Patent Description:
A lighting system applied for illuminating a space, e.g. a building or an outdoor area, typically comprises a plurality of luminaires that operate based at least in part on observations of one or more environmental characteristics in the space the lighting system serves to illuminate, e.g. on sensor data obtained via one or more occupancy sensors and/or one or more light sensors arranged in the space. The luminaires and the sensors may be communicatively coupled to each other via a wireless or wired communication network, the luminaires and sensors hence serving as nodes of a lighting control network that enables a node of the lighting control network to share information of its operational status with other nodes of the lighting control network and to obtain information of operational status of other nodes of the lighting control network to facilitate lighting control. Such sharing of status information enables timely and efficient control in the luminaires of the lighting system.

The status information shared within the lighting control network may be useful information for controlling other services or functions available in the space, such as HVAC and/or other building automation. On the other hand, integrating entities of such external services into the lighting control network as nodes of the lighting control network runs a risk of compromising security and reliability of the lighting control, whereas coupling entities of such other services to the lighting control network via a gateway typically requires laborious manual configuration of the gateway functionality while it necessarily leads into an inflexible approach that is tailored to a specific pair of a lighting control network and an external system.

In related art, <CIT> discloses a lighting network where control of the lighting fixtures in the network may be distributed among the lighting fixtures. The lighting fixtures may be broken into groups that are associated with different lighting zones. Certain lighting fixtures will have or be associated with one or more sensors, such as occupancy sensors, ambient light sensors, and the like. Within the lighting network or the various lighting zones, lighting fixtures may share sensor data. Each lighting fixture may process sensor data provided by its own sensor, a remote standalone sensor, or lighting fixture, and process the sensor data according to the lighting fixture's own internal logic to control operation. The lighting fixtures may also receive control input from other lighting fixtures, control nodes, light switches, and commissioning tools. The control input may be processed along with the sensor data according to the internal logic to further enhance control of the lighting fixture.

It is an object of the present invention to provide a lighting control network and a node of such lighting control network that enable sharing of status information with an entity external to the lighting control network in a manner that does not compromise integrity of the lighting control network while allows for flexible interoperation with the element external to the lighting control network.

According to an example embodiment, a control apparatus for a node of a first network that is arranged to communicatively couple, to each other, a plurality of nodes, wherein said plurality of nodes comprise a plurality of luminaires arranged for illuminating one or more spaces is provided, the apparatus comprising: a communication portion for communicating with other apparatuses via the first network and a second network; and a control portion arranged to: derive, based on one or more occupancy states that are associated with the node, a node occupancy state that pertains to a location of the node within the one or more spaces and indicates one of occupancy or non-occupancy at the location of the node; receive, via the first network, one or more status indications originating from other ones of the plurality of nodes of the first network, wherein said status indications are indicative of respective occupancy states at respective locations of said other ones of the plurality of other nodes; derive, based on said one or more status indications, at least one regional occupancy state such that each regional occupancy state pertains to a respective plurality of other locations within the one or more spaces and indicates one of occupancy or non-occupancy at the respective plurality of other locations; and broadcast, via the second network to one or more external apparatuses that are external to the first network, a network occupancy status message that indicates the node occupancy state and the at least one regional occupancy state.

According to another example embodiment, a luminaire comprising a control apparatus according to the example embodiment described in the foregoing and at least one light source is provided, wherein the control portion comprises a lighting control portion further arranged to control one or more aspects of light output of the at least one light source.

According to another example embodiment, a method in a node of a first network that is arranged to communicatively couple, to each other, a plurality of nodes, wherein said plurality of nodes comprises a plurality of luminaires arranged for illuminating one or more spaces is provided, the method comprising: deriving, based on one or more occupancy states that are associated with the node, a node occupancy state that pertains to a location of the node within the one or more spaces and indicates one of occupancy or non-occupancy at the location of the node; receiving, via the first network, one or more status indications originating from other ones of the plurality of nodes of the first network, wherein said status indications are indicative of respective occupancy states at respective locations of said other ones of the plurality of other nodes; deriving, based on said one or more status indications, at least one regional occupancy state such that each regional occupancy state pertains to a respective plurality of other locations within the one or more spaces and indicates one of occupancy or non-occupancy at the respective plurality of other locations; and broadcasting, via a second network to one or more external apparatuses that are external to the first network, a network occupancy status message that indicates the node occupancy state and the at least one regional occupancy state.

According to another example embodiment, a computer program is provided, the computer program comprising computer readable program code configured to cause performing at least a method according to an example embodiment described in the foregoing when said program code is executed on a computing apparatus.

The computer program according to the above-described example embodiment may be embodied on a volatile or a non-volatile computer-readable record medium, for example as a computer program product comprising at least one computer readable non-transitory medium having the program code stored thereon, which, when executed by one or more computing apparatuses, causes the computing apparatuses at least to perform the method according to the example embodiment described in the foregoing. The exemplifying embodiments of the invention presented in this patent application are not to be interpreted to pose limitations to the applicability of the appended claims. The verb "to comprise" and its derivatives are used in this patent application as an open limitation that does not exclude the existence of also unrecited features.

Some features of the invention are set forth in the appended claims. Aspects of the invention, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of some example embodiments when read in connection with the accompanying drawings.

<FIG> illustrates a block diagram of some components of a lighting system <NUM> according to an example. The lighting system <NUM> may be arranged for illuminating one or more spaces, e.g. one or more indoor spaces and/or one or more outdoor spaces. The lighting system <NUM> as illustrated in <FIG> includes luminaires <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM> and <NUM>-<NUM> and an external apparatus <NUM>-<NUM>. The luminaires <NUM>-<NUM> to <NUM>-<NUM> represent a plurality of luminaires <NUM>, where an individual luminaire may be referred to via a reference number <NUM>-k. Each luminaire <NUM>-k may be arranged at a respective location within the one or more spaces for illuminating the respective location of the one or more spaces. The external apparatus <NUM>-<NUM> represents one or more external apparatuses <NUM>, where an individual external apparatus may be referred to via a reference number <NUM>-j. The external apparatuses <NUM>-j comprise respective elements of another device, system, service or function available in said one or more spaces, e.g. those of an HVAC system, an alarm system, an elevator system, etc..

The luminaires <NUM>-k may be communicatively coupled to each other via a first network, which may be also referred to as a lighting control network. Hence, each luminaire <NUM>-k may be considered as a respective node of the first network, which serves to interconnect the luminaires <NUM>-k as the lighting control network. While the illustration of <FIG> suggests wireless communication between the luminaires <NUM>-k, the first network may comprise a wireless communication network, a wired communication network or bus, or a combination of a wireless communication network and a wired communication network or bus.

