Introduction
To efficiently integrate different technological domains and provide a single E2E deterministic data plane, the IETF DetNet working group’s recent developments are utilized. DetNet focuses on deterministic data paths that operate over Layer-2 and Layer-3 segments, providing guarantees on reordering, latency, loss, jitter, and high reliability. It creates a Layer-3 overlay data plane across various technological domains, leveraging the deterministic characteristics of each.
DetNet’s data plane architecture is divided into two sub-layers: the service sub-layer, which provides service protection and reordering, and the forwarding sub-layer, which manages traffic engineering and congestion protection (low loss, guaranteed latency, and minimal out-of-order delivery). End systems in a DetNet domain encapsulate packets based on service requirements, with edge DetNet nodes handling both sub-layers to ensure assigned functionalities, while transit nodes provide necessary Quality of Service (QoS). Although not fully standardized, the architecture also considers components like control and management planes.
The data plane of DetNet nodes is programmed to provide per-flow Quality of Service (QoS) while ensuring the mechanisms necessary to maintain a deterministic network.
Domains involved in the testbed
1. 3GPP
We deployed a 5G Standalone (SA) network using OpenAirInterface (OAI) to enhance the capabilities of next-generation wireless communication systems. This deployment emphasizes improving both network reliability and determinism, which are essential for supporting critical and time-sensitive applications.
These enhancements are under review and will be published on the website as soon as the study is released.
You can find more information about the 3GPP architecture deployed in this scenario by following this link.
2. Ethernet TSN
The Ethernet TSN domain employs advanced switching technologies to ensure deterministic networking over wired connections. Key features include IEEE 802.1Qbv for scheduled traffic and Frame Replication and Elimination for Reliability (FRER) to boost network robustness. These technologies provide high reliability and low latency, making them ideal for critical applications across industries. Our Ethernet TSN domain uses commercial devices designed to meet the demands of sectors like railway, aerospace, automotive, and industrial automation.
3. WLAN
The WLAN domain uses IEEE 802.1 TSN features to enable time synchronization and ensure deterministic latency over wireless connections. This includes the IEEE 802.1AS Generalized Precision Time Protocol (gPTP) for synchronization and IEEE 802.1Qbv time-aware scheduling to reserve time slots for critical traffic, providing precise latency control and reducing interference from non-critical traffic. The WLAN TSN implementation in the multi-domain setup is built on Intel’s technology, using Intel NUCs with AX210 Wi-Fi 6/6E chipsets.
