An operating apparatus and method for maintaining network connectivity of network devices based on self-correlated connection information obtained from monitoring maintenance messages

Abstract

The object of the present invention is to provide a device for improving the self-healing capability of a network, wherein the device is suitable for being part of a network (100) such as a ZigBee network. The operating device (110) is suitable for operating a network device (101) and comprises a network information providing unit (111), wherein the network information refers to information about maintenance messages (105, 106, 107) sent and / or received by the network device (101) and / or adjacent network devices (103, 104) to maintain the network, a determining unit (112) for determining self-correlated connection information from the network information, wherein the self-correlated connection information refers to information about the connection of the network device itself to the network; and a control unit (113) for controlling the network device based on the self-correlated connection information.

Description

Technical Field

[0001] The present invention relates to an apparatus, method and computer program for operating a network device, the network device being adapted to be part of a network comprising a plurality of network devices. The present invention further relates to: a network device adapted to be part of a network comprising a plurality of network devices and comprising the apparatus; and a network comprising a plurality of network devices comprising the apparatus. Background Art

[0002] US2014 / 211608 A1 discloses using a router to determine whether the parent device of the router is a coordinator. In this case, the router further determines the link status from the parent device; if the router determines that the link status is not abnormal, the router activates a network recovery process.

[0003] "Z-Stack Developer's Guide" published by Texas Instruments on January 1, 2011 discloses that a ZigBee neighbor from which a link status message has not been received within a certain period of time at a ZigBee router is assumed to be lost.

[0004] In many current applications (e.g., smart home applications), devices (such as lighting fixtures) are adapted to participate in a network with other devices. These networks allow devices to communicate not only with neighboring devices (i.e., devices in the same area as the device), but also with more distant members of the network, with the devices between the communicating members acting as relays for communication. Because these networks are often decentralized, if a network member exits the network (i.e., ceases communication with other network members), most networks are able to reroute communications between their members to compensate for the loss of the member. This ability of a decentralized network to cope with network member failures is referred to as the network's self-healing capability. In the context of self-healing networks, most devices are adapted to monitor whether neighboring devices (i.e., neighboring members) have exited the network and are no longer available for communication. However, in such cases, it is still necessary to notify network users that a device has exited the network and manually reset the exited device so that it can rejoin the network. This can be quite cumbersome for users, and therefore it would be desirable to provide a network device that improves the network's self-healing capability. Summary of the Invention

[0005] The object of the present invention is to provide an apparatus, a network device, a network comprising the network device, a method and a computer program, which allow improving the self-healing capabilities of a network.

[0006] In a first aspect of the present invention, an operating device for operating a network device is proposed, which network device is suitable for being part of a network including multiple network devices, wherein the operating device includes: a) a network information providing unit for providing network information, wherein the network information refers to information about maintenance messages sent and / or received by the network device and / or adjacent network devices of the network device to maintain the network, wherein the adjacent network devices are part of the same network as the network device; b) a determination unit for determining autocorrelation connection information from the network information, wherein the autocorrelation connection information refers to information about the connection of the network device itself to the network; and c) a control unit for controlling the network device based on the autocorrelation connection information.

[0007] Because the determination unit is adapted to determine self-correlated connection information from the network information, where the self-correlated connection information refers to information regarding the network device's own connection to the network, a network device that remains powered on can determine for itself whether it is still connected to the network or is at risk of losing connection. Furthermore, because the control unit is adapted to control the network device based on the self-correlated connection information, the control unit can initiate measures if the self-correlated connection information indicates a problem with the network device's connection to the network. In this case, the control unit can, for example, initiate a network connection reset, increase the power of the network device's network transmission, and so on to prevent disconnection from the network or reconnect the network device to the network. Consequently, the self-healing capabilities of a network including such a network device can be enhanced.

[0008] The operating device is adapted to operate the network device. Specifically, the operating device may be adapted to control the network device, for example, by sending control messages to the network device that affect the functionality provided by the network device. The operating device may be arranged as part of the network device, for example, the hardware or software may be provided in the same housing as the network device. Alternatively, the operating device may be independent of the network device and, for example, provided in its own housing. In this case, the operating device may be directly connected to the network device via a wire or wirelessly connected to the network device for communication with the network device.

[0009] A network device can be any type of device that is suitable for use as part of a network of multiple other network devices having the same or different functionality as the network device. Preferably, the network device is a fixed network device, i.e., a network device that is located at a fixed location during its normal use. The network device is preferably a fixed intelligent network device, i.e., a device that includes network capabilities in addition to at least one or more specific functions. In particular, a fixed intelligent network device does not refer to a general computing device used for general applications or a portable general computing device (such as a smartphone). The network device can, for example, be suitable for use as part of a smart home network application and provide functionality in this context. For example, the network device can be: a sensor device for monitoring temperature, pressure, humidity, etc.; an entertainment device such as a speaker or monitor; or an ambient environment control device such as a temperature control device, a humidity control device, or a lighting control device. Preferably, the network device is a lighting device, comprising at least one lighting unit for providing light to its environment. Furthermore, preferably, the network device is suitable for connection to a lighting network comprising multiple lighting devices, wherein the network may also include additional network devices (such as sensor devices). Furthermore, it is preferred that the network device is adapted to connect to, i.e., be part of, a Zigbee network that communicates using the Zigbee protocol. Additionally or alternatively, the network device may be adapted to connect to, i.e., be part of, a Star Sense wireless network. Generally, the network may be any network with a synchronization (i.e., maintenance) mechanism to maintain the network or determine the state (e.g., health) of the network. The network may be part of an application such as a home control application, an automation application, an industrial application, a security application, a power metering application, or the like.