At least one of the luminaires <NUM>-k may be further communicatively coupled to at least one of the one or more external apparatuses via a second network that is separate from the first network. The second network may comprise a wireless communication network and it may be also referred to as an external network. Hence, there may be a communicative coupling between an individual node of the first network and an external apparatus <NUM>-j, while this coupling is separate from the first network and it does not render the respective external apparatus <NUM>-j as a node of the first network.

<FIG> illustrates a block diagram of some components of the luminaire <NUM>-k according to an example. The luminaire <NUM>-k may comprise at least one light sources <NUM>-k and a lighting control apparatus <NUM>-k that comprises a lighting control portion <NUM>-k for controlling at least some aspects of the light output of the at least one light source <NUM>-k and a communication portion <NUM>-k for wireless and/or wired communication with other apparatuses. The luminaire <NUM>-k may further comprise a sensor portion <NUM>-k that includes one or more sensors for observing respective environmental characteristics at the location of the luminaire <NUM>-k, e.g. in the location of the one or more spaces the luminaire <NUM>-k serves to illuminate. The sensor portion <NUM>-k comprises at least an occupancy sensor for monitoring occupancy at the location of the luminaire <NUM>-k and it may comprise one or more further sensors, e.g. a light sensor for monitoring ambient light level at the location of the luminaire <NUM>-k. As a non-limiting example, the occupancy sensor may comprise a motion sensor such as passive infrared (PIR) sensor, whereas in other examples of the occupancy sensor may comprise a microwave radar, a (digital) camera, a thermographic camera, a microphone, a lidar, etc. whereas the light sensor, if included in the sensor portion <NUM>-k, may comprise a photodetector such as a photodiode.

The luminaire <NUM>-k or an element thereof may have a luminaire identifier (ID) or a device ID assigned thereto, e.g. an address, a serial number, a name, etc. assigned to the luminaire <NUM>-k or to an element thereof. The luminaire ID may be stored, for example, in a memory provided in the lighting control apparatus <NUM>-k or in another component of the luminaire <NUM>-k. The luminaire ID assigned to the luminaire <NUM>-k may be applied in communication with other nodes of the lighting control network, as described in the following.

The luminaire <NUM>-k may be assigned to a luminaire group with one or more other ones of the plurality of luminaires <NUM>. Luminaires assigned to the same luminaire group are, typically but not necessarily, installed in locations that are relatively close to each other and they may hence serve to illuminate the same portion or respective adjacent portions of the one or more spaces. In terms of lighting control, at least one aspect of operation of those luminaires <NUM>-k that are assigned to the same luminaire group may be dependent on a lighting control action carried out by another luminaire of the same luminaire group. Moreover, an external control entity that may be coupled to the lighting control network may address and/or control the luminaires <NUM>-k of the same group via a single lighting control action or configuration action.

A luminaire group may be identified by a luminaire group ID assigned thereto. The luminaire group ID may be stored, for example, in the memory provided in the lighting control apparatus <NUM>-k or in another component of the luminaire <NUM>-k. The luminaire group ID assigned to the luminaire <NUM>-k may be applied in communication with other nodes of the lighting control network, as described in the following. Alternatively or additionally, the luminaire <NUM>-k may a have respective luminaire IDs of the other ones of the plurality of luminaires <NUM> that are assigned in the same luminaire group with the luminaire <NUM>-k stored in the memory therein, thereby enabling identification of other luminaires of the same luminaire group based on their luminaire IDs. The information about the luminaire group in which the luminaire <NUM>-k belongs to (e.g. the luminaire group ID and/or the respective luminaire IDs of the other luminaires of the luminaire group) may be set or defined e.g. upon installing, configuring or reconfiguring the lighting control apparatus <NUM>-k and/or the luminaire <NUM>-k, or this information may be received at the lighting control apparatus <NUM>-k, e.g. from an external control entity, in the course of operation of the luminaire <NUM>-k.

According to an example, the at least one light source <NUM>-k comprises one or more light emitting diodes (LEDs) and the lighting control apparatus <NUM>-k comprises or is provided as a LED driver device, whereas in another non-limiting example the at least one light source <NUM>-k comprises one or more fluorescent lamps and the lighting control apparatus <NUM>-k comprises or is provided as an electronic ballast.

The lighting control portion <NUM>-k may be arranged to control one or more aspects of light output of the at least one light source <NUM>-k in accordance with a predefined lighting control logic that defines one or more lighting control rules. Each lighting control rule may define a respective pair of a triggering condition and a lighting control action to be carried out in response to an occurrence of the triggering condition. A lighting control rule may optionally have one or more lighting control parameters associated therewith. As an example, a lighting control rule may define a triggering condition that directly or indirectly pertains to one or more sensor signals obtained from the sensor portion <NUM>-k provided locally at the luminaire <NUM>-k, e.g. an occupancy sensor signal and/or a light sensor signal. In the course of its operation, the lighting control portion <NUM>-k may capture or derive local occupancy state indications (i.e. respective indications of one of occupancy or non-occupancy) based on the occupancy sensor signal received from the occupancy sensor of the sensor portion <NUM>-k and/or derive local light level indications based on the light sensor signal received from the light sensor of the sensor portion <NUM>-k. Herein, the local occupancy state may be considered as an occupancy state that is (directly) associated with the luminaire <NUM>-k.

In the following, lighting control actions arising from application of the lighting control logic are predominantly described as operations carried out by the lighting control portion <NUM>-k. As an example, the lighting control logic may define one or more of the following lighting control rules:.

Moreover, in case the occupancy state remains unchanged, the lighting control logic may comprise respective lighting control rules for keeping the light output of the luminaire <NUM>-k unchanged in response to continued occupancy and/or in response to continued non-occupancy.

The target light intensity Itgt,k, the intermediate light intensity Iint,k and the stand-by light intensity Ioff,k as well as the switch-off delay period Toff,k, the dim-down delay period Tdim,k described above serve as non-limiting examples of lighting control parameters that may be defined for the lighting control rules of the lighting control logic and they may have respective values set upon manufacturing, configuring or reconfiguring the lighting control apparatus <NUM>-k and/or the luminaire <NUM>-k.

As described in the foregoing, the communication portion <NUM>-k may enable wired or wireless communication between the lighting control apparatus <NUM>-k and other apparatuses via the lighting control network (the first network) and/or via the external network (the second network). In this regard, the communication portion <NUM>-k may comprise one or more communication apparatuses that enable communication via the lighting control network and/or via the external network. In an example, the communication portion <NUM>-k may comprise a single communication apparatus that enables wireless communication via the lighting control network and via the external network. In another example, the communication portion <NUM>-k may comprise a first communication apparatus that enables wireless or wired communication via the lighting control network and a second communication apparatus that enables wireless communication via the external network.

