GB2586966A - Communication system - Google Patents

Abstract

A radio communication system for installation in a facility consisting of at least one gateway unit 102 configured to transmit and receive messages according to a radio communication protocol. It further consists of a number of local units 104 each configured to monitor and/or control a respective local environment and to transmit messages according to the radio communication protocol. Each of the local units is configured to execute a route scan by transmitting a broadcast scan message, detect responses from in-range local or gateway units and determine a route for subsequent transmission from the local unit to the at least one gateway based on the number of hops.

Description

Communication System

Technical_ Background

The present disclosure relates to a communication system for allowing communications between local units and a central control centre.

Rackground A central control system can be implemented in a facility to allow for central control of heating, ventilation, and air conditioning (HVAC) assets. Such a central control system can be used to ensure that required comfort conditions of occupants of the facility are not compromised while reducing energy consumption of the assets and extending the assets' life span. Such a central control system can communicate with the HVAC assets via a wired connection or over a wireless network, with each asset communicating directly to a gateway or communication hub, which is responsible for communication with the central control system.

Summary

The inventors of the present invention have identified the problem of transmitting communication signals between local units and a central gateway unit within a large facility. Within such facilities, there may be a large distance between the local units and the gateway such that the signals are unable to reach the gateway directly due to signal attenuation. The inventors have devised the system and method disclosed herein to allow for communications in such an environment.

According to one aspect of the present invention there is provided a radio communication system for installation in a facility, the system comprising: at least one gateway unit configured to transmit and receive messages according to a radio communication protocol; a plurality of local units each configured to monitor and/or control a respective local environment within the facility and to transmit and receive messages according to the radio communication protocol, each local unit configured to: execute a route scan by transmitting a broadcast scan message; detect responses from at least some in-range local or gateway units, each response identifying the responding local or gateway unit and the number of hops of each responding local unit from the gateway unit; and determine a route for subsequent transmission from the local unit to the at least one gateway based on the number of hops.

Signal strength may also be conveyed in the responses and taken into account. In some embodiments this could be in addition to or as an alternative to the number of hops.

Each local unit may be configured to periodically transmit a data message over the determined route and await a gateway acknowledgement message.

Each local unit may be configured to use the determined mute is used until a configurable number of failed transmissions have been attempted.

The messages may be encrypted end-to-end.

The data message may include a header identifying the gateway and any intervening local devices to define the route.

Each local unit may be configured to transmit data messages in respective designated titneslots common to a group of local units and to select randomly a transmission time within the designated t flies' ot.

The random transmission time may be selected by dividing the tirneslot into a numbered sequence of sub-slots and randomly selecting a number to thereby select one of the sub-slots.

The at least one local unit is mounted on a control board of one or more temperature control device or environmental controller.

The temperature control device or environmental controller may be a panel heater or an air conditioning unit or any similar device.

The local unit may be mounted on an environment sensor.

The gateway may be configured to issue control command messages for reception at at least some of the local units.

The local units may be configured to respond to the control command messages to control the local environment.

At least one of the local units may be configured to transmit to the gateway a detected occupancy status of a room in which the said local unit is located.

The gateway may be configured to issue a control command message based on the detected occupancy status.

The detected occupancy status may be set for a period of time following the detection.

The control command message may comprise a determined set point from a plurality of predefined set points, the determined set point determined by a vacancy status of the room.

The vacancy status may be determined based on a facility booking system.

The pre-defined set points may comprise a minimum set point for cooling and/or a maximum set point for heating.

The local sensor unit and the local control unit may be paired via encryption, wherein the control unit is configured to transmit messages to the gateway.

Another aspect of the invention provides a local unit for communicating with a gateway within a radio communication system for installation in a facility having multiple local units, the local unit configured to monitor and/or control a respective local environment within the facility and to transmit and receive messages according to a radio communication protocol, the local unit configured to: execute a route scan by transmitting a broadcast scan message using radio modulation; detect responses from at least some in-range local or gateway units, each response identifying the responding local or gateway unit and the number of hops of each responding local unit from the gateway unit; and determine a route for subsequent transmission from the local unit to the at least one gateway based on the number of hops.

A further aspect of the present invention provides a system for controlling an environment, the system comprising: an electronic booking system of a facility for storing a vacancy status associated with a room of the facility; a central controller configured to receive from the electronic booking system the vacancy status of the morn and select an environment set-point front a plurality of environment set-points based, at least in part, on the received vacancy status, the environment set-points defining a desired current room environment state; an environment controller located in the room for controlling a current environment state comprising a lust local unit, the first local unit configured to receive from the central controller the selected environment set-point; and an environment sensor comprising a second local unit located in the room, the environment sensor configured to determine the current environment state and the second local unit configured to transmit the current environment state to the first local unit of the environment controller; wherein the environment controller is configured to determine and implement an environment controller setting based on the received selected environment set-point and the transmitted current environment state.

The current environment state may be the temperature of the room, wherein the environment set-points define different temperatures.

The environment controller setting may be a temperature at which the environment controller is to be set.

The system may comprise a plurality of environment controllers, each environment controller located in a different room of the facility and each comprising a first local unit.

in one arrangement, the first local unit receives the selected environment set-point from the central controller via a gateway unit, and the gateway unit configured to transmit and receive messages according to a radio communication protocol.

The first and second local units may be configured to transmit and receive messages according to a radio communication protocol.

A further aspect of the invention provides a central controller for controlling a current environment state of a room in a facility, the central controller configured to: receive from an electronic booking system a vacancy status associated with the room; select, based at least in part on the received vacancy status, an environment set-point from a plurality of environment set-points the environment set-points defining a desired current room environment state; and transmit to a local unit of an environment controller located in the room the selected environment set-point, the environment controller for controlling the current environment state and configured to determine and implement an environment controller setting based, at least in part, on the received selected environment set-point.

Brief Description of the Drawings

To assist understanding of the present disclosure and to show how embodiments may be put into effect, reference is made, by way of example only, to the accompanying drawing in which Figure 1 shows an example mesh network; Figure 2 shows an example process for establishing and maintaining a connection between a local unit and a gateway; Figure 3 shows a timeline for establishing a connection; Figure 4 shows an example user interface for viewing results for multiple facilities; Figure 5 shows an example user interface for viewing results for a single facility; Figure 6 shows an example ast,r interface for viewine, results for a single room; and Figure 7 is an example process for establishing a connection between the local unit and the gateway.

Detailed Description

The present disclosure relates to a communication system which allows local units to communicate with a gateway unit, which, in turn, communicates with a central control centre. The central control centre controls the local units via this communication network. Local units may monitor a respective local environment within a facility, and transmit signals to the central control centre via the gateway unit. Response signals ate transmitted back to the local units, which may control a respective local environment.

The present disclosure uses the example of a central heating control system within a hotel. Panel heaters or other heating control related units comprise local units, as set out below, and the hotel is the facility. However, it will be appreciated that heating control is just one example of the possible implementations of the disclosed communication system.

Communication Network The central heating control system described below requires a communication network so that the panel heaters can communicate with the central heating control centre. In the disclosed communication system, long range (LoRa) radio communication is used, although it will be appreciated that any other suitable protocol may be used. Any radio modulation could be used in the present system to transmit data.

Figure 1 shows an example network used to communicate between the panel heaters 104 and the central heating control centre 120. A similar system may be used to control other appliances. For example, the panel heaters 104 may be replaced by air conditioning units. The principals of the communication network are independent of the appliances being controlled such that the routing software does not need to be altered for use with different appliances.

