Distributed industrial wireless network deterministic transmission scheduling system

Abstract

The application discloses a distributed industrial wireless network deterministic transmission scheduling system, which comprises the following modules: a synchronization module for time slot synchronization between nodes; a data transmission module for data transmission between nodes; and a node management module for node deletion and addition management. The application uses distributed negotiation scheduling design, reduces overall energy consumption and delay of the network, and avoids network paralysis caused by failure of a central control node.

Description

Technical Field

[0001] This invention belongs to the field of industrial wireless network transmission scheduling technology, specifically relating to a deterministic transmission scheduling system for distributed industrial wireless networks based on Glossy synchronous transmission. Background Technology

[0002] Industrial wireless networks are an emerging form of Industrial Internet of Things (IIoT) implementation, utilizing wireless communication technology to network and transmit data from industrial field instruments and sensors. Traditional industrial wireless networks use a store-and-forward approach to deliver data hop-by-hop, requiring forwarding nodes to receive the entire data packet before forwarding it to the next hop. This strategy increases data packet transmission latency and introduces unpredictable forwarding delays and jitter. Synchronous transmission can mitigate the latency caused by the store-and-forward strategy. Forwarding nodes do not need to store the entire data packet but forward data as a byte stream or bit stream, thus significantly reducing multi-hop transmission latency. Most synchronous transmission networks use a centralized framework to schedule the transmission and reception between nodes. Centralized scheduling requires a central control node to manage all nodes in the network. The complexity of the management process increases latency and energy consumption, and a failure of the central control node can cause the entire network to collapse. Summary of the Invention

[0003] This invention addresses the shortcomings of existing centralized technologies by proposing a distributed traffic negotiation transmission scheduling technology based on synchronous transmission. This eliminates single-point-of-failure problems, ensures a high packet delivery rate, reduces energy consumption and latency issues caused by excessive network uptime, and effectively solves key problems in industrial wireless networks.

[0004] The objective of this invention is achieved through the following specific technical solutions:

[0005] A distributed industrial wireless network deterministic transmission scheduling system, comprising the following modules:

[0006] The synchronization module is used for time slot synchronization between nodes.

[0007] The data transmission module is used for data transmission between nodes in a network with multiple data transmission time slots.

[0008] The node management module is used for managing the deletion and addition of nodes.

[0009] Preferably, the synchronization module ensures that the offset between data transmission time slots is less than 50µs, thereby ensuring the normal operation of Glossy synchronous transmission.

[0010] Preferably, the data transmission module can be divided into two sub-modules: a sending module and a receiving module.

[0011] The sending module operates on a single data transmission time slot, ensuring only one data packet sender per slot to prevent conflicts between nodes and thus reduce packet delivery rates. During the data transmission time slot, the sender enables Glossy flooding, allowing the sending module to distribute data packets across the entire network.

[0012] The receiving module allows nodes to enter receive mode when they are not the sender in a data transmission time slot, waiting for the sender's data packets to arrive.

[0013] A further preferred embodiment of the sending module is as follows:

[0014] In an industrial wireless network, the number of nodes is n, and the number of nodes is N. i It has variable node numbers. And the number of data packets to be transmitted, num, where ID is counted from 1 to n, and the largest node number in the current round of the network is ID. max ASN is the absolute timeslot frame number of the network, R i S is the number of rounds. i This refers to the i-th time slot in a certain round.

[0015] The sending module ensures determinism in data transmission through the following traffic negotiation steps:

[0016] The first step is to enter the Sth round of the first round of R1 transmission scheduling. i In each time slot, if the node ID of the node is equal to S i If a node selects the current time slot as its transmission time slot and initiates Glossy, other nodes will receive data packets in that time slot. For example, a node with ID 1 will send packets in the first time slot.

[0017] The second step is to determine the current number of data packets before sending them. If only one data packet remains to be sent, the counter D on the data packet is incremented by one, and the ID is set to 0 after the data packet is sent. During this period, the node remains in the receiving state. Otherwise, D remains unchanged.

[0018] The third step is to update the number of data packets to be sent after the node has finished sending the data packets, and check the counter D. If D is a non-zero constant, then change the current node ID to... .

[0019] Fourth step, if the current node is the largest node ID max If this node has only one data packet to send, then the largest node number piggybacked onto this data packet for the next round is... And then proceed to the next transmission time slot.

[0020] Step 5: If the maximum node number ID in the current round is... maxIt is 1 and this node has only one data packet to send, or the maximum node number ID. max If the value is equal to D, then the data packet transmission for this cycle ends after the data packet of the largest node has been sent.