[0010] The network information providing unit is adapted to provide network information. The network information providing unit may be a storage unit on which the network information is stored and from which the network information can be retrieved. The network information providing unit may also be a retrieval unit, for example, for retrieving the network information from a transmission unit adapted to communicate with the network by sending and receiving data, wherein the network information providing unit is then adapted to determine the network information from the sent and received data, for example, by identifying network-related information from the data. Furthermore, the network information unit may also be a receiving unit and may then, for example, include a transmission unit.

[0011] Network information refers to information about the network to which a network device is connected. A connection to a network can include at least one connection to a network device that is part of the network, but can also include connections to multiple other network devices that are part of the network. Connections between network devices can be wired or wireless. Specifically, a network device can be considered part of a network if it is capable of sending and receiving signals for other members of the network and is further known by at least one other member to be capable of sending and receiving signals from other network devices.

[0012] Network information includes information about maintenance messages sent by a network device and / or its neighboring network devices to maintain the network. Generally, most network communication protocols include the transmission of maintenance messages at regular intervals, which allows each network device that is part of the network to determine which other network devices are within a reasonable communication distance and can be considered to be part of the network. Therefore, these maintenance messages are important for keeping the network of devices active. Network information may include, for example, information about the timing of maintenance messages sent or received, information about the content of maintenance messages, information about the quality of maintenance messages sent or received, or information about any other characteristics related to the sending and receiving of maintenance messages. This information may relate to maintenance messages sent and / or received by the network device itself and / or by neighboring network devices.

[0013] A neighboring network device refers to a network device that is also part of the same network as the network device and is also part of the network neighborhood of the network device. The network neighborhood can be defined, for example, by the communication protocol used, or can be defined by the spatial distance between the network devices. In an example, the neighborhood of a network device can be defined as consisting of all network devices from which the network device receives maintenance messages. In other examples, the neighborhood of a network device can be defined as comprising all network devices in a predefined spatial neighborhood around the network device, or can be defined based on a given structure of the network (such as a given hierarchical order of the network), wherein the neighbors of the network device can then refer only to network devices from which the network device receives maintenance messages and which are further in the same and / or adjacent hierarchical order as the network device.

[0014] The determination unit is adapted to determine self-relevant connection information from the network information. Self-relevant connection information refers to connection information between the network device itself and the network. For example, if the network information includes timing information for sending and receiving maintenance messages from the network device and / or neighboring network devices, the determination unit may be adapted to determine the portion of the timing information related to the network device itself (e.g., the timing of maintenance messages sent or received by the network device itself) as the self-relevant connection information. In another example, if the network information includes information about the device neighbors of neighboring network devices of the network device, the determination unit may determine information related to the network device itself from the neighbor information—e.g., information about whether the network device is considered part of the neighbors of the neighboring network devices—as the self-relevant connection information. Therefore, the self-relevant connection information only relates to information that has a clear relationship with the network device itself. In particular, the self-relevant connection information does not include connection information about other network devices (e.g., neighboring network devices). For example, the self-relevant connection information does not include information about whether another network device is a neighbor or part of a neighboring network device of the network device, or information about whether another network device has sent a maintenance message to the network device.

[0015] The control unit is adapted to control the network device based on the self-correlated connection information. In particular, because the self-correlated connection information provides information regarding the network device's own connection to the network, it is possible to determine whether the network device operated by the operating device is still part of the network or is at risk of being disconnected from the network. For example, if the self-correlated connection information includes information regarding the timing of the network device's own transmission of maintenance messages to its neighboring network devices, the control unit can be adapted to determine that the network device has missed sending maintenance messages for a predetermined period of time and is therefore at risk of being disconnected from the neighboring network devices and, therefore, disconnected from the network. Preferably, the control unit is adapted to control the network device so that, if it is determined that the network device has been disconnected from the network or is at risk of being disconnected from the network, measures are taken to maintain or regain the network device's connection to the network. Such measures may include, for example, resetting the network device, resetting the network device's network connection, powering off or on the network device, increasing the signal strength or bandwidth of the network device's transmissions, rearranging the structure of the network device's network neighborhood, and the like. Thus, the network device, including the operating device, obtains information regarding the status of its own connection to the network and can completely prevent disconnection from the network, thereby improving the overall self-healing capabilities of the network.

[0016] In one embodiment, the self-correlated connection information determined based on the network information includes information indicating the timing of maintenance messages sent by the network device itself. The information indicating the timing of maintenance messages sent by the network device itself may include, for example: information regarding when the last maintenance message was sent, such as the time at which the last maintenance message was sent; information regarding whether the last maintenance message was sent according to a schedule, if the network protocol used by the network device to communicate with the network predefines a schedule for maintenance messages; information regarding the time span between the last maintenance messages sent; and so on. Thus, in this case, the network information includes information regarding whether and how the network device itself has contributed to maintaining the network connection to the network. For example, if it can be determined from the network information that the network device itself has not yet sent a maintenance message as indicated by the maintenance message schedule of the network protocol used in the network, this may indicate that there may be some kind of fault in the network device's software or hardware that allows the network device to recognize that it is part of the network and maintain the network connection. Therefore, in this embodiment, the control unit may be adapted to control the network device so that, for example, based on the network protocol's schedule, if it is determined that the network device has stopped sending maintenance messages or has not been sending maintenance messages on a regular basis, measures are taken to restart or maintain the sending of maintenance messages.

