Receiver-centric communication using combined network technologies to enhance reliability

Abstract

This invention relates to a receiver-centric transmission system for IoT systems, such as lighting networks, featuring a combined protocol radio chip that allows two or more transmission protocols of different network technologies to share a single radio front end while preventing unacceptable performance degradation in one or two protocol modes. The receiver-centric approach allows for the implementation of two networks with acceptable performance on a single radio chip at each node, instead of requiring two radio chips per node.

Description

Technical Field

[0001] This invention relates to the field of communication of network devices in multi-hop mesh networks such as, but not limited to, Zigbee networks, for use in a variety of different Internet of Things (IoT) applications in homes, offices, retail, hotels, and industries. Background Technology

[0002] Zigbee networking represents another type of low-power / low-cost wireless network that allows multi-hop communication between devices in a mesh topology. Zigbee devices offer reduced power consumption and cost, along with mesh networking capabilities, making them suitable for use in large-scale deployments. Examples of Zigbee mesh network applications include home automation, building automation, retail services, smart energy, and wireless indoor lighting systems.

[0003] More specifically, Zigbee is a high-level communication protocol based on the IEEE 802.15.4 specification, used to create personal area networks with small, low-power digital radios. A key benefit of Zigbee technology is its vertical integration—the availability of a complete standardized protocol stack from the lower-layer IEEE 802.15.4 specification to the network and application layers; as opposed to other wireless networking technologies such as Thread, Bluetooth, or Wi-Fi. Zigbee networks are widely used in various applications, including homes, retail, and industrial / office settings. Applications include wireless light switches, lights, thermostats, various sensors, electricity meters with in-home displays, traffic management systems, and other consumer and industrial equipment requiring short-range, low-rate wireless data transmission. Its low power consumption, depending on power output and environmental characteristics, limits transmission distance to 10-100m within line of sight. Zigbee devices can transmit data over longer distances via a mesh network of intermediate devices.

[0004] The so-called Zigbee Optical Link (ZLL) standard is a low-power mesh network standard used by connected lighting systems. The ZLL stack consists of four layers: Physical (PHY), Media Access Control (MAC), Network (NWK), and Application (APL). Two lower layers, PHY and MAC, are defined in the IEEE 802.15.4-2003 specification. During initial setup, ZLL devices perform a commissioning procedure to obtain the network key. Commissioning is the process of setting up a new ZLL network or adding a new ZLL device to an existing network.

[0005] Recent advances in integrated circuit design have made it possible to combine Bluetooth Low Energy (BLE) and Zigbee technologies on a single radio chip, allowing low-power / low-cost devices to operate simultaneously as part of both BLE and Zigbee networks, utilizing a single wireless radio module. This can be achieved by rapidly switching BLE and Zigbee device operation over time, allowing the device to remain connected and operate in both networks simultaneously. The possibility of allowing constrained devices to operate on both BLE and Zigbee networks (or any other combination of single-hop and multi-hop networks) opens up new solutions to overcome the limitations of these existing technologies. BLE is a low-power / low-cost wireless networking technology that enables single-hop communication in a star topology between a master node and a limited number of power-constrained slave nodes. BLE provides energy-efficient connectivity between power-constrained slave devices and less power-constrained master devices. An example of a BLE network could consist of a mobile phone device acting as the master, providing internet connectivity to an ecosystem of resource-constrained devices such as sensors, wearables, and building automation equipment.

[0006] The availability of so-called combined radio chips (such as Zigbee / BLE, BLE / Wi-Fi, or other combinations of multi-hop and single-hop protocols), where two wireless protocol stacks share a single radio front end in the time domain, enables new features of IoT systems such as IoT lighting systems. These new features include direct control of node functions (e.g., wireless lighting) via single-hop (e.g., BLE) connections from mobile devices, locating mobile phones via single-hop (e.g., BLE) signals transmitted from the wireless IoT system, and tracking assets via mobile single-hop (e.g., BLE) tags whose signals are received by the IoT system (e.g., overhead wireless lighting networks).

[0007] WO2018 / 228883A1 discloses examples of applications utilizing radio chips that can combine BLE and Zigbee. WO2018 / 228883A1 discloses a system and method for extending the coverage of a wireless single-hop network (e.g., a BLE network) by relaying messages of a wireless single-hop network over a wireless multi-hop network (e.g., a Zigbee mesh network). This benefits from the combined single-hop / multi-hop (e.g., BLE / Zigbee) capability of a wireless combining device that can seamlessly bridge between two wireless networks.

