Comparison
ASG vs Automotive Ethernet
Automotive Ethernet brings switched IP networking to the vehicle backbone; ASG is a control architecture, not a transport, delivering deterministic vehicle-wide state without switches or a protocol stack.
StandardIEEE 802.3 physical layers (100BASE-T1, 1000BASE-T1, 10BASE-T1S) with 802.1 TSN for scheduling. OPEN Alliance profiles.
Automotive Ethernet is the right answer for moving a lot of data. A camera feed or a software update belongs on a gigabit link, not a control bus.
Where the two overlap is control. Ethernet can carry control traffic, and with TSN it can bound the latency, but only if the schedule is designed and enforced across every switch. That is the part ASG does not ask of the integrator.
At a glance
Point-to-point links into switches, carrying IP. Bandwidth for cameras, lidar and the zonal backbone, with middleware such as SOME/IP or DDS providing the service model.
Not a transport. A synchronous control layer where the vehicle state itself, not a stream of packets, is the shared object, committed every millisecond.
Topology
How they differ
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Determinism
Automotive EthernetBest-effort by default. Bounded latency needs 802.1 TSN configured and enforced on every switch in the path; without it, queueing under load spreads the tail.
ASGBounded by construction. Every event is on the 1 ms grid at every load, with nothing to configure.
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What is shared
Automotive EthernetPackets. A shared view of the vehicle is built by middleware such as SOME/IP or DDS on top of the network.
ASGState. Every module holds the same committed state vector each millisecond; there is no middleware layer to assemble it.
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Acting on many outputs at once
Automotive EthernetEach actuator is addressed by its own message. Even scheduled with TSN they are sent in sequence and arrive close together, not together.
ASGEvery output in a control group is committed in the same 1 ms instant, by construction. This is what makes coordinating many moving parts direct rather than a timing problem.
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Infrastructure
Automotive EthernetSwitches, PHYs, a full IP stack per node, and TSN configuration and monitoring.
ASGNo switches and no stack. Zones on a ring, plus the real-time OS.
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Wiring
Automotive EthernetA dedicated pair per device back to a switch; the switch fan-out and its power add harness back.
ASGOne ring carrying power and data; roughly 200 to 300 m per vehicle in ASG’s own figures.
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Speed versus certainty
Automotive EthernetVery low latency for a single message on a lightly loaded link, often lower than ASG.
ASGNot the lowest peak latency, but the same latency every time, which is what a control loop needs.
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Fault handling
Automotive EthernetA link fault is isolated by the switch; there is no actuator-level protection in the network itself.
ASGEach block self-protects in about 10 microseconds, replacing relays.
Common ground
The matrix
| Dimension | Automotive Ethernet | ASG |
|---|---|---|
| What it is | A transport. IP networking for high-bandwidth links and the backbone. | A control architecture: protocol, real-time OS and ring channel as one system. |
| Topology | Point-to-point links into switches; a star, or a ring of switches for the backbone. | Single ring routed through the vehicle volume; zones attach within a wire-length budget. |
| Medium | Dedicated single differential pair per link (100BASE-T1). Power routed separately, or PoDL. | Power and data on the same conductors (PLC over 12 / 24 / 48 V), or a twisted pair. |
| Media access | Full-duplex point-to-point, so no media contention; queueing happens inside the switches. | Frequency-division. Each zone has its own carrier (a diad); no contention for the channel. |
| Timing model | Asynchronous by default; bounded only where 802.1 TSN scheduling is added and configured. | One global commit every 1 ms. Every zone updates in the same instant. |
| Determinism under load | Best-effort unless TSN is deployed end to end; switch queueing spreads the tail under load. | Fixed. Every event lands on the 1 ms grid regardless of how many zones or events. |
| Raw data rate † | 100 Mbit/s (100BASE-T1) to 1 Gbit/s (1000BASE-T1) and beyond; 10 Mbit/s for 10BASE-T1S. | ~2.7 Mbps on the shared channel; capacity added by carriers, not by frame time. |
| Vehicle-wide state | None inherent. State is whatever the application layer (SOME/IP, DDS) builds on top. | Native. Every module holds the whole committed state vector each millisecond. |
| Compute model | Sequential per ECU; typically a few large compute nodes plus the network. | Distributed and time-parallel: every module computes on the same state in the same window. |
| Harness impact † | A dedicated pair per device to a switch; switch fan-out adds harness back. | One ring carrying power and data. ~200-300 m of wiring per vehicle in ASG's own figures. |
| Fault handling | A fault is contained to one link; the switch isolates it. No inherent actuator-level protection. | 10 us local reaction in each block acts as an electronic fuse; no relays needed. |
| Standardisation & maturity | IEEE 802.3 / 802.1. Mature IT base; automotive profiles and TSN still consolidating. | ISO-compliant seven-layer protocol; pre-series. Standard number and assessments still to be cited. |
| Tooling & ecosystem | Large and growing, drawing on the wider IT and networking industry. | Early. A public simulator; silicon, stacks and test tools are in development. |
† derivation still to be confirmed. Legacy figures are the nominal values from the published standards; ASG figures are set out on the methodology page.
Where Automotive Ethernet is the better choice today
- Bandwidth
Nothing else here is close. Gigabit links for sensors and the backbone are Ethernet’s core job, and ASG does not attempt it.
- IT ecosystem
Decades of silicon, stacks, security tooling and engineering talent transfer directly from the wider networking industry.
- Standards momentum
IEEE and the OPEN Alliance are actively developing automotive Ethernet and TSN; it is where most new backbone investment goes.
- Raw single-message speed
On a quiet link Ethernet can deliver one event faster than ASG’s 1 ms. ASG trades that peak for an invariant.
Questions
Doesn’t TSN already make Ethernet deterministic?
TSN can bound latency, but only when its schedule is designed and enforced on every switch in the path, and re-validated when traffic changes. ASG’s bound is fixed and needs no per-network configuration.
Should a vehicle use both?
Usually yes. Ethernet for cameras, lidar and the data backbone; ASG for the control layer underneath. Where control signals ride on Ethernet today, a zone module can terminate that link and fold them into the shared vehicle state directly, with no gateway in between.
Is ASG slower than Automotive Ethernet?
For a single message on a lightly loaded link, often yes. For a control system the useful property is that the 1 ms never varies, at any load, which switched Ethernet cannot promise without TSN everywhere.