A time delay guarantee method for clouded PLC service under a 5G-TSN architecture

Abstract

This invention relates to a latency guarantee method for cloud-based PLC services under a 5G-TSN architecture. It adds service priority mapping, priority queue management, and wireless resource scheduling functions to the 5G-TSN network. The wireless resource priority allocation method for cloud-based PLC industrial control services includes statistical queue data volume, feedback of wireless channel quality, calculation of required wireless resources, and allocation of wireless resources. This reduces 5G network latency, minimizes intermediate cables and equipment, expands the mobile range of equipment terminals, and ensures priority resource allocation for cloud-based PLC services over the wireless interface. In multi-service mixed transmission scenarios, the proposed algorithm achieves lower latency than algorithms without guarantees. The virtual communication interface can flexibly connect with multiple protocols, supports interconnection of devices from multiple manufacturers, enables cloud-based collaborative control, improves production efficiency, and allows the 5G-TSN network to simultaneously carry multiple services while providing latency deterministic guarantees for industrial control services, reducing the deployment complexity of industrial field networks.

Description

Technical Field

[0001] This invention relates to the field of 5G and industrial internet synergy and integration technology, and in particular to a latency guarantee method for cloud-based PLC services under a 5G-TSN architecture. Background Technology

[0002] The synergy and integration of 5G and the Industrial Internet has become a hot topic in current academic research. 5G has low latency and high reliability connectivity, and its application in industry is a common need for the communications and industrial sectors. However, industrial services have extremely stringent requirements for the performance of the bearer network. The factory bearer network not only needs to have low latency, low jitter, and high reliability, but also deterministic characteristics. For industrial control systems, deterministic latency guarantees are the foundation for system security and controllability. Therefore, how to achieve coordinated transmission between 5G and TSN to improve the deterministic bearing capacity of the 5G system has become a key technical issue for the deep empowerment of core industrial processes by 5G.

[0003] Time-Sensitive Networking (TSN) is a series of standards and specifications developed by the IEEE 802.1 working group based on standard Ethernet, enhancing Layer 2 technologies such as time synchronization, resource management, traffic shaping, and network configuration. Technically, TSN offers deterministic latency guarantees and unified multi-service carrying capabilities. By achieving high-precision time synchronization among nodes within the TSN domain, it not only ensures bounded end-to-end transmission latency and jitter for time-triggered services with strong real-time requirements but also enables "one-network transmission" for non-real-time and best-effort services. At the networking level, TSN, being compatible with standard Ethernet protocols, can collaborate with heterogeneous industrial field communication protocols, achieving forward compatibility with the coexistence of heterogeneous field communication protocols. However, with the deployment of numerous sensors in equipment, workshops, and factories, and the widespread use of intelligent terminals such as robotic arms and mobile robots on production lines, wired TSN networks struggle to meet the access and data transmission needs of smart factory terminals. The integration and collaboration of 5G and TSN is not only a requirement for the extension of 5G into the industrial field but also a driving force behind the inherent needs of smart factories.

[0004] Currently, the IT and OT fields have proposed the concept of cloud-based PLCs, which are programmable controllers running in the cloud. By standardizing IoT interfaces and cloudifying applications, software-defined PLCs can directly communicate with industrial internet platforms, enabling remote control of cloud-based PLCs. The emergence of cloud-based PLCs makes PLC deployment more flexible, enabling functions such as rapid creation, flexible migration, and secure backup of industrial control tasks. On the one hand, cloud-based PLCs can be deployed on MEC servers in industrial parks, achieving data offloading for industrial control business at 5G UPF, and providing industrial control services to factories based on the powerful computing power of MEC. On the other hand, cloud-based PLCs can further penetrate 5G networks, pushing edge computing capabilities down to 5G CUs, in general... Based on the 5GCU protocol stack implemented on the architecture server, a traffic offloading function is integrated, and a cloud-based PLC is deployed. Industrial control business data is offloaded in the 5GCU, further shortening the communication link between the cloud-based PLC and the controlled equipment in the industrial field. However, how to ensure the industrial control business data of the cloud-based PLC? In the entire 5G-TSN network, the 5G air interface has the greatest impact on the determinism of data transmission. Due to the scarcity of 5G air interface resources, how to provide reliable latency guarantee for industrial control business under multi-service bearing conditions has become the key to carrying cloud-based PLC business under the 5G-TSN architecture. How to reliably transmit in the 5G-TSN network has become the main problem faced by cloud-based PLC devices based on 5G-TSN. Summary of the Invention