[0021] Preferably, the node management module is as follows:

[0022] Network contention time slots are used to manage nodes. The number of contention time slots is fixed at two. If multiple nodes send packets in the same contention time slot, the node with the highest sending power will successfully send the packet. If the current node fails to send the packet, it will send the packet in the next contention time slot.

[0023] Joining Management: If a new node wants to join the network, it initiates a G lossy flood to send a request data packet during the contention slot, and other nodes in the network set their node number to n+1 after receiving this data packet.

[0024] Deletion Management: If a node N in the current network... i If no packets are sent within three consecutive time slots belonging to itself, then its management node N i+1 During the contention slot, a packet is sent to notify all nodes N in the network. i A fault occurred; the node number is greater than N. i The node update node number is .

[0025] The beneficial effects of this invention are:

[0026] This invention employs a traffic negotiation method to ensure deterministic packet transmission scheduling, and uses synchronous transmission to guarantee the reliability of all data packets in the industrial wireless network. Simultaneously, the network adapts to contention-based time slots by handling node additions and deletions to accommodate dynamic networks. This invention utilizes a distributed negotiation scheduling design, reducing overall network energy consumption and latency, and avoiding network paralysis caused by central control node failures. Attached Figure Description

[0027] Figure 1 This is a flowchart of data transmission time slots.

[0028] Figure 2 This is a scheduling diagram for a network with a scale of 4.

[0029] Figure 3 This is a comparison chart of packet delivery rates between the present invention and the centralized synchronous transmission algorithm.

[0030] Figure 4 This is a comparison chart of the number of time slots used by the present invention and the centralized synchronous transmission algorithm. Detailed Implementation

[0031] The following specific examples illustrate the implementation of the present invention, and those skilled in the art can easily understand the technical effects of the present invention from the content disclosed in this specification.

[0032] like Figure 1-2 As shown, the specific implementation process of the distributed industrial wireless network deterministic transmission scheduling system in this embodiment is as follows:

[0033] The first step, in the sending module, is to establish a data flow model for the network, with n network nodes and N nodes. i Each node has a variable node ID and a number of data packets to be transmitted, num, where ID is counted from 1 to n, and the largest node ID in the current round of the network is ID. max ASN is the absolute timeslot frame number of the network, R i S is the number of rounds. i This refers to the i-th time slot in a certain round.

[0034] The second step involves nodes randomly joining the network after it is started. The first node to start initiates a Glossy flood, and the synchronization module performs time slot synchronization across the entire network.

[0035] The third step, in the sending module, involves entering the Sth stage of the first round of R1 transmission scheduling. i In each time slot, if the node ID of the node is equal to S i If a node selects the current time slot as its transmission time slot and initiates Glossy, other nodes will receive data packets in that time slot. For example, a node with ID 1 will send packets in the first time slot.

[0036] The fourth step is to determine the current number of data packets before sending them. If only one data packet remains to be sent, the counter D on the data packet is incremented by one, and the ID is set to 0 after the data packet is sent. During this period, the node remains in the receiving state. Otherwise, D remains unchanged.

[0037] Step 5: After the node completes sending the data packets, update the number of data packets to be sent and check the counter D. If D is a non-zero constant, change the current node ID to... .

[0038] Step 6: If the current node is the largest node ID max If this node has only one data packet to send, then the largest node number piggybacked onto this data packet for the next round is... And then enter the competition slot.

[0039] Step 7: If the maximum node number ID in the current round is... max It is 1 and this node has only one data packet to send, or the maximum node number ID. maxIf the value is equal to D, then the data packet transmission for this cycle ends after the data packet of the largest node has been sent.

[0040] Step 8: In the node management module, the number of contention slots is set to a fixed two. If multiple nodes send packets in the same contention slot, the node with the highest sending power will successfully send the packet. If the current node fails to send the packet, it will send the packet in the next contention slot. After the two contention slots are completed, the next round of packet transmission begins.

[0041] Step 9: If a new node wants to join the network, it initiates a G lossy flood to send a request packet during the contention slot. Other nodes in the network, upon receiving this packet, set their node number to their ID. max +1 and update ID max .

[0042] Step 10: If a node N in the current network... i If no packets are sent within three consecutive time slots belonging to itself, then its management node N i+1 During the contention slot, a packet is sent to notify all nodes N in the network. i A fault occurred; the node number is greater than N. i The node update node number is .

[0043] Figure 2 This is an example of transmission scheduling for a network of size 4. Nodes 1-4 send 3, 1, 4, and 2 packets in one cycle, with node numbers 1, 2, 3, and 4 respectively. In the first round, time slots are allocated according to node number. Node 2, with 1 packet, sets the counter D in the packet to 1. Nodes 3 and 4, after sending packets, detect D=1 and therefore set their node numbers to 2 and 3 respectively. Node 4 is the largest node in this round and piggybacks the largest node number (3) for the second round when sending packets. After four rounds of negotiation and scheduling, the network uses 10 data transmission time slots to transmit all 10 packets from the four nodes.