[0017] In a preferred embodiment, the self-correlated connection information determined from the network information includes a time span since the network device itself last sent a maintenance message, wherein the control unit is adapted to compare the determined time span with a predetermined threshold and control the network device based on the result of the comparison. For example, the time span since the network device itself sent the last maintenance message can be determined by comparing the timestamp of the last maintenance message with the current time, or by providing a clock that counts the time between sending a maintenance message and sending the next maintenance message. The predetermined threshold to which the time span is compared can be, for example, a threshold determined based on the maintenance message schedule of the network protocol used by the network device. In this case, the threshold can, for example, be three times the time between scheduled maintenance message transmissions. If the network protocol used is the Zigbee network protocol, and if the Zigbee maintenance status schedule indicates that maintenance messages are sent every 15 to 30 seconds, the threshold can be, for example, 5 minutes. However, the threshold can also be lower or higher. The control unit is then adapted to control the network device based on the result of the comparison. In particular, if the result of the comparison indicates that the determined time span is above the predetermined threshold, the control unit can be adapted to control the network device to take measures to reconnect or maintain connection to the network.

[0018] In one embodiment, the network information includes neighbor information indicating that a network neighbor of the adjacent network device is part of the network neighbor of the network device, wherein the determining unit is adapted to determine the autocorrelation connection information from the neighbor information. As explained above, the network neighbor can be defined, for example, by the communication protocol used, or can be defined by the spatial distance between the network device and the adjacent network device. The neighbor information of the adjacent network device can be provided, for example, as part of a maintenance message sent by each network device, or can be provided to the network device after a request has been received from the network device. In addition, the neighbor information can be sent together with other maintenance information at predetermined intervals as part of the maintenance message. The neighbor information can include identifiers (such as identification numbers) of all network devices that are considered to be part of the neighboring network device's neighborhood. Instead of identification numbers, the neighbor information can also include other identifiers that identify each network device that is considered to be part of the neighboring network device's neighborhood, such as the location of the network device, a name given to the network device by a user, a specific function of the network device in the network, the positioning of the network device in the network's hierarchical structure, etc. In addition, the neighbor information can include more information about the network devices that are considered to be part of the neighborhood than just identifiers. For example, in addition to an identifier, neighbor information may include data indicating the quality of the connection to the network device, information about the connection status of the network device, information about the location of the network device in the structural hierarchy of the network, information about the connection characteristics of the network device (such as the connection bandwidth), the communication protocol used, etc.

[0019] The determination unit is then adapted to determine one or more pieces of self-relevant connection information from the neighbor information, i.e., to extract information related to the network device itself from the neighbor information. For example, the determination unit may be adapted to extract, from the neighbor information, an identifier of the network device, a communication protocol used by the network device, a connection quality between the network device and a neighboring network device, and other information related to the network device itself as self-relevant connection information. The control unit may then be adapted to determine, for example, based on the self-relevant connection information including the self-relevant neighbor information, whether it is necessary to control the network device to take measures to ensure that it is recognized as part of the neighboring network device to maintain connectivity with the network.

[0020] In a preferred embodiment, the determination unit is adapted to determine, from the neighbor information, an indication of whether the network device is known by the neighboring network device as a neighbor of the neighboring network device as self-correlation connection information. The determination unit may be adapted to determine whether the network device is known by the neighboring network device as a neighbor of the neighboring network device, for example, by searching for the identifier of the network device in the neighbor information provided by the neighboring network device. If the neighbor information of the neighboring network device does not include the identifier of the network device itself, the network unit may be adapted to determine that the neighboring network device is not aware that the network device belongs to the neighboring network device. If the determination unit determines that the identifier of the network device itself is provided as part of the neighbor information of the neighboring network device, the determination unit may be adapted to determine that the neighboring network device is aware that the network device belongs to the neighboring network device. The control unit may then be adapted to control the network device based on the self-correlation connection information, which includes information indicating whether the network device itself is known by the neighboring network device as a neighbor of the neighboring network device, to control the network device. Additionally, the determination unit may be adapted to further determine whether the network device is known by another neighboring network device that is a neighbor of the network device based on the neighbor information of the other neighboring network device, in order to verify information received from an earlier neighboring network device. For example, if the network device is not known by the neighboring network device, the determining unit may be adapted to verify whether the network device is known by another neighboring network device in the neighborhood, and based on the result, the control unit may be adapted to control the network device to take measures to inform the neighboring network device of the existence of the network device to maintain the network connection between the network device and the neighboring network device. In addition, if it is determined that the network device is not known by one of the neighboring network devices or a predetermined number of the neighboring network devices, the control unit may also be adapted to take measures to maintain the network connection.

[0021] In one embodiment, the neighbor information includes connection quality data indicating the quality of a network connection between two network devices, wherein the determination unit is adapted to determine autocorrelated connection information from the connection quality data. The connection quality data indicates the quality of the network connection between the two network devices. For example, the connection quality data may refer to a quality value. The quality value may indicate received signal strength (e.g., a received signal strength indicator (RSSI)), communication signal latency, packet transmission delay, communication packet loss or the number of transmission retries, signal-to-noise ratio, passive acknowledgments used during retransmission, etc. The autocorrelated connection information refers to information derived from the connection quality data associated with the network device itself. For example, the autocorrelated connection information determined from the connection quality data may refer to the quality of the connection between the network device and the neighboring network device as perceived by the neighboring network device. The autocorrelated connection information determined from the connection quality data may also refer to the quality of data sent by the network device and received by the neighboring network device. The control unit may then be adapted to control the network device based on the connection quality data. In one embodiment, if the information derived from the connection quality data indicates that the connection quality is below a predetermined threshold, the control unit may be adapted to control the network device to take measures to maintain the connection with the neighboring network device or to reconnect to the neighboring network device.

