Products & Applications Multi-standard radio chips’ role in connected cars
Radio technology plays a decisive role in the networking of vehicles. Chips that can handle several radio standards facilitate the development of multifunctional solutions. An overview
With the increasing functional density in today's modern vehicles, significant advances are being made in terms of fuel consumption, comfort and the safety of all road users. Conventional mechanical systems are being replaced by fully electronic alternatives. This reduces production costs and the overall weight of vehicles and also helps to reduce fuel consumption. The widespread introduction of ADAS (Advanced Driver Assistance System) will make it possible to eliminate human error while driving, resulting in fewer accidents. Wider networking of our cars is critical to the advancing development of the automotive sector - to a point where autonomous driving becomes commonplace.
State-of-the-art radio technology, supported by a high bandwidth Ethernet-based fixed network infrastructure, enables vehicle-to-vehicle (V2V) and vehicle-to-infrastructure (V2I) communication. With the introduction of Intelligent Transportation Systems (ITS), vehicles will be able to transmit data regarding their current speed, position, direction of travel, etc. The system will also be able to communicate with other vehicles in the future. With V2I/V2V, valuable information can be exchanged between vehicles as well as with roadside fixed infrastructure to warn of traffic jams or other problems that could interfere with the smooth flow of traffic.
Vehicles can receive information from other cars in the immediate vicinity, alerting them to potential hazards ahead. The first instance of such a system is the Basic Service Messages (BSM), which has been defined as part of the Dedicated Short Range Communication (DSRC) standard in North America. This also makes it possible to interact with traffic lights so that the ADAS can decide whether it is worth braking in time to be able to continue driving when switching to green. This saves fuel by eliminating the need to brake at the last second and then accelerate.
802.11ac enables data rates of several 100 MBit/s
Among the radio communication protocols currently used in vehicle construction is Wi-Fi in various variants. 802.11ac is mostly used. It operates in the 5 GHz frequency band and ideally enables data rates of several 100 Mbps. This bandwidth is available for communication between smartphones and other portable electronic devices and the vehicle's navigation and infotainment systems. It can also be used to set up a WLAN hotspot that allows car passengers to share a mobile connection. Firmware over the air (FOTA) updates are also possible. This enables manufacturers to update a vehicle with new or improved functions without having to order it to a garage.
If an application requires only a short-range, the 802.11p standard is also suitable. 802.11p operates in the frequency band from 5.85 to 5.925 GHz. It is very well suited for use in the automotive industry as it is designed for reliable, low-latency data connection for V2V and V2I communication. The protocol uses a total of seven communication channels, each with a bandwidth of 10 MHz). Six of them are service channels, the remaining channel is used for control tasks. 802.11p has been tested for almost a decade and is now ready for use in V2V/V2I communication. The decision of the US National Highway Traffic Safety Administration in December 2016 highlights this technology in particular.
In addition to Wi-Fi, Bluetooth 5 also plays an important role in the introduction of networked vehicles. The radio technology offers a range 4 times greater than the previous Bluetooth 4.0 and also supports significantly higher data rates. Drivers and passengers can not only connect their portable devices to access music content. Hands-free control is also possible, and there are many other options. The improved features of Bluetooth 5 allow vehicles equipped with it to interact with V2I beacons at the roadside. This allows traffic jams to be avoided, tolls to be paid and emergency services to be supported to be able to react more quickly in the event of accidents.
First ICs combine Bluetooth 5, 802.11ac (Wave 2) and 802.11p
Leading automotive manufacturers, their Tier 1 supplier and the semiconductor manufacturers they work with have realized that the success of networked vehicles depends heavily on, among other things, the development of highly integrated wireless solutions. Despite their small size, these solutions must be able to process several protocols that are designed to be robust for automotive environments. One such radio combo SoC is the AEC-Q100-certified 88W8987xA series from Marvell. These are the first ICs to combine Bluetooth 5, 802.11ac (Wave 2) and 802.11p, offering developers everything they need for the new generation of networked vehicles.
The series includes three size-compatible SoCs offering 802.11ac with Bluetooth 5; 802.11p with Bluetooth 5; and selectable 802.11ac/802.11p with Bluetooth 5. Depending on the vehicle model, different versions can be installed so that basic and mid-range models can be equipped with the basic functions and luxury models with comprehensive functionality. The SoCs are pin-compatible. They can be replaced without the need for any modifications to the circuit board. The equipment features of the respective vehicle model can thus be easily adapted. This results in a versatile and cost-effective platform approach that will meet future requirements.
The 802.11p/Bluetooth version and the selectable version of the 88W8987xA series are suitable for telematics control units (TCU) and ADAS-based applications where the focus on data connectivity is mainly outside the vehicle. The 802.11ac/Bluetooth version is mainly used for in-vehicle infotainment (IVI). Vehicle manufacturers, however, have sufficient flexibility to adapt these functions to their architecture and application. In the TCU, for example, the Bluetooth function could enable Remote Keyless Entry (RKE) or Passive Entry Passive Start (PEPS). The safety/data protection functions integrated into Bluetooth 5 are an important aspect here.
Onward to comprehensive networking of vehicles
By integrating a Wi-Fi/Bluetooth combo IC into the head unit of a vehicle, valuable IVI functions are available through interaction with the driver's smartphone. Without the driver having to reach for his smartphone, login information can be exchanged via BLE to establish a Wi-Fi-based, high-bandwidth connection within the vehicle. All relevant applications are then projected onto the head unit while the vehicle is in motion so that the driver is not distracted and can keep an eye on the road ahead.
The desired applications/services are accessed via the in-vehicle interface (including voice commands). If the interface switches to Wi-Fi, the driver's music collection can be played back in HD audio. The voice quality of telephone calls is very good. This is made possible by the radio-based Apple CarPlay or Android Auto Projection app. In this mode, a hotspot can also be made available to other vehicle occupants, who can then share an LTE mobile phone connection within the vehicle.
At the same time, this hotspot enables streaming by radio, for example, to supply entertainment screens in the rear of the vehicle. If required, other portable devices can be connected via Bluetooth. It would even be possible to install radio-based cameras in the vehicle to stream videos to the head unit, which can be displayed to the driver as a context-related assistance function.
Radio technology, as described in this article, brings us closer to the goal of fully networking cars on our roads. The longer range of Bluetooth 5, the higher data rates of 802.11ac and the more robust and responsive 802.11p feature can help vehicle manufacturers to have radio technology that will make autonomous driving a reality one day. Using compact radio modules and common software drivers for different operating systems (such as Linux, Android, and QNX), not only can development times be significantly reduced, vehicle manufacturers and Tier 1 suppliers now have a radio link that covers different configurations.
This article was previously published in German on next-mobility.news.
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