Multicast & Broadcast in 5G (MBS) introduces native point-to-multipoint delivery into 5G New Radio (NR), standardised from 3GPP Release 17 onwards, and is integrated directly into the 5G Core and Radio Access Network (RAN). Delivery can be point-to-multipoint (PTM), one transmission shared by many devices, or point-to-point (PTP), a separate copy per device, with the network choosing between them. This enables efficient distribution of identical content to many devices simultaneously, whether for live TV, emergency alerts, or software updates.
The Problem It Solves
Sending the same content to a stadium full of devices as separate unicast streams consumes network capacity proportional to the audience size, however large it gets. MBS avoids that by building multicast and broadcast directly into the 5G Core and RAN: the network can choose point-to-multipoint delivery, one transmission reaching every device at once, instead of a per-device copy. That is what makes live TV, emergency alerts and mass software distribution practical at any audience size, without capacity scaling with the number of receivers.
The project at a glance
What it is, how it works, and where the Reference Tools stand, in one deck you can share.
Download the deck (5G Multicast Broadcast Services (MBS))From idea to running code
Read it, check it against the standard, then run it.
Technical Analysis
How this technology works, and what it is good for.
Specifications
The specifications this technology is built on.
Software Accelerator
The open-source software that implements it.
Latest updates and roadmap
Status on 23 October 2026
reports in progress
- Service and System AspectsTechnical Report on MBS: Service and System Aspects.
- Service Layer AspectsTechnical Report on MBS: Service Layer Aspects.
- RAN AspectsTechnical Report on MBS: RAN Aspects. Further reports cover mobility, RAN procedures and NTN.
in development
- MBS Broadcast demonstrationAn end-to-end MBS Broadcast demonstration: 5GC, MBSF, MBSTF, gNB and UE, with DASH over broadcast.
- Closer to the specificationsCompliance work on the MBSF, the MBSTF, the MBS Client and the application and provider tools.
- Broadcast in the RANMore robust MBS Broadcast reception in the UE and the gNodeB, including concurrent sessions.
released
- rt-mbs-examples v0.4.02 Oct 2026. Docker set up for MBS User Services, loadable demo templates and a non-interactive tutorial mode.
- rt-mbs-function 1.1.03 Jul 2026. Support for the Packet Distribution Method for MBS Distribution Sessions.
- MBS gNodeB v0.1.4-5mbs-srsRAN_Project14 Jul 2026. MBS support across the gNodeB: broadcast session setup and delivery.
Merged since 9 Jun 2026 40 pull requests in 8 repositories
Standards Implemented
See Media delivery over 5G Multicast Broadcast Services: Specification list for version history and 5G-MAG's own standards contributions.
Open Source, Built Together
Repositories of This Project
The real, running software for this technology: what each repository is, what it implements, its latest release and where to find it.
Early Access: available to members first
rt-mbs-functionrt-mbs-examplesrt-mbs-transport-functionAlso used by 3GPP RAN and Core Platforms
rt-5gc-service-consumersopen5gsAlso used by Content Delivery Protocols and Tools
rt-libfluteJoin the Effort
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