Connectivity is a key enabler upon which the benefits of CAV technology will be realized. It refers to the communication infrastructure that allows data to be transferred from and between the different elements that make up the CAV ecosystem. In CAV, V2X is the umbrella term that denotes the communication framework in which data from a variety of sources including vehicle sensors, vehicle telematic systems, roadside infrastructure, pedestrians and communication networks are transferred across the system.
DSRC is based on the IEEE 802.11p-based wireless standard and supports secure
communication between vehicles and the surrounding infrastructure without the involvement of the mobile communications infrastructure.
As introduced in Section 3, C-V2X is a 3GPP standard, for vehicle wireless communication technology that is implemented using the mobile 4G or 5G technology. The early specifications and service requirements were defined and implemented in 3GPP Release 14 and significant enhancements, especially higher demands on security and reliability, provided in 3GPP Releases 15 and 16.
As an example of C-V2X, this report primarily focuses on vehicle to mobile network technology (C-V2N). This uses the mobile network to provide services such as fleet management, logistics and infotainment as well as enabling improved driving safety and road traffic efficiency through Cooperative Intelligent Transport Systems (C-ITS) and Advanced Driver Assistance Systems (ADAS). DSRC is an alternative V2X technology.
For example, C-V2N connectivity enables the distribution of real-time road traffic signals and traffic situations to drivers in the form of GeoCasted messages (messages that are
disseminated with information regarding a target geographic area) from the LTE network to the SIM card placed in the modem of the vehicle’s communications system.
Connected and autonomous vehicle technology enable a range of services and societal
benefits as highlighted earlier. However, with these benefits come significant risks that must be mitigated against. For example, despite the elimination of driver error as a positive outcome, risks may exist from a myriad of factors, such as system errors, cyber attacks on safety systems, and the behavioural improprieties of both passengers and pedestrians.
In addition, sophisticated data processing and storage abilities of CAV systems also raise data privacy concerns, examples include tracking of user location from location data stored in vehicles, and unauthorised use of personal data synced from personal devices. Connection to external networks such as the mobile network and cloud infrastructures, which may be
necessary for vehicle cooperation on the roads, increases privacy risks as data can be accessed by attackers and retrieved if network vulnerabilities are successfully exploited56.
The privacy and cyber security risks introduced by utilizing LTE C-V2N as a connectivity technology in CAV technology is also introduced. The cyber security threat modelling and risk analysis, scoring and mitigation frameworks beginning with the dataflows from the SIM card
56 Hazel Si Min Lim, A. T. (2018) ‘Autonomous Vehicles for Smart and Sustainable Cities: An In-Depth Exploration of Privacy and Cybersecurity Implications’ Retrieved from MDPI: https://www.mdpi.com/1996- 1073/11/5/1062
interface inside the connected vehicle to the mobile LTE RAN and Core networks are discussed in the subsequent sections.
Figure 13: V2X communication systems architecture57
In Figure 13 above, the general architecture of a heterogenous V2X system uses DSRC, C- V2X and Wi-Fi technologies to enable communications between devices with a wide range of motion patterns including Vehicle-to-Vehicle, Vehicle-to-Pedestrian and Vehicle-to-Cloud. In this architecture, the LTE network provides vital connectivity to the cloud Application Server.
Figure 14: End-to-end reference architecture of LTE V2C communications (Cisco)
Figure 14 provides an end-to-end high-level reference architecture of a Vehicle to Cloud communications systems enabled by the LTE mobile infrastructure. The high-level system components, from the vehicle to the cloud, their connectivity interfaces and the interaction layers are shown.
Figure 15 then describes the high-level framework for data and message transfers from a C- V2X Application Client, which may be resident in a vehicle, roadside infrastructure unit or personal communications device, to a cloud based V2X Application Server through an LTE mobile infrastructure58.
Figure 15: Architecture for delivering C-ITS messages over mobile networks
The above implementation of C-V2X primarily consists of the mobile network layer, V2X Application Server, the V2X Application Client and the Inter-change Server that ensures interoperability across different V2X Application Servers and backend systems.
The V2X Application Client has both a transmit and receive module and can be hosted inside the vehicle communications unit, on personal communication devices, or road-side units which are all provisioned with the required mobile connectivity, enabling the transmission of uplink unicast messages to the V2X Application Server.
The V2X Application Server is located at the backend or edge servers that are accessible by V2X Application Clients via mobile networks and uses downlink unicast, multicast or broadcast transmission to transfer data to the Application Clients58.
58 Essaili, A. E., Lomar, T., Nylander, T., & Zang, Y. (2019, October 25). Ericsson Blog. Retrieved from Ericsson Web site: https://www.ericsson.com/en/blog/2019/10/cellular-v2x-the-road-ahead-c-its-adas