Node device

Abstract

A node device for a multi-hop heterogeneous wireless network includes a transceiver, memory, and a processor. The transceiver is configured to transmit and receive general data in a DODAG topology and priority data in an optimal routing topology. The memory is configured to store a computer-executable program and parameters, including communication mode, number of multimode links, route overlap, neighbor information, route transmission time, and route length. The processor is configured to execute steps of the computer-executable program, including exploring general data routes and priority routes, wherein exploring priority routes further includes exploring non-cyclic routes, exploring minimum overlap routes, exploring minimum transmission time routes, and exploring minimum route length routes.

Description

Technical Field

[0001] The present invention relates to the routing of data in a wireless communication network, and more particularly to the routing of heterogeneous data in a next-generation wireless communication network. Prior Art

[0002] With the rise of 5G and other communication technologies, consumer wireless devices are evolving from contemporary to next-generation. Next-generation wireless devices can support multiple communication modes / interfaces and perform more functions. During the development phase, it is impractical to use next-generation devices to completely replace the deployed contemporary devices. Therefore, the next-generation wireless network will consist of current and next-generation nodes. Thus, since existing routing protocols are typically designed for contemporary networks, how to effectively route different data in the next-generation wireless network needs to be addressed.

[0003] Therefore, there is a need to provide a new routing architecture to transmit different data in the next-generation Internet of Things network. Summary of the Invention

[0004] Some embodiments of the present invention are based on the understanding that consumer wireless devices are evolving from contemporary to next-generation, where contemporary devices support a single communication mode / interface and / or perform a simple function, where next-generation devices can support multiple communication modes / interfaces and / or perform more functions, and where devices that support a single communication mode are called single-mode, and devices that support multiple communication modes / interfaces are called multi-mode.

[0005] Some embodiments of the present invention are based on the understanding that considering cost and service continuity, it is impractical to use next-generation devices to completely replace the deployed contemporary devices during the development phase of consumer devices.

[0006] To this end, an object of various embodiments of the present invention is to form a next-generation wireless Internet of Things network using a data concentrator, contemporary nodes, and next-generation nodes, where the data concentrator is regarded as a multi-mode node, the contemporary nodes are regarded as single-mode general data nodes, and the next-generation nodes are divided into multi-mode general data nodes, single-mode priority data nodes, and multi-mode priority data nodes, where the contemporary nodes and the next-generation multi-mode general data nodes only collect general data, the next-generation single-mode priority data nodes and the next-generation multi-mode priority data nodes collect general data and priority data, and nodes that only collect general data are called D-nodes, and nodes that collect general data and priority data are called P-nodes.

[0007] The cognitive basis of some embodiments of the present invention is that route discovery is inevitable in multi-hop wireless networks because at least one data node in a multi-hop wireless network cannot communicate directly with the data concentrator and requires other data nodes to relay in order to communicate with the data concentrator.

[0008] Therefore, various embodiments of the present invention form two routing topologies applicable to next-generation Internet of Things networks, where the general topology is used to transmit general data and the priority topology is used to transmit priority data. The general route (referred to as D-route) in the general topology is obtained by exploring all data nodes using a distance-based method. The priority route (referred to as P-route) in the priority topology is obtained by minimizing route overlap, route transmission, and route length only for priority nodes. The efficiency of the D-route is relatively low, and the efficiency of the P-route is relatively high.

[0009] The cognitive basis of some embodiments of the present invention is that nodes in next-generation Internet of Things networks can be single-mode nodes or multi-mode nodes. Single-mode nodes support low-speed communication modes, while multi-mode nodes support low-speed communication modes and high-rate communication modes. For interoperability, the low-speed communication mode of multi-mode nodes must be the same as the low-rate communication mode of single-mode nodes.

[0010] Therefore, various embodiments of the present invention form low-speed links and high-speed links in the routing topology. The low-rate links are formed between two single-mode nodes or between a single-mode node and a multi-mode node, while the high-rate links are only formed between two multi-mode nodes.

[0011] The cognitive basis of some embodiments of the present invention is that priority nodes in next-generation Internet of Things networks can collect general data and priority data. Priority data has a higher priority than general data, and the transmission of priority data has a higher priority than the transmission of general data.

[0012] Therefore, various embodiments of the present invention provide priority-based data routing. When a data node has general data and priority data to transmit or relay, the priority data will be transmitted first. Therefore, an object of various embodiments of the present invention is to provide a distributed D-route discovery method and a centralized P-route discovery method.

[0013] Therefore, D-route discovery takes into account the existence of multi-mode nodes in the next-generation Internet of Things network, where these nodes are organized into a Destination Oriented Directed Acyclic Graph (DODAG) of destinations in the D-route topology. The DODAG Information Object (DIO) message contains a communication mode (CM), where CM = 1 represents a single-mode node and CM = 2 represents a multi-mode node. The CM is used to calculate the multi-mode link count (MLC) metric, which represents the number of multi-mode links in the entire route. A route with a smaller MLC is composed of fewer multi-mode links, while a route with a larger MLC is composed of more multi-mode links. When other conditions are the same, the data node selects a route with a larger MLC. In addition, the Destination Advertisement Object (DAO) message contains the accumulated traffic load (ATL), and the ATL parameter can be used to calculate the route communication time (RCT) metric. When other conditions are the same, the data node selects a route with a smaller RCT.

[0014] The cognitive basis of some embodiments of the present invention is that route overlap delays data transmission and causes data loss. P-route discovery depends on the number of nodes, the number of priority nodes, and the deployment of nodes in the network. P-route discovery may not always discover non-overlapping P-routes, but it can minimize P-route overlap.