A communication apparatus of the communication portion <NUM>-k that enables wireless communication may comprise a wireless transceiver that is capable of communicating with wireless transceivers provided in other apparatuses using a wireless communication technique or protocol. The wireless communication may be provided by using a suitable short-range wireless communication technique known in the art that enables communication over ranges from a few meters up to a few hundred meters. Examples of suitable short-range wireless communication techniques include Bluetooth, Bluetooth Low-Energy (BLE), ZigBee, WLAN/Wi-Fi according to an IEEE <NUM> family of standards, etc. The choice of the wireless communication technique and network topology applied for a specific implementation of the lighting control network and/or the external network may depend e.g. on the required communication range and/or requirements with respect to energy-efficiency of the communication apparatuses.

In the following examples, some aspects of operation of the luminaire <NUM>-k and its components are described with assuming application of a wireless communication technology for providing the lighting control network that serves to communicatively couple the plurality of luminaires <NUM> to each other, whereas an example that describes some aspects that may be specific to using wired communication to provide the lighting control network are provided later in this text. As a concrete non-limiting example of applicable wireless communication technology, the lighting control network may be provided using a wireless mesh network model, for example on a mesh network according to the Bluetooth or BLE Mesh networking protocol known in the art, whereas the external network may be provided using BLE communication independently of the lighting control network, e.g. via usage of BLE advertising channel protocol data units (PDUs). Without losing generality, in the following examples the BLE mesh and the BLE advertising channel PDUs are applied as respective examples of the lighting control network and the external network, where applicable.

The lighting control portion <NUM>-k may operate the communication portion <NUM>-k to transmit, via the lighting control network, status indication messages to the other nodes of the lighting control network. A status indication message may comprise a header part including information defined and/or required by the applied communication protocol and a payload part comprising one or more status indications that are descriptive of current (or recent) operating characteristic of the luminaire <NUM>-k and/or the lighting control apparatus <NUM>-k transmitting the status indication message. Conversely, the lighting control apparatus <NUM>-k receives, via the lighting control network, status indication messages (and hence status indications) from other ones of the plurality of luminaires <NUM> and from possible other nodes of the lighting control network. A status indication transmitted from the lighting control apparatus <NUM>-k may comprise, for example, one of the following:.

A status indication message may comprise timing information that indicates the capturing time(s) of the status indication(s) included in the status indication message, e.g. one or more timestamps that indicate the time with respect to a predefined reference time, included in the payload part of the status indication message. A status indication message may further comprise the device ID assigned to the lighting control apparatus <NUM>-k (or to the luminaire <NUM>-k) that has transmitted the status indication message, in other words an identification of the luminaire <NUM>-k to which the status indication(s) conveyed in the status indication message pertain. The device ID may be provided, for example, as part of the header part of the status indication message or it may be included in the payload part of the status indication message. Additionally, if the luminaire <NUM>-k is assigned to a luminaire group, the payload part of a status indication message transmitted from the luminaire <NUM>-k may comprise the luminaire group ID of the luminaire group to which the luminaire <NUM>-k is assigned.

The status indications received in the status messages may serve as basis for one or more further lighting control rules for the lighting control portion <NUM>-k. An example in this regard comprises a lighting control rule that defines switching on the light output of the luminaire <NUM>-k at the target light intensity Itgt,k or otherwise adjusting the light output of the luminaire <NUM>-k from a lower light intensity to the target light intensity Itgt,k as a response to another luminaire in the same luminaire group indicating a change of the occupancy state therein from non-occupancy to occupancy. The lighting control portion <NUM>-k may derive an occupancy state pertaining to another luminaire of the same luminaire group e.g. via the one or more of the following events:.

Along similar lines, the lighting control logic at the lighting control portion <NUM>-k may include one or more lighting control rules that are responsive to a change of the occupancy state from occupancy to non-occupancy in one or more other luminaires that are assigned to the same luminaire group with the luminaire <NUM>-k. An example in this regard comprises a lighting control rule that defines adjusting the light output of the luminaire <NUM>-k to the stand-by light intensity Ioff,k as a response to none of the luminaires of the same luminaire group with the luminaire <NUM>-k having indicated occupancy within a predefined time period. The lighting control portion <NUM>-k may derive an occupancy state pertaining to another luminaire in the same luminaire group e.g. via the one or more of the following events:.

Hence, in the above scenario the lighting control in the lighting control portion <NUM>-k partially relies on respective occupancy states in one or more other luminaires that are assigned to the same luminaire group with the luminaire <NUM>-k, which occupancy states may be considered as respective occupancy states that are (indirectly) associated with the luminaire <NUM>-k.

In another example, instead of considering the occupancy states derived for the other luminaires in a separate lighting control rule, a similar functionality may be provided via replacing the local occupancy state derived at the lighting control portion <NUM>-k based on the occupancy sensor signal received from the sensor portion <NUM>-k by a group occupancy state in application of the above-described lighting control rules that rely on the local occupancy state. The group occupancy state may be derived based on all occupancy states that are associated with the luminaire <NUM>-k, i.e. on the local occupancy state derived on basis of the occupancy sensor signal received from the sensor portion <NUM>-k and on the respective occupancy states derived for the other luminaires in the same luminaire group, e.g. such that the group occupancy state may be set to indicate occupancy in case any of the luminaires assigned to the group indicates occupancy and set to indicate non-occupancy in case none of the luminaires assigned to the group indicates occupancy. In this regard, determination of the group occupancy state may consider, for each of the luminaires involved, the respective most recently derived occupancy state.

Since reception of the status messages at the lighting control apparatus <NUM>-k is not restricted to status messages originating from those ones of the plurality of luminaires <NUM> that are assigned to the same luminaire group with the luminaire <NUM>-k but the lighting control apparatus <NUM>-k basically may derive occupancy indications pertaining to any of the other luminaires of the lighting system <NUM> e.g. via one or more of the following events:.

Consequently, in the course of operation of the lighting system <NUM> the lighting control portion <NUM>-k may obtain knowledge of respective occupancy states pertaining to respective ones of the plurality of luminaires <NUM>. In this regard, respective status messages originating from other ones of the plurality luminaires <NUM> received at the lighting control apparatus <NUM>-k serve to provide respective indications of occupancy states derived at their respective locations within the one or more spaces the lighting system <NUM> serves to illuminate. In particular, status messages originating from a lighting control apparatus <NUM>-n of a luminaire <NUM>-n serve to provide respective
indications of occupancy states derived at its location within the one or more spaces. In viewpoint of the lighting control apparatus <NUM>-k and the lighting control portion <NUM>-k therein, the (local) occupancy state derived at the lighting control apparatus <NUM>-n may be considered as a remote occupancy state pertaining to the location of the luminaire <NUM>-n.

