GLOSSARY

Glossary

Plain definitions of the terms used across this site, written to be useful rather than exhaustive. Where a term has a boundary or a common misuse, that is noted.

A TO Z

Terms used across this site.

Glossary of terms
Term	Definition
ADAS	Advanced driver assistance systems. Vehicle features that sense the environment and warn or intervene, such as lane keeping, automatic emergency braking and adaptive cruise control.
Anomaly detection	A modelling approach trained only on normal examples, flagging anything sufficiently different. Used where failure or defect examples are too rare or too varied to enumerate.
ASIC	Application-specific integrated circuit. A chip designed for one purpose, offering the lowest unit cost and power at volume, at the cost of mask expense and no post-manufacture reconfigurability.
BLE	Bluetooth Low Energy. A short-range wireless protocol optimised for battery devices, giving zone-level to few-metre location with multi-year battery life.
CFR	Crest factor reduction. Signal processing that lowers a waveform's peak-to-average power ratio before amplification, so the power amplifier can be driven harder without hard clipping.
RAIN RFID	Passive UHF RFID built on the EPC Gen2 air interface and standardised as ISO/IEC 18000-63, promoted under the RAIN Alliance. The technology behind most retail, apparel and logistics item tagging; distinct from NFC, which is short-range HF.
DECT NR+	DECT-2020 New Radio. An ETSI standard recognised by the ITU as meeting IMT-2020 requirements, making it the first non-cellular technology admitted as 5G. It forms an autonomous decentralised mesh with no base station and no operator, in licence-exempt DECT spectrum, and is specified for very high device density — which suits item-level tracking where a per-device subscription would be uneconomic.
Design for test (DFT)	Circuitry added to a chip so that manufacturing defects can be detected: scan chains, test compression, memory BIST and boundary scan.
Digital front end (DFE)	The signal processing between baseband and power amplifier in a radio, typically comprising crest factor reduction and digital pre-distortion.
JESD204	A serial interface standard between data converters and logic, providing multi-lane links with deterministic latency and multi-device synchronisation — which is what allows channels across several converters to be sampled coherently.
Matter	An application-layer standard for smart home and building devices, carried over Thread, Wi-Fi or Ethernet, intended to give interoperability and a common commissioning experience across vendors.
Thread	A low-power IPv6 mesh networking protocol built on IEEE 802.15.4. Self-healing with no single point of failure, it reaches the wider IP network through a border router — a role a multi-protocol gateway typically fills.
eCPRI	Enhanced Common Public Radio Interface. The fronthaul transport carrying traffic between a radio unit and a distributed unit in an Open RAN deployment, running over Ethernet with strict timing requirements.
DPD	Digital pre-distortion. Applying the inverse of a power amplifier's non-linear characteristic to the signal before amplification, so the output is closer to what was intended.
Drift	The decay in a deployed model's accuracy as real-world conditions diverge from the training distribution, caused by input changes, class balance changes, criteria changes or sensor degradation.
Edge AI	Machine learning inference performed on or near the device producing the data, rather than in a cloud service.
EVM	Error vector magnitude. A measure of modulation accuracy, expressed as the difference between the transmitted symbol and its ideal position.
FPGA	Field-programmable gate array. Reconfigurable logic offering high performance without mask cost, and reprogrammable after deployment.
FPGA-to-ASIC conversion	Migrating a design validated on an FPGA into an ASIC for unit cost and power at volume, by removing FPGA-specific dependencies, adding test structures and proving functional equivalence.
IEEE 1588	The Precision Time Protocol standard, used to distribute accurate time across a network so distributed nodes share a common clock.
MES	Manufacturing execution system. The software layer tracking production orders, batch records and traceability between enterprise planning and shop-floor control.
MQTT	A lightweight publish and subscribe messaging protocol widely used for device telemetry. MQTT-SN is a variant with more compact encoding for constrained sensor networks.
NTN	Non-terrestrial network. Connectivity carried over satellite, used in tracking as a continuity layer where terrestrial cellular coverage is unavailable.
OCR and OCV	Optical character recognition reads printed characters; optical character verification confirms they match expected content and meet print quality requirements.
O-RAN	Open Radio Access Network. An architecture defining open interfaces between radio access network components, allowing elements from different suppliers to interoperate.
PAPR	Peak-to-average power ratio. How far a waveform's peaks exceed its average power, which determines how much amplifier headroom is required.
PLC	Programmable logic controller. The industrial controller that runs a production line, with which any added inspection or measurement system must integrate.
PVT	Process, voltage and temperature. The three variables across which a chip must meet specification, and the sensors that monitor them on-die.
Quantisation	Reducing the numeric precision of a model's weights and activations, typically to 8-bit integers, to cut memory footprint, bandwidth and energy at some accuracy cost.
Root of trust	The component a system's security ultimately depends on and which cannot be verified by anything beneath it. A silicon root of trust places that anchor in hardware.
RTL	Register transfer level. The abstraction at which digital designs are described in Verilog, SystemVerilog or VHDL before synthesis into gates.
SDR	Software-defined radio. A radio whose signal processing is implemented in reconfigurable logic or software, so waveform and coding can change after deployment.
SERDES	Serialiser and deserialiser. A block converting parallel data to serial for high-speed transmission and back again.
Static timing analysis (STA)	Verifying that a design meets its timing requirements across process, voltage and temperature corners, without simulation.
Sensor fusion	Combining measurements from multiple sensor types into a single estimate, which depends more on time synchronisation and calibration than on the fusion algorithm.
UWB	Ultra-wideband. A short-range radio technology giving sub-metre position accuracy, at the cost of an anchor network and higher energy per fix.
UVM	Universal Verification Methodology. A standard framework for building reusable, constrained-random verification environments for digital designs.

COMMON QUESTIONS

What engineers ask before they call.

Why does this glossary exist?

Because the same term means different things in different sectors, and because a definition written by the people doing the work is more useful than one assembled from marketing copy.

KEEP READING