[0015] Therefore, the best P-routes are explored to minimize objectives such as route overlap, route transmission time, and route length. Thus, it is inevitable to calculate the degree of route overlap. However, the existing route overlap calculation is defined for point-to-point (P2P) routes and is not suitable for multi-point-to-point (MP2P) routes where all routes have the same destination node, which does not transmit any data and should not be included in the route overlap calculation.

[0016] An objective of some embodiments is to define the route overlap of MP2P routes as the sum of the overlaps of individual forwarding nodes in the route, where a forwarding node is a node that transmits or relays data on the route. Mathematically, the route overlap is the total number of times the route passes through the forwarding node repeatedly.

[0017] The cognitive basis of some embodiments of the present invention is that loop routing is inefficient because it has long delays, wastes communication bandwidth and node resources, and interferes with other routes. Therefore, it is necessary to explore acyclic P-routing.

[0018] Therefore, some embodiments of the present invention provide a recursive acyclic routing exploration method for exploring an acyclic route from a priority node to a data concentrator in a next-generation Internet of Things network, where the recursive acyclic routing exploration starts from a priority node and extends the route hop by hop until the route reaches the data concentrator or the route can no longer be extended without loops.

[0019] The cognitive basis of some embodiments of the present invention is that the maximum number of non-overlapping routes that can be explored is equal to the number of physical neighbors of the data concentrator.

[0020] For this reason, the goal of some embodiments is to explore P-routes for priority nodes to minimize route overlap, where P-route exploration is formulated as a non-linear optimization problem.

[0021] Some embodiments of the present invention provide a node device for use in a multi-hop heterogeneous wireless network including single-mode nodes and multi-mode nodes. The node device may include a transceiver, a memory, and a processor. The transceiver is configured to send and receive messages to explore a general data route (D-route), where the explored D-routes form a DODAG topology, and where the transceiver is configured to send and receive general data messages in the DODAG topology and send and receive priority data in an optimal route topology. The memory is configured to store computer-executable programs and DODAG topology configuration parameters, the DODAG topology configuration parameters including rankings, communication modes (CMs), and multi-rate link counts (MLCs) specified by the Routing Protocol for Low-Power and Lossy Networks (RPL) of Internet Protocol version 6 (IPv6). The processor is configured to execute a plurality of steps of the computer-executable program, the steps including exploring D-routes of all data nodes through the use of the Routing Protocol for Low-Power and Lossy Networks of IPv6 to form a DODAG topology, where the Routing Protocol for Low-Power and Lossy Networks of IPv6 uses DODAG Information Object (DIO) messages for an upward route exploration procedure and uses Destination Advertisement Object (DAO) messages for a downward route exploration procedure. The steps further include exploring neighboring nodes while exploring D-routes, where when the processor receives a broadcast DIO message from another node through the transceiver, the processor treats the other node as a neighbor node. The steps further include using the transceiver to transmit an accumulated traffic load (ATL) and an identifier of a neighboring node to a data concentrator through a DAO message.

[0022] In addition, some embodiments of the present invention provide a node device for a multi-hop heterogeneous wireless network including a multi-mode concentrator. The node device may include a transceiver, a memory, and a processor. The transceiver is configured to send DIO messages to initiate general data route discovery and receive DAO messages to set up a downward general data route. The transceiver is further configured to obtain the accumulated traffic load (ATL) and neighbor information of data nodes for optimal priority route discovery to construct an optimal route topology, wherein the transceiver is configured to send the optimal route topology to data nodes on the discovered priority route to transmit priority data to the multi-mode concentrator, wherein the transceiver is configured to receive general data in the DODAG topology and receive priority data in the optimal route topology. The memory is configured to store computer-executable programs and parameters, the parameters including a communication mode (CM), ATL, neighbor set, degree of route overlap (DRO), and optimal priority route discovery. The processor is configured to execute a plurality of steps of the computer-executable program, the steps including using the IPv6 low-power lossy network routing protocol to discover D-routes of all data nodes, wherein the IPv6 low-power lossy network routing protocol uses DIO messages for upward route discovery procedures and uses DAO messages for downward route discovery procedures. The steps further include discovering an optimal priority route by formulating the P-route discovery problem as a non-linear optimization problem to minimize the route overlap calculated using DRO, wherein the discovered optimal priority route is further optimized to minimize the route transmission time and route length.

[0023] The cognitive basis of some embodiments is that the problem of minimum overlap route discovery can be a multi-solution problem, and there are multiple sets of P-routes that can minimize route overlap.

[0024] Therefore, some embodiments of the present invention provide a method to find a set of minimum overlap P-routes that minimizes the total route transmission time.

[0025] In addition, some embodiments of the present invention also provide a method to find a set of minimum overlap P-routes that minimizes the total route length.

[0026] The embodiments of the present disclosure will be further described with reference to the accompanying drawings. The accompanying drawings shown are not necessarily drawn to scale, and the emphasis should be placed on explaining the principles of the embodiments of the present disclosure. Brief Description of the Drawings

