Integrated Sensing and Communication (ISAC)

Integrated Sensing and Communication lets a single cellular network do two jobs at once: carry normal traffic and sense its surroundings by radio. Instead of bolting on separate radar hardware, ISAC reuses the same spectrum, waveforms, and base stations to detect and track objects, monitor environments, and read human motion — turning the network itself into a distributed sensor.

In 3GPP, ISAC is defined across two layers. The service requirements (Stage 1, TS 22.137) set out what the system must do; the architecture (Stage 2, TS 23.137) adds a new core network function, the Sensing Function (SenF), which authorises requests, selects the base stations that will sense, gathers their measurements, and returns results to the requesting application through the exposure function. The base station (gNB) acts as the sensing entity, and in the current release the focus is network-based sensing — with aerial objects such as drones as the first target.

The specifications frame seven service categories, from outdoor and indoor object tracking to environmental monitoring, public-safety sensing, vehicle tracking, motion monitoring, and fine-grained gesture recognition. Each carries its own targets for positioning accuracy, resolution, latency, refresh rate, and detection reliability, with security, privacy, consent, and energy efficiency treated as first-class concerns.

Looking toward 6G (Releases 20–21), ISAC becomes a defining capability, converging with sub-THz spectrum for finer resolution, AI-native processing, digital-twin networks, and extreme positioning. The full analysis below covers the roadmap, architecture, procedures, KPIs, and open issues in detail.

ISAC_6G.pdf — complete technical analysis built from 3GPP TS 22.137, TS 23.137 and the Release 20 overview.