Evaluation and Optimization of LTE-V2X Mode 4 under Aperiodic Messages of Variable Size

Abstract

Vehicular networks connect vehicles for improved road safety and efficiency with the assistance of wireless information exchange. Vehicular networks are based on the frequent broadcast of awareness messages referred to as CAM (Cooperative Awareness Messages) or BSM (Basic Safety Message) in the ETSI and SAE standards, respectively. Vehicular network technology mostly used nowadays is based on cellular networks (LTE-V2X, 5G NR-V2X). LTE-V2X is an evolution of the 3GPP standard for 4G/LTE that allows vehicles to exchange information with other vehicles, pedestrians, or fixed objects such as traffic lights in their surroundings without the requirement of any infrastructure support. Reliable transmission of this information is important in LTE-V2X technology to confirm safety on the roads and effectively manage traffic flow. Most of the available studies are based on simplified data traffic models that generate CAMs at periodic intervals and with a fixed message size. In reality, the size and interval between the messages are not fixed and different from the simplified model. There are a few studies based on the real CAM generation (also known as the Empirical CAM Model) that show the significant deviations in results found with an unrealistic simplified traffic model. The Empirical CAM Model generates aperiodic messages of various sizes which leads to certain inefficiencies that affect the performance of LTE-V2X. In this thesis, those inefficiencies due to the realistic CAM generation are addressed and some mechanisms are also proposed and analyzed to overcome those effects. The results obtained in this thesis could be used not only for a better configuration of LTE-V2X but also for future standardization of its evolution.

Popular Abstract

In recent years, we have seen a remarkable surge in two technologies: cell phones and self-driving cars. These self-driving cars, or "smart cars," are designed to operate with minimal human intervention by communicating with each other on the road. To better understand the importance of this technology and my research in improving it, let us delve into this fascinating world.
Imagine a world where cars can not only drive themselves but also talk to each other. This is not science fiction; it is the reality of today's rapidly advancing automobile industry. Smart cars have the potential to revolutionize our roads, making them safer and more efficient.
The key to smart cars' success lies in their ability to communicate with each other seamlessly. Picture a group of friends embarking on a road trip. To ensure a smooth journey, they need to share essential information, such as their speed, location, and destination. Shouting or using hand signals is not practical on the road, so they use advanced communication systems, similar to high-tech walkie-talkies. These systems allow them to chat via cell phone towers or directly, allowing for efficient information exchange.
However, there is a challenge lurking on the horizon. Sometimes, when the group ventures into remote areas without cell phone signal, communication becomes unreliable. Here is where my thesis comes into play. I have dedicated my research to improving how these smart vehicles communicate, regardless of their location or how congested the "communication channels" become. One fundamental aspect of my research is to ensure that critical messages, such as warnings about road obstacles or potential collisions, always reach their intended recipients. This is like giving these messages top priority on a communication channel. Just as you would want an emergency message to be heard clearly on a walkie-talkie, it is crucial that smart cars can reliably convey critical information to avoid accidents and keep everyone safe.
Imagine you are using a walkie-talkie with your friends, and the signal isn't perfect. There might be static, and parts of the conversation might get lost or garbled. We have worked on techniques to ensure that, even in less than ideal conditions, the main message gets through. It is similar to improving the clarity of your walkie-talkie conversation so that, despite some interference, you can still understand the essential points.
Another vital aspect of my research involves managing how these "communication channels" are used. Think of it as ensuring that your friends do not talk over each other, allowing you to hear each person's message clearly. We have developed methods to ensure that smart cars use these "channels" in an organized way, minimizing confusion, and enhancing the efficiency of communication. By addressing these challenges and implementing innovative solutions, my research aims to ensure that smart cars can always communicate effectively and safely, regardless of their location or the level of activity on their "communication channels." This, in turn, contributes to safer roads and more efficient traffic flow for everyone.
The potential benefits of smart car communication are enormous. Beyond convenience, it has the power to reduce accidents and save lives. Imagine a future where cars can alert each other to dangerous road conditions or imminent accidents, allowing for quick and coordinated responses to prevent tragedies. It is a future where traffic flows smoothly, with vehicles working together like a well-orchestrated symphony. Of course, there are challenges along the way. Like any technological advancement, smart car communication faces obstacles that must be overcome. Ensuring privacy and security in this interconnected world of vehicles is a priority. Additionally, making sure that all vehicles, regardless of their make or model, can communicate effectively is another challenge on the horizon.
However, these challenges also present opportunities for innovation and collaboration. Researchers, engineers, and automakers are working together to refine smart car communication systems, making them more secure, reliable, and accessible. As we navigate the road ahead, it is essential to recognize the potential of smart car communication in transforming our transportation landscape. It has the capacity to make our roads safer, more efficient and environmentally friendly. My research is just one small step in this exciting journey that aims to ensure that smart cars can communicate effectively and reliably, bringing us closer to a future where our vehicles work together for the greater good of all.
In closing, smart car communication isn't just about technology; it is about the promise of safer roads, improved traffic flow, and the potential to save lives. It is about vehicles becoming smarter, so we can all travel more efficiently and safely toward a brighter future.

• author: Rashid, Md Mamunur
• supervisor: Fredrik Tufvesson
• organization: Department of Electrical and Information Technology
• course: EITM02 20232
• year: 2023
• type: H2 - Master's Degree (Two Years)
• subject: Technology and Engineering
• keywords: LTE-V2X, aperiodic, variable size, CAM
• report number: LU/LTH-EIT 2023-959
• language: English
• id: 9142240
• date added to LUP: 2023-12-15 10:54:16
• date last changed: 2023-12-15 10:54:16