[0027] Figure 1 is a schematic diagram of a next-generation wireless Internet of Things network composed of a data concentrator, contemporary nodes, and next-generation nodes. Figure 2 shows the node classification in the next-generation wireless Internet of Things network, where the data concentrator is a multi-mode node, the contemporary nodes are general single-mode nodes, and the next-generation nodes include multi-mode general nodes, single-mode priority nodes, and multi-mode priority nodes. Figure 3 shows an example of a dual-topology routing architecture in the next-generation wireless Internet of Things network. Figure 4 illustrates examples of loop routing and non-loop routing in the next-generation wireless Internet of Things network. Figure 5 depicts an example of a sub-routing of the route from priority node p to data concentrator C in the MP2P routing topology of the next-generation wireless Internet of Things network. Figure 6 shows examples of end nodes and non-end nodes in the non-loop P-routing exploration in the next-generation wireless Internet of Things network. Figure 7 shows the sub-routing extension and elongation of priority nodes in the non-loop P-routing exploration in the next-generation wireless Internet of Things network. Figure 8A shows an algorithm for establishing a non-loop routing exploration for priority nodes in the next-generation wireless Internet of Things network. Figure 8B shows an algorithm for recursively extending and elongating the non-loop sub-routes of priority nodes in the next-generation wireless Internet of Things network. Figure 9 is an algorithm for exploring the minimum overlapping routes of all priority nodes in the next-generation wireless Internet of Things network. Figure 10 illustrates the time allocation of priority data transmission and general data transmission in the next-generation wireless Internet of Things network. Embodiments

[0028] Although the above figures describe the embodiments of the present disclosure, as pointed out in the discussion, other embodiments can also be envisioned. The present disclosure presents illustrative embodiments in a manner of expression rather than limitation. Those skilled in the relevant art can make many other modifications and embodiments within the scope and spirit of the principles of the embodiments of the present disclosure.

[0029] In contemporary Internet of Things (IoT) networks, devices typically have fewer resources and perform simple functions, such as being battery-powered, supporting the IEEE 802.15.4 communication protocol, and using a Frequency-Shift Keying (FSK) modulation scheme for data transmission. On the other hand, next-generation IoT networks usually consist of a mix of contemporary and next-generation devices. Next-generation devices have more resources and can perform more functions, such as using grid power, supporting both the IEEE 802.15.4 and LTE / 5G communication protocols simultaneously, and using both FSK and Quadrature Amplitude Modulation (QAM) modulation schemes. Therefore, next-generation devices in next-generation IoT networks can play multiple roles. Take the upcoming next-generation smart meter network as an example. This network will be composed of contemporary meters and next-generation meters. Contemporary meters only collect measurement data and periodically transmit the measurement data to a data concentrator. However, next-generation meters can 1) collect measurement data and power information, or 2) support multiple communication modes / interfaces, or 3) collect both types of data (measurement data and power information) and support multiple communication modes / interfaces. The power information is transmitted in the last gasp message. In the smart meter network, the power information is used for predictive maintenance and diagnosing the causes of abnormal events (such as power outages), so it is crucial for power suppliers. Therefore, the power information will have a higher priority than general measurement data. Thus, next-generation meters that can collect power information are also called priority meters. Therefore, in addition to periodically transmitting measurement data, priority meters also need to effectively transmit event-based last gasp messages.

[0030] In next-generation IoT networks, nodes can be classified according to different criteria, such as: (1) role as a data source or data destination, (2) communication capabilities, (3) data collection capabilities. According to criterion 1), nodes that collect data are called data nodes, and nodes that aggregate data are called data concentrators. According to criterion 2), nodes that support one communication mode are called single-mode nodes, and nodes that support multiple communication modes / interfaces are called multi-mode nodes. In particular, data concentrators are multi-mode nodes. According to criterion 3), nodes that only collect general data are called general nodes, and nodes that collect both general data and priority data are called priority nodes.

[0031] FIG. 1 is a schematic diagram of a next-generation wireless Internet of Things network, which consists of a data concentrator 100, a contemporary single-mode general data node 110, a next-generation multi-mode general data node 120, a next-generation single-mode priority data node 130, and a next-generation multi-mode priority data node 140. These nodes form a multi-hop mesh network, in which data packets generally flow from data nodes (contemporary nodes or next-generation nodes) to the data concentrator 100, but control messages can be sent in either direction. At least one data node cannot communicate directly with the data concentrator 100, so an intermediate node is needed to relay the communication. Single-mode nodes can only support low-speed communication modes, but multi-mode nodes can support both low-speed and high-speed communication modes simultaneously. Therefore, low-speed links 150 are formed between two single-mode nodes, or between a single-mode node and a multi-mode node. On the other hand, high-speed links 160 can only be formed between two multi-mode nodes. Single-mode nodes include the contemporary general data node 110 and the next-generation single-mode priority data node 130. Multi-mode nodes include the next-generation multi-mode general data node 120, the next-generation multi-mode priority data node 140, and the data concentrator 100.

[0032] FIG. 2 shows the node classification of the next-generation wireless network. In the next-generation Internet of Things network 200, nodes are first classified into data nodes 210 and a data concentrator 220. The data concentrator 220 is regarded as a multi-mode node 230. The data nodes 210 are further classified into contemporary data nodes 240 and next-generation data nodes 260. The contemporary data nodes 240 are classified into single-mode general data nodes 250, and the next-generation data nodes 260 are classified into multi-mode general data nodes 270, single-mode priority data nodes 280, and multi-mode priority data nodes 290.

[0033] To transfer data in a multi-hop Internet of Things network, routing is inevitable. Routing has been widely studied for many years. The concept of routing is simple. However, the routing problem is a highly complex problem, including two processes: route discovery and routing scheduling. Route discovery can be a Non-deterministic Polynomial Complete (NP-complete) problem. For example, maximizing the throughput of a multi-hop wireless network in wireless interference has been proven to be NP-hard. The centralized and decentralized routing scheduling problems in a two-dimensional mesh topology have also been proven to be NP-complete problems, which further increases the complexity of the routing scheduling problem.

