1 What Ambient IoT is: a network that reads tags with no battery

1.1 Why anybody built this

Ambient IoT is a way for a mobile network to talk to tags that have no battery §4.1.

The founding study named the gap: uses existing technology cannot cover — high pressure, extreme heat or cold, damp; things that must be ultra-low in complexity, millimetres thick and maintenance-free; and places where a conventional battery is no use ^[1].

A tag is stuck to a thing: a pallet, a surgical instrument, a cow, a manhole cover. It runs on energy harvested from radio waves, light, movement or heat, holds an identity number and sometimes a small sensor reading, and answers only when it happens to have the power to answer. TS 22.369

1.2 The tag is the cheapest part of it

Around the tag stands the rest. A radio reads it. The AIOTF — the Ambient IoT Function, new in this work — runs the exchange: it triggers the radio, picks which base station and which readers do the work, and hands out the identifier that ties one request together §4.5.3.

Behind it sits the ADM, the store holding each device's profile, its credentials and the record of which outside application may ask for what §4.5.9. That application comes in through the NEF, the door the network keeps for outsiders §4.5.4.

The cheapest tag does not even transmit. A carrier-wave node nearby emits one plain tone, and the tag changes how much of that tone it bounces back — it reflects rather than sends TS 38.291. That is how it lives on about a microwatt of peak power TR 38.769.

1.3 The four jobs

Clause 4.3 of TS 22.369, the service requirements, reduces all of it to four. TS 22.369

1.4 Three of the real ones

The use cases behind those requirements are in TR 22.840. TR 22.840

A car plant. About 600,000 m², about 1,300 fixed readers, about 800,000 tags present at once, each reader reading 20 tags a second. Nobody is going to change 800,000 batteries.

Hospital instruments. Tags that survive steam sterilisation, carrying the instrument's serial number, usage status, usage records, years of use and maintenance status — 176 bits in all.

Medicine packets that light up. An 85-year-old is told which packet to take: the network lights a small light-emitting diode on the right one and switches it off when he confirms. That is actuator control.

Manhole covers are a fourth, with tilt, vibration and water-level sensors. The study opens that case with a man found dead in a manhole.

1.5 Where it sits, and the fence around it

The studies place it between two things people already know: more complex than an RFID tag, which only reflects a preconfigured identity when a reader's radio power excites it, and significantly less complex than a 3GPP CIoT device, the low-power cellular device 3GPP already had. TR 23.700-13

Then the architecture document's scope clause fences the whole of it in.

An SNPN is a stand-alone private 5G network, not an operator's public one. The fence was drawn in Release 19 and stands in the version loaded here; the security specification carries it in its title TS 33.369.

1.6 Which document to open for what

TS 23.369 is the architecture, and the document loaded behind this course: every clause number here opens beside it §3.1. TS 22.369 says what the system is for, TR 22.840 carries the use cases, TR 38.769 the physics of the tag. TS 23.369

Next, What an Ambient IoT system is made of names everything the system is made of.