Passive roaming LoRaWAN® packets
This topic describes reference information about passive roaming LoRaWAN® packets.
Passive roaming is a mode by which a device can seamlessly roam away from home and uses base stations of the visited network - connected to a forwarding network server (fNS) - to reach its home network.
The following terminology is used in passive roaming mode:
A serving network server (sNS) or home network server (hNS) is where the device is provisioned. sNS manages the interface with the device's application server. A serving network server may receive the same uplink packet via different base stations, even with a mix of local base stations (belonging to this home sNS) and foreign base stations (belonging to roaming partners). In this case, the best gateway of this uplink packet is the one receiving it with the highest SNR.
A forwarding network server (fNS) is an intermediate network server used as a bridge between the device and the serving network server. It forwards the LoRaWAN® packets between the device and the sNS when the device roams in a zone covered by the base stations of the visited network.
The serving and visited networks must have a roaming agreement in place.
Passive roaming packets
To learn more about the different icons used in the scope of passive roaming, see Passive roaming icons.
On the visited network (fNS), LoRaWAN® uplink/downlink packets of foreign devices (doing roaming-in) are displayed on the Wireless Logger only if the related best gateway of the uplink packets belongs to your account. This allows the base station managers of the visited network to monitor all the traffic routed through their base stations, including roaming traffic. Nevertheless, for sake of payload confidentiality, the device's applicative payloads are hidden by the system.
On the home network (sNS), LoRaWAN® uplink/downlink packets of your roaming-out devices attached to your account are displayed in Wireless Logger. This allows the device manager to monitor all the LoRaWAN® traffic of their devices whatever they are at home or roaming-out on other networks. If an uplink packet is received by both fNS and sNS, then the packet is displayed on the Wireless Logger account of the best-LRR (having the highest uplink SNR among all the receiving base stations).
Passive roaming metadata
The uplink metadata described in Uplink metadata columns and Uplink expandable panel are still valid for passive roaming traffic. Same thing for downlinks: see Downlink metadata columns and Downlink expandable panel.
Additionally, the following roaming-specific metadata is supported by Wireless Logger:
- GWID or Best gateway ID: identifier of the gateway belonging to the forwarding network. In case the same uplink packet has been received by the sNS via several foreign gateways, the "Best gateway ID" corresponds to the foreign gateway elected as best-LRR by the sNS.
- Gateway token: the gateway token provided by the forwarding NS (fNS) in the PRStartReq metadata. It corresponds to the FNSULToken specified in LoRaWAN backend interfaces specifications TS002.
- Foreign Operator NetID: the NetID of the forwarding network. This information is only filled if the network server acts as a serving network server (sNS) and the best base station is a foreign one (not belonging to the device's home network).
- Foreign Operator NSID: the NSID of the forwarding network. This information is only filled if the network server acts as a serving network server (sNS) and the best base station is a foreign one (not belonging to the device's home network) and both fNS and sNS peers using v1.1 (or higher) of the LoRaWAN backend interfaces specification TS002.
- Roaming type:
- 0 for fNS passive roaming (i.e. foreign traffic roaming-in to my base stations)
- 1 for sNS passive roaming (i.e. my devices roam-out through my partners)
- Roaming result: The PRStartAns (for uplink packets) or XmitDataAns (for downlink packets) result code, as specified in LoRaWAN backend interfaces TS002 section 23.5. For uplink packets, this result is generated by the sNS after the uplink deduplication window.
- DLAllowed: Filled by the forwarding NS (fNS) in the PRStartReq metadata, it corresponds to the DLAllowed boolean specified in LoRaWAN backend interfaces specifications TS002 by which fNS indicates to sNS if a downlink transmission is possible in response to this forwarded uplink packet.