Power-over-Ethernet for Outdoor Node Deployments

Power over Ethernet (PoE) is an excellent choice for outdoor nodes at sites with structured cabling infrastructure. It combines power delivery and network connectivity in a single cable, simplifying installation and enabling remote management.

PoE Standards

For mesh nodes, IEEE 802.3af is more than sufficient. Most nodes consume 1-5W.

PoE for Raspberry Pi Room Server + LoRa Node

A Pi-based room server with an attached LoRa radio is a common configuration that benefits significantly from PoE:

Architecture:
PoE Switch --> Cat5e/6 cable --> PoE HAT on Raspberry Pi
                                 Pi runs MeshCore room server
                                 Pi connected via USB to LoRa radio node

Recommended PoE HAT options:

• Official Raspberry Pi PoE+ HAT — $20, up to 25W, built-in fan, fits Pi 3B+/4/5
• Waveshare PoE HAT (B) — $15, 15W, quieter than official HAT

Maximum Cable Run Distance

PoE follows the Ethernet 100m (328 ft) cable run limit. For outdoor nodes at distances greater than 100m from the PoE switch:

• Use a PoE extender (repeater) at the 100m mark to extend another 100m
• Use fiber optic run (with media converter) for runs over 200m — eliminates lightning coupling between building and node
• Use cellular or WiFi for power-independent remote nodes

Lightning Protection for PoE Runs

An Ethernet cable run to an outdoor node creates a lightning risk — the cable can couple surge energy into your equipment:

• Ethernet surge protector: Install a PoE-compatible Ethernet surge protector (Ubiquiti ETH-SP-G2, $15) at both the building entry and the outdoor node enclosure. This is essential for any outdoor Ethernet run.
• Fiber optic break: Insert a fiber optic run between the building and the outdoor node. Fiber is dielectric — it cannot carry surge current. Best protection option.
• Grounding: Properly ground your outdoor enclosure and the surge protectors. Bond all ground connections to a single earth ground point.