The Open Systems Interconnection (OSI) model is a reference model from the International Organization for Standardization (ISO) that "provides a common basis for the coordination of standards development for the purpose of systems interconnection." In the OSI reference model, the communications between systems are split into seven different abstraction layers: Physical, Data Link, Network, Transport, Session, Presentation, and Application.
A semi-trailer truck is the combination of a tractor unit and one or more semi-trailers to carry freight. A semi-trailer attaches to the tractor with a type of hitch called a fifth wheel.
KNX is an open standard for commercial and residential building automation. KNX devices can manage lighting, blinds and shutters, HVAC, security systems, energy management, audio video, domestic appliances, displays, remote control, etc. KNX evolved from three earlier standards; the European Home Systems Protocol (EHS), BatiBUS, and the European Installation Bus.
A controller area network (CAN) is a vehicle bus standard designed to enable efficient communication primarily between electronic control units (ECUs). Originally developed to reduce the complexity and cost of electrical wiring in automobiles through multiplexing, the CAN bus protocol has since been adopted in various other contexts. This broadcast-based, message-oriented protocol ensures data integrity and prioritization through a process called arbitration, allowing the highest priority device to continue transmitting if multiple devices attempt to send data simultaneously, while others back off. Its reliability is enhanced by differential signaling, which mitigates electrical noise. Common versions of the CAN protocol include CAN 2.0, CAN FD, and CAN XL which vary in their data rate capabilities and maximum data payload sizes.
A trailer is an unpowered vehicle towed by a powered vehicle. It is commonly used for the transport of goods and materials.
A vehicle bus is a specialized internal communications network that interconnects components inside a vehicle. In electronics, a bus is simply a device that connects multiple electrical or electronic devices together. Special requirements for vehicle control such as assurance of message delivery, of non-conflicting messages, of minimum time of delivery, of low cost, and of EMF noise resilience, as well as redundant routing and other characteristics mandate the use of less common networking protocols. Protocols include Controller Area Network (CAN), Local Interconnect Network (LIN) and others. Conventional computer networking technologies are rarely used, except in aircraft, where implementations of the ARINC 664 such as the Avionics Full-Duplex Switched Ethernet are used. Aircraft that use Avionics Full-Duplex Switched Ethernet (AFDX) include the Boeing 787, the Airbus A400M and the Airbus A380. Trains commonly use Ethernet Consist Network (ECN). All cars sold in the United States since 1996 are required to have an On-Board Diagnostics connector, for access to the car's electronic controllers.
Society of Automotive Engineers standard SAE J1939 is the vehicle bus recommended practice used for communication and diagnostics among vehicle components. Originating in the car and heavy-duty truck industry in the United States, it is now widely used in other parts of the world.
LIN is a network protocol used for communication between components in modern vehicles. It is a low-cost single-wire serial protocol that supports communications up to 19.2 Kbit/s with a maximum bus length of 40 metres (131.2 ft).
Dedicated short-range communications (DSRC) is a technology for direct wireless exchange of vehicle-to-everything (V2X) and other intelligent transportation systems (ITS) data between vehicles, other road users, and roadside infrastructure. DSRC, which can be used for both one- and two-way data exchanges, uses channels in the licensed 5.9 GHz band. DSRC is based on IEEE 802.11p.
Drive by wire or DbW technology in the automotive industry is the use of electronic or electro-mechanical systems in place of mechanical linkages that control driving functions. The concept is similar to fly-by-wire in the aviation industry. Drive-by-wire may refer to just the propulsion of the vehicle through electronic throttle control, or it may refer to electronic control over propulsion as well as steering and braking, which separately are known as steer by wire and brake by wire, along with electronic control over other vehicle driving functions.
A fieldbus is a member of a family of industrial digital communication networks used for real-time distributed control. Fieldbus profiles are standardized by the International Electrotechnical Commission (IEC) as IEC 61784/61158.
A tow hitch is a device attached to the chassis of a vehicle for towing, or a towbar to an aircraft nose gear. It can take the form of a tow ball to allow swiveling and articulation of a trailer, or a tow pin, or a tow hook with a trailer loop, often used for large or agricultural vehicles where slack in the pivot pin allows similar movements. Another category is the towing pintle used on military vehicles worldwide.
Brake-by-wire technology in the automotive industry is the ability to control brakes through electronic means, without a mechanical connection that transfers force to the physical braking system from a driver input apparatus such as a pedal or lever.
Keyword Protocol 2000, abbreviated KWP2000, is a communications protocol used for on-board vehicle diagnostics systems (OBD). This protocol covers the application layer in the OSI model of computer networking. The protocol is standardized by International Organization for Standardization as ISO 14230.
ISO 15765-2, or ISO-TP (Transport Layer), is an international standard for sending data packets over a CAN-Bus. The protocol allows for the transport of messages that exceed the eight byte maximum payload of CAN frames. ISO-TP segments longer messages into multiple frames, adding metadata (CAN-TP Header) that allows the interpretation of individual frames and reassembly into a complete message packet by the recipient. It can carry up to 232-1 (4294967295) bytes of payload per message packet starting from the 2016 version. Prior version were limited to a maximum payload size of 4095 bytes.
A number of ISO standards cover trailer connectors, the electrical connectors between vehicles and the trailers they tow that provide a means of control for the trailers. These are listed below, with notes on significant deviations from them that can cause problems.
Unified Diagnostic Services (UDS) is a diagnostic communication protocol used in electronic control units (ECUs) within automotive electronics, which is specified in the ISO 14229-1. It is derived from ISO 14230-3 (KWP2000) and the now obsolete ISO 15765-3. 'Unified' in this context means that it is an international and not a company-specific standard. By now this communication protocol is used in all new ECUs made by Tier 1 suppliers of Original Equipment Manufacturer (OEM), and is incorporated into other standards, such as AUTOSAR. The ECUs in modern vehicles control nearly all functions, including electronic fuel injection (EFI), engine control, the transmission, anti-lock braking system, door locks, braking, window operation, and more.
ISO 15118Road vehicles -- Vehicle to grid communication interface is a proposed international standard defining a vehicle to grid (V2G) communication interface for bi-directional charging/discharging of electric vehicles. The standard provides multiple use cases like secure communication, smart charging and the Plug & Charge feature used by some electric vehicle networks.
Automotive security refers to the branch of computer security focused on the cyber risks related to the automotive context. The increasingly high number of ECUs in vehicles and, alongside, the implementation of multiple different means of communication from and towards the vehicle in a remote and wireless manner led to the necessity of a branch of cybersecurity dedicated to the threats associated with vehicles. Not to be confused with automotive safety.
