Connected Cars and safety

04 Apr 2016 Vehicle Technology
To increase safety on our roads, intelligent networking and digitalization inside and outside the vehicle is set to play an increasingly important role in the future. “Connectivity” means that vehicles can communicate both with each other (vehicle- to-vehicle, or V2V) and the road infrastructure (vehicle-to-infrastructure, or V2I) such as stoplights and traffic management systems. This communication – also known under the umbrella term “car-to-X” communication – warns and informs drivers instantly of hazardous situations along the route, even if these are not yet visible to the driver themselves. During highly or fully automated driving, the vehicle would brake autonomously in such cases or change lanes in order to bypass the hazard at a safe distance without the driver having to intervene.
Various communication technologies are available for ensuring the required level of connectivity, including:
  • Standardized, general-purpose short-distance technology (BluetoothTM, Wi-Fi, wireless power, NFC etc.)
  • Technology developed specially for vehicle connectivity (e.g. IEEE 802.11p, a Wi-Fi-like short-distance communication standard for V2V and V2I)
  • Mobile network coverage (GSM, UMTS, LTE and all associated variants)

A comparison of technologies

The enforcement of a ban on using cellphones in the car without a hands-free kit has contributed to the popularity of Bluetooth technology, which allows drivers to control incoming and outgoing calls via the dashboard and connect the audio signal to the hands-free microphone and loudspeaker in the vehicle. Standardization was advantageous here because the Bluetooth Special Interest Group has developed a specific profile for this scenario: The hands-free profile (HFP).
Wi-Fi is the certified and generally preferred process for providing vehicle occupants with infotainment services. The car itself can act as a hotspot. Wireless power allows wireless charging of cellphones, smartphones and other devices without any action on the part of the user – that is, without the driver having to perform any distracting task; at the same time, the mobile device is always ready to communicate (in the car via Bluetooth and fully charged when the driver leaves the vehicle). IEEE 802.11p – a technology similar to Wi-Fi – was developed to facilitate V2V and V2I communication. There is, however, still a long way to go before this technology becomes widespread in the automotive industry because it can be leveraged to its full potential only when used on a mass scale and the necessary investments are made in the (road) infrastructure.
In the field of connectivity, mobile communication technologies are not only an important basis for V2V and V2I communication but also the key to on-board eCall emergency call systems, which, by March 31, 2018, will be mandatory EU-wide in all cars and light-duty commercial vehicles presented for homologation at that time. In the event of a serious accident, the system ensures that emergency medical services are alerted, even if the driver or other vehicle occupants are themselves unable to make an emergency call or speak on the cellphone. According to the European Parliament, eCall could potentially reduce the number of traffic fatalities by 10% per year. The member states are required to install the necessary infrastructure by October 1, 2017.

Ensuring connectivity is a key safety requirement

eCall is standardized for use in 2G (GSM) or 3G (UMTS) networks, but not in 4G (LTE) networks – network operators, however, are already implementing 4G and are currently testing future 5G networks. Although 2G networks have universal coverage in Europe, they are set to be disabled in the not-too-distant future. 3G networks already have good coverage in Europe. Something else that has to be considered, however, is the frequency band. In Europe, there are multiple frequency bands used for 2G and 3G, which means that an eCall modem has to support different frequency bands to ensure interaction with mobile communication networks in the whole of Europe. LTE/4G is a mobile communication network featuring state-of-the-art technology only recently introduced by network operators. However, LTE is a non-voice technology used exclusively for transmitting data.
Most smartphone users want high-speed data transmission, but are unaware that this technology does not support voice calls. Voice calls are possible only because the telephone itself switches down to 3G mode when a call is received or the user makes a call, although this is set to change when the new VoLTE technology is launched, which is currently undergoing testing and which some operators have already introduced. Test programs for these devices should therefore definitely ensure that eCall is supported not only by 2G or 3G cellphones and modules but also by 4G cellphones and modules.
In summary, the functions featured in most “connected car” applications rely on communication technology. For non-safety-related applications, the loss of signal is not critical – users can easily check whether or not connectivity is available. For safety-related services and applications like eCall, however, warnings should be issued to inform users of any loss of communication capability. The system should also be able to automatically restore functionality as soon as the signal is stable again.