Mobility in LoRaWAN

In many IoT applications, mobility is a major parameter to consider. For example, in healthcare, monitor patient, tracking objects, etc.
Is LoRaWAN technology applicable for such applications? Do LoRaWAN supports movement of the node between different Gateways?

nodes don’t ‘connect’ to gateways like wifi
So yes… you can move around and gateways in reach will receive and forward the node’s signal… the network backend decides which gateway will answer (when neccesary)

In LoRaWAN we have uplink which is the message sent from device to Application server, and downlink which is the message send from Application server to device. How Network server can detects the place of this device during mobility?

strongest signal and time of arrival

Thank you, so this depend on the next uplink received.

uhhh I don’t follow you :sunglasses:

LoRaWAN Class A only allows for downlinks after an uplink. For Class B and C another mechanism will be required to select the best gateway. It will be interesting to see how this is/will be implemented in networks supporting Class B and C.

1 Like

This means that only classes B and C support mobility? Or did each class support mobility using a different mechanism? Does mobility between different network servers support LoRaWAN?
Example: If a device of class A, B or C leaves the gateway coverage belonging to the network server X, to an area covered by gateways belonging to the network server Y. Does LoRaWAN support roaming between different network servers? If so, what is the communication mechanism used by this device to get a connection?

No. Class A supports mobility. Class B and C will have more issues with mobility.

I suggest you read up on the LoRaWAN 1.1 standard. Also check the TTN YouTube channel, specifically watch https://m.youtube.com/watch?v=ewsXKc3bk1U

2 Likes

…because the downlink will happen 1 second (RX1) or 2 seconds (RX2) after an uplink, and in such a short time a device should not move out of reach of the gateway(s) that received the uplink.

Yes, With LoraWAN, end-devices “join” with the server and not with the gateway. The end-device can be heard by several gateways and that data will be passed on to the server.

In Wi-Fi, the mobile station authenticates and associates with one access point at a time.

Thank you for your response.

Message drop occurs on Gateway or Network server?
Example: Case of an End-Device corresponds to Network operator X, and due to the movement, GWs of Network operator Y receives the message. Consider no roaming, are the GWs check for the End-Device identity and drop. Or GWs just forward the message and at Network Server and check on identity is done and the message is dropped?

Usually the network servers are the one that drop the packets, But gateways can also be configured to drop pckets that do not belong to the network.

1 Like

Thanks for your clarification.
LoRaWAN v1.1 supports two types of roaming, passive and handover. In the case of passive roaming, the LoRaWAN device can move between two or more network operators. This movement is transparent to the LoRaWAN device. Therefore, even if the device is outside the coverage of the home network operator, the device will be able to send the data and the new operator of the network will send the data to the home NS of the device. Of course, the two network operators are in a collaboration between them. In the case of passive roaming, the new NS will function as a gateway for the home NS. In the LoRaWAN device, the device can request an acknowledgment for each uplink. In case this acknowledgment is not received, the device will repeat the uplink. My question:
In the case of passive roaming, which server (Home NS or visited NS) returns an acknowledgment (ACK) for the ED upon receiving the uplink
? Or is the ACK returned by GW correspond for the visited NS directly to ED?

Hello. I found this topic relevant for my application. How the LoRaWAN will work if the ‘Thing’ move from one country to another, most likely changing the operator as well? As far as I can see there is no global roaming manifest for the LoRaWAN members. Could someone point me to a proper documentation on this? There are reasons why I look into LoRa rather than Sigfox and cellular. Thanks in advance.

see discussion here

important is, that the country you enter with your mobile device, has the same frequency-plan used in your device, if not, it won’t be heared by the local TTN gateways.

Differently from cellular networks, it is not obvious that networks are country-specific. If you are on TTN, it is just matter of having gateways around you (and, as pointed out by BoRRoZ, with the same frequency plan). If you are on a private network, there is some possibility of roaming, in the future, through PacketBroker.

Thanks for a quick reply. Will look into this.