[0008] While the combined radio chip offers clear benefits for IoT systems, system designs must also address a common constraint when balancing the performance of classic lighting control with that of the newly added features. This common constraint stems from the fact that although two radio protocol stacks exist, only one radio front-end must be shared between the two stacks. Poor management could lead to a significant performance degradation of at least one radio protocol.

[0009] In an exemplary case of Zigbee broadcasting for lighting control in a Zigbee-based lighting system, a BLE / Zigbee radio scheduler is inserted between the MAC and PHY protocol layers. This scheduler is used to schedule the shared radio hardware for both Zigbee and BLE stacks, typically in duty cycle mode. However, if the duty cycle for BLE operation is denoted as 'd', the radio will operate in BLE mode for 'd' of the total time, while Zigbee mode can only be used for a portion of the total time (1-d). At the receiver, if a Zigbee packet arrives during the receiver's BLE mode, it will be unconditionally lost. Therefore, an additional loss due to the combined operating duty cycle is now present in the system. Clearly, the larger 'd' is, the more degraded the Zigbee reception becomes.

[0010] If retransmission is possible, the loss can be corrected. In fact, in Zigbee broadcasts, neighboring router nodes will help retransmit messages. Unfortunately, the packet loss rate does not improve in the same way when the duty cycle is different. While subsequent transmissions can quickly correct for small duty cycles, the improvement is much slower when the duty cycle is large (and therefore the packet loss rate per transmission is large), because the correction is proportional to (1-d) for each transmission.

[0011] For some applications, such as asset tracking, all or most nodes need to listen for incoming single-hop broadcast signals (e.g., BLE signals) from single-hop labels (e.g., BLE labels). This means that for those nodes, a large d is expected, i.e., a large duty cycle for single-hop (e.g., BLE) modes. Conversely, this also means that multi-hop (e.g., Zigbee) broadcast performance will degrade further as retransmissions become less efficient. Exemplary measurements of combined BLE / Zigbee modes show that if the BLE duty cycle is 10%, which means 10% packet loss in Zigbee transmissions, only one further transmission will be needed to reduce the final packet loss rate to 1%, and the total number of attempts is 1.1 if a second attempt is made only for those that failed on the first attempt (in the case of a 10% failure rate on the first attempt). However, if the BLE duty cycle is 70%, and the resulting Zigbee packet loss is also 70%, it will take a total of 14 attempts and 3.31 of the total load to achieve the same final loss rate of 1.0%.

[0012] Therefore, while combining radio chips brings the benefits of new features, performance must be balanced between classic node control (e.g., lighting control) and the newly added features. As can be seen from the exemplary measurements above, the addition of BLE mode will inevitably introduce performance degradation to Zigbee transmissions. And while measures such as retransmission exist to help correct this degradation, they come at a cost in terms of increased traffic load or increased latency, which grows non-linearly with the BLE mode duty cycle. Summary of the Invention

[0013] The purpose of this invention is to provide enhanced reliability for combined radio chips with combined network technology that shares a single radio front end.

[0014] This objective is achieved through the network nodes, lighting systems, methods, and computer program products provided in this application.

[0015] According to a first aspect, a network node for use in a network is provided, the network node being configured to transmit or receive data on a time-sharing basis according to a predetermined duty cycle in a first communication mode using a first network technology or a second communication mode using a second network technology, the network node including means for controlling transmissions of the network node in the network, wherein the means is characterized in that it includes: a determining unit for determining a preferred communication mode for a target node of transmission, the preferred mode being the communication mode of the target node most frequently used in the first and second communication modes; and a selecting unit for selecting one of the first and second communication modes based on the determined preferred communication mode of the target node for transmission to the target node, wherein the preferred communication mode is based on information about the target node, which is retrieved directly from the target node, indirectly from another node or gateway, or may be generated by pre-configured rules.

[0016] Optionally, the preferred communication mode is based on information about the target node, which can be retrieved directly from the target node via an out-of-band mechanism or generated by pre-configured rules.