[0034] Well-known routing discovery protocols include: Dijkstra's shortest path algorithm, dynamic source routing (DSR), ad-hoc on-demand distance vector (AODV) routing, and the Routing Protocol for Low-Power and Lossy Networks (RPL) of Internet Protocol version 6 (IPv6). However, these routing protocols are not used to handle data heterogeneity and node heterogeneity. For example, RPL sends all uplink traffic to a default parent and uses the same network configuration parameters for all nodes. Therefore, it is necessary to address the challenges that arise in next-generation IoT networks.

[0035] In order to make next-generation IoT networks operate efficiently, there are many problems that need to be solved. Route overlap is one of the problems to be solved in next-generation IoT networks, especially the transmission of priority data. Route overlap significantly affects network performance. Overlapping routes delay data transmission and cause data loss in wireless networks. Therefore, in order to enhance the reliability of priority data transmission, it is necessary to minimize route overlap, especially for the routes used to transmit priority data.

[0036] The present invention provides a two-topology routing architecture for next-generation IoT networks, a general topology for general data transmission, and a priority topology for priority data transmission. The routes in the general topology are called regular data routes (D-Routes), and the routes in the priority topology are called priority routes (P-Routes). Regular data routes can be discovered for all data nodes in the network, but P-Routes can only be discovered for priority data nodes. D-Routes are discovered using a method based on traditional protocols. However, P-Routes are discovered using the optimal method of the present invention, which describes P-Route discovery as an optimization problem. Therefore, P-Routes are the best routes that minimize route overlap, route transmission time, and route length.

[0037] Figure 3 shows an example of a dual-topology routing architecture for the next-generation Internet of Things network. The network includes a data concentrator C, two next-generation multimode general data nodes 1 and 5, three next-generation single-mode priority data nodes 2, 6, and 14, and ten contemporary single-mode data nodes 3, 4, 7, 8, 9, 10, 11, 12, 13, and 15. The dashed routing 300 with arrows represents the D-routing for general data transmission in the routing topology. These distance-based routes are explored using the traditional RPL protocol. The solid routing 310 with arrows represents the P-routing for priority data transmission in the routing topology. These routes are explored using the optimal method of the present invention. The routing of priority data node 2, priority data node 6, and priority data node 14 is different in the two topologies. In the general topology, the routes 2→C, 6→2→C, and 14→9→3→C overlap at node 2. However, the routes 2→C, 6→5→1→C, and 14→9→3→C do not overlap. In addition, the links 5→1 and 1→C are high-speed links, and the P-routing uses these high-speed links. However, the D-routing does not utilize these high-speed links. Assume that the physical layer (PHY) data rates of the low-speed communication mode and the high-speed communication mode are 100 kbps and 800 kbps, respectively. It takes 8 milliseconds (ms) for the low-speed link to transmit a 100-byte packet. However, the high-speed link only takes 1 ms. In addition, Internet of Things devices are usually half-duplex. Considering wireless link interference and ignoring random backoff delay, the D-routing takes 32 ms to transmit three priority packets. On the other hand, the P-routing only takes 26 milliseconds. These results show that although the P-routing may be longer, it is more efficient. - [Necessity of Multi- Topology Routing] []

[0038] With the advent of 5G and other communication technologies, consumer Internet of Things (IoT) devices are evolving from the current generation to the next generation. Current-generation devices have fewer resources and can only perform simple functions, such as supporting a single communication mode (referred to as single-mode devices) and collecting general data. On the other hand, next-generation devices have more resources and can perform more functions, such as supporting multiple communication modes / interfaces (referred to as multi-mode devices), and / or collecting general data and priority data (referred to as priority devices). However, during the transition phase, it is impractical to completely remove the deployed current-generation devices. Take the next-generation smart meter network as an example. This network will consist of current-generation general meters and next-generation priority meters. General meters regularly collect and send measurement data. However, priority meters not only collect general measurement data but also sense power information. Power information can be used for predictive maintenance and diagnosing the causes of abnormal events (such as power outages), so it is crucial for power suppliers. Therefore, power information has a higher priority than general measurement data. Thus, in addition to general measurement data, priority meters also need to efficiently transmit power information. Therefore, a new routing architecture is needed to deliver heterogeneous data in the next-generation IoT network. For this reason, how to effectively route different data in the next-generation IoT network is a problem that needs to be solved.

[0039] Although the routing of the current generation of IoT networks has been widely studied, the routing of the next-generation IoT network has not been well studied. The present invention provides a dual-topology routing architecture for the next-generation IoT network, a general topology for general data transmission, and a priority topology for priority data transmission. The routing in the general topology is called D-routing, and the routing in the priority topology is called P-routing. A data node that only collects general data is called a D-node, and a data node that collects both general data and priority data is called a P-node. D-routing can be explored for all data nodes in the network, but P-routing can only be explored for priority data nodes. D-routing is explored using a distance-based method. However, P-routing is explored using an optimal method that formulates the routing exploration as an optimization problem. Therefore, P-routing is the optimal routing that minimizes routing overlap, routing transmission time, and routing length.

[0040] Embodiments of the present invention consider a next-generation IoT network, including: a data concentrator, a set of N general data nodes (referred to as D-nodes), and a set of M priority data nodes (referred to as P-nodes), where the D-nodes and P-nodes can be single-mode or multi-mode. The data concentrator is regarded as a multi-mode node. Low-speed mode communication is used between single-mode nodes and between single-mode nodes and multi-mode nodes. High-speed mode is only used between multi-mode nodes. The D-nodes and P-nodes are randomly deployed. - [Distributed] [D-Routing Discovery] [Routing Exploration] []

[0041] Embodiments of the present invention improve the RPL routing protocol for D-routing exploration. RPL uses DODAG Information Object (DIO) messages for upward routing exploration and Destination Advertisement Object (DAO) messages for downward routing construction. To implement P-routing exploration, each data node also performs neighbor discovery during D-routing exploration. If a node receives a DIO message broadcast by another node, the node considers the other node as a neighbor. Once the D-routing exploration ends, each data node transmits its neighbor information to the data concentrator through DAO messages.