[0022] In one embodiment, the determining unit is adapted to determine the autocorrelation connection information from the neighbor information of a randomly selected neighboring network device. For example, if the network device receives neighbor information of a plurality of neighboring network devices as part of a maintenance message on a regular basis, the determining unit may be adapted to randomly select a neighboring network device and determine the autocorrelation connection information from the neighbor information of the randomly selected neighboring network device. This embodiment allows ensuring that, over time, the neighbor information from each neighboring network device is used to determine the autocorrelation connection information and thus to check the connection of the network device to each neighboring network device in a timely manner. After the autocorrelation connection information has been determined from the neighbor information of the randomly selected neighboring network device, the determining unit may be adapted to further determine more autocorrelation connection information from the neighbor information of another neighboring network device, in particular another randomly selected neighboring network device.

[0023] In a preferred embodiment, if the determination unit determines from the neighbor information of the randomly selected neighbor network device that the identifier of the network device is known to the neighbor network device, the determination unit can be adapted to further determine connection quality data based on the neighbor information of the randomly selected neighbor network device. For example, the determination unit can be adapted to check whether the quality of the connection between the network device and the neighbor network device is within acceptable limits. If this is the case, the determination unit can be adapted to select the next neighbor information of the next randomly selected neighbor network device to determine these parameters until all neighbor information of the available neighbor network devices has been processed, or until one of the neighbor information indicates a connection failure of the network device to one of the neighbor network devices, wherein the determination unit can then be adapted to provide this information as autocorrelation connection information to the control unit.

[0024] In a preferred embodiment, the neighbor information includes a neighbor table containing identifiers of all network devices that are considered to be part of the neighbors of the network device that sent the neighbor table. Preferably, the neighbor table also includes network-related parameters related to the network devices that are considered to be part of the neighbors of the network device that sent the neighbor table. The additional network-related parameters preferably include connection quality data.

[0025] In one embodiment, if the self-correlated connection information indicates that the network device's connection to the network is failing, the control unit is adapted to control the network device to take measures to reconnect to the network or maintain the connection to the network. If the network device's connection to one or more of its neighboring network devices is failing, the network device's connection to the network can be determined to be a failure. A failure can also include a complete loss of connection to the network or to one or more neighboring network devices. Preferably, a connection failure to the network is indicated when more than one connection to a neighboring network device is lost or indicated to be lost in the near future. A connection failure to a neighboring network device can be indicated, for example, by a combination of one or more of the above-given examples of self-correlated connection information. For example, a connection failure to a neighboring network device can be indicated by a loss of connection quality, a determination that the network device is not part of the neighbor table of one or more neighboring network devices, and / or the network device itself ceasing to send maintenance messages. Based on the structure of the network (e.g., the hierarchical order of the network), the control unit can then be adapted to determine that the network device's connection is failing based on one or more failed connections to the neighboring network devices.

[0026] Preferably, if the self-correlated connection information indicates that the connection of the network device to the network is failing, the control unit is adapted to control the network device to reset itself. Resetting the network device may include, for example, powering off and on the network device, powering off and on parts of the network device, resetting communication with the network (e.g., by sending a reconnect message to the network), performing a channel or network scan, etc. Additionally or alternatively, the control unit may be adapted to take other measures to reconnect to the network or maintain the connection to the network (e.g., by increasing the power used to send communication or maintenance messages), such as determining a more suitable communication channel based on noise on different communication channels, etc.

[0027] Alternatively or additionally, in one embodiment, if the self-correlated connection information indicates that the connection of the network device is failing, the control unit is adapted to control the network device to provide information to a user and / or other network devices regarding the failing connection to the network. Since information regarding the failed network connection of the network device is provided to the user or other network devices, the user or other network devices may be able to react accordingly to the lost network connection of the network device. For example, if resetting the network device still does not allow the network device to reconnect to the network or maintain a stable connection to the network, the control unit may be adapted to provide this information to the user so that the user can intervene, for example, by replacing the network device or repairing the network device. Furthermore, since the network device informs other network devices that the network device's connection to the network (e.g., a connection to at least one neighboring device) is failing, the other network devices may react to this information. For example, the other network devices may begin planning a communication route that does not include the failed network device, may rearrange the structure and / or hierarchical order of the network to compensate for the lost network device, may provide a reconnection signal to the network device, and / or may increase the communication power used to send communication signals to the network device. Therefore, because the failed network device itself is aware of the possible or impending failure, and because the network device communicates the failure directly to other network devices (if possible), information about the failure may be available to the network long before the actual failure of the network device. Therefore, measures to prevent or (if this is not possible) deal with the failed network device are directly available to the network, thereby further improving the self-healing capabilities of the network.

[0028] In a preferred embodiment, the network is a Zigbee network and the network device is adapted to be part of the Zigbee network. Alternatively, the network may be a Star Sense network and the network device may be adapted to be part of the Star Sense network. Furthermore, the network may be based on any other wireless network protocol that follows the network topology (i.e., the network structure) and uses periodic maintenance messages (such as beacon messages) to maintain the network or determine the structure and health of the network.

