Special Issue on V2X Communications and Networks
As autonomous driving emerges as one of the challenges towards fifth (5G) generation mobile networks, vehicle-to-everything (V2X) communication attracts more attention recently. V2X includes several scenarios such as vehicle-to-vehicle (V2V), vehicle-to-infrastructure (V2I), vehicle-to-pedestrian (V2P) as well as vehicle-to-network (V2N). V2X is expected to bring new services: automated driving, road safety service, traffic efficiency service, and digitalization of logistics. V2X has been standardized in the IEEE 802.11p and 3GPP, and further discussed in 5G automotive association (AA).
Despite a number of initiatives, research works, and tests, there are still questions and concerns about how to provide reliable and scalable low latency connectivity, how to design secure and reliable systems, and how to develop applications for improved safety and cooperative driving. To answer these questions, in this special issue, we have solicited research papers that investigate all the protocol and service layers as well as communication systems in depth. Out of many submissions, we have selected five excellent papers in the area of communication systems for V2X and emerging services in V2X communications and networks.
The first section of this special issue includes three papers dealing with communication systems for V2X. The paper, ¡°Game-Based TDMA MAC Protocol for Vehicular Network¡± by Zhang Tianjiao and Zhu Qi suggests a new TDMA MAC protocol for vehicular ad hoc networks. In such systems, vehicles may encounter collisions, especially when many vehicles try to transmit simultaneously. To resolve this problem, the authors present a slot reservation algorithm based on game theory. The second paper in this category, ¡°Fast Packet Classification for V2X Services¡± by Wooguil Pak suggests a fast packet classification that runs with a huge number of policy rules for SDN/NFV 5G networks. The author presents a dynamic decision tree that classifies packets using recursive dynamic partitioning and is updated. The third paper in this category, ¡°Inter-Vehicle Cooperation Channel Estimation for IEEE802.11p V2I Communications¡± by Yan Yang, Dan Fei and Shuping Dang suggests an inter-vehicle cooperation channel estimation scheme for V2I channels. This scheme uses interpolation to acquire accurate channel state information and further validated with a scalable data transmission scheme for the physical layer.
The second section of this special issue includes two papers that are concerned with emerging services in V2X communications and networks. The paper ¡°Bus-Based Content Offloading for Vehicular Networks¡± by Zhe Wang, Zhangdui Zhong, Minming Ni, Miao Hu, and Chih-Yung Chang suggests the exploitation of bus to solve a vehicular content-offloading problem. The proposed bus-based content offloading (BBCO) algorithm formulates the mathematical model to estimate the number of encountering buses and the degree of urgency for each content request. Based on these estimates, the BBCO algorithm presents a resource allocation scheme to maximize the volume of offloaded content from bus to sedan, while it also provides an improved fairness of offloading opportunity. The other paper, ¡°Achieving Location Privacy through CAST in Location Based Services¡± by Ruchika Gupta and Udai Pratap Rao proposed a decentralized vehicular communication scheme for privacy-preserving location-based services. The proposed scheme employs series of trust among peers whose cached mobile data are used to collaborate with other peers to get the location service locally. Since the scheme removes the trusted third party which is susceptible to privacy attack, location privacy of users is preserved in the presence of a malicious or compromised third party with low latency.