[0042] The DIO message carries the communication mode and the number of multi-mode links. The information carried by the DIO message allows nodes to obtain DODAG configuration parameters for parent selection (i.e., routing selection). In the present invention, the communication mode (CM) and the multi-mode link count (MLC) are also in the DIO message. When CM = 1, it represents the single mode, and when CM = 2, it represents the multi-mode. Using the CM parameter, the MLC metric can be calculated to represent the number of multi-mode links along the route (i.e., the number of high-speed links along the route). The CM of the data concentrator is set to 2 and the MLC is set to 0. During the D-routing exploration process, if and only if a node and the sender of the DIO message are both multi-mode nodes, the node increments the MLC by one. Data nodes use the RPL rank metric and the MLC metric to select a parent. If the RPL ranks of candidate parents are the same, the data node selects the route with a larger MLC because it consists of more high-speed links. The RPL rank is a distance-based metric used to represent the node's position relative to the data concentrator in the DODAG topology. When the rank value is smaller, it means the node is closer to the data concentrator. When the rank value is larger, it means the node is farther from the data concentrator.

[0043] The DAO message carries the cumulative traffic load, neighbor information, and communication mode. The traffic load significantly affects network performance but has not been well addressed by the RPL routing protocol. In the present invention, each data node includes the cumulative traffic load in the DAO message. In the RPL protocol, a data node not only sends its own data but also forwards the data of its child nodes to the default parent. Therefore, the cumulative traffic load (ATL) of data node n can be expressed as (1) where is the traffic load of node n, is the number of child nodes of node n, (k = 1, 2,..., ) are the child nodes of node n. The ATL information is used for P-route discovery. In addition, in the D-route discovery process, a data node can find its neighbors through the received DIO messages, which are sent by all nodes in the network according to the RPL protocol. If a data node receives a DIO message from another node, then the node will regard the other node as a neighbor. The neighbor information is a set of the identification codes of the neighbors of the data node. In addition, the data node also includes its communication mode (CM) in the DAO message. - [Centralized] [P-] [Route Discovery] []

[0044] Once the neighbor information is obtained, the data concentrator C can explore the best P-route of the P-nodes. The set of P-nodes in the network is denoted as , and the P-route from P-node to the data concentrator C → → → … →C is denoted as ( ). Then, the set is composed of the nodes that transmit or forward data during the priority data transmission process in the P-route , so this set is called the forwarding set of the P-route , and the nodes in this set are called forwarding nodes.

[0045] There are different definitions of route overlap. A prior art defines the overlap of links (edges) as route overlap. However, this definition may undercount some route overlaps. For example, in Figure 3, the routes (11, 5, 1, C) and (12, 5, 2, C) overlap at node 5, but there is no link overlap between these two routes. Another prior art defines route overlap as the sum of all single-node overlaps between any pair of routes. For P2P routing, this node-based overlap definition may overcount the overlap of MP2P routes. For example, since the data concentrator C does not transmit data, there is only one valid node overlap between the aforementioned two routes at node 5, but under this definition, there will be two node overlaps, one at node 5 and the other at node C.

[0046] An embodiment of the present invention defines the route overlap of MP2P routes, which excludes the data concentrator C from the calculation of route overlap. Route The degree of route overlap (DRO) of a route is defined as the sum of the overlaps of each forwarding node in the route (i.e., the total number of times the route repeatedly passes through the forwarding node). For example, the aforementioned forwarding node 5 is repeated once. To calculate DRO mathematically, let the length of the route be represented as , and let the total number of individual forwarding nodes on the route be represented as . The calculation of DRO for the route is as follows: - - [Non-cyclic] [(Acyclic)] [Route exploration] []

[0047] The efficiency of cyclic routing is not high. Figure 4 shows examples of acyclic routing and cyclic routing, where routing 400 (12, 6, 7, 3, C) is acyclic routing, and routing 410 (11, 5, 1, 4, 5, 2, C) is cyclic routing because 5 → 1 → 4 → 5 is a cycle.

[0048] If and only if the following conditions are satisfied, the MP2P routing =( , , , …, , ) is an acyclic routing: 1. 2. , , …, 3. is adjacent to , , ..., 4. The data concentrator C is adjacent to 5. Only is adjacent to the data concentrator C

[0049] The P-node The set of all acyclic routes is denoted as . The data nodes that can communicate directly with the data concentrator C (i.e., the physical neighbors of node C) are called directly connected nodes, and other data nodes are called non-directly connected nodes. It should be noted that directly connected nodes may be different from single-hop (1-hop) nodes because connections reflect physical connectivity, while hops reflect logical connectivity. Single-hop nodes are directly connected nodes, but directly connected nodes are not necessarily single-hop nodes. The set of neighbors of node n is denoted as . For directly connected nodes , only one acyclic route is constructed (i.e., ). For non-directly connected nodes ​ , the present invention provides a recursive method for exploring acyclic routes. The recursive method extends and expands an acyclic sub-route hop-by-hop from the source node until reaching the data concentrator C.

[0050] Figure 5 depicts an example of sub-route 500 on the P-route from the priority node to the data concentrator C within the multi-point-to-point (MP2P) routing topology in the next-generation wireless Internet of Things network.

[0051] Before introducing the recursive acyclic route exploration algorithm, first define the end node.