[0029] In another aspect of the present invention, a network device is provided that is adapted to be part of a network of multiple network devices, wherein the network device includes an operating apparatus for operating the network device according to the above-described embodiments. Preferably, the network device is an intelligent network device, such as part of a home control application, an automation application, an industrial automation application, a security application, a power metering application, etc., wherein the network device is not a general-purpose computer device or a portable computer device (such as a smartphone). In a preferred embodiment, the network device includes lighting capabilities, such as, for example, an intelligent lighting device.

[0030] In another aspect of the present invention, a network is proposed, wherein the network includes a network device according to the above-described embodiment. Preferably, the network is based on the Zigbee network communication protocol. Alternatively, the network may be based on the Star Sense wireless communication protocol or any other wireless network protocol that utilizes knowledge of the mesh topology (i.e., the network structure). In particular, the network includes at least one network device as explained above and a plurality of other network devices, which may also refer to network devices as described above (i.e., including operating devices having the same functions as the network devices or other functions) and may also include additional network devices without operating devices. Preferably, the network includes more than two network devices as described above, and may further include additional network devices with limited network capabilities (e.g., sensor devices that can only send information to the network).

[0031] In another aspect of the present invention, an operating method for operating a network device is proposed, which network device is suitable for being part of a network including multiple network devices, wherein the operating method includes a) providing network information, wherein the network information includes information about maintenance messages sent by the network device and / or neighboring network devices of the network device to maintain the network, wherein the neighboring network devices are part of the same network as the network device, b) determining autocorrelated connection information from the network information, wherein the autocorrelated connection information refers to information about the connection of the network device itself to the network, c) controlling the network device based on the autocorrelated connection information.

[0032] In another aspect of the invention, a computer program for operating a network device is proposed, wherein the computer program comprises program code means for causing the operating device as described above to carry out the steps of the operating method also described above when the computer program is executed by the device.

[0033] It shall be understood that the operating device, the method and the computer program product defined in the independent claims have similar and / or identical preferred embodiments, in particular as defined in the dependent claims.

[0034] It shall be understood that a preferred embodiment of the invention can also be any combination of the dependent claims or the above-described embodiments with the respective independent claim.

[0035] These and other aspects of the invention will be apparent from and elucidated with reference to the embodiments described hereinafter. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In the following drawings:

[0037] Figure 1 Schematically and exemplarily, an embodiment of an operating device for operating a network device as part of a network is shown, Figure 2 schematically and exemplarily shows a network layout including network devices operated by an exemplary operating device, and Figure 3 A flow chart exemplarily illustrating an embodiment of a method for operating a network device is shown. DETAILED DESCRIPTION

[0038] Figure 1 Schematically and exemplarily, embodiments of an operating device for operating a network device that is part of a network are shown. In the following embodiment, the operating device 110 is adapted to operate a network device 101, which network device 101 is, for example, a lighting module for illuminating an environment of the network device. The network device 101 is part of a network 100, which in addition to the network device 101 comprises network devices 102, 103, 104. In this example, the network devices 103, 104 may be regarded as part of a network neighborhood of the network device 101 and may therefore be regarded as neighboring network devices. In this case, the network neighborhood of the network device 101 is defined by the network devices of the network, from which the network device 101 can receive maintenance messages 106, 107 for maintaining the network. In Figure 1 In the example provided in , network device 102 is also part of the network, but is not part of the neighborhood of network device 101 because network device 101 cannot receive maintenance messages sent from network device 101 .

[0039] The operating device 110 for operating the network device 101 includes a network information providing unit 111, a determining unit 112, and a control unit 113. In this embodiment, the operating device 110 is directly connected to the network device 101 and, in particular, is provided in the same housing as the network device 101 (not shown).

[0040] In this case, the network information providing unit 111 is a receiving unit for receiving network information, for example, from a transceiver of the network device 101, which is adapted to send and receive signals to and from the other network devices 102, 103, 104 of the network 100. The network information received from the network information providing unit 111 refers to information about maintenance messages 105, 106, 107 sent and / or received by the network device and / or neighboring network devices 103, 104. The network information received by the network information providing unit 111 may be, for example, the timing of sent and received maintenance messages 105, 106, 107 or neighbor information received from the neighboring network devices 103, 104, wherein the neighbor information preferably takes the form of a neighbor table comprising identifiers of all network devices that are considered to be part of the neighborhood of the network device sending the neighbor table. After having received the network information, for example, after having received the maintenance message 106 including the neighbor table from the adjacent network device 103 , the network information providing unit 111 provides the network information to the determining unit 112 .

[0041] Determining unit 112 is adapted to determine self-correlated connection information from the network information provided by network information providing unit 111. Self-correlated connection information refers to information regarding the connection between network device 101 and network 100. For example, after receiving network information including a neighbor table of neighboring network device 103, determining unit 112 may determine or extract all information in the neighbor table related to network device 101. In the case of a neighbor table, the self-correlated connection information may determine whether the network identifier of network device 101 is present in the neighbor table of neighboring network device 103, indicating that neighboring network device 103 considers network device 101 to be part of its neighborhood. Additionally, if determining unit 112 determines that the network identifier of network device 101 is present in the neighbor table of neighboring network device 103, it may be adapted to further extract connection quality information from the neighbor table indicating the quality of the connection between network device 101 and neighboring network device 103 as perceived by neighboring network device 103.

[0042] In another embodiment, in addition to or as an alternative to the neighbor table, the network information may also include timing information of maintenance messages 105, 106, 107 sent and received by the transceiver of the network device 101. In this example, the determination unit 112 may be adapted to determine the self-correlated connection information based on the timing information of the sent and received maintenance messages 105, 106, 107. Preferably, the determination unit is adapted to determine the time span since the network device 101 itself sent the last maintenance message 105 as the self-correlated connection information or a portion of the self-correlated connection information. If the determined time span is greater than a predetermined threshold—wherein the threshold may be determined, for example, based on the timing schedule of maintenance messages provided by the communication protocol used by the network 100—this may indicate that the network device 101 has lost its connection to the network 100.

