# A Bibliometric Analysis and Visualization of In-Vehicle Communication Protocols
## 3 Results
### Current Status of In-Vehicle Communication Protocol
#### 3.1.2 Distribution of Organisations  
This study of institutional contributions to in-vehicle communication protocols indicates that a significant concentration comes from Chinese universities. Figure 2 shows both the absolute and relative publication outputs for the top institutions. For example, Xidian University has 85 publications, accounting for approximately 2.91% of the total dataset. The Beijing University of Posts and Telecommunications follows closely with 84 (2.88%), and Tongji University with 82 (2.81%). These institutions are well-known for their strong research profiles in vehicular networks, intelligent transportation, and embedded communication systems. With 77 publications, Hunan University is joined by Beihang University with 74 publications, demonstrating considerable output. The two focus on research on autonomous vehicles and more advanced communication protocols such as CAN, FlexRay, and Automotive Ethernet. This dual representation of publication volume and proportion allows for a fairer comparison across institutions of varying sizes and outputs, highlighting both volume and relative research emphasis.  
Intelligent transportation systems and modern vehicles require real-time responses and support for increased data throughput. All these features are catered for by CAN FD (Flexible Data-rate) [13]. This laterally improves the traditional CAN protocol by increasing payload size and data communication rate. Despite its growing significance, how CAN FD is cited in the literature and its bibliometric clusters suggest it is lacking in scrutinized scholarly research, especially regarding secure high-speed vehicular networks.  
In addition to that, TSN remains relatively unexplored in co-citation networks or thematic clusters, where bibliometric mapping shows most of its attention should be directed towards [14]. This is especially true considering TSN's potential to bridge the gap between old systems and modern automotive architectures. Because of this, Time-Sensitive Networking (TSN)--an IEEE standard designed for data streaming over Ethernet with deterministic latency, in contrast to TSN's focus on delivering data in a controlled fashion--has yet to explore its complete potential in autonomous and connected vehicles [15]. In addition to ADAS, V2X and infotainment systems also require highly accurate timing, making TSN vital for these applications.  
Figure 2: Distribution of publications across major research institutions on in-vehicle communication protocols (2018–2025). Both absolute values and percentage contributions are shown to allow balanced comparison across institutions.  
Further illustrating China's extensive contribution in this field are Beijing Jiaotong University (65) and Shanghai Jiao Tong University (61), which have specialized work in V2X (Vehicle-to-Everything) communications and cyber-physical systems for vehicles. Outside of China, the most remarkable achievement is from the South Korean college Soonchunhyang University, which has 51 publications, showing the growing interest and research in smart transportation in the region. Coming in last is Tsinghua University, the most noted research center in the world, with 50 publications. The concentration of research in East Asia precisely illustrates the region's dominance in intelligent mobility innovations and the growing global importance of research on in-vehicle communication protocols [16].