a wireless communication node, the wireless communications node being adapted to form a self-organising network with other nodes, and the network being accessible by other devices than the nodes.

2. An emergency light according to claim 1 , wherein the node is adapted to form part of a mesh network.

3. An emergency light according to claim 1 or claim 2, wherein the node is a LoRa device, and the network is a LoRa network.

4. An emergency light according to claim 3, wherein the light further includes a short range communication link, for example a BLE module.

5. An emergency light according to claim 4, wherein the link is a BLE module, and the light further includes a buffer to accept higher rate communications from the BLE connection, prior to transmission as lower rate communication on the LoRa network.

6. An emergency light according to claim 1 , wherein the light is adapted to receive commands via the node to initiate test processes and report a log of such test processes, via the wireless network.

7. A wireless communication network for a building, the network including a plurality of nodes associated with emergency lights according to any one of the preceding claims, the nodes forming a self-organising network within the building.

8. A wireless communications network within a building, including a plurality of self- organising wireless nodes associated with an emergency light, each emergency light being connected to the building power system and including a processor for controlling the wireless node.

9. A wireless communication network according to claim 8, wherein the nodes form a self-organised mesh network,

10. A wireless communication network according to claim 8 or claim 9, wherein each wireless node is a LoRa device, and the network is a LoRa network.

1 1 . A wireless communication network according to claim 10, wherein at least some of the lights further include a short range communication link, for example a BLE module.

12. A wireless communication network according to claim 1 1 , wherein the link is a BLE module, and the light further includes a buffer to accept higher rate communications from the BLE connection, prior to transmission as lower rate communication on the LoRa network.

13. A wireless communication network according to claim 8, wherein each light is adapted to receive commands via the node to initiate test processes and report a log of such test processes, via the wireless network.

14. A method of providing a wireless communication network within a building, wherein the network is formed including self-organising nodes associated with an emergency light as claimed in any one of claims 1 to 6.