[0017] A preferred (e.g., most commonly used) communication mode of the network technology for the intended destination or next-hop node is determined. Based on the determined preferred communication mode of the destination node, one of the first and second communication modes of the first and second network technologies (e.g., a combination of BLE and Zigbee or other network technologies) of the transmitting network node is selected for transmission to the destination node via its single radio chip. Therefore, a receiver-centric transmission method is proposed to prevent unacceptable performance degradation in one or both communication modes. The receiver-centric approach allows for the implementation of two networks with acceptable performance on a single radio chip at each node, instead of requiring two radio chips per node. Nodes in the network can have the capability to transmit and receive using two network technologies in a time-division multiplexing manner with specific duty cycles, and the network technologies may be incompatible with each other. Time sharing of the network technologies may be uneven, making the preferred communication mode of the destination node potentially the communication mode with the highest broadcast time percentage.

[0018] Note that the proposed solution is not limited to two communication modes, but can be extended to three or more communication modes.

[0019] According to the first option, the network node can be configured as a terminal device of the second technology, operating as a device of the first network technology with a larger duty cycle in the first communication mode. Therefore, increased reception reliability of messages or suggestions in the first communication mode can be achieved, while still allowing communication in the second communication mode.

[0020] Based on a second option that can be combined with the first option, if (e.g., by the determining unit) it is determined that the network's gateway device is used as the destination node for transmission, then (e.g., by the selecting unit) a second communication mode can be selected for transmission to the parent node or the next-hop node. Since the gateway device is mostly set to the second communication mode, reliable reception of the transmission can be achieved.

[0021] According to a third option, which can be combined with the first or second option, if it is determined (e.g., by the determining unit) that all network nodes are the destination nodes for the transmission, then the second communication mode can be selected (e.g., by the selecting unit) for broadcast transmission to the parent node. Therefore, assuming that all nodes are at least temporarily able to receive the second communication mode, it can be ensured that the broadcast message will be reliably received by all nodes.

[0022] According to the fourth option, which can be combined with any of the first to third options, a network node can be configured as a terminal device or router device of a first network technology operating with a larger duty cycle of a first communication mode, or as a terminal device or router device of a second network technology operating with a larger duty cycle of a second communication mode. Therefore, flexible use of both communication modes is possible, as the network node does not need to always use a specific communication mode.

[0023] According to a fifth option, which can be combined with any of the first to fourth options, the preferred communication mode of the destination or next-hop node can be determined via an out-of-band mechanism (e.g., through communication with the destination node outside the transmission bands of the first and second network technologies) (e.g., by a determining unit), wherein the selecting unit can be configured to select the determined preferred communication mode for transmission to the destination or next-hop node. This measure ensures that the preferred communication mode of the target node can be reliably determined.

[0024] According to a sixth option, which can be combined with any of the first to fifth options, the preferred communication mode of the destination or next-hop node can be determined (e.g., by a determining unit) based on the application operating on the network node for transmission, wherein the determined preferred communication mode is selected (e.g., by a selecting unit) for transmission to the target node. Therefore, by directly deriving the preferred communication mode of the target node from the application running on the transmitting network node during transmission to the destination or next-hop node, the reliability of the transmission can be enhanced.

[0025] According to the seventh option, which can be combined with any of the first through sixth options, if the network node is operating on an application that broadcasts data, the first communication mode can be determined (e.g., by the determining unit). Assuming all nodes are listening to both communication modes, this measure ensures that the broadcast transmission is reliably received by all network nodes.

[0026] According to the eighth option, which can be combined with any of the first through seventh options, if the network node is operating on an application of unicast or many-to-one transmission, a second communication mode can be determined (e.g., by the determining unit). Assuming that each node will adapt its communication mode to the next-hop receiving node, this measure ensures that the unicast or many-to-one transmission is reliably received by the destination or next-hop node.

[0027] According to the ninth option, which can be combined with any of the first through eighth options, if the network node is operating in a broadcast transmission application, then (e.g., by the determining unit) both the first and second communication modes are determined. Thus, the transmitting node ensures that all network nodes will receive the broadcast transmission without relying on other router devices.

[0028] According to a tenth option, which can be combined with any of the first to ninth options, the plurality of network nodes may include: a first network node configured as a terminal device of the second network technology and operating as a device of the first network technology with a larger duty cycle of the first communication mode; and a second network node configured as a router device of the second network technology and operating with a larger duty cycle of the second communication mode, wherein the second network node can be configured to forward information of received broadcast messages of the second communication mode in advertising messages of the first communication mode. This ensures that the information of the broadcast messages reaches all network nodes reliably.