Consequently, in the course of operation of the lighting system <NUM> the lighting control portion <NUM>-k continually obtains the following knowledge of occupancy states in various locations within the one or more spaces the lighting system <NUM> serves to illuminate:.

In addition to or instead of making use of the knowledge of the occupancy states in other luminaires of the same luminaire group with the luminaire <NUM>-k for lighting control at the lighting control portion <NUM>-k, the occupancy states pertaining to the other one of the plurality of luminaries <NUM> may serve as basis for controlling operations and procedures of different kind, for example, in the lighting control apparatus <NUM>-k and/or in the one or more external apparatuses <NUM>. As an example in this regard, the lighting control portion <NUM>-k shares at least part of the occupancy information available therein with the one or more external apparatuses <NUM> e.g. by operating the communication portion <NUM>-k to broadcast, via the external network, network occupancy status messages that indicate a node occupancy state that pertains to the location of the luminaire <NUM>-k and at least one regional occupancy state that pertains to one or more further locations within the one or more spaces the plurality of luminaires <NUM> serves to illuminate, where the one or more further locations may include respective locations of one or more other ones of the plurality of luminaires <NUM>. Typically, but not necessarily, the one or more further locations exclude the location of the luminaire <NUM>-k and are hence locations other than the location of the luminaire <NUM>-k. Non-limiting examples of derivation of the node occupancy state and the at least one regional occupancy state based on occupancy information acquired at the lighting control portion <NUM>-k are provided in the following. The network occupancy status message provides its recipient with information concerning occupancy within the one or more spaces at two or more levels, e.g. at the location of the luminaire <NUM>-k and within a wider area that (also) includes one or more locations further away from the luminaire <NUM>-k, thereby enabling the recipient of the network occupancy status message that is located in proximity of the luminaire <NUM>-k to adjust or adapt its operation by taking into account presence of one or more persons in its both in its immediate vicinity and further away within the one or more spaces.

In an example, the node occupancy state may include the most recent local occupancy state derived at the lighting control portion <NUM>-k, whereas in another example the node occupancy state may include the group occupancy state described in the foregoing, e.g. one derived in the lighting control portion <NUM>-k based on the most recently derived local occupancy state and further based on the respective remote occupancy states derived for the other luminaires in the same luminaire group.

In a further example, the node occupancy state may include a proximity occupancy state derived in the lighting control portion <NUM>-k in consideration of proximity of the other ones of the plurality of luminaries <NUM>. In this regard, the lighting control portion <NUM>-k may estimate a distance between the luminaire <NUM>-k and another one of the plurality of luminaires <NUM> based on one or more characteristics of status messages received therefrom. The following examples in this regard refer to distance estimation between the luminaire <NUM>-k and the luminaire <NUM>-n, while these examples readily generalize into distance estimation between the luminaire <NUM>-k and any other one of the plurality of luminaires <NUM>.

In case the lighting control network is a wireless one that relies on a wireless mesh network model such as a BLE Mesh, a status message originating from the luminaire <NUM>-n may be received via one or more intermediate nodes and the status message (or a lower-layer message that carries the status message) may comprise an indication of hop count that indicates the number of hops (i.e. the number of intermediate nodes of the wireless mesh network) between the lighting control apparatuses <NUM>-k and <NUM>-n. Hence, the hop count received in a status message may serve as an indication of the distance between the lighting control apparatuses <NUM>-k and <NUM>-n (and hence between the luminaires <NUM>-k and <NUM>-n). Consequently, the lighting control portion <NUM>-k may estimate the distance between the luminaires <NUM>-k and <NUM>-n based on respective hop counts received in one or more status messages originating from the lighting control apparatus <NUM>-n, e.g. such that the distance is estimated via a hop count value derived as the hop count indicated in a most recently received status message that originates from the lighting control apparatus <NUM>-n or derived based on the respective hop counts indicated in a plurality of status messages originating from the lighting control apparatus <NUM>-n (e.g. as an average or as a median of the respective hop counts indicated in status messages received therefrom over a time period), where increasing hop count value indicates increasing distance from the luminaire <NUM>-k to the luminaire <NUM>-n.

In case the wireless message carrying the status message originating from the lighting control apparatus <NUM>-n is received at the lighting control apparatus <NUM>-k directly from the lighting control device <NUM>-n (i.e. without intermediate nodes), the lighting control portion <NUM>-k may derive a received signal strength indication (RSSI) pertaining to the received status message. Since in this scenario the RSSI derived at the lighting control apparatus <NUM>-k at least in part reflects the distance to the lighting control apparatus <NUM>-n, the RSSI may serve as an indication of the distance between the lighting control devices <NUM>-k and <NUM>-n (and hence between the luminaires <NUM>-k and <NUM>-n). Consequently, the distance between the luminaires <NUM>-k and <NUM>-n may be estimated based on respective RSSIs derived for one or more status messages received at the lighting control apparatus <NUM>-k (directly) from the lighting control apparatus <NUM>-n, e.g. such that the distance is estimated via a RSSI value derived as the RSSI derived for a status message most recently received from the lighting control apparatus <NUM>-n or derived based on the respective RSSIs derived for a plurality of status messages received from the lighting control apparatus <NUM>-n (e.g. as an average or as a median of the respective RSSIs derived for status messages received therefrom over a time period), where decreasing RSSI value indicates increasing distance from the luminaire <NUM>-k to the luminaire <NUM>-n.

The proximity occupancy state may be derived based on respective remote occupancy states of those ones of the other luminaires that are within a predefined distance threshold from the luminaire <NUM>-k, e.g. such that the proximity occupancy state may be set to indicate occupancy in case any of the luminaires within the distance threshold indicates occupancy and set to indicate non-occupancy in case none of the luminaires within the distance threshold indicates occupancy. The remote occupancy state derived for the other luminaires found to be within the distance threshold from the luminaire <NUM>-k may be considered as respective occupancy states that are (indirectly) associated with the luminaire <NUM>. Determination of the proximity occupancy state may consider, for each of the luminaires involved, the respective most recently derived remote occupancy state. The distance measure applied in identifying the other luminaires to be considered in derivation of the proximity occupancy state may comprise the hop count value and/or the RSSI value described above, e.g. such that only those luminaires for which the hop count value is smaller than a predefined hop count threshold (e.g. one or two) and/or for which the RSSI value is larger than a predefined RSSI threshold are considered in derivation of the proximity occupancy state. Along the lines described above, the hop count value and/or the RSSI value pertaining to a given other luminaire may be derived as the hop count and/or the RSSI derived for the most recent status message originating from the respective other luminaire or e.g. as an average or median of the hop counts and/or RSSIs derived based on status messages received from the respective other luminaire over a time periods, whereas the hop count threshold and/or RSSI threshold may be set accordingly.