Figure I shows five panel heaters 104a, 104b, 104e, 104d, 104e, which comprise local units. Each local unit has a unique local unit H) or address associated with it. Each of the panel heaters are situated in a respective different room of the hotel. As discussed above, this may not always be the case. The central heating control centre 120 may be located remotely, accessible via a network 100 such as the intermit. The panel heaters 104 communicate with the central heating control centre 120 via a gateway unit 102, which is likely to he on site. It will be appreciated that there may be one Or more gateways 102 via which the panel heaters 104 can communicate with the central heating control centre 120. The gateway unit is configured to transmit and receive messages according to the radio communication protocol.

In order for the panel heaters 104 to be able to communicate with the gateway 102, they each receive a 'smart card' in the form of a board carrying a chip, wherein the chip is the local unit. The smart board can fit into an existing slot at the rear of certain panel heaters. The chip enables radio communication between the panel heater, which acts as a node in the communication network, and all other nodes and the gateway in the network. Each node can send and receive messages over the mesh network.

The gateway 102 acts as a central router in the network within the hotel. That is, all messages which are sent to or from the central heating control centre 120 are received by the gateway 102 before being sent on to their respective end location.

The gateway 102 may be positioned anywhere in the hotel. Buildings in which the disclosed communication system is likely to be used are often very large and may have thick walls which result in increased attenuation of radio signals. As such, in certain buildings a problem arises in that it is unlikely that every panel heater 104 will be able to communicate directly with the gateway 102.

A mesh network 130 has been devised which allows panel heaters 104 which cannot communicate directly with the gateway 102 to he able to communicate with the gateway 102 indirectly.

The mesh network 130 may be used to transmit current information about the room to the central heating control centre 120. Such information may include the current temperature of the room and/or the occupancy of the room, as described below, This information may be gathered and monitored by sensors, comprising local units, positioned in the room. The central heating control centre 120 may transmit set points to the panel heaters 104. Set points are described in more detail below, but they are used to define the desired room temperature to be achieved by the panel heaters 104 based on the current state of the room.

Figure 2 shows an example process for establishing a connection between the panel heater 104c and the gateway 102. When the panel heater 104c is turned on, the local unit within the panel heater 104c sends out a route scan message at step 5201. This is received by the local units of all of the panel heaters 104 which are in-range of panel heater 104c and by the gateway 102 if it is in-range.

The local units of the panel heaters 104 act as nodes in the mesh network 130 which are trying to connect to the gateway 102. Paths may be formed between the nodes for indirect communication between a given node and the gateway 102. It will be appreciated that other appliances may additionally comprise local units and thus be used as nodes, for example, the environment sensors. electrical appliance control units, or boilers. For a local unit to be able to receive a signal, the appliance it is located in must be on. That is, the smart card in the panel heater, for example, must be receiving power; the panel heater need not be heating. Any local unit which is not receiving power, for example any local unit in a panel heater which is turned off, cannot act as a node in the mesh network 130. One advantage of the route finding technique described herein is that it inherently only finds routes with 'active' nodes.

The panel heater 104c receives route scan responses from the nodes which received its route scan message, step S202. These messages define the paths by which the panel heater 104c can communicate with the gateway 102. Each message comprises the number of 'hops' in the path, the signal strength of each hop, and the nodes along the path. A hop is defined as a connection between two nodes in the mesh network 130.

Figure 1 shows four example paths between the panel heater 104c and the gateway 102. Path 106 is a direct path between the panel heater 104e and the gateway 102. There may not always be a direct path between a given panel heater and the gateway 102 as discussed above. A 1-hop path, comprising connections 108a and 108b is shown, in which messages are passed via panel heater 104e. Two 2-hop paths are shown. The first comprises connections 110a, 1.10b, and 110c, via panel heaters 104b and 104a. in the example of Figure 1, panel heater 104a has either not received the route scan message from panel heater 1.04c or its route scan response was not received by panel heater 104c, as indicated by the lack of a direct connection between the two panel heaters 104a, 104c. A second 2-hop path is shown comprising paths 112a, 112b, and '108b, via panel heaters 104d and 1.04e For the example paths shown in Figure 1, the panel heater 104c would receive four route scan response messages. These messages are from the gateway 102, panel heater 104b, panel heater 104d and panel heater 104e.

At step S203, the panel heater 104e prioritises the possible paths defined in the route scan responses. The panel heater 104c considers both the number of hops required in the path and the signal strength of each hop when prioritising the paths. That is, a path with more hops may be preferred over a path with fewer hops if the signal strength along each path hop in the path is higher.

Consider the following example, not shown, in which Device D is route scanning to a network consisting of the following paths: Device A connected directly to Gateway; Device B connected directly to Gateway; and Device C connected to Device B. It is further argued that Device D can only "see'' Device A and Device C. Device D has the following information when making its decision on which route to use: o Device A * Has 0 hops to the gateway.

* Signal strength from Device A to Gateway * Signal strength from Gateway to Device A * Signal strength from itself (Device D) to Device A * Signal strength from Device A to itself (Device D) o Device C * Has 1 hop to the gateway (through Device B) * Signal strength from Device C to Device B * Signal strength from Device B to Device C * Signal strength from itself (Device D) to Device C * Signal strength from Device C to itself (Device D) * It will not know the signal strengths between Device B and the Gateway Reverting to Figure i, the panel heater 104c connects to the gateway 102 using a chosen route, step S204. Determining which path to use as the chosen route to connect to the gateway is discussed below with respect to Figure 7.

During use, the panel heater 104c both transmits messages to and receives messages from the central heating control centre 120 via the chosen path.

The panel heater 104c transmits a report at step S205. The periodicity at which the panel heater 104c transmits reports is predefined. For example, the panel heater 104c may transmit a report to the central control centre 120, via the gateway 102, every 15 minutes. Other devices may send reports at other time intervals. For example, sensors may send reports every 5 minutes. The periodicity of report transmission may be referred to as a report time. The local unit has to transmit a report once in every report time window. At connection set-up, the time at which the panel heater 104c transmits its report relative to the beginning of the report time window is determined, as discussed later. Each node in the mesh network 130 has its own transmission time.

The panel heater 104c checks that it is receiving signals from the control centre 120 at step S206. The panel heater 104e may, for example, receive acknowledgement messages from the control centre 120 after the control centre 120 receives the signal from the panel heater 104c. If the panel heater 104c is receiving signals, or has received a signal within a given time period, the process moves to step S206, where the panel heater 104c waits until a next transmission time, which occurs in the next report time window, when a next signal is transmitted, S205.

This cheek performed at step S206 may occur at a pre-defined time after the panel heater 104c transmits the signal, for example after a time interval which is equal to the time expected for the report transmitted by the panel heater 104c to reach the control centre 120 and then a response signal to be transmitted from the control centre 120 to the pane! heater 104c. The panel heater 104c may check for receipt of such a signal for a time period which encompasses the expected receival time. For example, the panel heater 104c may check for a signal received from the control centre 120 for a time interval of 30 seconds, commencing 15 seconds before the expected receival time and ending 15 seconds after the expected receival time. Alternatively, the panel heater 104c may continuously check for a predefined time period from transmittal of its signal at step S205, the predefined time period encompassing the expected receival time.

however, it is found at step S206 that signals are not being received, there is a problem at some point along the chosen path which prevents communication between the panel heater 104c and the central heating control centre 120.

In some embodiments, if it is found at step S205 that there has been no signal received at the panel heater 104e at the expected time, the panel heater 104c will continue to use the current chosen path to transmit reports to the control centre 120.

There may be a pre-defined number of times the panel heater 104c may continue to transmit reports to the control centre 120 using the same path while not receiving an acknowledgement signal at step S205. For example, the panel heater 104c may allow for three consecutive transmitted reports to be unacknowledged by the control centre 120. It will be appreciated that the pre-defined number of allowable failed report transmissions may he zero, or it may be any integer greater than zero. 1 0

At step S208, the panel heater 104c determines if it may attempt another report transmission. If it can, the process proceeds to step S209, where the panel heater 104c waits a time period At, before sending another report to the central heating control centre 120 via the gateway 102 using the current route, step S205.

