## 2 Related Work  
Nowadays, the industrial field is becoming more intelligent, and the industrial Internet of things is also becoming more scaled, but there are still many incompatible protocols. Therefore, researchers are conducting in-depth studies on this issue. The study by [9] proposes an architecture for WIA-PA and WirelessHART which are connected to IPv6 Internet. In [10], the author integrates HTTP, MQTT, LoRaWAN and OPC UA into the Internet of things platform for intelligent power applications to solve the multi-application scenario problem. Reference [11] proposes a software architecture for data format conversion between different industrial protocols. Similarly, [PERSON]. [12] implements the industrial Internet of things based on MQTT and OPC UA. In addition, [PERSON]. [13] designs a prototype of an Internet of things gateway which bridges the traditional Modbus RTU equipment to MQTT. Although [9; 10; 11; 12; 13] extend traditional industrial networks to industrial Internet of things, they all depend on low-rate network protocols and cannot satisfy industrial control applications. In addition, researchers often combine Fieldbus and industrial Ethernet protocols with wireless technology to meet the requirement of a better quality of service (QoS). Before the maturity of 5G technology, industrial control protocols were mostly combined with mature wireless technologies. In this regard, [PERSON]. [14; 15] both propose a PROFIBUS industrial wireless gateway based on ZigBee technology. Moreover, [PERSON]. [16] designs an embedded gateway based on FPGA, which combines the 4G technology with the PROFIBUS-DP industrial protocol. Additionally, [PERSON]. [17] realizes the mutual communication between the EtherCAT protocol as well as IEEE 802.11/802.15.4 wireless standards. In Ref. [18], the fail-safe protocol in EtherCAT is implemented on IEEE 802.11. In another study, [PERSON]. [19] explores the possibility of interconnecting PROFINET with wireless standards such as IEEE 802.11 by a bridge or gateway. Furthermore, [PERSON]. [20] designs an industrial control system based on ZigBee technology to transmit data from multiple Modbus slave stations to the controller. Obviously, [PERSON]. [17; 18; 19; 20] interconnect industrial Ethernet with IWN. However, the speed and reliability are not comprehensively tested for in industrial control applications. With the rapid development of 5G technology, some researchers deeply integrate the time-sensitive network (TSN) technology with 5G in order to achieve low latency and high reliability in the industrial Internet. Among them, [PERSON]. [21] proposes a new uplink transmission method to provide TSN service for a 5G industrial Internet of things prototype system, while [22] builds a test platform for a TSN industrial control system based on 5G. Similarly, [23] proposes a technology for flow conversion between 5G and TSN, and evaluates it by industrial examples. References [21; 22; 23] combine 5G and TSN to meet more accurate time and data transmission requirements in industrial automation environments, and test network performance. However, the practical application of TSN is just beginning and there is still a long way to go before applying 5G-TSN in real factories. Some researchers have also evaluated and verified the 5G functions in industrial applications based on real situations. In particular, the industrial 5G test and development platforms are recognized by the 5G alliance for connected industries and automation (5G-ACIA). Moreover, Ref. [24] changes the physical layer structure of the industrial protocol to realize URLLC and tests it in a simulated factory environment. Further, Ref. [25] evaluates 5G prototype systems in an industrial environment that uses the PROFINET protocol. Reference [26] tests industrial and other vertical industries through the 5G test platform built in the UK. Similarly, Ref. [27] evaluates the 5G wireless performance in a real industrial production environment.