[0029] According to the eleventh option, which can be combined with any of the first to tenth options, the plurality of network nodes may include a first network node configured as a router device of a first network technology and operating with a larger duty cycle of a first communication mode, and a second network node configured as a terminal device or router device of a second network technology and operating with a larger duty cycle of a second communication mode. The first network node may be configured to forward received broadcast messages of the first communication mode in both the first and second communication modes, and / or the second network node may be configured to convert received unicast messages of the second communication mode into messages of the first communication protocol, or, if the next-hop node is the first network node, tunnel received unicast messages into messages of the first communication protocol. This ensures that broadcast, unicast, and many-to-one transmitted information reliably reaches the desired network node.

[0030] Note that the above devices may be implemented based on discrete hardware circuits, integrated chips, or chip modules with discrete hardware components, or based on signal processing devices or chips controlled by software routines or programs stored in memory, written on computer-readable media, or downloaded from a network (such as the Internet).

[0031] Furthermore, it should be noted that radio chips or chip modules have evolved in recent years, with functionality shifting towards software. Therefore, high-frequency functions (especially at the Physical Protocol Layer (PHY layer), such as actual channel modulation) can still be implemented in hardware, while lower-frequency functions are implemented in software (especially at the Media Access Control Layer (MAC layer) and above). Consequently, certain hardware components of the PHY layer can be reused for different radio functions. Thus, the first and second communication units—which can be described as separate units in the embodiments below—can actually be implemented, for example, in a single hardware component based on different software routines. Therefore, these two communication units can be implemented as a so-called software-defined radio, where radio functions at and above the MAC layer can be mapped to the software layer, and where PHY layer functions, such as channel modulation, can still be implemented primarily in hardware. However, even when using a software-defined radio device capable of operating in multiple modes, the device can still be configured to operate as a communication unit for a first network technology when used in a first communication mode (e.g., BLE radio), and it can still be configured to operate as a communication unit for a second network technology when used in a second communication mode (e.g., Zigbee radio).

[0032] It should be understood that the network nodes, lighting systems, methods, and computer program products provided in this application may have similar and / or identical preferred embodiments, particularly as described in the options above.

[0033] It should be understood that the preferred embodiments of the present invention may also be any combination of the dependent claims or the above embodiments with the corresponding independent claims.

[0034] These and other aspects of the invention will become clear and elucidated with reference to the embodiments described below. Attached Figure Description

[0035] In the following figures:

[0036] Figure 1 A schematic architecture of a lighting system-based asset tracking system according to various embodiments is illustrated.

[0037] Figure 2 An exemplary network architecture with combined network nodes is illustrated schematically according to various embodiments;

[0038] Figure 3 A block diagram schematically illustrates a combined network node according to various embodiments; and

[0039] Figure 4 A flowchart illustrating a receiver-centric transmission process according to various embodiments is shown. Detailed Implementation

[0040] Embodiments of the invention will now be described based on Zigbee networks as an example of a first network technology (e.g., multi-hop technology) and Bluetooth Low Energy (BLE) connections or networks as an example of a second network technology (e.g., point-to-point connections based on single-hop technology).

[0041] More specifically, based on various embodiments, different reliability enhancement methods are presented below for IoT networks that use combined radio chips to provide more than one function.

[0042] Generally, network nodes in a network can transmit or receive on two network technologies, or both, but cannot transmit or receive simultaneously due to their single radio hardware (i.e., a single RF front-end unit). Network nodes operate on different network technologies with very different duty cycles. As a result, there are network nodes that primarily operate on the first network technology (e.g., eavesdropping), while other network nodes primarily operate on the second network technology (e.g., eavesdropping).

[0043] In the following description, a lighting IoT network is illustrated in an exemplary embodiment, wherein each node has a combined radio chip for both classic lighting control functions and asset tracking using BLE tags.

[0044] Figure 1 The architecture of a lighting system-based asset tracking system according to various embodiments is illustrated schematically.

[0045] Generally speaking, asset tracking can refer to tracking physical assets by scanning barcode tags attached to assets or by using tags with transmitters such as GPS, BLE, infrared (IR), or radio frequency identification (RFID), which broadcast their location. These technologies can also be used indoors to track tagged people or objects.

