DECT

showstack / protocols / dect

Also called DECT wireless intercom, 1.9 GHz.

The radio behind most modern wireless intercom beltpacks. It sits in a band reserved for it in many jurisdictions, which is the main reason it displaced 2.4 GHz systems on show sites: it is not competing with the venue's Wi-Fi. Full duplex, digital, and it roams between antennas as a user walks.

Audio transportPaid specETSIReported

Media Large, continuous, on time and in order

Continuous streams that are large enough to be sized properly, and that must arrive in order and on time.

What kills it. Anything that starves the link — usually a management transfer nobody scheduled — and jitter that outruns the receive buffer.

The four flows, and why the model is worth having →

What it carries

Sample rates: 8 kHz, 16 kHz
Audio encoding: G.726 ADPCM at 32 kbit/s (narrowband); G.722 (wideband); later editions add G.729.1 and LC3plus

Audio: Speech band, not programme audio, and that is the point to take away: a beltpack link is built to carry a voice intelligibly, not to carry a mix. EN 300 175-8 names the codecs and each codec fixes its own rate — G.726 samples at 8 kHz, G.722 at 16 kHz for roughly 50 Hz to 7 kHz. Which are mandatory depends on the profile the product implements.

What goes wrong

Band allocation is national. 1.88–1.90 GHz in Europe and elsewhere; North America uses a different slice, so packs are not always portable between regions.

Antenna coverage is a survey problem, and handover between antennas is where a system reveals whether it was designed or hoped.

Every wireless link adds latency the wired partyline did not have — see the comms explainer for what that does to a conversation.

What speaks DECT (2)

Product	Direction	Notes
Clear-Com FreeSpeak II Clear-Com	bidirectional	The radio link to the beltpacks.
Riedel Bolero Riedel Communications	bidirectional	Radio link to beltpacks.

Typical use

Wireless intercom beltpacks on theatre, broadcast and touring shows.
Any wireless comms where the 2.4 GHz band is already full.

Sources

ETSI EN 300 175-8 — DECT Common Interface, Part 8: Speech and audio coding — ETSI primary
ETSI DECT — ETSI primary

Understand the mechanism

Sharing the airwaves Getting the crew to hear each other

Something wrong, or missing?

Known gaps on this entry: default_ports, implementations. If you can source one of them, that is a ten minute pull request.

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