[0052] Definition: The end node is the data node where the extension of the acyclic sub-route ends, meaning the sub-route cannot be extended without a cycle.

[0053] The end node is different from the leaf node. The end node is a leaf node, but a leaf node is not necessarily an end node. The determination of the end node depends on the sub-route to be extended. A node can be the end node of the extension of one sub-route, but it may not be the end node of the extension of another sub-route. In Figure 6, node 11 is not the end node for extending sub-route (10,4), but it is the end node for extending sub-route (4,5).

[0054] Mathematically, node is the end node for extending sub-route = ( ) if and only if the set , where . Therefore, at the k-th hop, (1) if node is a directly connected node, then sub-route Completion of extension (2) If the node is an end node, then the sub - route extension ends (3) Otherwise, continue. The set is called the extendable set of nodes of the sub - route If the set contains more than the nodes, then the sub - route will be expanded at the node Expand.

[0055] Figures 8A and 8B depict the acyclic routing discovery algorithm, where Algorithm 1 provides the initialization of acyclic routing discovery and Algorithm 2 provides the recursive acyclic sub - route expansion. For non - directly connected nodes , make , Algorithm 1 establishes h single - hop sub - routes. Algorithm 1 then calls Algorithm 2 to recursively extend and expand each sub - route. For example, to extend the sub - route 700 of the non - directly connected node at the k - th hop, let , Figure 7 shows that there are m ways 701 to extend the acyclic sub - route 700 (i.e., the sub - route 700 is extended into m sub - routes). Therefore, during the recursive sub - route extension process of Algorithm 2, the sub - route can be expanded at each hop, such that the sub - route can be extended and expanded into multiple sub - routes at each hop.

[0056] The outputs of Algorithm 1 and Algorithm 2 are acyclic routing sets of P-nodes . Algorithm 2 introduces a routing length threshold for the reason that: Although minimizing routing overlap is expected, overly long routes are not desired. To remove the restriction on routing length, the routing length threshold can be set to infinity. - [Minimum Overlap] [P-] [Routing Exploration] []

[0057] Non-overlapping P-routes are not always able to be explored, for example: more than 3 P-nodes in Figure 3. The goal is to minimize routing overlap. Once an acyclic routing of P-nodes is explored, the next step is to find an acyclic routing that minimizes the DRO. This problem can be described as an optimization problem, that is, to separately find routes for P-nodes such that (3)

[0058] It can be seen that provides an ideal (i.e., all routes do not overlap) solution.

[0059] Problem (3) is a difficult-to-solve non-linear optimization problem, especially for large and dense networks with a large number of acyclic routes. In fact, problem (3) belongs to the combinatorial optimization problem and is a weakly NP-hard problem.

[0060] To solve problem (3), the present invention provides a greedy heuristic method, as shown in Algorithm 3 of Figure 9, where represents the set of minimum overlap routing IDs. The routing length threshold will affect the complexity of Algorithm 3.

[0061] Problem (3) can be a multi-solution problem. For example, the routes (2, C), (6, 5, 1C), (14, 9, 3, C) and the routes (2, C), (6, 5, 4, 1, C), (14, 8, 3, C) in Figure 3 are two non-overlapping sets of route collections. Therefore, the minimum overlapping routes can be further optimized based on other metrics (such as route transmission time and route length). It should be emphasized that in a network without multi-mode nodes, the shortest route length may result in the shortest transmission time. However, when there are multi-mode nodes, these two objectives may yield different solutions. - [Shortest Transmission Time] [P-] [Route Exploration] []

[0062] The route transmission time (RTT) is a metric for calculating the data transmission time of an entire route. For a route , assuming the rates , , …, are the maximum transmission rates of the links , [ , …, [ respectively. Then, the RTT of the route is calculated as: (4) where is the expected transmission quantity of node ( ). For the set of minimum overlapping routes labeled as , the total RTT is (5)

[0063] The goal of the shortest transmission time P-route exploration is to find a set of minimum overlapping routes for the P-nodes respectively that can minimize the total RTT: (6) - [Shortest Length] [P-] [Route Exploration]

[0064] For the one composed of A set of identified minimum - overlapping routes, the total route length can be expressed as: (7)

[0065] The goal of the shortest - length P - route exploration is to find routes for P - nodes respectively that can minimize the total route length: (8) - [Data concentrator transmits to data nodes] [P -] [route] []

[0066] When the data concentrator C discovers the priority route for priority data transmission, the data concentrator C transmits the priority route not only to the priority nodes but also to the general nodes. Thus, the priority nodes know the P - route to transmit priority data, and all nodes in the network know the P - route to relay priority data.

[0067] A data node may have both general data and priority data to transmit or relay at the same time. In this case, the data node should first use the priority route to transmit or relay the priority data. This means that the priority route has a higher priority than the general route. - [Data concentrator allocates time for priority data transmission] []

[0068] Priority data has a higher priority than general data. However, general data transmission may compete for resources with priority data transmission, thus delaying priority data transmission. Therefore, the data concentrator C can divide the time into time periods as shown in Figure 10, where the priority period (PP) 1000 is only used for priority data transmission, and the data period (DP) 1010 can be used for both general data and priority data transmission. The data concentrator C can transmit the time - period information to all data nodes in the network.

[0069] The above description only provides exemplary embodiments and is not intended to limit the scope, applicability, or configuration of the present disclosure. Instead, the following description of the exemplary embodiments provides a feasible description for those skilled in the relevant art to implement one or more exemplary embodiments. Without departing from the spirit and scope of the claimed subject matter, changes can be made to the functions and configurations of each element.