[0043] After determining the self-correlated connection information, control unit 113 uses the self-correlated connection information to control network device 101. In particular, if the self-correlated connection information indicates that network device 101 has lost its connection to network 100 or is at risk of losing its connection to network 100, the control unit may be adapted to control network device 101 so that network device 101 takes measures to prevent the loss of network connection or to regain connection to network 100. In particular, control unit 113 may be adapted to control network device 101 so that network device 101 is reset. Resetting may be achieved, for example, by powering off and on network device 101 or various portions of the hardware or software of network device 101. In an example, if the self-correlated network information indicates that a transceiver of network device 101 has not sent a maintenance message 105 to the network as scheduled by the maintenance message schedule of the communication protocol of network 100, the control unit may be adapted to control network device 101 to restart a portion of the software that controls the transceiver of network device 101.

[0044] Alternatively or additionally, if the self-correlated connection information indicates that the network device's connection is failing or has failed, the control unit 113 can be adapted to control the network device to provide information to a user and / or other network devices 102, 103, 104. For example, to notify the user or other network devices, the control unit 113 can be adapted to control the network device 101 to provide a signal, such as an audio and / or optical signal, indicating that there is a problem with the network connection. Alternatively, if an external signal indication is not possible, the network device can update one of its diagnostic properties (e.g., a diagnostic network protocol stored in the network device) to indicate that a failure has occurred, optionally along with additional information about the failure, so that the user can later trace the failure. Furthermore, if at least a portion of the network connection of the device 101 is still available—for example, if it is still possible for the network device 101 to send a message to at least one of the neighboring network devices 103, 104—the control unit 113 can be adapted to control the network device 101 to send a notification to at least one of the neighboring network devices 103, 104 to inform the network 100 of the problem with its network connection. Neighboring network devices 103, 104 may be adapted to detect such a notification from network device 101 and / or may be adapted to detect a change in the lighting signal of network device 101 and / or detect the audio signal of network device 101. Network devices 102, 103, 104 may then be adapted to react accordingly, for example, by rearranging the structure of network 100, such as the hierarchical order of network 100, by searching for a new communication route that does not include network device 101, and / or by attempting to reconnect network device 101 to network 100, for example, by increasing the signal strength of the communication signal of network 100. Additionally or alternatively, a user who perceives the notification of network device 101 may react to the notification of network device 101 and manually attempt to reestablish a connection to network 100, in particular if at least one attempt by network device 101 itself to reestablish a connection to network 100 has failed, which indicates, for example, that some hardware components of network device 101 may be permanently damaged and may have to be replaced.

[0045] Figure 2 A network 200 is shown schematically and exemplarily, to which the operating apparatus described above is applicable. The exemplary network 200 uses the Zigbee communication protocol for communication within the network 200. In this example, the network 200 includes a Zigbee coordinator 210 for coordinating the network and a Figure 2, multiple Zigbee routers 230 are indicated by alphabetical characters in FIG. Furthermore, network 200 includes multiple Zigbee end devices 220 that communicate with one of the Zigbee routers 230. In the embodiment described herein, both the Zigbee coordinator and the Zigbee router are provided with the aforementioned operating means for operating the network devices. To enhance the self-healing capabilities of the Zigbee network 200, the operating means (particularly the determining unit of the operating means) of each of the Zigbee coordinator 210 and the Zigbee router 230 determine the time at which each Zigbee link status message (i.e., a maintenance message in the Zigbee standard) has been transmitted by the corresponding device. Because the Zigbee end devices 220 have the ability to enter sleep mode, in this embodiment, the end devices 220 are not provided with operating means. Furthermore, the operating means of the Zigbee router 230 and the Zigbee coordinator 210 also determine self-correlated connection information from received link status messages of neighboring network devices.

[0046] For example, Zigbee router D may receive link status messages from Zigbee routers A, B, E, H, and the Zigbee coordinator 210. Thus, in this example, Zigbee routers A, B, E, H, and the coordinator 210 may be considered part of the network neighborhood of Zigbee router D. The determination unit of the operating device of Zigbee router D may then be adapted to randomly select one of the link status messages received from Zigbee routers A, B, E, H, and the Zigbee coordinator 210 as a basis for determining self-correlated connection information. For example, the determination unit may determine the connection quality between Zigbee router D and a randomly selected neighboring Zigbee router (e.g., Zigbee router A) from the randomly selected link status message as the self-correlated connection information. If the connection quality perceived by Zigbee router A is below a predetermined threshold, the control unit of Zigbee router D may be adapted to determine that Zigbee router D has gone offline or is in the process of going offline.

[0047] Additionally or alternatively, if the time span since the last link state message sent exceeds a certain threshold (e.g., 5 minutes), the control unit of the Zigbee router D may be adapted to determine that the Zigbee router D has gone offline or is in the process of going offline. In both cases, the control unit may be adapted to control the Zigbee router D to restore itself, for example, by powering off and powering on again to reconnect to the network 200. Thus, a problem with the connection to the network 200 may be determined by the Zigbee router D itself, so that the Zigbee router D itself may take measures to reestablish or maintain the connection to the network 200. This increases the self-healing capability of the Zigbee network 200.