[0005] This invention provides a latency guarantee method for cloud-based PLC services under a 5G-TSN architecture. It reduces 5G network latency, decreases intermediate cables and equipment, expands the mobility range of equipment terminals, and ensures that cloud-based PLC services receive priority resource allocation in the wireless air interface. In multi-service mixed transmission scenarios, the proposed algorithm achieves lower latency than algorithms that do not provide guarantees. The 5G-TSN network can simultaneously carry multiple services and provides latency deterministic guarantees for industrial control services, thereby reducing the deployment complexity of industrial field networks.

[0006] To achieve the above objectives, the present invention employs the following technical solution:

[0007] A latency guarantee method for cloud-based PLC services under a 5G-TSN architecture includes the following:

[0008] 1) Set up a service priority mapping function module in the 5G-TSN network: When different service flows arrive at the base station, the base station first identifies the different service flows according to the flow ID and maps the different service flows to different queues according to their priorities;

[0009] 2) Set up a priority queue management module in the 5G-TSN network: Queue according to the latency requirements of industrial control service flows. The smaller the latency requirement, the higher the data packet is in the queue. Among industrial control service flows with different scan cycles and different latency requirements, industrial control service flows with scan cycles from small to large and latency requirements from high to low are given priority sorting. For other priority queues, FIFO rules are used for queuing.

[0010] 3) In the 5G-TSN network, a wireless resource scheduling function module is set up. The method for prioritizing the allocation of wireless resources for cloud-based PLC industrial control services includes the following steps:

[0011] (1) Statistical queue data volume: The current queue contains n cloud-based PLC industrial control business flows, and the number of data packets corresponding to the same type of industrial control business flow i is... By counting the number of data packets to determine the amount of data in the queue, we can obtain the number of data packets. ;

[0012] (2) Feedback on wireless channel quality: The wireless channel quality indicator corresponding to industrial control service flow i is as follows: Based on the adaptive modulation and coding rules, the number of bits that each resource block can carry under this wireless channel quality is: , More feedback indicates better wireless channel quality.

[0013] (3) Calculate the required wireless resources: Based on the wireless channel quality of different cloud-based PLC industrial control service flows, obtain the required bearer resources. Number of RBs required per data packet ,in, Given the length of the data packets, we can obtain the number of radio resources required to transmit the m data packets currently in the queue. ;

[0014] (4) Allocating radio resources: When allocating radio resources over the air interface, the highest priority queue is allocated first. The total number of radio resources that can be allocated within the Transmission Time Interval (TTI) is... :

[0015] when If all data packets in the queue are allocated to the corresponding radio resources, then radio resources will be allocated to other queues only after all data packets in the highest priority queue have been allocated resources.

[0016] like Then, the remaining time values ​​of different data packets will be compared and allocated accordingly. ,in, This is the latency requirement value for this data packet. The remaining time is the time that the data packet has been waiting for, calculated based on the remaining time of all data packets in the highest priority queue. Resource allocation, remaining time value The smaller the value, the higher the priority for resource allocation, until all current wireless resources have been allocated.

[0017] Furthermore, the 5G-TSN architecture for cloud-based PLC services includes cloud-based PLC, video services, other data services, and a 5G-TSN network. The cloud-based PLC, video services, and other data services are transmitted from the server to the client via the 5G-TSN network.

[0018] Furthermore, the 5G-TSN network includes a network-side TSN converter NW-TT, a user plane function UPF, service priority mapping, priority queue management, radio resource scheduling, user terminal UE, and a device-side TSN converter. Cloud-based PLCs, video services, and other data services access the 5G core network via the user plane function UPF and the network-side TSN converter NW-TT. Service priority mapping, priority queue management, and radio resource scheduling transmit the allocated resources to the user terminal UE. The user terminal UE connects to the device-side TSN converter, providing a TSN egress port.