[0070] Although the present disclosure describes the present invention through preferred embodiments, it should be understood that various other modifications can be made within the spirit and scope of the present invention. Therefore, the purpose of the appended claims is to cover all variations and modifications that fall within the true spirit and scope of the present invention.

[0071] 100, C: Data concentrator 110, 3, 4, 7, 8, 9, 10, 11, 12, 13, 15: Contemporary single-mode general data nodes 120, 1, 5: Next-generation multi-mode general data nodes 130, 2, 6, 14: Next-generation single-mode priority data nodes 140: Next-generation multi-mode priority data node 150: Low-speed link 160: High-speed link 200~290: Node classification of next-generation wireless networks 300: Dotted-line routing 400, 410: Routing 700: Sub-routing 701: Method

[0072] None

Claims

1. A node device for a multi-hop heterogeneous wireless network including a number of complex single-mode data nodes and a number of complex multi-mode data nodes, the node device comprising: A transceiver configured to send and receive multiple messages to explore multiple general data routes (D-routes), wherein the explored D-routes form a destination-oriented directed acyclic graph (DODAG) topology, wherein the transceiver is configured to send and receive general data on the DODAG topology and to send and receive priority data on an optimal route topology; a memory configured to store multiple computer-executable programs and multiple DODAG topology configuration parameters, including a ranking, a communication mode (CM), and a multimode link count (MLC), wherein the ranking is specified by the Internet Protocol Version 6 (IPv6) Low Power Lossless Routing Protocol; And a processor configured to execute a plurality of steps of the computer-executable program, wherein the steps include: exploring the D-routes of all data nodes using the IPv6 Low Power Loss Routing Protocol to form the DODAG topology, wherein the IPv6 Low Power Loss Routing Protocol uses a DODAG Information Object (DIO) message for an upward route exploration procedure and a Destination Advertisement Object (DAO) message for a downward route exploration procedure; exploring a plurality of neighboring nodes while exploring the D-routes, wherein when the processor receives a broadcast DIO message from another node via the transceiver, the processor considers that other node as one of the neighboring nodes; and using the transceiver to transmit the Accumulated Traffic Load (ATL) and the identifiers of the neighboring nodes to a data concentrator via the DAO message, wherein the DIO message carries parameters specified by the IPv6 Low Power Loss Routing Protocol, as well as other parameters, to select a parent (a route) in the DODAG topology. The DIO message carries the ranking, communication mode (CM), and number of multimode links (MLC) specified by the IPv6 Low Power Lossy Network Routing Protocol. The communication mode (CM) is configured to calculate the number of multimode links (MLC), and the number of multimode links (MLC) is configured to perform routing selection. When multiple candidate parent rankings are the same, the node device selects the route with the larger number of multimode links (MLC).

2. The node device as described in claim 1, wherein the data concentrator and the multimode data nodes set the communication mode (CM) to 2, and the single-mode data nodes set the communication mode (CM) to 1, wherein the data concentrator sets the number of multimode links (MLC) to 0, wherein the node device increments the number of multimode links (MLC) by one when the node device and the sender of the DIO message belong to the multimode data nodes.

3. A node device for a multi-hop heterogeneous wireless network including a number of complex single-mode data nodes and a number of complex multi-mode data nodes, the node device comprising: A transceiver configured to send and receive multiple messages to explore multiple general data routes (D-routes), wherein the explored D-routes form a destination-oriented directed acyclic graph (DODAG) topology, wherein the transceiver is configured to send and receive general data on the DODAG topology and to send and receive priority data on an optimal route topology; a memory configured to store multiple computer-executable programs and multiple DODAG topology configuration parameters, including a ranking, a communication mode (CM), and a multimode link count (MLC), wherein the ranking is specified by the Internet Protocol Version 6 (IPv6) Low Power Lossless Routing Protocol; And a processor configured to execute a plurality of steps of the computer-executable program, wherein the steps include: exploring the D-routes of all data nodes using the IPv6 Low Power Loss Routing Protocol to form the DODAG topology, wherein the IPv6 Low Power Loss Routing Protocol uses a DODAG Information Object (DIO) message for an upward route exploration procedure and a Destination Advertisement Object (DAO) message for a downward route exploration procedure; exploring a plurality of neighboring nodes while exploring the D-routes, wherein when the processor receives a broadcast DIO message from another node via the transceiver, the processor considers that other node as one of the neighboring nodes; and using the transceiver to transmit the Accumulated Traffic Load (ATL) and the identification codes of the neighboring nodes to a data concentrator via the DAO message; wherein the DIO message carries parameters specified by the IPv6 Low Power Loss Routing Protocol, as well as other parameters, to select a parent (a route) in the DODAG topology. The DAO message carries the parameters specified by the IPv6 Low Power Lossy Network Routing Protocol and the Accumulated Traffic Load (ATL), the identification codes of the adjacent nodes, and the communication mode (CM) of the node device. The ATL of a data node n includes the data node n's own traffic load and the accumulated child node traffic load. The ATL of the data node n is calculated as follows: where LD(n) is the data node n's own traffic load, is the number of child nodes of the data node n, and (k=1, 2, ...,) are the child nodes of the data node n.

4. The node device as described in claim 1, wherein when the node device has the general data and the priority data, the node device transmits the priority data first.