[0046] exist Figure 1 In this process, BLE tag 40 periodically transmits BLE beacon signal B, which is received by nodes of lighting network 100 equipped with a combined radio chip. Measurements M of the BLE beacon B are performed, and the results are transmitted via the combined radio chip through the lighting network using the Zigbee protocol to positioning engine 10. Positioning engine 10 queries lighting location database 22 to obtain the identifier (ID) and reference location (R) of the combined radio chip or corresponding luminaire from which measurements have been received. Based on this, positioning engine 10 determines location updates P and forwards them to location-based services (e.g., dashboards for information display) provided at user terminal equipment 30. The tracked assets can then be displayed on a map MP retrieved from map database 24.

[0047] The lighting network 100 consists of nodes equipped with combined BLE / Zigbee radio chips. To enable both lighting control and asset tracking, a fixed set of nodes can be designated as Zigbee-dedicated routers operating only or primarily in Zigbee mode, while the remaining nodes can operate in both Zigbee and BLE modes. The Zigbee-dedicated router set can then maintain Zigbee operation. These non-router nodes can be primarily configured in BLE mode, but can be configured in Zigbee mode when they have something to send or receive. The reason for the non-router nodes operating primarily in BLE mode is likely to facilitate the reception of BLE beacon signals from BLE tags 40. The longer the non-router nodes can operate in BLE mode, the better the performance of receiving BLE signals from BLE tags 40, and therefore the better the tag battery life.

[0048] Figure 2 The illustration shows an exemplary network configuration with an exemplary number of 100 nodes, where the bright nodes (node ​​numbers 5, 12, 19, 34, 37, 50, 51, 64, 67, 82, 89, and 96) are Zigbee-dedicated router nodes, and the dark non-router nodes operate in a mixed Zigbee / BLE mode. Non-router nodes can transmit without much problem as long as there are enough Zigbee-dedicated router nodes nearby. However, if a non-router node operates primarily in BLE mode, it will have reception problems and will therefore lose most of the Zigbee packets sent to it by the Zigbee-dedicated router nodes. Transmissions from surrounding router nodes can help mitigate packet loss, although this is only possible if sufficient retransmissions are available.

[0049] According to various embodiments, a hybrid operating mode (i.e., network technology) is provided for all network nodes, but an optimal sending and receiving strategy is employed for each operating mode (i.e., network technology) present in the network. This strategy follows a receiver-centric principle, meaning that when a node sends a message to one or more other nodes, it sends it in the mode in which the receiving node has operated the longest (i.e., on that network technology). This improves the reception probability, especially when the duty cycle between the two modes is uneven.

[0050] refer to Figure 2For example, a bright node is a Zigbee router that operates only in Zigbee mode or primarily in Zigbee mode, while a dark node is a Zigbee non-router node that operates primarily in BLE mode. Zigbee router nodes need to be in Zigbee mode most of the time because they need to continuously listen to the Zigbee network to maintain normal operation. Similarly, non-Zigbee router nodes need to be in BLE mode most of the time to continuously listen for incoming BLE signals from tag 40. Therefore, it is recommended to send any packets to them in the mode they operate in most frequently. Conversely, if packets are sent to them in the mode they operate in least frequently, this will result in significant packet loss, as discussed previously.

[0051] Figure 3 A network node with a combined radio chip (such as...) is schematically shown. Figure 2 A diagram showing the bright and dark nodes.

[0052] The first protocol unit 32 (P1) provides protocol functionality for a first network technology (e.g., BLE) to a single shared RF front-end unit 39 for transmitting and receiving wireless signals via transmit and receive antennas. Additionally, the second protocol unit 34 (P2) provides protocol functionality for a second network technology (e.g., Zigbee) to the shared RF front-end 39 for transmitting and receiving wireless signals via transmit and receive antennas. A switching unit (SW) 36 switches between the first protocol unit 32 and the second protocol unit 34 to provide the RF front-end 39 with the correct message / signaling for the selected network technology based on control signals received from the control unit (CTRL) 38. The control unit 38 can also transmit and receive information directly via the RF front-end 39, for example, via out-of-band signaling.

[0053] In simple cases, the duty cycle of two network technologies can be configured when a network node starts operating or joins the network through debugging.

[0054] when Figure 3 When a network node is transmitting (i.e., as a source node) or further relaying (i.e., as a router or relay node), the control unit 38 can determine (i.e., select) the network technology used for transmission to the destination / target node based on retrieved information about (one or more) destination / target nodes.

