What is Single Pair Ethernet (SPE)?

Single Pair Ethernet (SPE) is an Ethernet technology that uses a single twisted pair of wires to transmit data and power simultaneously. Unlike traditional Ethernet, which typically requires four pairs of wires (eight conductors), SPE simplifies networking infrastructure while maintaining high data speeds and long transmission distances. It is widely used in industrial automation, automotive, and IoT applications.

SPE differs from traditional Ethernet in several ways:

• Fewer Wires: Uses only one twisted pair instead of four, reducing cable weight and cost.
• Longer Distance: Supports data transmission over up to 1,000 metres, compared to standard Ethernet’s 100 metres.
• Power and Data Combined: Can deliver power over the same cable using Power over Data Line (PoDL), eliminating the need for separate power cables.
• Optimised for IoT and Industrial Use: Ideal for industrial automation, automotive, and embedded applications where space and weight constraints are critical.

• Cost-Effective: Reduces cabling costs and simplifies network infrastructure.
• Lightweight and Space-Saving: Ideal for compact applications such as automotive and robotics.
• Supports Long Distances: Can transmit data up to 1,000 metres, depending on the standard used.
• High-Speed Data Transmission: Supports speeds up to 10 Gbps in short-range applications.
• Power Delivery: Enables devices to receive both power and data over a single pair of wires.
• Improved Reliability: Fewer wires mean fewer failure points, improving network stability.

SPE is widely used in:

• Industrial Automation – Connecting sensors, controllers, and actuators in smart factories.
• Automotive – Used in modern vehicle networks to replace heavier legacy cabling.
• Building Automation – Smart lighting, security, and HVAC systems.
• Rail and Transportation – Lightweight networking for trains and aircraft.
• IoT (Internet of Things) – Connecting edge devices in smart cities and manufacturing.

Single Pair Ethernet can support multiple data rates, including:

• 10 Mbps (for distances up to 1,000m)
• 100 Mbps (for distances up to 400m)
• 1 Gbps (for distances up to 40m)
• 10 Gbps (for ultra-short-range applications)

The speed and distance capabilities depend on the specific IEEE standard being used.

SPE is governed by several IEEE 802.3 standards, including:

• IEEE 802.3cg – 10BASE-T1 (10 Mbps over up to 1,000m)
• IEEE 802.3bw – 100BASE-T1 (100 Mbps over up to 40m)
• IEEE 802.3bp – 1000BASE-T1 (1 Gbps over up to 40m)
• IEEE 802.3ch – 2.5GBASE-T1, 5GBASE-T1, and 10GBASE-T1 (short-range high-speed applications)

Yes.  Power over Data Line (PoDL) is an SPE feature that allows devices to receive both power and data over a single twisted pair, much like Power over Ethernet (PoE) in traditional networks. This eliminates the need for separate power wiring, reducing installation costs.

SPE requires dedicated switches, connectors, and adapters to integrate with traditional RJ45-based Ethernet networks. However, media converters and gateways can bridge the gap between SPE and standard Ethernet.

The industry has adopted IEC 63171-6 and IEC 63171-2 as the standard connector types for Single Pair Ethernet. These connectors are:

• Compact and robust
• Designed for industrial and automotive environments
• Compatible with existing infrastructure through adapters

The maximum transmission distance depends on the data rate:

• 10 Mbps – Up to 1,000 metres
• 100 Mbps – Up to 400 metres
• 1 Gbps – Up to 40 metres
• 10 Gbps – Short-range applications only

SPE is not designed to replace traditional multi-pair Ethernet but rather to complement it, especially in industrial, automotive, and IoT environments where weight, space, and long-distance transmission are critical factors. Standard Ethernet will still be used in high-performance computing, office networks, and data centres.

• Reduces cabling complexity in factories and smart buildings.
• Enables direct connectivity between sensors, actuators, and controllers without additional gateways.
• Supports real-time communication for industrial applications.
• Power over Data Line (PoDL) eliminates the need for separate power wiring.

• Replaces bulky wiring harnesses in vehicles, reducing weight and improving fuel efficiency.
• Supports advanced driver-assistance systems (ADAS) and autonomous driving.
• Enables high-speed communication between ECUs, sensors, and cameras.
• Simplifies network topology for next-generation vehicle architectures.

Yes.  SPE is gaining widespread adoption across industries due to its efficiency, cost-effectiveness, and long-distance capabilities. With growing support from networking manufacturers, industrial automation companies, and the automotive sector, SPE is expected to play a significant role in the future of industrial IoT and vehicle networking.

• IEEE 802.3 Standards: https://standards.ieee.org
• SPE Industrial Partner Network: https://singlepairethernet.com