[0044] This invention compares and tests a distributed traffic negotiation transmission scheduling method based on Glossy with a centralized synchronous transmission scheduling method. The measured network and centralized packet delivery rates are as follows: Figure 3 As shown, the number of network time slots used is as follows Figure 4 As shown in the figure. The experimental data demonstrates that this invention ensures a better packet delivery rate than centralized synchronous transmission, uses fewer time slots resulting in lower energy consumption, and transmits data packets to the entire network faster, reducing network latency. Furthermore, nodes do not need to manage node distribution scheduling tables; the nodes themselves select time slots for scheduling based on node information, thus solving the problem of single points of failure in industrial wireless networks.

[0045] This invention discloses a deterministic transmission scheduling system for distributed industrial wireless networks based on Glossy synchronous transmission. It establishes a deterministic transmission scheduling model based on traffic negotiation, where nodes negotiate traffic through the number of data packets and a deletion counter. For each node in the industrial wireless network, a transmission time slot is selected based on node information. Glossy flooding is used to send data packets to the entire network, and contention-based time slots are used to manage the addition and deletion of network nodes. This invention employs a traffic negotiation method to make data packet transmission scheduling deterministic, and synchronous transmission ensures the reliability of all data packets in the industrial wireless network. Simultaneously, the network uses contention-based time slots to handle node addition and deletion to adapt to dynamic networks. This invention uses a distributed negotiation scheduling design, reducing overall network energy consumption and latency, and avoiding network paralysis caused by central control node failure.

Claims

1. A deterministic transmission scheduling system for distributed industrial wireless networks, characterized in that: Includes the following modules: The synchronization module is used for time slot synchronization between nodes; The data transmission module is used for data transmission between nodes; The node management module is used for managing the deletion and addition of nodes; The data transmission module is divided into a sending module and a receiving module: The sending module has only one data packet sender in a data transmission time slot. During the data transmission time slot, the sender enables Glossy flooding, and the sending module sends the data packet to the entire network. If the receiving module is not the sender in the data transmission time slot, it enters the receiving mode and waits for the sender's data packet to arrive. The sending module performs the following traffic negotiation steps: Step 1, Enter the first round The first transmission scheduling Each time slot, if the node number equal If this node selects the current time slot as the transmission time slot and initiates Glossy, other nodes will receive data packets in this time slot. The second step is to determine the number of data packets in the node before sending the data packets. If only one data packet remains to be sent, increment the counter D on the data packet and set the ID to 0 after the data packet is sent. The device remains in the receiving state throughout this cycle; otherwise, D remains unchanged. The third step is to update the number of data packets to be sent after the node has finished sending the data packets, and check the counter D. If D is a non-zero constant, then change the current node ID to... ; Fourth step, if the current node is the largest node If this node has only one data packet to send, then the largest node number piggybacked onto this data packet for the next round is... And then proceed to the next transmission time slot; Fifth step, if the maximum node number of the current round... It is 1 and this node has only one data packet to send, or the largest node number. If the value is equal to D, then the data packet transmission for this cycle ends after the data packet of the largest node has been sent.

2. The distributed industrial wireless network deterministic transmission scheduling system according to claim 1, characterized in that: The sending module is specifically as follows: In an industrial wireless network, the number of nodes is n, and the number of nodes is N. i Each node has a variable node ID and a number of data packets to be transmitted, num, where ID is counted from 1 to n. The largest node number in the current round of the network is... ASN is the absolute timeslot frame number of the network. For the number of rounds, This refers to the i-th time slot in a certain round.

3. The distributed industrial wireless network deterministic transmission scheduling system according to claim 1 or 2, characterized in that: The node management module is described in detail below: Network contention time slots are used to manage nodes. The number of contention time slots is set to a fixed two. If multiple nodes send packets in a contention time slot, the node with the highest sending power will send successfully. If the current node fails to send, it will send packets in the next contention time slot.

4. The deterministic transmission scheduling system for distributed industrial wireless networks according to claim 3, characterized in that: The node management module also has the following management functions: Joining Management: If a new node wants to join the network, it initiates a Glossy flood to send a request data packet during the contention time slot, and other nodes in the network set their node number to n+1 after receiving this data packet; Deletion Management: If a node N in the current network... i If no packets are sent within three consecutive time slots belonging to itself, then its management node N i+1 During the contention slot, a packet is sent to notify all nodes N in the network. i A fault occurred; the node number is greater than N. i The node update node number is .

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