[0055] As explained in the following example embodiments, the decision regarding which network technology to use for transmission can be based on some (e.g., pre-configured) rules and inputs regarding the application mode (unicast, broadcast, etc.), the network address used, etc. The retrieved information can therefore be associated with at least one of the following: the transmission application (e.g., unicast, broadcast, multicast, etc.), the preferred network technology primarily operated by the destination / target node, the destination address format or value, and the application message type. For example, in the case of a unicast application, control unit 38 can select a single network technology, i.e., the network technology primarily operated by the destination / target node, for forwarding. Alternatively, in the case of broadcast and / or multicast applications, control unit 38 can select to send over only one or both network technologies to reach network nodes primarily operating on either of the two network technologies. In the first configuration, Figure 2 The dark nodes are Zigbee end devices and operate as BLE devices, but with a large BLE duty cycle. There is no network between the dark nodes, but they can receive tag beacon signals on, for example, three BLE advertising channels. Figure 2 The bright nodes are Zigbee routers.

[0056] The retrieved information may originate, for example, from a central source or from the target node itself; in one embodiment, a central source, such as a gateway, may register their respective preferred communication modes for each node. This mode can be set during commissioning and / or dynamically. In the latter case, it may be easier to retrieve the preferred communication mode directly or indirectly from the target node itself, which is common within mesh networks, where nodes may, for example, cache the preferred communication modes of their frequent communication partners and poll their frequent communication partners from time to time.

[0057] In systems where the preferred mode is static, centralized storage can be advantageous because traffic from the central storage can be kept to a minimum. It also allows for centralized allocation and management, thus enabling centralized nodes to broadcast updates. As an alternative to centralized storage, it is particularly beneficial in systems where the preferred mode may change more frequently, where a more distributed approach can be chosen, where information is cached more locally to avoid large amounts of traffic to the central gateway.

[0058] Alternatively, the network can be used to run specific applications. Examples of such applications include location or lighting applications. When such applications operate in a time-division multiplexing manner, it may be beneficial to adapt the communication pattern to the application at that time. Network nodes can adapt their operation accordingly, using predetermined rules or information about their communication partners' preferred communication patterns obtained directly or indirectly from the communication partners.

[0059] In an example embodiment of the first architecture, a dark node intends to send a message (e.g., a packet) via its network to a gateway that is also a Zigbee router. It chooses to send the packet to its parent node or next-hop node using the Zigbee protocol. Once the message reaches the parent or next-hop node, it can be further propagated within the Zigbee network maintained by the bright node according to the Zigbee routing protocol.

[0060] In another example embodiment, a dark node intends to send a message to all nodes in the network. It will send a broadcast message to its parent node using the Zigbee protocol. Its parent node will then also broadcast the message to other routers via the Zigbee protocol. Since other bright nodes are also Zigbee routers, they will be able to receive the message. For other dark nodes in the network, the best way to reach them is for the bright node to send them a BLE advertising message, which will be received at the dark node while it continuously listens for advertising channels. However, this requires the bright node to also send in BLE mode, which reduces the time it spends in Zigbee mode. This is acceptable as long as the network load for a single node to send is low, which is typical since there aren't that many lighting control messages throughout the day.

[0061] Furthermore, in the second structure, Figure 2 Dark nodes primarily operate in BLE mode (BLE router or BLE end device). Similarly, bright nodes primarily operate in Zigbee mode, but also act as BLE end devices. These combinations of device modes are possible because neither Zigbee nor BLE end devices need to constantly listen to their channels. They only need to be present on their channels when they have something to send.

[0062] In an example embodiment of the second architecture, a node (dark node or bright node) intends to send a message to a remote dark node or bright node. Then, its protocol stack's application layer (e.g., Figure 3 The control unit 38 can derive the most relevant pattern of the remote target node via an out-of-band mechanism. The application layer on the sending node then sends the message to the same protocol function as the remote receiving node. Since there are essentially two mesh networks with two (non-overlapping) router sets, the message will be received in either mesh network and further routed to the target node.

[0063] In another example embodiment of the second architecture, the application is predefined to use a certain protocol in the network. For example, lighting control messages are typically broadcast messages and are configured to use the BLE broadcast protocol, while sensor data reporting messages are typically unicast messages and are configured to use the Zigbee unicast or many-to-one protocol.

[0064] For broadcast-related applications, bright Zigbee routers and BLE end devices will send their messages to dark BLE router devices. Once it arrives there, the BLE router device should then retransmit it using both the BLE and Zigbee protocols to ensure reliable delivery to all nodes in the network.