The time period At of step S209 may be determined by the report time and the pm-defined number of allowable failed report transmission. For example, if the panel heater 104c transmits reports every 15 minutes, and 15 attempts are allowed, At may be 60 seconds. It will be appreciated that the re-transmissions may not he equally spaced over the report time. For example, all attempts may be performed with the first quarter of the report time.

In some embodiments, the transmitted signals do not need to be received by the gateway 102 and central heating control centre 120 before the beginning of the next report time window. That is, the total of all time periods At for the allowable attempts of a single signal may be greater than the report time, and/or they may extend into the next report time window.

When a data packet is generated by the local unit of the panel heater I04c for transmission, it is added to a buffer of the local unit. Report packets may be queued in the buffer, such that the most recently generated data packet is added to the back of the queue. When the panel heater 104c attempts a transmission, it attempts to transmit the data packet at the front of the queue in the buffer.

After the predefined number of allowable failure transmissions has been reached, the panel heater I04c disconnects from the mesh network 130, step S210. It may then attempt to reconnect, starting the process again at step S201.

Alternatively, in order to maintain a connection; the panel heater may connect to the gateway using the next highest pi iority path found in step S203 at step S207. The panel heater 104c checks that signals are being received at step S206. This may not be preferable over disconnecting and re-finding the available paths as found initially because the dynamics of the mesh network 130, that is, the paths within the mesh network 130, are likely to have changed.

The panel heater 104c continues to check that signals are being received, 5206, from the central heating control centre 120 in response to transmitted reports for the entire duration for which it is switched on. The chosen route will continue to be used by the panel heater 104 to communicate with the gateway 120 until the predefined number of acknowledgements have not been received. *11

The transmission time is a predefined time, defined upon connection to the gateway. It is not dependent on the time at which a successful report is transmitted from the panel heater 104e. For example, if the panel heater 104c has a report time of 15 minutes, and the transmission time is 3 seconds into the report time window, for the 12:00 report time window, the first attempt report transmission will occur at 12:00:03. A successful transmission may only occur at, for example, 12:07:03, after one or more failed transmission attempts. However, the first attempt of the next report to be transmitted will still occur at 12:15:03, 3 seconds into the next report time window, even though this is less than 15 minutes after the last successful transmission. It will be appreciated that the times provided here are included by way of example only.

Figure 7 shows a more detailed flow diagram of an example process used by a node of the mesh network 130 to connect to the gateway 102.

The process starts at step S700. The local unit may be turned on at this step, or the local unit may have become disconnected from the gateway 102 and is attempting to reconnect.

At step S702, the local unit sends out a route scan request, from a broadcast address, which is searching only for the gateway 102. That is, the local unit sends out a request to connect directly to the gateway 102. That is, the local unit is searching for devices with a 0-hop route.

The local unit waits a predetermined time period to determine if a route scan response is received on the broadcast address, step S704. In the example process of Figure 7, the predetermined time period is between 10 and 15 seconds.

At step S706, the local unit orders the options received in the responses from the best option to the worst option. In some embodiments, there is only one gateway 102 in the mesh network 130, or only one in-range gateway 102. In such an embodiment, there is only one entry in the list. However, there may be more than one in-range gateway 102. Only the best 16 route options are kept.

If at least one route scan response was received at the local unit, the local unit takes each route in turn, from best to worst, step S708, and performs the following steps until either the local unit is connected to the gateway 102 or all of the routes in the list have been tried.

The process proceeds to step S710, where the local unit sends a join request through the best route on the broadcast address. That is, it sends a join request directly to the gateway 102 corresponding to the best route.

The local unit calculates a timeout, step S7 12. The timeout is the time period which is expected between sending a signal to the gateway 102 and receiving a response signal. The timeout is calculated as a random time between 5 and 7.5 seconds multiplied by the number one greater than the number of hops in the route. Since the route between the local unit and the gateway 102 is direct, there are no hops in the route.

The local unit waits for up to the calculated timeout for a matching join response to be received, step S714. The matching join response is a message sent from the gateway 102 hi response to receiving the join request. If a join response is received. the local unit is connected to the gateway 102 directly. If no join response is received. The local unit is not connected to the gateway 102.

At step S716, the local unit determines if a valid join response was received. If it was, the local unit is connected to the gateway 102, step S736.

However, if no join response is received, the local unit proceeds to try to connect to the gateway 102 via the next best route, 5708. The steps S710-S716 are repeated for the next best route. It will be appreciated that each alternative route found will connect the local unit to a different gateway.

If the local unit does not receive a valid join response, and there are no more direct routes to attempt to connect to the gateway 102, the local unit attempts to connect to the getaway 102 via a mesh route, that is, it tries to connect via other local units in the mesh network 130.

Ln some cases, the local unit may receive no route options at step S706. This may be because there are no gateways 102 in-range of the local unit. In this case, the processes proceeds directly to step S718.

At step S718, the local unit sends out a route scan request from a broadcast address. The route scan is searching for any mesh device which is connected to the gateway 102 or the gateway 102 itself. The local unit may define a maximum number of hops away from the gateway 102 which is acceptable. For example, it may request that only local units which are within 8 hops of the gateway 102 respond to the route scan. The local unit waits for between 20 and 30 seconds for route scan responses to be received on the broadcast address, step S720.

At step S722, all of the routes for which route scan responses were received are ordered from best to worst. The ranking of a route may depend on the number of hops in the route. It may also depend on the quality of the connections of each hop of the route. Only the best 16 routes are kept. It will he appreciated that there may be fewer than 16 routes found, in which case all routes are kept.

The local unit takes each route in turn, from best to worst, step S724, and performs the following steps until either the local unit is connected to the gateway 102 or all of the kept routes have been tried.

At step S726, the local unit sends a join request through the route through which connection is being attempted on the broadcast address. That is, in the first iteration, the local unit sends the join request via the best route as found in step S722, in the second iteration via the second best route as found in step S722, and so on.

At step S728, the timeout for the route being tested is calculated. This is done in the same way as at step S710, but with the relevant number of hops in the route. The local unit waits for up to the timeout for a matching join response to be received. step 5730.

The local unit may not have to wait the full timeout response. If a matching join response is received at the local unit prior to the end of the timeout period, the local unit can proceed to the next step in the process without having to wait for the period to finish. This is true of step S714 as well.

The local unit determines if a valid join response was received for the route being tested at step S732. If a valid join response was received. the local unit is connected to the gateway 102 via said route, step 5736. The remaining routes need not be tested.

However, if no valid join response is received at the local unit, the process returns to step S724, where the next best route option is selected and used to attempt connection to the gateway 102.

If the local unit returns to step S724 without connecting to the gateway 102 having tried connecting via all of the kept routes, the local unit disconnects, step S734 In some cases, no routes to the gateway 102 are found at step S720. In such a scenario, the local unit is disconnected, step S734.

After disconnecting, the local unit may attempt to connect to the gateway 102 again, starting at step S700.

In some embodiments, the mesh network 130 comprises one or more repeaters. Repeaters are local units which do not perform another function, that is they are not situated within a panel heater or sensor, for example, but act only as nodes in the mesh network 130. In such an embodiment, it may be preferable for the local units to connect to the gateway 102 via a repeater rather than via another type of local unit, particularly where local units may unpredictably be turned off. The type of local unit may be identified in the local unit ID or address. This may provide some robustness to the mesh network 130.

For example, an occupant of a room may turn off the panel heater 104 in the room. This removes the local unit associated with the panel heater 104 from the mesh network 130. That is, the local unit of said panel heater 104 cannot act as a node in the network 130, so no routes to the gateway 102 can be used which pass through said panel heater 104. Any other node in the network 130 which was using the turned off panel heater 104 in its connection route would be required to reconnect, by sending out a route scan. If too many local units try to reconnect at the same time, the network 130 may become congested.