Regardless of the manner of deriving the node occupancy state for the network occupancy status message, according to an example, the at least one regional occupancy state may comprise a network occupancy state that may be derived in the lighting control portion <NUM>-k based on respective remote occupancy states derived for other ones of the plurality of the luminaires <NUM>. As an example, the network occupancy state may be set to indicate occupancy in case any of the other ones of the plurality of luminaires <NUM> indicates occupancy and set to indicate non-occupancy in case none of the other ones the plurality of luminaires <NUM> indicates occupancy. In this regard, determination of the network occupancy state may consider, for each of the luminaires involved, the respective most recently derived occupancy state.

In other words, derivation of the network occupancy state may consider the plurality of luminaires <NUM> apart from the luminaires considered in derivation of the node occupancy for the same network occupancy status message and, hence, depending on the case, the derivation of the network occupancy state may disregard the local occupancy state derived in the luminaire <NUM>-k, the remote occupancy states derived for the other luminaires in the same luminaire group with the luminaire <NUM>-k and/or the other luminaires that are within the predefined distance from the luminaire <NUM>-k.

In another example, derivation of the at least one regional occupancy state in the lighting control portion <NUM>-k may consider proximity of the other ones of the plurality of luminaries <NUM> e.g. via application of one or more predefined non-overlapping distance ranges for assigning the other luminaires into respective proximity groups based on their distance from the luminaire <NUM>-k and via deriving a respective proximity group occupancy state for each proximity group. Also in this example the distances between the luminaire <NUM>-k and other ones of the plurality of luminaires <NUM> may be defined as the number of hops and/or as the RSSI and the distance thresholds may be defined as respective hop count thresholds and/or RSSI thresholds.

Hence, each proximity group includes those ones of the other luminaires that are within a respective distance range from the luminaire <NUM>-k and the respective proximity group occupancy state may be derived based on respective remote occupancy states derived for those ones of the other luminaires that are included in the respective proximity group. In this regard, the respective proximity group occupancy state may be set to indicate occupancy in case any of the luminaires included in the respective proximity group indicates occupancy and set to indicate non-occupancy in case none of the luminaires that are included in the respective proximity group indicates occupancy, where the determination of the respective proximity group occupancy state may consider, for each of the luminaires involved, the respective most recently derived remote occupancy state.

As in the case of derivation of the network occupancy state, also derivation of the one or more proximity group occupancy states may consider the plurality of luminaires <NUM> apart from the luminaires considered in derivation of the node occupancy for the same network occupancy status message and, hence, depending on the case, the derivation of the one or more proximity group occupancy states may disregard the local occupancy state derived in the luminaire <NUM>-k, the remote occupancy states derived for the other luminaires in the same luminaire group with the luminaire <NUM>-k and/or the other luminaires that are within the predefined distance from the luminaire <NUM>-k.

In a further example, the at least one regional occupancy state may comprise one or more spatial group occupancy states derived in dependence of predefined location information assigned to at least some of the plurality of luminaires <NUM>. As an example in this regard, there may be one or more spatial luminaire groups defined in relation to the location of the luminaire <NUM>-k and the lighting control portion <NUM>-k may derive a respective spatial group occupancy state for each of the spatial groups. As a non-limiting example, the spatial groups may comprise one or more of the following:.

This information may be stored, for example, in the memory provided in the lighting control apparatus <NUM>-kor in another component of the luminaire <NUM>-k and it may be set or defined, for example, upon installing, configuring or reconfiguring the lighting control apparatus <NUM>-k and/or the luminaire <NUM>-k. In another example, this information may be received in the course of operation of the luminaire <NUM>-k via the lighting control network, e.g. from an external control entity or from the luminaires concerned (e.g. as part of the status messages originating therefrom or in response to an information request sent thereto from the lighting control apparatus <NUM>-k).

With access to information that defines the one or more spatial groups, the lighting control portion <NUM>-k may derive the respective spatial group occupancy state for one or more of the spatial groups based on the respective remote occupancy states derived for the luminaires concerned. In this regard, the respective spatial group occupancy state may be set to indicate occupancy in case any of the luminaires included in the respective spatial group indicates occupancy and set to indicate non-occupancy in case none of the luminaires that are included in the respective spatial group indicates occupancy, where the determination of the respective proximity group occupancy state may consider, for each of the luminaires involved, the respective most recently derived remote occupancy state.

In addition to the non-limiting examples of deriving the node occupancy state and the at least one regional occupancy state for the network occupancy status message provided in the foregoing, in other examples various (other) the network occupancy status message include a different combination of one or more of the local occupancy state, the group occupancy state, the proximity occupancy state, the network occupancy state, the one or more proximity group occupancy states and the one or more spatial group occupancy states. As an example in this regard, the node occupancy state may comprise the local occupancy state while the at least one regional occupancy state may comprise the group occupancy state or both the group occupancy state and the network occupancy state. In another example, the node occupancy state may comprise the local occupancy state while the at least one regional occupancy state may comprise the proximity occupancy state or both the proximity occupancy state and the network occupancy state. In a further example, the node occupancy state may comprise one of the local occupancy state, the group occupancy state or the proximity occupancy state while the at least one regional occupancy state may comprise at least one of the following: the network occupancy state, the one or more proximity group occupancy states and the one or more spatial group occupancy states.

In case the sensor portion <NUM>-k includes the light sensor, the network occupancy status message may further include a node light level indication that is descriptive of the ambient light level at the location of the luminaire <NUM>-k. In an example the node light level indication may comprise the current (or the most recent) local light level indication derived in the lighting control portion <NUM>-k or a value derived therefrom. As an example of the latter, the node light level indication may include a binary flag that indicates whether the local light level currently exceeds a predefined light level threshold, e.g. such that the binary flag is set to value one in case the local light level exceeds the light level threshold and set to value zero in case the local light level fails to exceed the light level threshold.

As described in the foregoing, the lighting control portion <NUM>-k may share at least part of the occupancy information available therein with the one or more external apparatuses <NUM> e.g. via broadcasting the network occupancy status message via the external network. Usage of the external network (instead of the lighting control network) for this purpose ensures that network occupancy status messages do not interfere with delivery of lighting control information (e.g. the status messages) via the lighting control network, thereby facilitating reliable and timely lighting control over the lighting control network. As further described in the foregoing, the external network may be provided using e.g. BLE communication and, consequently, the network occupancy status message may be broadcast in one or more PDUs according to the BLE protocol. In an example, such communication may rely on BLE advertising channel PDUs, which may be also referred to as BLE advertising packets, BLE advertisements or BLE adverts. In this regard, the network occupancy status message may be broadcast in a respective user-definable data field of one or more BLE advertising packets. The employed BLE advertising packets may comprise, for example, connectable undirected advertising (ADV_IND) packets, non-connectable undirected advertising (ADV_NONCONN_IND) packets and/or scannable undirected advertising (ADV_SCAN_IND) packets and the network occupancy status message may be included e.g. in the Complete Local Name field and/or in a Manufacturer Specific Data section of a BLE advertising packet.

