BLE Glossary
Comprehensive glossary of BLE terms, protocols, standards, and technical concepts.
Fundamentals
Bluetooth Low Energy
Low-power wireless protocol in 2.4 GHz band for IoT devices.
Bluetooth Classic
Original Bluetooth BR/EDR for audio and file transfer.
Dual-Mode
Device supporting both Classic and LE Bluetooth.
ISM Band
2.4 GHz radio band shared by BLE, Wi-Fi, and Zigbee.
Frequency Hopping
Channel-switching technique to avoid interference.
Connection Interval
Time between BLE connection events (7.5 ms - 4 s).
Connection Event
Scheduled data exchange between BLE devices.
Central
Device that initiates and manages BLE connections.
Peripheral
Device that advertises and accepts BLE connections.
Slave Latency
Number of connection events a peripheral can skip.
PHY & Radio
LE 1M PHY
Mandatory 1 Mbps BLE radio layer.
LE 2M PHY
Optional 2 Mbps BLE PHY for higher throughput.
LE Coded PHY
Long-range BLE PHY using forward error correction.
TX Power
Transmit power level affecting range and consumption.
RX Sensitivity
Minimum detectable signal level for the receiver.
RSSI
Measurement of received BLE signal strength.
Link Budget
Sum of gains minus losses determining BLE range.
GFSK
BLE modulation scheme for efficient communication.
Channel Map
Bitmask of active BLE data channels.
Channel Sounding
Bluetooth 6.0 centimeter-accurate ranging.
GAP & Advertising
Advertising
BLE broadcast packets for device discovery.
Advertising Interval
Time between BLE advertising events.
Scan Response
Optional secondary BLE advertising data.
Extended Advertising
BLE 5.0 advertising with up to 255-byte payloads.
Periodic Advertising
Connectionless data broadcasting at fixed intervals.
PAwR
BLE 5.4 bidirectional periodic advertising.
Active Scanning
Scanning with SCAN_REQ for additional data.
Passive Scanning
Scanning by listening only, no requests sent.
Direction Finding
BLE 5.1 AoA/AoD for direction estimation.
Whitelist
Filter list of allowed BLE device addresses.
GATT & ATT
GATT
Framework for BLE data exchange via services/characteristics.
ATT
Low-level BLE protocol for reading/writing attributes.
GATT Service
Collection of related BLE characteristics.
GATT Characteristic
Data value within a BLE service with R/W/N properties.
GATT Descriptor
Metadata attached to a BLE characteristic.
CCCD
Descriptor enabling BLE notifications/indications.
Notification
Unacknowledged BLE server-to-client data push.
Indication
Acknowledged BLE server-to-client data push.
MTU
Maximum single-packet ATT payload size.
UUID
Identifier for BLE services and characteristics.
Security
Pairing
Establishing BLE security by exchanging keys.
Bonding
Persistent storage of BLE pairing keys.
LE Secure Connections
BLE 4.2+ ECDH-based secure pairing.
Legacy Pairing
Original BLE pairing (pre-4.2), now deprecated.
LTK
Stored encryption key for BLE reconnection.
OOB Pairing
BLE pairing via external channel (NFC, QR).
Just Works
No-interaction BLE pairing without MITM protection.
Passkey Entry
BLE pairing with 6-digit PIN entry.
Numeric Comparison
BLE pairing by confirming matching 6-digit numbers.
LE Privacy
BLE address rotation to prevent tracking.
Mesh
Bluetooth Mesh
Many-to-many BLE networking for IoT mesh.
Managed Flooding
Mesh message relay via rebroadcast with TTL.
Provisioning
Adding a device to a Bluetooth Mesh network.
Provisioner
Device that adds nodes to the Mesh network.
Relay Node
Mesh node that retransmits messages.
Friend Node
Mesh node caching messages for sleeping devices.
Low Power Node
Battery-powered Mesh node polling cached messages.
Directed Forwarding
Mesh 1.1 path-based message routing.
Publish-Subscribe
Mesh group addressing for pub/sub messaging.
Mesh Model
Standardized Mesh node behavior definition.
LE Audio
LE Audio
BLE-based audio with LC3 codec and Auracast.
LC3
LE Audio codec with better quality than SBC.
Isochronous Channels
Time-bounded BLE data delivery for audio.
CIS
Point-to-point BLE audio stream.
BIS
One-to-many BLE audio broadcast.
Auracast
LE Audio broadcast audio for public venues.
Audio Stream Control
Service managing LE Audio stream configuration.
BAP
Foundational LE Audio profile for audio streams.
CAP
LE Audio profile for coordinated audio sets.
EATT
BLE 5.2 parallel ATT bearers for throughput.
Protocols & Profiles
Bluetooth SIG
Industry body governing Bluetooth standards.
Core Specification
Main Bluetooth specification document.
L2CAP
BLE protocol for channel multiplexing and segmentation.
HCI
Interface between BLE software stack and radio hardware.
SMP
BLE protocol for pairing and key management.
DLE
BLE 4.2 larger packet payloads (251 bytes).
Connection Subrating
BLE 5.3 dynamic connection parameter adjustment.
Matter
Open smart home standard using BLE/Thread/Wi-Fi.
Thread
IPv6 mesh protocol paired with BLE in Matter.
Zigbee
802.15.4 mesh protocol for smart home.
Hardware & Implementation
SoC
Single chip with processor, memory, and BLE radio.
Module
Pre-certified BLE SoC with antenna on a PCB.
SDK
Vendor toolchain for BLE firmware development.
OTA Update
Wireless BLE firmware update.
PCB Antenna
2.4 GHz antenna traced on the PCB.
Chip Antenna
Miniature ceramic BLE antenna component.
Zephyr RTOS
Open-source RTOS with native BLE stack.
FreeRTOS
Popular open-source RTOS for BLE embedded systems.
Indoor Positioning System
BLE-based indoor location tracking system.
DCDC Converter
On-chip power regulator for better efficiency.
Frequently Asked Questions
Our glossary covers 90+ BLE technical terms organized by category. Each term includes a definition, related terms, and links to relevant chips and guides.