The LoRa Alliance has expanded the LoRaWan link-layer standard with the addition of a relay specification to improve coverage in deep indoor or underground areas.

The relay specification allows for battery-operated, easy-to-deploy network coverage extensions at a fraction of the cost of adding additional gateways. This also enables the relaying of data on nearby satellite-connected LoRaWan devices.

“LoRa Alliance members identified that end users in specific markets needed to achieve full network coverage due to environmental challenges surrounding their deployments,” said Donna Moore, CEO of the LoRa Alliance. “With relay, we’re providing a standard that allows for full end-to-end communications in extremely challenging underground, metal and concrete environments where sensor signals could use a boost or redirect to reach either the gateway or end device. The new relay feature is a direct response to market needs and provides an essential building block to enable massive IoT.”

One of the first markets to adopt relay is metering in the utilities sector. Utilities represents a massive opportunity for IoT, with VDC Research estimating that worldwide LPWAN communication services revenue will reach $2.47bn by 2025. Adding relay to the LoRaWan standard to achieve coverage for even the most difficult cases, such as meters inside metal closets, strengthens LoRaWan’s market position in metering and utilities, and more broadly across key verticals including smart cities and buildings, and industrial IoT.

Using relay is suitable for any application monitoring static assets in challenging environments.

The LoRaWan standard is proven for long-range communications, however there can be physical limits to where LPWAN communications can reach, such as around turns, underground, where a signal needs to be reflected or relayed into a specific location. LoRaWan relays allow signals to go where they physically couldn’t go before.

The TS011-1.0.0 LoRaWan relay specification describes the relaying mechanism used to transport LoRaWan frames bi-directionally between an end-device and gateway or network server via a battery-operated node. By enabling relay, the device can transfer LoRaWan frames between an end device and network when there is insufficient coverage from the gateway.

This specification enables network coverage extension through a battery-operated relay and maintains compatibility with the LoRaWan link-layer standard in terms of protocol and security. The new relay nodes are battery powered and can be installed anywhere and do not require electricity or internet connectivity. This makes them an easy-to-deploy, low-cost and low-power way to extend network coverage, without needing to add additional gateways. Relay end points allow LoRaWan to provide coverage of all devices with only a nominal cost of installation.