LoRaWAN Passive Roaming vs. Handover Roaming: Key Differences

This page compares LoRaWAN Passive Roaming vs. Handover roaming and highlights the differences between them.

Image Alt: LoRaWAN Architecture in roaming mode

The figure above illustrates the LoRaWAN architecture. As shown, a LoRaWAN system comprises an end device, a radio gateway, a network server (NS) in three modes, an application server, and a Join server.

Passive Roaming

Image Alt: LoRaWAN Packet transmission using passive roaming

• In this roaming type, the LoRaWAN Session and the MAC-layer control of the End-Device are maintained by the serving NS (sNS).
• Frame forwarding to and from the air interface is managed by the Forwarding NS (fNS).
• In passive roaming, there can only be one serving NS for a given LoRaWAN Session, whereas zero or more forwarding NSs may be involved with the same session.
• The figure above depicts the message flow for a Passive Roaming Procedure between two NSs for an ongoing LoRa Session of an End-Device.

Handover Roaming

Image Alt: LoRaWAN Handover Roaming Start

• It enables the transfer of MAC layer control from one network server to another NS.
• The hNS interface maintains the control-plane and data-plane with the JS and the AS even after the End Device performs a Handover Roaming from one NS to another.
• The hNS interface remains the same for a given LoRaWAN Session until the End Device performs the next Join Procedure.
• Unlike the forwarding NS, the serving NS has the capability to control the End Device RF settings, which allows for more flexible roaming scenarios.
• The figure above shows the message flow between the end device, NS2, NS1, and JS (Join Server).

Difference between Passive Roaming and Handover Roaming in LoRaWAN

The following table highlights the key differences between Passive Roaming and Handover Roaming.

Image Alt: LoRaWAN Difference between Passive Roaming vs Handover Roaming

Reference: LoRaWAN Backend Interfaces document V1.0, available for download at www.lora-alliance.org.