By introducing repeaters into the network 130, the network is less susceptible to alterations by occupants so increasing robustness. Defining a primary connection route to be via a repeater may further increase the robustness of the mesh network 130.

In such an embodiment, the process of Figure 7 may be modified in the following way. Prior to step S718, where route scans are sent to search for any mesh device, there is a step of searching for a repeater. If a repeater is found to be in-range, the local unit sends a join request to the gateway 102 via the repeater, calculates the Unicorn, waits for up to the timeout, and then determines if a valid join response was received. These steps are the same are steps S710-S716 and S726-S732 of Figure 7. As above, if multiple repeaters are found, the routes associated with each may be ordered and the best 16 tested.

If a valid join response is received, the local unit connects to the gateway 102 via the repeater of that route If after attempting to connect via all found repeaters, however, no join response is received, the process proceeds to step S718, where the local unit sends a route scan searching for other types of mesh devices. A connection route via another type of local unit is a secondary route.

In some embodiments, a connection route between a local unit and the gateway 102 may include both repeaters and other types of local units. For example, a first panel heater may be connected to the gateway 102 via a repeater. A second panel heater may transmit signals to the gateway 102 via the first panel heater, such that the route between the second panel heater and the gateway 102 compises the first panel heater and the repeater.

IS

In some embodiments, a local unit may send signals to a repeater which may, in turn, transmit to another type of local unit. For example, a panel heater transmits to a repeater which transmits to another panel heater which is in direct communication with the gateway.

It will be appreciated that the example of searching for routes comprising up to 8 hops at step 57I8 is an example only. .Any number of hops may be defined. In some embodiments, the local unit may define a lower number of hops, for example 2. Steps 5718-5732 of the process are performed for the routes comprising 2 or fewer hops. If no connection is made via one of these routes, the process may return to step S718, where a higher number of hops, such as 4, is defined. The steps may be performed for this group of options. Incremental testing of route options comprising different hop numbers may continue in this way until a maximum number of allowable hops in a route is reached, at which point the local unit will disconnect if none of the routes are valid.

In some embodiments, the local unit may only receive route scan responses from other local units which are on paths with a number of hops less than or equal to the maximum defined in steps 5702 and S718. The local unit may define the number of allowable hops in the route scan message which is broadcast, such that only those on paths meeting the criterion respond. In other embodiments, all in-range nodes of the mesh network 130 respond to the route scan, and the local unit determines which of these meets the hop number criterion.

The local unit may determine the number of hops in a route from the route scan response. The route scan response comprises the pathway used by the transmitting local unit (the local unit transmitting the route scan response) to connect to the gateway 102. For example, if the transmitting local unit is on a 1-hop path, the pathway will include the address of the transmitting local unit, and the local unit through with the transmitting local unit connects to the gateway 102. Taking route 110 of Figure 1 as an example, the route scan response sent by panel heater 104b would comprise the addresses of panel heater 104b and panel heater 104a, since it is a 1-hop path front panel heater I04b to the gateway 102. The pathway sent in the route scan response, therefore, identifies which, local units are used in the route of the transmitting local unit to connect to the gateway 102.

It will be appreciated that the steps of the example process of Figure 7 may be altered. Some steps may not present in the process. For example, the local unit may not search for a direct connection to the gateway 102 initially. It may start at step 5718, such that all possible routes are found, and then connection via the best option attempted first.

There may be additional steps included in the process of Figure 7, such as those discussed above with reference to connecting to a repeater in preference to another type of local unit.

Some of the steps may be performed in a different order or simultaneously. For example, the steps of calculating the timeout, steps 5712 and S728, may be performed prior to sending the join request, steps S710 and S726, or these steps may be performed simultaneously.

Some steps may be altered. For example, the time period which the local unit waits for a route scan response to be received may be different. The time periods may depend on the physical structure of the network, and/or the number of allowable hops. For example, if the nodes of the network are positioned further away from each other, the time periods may be higher.

It will he appreciated that the kepi ordered lists of routes which the local unit attempts to connect to the gateway via many be any length. 16 routes is used here as an example.

In some embodiments, there may be local units which do not functions as nodes of the network 130. These local units may consume the network, that is they transmit signals via the network, but they may not receive signals from the network, so cannot relay data packets to other local units. An example of a device in which such a local unit may be positioned is a battery powered sensor. Since it is not connected to the mains, it conserves power by only turning on to affect its function, e.g. measuring room temperature, and send its report packets. The device then switches off again.

In some embodiments, it may be possible to define which local units act as nodes in the network 130. Local units which can act as nodes may respond to route scan messages, whereas those which cannot act as nodes may not respond to route scan messages. Whether the local unit is defined as a node may depend on a number of factors. The user of the system may be able to classify the local units as nodes or non-nodes. The user may, for example, define any local unit which is positioned in a device which could be turned off, for example by a room occupant, as a non-node. The configuration of the mesh may also determine which local units are defined as nodes and which are not.

It will be noted that the panel heater 10:1c chooses a path to connect to the gateway 102 on, rather than choosing a first node from which to receive data packets sent from the panel heater 104c. This has the effect that, once a node is involved in a path, the path cannot be altered. For example, the panel heater 104c chooses to connect to the gateway 102 along the 3-hop path 110. At some point during the use of panel heater 104c, panel heater 104a is turned off This results in signals no longer being received by panel heater 104e. The path of communication cannot be altered, for example, by panel heater 104b connecting directly with the gateway 102. This would be a different path. As such, the panel heater 104c tries to connect with the next most preferential path.

The path for routing a message is defined in the header of the message sent to or from the panel heater. The transmitting node broadcasts a message, such that the packets of data are sent to and received by all nodes of the network which are within reach of the transmitting node. However, only the next node in the path, as defined in the header, will broadcast the received message. The data packets are passed along the chosen path in this way.

The data packets sent in the mesh network 130 may be encrypted. The headers may be read by any node in the mesh network 130, so that the data packets may be transmitted along the chosen path, but all other parts of the message are encrypted, such that intercepted signals cannot be read. Keys are applied end-to-end, such that only the node from which the message originated and the control centre 120 are able to read the message.

In embodiments in which sensors and panel heaters are paired, the sensors may also have access to the session key such that the data sent from the senor to the panel heater is encrypted but also readable by the panel heater. Alternatively, the data transmitted from the sensor to the panel heater may not be encrypted. The data may then be encrypted by the panel heater before being transmitted to the central heating control centre via the path in the mesh network.

The inventors have chosen to use Advanced Encryption Standard (AES) 128, but other encryption standards may alternatively be used Any symmetric key cipher may be used for encrypting the messages. In the chosen method, the session keys are shared on connection of the network. From this point, the same keys are used. To prevent an unauthorised user from sending-counterfeit messages, the messages are changed each time another message is sent. For example, there may be a counting field in the message which comprises a number, the number increasing by 1 each time a new message is transmitted. This means that an unauthorised user cannot reproduce an identical copy of a message for use.

Since all nodes in the mesh network broadcast the messages they transmit, such that all nodes within range receive the messages, there. must be some control over the timing of broadcasting messages from each node to prevent collision of signals. The collision of two or more signals results in interference of the signals, so the data packets are no longer viable. If signals collide, the transmitting node must attempt to retransmit the signal.

