EV In-Vehicle Network

The In-Vehicle Network (IVN) is the internal communication fabric that connects sensors, compute, controllers, and actuators inside the vehicle. Modern IVNs combine a high-bandwidth Automotive Ethernet backbone with legacy control buses (CAN/CAN-FD and LIN) for deterministic control and cost-effective I/O.

ADAS (Advanced Driver-Assistance Systems) and AV (Autonomous Vehicle) sensing increases data rates dramatically. IVN design determines whether multi-camera, radar, and LiDAR data can reach compute with the latency, determinism, and reliability needed for safe motion control.

IVN technology layers

Most vehicles run multiple network types simultaneously. Ethernet carries high-rate sensor data; CAN/CAN-FD carries real-time control and diagnostics; LIN handles low-cost low-speed devices.

Network	Primary role	Where it is used	Key hardware	Notes
Automotive Ethernet	High-bandwidth data plane	Cameras, ADAS compute, zonal backbones	Switches, PHYs, connectors, shielded cabling	100BASE-T1, 1000BASE-T1 are common; 10G-T1 is emerging for AV
CAN	Deterministic control plane	Powertrain, chassis, safety signaling, diagnostics	MCUs, CAN transceivers, gateways	Robust, mature, ubiquitous
CAN-FD	Higher-throughput CAN	Domains needing more payload than classic CAN	MCUs, CAN-FD transceivers, gateways	Often used as a bridge while Ethernet backbones expand
LIN	Low-cost low-speed bus	Body electronics, simple sensors/actuators	LIN transceivers, simple nodes	Not suitable for ADAS sensor streaming

Topology: from ECU sprawl to zonal backbones

Legacy vehicles used many discrete ECUs connected by multiple CAN buses. Modern vehicles increasingly adopt zonal architectures: ZCUs (Zonal Control Units) aggregate local I/O, and an Ethernet backbone connects zones to central compute.

• Legacy topology: many ECUs, multiple CAN segments, heavy wiring
• Domain topology: domain controllers consolidate ECUs; Ethernet begins to appear
• Zonal topology: ZCUs per physical zone; Ethernet backbone plus gateways bridge to CAN/LIN
• Central compute topology: ADAS/AV compute node(s) connected to an Ethernet switch fabric

Key hardware

IVN performance and cost are determined by physical components that scale with autonomy level and E/E consolidation.

Building block	What it does	Where it sits	Procurement notes
Ethernet switches	Routes Ethernet traffic between zones, sensors, and compute	Central gateway, ZCU, or dedicated switch modules	Port count and thermal design scale with camera count and backbone speed
Ethernet PHYs	Physical layer transceivers for 100/1000/10G-T1 links	Sensor modules, ZCUs, gateways, compute nodes	Critical for signal integrity over automotive cabling
CAN/CAN-FD transceivers	Electrical interface for CAN networks	MCUs, gateways, ECUs	High volume, mature supply chain
Gateways	Bridges traffic between Ethernet and CAN/LIN segments	Central gateway ECU or ZCU	Increasingly integrated into ZCUs and central compute modules
Connectors and cabling	Physical interconnect for power and data	Vehicle-wide	Shielding, impedance control, and weight become primary design constraints
Timing and synchronization hardware	Clocking for sensor alignment and time-stamping	Compute nodes, switches, sensors	Becomes more important as sensor fusion and distributed compute scale

Bandwidth, latency, and determinism

ADAS/AV systems need predictable end-to-end behavior. IVN design balances raw bandwidth with latency and determinism, especially for perception-to-actuation loops.

• Bandwidth: driven by camera count, resolution, frame rate, compression, and LiDAR/radar payloads
• Latency: impacts reaction time for braking, steering, and collision avoidance
• Determinism: bounded message delivery time for safety-related control

Time-Sensitive Networking (TSN)

Time-Sensitive Networking (TSN) is a set of Ethernet extensions that support scheduled traffic and bounded latency, enabling Ethernet to carry certain real-time functions previously reserved for CAN.

• Motivation: unify data plane and selected control traffic on Ethernet
• Hardware implication: switch and endpoint support for TSN features

How IVN relates to ADAS compute and ZCUs

In zonal architectures, ZCUs aggregate local sensors and actuators and connect upstream over Ethernet. ADAS compute nodes ingest sensor streams and emit commands that propagate back through the IVN to motion controllers and drive-by-wire systems.

Common interface patterns

• Camera module: image sensor plus ISP plus Ethernet PHY (or serializer/deserializer) feeding an Ethernet switch
• Radar module: ECU feeding Ethernet or CAN depending on integration and bandwidth
• ZCU: Ethernet uplink plus CAN/LIN downlinks for local I/O
• Central compute: multi-port Ethernet plus safety monitor pathways plus gateway functions (varies by OEM)

What IVN is not

IVN is internal. External connectivity is a separate stack.

• External comms: cellular (LTE/5G), GNSS, V2X, telematics control unit (TCU)
• Cloud/fleet: data ingestion, model training, OTA orchestration

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