Bluetooth

Bluetooth 5 (encompassing v5.0 through v5.3) significantly expanded Bluetooth Low Energy with 2 Mbps high-speed (2M PHY), up to 4x range extension via forward error-corrected Long Range (Coded PHY), 8x advertising broadcast capacity (Advertising Extensions), and Isochronous Channels (v5.2).

Bluetooth Channel Sounding (standardized in Bluetooth Core Specification v6.0) introduces high-precision, secure distance measurement to Bluetooth Low Energy. Utilizing Phase-Based Ranging (PBR) across multiple RF channels combined with Round-Trip Time (RTT) time-of-flight measurements, it delivers centimeter-level spatial accuracy and relay-attack security for digital car keys and item tracking.

Bluetooth Classic encompasses Bluetooth Core Specifications v1.0 through v3.0 + HS. Operating in the 2.4 GHz ISM band across 79 channels with Frequency-Hopping Spread Spectrum (FHSS), it established wireless audio (A2DP), hands-free telephony (HFP), and serial peripheral connectivity (SPP/HID) at data rates up to 3 Mbps.

Bluetooth 5.4 and LE Audio represent a complete architectural overhaul of Bluetooth audio and retail IoT. Powered by the Low Complexity Communication Codec (LC3), Isochronous Channels, Auracast broadcast audio, and Periodic Advertising with Responses (PAwR), it delivers superior audio quality at half the bitrate and supports multi-thousand device Electronic Shelf Label (ESL) networks.

Bluetooth Low Energy (BLE / Bluetooth Smart) was introduced in Bluetooth Core Specification v4.0 (2010) and enhanced through v4.2 (2014). Operating across 40 channels in the 2.4 GHz band, it replaced continuous connection streams with an event-driven Generic Attribute Profile (GATT) architecture, enabling devices to operate for years on a single coin cell battery.