As described above, the transmitting panel heater 104c receives an acknowledgement message from the control centre 120 in response to the transmitted signal. If the panel heater 104c does not receive any such acknowledgement signal within an expected time period, then one of the signal transmitted by the panel heater 104c and the acknowledgement signal has collided with another signal in the mesh network 130. If such a collision occurs, such that the panel heater 104c does not receive the acknowledgement message, the panel heater 104c may retry transmitting to the control centre 120 via the same path, as described above. There may be a pm-defined number of times the panel heater 104c tries to transmit to the control centre 120 via the same path before attempting to use a different path. For example, the panel heater 104c may attempt to use the same path 15 times before attempting to connect via a different path. If the panel heater 104c is unable to connect in the pm-defined number of attempts, it may disconnect from the mesh network 130 and then perform a route scan again to attempt to reconnect.

The inventors have identified that there must be a balance between sending messages frequently enough for the required control signals to be received and implemented in a reasonable thneframe and sending the messages infrequently enough that the traffic density of the network is not so high that signal transmission needs to be retried too frequently, i.e. ensuring the network 130 is not congested.

This is a particular problem when all of the nodes of the mesh network are turned on at the same time. This may occur, for example, at set-up or after a power-cut.

Figure 3 shows an example timeline for the entire network being turned on at the same time. The nodes are turned on at time t1. The aim is for all of the nodes to be connected to the gateway 102 before the end of the set-up period, as defined by t4. The inventors have achieved this using the following method.

The time difference between tl and t4 may, for example, be 30 minutes. In some embodiments, the set-up period corresponds to the report period of the local units. There is a predefined first attempt time window Ati in which each node attempts to connect to the gateway 102. The predefined first attempt time window al may, for example, be 7 minutes 30 seconds. This is split into 450000 milliseconds, where each millisecond after t1 is assigned a unique number between 1 and 450000. When the mesh is turned on, each node determines a random number between 0 and 450000. This then defines the time offset in milliseconds at which that node first attempts to broadcast its route scan.

The random number is generated through a source. of natural entropy on the board.

When a node attempts to connect during the first attempt time window Ati, there are two possible outcomes. The first is that the transmission is received, either directly or indirectly, by the gateway 102, and an acknowledgement signal received at the node, such that a connection is established between the node and the gateway 102. If this is the case, the node need not attempt to transmit any further messages during the set-up period. The time at which the node transmitted the signal, as defined by the random number, is then the transmission time of that node.

If. however, the first attempt message is not received at the gateway 102 or a response message sent from the central heating control centre 120 is not received at the node, no connection is made between the node and the gateway 102 during the first attempt time window int. There is defined a second attempt time window Ar2 in which any nodes which did not connect to the gateway 102 during the first attempt time window reattempt to connect. The time period At2 is divided into milliseconds and the unconnected nodes generate a random number with a maximum allowable value as the number of milliseconds in the time period, as was done in the first attempt dine period. The nodes then reattempt to connect with the gateway 102 at their time offset defined by the randomly generated number.

It will be appreciated that zlt2 may be the same as At1, or the two values may be different. For example, At2 may be smaller than At1 since it is assumed that at least one of the nodes in the mesh network will have connected to the gateway 102 during the first attempt time window At1. To avoid any nodes retrying to connect to the gateway 102 before all nodes have attempted to connect for a first time, the first and second attempt time periods do not overlap. There may bc a time gap between the end of MI and the start of At2 to help avoid any collision of messages.

There may be further attempt time windows within the start-up period t1 to t4. This is to ensure that all nodes are routed to the gateway 102 by the end of the period t4.

Each attempt time window it1, dt2 may be subdivided into any increment and the number of increments used to define the possible random number each node may be assigned.

The transmission time for any given node in the network 130 is the total time offset from the beginning of the set-up period t_(1) at which the node transmitted the signal which successfully connected. For example, if the signal which resulted in a connection to the gateway 102 was transmitted 35 seconds into the third attempt time window, with the first attempt time window being 7 minutes and 30 seconds in length, and the second attempt time window being 5 minutes in length, the transmission time of the node in question is 13 minutes 5 seconds.

The total time period required for a signal to be transmitted from a panel heater 104 to the central heating control centre 120 and for a feedback signal to be sent from the control centre to the panel heater 104 may be about -4s. Therefore, even if no two nodes generate the same random number in an attempt time window, i.e. no two nodes transmit at the same time, there may still be some collision of signals.

It will be appreciated that, in most instances, not all local units will he trying to connect to the gateway 102 at the same time. In many instances, the nodes will establish a connection to the gateway 102 when installed. Installation of nodes in the network would likely not be simultaneous, so preventing the network from becoming congested. The nodes would remain connected to the gateway 102 via the same route unless they lose power.

The probability of the transmitted signal successfully connecting the node to the gateway 102 is based, at least in part, on the number of hops. There is a probability [of collision?]. xn, associated with each hop, such that each hop is associated with a probability of non-collision, 1. -xn. The probability of a transmitted signal successfully connecting the node to the gateway is, therefore, the multiple of each hop in the path the signal takes from being transmitted by the node to the response signal returning to the node. That is, for a path with N hops, the probability of non-collision, and so connection, is: p(connection) = (,(1 -x1)(1. -x2) .. (1 -Although this may appear to favour paths with fewer hops, such paths may have a higher probability of collision associated with each hop.

However, there are a number of reasons the probability of connection as defined above is not trivial to calculate. The value of x_n is not constant. It is dependent on, for example, the other signals in the network, such that the value of x_ti changes when new nodes are introduced into the network 130. It may also be different for each direction of travel, i.e. it differs when being used to transmit to the gateway 102 and from the gateway 102. It may also depend on the time of transmission from the node since there may not be a common report time for all nodes in the network and different nodes transmit at different times.

To overcome these difficulties, the inventors of the present invention have used a Monte Carlo simulation to tune the parameters of the network 130. The Monte Carlo simulation allows for a large number of different values of the parameters to be tested in order to find the optimum combination.

The parameters which have been tuned using the Monte Carlo simulation are: * the number of allowable failed transmission before disconnection from the network occurs; * the time delay before a subsequent transmission is attempted after a failed transmission, At of Figure 2; and * the time window over which the retries may be attempted.

It will be appreciated that other parameters may also be tuned using the Monte Carlo simulation. For example, the simulation may be used to determine other time periods, such as the attempt windows of Figure 3. It may also be used to determine the maximum number of local units the network 130 can support, and/or the number of gateways 102 required in the network 130.

Heating Control The heating in a facility comprising a plurality of heaters, for example panel heaters, can be controlled by a central heating control centre managed at a local on-site gateway. The gateway may be self-standing, or may depend on software executed on the Cloud. Signals can be transmitted from the central heating control system to the panel heaters, and vice versa, via the communication system described above.

In the present disclosure, a hotel is used as an example of the facility. It will be appreciated that the heating control system may be used in any facility in which multiple heaters are controlled, such as student accommodation blocks, care homes, secure residential housing, hospitals, offices, etc. There may be one or more heaters in each room of the facility. The heater in each room of the facility can be controlled independently, or multiple heaters can be controlled together.

A central heating control system comprises the central heating control centre and one or more panel heaters. each comprising a local unit. The central heating control centre controls the panel heaters in the facility. The system may comprise other components, such as environment sensors, as discussed later, which may also comprise local units.

The central heating control centre may be integrated with the hotel booking system. Each room may be in either a booked or vacant state. If the room has not been booked, then the room is in a vacant state For the duration of the time for which the room is booked by a guest, the room is in a hooked state. That is, the room has a scheduled occupancy. In embodiments when the system is used in facilities other than hotels, the room may still be vacant or booked, such that a room is booked if there is a person designated to the room.

The state of the room may be checked and changed at a set one or more times each day. For example, the state of the room may be checked at the latest chock-out time defined by the hotel, and again at the earliest cheek-in time. The state of the room will change from booked to vacant at the latest check-out time if an occupant of the room is leaving the hotel. It will remain in the vacant state at the earliest cheek-in time if the room has not been booked for that night. If the room has been booked for that night, the state will change from vacant to booked at the earliest check-in time.

