An open reference implementation of the NR+ protocol stack. From the community, for the community.
What is NR+?
NR+, formally DECT-2020 NR, is a radio interface technology specified by ETSI in the TS 103 636 series of standards. Since late 2021, the ITU-R recognizes it as part of the IMT-2020 (5G) family for fulfilling the requirements for the mMTC and URLLC usage scenarios. The technology serves a wide variety of use cases, powering large-scale, high-density network deployments as well as cable-replacement solutions for mission-critical applications.
Massive IoT
Machine-Type Communications
- Up to 1 million devices/km²
- Years-long battery life for low-power sensors
- Non-IP and IPv6 traffic
- Mesh networking
- Random-access operation
Ultra-Reliable
Low-Latency Communications
- Sub-millisecond air-interface latency
- 99.999% reliability target
- Scheduled access for bounded latency
Decentralized by Design
Unlike 3GPP cellular communication networks, NR+ does not rely on centralized infrastructure and uses context-based rather than fixed device roles. In addition to the flexibility of nomadic ad-hoc deployments, users benefit from low costs and reduced operational complexity, as networks can be deployed and maintained independently of a mobile network operator.
"DECT-2020 NR as a technology foundation is targeted for local area wireless applications, which can be deployed anywhere by anyone at any time. The technology supports autonomous and automatic operation with minimal maintenance effort."
— ETSI TS 103 636-1
Wide Spectrum Access
Beyond IMT and ISM bands, NR+ has access to license-exempt spectrum in the 1880–1930 MHz range, parts of which are assigned exclusively to DECT technologies in many markets. EU Implementing Decision 2025/2425 harmonizes shared use of the 3.8–4.2 GHz band, opening it to future NR+ deployments subject to national assignments.
Flexible Network Topologies
NR+ supports point-to-point links, star networks, and mesh topologies in the form of clustered trees, covering a wide range of use cases, from wireless professional audio to large-scale IoT sensor deployments.
Protocol Stack Architecture
Opener implements the MAC and upper layers of the NR+ protocol stack. Hover over each layer to learn more.
Application Profiles
ETSI TS 103 874 series
Convergence Layer
ETSI TS 103 636-5
Data Link Control
ETSI TS 103 636-5
Medium Access Control
ETSI TS 103 636-4
Physical Layer
ETSI TS 103 636-3
Explore the Stack
Hover over any layer to see detailed information about its functionality and key features.
Guiding Principles
Learn about the core principles that guide the development of Opener and shape the project's technical vision.
Ready for commercial use
Opener not only fosters academic research but is also suitable for integration into demanding commercial products. For this reason, we chose the Apache 2.0 license for the project. Apache 2.0 is a business-friendly, OSI-approved permissive software license with no copyleft provisions that restrict commercial use. In addition to broad usage rights, Apache 2.0 includes an express grant of patent rights from contributors, providing legal protection and peace of mind for adopters.
Application- and vendor-agnostic
Opener addresses the needs of applications across various domains and use cases, ranging from building automation or smart metering to professional audio. Built for Zephyr, the RTOS adopted across the NR+ integrated hardware ecosystem, Opener is not tied to a specific silicon vendor or instruction set architecture. Where sensible, its design remains mindful of portability to other operating systems.
Interoperable and standards-compliant
Opener complies with harmonized European norms and targets to pass ETSI-defined conformance tests.
How to Contribute
The Opener Initiative is a growing community for technical exchange around NR+ and stack development, and we aim to keep the barrier to participation low. Whether you're a seasoned wireless engineer or just getting started, there's a place for you.
Get Started
Ready to join the open NR+ revolution? Here's how to get started.
Standards Documents
Read the DECT-2020 NR specification, the ETSI TS 103 636 series that defines the protocol Opener implements.
Source Code
Clone the Opener repository. Report issues, open pull requests, and try the sample applications.
Proposals
Explore the ideas shaping the stack's direction, and help refine them before they become code.
What's New
Follow along as the open NR+ stack takes shape.
DECT World 2026 Pre-Event: Getting Started with NR+
Join us on November 2, 2026 in Munich for a free hands-on afternoon and evening that gives you a practical entry point into the DECT NR+ ecosystem — organized by the OPENER Initiative and hosted by the DECT Forum.
DECT NR+ at the RIOT Summit and Ariel OS Community Day in Grenoble
Grenoble, France. The place where the open-source IoT community meets. And DECT NR+ finds space on the programme twice. From 1 to 3 September, two events share the same rooms at Polytech Grenoble: the Ariel OS Community Day and the RIOT Summit. Christian Amsüss speaks on both. On Tuesday about the implementations, on Wednesday about the technology itself.
Who builds OPENER — and why?
DECT NR+ is a technology. A standard, a specification, a promise on paper. And what it becomes is decided by the people who start writing real code.