Time-sensitive networking explained: Guaranteed performance for mission-critical applications

Time-sensitive networking explained: Guaranteed performance for mission-critical applications 

Time-Sensitive Networking (TSN) represents one of the most significant developments in modern Ethernet technology. Defined by a set of IEEE 802.1 standards, TSN enables the creation of communication networks that are not only high-speed but also deterministic, reliable, and synchronised to sub-microsecond precision. In this insight piece, we explain the meaning of TSN and how it works. 

At its core, TSN builds on the Institute of Electrical and Electronics Engineers (IEEE) 1588 Precision Time Protocol (PTP), a well-established standard that allows devices within a network to synchronise their clocks to a master timing source. This foundation ensures that data transmitted across the network is delivered on time, in order, and with confirmation of completeness. 

What is time sensitive networking? 

TSN builds on networking approaches such as HSR or PRP, and the time synchronisation of PTP, to enable schedulers and traffic shapers to be combined so hard real-time, soft real-time and best-effort traffic can coexist. 

In the context of TSN, reliability means that every packet must arrive intact, redundancy ensures resilience even when data must be sent multiple times, and determinism provides confidence for how and when information is received. Latency reduction is also another essential factor, ensuring that data flows seamlessly across systems that cannot afford delays.  TSN is therefore an enabler for communicating hard real-time, deterministic traffic over Ethernet networks. 

Defence platforms, industrial automation systems, and even transportation infrastructure demand not just connectivity, but assured connectivity. TSN means that data is moved around reliably between nodes and ensures that information from various sensors can be fused faster and more accurately, speeding up decision cycles. 

TSN in defence and critical industries 

From a defence perspective, TSN offers an ideal path to replacing legacy communications such as CAN bus, Modbus, and RS-232/485. These established methods have provided deterministic communications for decades, but they are limited in bandwidth, largely copper-based, and increasingly unsuited to modern multi-domain requirements.  

Ethernet over fibre, supported by TSN, offers a smaller, lighter, and secure alternative. Fibre cabling reduces weight and volume and is less susceptible to electronic interference and hostile action (such as electronic attack), enabling longer transmission distances without the need for frequent repeaters. This makes it ideal for surface and underwater platforms, armoured land vehicles and aircraft, as well as other platforms where copper-based cable runs impact space and weight. 

Similarly, in new-generation vehicles and aircraft, fibre-based TSN networks provide the scalability and robustness required for decades of service. 

Defence platforms also have to operate in extreme environments, whether that is very high or low temperatures, as well as shock and vibration that is often associated with military operations. A TSN solution therefore has to meet a variety of stringent ruggedisation standards such as those from the US Department of Defense and NATO. 

TSN is not limited to defence with deployments seen in a range of other sectors, including civil aerospace, industrial automation, broadcasting, and telecommunications. The challenges of vibration, temperature extremes, and ruggedisation in these industries mirror those in defence, making rugged TSN solutions highly transferable and broadening the supply chain for future proofing.  

In some cases, domain TSN “standards” have been agreed through bodies such as SAE and IEEE working-groups and these build-on, or pick-from, the existing standards, to further interoperability.  Such standards enable vendors to invest in implementing TSN on new or upgrade programs, with more certainty. 

Concurrent’s leading rugged TSN solutions 

Concurrent is a leading expert in TSN and this technology is embedded across its product portfolio. The company has made a commitment that all new and future products will include Ethernet with TSN standards support, positioning itself at the forefront of adoption. This integration covers both board-level and system-level products, ensuring that TSN is not an add-on feature but a core capability. 

Concurrent’s Hermod II rugged switching system exemplifies this approach. Designed as a rugged, 1G and 10Gb  TSN Ethernet Switching System, it features a mix of 10Gb optical and 1G copper ports, and can operate links with TSN standards-support or as a ‘best-effort’ Ethernet device, making it versatile for multiple deployment scenarios.  

Its ruggedisation allows it to meet the survivability requirements of military platforms, where exposure to extreme environments, vibration, and shock is unavoidable. Hermod II is particularly relevant in scenarios where networking extends beyond an internal backplane, linking line-replaceable units (LRUs) across platforms such as tanks, helicopters, or other mission-critical systems.  Hermod II units are passively cooled with no moving parts and have MIL-38999 connections for operations in harsh environments. 

At board level, Concurrent’s 3U VPX portfolio aligns with OpenVPX and SOSA standards, delivering dual- and single-enclave Ethernet switches as well as processor cards with TSN capability. This integration enables utilisation of TSN standards across multiple units inside a larger platform, mixing traffic types and priorities as needed to fulfil the mission.  By having a reconfigurable switch based on FPGA technology, if TSN standards change then so can the Concurrent HW.  This protects investment in the initial purchase and extends the service life of equipment as well as enabling potential adaptations to be more quickly realised, should the changing threat landscape require them. 

Cutting-edge TSN solutions 

Edge computing is another area where TSN plays a vital role. While ultra-low-latency networks theoretically allow data to be sent to centralised cloud facilities, the limitations of security, cost, and bandwidth mean that processing must still be carried out at the edge.  

Defence platforms such as UAVs or helicopters cannot beam gigabits of data to ground stations without added cost and vulnerability. TSN ensures that these edge environments can support secure, deterministic communication while reducing reliance on external connectivity. 

The transition from copper to fibre in both defence and industrial settings will further accelerate TSN adoption. Copper remains sufficient for short-range or legacy systems, but fibre’s advantages are overwhelming for new builds.  

TSN and the modular open systems architecture (MOSA) 

TSN’s role within the broader context of modular open systems architecture (MOSA) and SOSA standards is equally important. By adopting open standards, equipment manufacturers reduce vendor lock-in and ensure interoperability across suppliers. TSN supports this vision by providing a recognised, standardised approach to deterministic networking that can be implemented consistently across products and systems. 

Concurrent’s proactive integration of TSN into its board and system-level offerings positions the company to capitalise on this, providing both the rugged hardware and the standards compliance needed for adoption. 

Summary 

Time-Sensitive Networking is not simply an incremental improvement to Ethernet, it is a fundamental enabler of reliable, deterministic, and ruggedised communication across defence, aerospace, transportation, and industrial domains. 

Concurrent’s investment in TSN across its product portfolio, led by innovations such as the Hermod II 10 Gigabit ethernet switching system and its SOSA-aligned VPX range, ensures that it is well positioned to support customers as they transition to the next generation of networking.  

TSN is more than a technical enhancement; it is a strategic necessity for future-proofing critical systems in environments where failure is not an option.