The lighting control portion <NUM>-k may compose and broadcast a network occupancy status message according to a predefined schedule, e.g. at predefined time intervals. A suitable schedule may depend, for example, on the roles and purpose of the external apparatuses <NUM>-j. In various examples in this regard, the predefined schedule may define continually broadcasting network occupancy status messages using a time interval selected from a range from a few seconds to a few hours, e.g. <NUM> seconds, <NUM> minutes or <NUM> minutes. In further examples, alternatively or additionally, the lighting control portion <NUM>-k may compose and broadcast a network occupancy status message at predefined times of the day and/or at predefined days of the week, in response to a request from the external apparatus <NUM>-j, and/or in response to having derived a respective predefined number of local occupancy indications and/or remote occupancy indications since broadcasting the most recent previous network occupancy status message.

<FIG> illustrates a block diagram of some components of a lighting system <NUM> according to another example. In this example, the lighting system <NUM> is similar to that illustrated in the example of <FIG> while it further comprises a sensor unit <NUM>-<NUM>, which represents one or more sensor units <NUM>, where an individual sensor unit may be referred to via a reference number <NUM>-m. Each sensor unit <NUM>-m may be arranged to monitor one or more environmental characteristics in a respective location of the one or more spaces. <FIG> illustrates a block diagram of some components of the sensor unit <NUM>-m according to an example. The sensor unit <NUM>-m may comprise a sensor portion <NUM>-m that includes one or more sensors for observing respective environmental characteristics at the location of the sensor unit <NUM>-m and a sensor control apparatus <NUM>-m that comprises a sensor control portion <NUM>-m for controlling at least some aspects of operation of the sensor unit <NUM>-m and a communication portion <NUM>-m for wireless and/or wired communication with other apparatuses. The sensor units <NUM>-m may be communicatively coupled to each other and to the plurality of luminaires <NUM> via the lighting control network and, hence, each sensor unit <NUM>-m may be considered as a respective node of the lighting control network.

The communication portion <NUM>-m may be similar to the communication portion <NUM>-k described in the foregoing and the sensor portion <NUM>-m may be similar to the sensor portion <NUM>-k described in the foregoing, mutatis mutandis. Moreover, operation of the sensor control portion <NUM>-m in terms of its relationship and interoperation with the sensor portion <NUM>-m and the communication portion <NUM>-m is similar to that described in the foregoing for the lighting control portion <NUM>-k, the sensor portion <NUM>-k and the communication portion <NUM>-k, mutatis mutandis. The sensor unit <NUM>-m or an element thereof may have a sensor ID or a device ID assigned thereto, which may comprise e.g. an address, a serial number, a name, etc. assigned to the sensor unit <NUM>-m or to an element thereof. The sensor unit <NUM>-m may be assigned to a luminaire group that includes one or more of the luminaires <NUM>-k and the sensor control portion <NUM>-m may have the knowledge of the luminaire IDs of those luminaires assigned to the same luminaire group and, conversely, the luminaires <NUM>-k of the luminaire group may have the knowledge of the sensor ID of the sensor unit <NUM>-m assigned to the same luminaire group.

As described above for the communication portion <NUM>-k, the communication portion <NUM>-m may enable wired or wireless communication between the sensor control apparatus <NUM>-m and other apparatuses via the lighting control network and/or via the external network. Moreover, along the lines described in the foregoing for the lighting control portion <NUM>-k, the sensor control portion <NUM>-m may operate the communication portion <NUM>-m to transmit, via the lighting control network, status indication messages to other elements coupled to the lighting control network, e.g. to the plurality of luminaires <NUM>. The status indication messages transmitted from the sensor control apparatus <NUM>-m may have structure similar to that described in the foregoing in context of the lighting control apparatus <NUM>-k and they may include one or more sensor indications derived in the sensor control portion <NUM>-m on basis of a sensor signal received from a respective sensor of the sensor portion <NUM>-m, e.g. the current (or the most recent) local occupancy state indication derived on basis of an occupancy sensor signal received from the sensor portion <NUM>-m and/or the current (or the most recent) local light level indication derived on basis of a light sensor signal received from the sensor portion <NUM>-k. Conversely, the lighting control apparatus <NUM>-k may receive, via the lighting control network, status indication messages (and hence status indications) from the sensor unit <NUM>-m and from other sensor units possible included as nodes of the lighting control network.

Consequently, the lighting control logic in the luminaire <NUM>-k assigned to the same luminaire group with the sensor unit <NUM>-m may carry out the lighting control therein further in consideration of respective status indications, e.g. occupancy indications, originating from the sensor unit <NUM>-m. Moreover, (all) luminaires of the lighting system <NUM> may receive the status indications originating from the sensor unit <NUM>-m, whereas the sensor control apparatus <NUM>-m may receive the respective status indications from the plurality of luminaires <NUM> and from other ones of the one or more sensor units <NUM>. Consequently, luminaire <NUM>-k may further base the derivation of the network occupancy status message therein on respective occupancy indications derived from the one or more sensor units <NUM> possibly coupled to the lighting control network, whereas the sensor control portion <NUM>-m of the sensor control apparatus <NUM>-m may compose the network occupancy status message described in the foregoing and broadcast the network occupancy status message via the external network in a manner described in the foregoing for the lighting control apparatus <NUM>-k of the luminaire <NUM>-k, mutatis mutandis.

The examples described in the foregoing assume presence of the sensor portion <NUM>-k and the occupancy sensor therein in the luminaire <NUM>-k. In another example, the luminaire may be provided without the sensor portion <NUM>-k or the sensor portion <NUM>-k in the luminaire <NUM>-k may not include the occupancy sensor. In such a scenario the lighting control rules described above that rely on the local occupancy state derived at the lighting control portion <NUM>-k may be omitted and the lighting control in the lighting control therein may be carried out via the lighting control rules that rely on the respective remote occupancy states derived for one or more other luminaires that are assigned to the same luminaire group with the luminaire <NUM>-k, which occupancy states may be considered as respective occupancy states that are (indirectly) associated with the luminaire <NUM>-k. Alternatively, the lighting control in the lighting control portion <NUM>-k may apply the local-occupancy-state-relying lighting control rules described above by using the group occupancy state derived therein (as described in the foregoing but without consideration of the local occupancy state) as the triggering condition instead of the local occupancy state (which in this example is not available in lighting control portion <NUM>-k due to absence of the occupancy sensor in the luminaire <NUM>-k).