[0048] In the following, reference will be made to Figure 3 The flowchart shown in FIG. 1 describes an embodiment of a method 300 for operating a network device 101 as part of a network 100. The operating method 300 includes a first step 310 of providing network information, wherein the network information includes information about maintenance messages 105, 106, 107 sent by the network device 101 and / or neighboring network devices 103, 104 of the network device 101 to maintain the network 100. In a second step 320, self-related connection information is determined from the network information, wherein the self-related connection information refers to information about the connection of the network device 101 itself to the network 100. Based on the self-related connection information, the method 300 then includes controlling the network device 101 in a step 330. In particular, controlling the network device 101 may include resetting the network device 101, for example, by powering off and on the network device 101.

[0049] For wireless networks comprising multiple network devices, one of the important challenges is to ensure that the network is self-healing and that communications continue without any major problems. To this end, mesh network stack implementations (such as Zigbee stack implementations) ensure that information about all neighboring network devices of a network device is updated at regular intervals. This results in an essentially resilient network. In particular, since information about all neighboring network devices is known to each network device, it is very easy to find alternative routes for communicating from one network device to another. However, the self-healing behavior of the network is mainly based on detecting failures of neighboring network devices, while a network device is not able to detect whether other network devices are unreachable itself. Therefore, the present invention focuses on operating apparatus, methods and computer programs that allow a network device to determine by itself whether there is a problem with its connection to the network.

[0050] For example, the present invention allows network devices that are still powered on but unreachable by other network devices to detect this problem themselves, for example, by periodically checking whether maintenance messages that maintain the network - in particular, maintenance messages used to create and maintain neighbor tables of neighboring network devices - have been sent out according to schedule. In an exemplary embodiment, lighting devices are wirelessly connected in a mesh network. The mesh network uses neighbor tables to maintain the current network, update new network devices into the network, and remove unreachable network devices from the network. In particular, maintenance messages - such as periodic data messages or event messages without any data - are used by network devices to update their neighbor tables. The network devices can then monitor their own maintenance messages, which are sent to maintain the neighbor tables in their neighboring network devices. Alternatively or additionally, the network devices can also check whether the neighbor table of a neighboring device includes an identifier of the network device itself, so that the neighboring network device considers the network device to be part of its neighborhood.

[0051] Generally, any network device capable of wireless communication includes a transceiver for transmitting and receiving messages (e.g., radio messages). In most wireless-based networks, each network device that does not enter sleep mode - in the case of Zigbee networks, particularly Zigbee routers and Zigbee coordinators - keeps sending maintenance messages to keep the network active at all times. Based on these maintenance messages, in most networks, the network devices maintain a neighbor table that identifies all network devices that are part of the network device's network neighborhood. For example, in Zigbee applications, link status messages are sent at regular intervals to all network devices in the nearest neighborhood, i.e., the hub count is 1. In the case of Zigbee applications, the link status message contains the network addresses (i.e., network identifiers) of all neighboring network devices of the network device sending the link status message, as well as input / output link quality information (i.e., connection quality data). More information on the details of the link status messages in the ZigBee communication protocol can be found, for example, in Section 3.4.8 of the December 16, 2014 version of the Zigbee specification.

[0052] In the case of a Zigbee network, a link status message is sent periodically (such as every few seconds, for example, in particular every 15 to 30 seconds) to inform other network devices of the network of the presence of the network device. In an embodiment of the proposed invention, for example, a wireless message stack processed by an operating device records the time of transmission of the last periodic maintenance message (for example, a link status message in the case of Zigbee).

[0053] Furthermore, in an embodiment of the proposed invention, each network device—in particular, an operating device that is part of the network device—monitors its own entry (i.e., network identifier) in a neighbor table in received maintenance messages from neighboring network devices on a random basis to ensure that the network device is not constantly monitoring maintenance messages from the same neighboring network device. Specifically, the network device (in particular, the operating device of the network device) can be configured to monitor periodic maintenance messages and not only add or remove neighboring network devices, but also look for its own entry (i.e., network identifier) in the maintenance message. If the entry is present, the link quality indicator (i.e., connection quality data) can be considered to determine the degree to which the network device is considered reachable by neighboring network devices. If the link quality indicator of the network device, as determined by multiple neighboring network devices, is above a threshold—for example, above 180 out of 255 in the case of Zigbee—the network device can be considered healthy. If the link quality indicator of the network device shows degradation over a period of time as seen by at least one neighboring device, the network device can be aware that it is in the process of going offline (i.e., failing).

[0054] The same general principles can be implemented in Zigbee stacks or Bluetooth Low Energy (BLE) stacks to improve the self-healing capabilities of the network. Furthermore, the stack used in the Star Sense wireless solution can also be adapted based on the principles described above. In the case of the StarSense RF stack, a maintenance message (i.e., beacon) is sent every 90 seconds to enable the maintenance of the neighbor table (i.e., network table) in the network.

[0055] Although the present invention is mainly explained based on the Zigbee network in the above embodiment, the network may also use other network communication protocols, such as, for example, the Star Sense communication protocol, the BLE mesh communication protocol, the 6LoWPAN communication protocol, etc. In addition, although in the above embodiment, the network device includes a lighting unit to implement a lighting function, in other embodiments, the network device may provide other functions, such as, for example, a sensor function, an entertainment function, an environment manipulation function, etc.

[0056] Other variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed invention, from a study of the drawings, the disclosure, and the appended claims.

[0057] In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite article "a" or "an" does not exclude a plurality.

[0058] A single unit or device may fulfill the functions of several items recited in the claims. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.

