Communications Definitions

As this industry moves very quickly, we get to make up new words, acronyms, standards, etc. Its all very exciting! But also, easy to get lost in, so here is a list of definitions for connected vehicles that you can read through to get your feet under you:

3GPP Third Generation Partnership Project, a partnership by major players in the telecom industry to create the 5th Generation of wireless communication

4G A set of performance standards for cellular communication known as the 4th Generation of wireless communication, services that meet these standards are offered by most cellular carriers in the United States

5G A set of performance standards for cellular communication known as the 5th Generation of wireless communication, this standard is currently under development and service expected to meet these standards is planned for 2020.  This service relies heavily on small cell communication

  • GHz The common name set aside for the bandwidth allocated to V2V communication by the FCC in 1999. This bandwidth sits just above the bandwidth used for cellular communications.

802.11p The standard for DSRC communications

ADAS  Advanced Driver Assistance Systems

Autonomous Vehicle (AV)  A vehicle that can operate, in some manner, without constant direction from the driver

Bandwidth The range between lowest allowed and highest allowed frequencies in a spectrum for a communication medium

BSM Basic Safety Messages, short communications sent via V2X to alert surrounding devices as to critical location, status or instructional information.  The contents of this transmittal have been defined and mandated as per SAE J2735

BSM II Basic Safety Message II, this is additional information that may be optionally added to a BSM and transmitted in the same manner.

C-V2X Cellular Vehicle to Everything, this is the common name for the communication of devices to other devices, either via traditional cellular tower interfaces (Uu) or optionally without the use of an intermediary tower (pc5) as defined in Release 14 and subsequent releases.

CAN bus Controller Area Network bus, this is the standard methodology for data transfer and internal communications within a vehicle’s computer system that serves to network all the interconnected components of that vehicle.

CAV Connected Autonomous Vehicle

Connected Vehicle (CV) A vehicle that can communicate with other vehicles and infrastructure

Dead Reckoning Calculating a position based on movements from a known coordinate

D2D Device to Device Communications, this is a generic terms for a communications system in which devices communicate directly with other devices

DSRC Dedicated Short Range Communications, a wireless communication channel with corresponding standards and protocols designated for V2X communication.

FCC Federal Communications Commission, the federal unit that allocates spectrum for wireless use

FCW Forward Collision Warning, a vehicle alert to indicate an imminent forward collision

Frequency A particular electromagnetic wave designation, based on a measurement of how often the peaks of the wave are registered to the receiver

GNSS Global Navigation Satellite Systems, this is the generic term for satellite based localization systems. GPS is a GNSS

HSM Hardware Security Module, this is the piece of equipment that offers cybersecurity

IMU Inertial Measurement Unit, this tracks the acceleration, deceleration and movement of a vehicle based on readings of inertia.

IOT Internet of Things, a next generation concept pertaining to widespread use of devices that are networked together or can otherwise communicate

Levels of Autonomy A categorization system for vehicles with a variety of combinations of autonomous subsystems.  Rated 0 (no autonomy) to 6 (full autonomy). Level 3 vehicles are expected to take control of driving to the car for periods of time (like stretches of highway), Level 4 vehicles are expected to take control for a significant portion of the time, and Level 5 vehicles are expected to need no human interaction for steering purposes.

LTE Long Term Evolution, the 4th generation mobile communication standard

MEC Multi Access (or Mobile) Edge Computing, this is the organizational concept where operations are handled not in a centralized cloud, but in dispersed nodes around the system

Multipath Propagation The description for radio signals that may utilize multiple paths to arrive at a point.  For instance, one signal may be directly received but another may reflect off of something and be received slightly later.

NHTSA National Highway Transportation Safety Administration, they are the federal regulating body for autonomous vehicles

NPRM Notice of Proposed Rule Making, the process by which a federal agency creates a new administrative rule.

OBU Onboard Unit, these are devices that are contained within a vehicle

PC5 an LTE device interface methodology in which an intermediary system is not utilized, and devices communicate directly with other devices.

Queue Warning A vehicle warning that traffic is slowed or stopped up ahead

Release 14 The 3GPP Release 14 specification, which notably includes standards for D2D communications along the 5.9 GHz channel.  This release offers devices (and vehicles) the opportunity to transmit messages to each other directly, without the use of intermediary towers.  This release places cellular directly in competition with DSRC for V2X communications.

Ridesourcing what was previously referred to as Ridesharing, this is the acquirement of rides from a third party service provider, usually a TNC

RSU Road Side Unit, these are devices that are attached to roadway infrastructure

SAE Society of Automotive Engineers, a standards organization involved in creating automotive standards

SAE J2735 the SAE standard pertaining to the transmission of BSMs

SAE J2945 the onboard standard pertaining to V2V performance

SLAM Simultaneous Localization and Mapping, this is a machine vision concept in which a vehicle draws a 3d map of the world around it and, concurrently, locates itself in relation to that map.

Small Cell cellular radio access nodes that require low power and operate in ranges from 10 meters to a few kilometers.

SPaT Signal Phase and Timing, critical information regarding signal light timings.

Spectrum The designated range of electromagnetic spectrum in which wireless communications travel

TIM Traveler Information Message

TNC Transportation Network Company, a company that offers rides for a fee, generally associated with entities such as Uber and Lyft.

V2I  Vehicle to Infrastructure Communications, the methodology cars use to “talk” to infrastructure

V2V  Vehicle to Vehicle Communications, the methodology cars use to “talk” to other cars

V2X  Vehicle to Anything Communications, the methodology cars use to “talk” to infrastructure, or other cars or any IOT enabled device

VANET Vehicle Ad-hoc network, the network established around a grouping of communicating vehicles.

VIO Visual inertial odometry, similar to SLAM, but with the addition of inertial data

Ultra-wideband  a very low energy level for short-range, high-bandwidth communications over a large portion of the radio spectrum – can be used to help with positioning

Uu an LTE device interface methodology in which an intermediary system (a cell tower) receives, coordinates and transmits communication to network devices.