In an example, the external apparatus <NUM>-j may request specific types of occupancy state indications to be included in the network occupancy status message(s) originating from the node of the lighting control network, whereas the node of the lighting network may compose at least one subsequent network occupancy status message accordingly. As an example in this regard, the external apparatus <NUM>-j may request any combination of one or more of the local occupancy state, the group occupancy state, the proximity occupancy state, the network occupancy state, the one or more proximity group occupancy states and the one or more spatial group occupancy states that is implicitly or explicitly described in the foregoing, depending on preferences and/or requirements of the underlying process or system.

As an example, the external apparatus <NUM>-j may transmit, to the luminaire control apparatus <NUM>-k or to the sensor control apparatus <NUM>-k (as the case may be), a message that specifies the types of occupancy states the external apparatus <NUM>-j wishes to receive therefrom and, consequently, the lighting control portion <NUM>-k or the sensor control portion <NUM>-m (as the case may be) may derive the node occupancy state and the at least one regional occupancy state accordingly. In this regard, the external apparatus <NUM>-j may send such a message addressed to the luminaire control apparatus <NUM>-k or to the sensor control apparatus <NUM>-k via the external network, possibly making use of contact information received in the network occupancy status message received therefrom. As a non-limiting example in case the network occupancy status message is received in a BLE advertising packet such as an ADV_IND packet, an ADV_NONCONN_IND packet or an ADV_SCAN_IND packet, the request message may be likewise transmitted in a user-definable field of a BLE advertising packet, e.g. in the Complete Local Name field or the Manufacturer Specific Data section of an ADV_IND packet, an ADV_NONCONN_IND packet or an ADV_SCAN_IND packet.

Upon reception of a network occupancy status message, the external apparatus <NUM>-j may adjust its operation or operation of a system it serves to control in dependence of the node occupancy state and the at least one regional occupancy state received in the network occupancy status message. In particular, the external apparatus <NUM>-j may control the underlying process or system differently in dependence of the indicated node occupancy state and the at least one regional occupancy state:.

As a concrete example in this regard, the external apparatus <NUM>-j may comprise or may be coupled to a thermostat that is arranged to adjust local temperature in accordance with the node occupancy state and the network occupancy state included in the at least one regional occupancy state e.g. such that in case both the node occupancy state and the network occupancy state indicate non-occupancy, a low temperature (e.g. <NUM> degrees Celsius) is applied for energy conservation, in case the node occupancy state indicates non-occupancy but the network occupancy state indicates occupancy, a medium temperature (e.g. <NUM> degrees Celsius) is applied in order to prepare for presence of one or more persons, and in case the node occupancy indicates occupancy, a high temperature (e.g. <NUM> degrees Celsius) is applied for comfort.

In another example, the external apparatus <NUM>-j may control one or more light fixtures that are not coupled to the lighting control network (e.g. spotlights, light fixtures provided for indirect lighting, decoration lights, etc.) in dependence of the node occupancy state and/or the at least one regional occupancy state (e.g. the network occupancy state), for example such that the one or more light fixtures are switched and/or kept on in response to the node occupancy state indicating occupancy or in response to at least one of the node occupancy state and the network occupancy state indicting occupancy while otherwise keeping the one or more light fixtures switched off or at stand-by light level.

In an example, the external apparatus <NUM>-j may estimate proximity of the node of the lighting control network (e.g. the luminaire <NUM>-k or the sensor unit <NUM>-m) from which the network occupancy status message is received via deriving a RSSI for a plurality of messages received therefrom. In this regard, the external apparatus <NUM>-j may compute a RSSI value derived based on the respective RSSIs derived for a plurality of messages received from the respective node (e.g. as an average or as a median of the respective RSSIs derived for messages received therefrom) and the external apparatus <NUM>-j may ignore network occupancy status messages from the respective node in case the RSSI value fails to exceed a predefined RSSI threshold. In this regard, a RSSI value below the RSSI threshold may be considered to represent a node that is too far away from the external apparatus <NUM>-j and/or serve as an indication of a node that is behind a wall or a corresponding.

In an example, the external apparatus <NUM>-j may store, in a memory available therein, history data comprising respective histories of the node occupancy state and the at least one regional occupancy state and to analyze the history data in order to learn one or more patterns in the occupancy data. As an example in this regard, the analysis may aim at learning one or more of the following:.

Consequently, the external apparatus <NUM>-j may make use of an applicable expected time delay in controlling the underlying process or system in a manner that takes into account observed occupancy patterns within the one or more spaces. Non-limiting examples of such an approach include a thermostat adjusting the local temperature, an air-conditioning system adjusting its operation, a home or office appliance or a machine in a factory turning on or off in view of the expected change in occupancy state in vicinity of the node of the lighting control network serving as the source of the network occupancy status messages received at the external apparatus <NUM>-j.

In a further example, in case the network occupancy status messages received at the external apparatus <NUM>-j include the node light level indication described in the foregoing, the external apparatus <NUM>-j may control the underlying process or system further in dependence of the received node light level indications. As an example in this regard, referring back to the example that involves the external apparatus <NUM>-j controlling one or more light fixtures that are not coupled to the lighting control network, switching and/or keeping on the one or more light fixtures may be conditional to the light level indication e.g. such that they are switched and/or kept on only in case the node light level indication suggests light level that the exceed the light level threshold. In another example, the external apparatus <NUM>-j may serve to control window blinds in accordance with the node occupancy status and/or the at least one regional occupancy state and further in view of the node light level indications.

While the examples concerning communication between the nodes of the lighting control network, e.g. between the plurality of luminaires <NUM> and/or the one or more sensor units <NUM> at least implicitly assume wireless communication between the nodes of the lighting control network, along the lines described above, the lighting control network may be provided using wired communication technology instead. As an example in this regard, a communication apparatus of the communication portion <NUM>-k, <NUM>-m that enables wired communication may comprise a network interface (or a bus interface) that is capable of communicating over a wired network or a wired bus using a predefined communication and/or control protocol, such as the Digital Addressable Lighting Interface (DALI) specified in a series of technical standards IEC <NUM>. The choice of the wired communication technique and network topology applied for a specific implementation of the lighting control network and/or the external network may depend e.g. on the required communication range and/or requirements with respect to energy-efficiency of the communication apparatuses.

In such a wired communication scenario the luminaires <NUM>-k and the sensor units <NUM>-m possibly coupled to the lighting control network may acquire knowledge of operational status of other nodes of the network via monitoring the communication carried out via the wired network or bus, in other words receiving control messages and/or status messages transmitted via the wired network or bus. In particular, in addition to the local occupancy state that may be derived in the lighting control portion <NUM>-kof the luminaire <NUM>-k based on the occupancy sensor signal received therein from the sensor portion <NUM>-k provided therein, as an example, the lighting control portion <NUM>-k may be able to acquire occupancy-related information of the following kind via monitoring or receiving messages conveyed via the wired network or bus:.