In some embodiments, the room state is only checked once a day. The room may he determined to remain booked if it is booked on two consecutive nights, even if the guest for each night is different, i.e. one guest checks out and another cheeks in.

In other embodiments, the state of the room may be changed when guests check in and out of the hotel. That is, the state of the room can be changed at any time, the time determined by the arrival and departure times of the guests.

The central heating control centre determines the state of the room from the booking system. The booking system comprises a database, which stores the booking information for each room in the hotel. The database may comprise a room ID, corresponding to the unique room number of the room, and a booked status which identifies whether a room is booked or not. The booked status of a room may be pulled by the central heating control centre at predetermined times throughout the day, or it may be pushed by the hooking system at predetermined times or when there is a status change.

In an alternative embodiment, the central heating control system may not be integrated with the booking system. Instead, the state of the room is input manually. The state may be input in advance, such that the central heating control centre stores the future scheduled occupancy of each room. Alternatively, the state may be input manually when the state of the room changes, i.e. when guests check in or out of the hotel.

Once the state of the room has been determined, one or more set points for the room are determined. A set point is a desired room tempetame, which the system aims to maintain the room at. For each state, two set points may be defined: one for when the room is occupied and one for when it is unoccupied. A room is defined as occupied if there is one or more persons present in the room -this may be different to a 'booked' state.

Additional set points may also be defined. For example, there may be a night-time set-point defined which is lower than the daytime set-point. There may be a predefined time at which the set-point changes from the daytime set-point to the night-time set-point and vice versa.

Set-points may be defined for different months or seasons. For example, the defined set-points may be lower in summer than in winter.

The set-points may be defined for different local weather conditions. In such an embodiment, the central heating control centre receives local weather data and uses said received weather data to determine which of the predefined set-points to implement. The local weather data may be determined using an external environment sensor, which may communicate with the central heating control centre in a similar manner as the panel heaters, as described later. Alternatively, the local weather data may be collected from a third-party source, such as the BBC or The Weather Channel.

In some embodiments, the occupancy of the room may not be used to determine the set-point. The set-point may still be determined by the state of the room, and any other external factors such as weather, season, etc., but there are no set-points defined which are based on occupancy.

The default set points are determined centrally. These may be input by a control user, for example, a member of the hotel management staff. The default set points may be the same for every bookable room in the hotel, or they may vary. Rooms may be grouped such that the set points for a group of rooms are controlled together.

The occupant of a room may be able to alter the set point of his room. He may manually change the temperature on the heating panel, or other heating control module, in his room. This change is then reported to the central heating control centre via a communication network as described later. The set point for the room is then changed at the central heating control centre. This occupant-adjusted set point remains as the set point for the room until the occupant checks out of the room, at which time the set points are reset to the default set points.

In some embodiments, a maximum and/or minimum set point may be defined. For example, a maximum set point temperature of 30'C may be defined. This restricts the maximum temperature to which the occupant can set the temperature of his room to 30°C. Alternatively, the maximum set point may allow the occupant to temporarily set the heating panel temperature to a higher temperature, for example for a predefined time, but after that time the temperature is reduced to the maximum set point. The maximum set-point may be month or season dependent.

In some embodiments, there may be one set point defined for rooms in a vacant state, and two set points (occupied and unoccupied) defined for a room in a booked state.

The occupancy of the room is determined. This may be achieved by occupancy sensors. Such sensors tiny, for example, detect movement within a room. Occupancy sensors may be located in each bookable room of the hotel. There may be one or more sensors in each room.

In some embodiments, the occupancy sensor communicates the occupancy of the room to the central heating control centre. The central heating control centre can then determine which of the set points should be applied to the room. This set point is then transmitted to the heating panel in the room, which can adjust its temperature accordingly.

The environment sensor may communicate the occupancy of the room to the central heating control centre directly, or this information may first be sent to the heating panel, which in win transmits the occupancy to the central heating control centre. This is determined by the message header.

In an alternative embodiment, the possible set points for the current state of the room may he sent to the heating panel. For example, if it is determined that the room is booked, both the occupied and unoccupied occupancy set points are transmitted to the heating panel. The environment sensor determines if the room is occupied and transmits this information to the heating panel. The heating panel uses this received information to determine which of the two set points to use.

In embodiments in which the environment sensors send data to the panel healers, the sensor acts as a child device to the panel heater, and that these two components are paired.

Environment sensors may be used to monitor the temperature of the room. Temperature sensors, for example, may be used. The sensed temperature of the mom is transmitted to the heating panel. This allows the heating panel to compare the room temperature with the set point determined using the room state and occupancy and determine, based on the comparison, whether to adjust its temperature settings and by how much.

The sensed room temperature may also be transmitted to the central heating control centre, either by the heating panel or directly by the environment sensor.

The data collected by the environment sensors may be continuously analysed for control purposes. As discussed above, this data may he sent to the panel heaters or to the central heating control centre, or both.

In some embodiments, the heating panel may not be sent the set point for the room. In such an embodiment, the sensed room temperature is received by the central heating control centre and used by the centre to determine the temperature to which the heating panel should be set. This temperature is then sent to the heating panel and the temperature of the heating panel is adjusted such that is matches the temperature sent by the heating control centre.

Tile central heating control centre may be used to monitor and adjust the temperature in other types of rooms in the facility as well. For example, there may be set-points defined for communal areas, such as the lobby and restaurant, and function rooms. These rooms may not require occupancy dependent set-points. Communal areas may have set-points defined fin specific time periods. For example, the restaurant may have a higher set-point defined for the hours thr which the restaurant is open. Function rooms may have set-points defined for when vacant and booked, similar to the bookable rooms. They may also have set-points defined for different occupancy levels. For example. if a room is booked for a seated event, it is likely to have fewer occupants than a standing event, so require a slightly higher temperature.

In some embodiments, there may be more than one panel heater in a single room. The panel heaters in a single room may be controlled together or they may be individually controlled. Sensors are positioned in the rooms which may be used to determine occupancy and temperature of the room, as disclosed below. There may be a single senor in each room, or there may be multiple sensors in each room. The sensors in the room may communicate with all of the heaters, or they may only communicate with a single heater. By associating each heater with a respective sensor, the heater can adjust its temperature based on the local temperature of the area of the room in which the heater is situated. For example, if the heater is positioned near a drafty window, the local temperature may be lower than that of a heater positioned in the middle of the room. The sensor would detect the temperature and send this data either to the panel heater or to the central heating control sensor. The heater near the window would then have to increase its temperature to a higher temperature than that in the middle of the room in order to maintain a set point temperature.

Possible set points for the current state of the room may be sent to the heating panel from a LI via the mesh network. For example, if it is determined that the room is booked, both the occupied and unoccupied occupancy set points are transmitted to the heating panel. The occupancy sensor determines if the room is occupied and transmits this information to the heating panel. The heating panel uses this received information to determine which of the two set points to use.

The sensed room temperature may also be transmitted to the central heating control centre, either by the heating panel or directly by the temperature sensor.

in such an arrangement, the sensed room temperature is received by the central heating control centre and used by the centre to determine the temperature to which the heating panel should be set. This temperature is then sent to the heating panel and the temperature of the heating panel is adjusted such that it matches the temperature sent by the heating control centre.

It will be appreciated that the control system described herein may be used to control appliances other than panel heaters. For example, it may be used to control air conditioning in a room, whereby different temperatures and intensities of air conditioning are defined for rooms in different states and occupancies. Alternatively, the system may control the lighting in a room, for example the brightness of the lights and which/how many lights are on may be defined by the set points for the different room state and occupancy combinations. Other appliances may also be controlled. In such embodiments, there is still a central control centre which is used to determine the relevant set point(s) based on the data received from the booking system.

