LTE and IEEE 802.11p for vehicular networking: a performance evaluation

Zeeshan Hameed Mir 0 Fethi Filali 0 0 Qatar Mobility Innovations Center (QMIC), Qatar Science and Technology Park (QSTP) , PO Box 210531, Doha, Qatar Various wireless communication systems exist, which enable a wide range of applications and use cases in the vehicular environment. These applications can be grouped into three types, namely, road safety, traffic efficiency, and infotainment, each with its own set of functional and performance requirements. In pursuance of assisting drivers to travel safely and comfortably, several of these requirements have to be met simultaneously. While the coexistence of multiple radio access technologies brings immense opportunities towards meeting most of the vehicular networking application requirements, it is equally important and challenging to identify the strength and weaknesses of each technology and understand which technology is more suitable for the given networking scenario. In this paper, we evaluate two of the most viable communication standards, Institute of Electrical and Electronics Engineers (IEEE) 802.11p and long-term evolution (LTE) by 3rd Generation Partnership Project for vehicular networking. A detailed performance evaluation study of the standards is given for a variety of parameter settings such as beacon transmission frequency, vehicle density, and vehicle average speed. Both standards are compared in terms of delay, reliability, scalability, and mobility support in the context of various application requirements. Furthermore, through extensive simulation-based study, we validated the effectiveness of both standards to handle different application requirements and share insight for further research directions. The results indicate that IEEE 802.11p offers acceptable performance for sparse network topologies with limited mobility support. On the other hand, LTE meets most of the application requirements in terms of reliability, scalability, and mobility support; however, it is challenging to obtain stringent delay requirements in the presence of higher cellular network traffic load. 1. Introduction Many believe that the integration of information and communication technologies with transportation infrastructure and vehicle will revolutionize the way we travel today. The enabling technologies envisioned to realize the proposed framework would spur an array of applications and use cases in the domain of road safety, traffic efficiency, and infotainment. These applications allow dissemination and gathering of useful information among vehicles and between transportation infrastructure and vehicles in pursuance of assisting drivers to travel safely and comfortably. Reliable and low-latency communication between vehicles and transport infrastructure is critical to the implementation success of many of these applications. Vehicular networking is the enabling technology which allows the realization of the variety of applications and use cases. Given the significant potential to cater for diverse applications and their performance requirements, there has been a growing demand to equip vehicles with multiple connectivity modalities. In order to fully exploit these capabilities, vehicles are required to intelligently select the most appropriate technology for the specific networking scenarios. To this end, it is necessary to know the strengths and weaknesses of each technology and understand which technology would be more suitable. Among several communication modalities, in this paper, we choose to compare Institute of Electrical and Electronics Engineers (IEEE) 802.11p and long-term evolution (LTE) for various networking conditions, operating parameter settings, and application requirements. The IEEE 802.11p [1] is considered as the de facto standard to implement several of the vehicular networking applications. The standard includes Physical (PHY) and Medium Access Control (MAC) layer specification as well as upper-layer protocols. IEEE 802.11p is essentially an IEEE 802.11-based standard adapted for the wireless environment with vehicles. It inherits several of the characteristics like simplicity and distributed medium access control mechanism. Mostly, in-vehicle on-board units (OBUs) and roadside units (RSUs) fixed with transport infrastructure like traffic signals utilize this standard. Given the diverse performance requirements from a wide spectrum of vehicular networking applications, several advocate the feasibility of LTE standard by the 3rd Generation Partnership Project (3GPP) [2] as an emerging solution. To this end, we envision an advanced LTE-technology-enabled OBU. Alternatively, the smartphones with LTE connectivity can be leveraged to support a number of applications [3]. The main objective of this paper is to conduct a comparative study between IEEE 802.11p and LTE and evaluate their suitability to different vehicular networking applications. The novelty of our study lies in the exploration of the impact of variety of networking parameters settings such as beacon transmission frequency, vehicle densities, and average vehicle speed on the performance. Both standards are compared in terms of delay, reliability, scalability, and mobility support while accounting for different vehicular networking application requirements in the domain of road safety, travel efficiency, and infotainment. Additionally, we also include a summary of the IEEE 802.11p and LTE standards, an overview of the vehicular networking applications and their performance requirements, and a detailed discussion on the lessons learned and insight for future research directions. Moreover, the use of single simulation platform for modeling and evaluation makes this study useful for more realistic and applied systems. In order to clearly state the overall scope of the paper, we define the following research questions which are addressed in this paper: (1). How do different networking parameters such as beaconing frequency, vehicle density, and vehicle average speed affect the performance of IEEE 802.11p and LTE? (2). For what settings of parameter values that the performance of IEEE 802.11p and LTE degrades against a set of vehicular networking application requirements? (3). Does the performance in terms of delay, reliability, scalability, and mobility support degrade significantly or trivially with the change in different parameter values? (4). What types of applications would be supported by IEEE 802.11p and LTE? There are number of research studies which assess the feasibility of IEEE 802.11p and LTE standards to support vehicular networking applications. However, to the best of our knowledge, most of the previous studies only answer a subset of the above-mentioned questions or partially cover the topics presented in this paper. The comparison between two fundamentally differently designed standards (i.e., infrastructure-less vs. infrastructure-based) under various networking conditions and performance requirements reveals intere (...truncated)