Driven by the National Highway Transportation Safety Commission’s (NHTSA) fast-track regulations, the next few years will see the rollout of a whole new generation of connected “smart cars.” These new vehicles will be in constant wireless communication with both each other and a network of traffic management centers, providing a stream of information about real-time traffic conditions. When fully implemented, benefits will include fewer deaths on the roads, less traffic congestion, and large savings in time, money, and gasoline.
You’re probably already familiar with wireless communication from a vehicle to a fixed ground station. GM's OnStar has been around since 1995, employing CDMA mobile phone technology for both voice and data communication. More recently, Ford, Chrysler and BMW have introduced systems that give access to a variety of safety, convenience and infotainment services. But the next generation of smart cars will go far beyond these proprietary systems.
Vehicle-to-infrastructure (V2I) systems will allow vehicles to communicate wirelessly with traffic lights, road signs and other infrastructure. Vehicle-to-vehicle (V2V) communications will allow vehicles to talk directly to one another, exchanging information about speed, direction and location. Collectively, the two systems are known as V2X.
Figure 1: Vehicle safety scenarios with V2X. (Source: IEEE.org)
An NHTSA report estimates a V2V system would address up to 79 percent of potential vehicle crashes, and V2I systems would address 81 percent of all crashes.
How could drivers benefit from intelligent, connected vehicles?
• Lane-passing assistance: Intelligent cars would be able to assist the driver in lane-passing situations where they did not have a clear view. With V2V communication, vehicles could warn each driver of oncoming cars to avoid head-on collisions.
• Intersection assistance: Intelligent vehicles would be aware of other approaching vehicles entering an intersection and could alert the driver or apply the brakes.
• Reduction in congestion: The V2I system would alert drivers of traffic congestion, reducing crashes and minimizing traffic delays; a proposed network of traffic management centers (TMC) would communicate with each vehicle via Wi-Fi, dedicated short-range communication (DSRC) systems, satellite, or cellular systems. Intelligent traffic lights could change state based on traffic patterns over a wide area to minimize overall congestion.
• Time and money savings: V2I would be able to help reduce the amount of gas wasted in traffic jams each year, saving drivers time (about 5.5 billion hours a year) as well as fuel—approximately 1.9 billion gallons a year.
• Expanded safety applications: Intelligent vehicles would be able warn drivers of such situations as a stationary or parked vehicle; if a vehicle ahead stopped or slowed suddenly; or if traffic patterns changed abruptly.
These systems are expected to start rolling out sooner than you might think. GM CEO Mary Barra announced at the Intelligent Transport System World Congress in Detroit in September 2014 that V2V technology would be included in the 2017 Cadillac CTS. The system will be provided by Delphi using application software from Cohda Wireless and NXP’s wireless chipset. And just this May, U.S. Transportation Secretary Anthony Foxx announced an accelerated schedule for NHTSA’s proposal to require V2V equipment on new vehicles.
Privacy and Security Concerns
Of course having a connected vehicle has many benefits, but it comes with drawbacks, too. Privacy and security are both issues that have yet to be addressed effectively; the problems will only grow more urgent as wireless connectivity spreads.
Privacy when driving is already compromised, even on existing vehicles. A 2015 report from U.S. Senate staffers found that 50 percent of automakers offer technologies that collect and wirelessly transmit driving history data to data centers, including third-party data centers. The precise data gathered varies by manufacturer, but can include current location, vehicle speed, last location parked, as well as distances and times traveled.
Figure 2: Percentage of automobile manufacturers that collect and transmit driving history data. (Source: Office of Senator Edward Markey)
With regard to security, most existing vehicle networks were not designed to be secure. According to experts at a recent cybersecurity conference, most vehicles have over 50 vulnerable “attack points.”
We’re not talking solely about wireless connections. Modern vehicles have up to 50 embedded controllers that talk to each other over local networks such as Controller Area Networks (CAN) and Local Interconnect Networks (LIN). With 100 million lines, the total amount of code that must be secured dwarfs that in other complex applications, as shown in Figure 3.
Figure 3: Software size comparison by lines of code. (Source: Delphi)
The consequences of a security failure can be financial—the theft of a vehicle—or even fatal. In a 2013 study funded by the Defense Advanced Research Projects Agency (DARPA), two researchers demonstrated their ability to connect a laptop to two different vehicles’ computer systems using a cable, send commands to different control units through CAN, and thereby control the engine, brakes, steering, and other critical vehicle components. More recently, hackers have remotely accessed a vehicle while on the highway and succeeded in disabling engine operation.
