Connected-car technology has become a key differentiator for carmakers and and their Tier 1 suppliers. One of the biggest challenges connected cars pose is the integration of information and consumer electronics into the car and ensuring connectivity among them. Connected car applications such as telematics, driver assistance, and infotainment require seamless connectivity to and from the vehicle.
Modern cars are built with embedded computers called ECUs (electronic control units) that are further connected to sensors for data acquisition. The in-vehicle network is further divided into sub-networks such as CAN (controller area network), MOST (media-oriented safety transport), and FlexRay. The choice of the bus network depends on the communication requirements of the connected ECUs and the baseline vehicle platform out of which a new vehicle line is derived.
Moreover the vehicles of today are able to exchange data with external sources via Bluetooth, Wi-Fi, 3G (third-generation), and LTE (long-term evolution) networks. The advent of V2V (vehicle-to-vehicle) and V2I (vehicle-to-infrastructure) communication has increased this trend.
In addition to communication inside the vehicle, a robust vehicle communication gateway is important to establish seamless connectivity to conditions outside the vehicle. While the communication network inside the vehicle is stable, V2I and V2V communication to the outside is undergoing rapid change.
Vehicle gateway challenges
With advancements in telematics, connectivity challenges in vehicles have also changed drastically. The vehicle gateway of the future should be designed to address the following challenges:
1. Support multiple networks and provide secure wireless connectivity for/between vehicles and infrastructure
2. Provide secure, intelligent switching between different networks
3. Sense, select, and switch to best available network automatically based on user-defined policies
4. Create a mobile hotspot for wired and wireless devices in and around the vehicle
5. Support various IP devices in the vehicle
6. Support upgradeability for current and future networks
7. Provide secure and reliable communication for all connected devices.
Vehicle internal networks are now more connected to external devices, thereby exposing the internal network to the outside world. The evolution of V2V and V2I communication has increased data exchange with external resources via Wi-Fi, 3G, and LTE networks.
Vehicles are no longer closed networks; they are potential targets for remote attacks. In-vehicle networks are safety-critical, and any access to an in-vehicle network may have serious safety implications. Therefore, both internal and external communication networks must be secured.
With the increased complexity of telematics services and applications, the big challenge is not about providing a platform with extensive features, but creating a future-ready vehicle gateway that has the flexibility to adapt and accommodate rapid changes and the ability to support new functionality that holds the key.
Integrated automotive gateway blueprint
The automotive gateway should provide a secure communication for data exchange, both onboard as well as off-board. The gateway proposed by Tech Mahindra is directly involved in supporting various mobility and safety applications that run either inside the vehicle or those hosted on a mobile or off-board platform using remote servers. The company is focusing its development on the concept of an Automotive Gateway Architecture blueprint and its realization.
The gateway supports various short-range communication systems for connecting to personal devices such as mobile phones, tablets via Bluetooth, Wi-Fi, and UART (universal asynchronous receiver/transmitter). To connect to the cloud via the Internet, the gateway supports long-range communication systems such as GPRS (general packet radio service), CDMA (code division multiple access), LTE, UMTS (Universal Mobile Telecommunications System), and GSM (Global System for Mobile). IEEE 802.11p is supported for V2V communication and communicating with road-side units. The gateway architecture has to be designed for supporting connectivity with known and unknown entities.
Known entities could be trusted entities such as firmware over-the-air (FOTA) servers, telematics services over backend servers, or service/plant diagnostics over Wi-Fi, while unknown entities refer to untrusted ones such as third-party applications, open cloud connections from in-vehicle devices, and smart devices brought into the vehicle connectivity network.
The software architecture is designed with a plug-and-play approach to ensure support to new connectivity changes without altering the core software.
The system architecture under consideration directly relates to connectivity mechanisms. The physical layer is 802.11p instead of 802.11 b/g/n. The vehicle gateway carries two stacks, namely:
1. IPv6 (Internet Protocol version 6) based TCP/UDP (Transmission Control Protocol/User Datagram Protocol) for supporting non-safety applications like e-toll, traveler info, construction management, commercial vehicle operations, etc.
2. WSMP (Wave Short Message Protocol) stack for safety applications such as curve speed warning, V2V-sensor data exchange, left-turn assistant, etc.
IPV6-based TCP/UDP will enable a secure and seamless connection from gateways to portal/Internet. WSMP allows applications to directly access/control physical layer characteristics without access points for ad-hoc communications.
The gateway must support multiple PHY (physical layer) requirements (connect to smart services inside the vehicle and 3G networks for telematics) to enable a range of infotainment and telematics applications.
To ensure V2X, telematics, and infotainment functions, the gateway solution must support and implement the IEEE 802.21 specification for “handover between heterogeneous networks” to ensure seamless handover between network switches and controls when the vehicle is on move.
A true future-ready automotive gateway should be able to send IPv6 packets over 802.11p and 3G networks with a seamless vertical handover. Seamless handover happens when the vehicle is moving through and different WLAN (wireless local area network) and 3G networks, constantly switching between heterogeneous networks for always best connected services.
Security model of the gateway
Initially, in-vehicle networks were designed to operate in a closed environment where security was not a major concern. Considering that the gateway must support V2X communication and a number of external interfaces to in-vehicle networks, threat levels are perceptibly higher with consequent increases in safety and security requirements.
The security mechanism in the gateway must be designed to contain attacks by rooting the security mechanism on hardware with crypto algorithms. This ensures that sensitive information such as cryptographic keys is not vulnerable to software attacks. The hardware security module protects the key store, acting as crypto hardware and supporting well-defined software interfaces. Hardware-based security is proposed to handle ad-hoc message exchange load in varying high-speed road traffic conditions.
The security module must be designed for use in combination with vehicle manufacturers’ security policies. Additionally, the gateway security mechanisms must be clearly intended for generic connectivity to vehicular networks as operational environments change dynamically.
Enabling future convergence
Data encryption and the security of the telematics backend have been primary concerns in automotive telematics. The automotive gateway will act as a convergence point for the cooperative networks of the future, which will support a variety of safety critical and mobility applications that either run inside the vehicle networks or are hosted on smart devices or on remote servers. In next-generation telematics, in which vehicles will connect ad-hoc to random entities and route data through unknown networks along the way, all-round vehicle security will be of paramount significance.
The automotive gateway is expected to play a significant role in vehicle security in addition to its traditional data gateway functionality. While the future of connectivity infrastructure is speculative, we know the broad outlines of what might transpire. The automotive gateway has been envisioned based on these broad outlines. The adoption of the gateway approach will, ultimately, ride on the ease of providing seamless connectivity over the vehicle’s mobility envelope, safely and securely.
This article was written for Automotive Engineering by Karthik P. Rao, Consultant, and Balakrishnan Muthukrishnan, Principal Consultant, for the Connected Cars Practice at Integrated Engineering Solutions, Tech Mahindra.