[0059] The processes performed by one or more units or devices (e.g., providing network information, determining self-related connection information, and controlling network devices) may be performed by any other number of units or devices. For example, the processes may be performed by a single device. The processes may be implemented as program code means of a computer program and / or as dedicated hardware.

[0060] The computer program may be stored / distributed on a suitable medium, such as an optical storage medium or solid-state medium, provided together with or as part of other hardware; but may also be distributed in other forms, such as via the Internet or other wired or wireless communication systems.

[0061] Any reference signs in the claims should not be construed as limiting the scope.

[0062] The present invention relates to providing an apparatus for improving the self-healing capability of a network, wherein the apparatus is suitable for being part of a network (such as a Zigbee network). The operating apparatus is suitable for operating a network device and comprises: a network information providing unit, wherein the network information refers to information about maintenance messages sent and / or received by the network device and / or adjacent network devices to maintain the network; a determining unit for determining self-correlated connection information from the network information, wherein the self-correlated connection information refers to information about the connection between the network device itself and the network; and a control unit for controlling the network device based on the self-correlated connection information.

Claims

1. An operating apparatus for operating a network device (101), the network device (101) being adapted to be part of a network (100) comprising a plurality of network devices, wherein the operating apparatus (110) comprises: A network information providing unit (111) is configured to provide network information, wherein the network information refers to information about maintenance messages sent and / or received by the network device (101) and / or a neighboring network device of the network device (101) to maintain the network (100), wherein the neighboring network device is part of the network (100), a determining unit (112) configured to determine autocorrelation connection information from the network information, wherein the autocorrelation connection information refers to information about the connection between the network device (101) itself and the network (100), a control unit (113) for controlling the network device (101) based on the autocorrelation connection information, wherein the network information comprises neighbor information indicating a network neighbor of a neighboring network device, the neighboring network device being part of a network neighbor of the network device (101), and wherein the determining unit (112) is adapted to determine the autocorrelation connection information based on the neighbor information, wherein the determining unit (112) is adapted to determine, from the neighbor information, an indication of whether the network device (101) is known by the neighboring network device as a neighbor of the neighboring network device, as the self-correlated connection information, and wherein if the self-correlated connection information indicates that the connection of the network device (101) to the network (100) is failing, the control unit (113) is adapted to control the network device (101) to take measures to reconnect to the network (100).

2. The operating apparatus according to claim 1, wherein the self-correlation connection information determined from the network information includes information indicating the timing of maintenance messages sent by the network device (101) itself.

3. An operating device according to claim 1, wherein the self-correlated connection information determined from the network information includes a time span since the network device (101) itself has sent a last maintenance message, wherein the control unit (113) is adapted to compare the determined time span with a predetermined threshold value and control the network device (101) based on the result of the comparison.

4. An operating device according to claim 2, wherein the self-correlated connection information determined from the network information includes a time span since the network device (101) itself has sent a last maintenance message, wherein the control unit (113) is adapted to compare the determined time span with a predetermined threshold value and to control the network device (101) based on the result of the comparison.

5. The operating device according to claim 1, wherein the neighbor information comprises connection quality data indicating a quality of a network connection between two network devices, wherein the determining unit (112) is adapted to determine the autocorrelation connection information from the connection quality data.

6. The operating device according to any one of claims 1 to 5, wherein the determining unit (112) is adapted to determine the autocorrelation connection information from the neighbor information of randomly selected adjacent network devices.

7. The operating apparatus according to any one of claims 1 to 5, wherein the neighbor information comprises a neighbor table containing identifiers of all network devices that are considered to be part of the neighbors of the network device that sent the neighbor table.

8. An operating device according to any one of claims 1 to 5, wherein if the self-correlation connection information indicates that the connection of the network device (101) is failing, the control unit (113) is suitable for controlling the network device (101) to provide information that the connection with the network (100) is failing to a user and / or other network devices.

9. The operating apparatus according to any one of claims 1 to 5, wherein the network (100) is a ZigBee network, and the network device (101) is adapted to be part of the ZigBee network.

10. A network device adapted to be part of a network of a plurality of network devices and comprising an operating device (110) for operating the network device (101) according to claim 1.

11. A network comprising at least one network device (101) according to claim 10.

12. A method for operating a network device (101), the network device being adapted to be part of a network (100) comprising a plurality of network devices, wherein the method comprises: providing (310) network information, wherein the network information comprises information about maintenance messages sent by the network device (101) and / or a neighboring network device of the network device (101) to maintain the network (100), wherein the neighboring network device is part of the network (100), determining (320) self-correlated connection information from the network information, wherein the self-correlated connection information refers to information about the connection of the network device (101) itself to the network (100), controlling (330) the network device (101) based on the autocorrelation connection information, wherein the network information comprises neighbor information indicating a network neighbor of a neighboring network device, the neighboring network device being part of a network neighbor of the network device (101), and wherein the determining (320) comprises determining the autocorrelation connection information based on the neighbor information, wherein the determining (320) comprises determining, from the neighbor information, an indication of whether the network device (101) is known by the neighboring network device as belonging to a neighbor of the neighboring network device, as the self-correlated connection information, and wherein controlling the network device (101) comprises controlling the network device (101) to take steps to reconnect to the network (100) if the self-correlated connection information indicates that the connection of the network device (101) to the network (100) is failing.

13. A computer program product comprising a computer program for operating a network device, wherein when the computer program is executed by the operating apparatus according to claim 1, the computer program causes the operating apparatus to carry out the steps of the operating method according to claim 12.

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