[0065] For unicast-related applications, dark BLE end devices or routers will send Zigbee unicast messages to their parent bright Zigbee routers. Once it arrives there, the message will be routed using the Zigbee protocol. If the destination node is a dark node, the last-hop bright node will either convert the message into a BLE message or tunnel the Zigbee message within the BLE message to reliably reach the destination.

[0066] In another embodiment of the second architecture, particularly for broadcast messages, the source node can decide or be configured to use both protocols. In this way, it can send the same application message in both protocols and allow the message to propagate in both networks, rather than relying on other router devices. The number of routers in both modes can be configured to the minimum necessary level. Therefore, the broadcast network load in either mode can be manageable.

[0067] Figure 4 A flowchart illustrating the transmission process of a combined radio chip for achieving enhanced reliability according to various embodiments is shown.

[0068] In the first step S401, (for example by...) Figure 3 The control unit 38) determines the intended target node of the message. Then, in step S402, (for example, by...) Figure 3 The control unit 38) determines the underlying transmission-related applications and / or preferred network technologies at the target node. Based on the information obtained in step S402, in step S403, a network technology for transmission is selected (e.g., via...). Figure 3 (Switching unit 36). Subsequently, in step S404, a first receiving node (e.g., a parent node or next-hop node), if applicable, is selected for broadcast, unicast, multicast, or many-to-one transmission of the intent. Finally, in step S405, the message is transmitted to the target node via the selected first receiving node using the chosen protocol mode.

[0069] As a result, the protocol of the selected network technology used by the combined radio chip is chosen based on the preferences at the target or receiving node. Therefore, reliability can be enhanced when using combined radio equipment with a single RF front end.

[0070] In summary, a receiver-centric transmission system for IoT systems (such as lighting networks) has been described, featuring a combined protocol radio chip that allows two or more transmission protocols of different network technologies to share a single radio front end while preventing unacceptable performance degradation in one or both protocol modes. The receiver-centric approach allows for the implementation of two networks with acceptable performance on a single radio chip at each node, instead of requiring two radio chips per node.

[0071] While the invention has been illustrated and described in detail in the accompanying drawings and the foregoing description, such illustrations and descriptions are to be considered illustrative or exemplary and not limiting. The invention is not limited to the disclosed embodiments. The proposed reliability enhancement process can be applied to any possible combination of network technologies (e.g., single-hop and multi-hop network technologies). Furthermore, the invention can be applied to any product implementing multi-hop networks (e.g., Zigbee or others) or other network technologies interfaced with single-hop networks (e.g., BLE or others) or other network technologies. Examples include large-scale Zigbee lighting networks where individual lighting points are debugged via BLE using mobile devices such as smartphones or tablets. The invention is equally applicable to any other combination of single-hop technologies (e.g., BLE, infrared (IR), wireless LAN communication (Wi-Fi)) and multi-hop technologies (e.g., Zigbee PRO, Thread, Wireless HART, Smart RF, CityTouch, IP500, and any other mesh- or tree-based technologies).

[0072] By studying the accompanying drawings, the disclosure, and the appended claims, those skilled in the art can understand and implement other variations of the disclosed embodiments in practicing the claimed invention. In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite articles "a" or "an" do not exclude multiple. A single processor or other unit can perform the functions of several items listed in the claims. The mere fact that certain measures are listed in mutually different dependent claims does not indicate that a combination of these measures cannot be used advantageously.

[0073] The foregoing description details certain embodiments of the invention. However, it will be appreciated that, however detailed the foregoing may appear in the text, the invention can be practiced in many ways and is therefore not limited to the disclosed embodiments. It should be noted that the use of particular terms when describing certain features or aspects of the invention should not be construed as implying that the term is redefined herein as limited to include any particular characteristic of the feature or aspect of the invention associated with that term.

[0074] A single unit or device can perform the functions of several items listed in the claims. The mere fact that certain measures are listed in mutually different dependent claims does not indicate that a combination of these measures cannot be used advantageously.

[0075] Similar to Figure 4 The operations described herein can be implemented as program code devices and / or dedicated hardware for computer programs. Computer programs can be stored and / or distributed on suitable media such as optical storage media or solid-state media, supplied along with or as part of other hardware, such as via the Internet or other wired or wireless telecommunications systems, but can also be distributed in other forms.

