Vehicular Communications Using DSRC: Challenges, Enhancements, and Evolution

Abstract

Dedicated Short-Range Communications (DSRC) has been designed to support vehicular communications. In the U.S., DSRC operates in the 5.9 GHz licensed spectrum band. Its physical (PHY) and medium access control (MAC) layers, defined in the IEEE 802.11p standard, are based on the IEEE 802.11 family of Wi-Fi standards. Vehicular communication environments differ significantly from the sparse and low-velocity nomadic use cases of a typical Wi-Fi deployment. Thus, there are many challenges to adapt Wi-Fi technologies to support the unique requirements of vehicular communications such as achieving high and reliable performance in highly mobile, often densely populated, and frequently non-line-of-sight environments. The automotive and the communications industries, academia, and governments around the world have been devoting tremendous efforts to address these challenges, and significant achievements have been made. Remaining challenges can be addressed by the future versions of DSRC. In this paper, we investigate the current technologies used by DSRC to support vehicle safety communications, analyze existing and possible DSRC performance enhancements that can be realized in the near term, and provide a few initial thoughts on the DSRC evolution path.

Why is Internet of Autonomous Vehicles not as Plug and Play as We Think ? Lessons to Be Learnt From Present Internet and Future Directions

“…Any massively networked IoT based systems will rely on the efficient means of data communications, IAV is the same; different physical layer technologies have been studied for communication of the networked vehicles in close proximity to each other and other roadside units. The technologies studied include Dedicated Short Range Communications (DSRC) and Wireless Access in Vehicular Environments (WAVE) [23]- [25] for intercommunications and ZigBee, Bluetooth for intra communications between the sensors of AVs [26].…”

Spectrally efficient emission mask shaping for OFDM cognitive radios

“…This channelization allows the MAC upper layer to perform multi-channel operations [5] and allows safety and other applications to occupy separate channels in order to manage and reduce interference. The four strict SEMs aim to reduce the effect of ICI between these channels although Wu et al have shown that transmitters on adjacent service channels still cause inter-ICI in the safety channel, even when they satisfy the class C requirement [6]. Shaping the 802.11p spectrum in order to reduce leakage and thus ICI is therefore important.…”

Vehicular ad hoc Networks

“…The plots demonstrate that at higher densities, the performance tends towards an ALOHA-like performance. Adapted from [108] distances. The performance trends towards an ALOHA-like behavior, due to a lack of protection against simultaneous transmissions by nearby nodes.…”

“…The frame size is assumed to be 300 bytes. Adapted from [108] Last but not least, as highlighted in [13,14] and due to the periodic nature of CAM, most of the VANET traffic will be generated periodically as well: each vehicle will start its broadcast transmissions when switched on and, since then, it will keep the generation of messages with the same initial phase . This means also that if the transmissions by two nodes collide once, they are likely to collide again and again.…”

“…Meanwhile, our understanding of wireless communications has been advanced a lot: there are definitely several areas for further improving [108] DSRC by leveraging the recent wireless technology advances. In this chapter, we will discuss potential PHY and MAC layer improvements that can benefit future generations of DSRC.…”