It will also be appreciated that the environment sensors may comprise sensor types other than those disclosed herein. For example, a noise sensor may be used to detect occupants in a room. The type of sensors required may depend on the appliance which is to be controlled. The data collected by the environment sensors may be used to control more than one appliance type in the room in which the sensor is situated. For example, the sensor may transmit data back to the central control centre which is used to determine whether to turn the lights on as well as transmitting data to the panel heater so that it can determine the set point temperature it should be using.

Application Protocol An application protocol defines the commands which can be sent and received by the local units, and thus used to control the local units. This protocol is device type specific, such that the commands for controlling different appliances are different.

The commands which can be implemented by an appliance are defined by the appliance, The system described herein may be used with existing appliances. This is advantageous since it allows facilities to benefit from the system without the additional cost of purchasing new appliances. It also means that the methodology behind the system may he transferred to different appliances, so creating a more flexible control system.

An example of an application protocol is given above in the example of heating control commands. Such commands are setpoint overrides, maximum and minimum setpoint restriction, and occupancy state oven-ides. A setpoint override is a command sent when the occupant of a room adjusts the temperature of the panel heater to one which differs from the setpoint defined at the control centre. Maximum and minimum setpoint restriction commands are sent when a maximum or minimum temperature respectively has been defined at the control centre, and an occupant attempts to after the temperature of their panel heater such that it exceeds or is less than the restriction respectively. The occupancy state as determined by the sensors may he overridden is certain situations. For example, while occupants are sleeping, there would be no movement in the room, so the sensor data would determine that the room were unoccupied. An override may be sent to the sensors during predefined times such that they are not used for determining occupancy.

User Interface The central heating control centre may comprise a user interface, through which the person responsible for the heating control in the room(s), referred to herein as the heating control user, may control the set points and monitor the state of each room. Each room in the hotel may be associated with its own dashboard at the control centre. This allows the heating control user to modify the set points of each room individually. Some rooms may be grouped into sets, such that their heaters are controlled together. Each room may contain more than one heater. There may be provided a separate control dashboard for each heater in the room, or they may be grouped such that a single control, dashboard ter a single room is used to determine the set points for all heaters of the whole room.

The control dashboard for a room can be used by the heating control user to input the desired set points for the heater(s) in the room. There may also be displayed the current room temperature as sensed by the environment sensors, the status of the room as determined from the booking system, and/or the occupancy of the room as determined by the occupancy sensors. The information may be provided to the heating control user in any viewable format. The control dashboard may present other information to the heating control user in addition to or instead of the above-mentioned information.

Data regarding a whole site or multiple sites may be displayed to the heating control users via the portal. Figure 4 shows an example of a multiple site dashboard 4()O. The user is presented with the average room power 402 used at each site in both list and graphical form. He is also presented with the average room temperature 404 in each of the sites of the facility in both list and graphical form.

Figure 5 shows an example of a site dashboard 500. Each room of the site is presented in a list 502 with its corresponding communication status 504. The communication status 504 indicates if the-panel heater is online or offline, and how long it has been offline. A panel heater is offline ii it is unable to communicate with the central heating control centre. This may be because the panel heater is not receiving power, i.e.it is switched off, or there may be no suitable communication route for the panel heater to use for communicating with the control centre. The communication network is described later.

The heating control user may also be presented with average data for the site on the site dashboard 500. For example, he may be presented with an average room temperature 506, an average room power usage 508, a hot water flow 510, a hot water return 512, and/or a cold water feed 514.

The collected average data may be used by the heating control user to identify inefficiencies in the energy usage in the sites, or identify areas for improvement.

Figure 6 shows an example panel heater dashboard 600. The panel heater in question is associated with room 102., as indicated by the panel heater ID 602. The communication status 504 of the panel heater is displayed. The occupancy status 604 is also displayed. It will be appreciated that other information may be displayed on the panel heater dashboard 600 instead of or as well as the data shown in Figure 6. For example, the room state may be displayed to the heating control user. The pre-defined set points may also be displayed. The set-point which is being implemented in the room at. the present time may also be displayed.

Figure 6 shows the power usage by the panel heater arid temperature of the room over time 606. It also shows the state of the panel heater over time 608, that is, whether the panel heater is on or off. It will be appreciated that other data may be collected over time and displayed on the panel heater dashboard 600. For example, the implemented set-points may be shown. Figure 6 shows collected data over a period of 12 hours. The heating control user may be able to alter the time period for which data is displayed.

The data presented to the heating control user via the portal may be updated at predefined time intervals. For example, the electricity meter data may he gathered and updated every half an hour, and the environment sensor collected data, for example the occupancy and room temperature, may be reported quarter hourly. It will be appreciated that other time intervals may be used. The time intervals may be determined by the accuracy of the monitoring data required.

Different heating control users may be granted different levels of access to the central control centre. Some heating control users may, for example, only be able to view the data, whereas others may be able to edit some or all of the controllable data. Each heating control user may be given his own log-in. Multiple custom dashboards may be generated and assigned to the users with different levels of access.

In the context of controlling appliances, the feral 'room' may refer to a single room, for example. a bedroom, or it may refer to the set of rooms which are booked in a single booking, for example both the bedroom and bathroom which form part of 'Room 204'. That is, the bathroom, for example, may have different set points to the bedroom in the first instance, hut the same in the second. For determining the state of a room, the term 'room' refers to the set of rooms which cannot be booked separately.

Advantages of the Communication System The system disclosed above has a number of advantages.

The system is easy to install. The boards used in the panel heaters in order to connect them to the mesh network, i.e. so they can communicate with the gateway, are designed to fit into the panel heaters as they currently exist. The boards replace those which have been designed by the panel heater manufacturer to allow users to remotely control the heater via a mobile application. The controllers can be easily swapped between panel heaters. For example, if a panel heater is replaced, the controller can simply be removed from the old panel heater an inserted into the new one. There is no need for a qualified electrician to install the controller, nor do new controllers need to be purchased for replacement panel heaters.

Occupancy sensors need not he hardwired. They communicate with the panel heaters and/or the gateway via LoRa, or any other chosen communication means. This reduces the installation time and costs. It also allows the sensors to be placed anywhere in the room, reducing the effect on aesthetics both through their chosen placement location and lack of required wiring.

The central heating control system allows a facility to have more control over their energy usages. This system may help the facility reduce energy consumption and costs. By lowering the temperature of rooms when they are unoccupied or vacant, energy is not wasted. By starting to heat the room when its booking state changes from vacant to booked, the room temperature will have risen slightly by the time the occupant arrives at the room. This will prevent the occupant from excessively adjusting the temperature upon entering the room. It also provides a room of more comfortable temperature to the occupant upon arrival. The central heating control system provides a balance of suitable room temperature and energy consumption.

The system is also transferable. That is, it is not appliance specific. The application protocol, that is the commands used to control the appliances, varies depending on the appliance, hut the communication system mesh, including the headers used, routing, timing, and encryption, and the radio protocol used are appliance independent. As discussed above, this also allows the system to be used with appliances which are already owned by and installed in the facility, so reducing their costs and installation time. Only modifications to the commands used by the central control centre need to be implement. Thus, the system is flexible.

Additional Qptions The central control system and central control centre may be used to control a condition other than temperature. For example, the control centre may be used to control lighting. In such an example, the panel heaters of the disclosed system would be replaced by lights. The control of temperature as disclosed is merely an example application.

The control system described herein may be used to control appliances other than panel heaters. For example, it may be used to control air conditioning in a room, whereby different temperatures and intensities of air conditioning are defined for rooms in different states and occupancies. Alternatively, the system may control the lighting in a room, for example the brightness of the lights and whichihow many lights are on may be defined by the set points for the different room state and occupancy combinations. Other appliances may also be controlled. In such embodiments, there is still a central control centre which is used to determine the relevant set point(s) based on the data received from the booking system.