When such problems are discovered, they can typically be fixed by a security patch—as was the case in the examples given—but much more is needed. Many of the same issues are being faced by the IoT community, so there’s a lot of effort being devoted to developing robust, standardized encryption and authentication solutions.
Apart from the direct threat to the vehicle, other security-related areas that automotive suppliers (and their lawyers) are concerned about include:
• Security of mobile media information such as copyrighted video and audio being used in the car,
• Security of in-vehicle parameters such as engine calibrations, odometer reading, etc.,
• Accuracy and validity of in-vehicle parameters such as vehicle speed,
• Integrity of emissions-control systems, and
• Detection of counterfeit ECUs.
V2I and V2V Technology Overview
V2V and V2I have been a long time coming. In 1999, the Federal Communications Commission (FCC) allocated 75 MHz of spectrum in the 5.9 GHz band (5.850-5.925 GHz) for intelligent transportation systems (ITS). In Europe, ETSI followed suit with a 30MHz allocation in 2008.
From a technical perspective, DSRC systems for V2V/V2I use differ from conventional mobile communication systems in several ways:
1) Users (vehicles) may communicate with each other without relying on a dedicated coordination element (base station or access point);
2) Both source and destination stations are mobile and they can move at high vehicular speeds (> 120 km/h);
3) Communications between users take place at ground level, so that the effects of three-dimensional scattering become significant; and
4) The system’s range is small, typically about 400 meters.
These differences call for the design of novel transceivers for V2V DRSC systems that achieve a high spectral efficiency under harsh propagation conditions.
The IEEE 802.11p amendment to IEEE 802.11 (the Wi-Fi standard) defines enhancements to support ITS, using 10 MHz instead of 802.11’s 20 MHz channels. Half the bandwidth equates to double the transmission time for a specific data symbol. This allows the receiver to better cope with the characteristics of the radio channel in vehicular communications environments—signal echoes reflected from other cars or houses, for example.
Due to the potentially very brief time available for communications, the authentication and data-confidentiality mechanisms provided by the IEEE 802.11 cannot be used, so they must be provided by higher network layers. The IEEE 1609 family of standards for Wireless Access in Vehicular Environments (WAVE) defines an architecture and a complementary set of protocols, services and interfaces that collectively enable secure V2V and V2I communications.
Figure 4: NXP/Cohda MK5 802.11p Radio Module (Source: NXP/Cohda Wireless)
Semiconductor supplier NXP demonstrated its secure connected car technology at the Consumer Electronics Show (CES) in January. The NXP RoadLINK™ chipset, the basis for the V2X communications demo, is small enough to be mounted in a rooftop shark’s fin antenna and uses a multi-standard ITS architecture, including IEEE 1609.2 security for key storage and message signing.
The MK5 radio module in Figure 4, co-developed by NXP Semiconductors (hardware) and Cohda Wireless (firmware), includes the SAF5100EL transceiver, two 5.9 GHz antennas, and USB, SPI and GPIO interfaces. It measures 30 mm x 40 mm x 4 mm including the RF shield. The transceiver includes a software-defined radio with an IEEE 802.11p PHY and MAC.
The Next Stage: Autonomous Vehicles and V2X
Another potentially revolutionary development in smart vehicular transportation is the autonomous vehicle, which is capable of sensing its environment and navigating without human intervention. The NHTSA has proposed a formal classification system for autonomous vehicles ranging from Level 0—whereby the driver completely controls the vehicle at all times—to Level 4—where the vehicle performs all safety-critical functions for the entire trip and the driver is not expected to control the vehicle at any time. Note that “autonomous” as defined by auto makers is not the same as “self-driving;” the second term implies complete independence (i.e., no steering wheel or other controls).
The next stage in intelligent vehicles is also on the horizon. Google is already conducting testing of its autonomous car in San Francisco, which has already racked up 300,000 driving miles, including 50,000 miles without any intervention from drivers. The only documented accident was a fender-bender that occurred with a human at the controls.
By 2016 Mercedes plans to introduce its “Autobahn Pilot,” which will allow hands-free highway driving with autonomous passing of other vehicles. That same year, technology company Mobileye expects to release hands-free driving technology for highways. Even apart from the technology, numerous issues still need to be resolved, including liability for damage, licensing, and individual resistance.
It is expected that autonomous vehicles will fully integrate V2I and V2V technologies as they become available. When that day comes, perhaps we’ll finally be able to relax with a glass of wine or take a nap on our way home after a trying day at the office.