Moreover, similar observations may be made in the sensor control portion <NUM>-m of the sensor unit <NUM>-m, mutatis mutandis. Consequently, the lighting control portion <NUM>-k or the sensor control portion <NUM>-m may derive the respective remote occupancy states along the lines described in the foregoing and, consequently, make use of the occupancy information available therein to compose and broadcast the network occupancy status message including the node occupancy state and the at least one regional occupancy state.

Some of the operations described in the foregoing with references to the lighting control portion <NUM>-k or the sensor control portion <NUM>-m may be also defined as steps of a method. As an example in this regard, <FIG> depicts a flowchart that illustrates a method <NUM> carried out in the node of the lighting control network (e.g. in the luminaire <NUM>-k or in the sensor unit <NUM>-m), which lighting control network is arranged to communicatively couple, to each other, a plurality of nodes that include the plurality of luminaires <NUM> arranged for illuminating one or more spaces and that may further include the one or more sensor units <NUM>. The respective operations described with references to blocks <NUM> to <NUM> pertaining to the method <NUM> may be varied or complemented in a number of ways, for example as described in the foregoing and/or in the following with references to the luminaire <NUM>-k and/or to the sensor unit <NUM>-m.

The method <NUM> comprises deriving, based on one or more occupancy states that are associated with the node, a node occupancy state that pertains to a location of the node within the one or more spaces, as indicated in block <NUM>. The method <NUM> further comprises receiving, via the lighting control network, one or more status indications originating from one or more other ones of the plurality of nodes of the lighting control network, as indicated in block <NUM>, and deriving, based on the one or more status indications, at least one regional occupancy state that pertains to one or more other locations within the one or more spaces, as indicated in block <NUM>. The method <NUM> further comprises broadcasting, via the external network to the one or more external apparatuses <NUM> that are external to the lighting control network, a network occupancy status message that indicates the node occupancy state and the at least one regional occupancy state, as indicated in block <NUM>.

<FIG> illustrates a block diagram of some components of an apparatus <NUM> that may be employed to implement at least some of the operations described with references to the lighting control apparatus <NUM>-k or the sensor control apparatus <NUM>-m. The apparatus <NUM> comprises a processor <NUM> and a memory <NUM>. The memory <NUM> may store data and computer program code <NUM>. The apparatus <NUM> may further comprise communication means <NUM> for wired or wireless communication with other apparatuses and/or user I/O (input/output) components <NUM> that may be arranged, together with the processor <NUM> and a portion of the computer program code <NUM>, to provide the user interface for receiving input from a user and/or providing output to the user. In particular, the user I/O components may include user input means, such as one or more keys or buttons, a keyboard, a touchscreen or a touchpad, etc. The user I/O components may include output means, such as a display or a touchscreen. The components of the apparatus <NUM> are communicatively coupled to each other via a bus <NUM> that enables transfer of data and control information between the components.

The memory <NUM> and a portion of the computer program code <NUM> stored therein may be further arranged, with the processor <NUM>, to cause the apparatus <NUM> to perform at least some aspects of operation of the lighting control apparatus <NUM>-k or the sensor control apparatus <NUM>-m. Although the processor <NUM> is depicted as a respective single component, it may be implemented as respective one or more separate processing components. Similarly, although the memory <NUM> is depicted as a respective single component, it may be implemented as respective one or more separate components, some or all of which may be integrated/removable and/or may provide permanent / semi-permanent/ dynamic/cached storage.

The computer program code <NUM> may comprise computer-executable instructions that implement at least some aspects of operation of the lighting control apparatus <NUM>-k or the sensor control apparatus <NUM>-m when loaded into the processor <NUM>. As an example, the computer program code <NUM> may include a computer program consisting of one or more sequences of one or more instructions. The processor <NUM> is able to load and execute the computer program by reading the one or more sequences of one or more instructions included therein from the memory <NUM>. The one or more sequences of one or more instructions may be configured to, when executed by the processor <NUM>, cause the apparatus <NUM> to perform at least some aspects of operation of the lighting control apparatus <NUM>-k or the sensor control apparatus <NUM>-m. Hence, the apparatus <NUM> may comprise at least one processor <NUM> and at least one memory <NUM> including the computer program code <NUM> for one or more programs, the at least one memory <NUM> and the computer program code <NUM> configured to, with the at least one processor <NUM>, cause the apparatus <NUM> to perform at least some aspects of operation of the lighting control apparatus <NUM>-k or the sensor control apparatus <NUM>-m.

The computer program code <NUM> may be provided e.g. a computer program product comprising at least one computer-readable non-transitory medium having the computer program code <NUM> stored thereon, which computer program code <NUM>, when executed by the processor <NUM> causes the apparatus <NUM> to perform at least some aspects of operation of the lighting control apparatus <NUM>-k or the sensor control apparatus <NUM>-m. The computer-readable non-transitory medium may comprise a memory device or a record medium such as a CD-ROM, a DVD, a Blu-ray disc or another article of manufacture that tangibly embodies the computer program. As another example, the computer program may be provided as a signal configured to reliably transfer the computer program.

Claim 1:
A control apparatus (<NUM>-k, <NUM>-m) for a node (<NUM>-k, <NUM>-m) of a first network that is arranged to communicatively couple, to each other, a plurality of nodes (<NUM>, <NUM>), wherein said plurality of nodes (<NUM>, <NUM>) comprises a plurality of luminaires (<NUM>) arranged for illuminating one or more spaces, the control apparatus (<NUM>-k, <NUM>-m) comprising:
a communication portion (<NUM>-k, <NUM>-m) for communicating with other apparatuses via the first network and a second network; and
a control portion (<NUM>-k, <NUM>-k) arranged to:
derive, based on one or more occupancy states that are associated with the node (<NUM>-k, <NUM>-m), a node occupancy state that pertains to a location of the node (<NUM>-k, <NUM>-m) within the one or more spaces and indicates one of occupancy or non-occupancy at the location of the node;
receive, via the first network, one or more status indications originating from other ones of the plurality of nodes (<NUM>, <NUM>) of the first network, wherein said status indications are indicative of respective occupancy states at respective locations of said other ones of the plurality of other nodes (<NUM>, <NUM>);
characterized in that the control portion (<NUM>-k, <NUM>-k) is arranged to:
derive, based on said one or more status indications, at least one regional occupancy state such that each regional occupancy state pertains to a respective plurality of other locations within the one or more spaces and indicates one of occupancy or non-occupancy at the respective plurality of other locations; and
broadcast, via the second network to one or more external apparatuses (<NUM>) that are external to the first network, a network occupancy status message that indicates the node occupancy state and the at least one regional occupancy state.