## 5 Conclusions  
### Discussion and Implications  
In this study, we conducted network analyses to explore the key technologies in SEPs optical networks. The empirical results revealed that transmission of digital information, wireless communication networks, transmission, and multiplex communication are the key technologies in optical networks. Relevant professional industries have noted the increase in data volume and the demand for transmission speed and have thus emphasized the strengthening of digital information transmission. The number of hyperscale datacenters is increasing worldwide. These datacenters mainly provide services such as cloud computing, social media, software or platform services, and content transmission. Modules in optical networks that are capable of rapidly processing large amounts of information are thus crucial in such datacenters. At present, 100 G single channel has become the norm in the market, and the recent research and development of 400 G single channel is also promising [31; 32].  
In terms of transmission and multiplex communication, optical multiplexing is a perennial research focus [33; 34]. Wavelengths used for optical multiplexing are specified in channel spacing grids issued by the International Organization for Standardization (ISO) and the International Telecommunication Union. This signifies that technologies in optical networks are highly valued by the ISO. In 2020, the European Telecommunications Standards Institute of the Industry Specification Group established the Fifth Generation Fixed Network (F5G) and proposed an industry prospect, Fiber to Everywhere, which defines the five work items, namely F5G use cases, landscape of F5G technology and  
Figure 3: Yearly changes in the key technologies in SEPs optical networks. Note: The cumulative number of SEPs denotes the accumulated number of SEPs each year.  
standards, definition of fixed network generations, architecture of F5G, and F5G quality of experience [35]. Accordingly, optical network technologies are gradually being standardized, and the competition between manufacturers of SEPs is becoming fiercer.  
In terms of theoretical contribution, research on optical networks have mostly focused on technical [5; 6; 7; 8] or market [1; 9] aspects rather than employing a macroscopic perspective to reveal technology distribution of optical networks and the development trends in their key fields. Additionally, few studies have explored the technology trends of optical networks from the perspective of SEPs. However, observing the technology distribution of optical networks from the aspect of SEPs has become increasingly relevant because such technologies are gradually being standardized. Therefore, we adopted SEPs as the research focus in expectation of addressing this research gap.  
Furthermore, we introduced a technical map for optical networks to provide relevant industries and universities with valuable information. We analyzed the focus of technology development in a technology network of SEPs and disseminated information on research and development resource allocation and talent cultivation to industries and universities, respectively. With the development of optical networks, relevant industries should recruit technical talent in key technical fields and also cooperate with academia to increase relevant research and further cultivate technicians. The results of this study revealed that transmission of digital information, wireless communication networks, transmission, and multiplex communication are they key fields in optical networks. Relevant industries and universities can cooperate to enhance the development of optical networks and advance the key technologies that contribute to industrial standards.