5. A node device for a multi-hop heterogeneous wireless network including a multi-mode concentrator, the node device comprising: A transceiver is configured to send a Destination-Directed Acyclic Graph (DODAG) Information Object (DIO) message to initiate a general data route exploration and form a DODAG topology based on the explored multiple general data routes (D-routes). The transceiver is further configured to receive a Destination Advertisement Object (DAO) message to set multiple downward general data routes and obtain an Accumulated Traffic Load (ATL) and neighbor information of multiple data nodes to perform a best-priority route exploration to construct an optimal routing topology. The transceiver is configured to transmit the optimal routing topology to multiple data nodes on the explored multiple priority routes (P-routes) to transmit priority data to the multimode concentrator. The transceiver is configured to receive general data in the DODAG topology and priority data in the optimal routing topology. A memory is configured to store a plurality of computer-executable programs and a plurality of parameters, including a communication mode (CM), an accumulated traffic load (ATL), a neighbor set, a route overlap (DRO), and a best priority route. And a processor configured to execute a plurality of steps of the computer-executable program, wherein the steps include: exploring general data routes (D-routes) for all the data nodes using Internet Protocol Version 6 (IPv6) Low Power Loss Routing Protocol, wherein the IPv6 Low Power Loss Routing Protocol uses DIO messages to perform an upward route exploration procedure and uses DAO messages to perform a downward route exploration procedure; exploring the optimal priority route by formulating a priority route exploration problem as a first nonlinear optimization problem to minimize route overlap calculated using the DRO, wherein the explored optimal priority route is further optimized to minimize route transmission time and route length.

6. The node device as described in claim 5, wherein the best-priority route exploration includes: The method employs a noncyclic route exploration approach to identify complex noncyclic routes for each priority data node in the multi-hop heterogeneous wireless network, exploring such noncyclic routes for each priority data node; it uses a minimum P-route overlap exploration method to solve a first nonlinear optimization problem to explore a first minimum overlapping P-route set in the multi-hop heterogeneous wireless network; it solves a second nonlinear optimization problem to explore a second minimum overlapping P-route set that minimizes the total route transmission time in the multi-hop heterogeneous wireless network; and it solves a third nonlinear optimization problem to explore a third minimum overlapping P-route set that minimizes the total route length in the multi-hop heterogeneous wireless network.

7. The node device as described in claim 6, wherein, In this multi-hop heterogeneous wireless network, the P-route from a priority node to a concentrator C →→→ … →C is represented as , and for a plurality of such priority nodes and concentrator C, one of the routes from the priority node to the concentrator C = (, , , …, , ) is acyclic if and if the following conditions are satisfied:

1.

2. , , …, 3. Adjacent to, ..., 4. The data concentrator C is adjacent to, and 5. Only adjacent to the concentrator C.

8. The node device as described in claim 7, wherein for the route from the priority node to the concentrator C = (, , , …, , ), the nodes are referred to as multiple forwarding nodes of the route because they transmit or forward data during priority data transmission.

9. The node device as claimed in claim 6, wherein the acyclic route exploration method comprises: constructing a single-hop acyclic route for a priority node adjacent to the multi-mode concentrator; and recursively extending and extending sub-routes, starting from a priority node not adjacent to the multi-mode concentrator, using a recursive extension and extension method to explore the acyclic routes for the priority node not adjacent to the multi-mode concentrator, wherein the sub-routes are part of a route to the multi-mode concentrator.

10. The node device as claimed in claim 9, wherein the recursive extension and extension method comprises: establishing a single-hop sub-route from the preferred node that is not adjacent to the multimode concentrator to each adjacent node; and recursively extending and extending each single-hop sub-route until the sub-route reaches the multimode concentrator, or deleting the sub-route when the sub-route cannot be extended without loops, or extending the sub-route when the sub-route can be extended to a plurality of extendable nodes.

11. The node device as claimed in claim 6, wherein the first minimum overlapping P-route set is a non-cyclic route set, and the routes of each of the priority data nodes in the first minimum overlapping P-route set minimize the DRO index, the DRO index being defined as follows: where is the number of priority data nodes in the multi-hop heterogeneous wireless network, is the number of individual routes, is the number of individual route lengths, and is the total number of different forwarding nodes on such routes.

12. The node apparatus as described in claim 6, wherein the minimum P-route overlap exploration problem is formulated as the first nonlinear optimization problem to find routes for complex priority nodes, wherein the first nonlinear optimization problem is computed as the set of complex acyclic routes for the such priority nodes.

13. The node device as described in claim 6, wherein the route transmission time (RTT) of a route is calculated as where is the expected number of transmissions of node (), , , …, are the maximum transmission rates of the complex links [], [], ..., [].

14. The node device as described in claim 6, wherein the total route transmission time (RTT) of a plurality of minimum overlapping routes is defined as a set of identifiers representing such minimum overlapping routes, the identifiers of such minimum overlapping routes serving as one element for identifying such minimum overlapping routes.

15. The node device as claimed in claim 6, wherein the route exploration problem of minimizing the total route transmission time is formulated as the second nonlinear optimization problem to find the second set of minimum overlapping P-routes that minimizes the total route transmission time, the second nonlinear optimization problem being defined as a set of identifiers representing the minimum overlapping routes, the identifiers of the minimum overlapping routes serving as one element for identifying the minimum overlapping routes.

16. The node device as described in claim 6, wherein the total route length of the identified plurality of minimum overlapping routes is defined as follows.

17. The node device as claimed in claim 6, wherein the route exploration problem of minimizing the total route length is formulated as the third nonlinear optimization problem to find the third set of minimum overlapping P-routes that minimizes the total route length, the third nonlinear optimization problem being defined as a set of identifiers representing the minimum overlapping routes, the identifiers of the minimum overlapping routes serving as one element for identifying the minimum overlapping routes.

18. The node device as claimed in claim 5, wherein the multimode concentrator transmits the discovered best priority route to the data nodes on the priority route for transmitting the priority data, wherein a general data node on one of the priority routes uses the other to relay the priority data, and wherein a priority data node uses the other to transmit or relay the priority data.

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