Claims

1. A network node used in a network (100), the network node being configured to transmit or receive on a time-sharing basis according to a predetermined duty cycle in a first communication mode using a first network technology or a second communication mode using a second network technology, the network node including means for controlling transmissions of the network node in the network (100), wherein the means is characterized in that it comprises: The determining unit (38) is used to determine the preferred communication mode of the target node for transmission, wherein the preferred mode is the communication mode of the target node that is most frequently used in the first and second communication modes. and Selection unit (36) is used to select one of the first and second communication modes based on the preferred communication mode of the determined target node, for transmission to the target node. The preferred communication mode is based on information about the target node, which is retrieved directly from the target node, indirectly from other nodes or gateways, or generated by pre-configured rules.

2. The network node of claim 1, wherein the preferred communication mode is based on information about the target node, which is retrieved directly from the target node via an out-of-band mechanism or generated by pre-configured rules.

3. The network node according to claim 1, wherein, The network node is configured as a terminal device of the second network technology, and the terminal device, as a device of the first network technology, operates with a duty cycle of the first communication mode that is larger than the corresponding duty cycle of other communication modes.

4. The network node according to claim 1, 2, or 3, wherein, The first network technology is a single-hop technology, and the second network technology is a multi-hop technology.

5. The network node according to claim 4, wherein, The selection unit (36) is configured to select the second communication mode for transmission to the parent node or the next hop node if the determination unit (38) determines the gateway device of the network (100) as the target node of the transmission.

6. The network node according to claim 4, wherein, The selection unit (36) is configured to select the second communication mode to broadcast the transmission to the parent node if the determination unit (38) determines all network nodes of the network (100) as the target node of the transmission.

7. The network node according to claim 1, wherein, The network node can be configured to operate as a terminal device or router device of a first network technology, either with a duty cycle of a first communication mode that is larger than the corresponding duty cycle of other communication modes, or as a terminal device or router device of a second network technology, either with a duty cycle of a second communication mode that is larger than the corresponding duty cycle of other communication modes.

8. The network node according to claim 7, wherein, The determining unit (38) is configured to determine the preferred communication mode of the target node via an out-of-band mechanism, and wherein the selecting unit (36) is configured to select the determined preferred communication mode for transmission to the target node.

9. The network node according to claim 7, wherein, The determining unit (38) is configured to determine the preferred communication mode of the target node based on the application that the network node is operating for transmission, and wherein the selecting unit (36) is configured to select the determined preferred communication mode for transmission to the target node.

10. A lighting system comprising a plurality of network nodes as claimed in any one of claims 1-9.

11. The lighting system of claim 10, wherein the first network technology is used to receive beacon signals from the tag device (40) of the asset tracking system.

12. The lighting system of claim 10, wherein the plurality of network nodes includes a first network node configured as a terminal device of a second network technology and operating as a device of the first network technology with a duty cycle of a first communication mode that is larger than the corresponding duty cycles of other communication modes; and a second network node configured as a router device of the second network technology and operating with a larger duty cycle of the second communication mode, wherein, The second network node is configured to forward information from received broadcast messages of the second communication mode within an advertising message of the first communication mode.

13. The lighting system of claim 10, wherein the plurality of network nodes includes a first network node configured as a router device of a first network technology and operating with a larger duty cycle of a first communication mode, and a second network node configured as a terminal device or router device of a second network technology and operating with a larger duty cycle of a second communication mode. in, The first network node is configured to forward broadcast messages received in the first communication mode in both the first and second communication modes, or The second network node is configured to: if the next-hop node is the first network node, convert the received unicast message of the second communication mode into a message of the first communication mode, or tunnel the received unicast message in the message of the first communication mode.

14. A method for controlling the transmission of network nodes in a network (100), said network nodes being configured to transmit or receive based on time sharing according to a predetermined duty cycle in a first communication mode using a first network technology and a second communication mode using a second network technology, wherein the method is characterized in that it comprises: Determine the preferred communication mode for the target node of the transmission, wherein the preferred mode is the communication mode of the target node that is most frequently used in the first and second communication modes; as well as Based on the preferred communication mode of the determined target node, one of the first and second communication modes is selected for transmission to the target node. The preferred communication mode is based on information about the target node, which is retrieved directly from the target node, indirectly from another node or gateway, or generated by pre-configured rules.

15. A computer program product comprising code means for performing the steps of claim 14 when executed on a network node.

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