The sensors may comprise sensor types other than those disclosed herein. For example, a noise sensor may be used to detect occupants in a room. The type of sensors required may depend on the appliance which is to be controlled. The data collected by the environment sensors may be used to control more than one appliance type in the room in which the sensor is situated. For example, the sensor may transmit data back to the central control centre which is used to determine whether to turn the lights on as well as transmitting data to the panel heater so that it can determine the set point temperature it should be using.

Other appliances may be additionally used as nodes, for example, the environment sensors, electrical appliance control units, or boilers.

The system may be used to control multiple different appliance types simultaneously. For example, the central heating control system may control both panel heaters and air conditioning units. The current season and/or local weather may determine whether the set-point is put into effect by the panel heater or by the air conditioning unit.

In some embodiments, the system is not used to control devices. It may, instead be used to collect information. For example, the system may be used to collect electricity meter readings from a collection of electricity meters. The meters may comprise local units, which transmit the data packets via routes in the mesh as described above. The electricity meter may receive a request for information from a central control centre. In response to the request, the electricity meter may send the information as a signal back to the central control centre, via the gateway and along the determined route. Alternatively, the electricity metres may send their data packets at a pre-determined time. In each case, the central control centre may respond to the receival of the transmitted data by sending an acknowledgment signal, as above. The electricity meter can determine whether or not to retry transmitting its data packet based on whether the acknowledgment signal is received. It will be appreciated that an electricity meter is used as an example only, and that other data collection devices may transmit data using the above described network and method.

Other variations and applications of the disclosed techniques may become apparent to the person skilled in the art once Riven the disclosure herein. The scope of the present disclosure is not limited by the above-described embodiments, but only by the accompanying claims.

Claims (31)

1. Claims: A radio communication system for installation in a facility, the system comprising: at least one gateway unit configured to transmit and receive messages according to a radio communication protocol; a plurality of local units each configured to monitor and/or control a respective local environment within the facility and to transmit and receive messages according to the radio communication protocol, each local unit configured to: execute a route scan by transmitting a broadcast scan message; detect responses from at least some in-range local or gateway units, each response identifying the responding local or gateway unit and the number of hops of each responding local unit from the gateway unit; and determine a route for subsequent transmission from the local unit to the at least one gateway based on the number of hops.
2. 2. A radio communication system according to claim 1, wherein each local unit is configured to periodically transmit a data message over the determined route and await a gateway acknowledgement message.
3. 3. A radio communication system according to claim 2, wherein each local unit is configured to use the determined route is used until a configurable number of failed transmissions have been attempted.
4. 4. A radio communication system according to any preceding claims, wherein the messages are encrypted end-to-end. 34.
5. 5. A radio communication system according to any of claims 2 to 4, wherein the data message includes a header identifying the gateway and any intervening local devices to define the route.
6. 6. A radio communication system according to any preceding claim, wherein each local unit is configured to transmit data messages in respective designated timeslots common to a group of local units wherein each local unit is configured to select randomly a transmission time within the designated timeslot.
7. 7. A radio communication system according to claim 6, wherein the random transmission time is selected by dividing the times,lot into a numbered sequence of sub-slots and randomly selecting a number to thereby select one of the sub-slots.
8. 8. A radio communication system according to any preceding claim, wherein the at least one local unit is mounted on a control board of one or more temperature control device.
9. 9. A radio communication system according to claim 8, wherein the temperature control device is a panel heater.
10. 10. A radio communication system according to claim 8, wherein the temperature control device is an air-conditioning unit.
11. 11. A radio communication system according to any of claims 1 to 7, wherein at least one local unit is mounted on an environment sensor.
12. 12. A radio communication system according to any preceding claim, wherein the gateway is configured to issue control command messages for reception at at least some of the local units.
13. 13. A radio communication system according to claims 8 and 12, wherein the local units are configured to respond to the control command messages to control the local environment.
14. 14. A radio communication system according to any preceding claim, wherein at least one of the local units is configured to transmit to the gateway a detected occupancy status of a room in which the said local unit is located.
15. 15. A radio communication system according to claims 12 and 14, wherein the gateway is configured to issue a control command message based on the detected occupancy status.
16. 16. A radio communication system according to any of claims 14 and 15, wherein the detected occupancy status is set for a period of time following the detection.
17. 17. A radio communication system according to claim 13, wherein the control command message comprises a determined set point from a plurality of pre-defined set points, the determined set point determined by a vacancy status of the room.
18. 18. A radio communication system according to claim 17, wherein the vacancy status is determined based on a facility booking system.
19. 19. A radio communication system according to any of claims 17 and 18, wherein the pre-defined set points comprise a minimum set point for cooling and/or a maximum set point for heating.
20. 20. A radio communication system according and of claims 8 and 11, wherein the local sensor unit and the local control unit are paired via encryption, wherein the control unit is configured to transmit messages to the gateway.
21. 21. A local unit for communicating with a gateway within a radio communication system for installation in a facility having multiple local units, the local unit configured to monitor and/or control a respective local environment within the facility and to transmit and receive messages according to a radio communication protocol, the local unit configured to: execute a route scan by transmitting a broadcast scan message using radio modulation; detect responses from at least some in-range local or gateway units, each response identifying the responding local or gateway unit and the number of hops of each responding local unit from the gateway unit; and determine a route for subsequent transmission from the local unit to the at least one gateway based on the number of hops.
22. 22. A local unit according to Claim 21 comprising one of: a panel heater; an air-conditioning unit; and an environment sensor.
23. 23. A system for controlling an environment, the system comprising: an electronic booking system of a facility for storing, a vacancy status associated with a room of the facility: a central controller configured to receive from the electronic booking system the vacancy status of the room and select an environment set-point from a plurality of environment set-points based, at least in part, on the received vacancy status, the environment set-points defining a desired current room environment state; an environment contioller located in the room for controlling a current environment state comprising a first local unit, the first local unit configured to receive from the central controller the selected environment set-point; and an environment sensor comprising a second local unit located in the room, the environment sensor configured to determine the current environment state and the second local unit configured to transmit the current environment state to the first local unit of the environment controller; wherein the environment controller is configured to determine and implement an environment controller setting based on the received selected environment set-point and the transmitted current environment state.
24. 24. A system according to claim 23, wherein the current environment state is the temperature of the room, and the environment set-points define different temperatures.
25. 25. A system according to any of claims 23 or 24, wherein the environment controller setting is a temperature at which the environment controller is to be set.
26. 76. A system according to any of claims 23 to 25, wherein the environment controller is one of a panel heater or an air conditioning unit.
27. 27. A system according to any of claims 23 to 26, wherein the system comprises a plurality of environment controllers, each environment controller located in a different room of the facility and each comprising a first local unit.
28. 28. A system according to any of claims 23 to 27, wherein the first local unit receives the selected environment set-point from the central controller via a gateway unit, the gateway unit configured to transmit and receive messages according to a radio communication protocol.
29. 29. A system according to any of claims 23 to 28, wherein the first and second local units are configured to transmit and receive messages according to a radio communication protocol.
30. 30. A central controller for controlling a current environment state of a room in a facility, the central controller configured to: receive from an electronic booking system a vacancy status associated with the room; select, based at least in part on the received vacancy status, an environment set-point from a plurality of environment set-points, the environment set-points defining a desired current room environment state; and transmit to a local unit of an environment controller located in the room the selected environment set-point, the environment controller for controlling the current environment state and configured to determine and implement an environment controller setting based, at least in part, on the received selected environment set-point.
31. 31. A radio communication system according to claim 1 or a local unit according to claim 21 wherein each response further indicates a signal strength.