[0019] Furthermore, when allocating wireless resources, different service flows are tagged with priority labels. Priority labels with values ​​of 0 and 1 are high priority, priority labels with values ​​of 2, 3, or 4 are medium priority, and priority labels with values ​​of 5, 6, or 7 are low priority.

[0020] Furthermore, in the allocation of wireless resources, for queues with the same priority, when service flow data of the same priority arrives, they are queued according to the latency requirements of the service flow with the same priority. The smaller the latency requirement value, the earlier the data packet of that service flow is placed.

[0021] Compared with the prior art, the beneficial effects of the present invention are:

[0022] 1) Reducing 5G network latency reduces intermediate cables and equipment, thus expanding the mobile range of device terminals;

[0023] 2) Cloud-based PLC services receive priority resource allocation in the wireless air interface. In multi-service mixed transmission scenarios, the proposed algorithm can achieve lower latency than algorithms that do not provide guarantees.

[0024] 3) The 5G-TSN network can carry multiple services simultaneously and provide latency deterministic guarantees for industrial control services, reducing the deployment complexity of industrial field networks. Attached Figure Description

[0025] Figure 1 This is the 5G-TSN architecture diagram for cloud-based PLC services as described in this invention.

[0026] Figure 2 This is a flowchart illustrating the allocation of radio resources by a base station for different service flows under the 5G-TSN architecture described in this invention.

[0027] Figure 3 This is a time delay diagram of the method provided by this invention and other non-guaranteed methods for Yunhua PLC services. Detailed Implementation

[0028] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings:

[0029] See Figure 1 This is a 5G-TSN architecture diagram for cloud-based PLC services according to the present invention. The present invention provides a latency guarantee method for cloud-based PLC services under a 5G-TSN architecture. The 5G-TSN architecture for cloud-based PLC services includes cloud-based PLC, video services, other data services, and a 5G-TSN network. The 5G-TSN network includes a network-side TSN converter (NW-TT), a user plane function (UPF), service priority mapping, priority queue management, radio resource scheduling, user terminals (UEs), and a device-side TSN converter. There are multiple different user terminals in the network, each carrying different service types. Cloud-based PLC, video services, and other data services access the 5G core network via the user plane function (UPF) and the network-side TSN converter (NW-TT). Service priority mapping, priority queue management, and radio resource scheduling transmit the allocated resources to the user terminals (UEs). The user terminals (UEs) are connected to the device-side TSN converters, providing TSN egress ports.

[0030] This invention provides a latency guarantee method for cloud-based PLC services under a 5G-TSN architecture, comprising the following:

[0031] 1) Set up a service priority mapping function module in the 5G-TSN network: Different service flows have different flow IDs to distinguish different services. When different service flows arrive at the base station, the base station first identifies the different service flows according to the flow ID and maps the different service flows to different queues according to their priorities. For example, the industrial control service flow belonging to the cloud PLC is mapped to priority queue Q0, video services and other mobile service flows with real-time requirements are mapped to priority queue Q1, and other service flows without latency requirements are mapped to priority queue Q7. Among them, queue Q0 is the highest priority queue, and so on. Queue Q7 is the lowest priority queue. The higher the service priority, the smaller its corresponding priority queue number.

[0032] 2) Configure a priority queue management module in the 5G-TSN network: Queuing is performed based on the latency requirements of industrial control service flows. The lower the latency requirement, the higher the data packet is placed in the queue. Among industrial control service flows with different scan periods and different latency requirements, those with scan periods from small to large and latency requirements from high to low are prioritized. For other priority queues, FIFO (First In First Out) queuing is used. For queue Q0, data will no longer be queued using FIFO, but will be queued according to the latency requirements of industrial control service flow i. To queue, that is The smaller the value, the higher the data packet should be in the queue;

[0033] 3) A wireless resource scheduling module is set up in the 5G-TSN network to ensure latency for cloud-based PLC industrial control services. Priority is given to wireless resource scheduling for the high-priority queue Q0. Since wireless air interface scheduling is performed according to the Transmission Time Interval (TTI), which is typically 0.5ms or 1ms, wireless air interface resources need to be dynamically scheduled every TTI to meet the transmission requirements of different services. The priority allocation method for wireless resources for cloud-based PLC industrial control services includes the following steps:

[0034] (1) Statistical queue data volume: When the number of cloud-based PLC industrial control business flows involved in the current queue Q0 is n, the number of data packets corresponding to the same type of industrial control business flow i is: By counting the number of data packets to determine the amount of data in the queue, we can obtain the number of data packets. ;

[0035] (2) Feedback on wireless channel quality: Since different cloud-based PLC industrial control service flows are carried by different wireless terminals, when the wireless channel quality indicator corresponding to industrial control service flow i is... At that time, according to the adaptive modulation and coding rules, the number of bits that each resource block can carry under this wireless channel quality is obtained as follows: , More feedback indicates better wireless channel quality.

[0036] (3) Calculate the required wireless resources: Based on the wireless channel quality of different cloud-based PLC industrial control service flows, obtain the bearer... The number of RBs required for each data packet is ,in, Let m be the length of the data packet. Therefore, the radio resources required to transmit the m data packets in the current queue are: ;

[0037] (4) Allocating wireless resources: The wireless resource guarantee process for high-priority industrial control services such as cloud-based PLCs is as follows: Figure 2 As shown,

[0038] Step 1: After passing through the User Plane Function (UPF) in the 5G core network, the service data enters the wireless base station side. In order to process different services differently at the air interface, priority labels (PCs) are assigned to different service flows based on the characteristics of the service flow. PC values ​​of 0 and 1 indicate high priority, PC values ​​between 2 and 4 indicate medium priority, and PC values ​​between 5 and 7 indicate low priority.

[0039] Step 2: After the service flow is marked, it enters the base station side. First, it goes through service priority mapping. After passing through the network-side TSN converter NW-TT, different services will be marked with service priority identifiers. According to the different service priority identifiers, different service flows will be mapped to different queues on the base station side. The higher the queue number, the lower its priority. For high priority queues, when service flow data of the same priority arrives, it does not follow the first-in-first-out (FIFO) rule. Instead, it is queued according to the latency requirements of service flows of the same priority. The smaller the latency requirement value, the more likely the data packet of that service flow should be placed at the front. This ensures that even if resources cannot fully guarantee the transmission of high priority queues, the most urgent service flows can still be transmitted.

[0040] Step 3: When allocating radio resources over the air interface, queue Q0 will be allocated first. Since queue Q0 uses a queuing mechanism based on service latency requirements, data packets with higher latency requirements will be allocated resources earlier. Assume the total number of radio resources that can be allocated in the current transmission time interval (TTI) is... ;

[0041] Step 3.1, when If all data packets in the queue are allocated to the corresponding radio resources, and the number of radio resources meets the data packet transmission requirements of the high-priority queue Q0, then after allocating resources to the high-priority queue, resources are allocated to the medium-priority and low-priority queues.

[0042] Step 3.2, if Then, the remaining time values ​​of different data packets will be compared and allocated accordingly. ,in, This is the latency requirement value for this data packet. This is the time value that the data packet has been waiting for. This includes transmission time, latency, and processing time in the non-air interface portion, calculated based on the remaining time of all data packets in queue Q0. Resource allocation, remaining time value The smaller the value, the more priority will be given to resource allocation until all available wireless resources within the current transmission time interval TT have been allocated.

[0043] With this resource allocation method, the higher the time urgency of the same type of industrial control business flow, the earlier it can obtain wireless air interface resource allocation, which can ensure that cloud-based PLC industrial control business can obtain timely transmission.

[0044] See Figure 3 Compared with the polling scheduling mechanism, the latency guarantee method for PLC services proposed in this invention provides timely wireless resource guarantees for PLC services. Therefore, even as the number of service streams increases, the latency of cloud-based PLC services does not fluctuate, demonstrating the latency determinism of the proposed method. In contrast, the latency of the polling scheduling mechanism increases with the number of service streams and cannot provide quality of service guarantees for cloud-based PLCs under multi-service transmission conditions.

[0045] The above embodiments are implemented based on the technical solution of the present invention, providing detailed implementation methods and specific operation processes. However, the scope of protection of the present invention is not limited to the above embodiments. Unless otherwise specified, the methods used in the above embodiments are conventional methods.

Claims

1. A latency guarantee method for cloud-based PLC services under a 5G-TSN architecture, characterized in that, Includes the following: 1) Set up a service priority mapping function module in the 5G-TSN network: When different service flows arrive at the base station, the base station first identifies the different service flows according to the flow ID and maps the different service flows to different queues according to their priorities; 2) Set up a priority queue management module in the 5G-TSN network: Queue according to the latency requirements of industrial control service flows. The smaller the latency requirement, the higher the data packet is in the queue. Among industrial control service flows with different scan cycles and different latency requirements, industrial control service flows with scan cycles from small to large and latency requirements from high to low are given priority sorting. For other priority queues, FIFO rules are used for queuing. 3) In the 5G-TSN network, a wireless resource scheduling function module is set up. The method for prioritizing the allocation of wireless resources for cloud-based PLC industrial control services includes the following steps: (1) Statistical queue data volume: The current queue contains n cloud-based PLC industrial control business flows, and the number of data packets corresponding to the same type of industrial control business flow i is... The number of data packets is used to count the amount of data in the queue. ; (2) Feedback on wireless channel quality: The wireless channel quality indicator corresponding to industrial control service flow i is as follows: Based on the adaptive modulation and coding rules, the number of bits that each resource block can carry under this wireless channel quality is: , More feedback indicates better wireless channel quality. (3) Calculate the required wireless resources: Based on the wireless channel quality of different cloud-based PLC industrial control service flows, obtain the required bearer resources. Number of RBs required per data packet ,in, Given the length of the data packets, we can obtain the number of radio resources required to transmit the m data packets currently in the queue. ; (4) Allocating radio resources: When allocating radio resources over the air interface, the highest priority queue is allocated first. The total number of radio resources that can be allocated within the Transmission Time Interval (TTI) is... : when If all data packets in the queue are allocated to the corresponding radio resources, then radio resources will be allocated to other queues only after all data packets in the highest priority queue have been allocated resources. like Then, the remaining time values ​​of different data packets will be compared and allocated accordingly. ,in, This is the latency requirement value for this data packet. The remaining time is the time that the data packet has been waiting for, calculated based on the remaining time of all data packets in the highest priority queue. Resource allocation, remaining time value The smaller the value, the higher the priority for resource allocation, until all current wireless resources have been allocated.

2. The latency guarantee method for cloud-based PLC services under a 5G-TSN architecture according to claim 1, characterized in that, The 5G-TSN architecture for cloud-based PLC services includes cloud-based PLC, video services, other data services, and a 5G-TSN network. The cloud-based PLC, video services, and other data services are transmitted from the server to the client via the 5G-TSN network.

3. The latency guarantee method for cloud-based PLC services under a 5G-TSN architecture according to claim 1, characterized in that, The 5G-TSN network includes a network-side TSN converter NW-TT, a user plane function UPF, service priority mapping, priority queue management, radio resource scheduling, user terminal UE, and a device-side TSN converter. Cloud-based PLCs, video services, and other data services access the 5G core network through the user plane function UPF and the network-side TSN converter NW-TT. Service priority mapping, priority queue management, and radio resource scheduling transmit the allocated resources to the user terminal UE. The user terminal UE connects to the device-side TSN converter, providing a TSN egress port.

4. The latency guarantee method for cloud-based PLC services under a 5G-TSN architecture according to claim 1, characterized in that, When allocating wireless resources, different service flows are tagged with priority labels. Priority labels with values ​​of 0 and 1 are high priority, priority labels with values ​​of 2, 3, or 4 are medium priority, and priority labels with values ​​of 5, 6, or 7 are low priority.

5. A latency guarantee method for cloud-based PLC services under a 5G-TSN architecture as described in claim 1, characterized in that, In the allocation of wireless resources, for queues with the same priority, when service flow data of the same priority arrives, they are queued according to the latency requirements of the service flow of the same priority. The smaller the latency requirement value, the earlier the data packet of the service flow is queued.

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