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Cellular (NB-IoT and LTE-M)

NB-IoT and LTE-M are cellular technologies built for IoT rather than for phones. They use a network that already exists, so there is nothing to deploy beyond a SIM, and they are designed to reach indoors and into basements. NB-IoT suits metering and static sensors; LTE-M supports movement and faster transfers, which suits trackers. The radio side is covered under Cellular IoT.

How it differs from LoRaWAN​

With LoRaWAN a network server sits between the device and Yggio and standardises the handover, so one connector serves every device on that server. Cellular has no equivalent. The device gets an IP connection from the operator and then speaks whichever protocol its manufacturer chose, straight to Yggio.

That has two consequences worth planning for:

  • The integration is per protocol, not per operator. Your SIM supplier is not part of the Yggio configuration.
  • Devices arrive as Generic devices, identified by a unique identifier such as the IMEI, rather than by a LoRaWAN DevEUI.

Choose a protocol​

Which of these a device supports is decided by its manufacturer, not by you. Where there is a choice, MQTT is the best supported path and by some margin the easiest to troubleshoot.

ProtocolConnectorDirectionNotes
MQTTMQTTIn and outPublish on the platform broker or an external one
CoAPCoAPInCompact request/response, designed for constrained devices
UDPUDPInRaw datagrams, for devices that offer nothing higher
HTTPPart of GenericInThe device posts to /http-push/generic

Direction matters here more than with LoRaWAN, because only MQTT carries anything back to the device. On CoAP, UDP and HTTP the device reports and Yggio listens, so if the device has to be configured or commanded remotely, that has to be planned for separately.

Some manufacturers have their own connector rather than a generic one. Celsiview and Elvaco CME are both cellular and both have a dedicated connector; see Connectors.

Setting a device up​

The Yggio side is short. The device side is not, because a cellular device has to be told how to reach the mobile network before it can reach anything at all, and that is done with AT commands over a serial or Bluetooth console rather than a graphical interface.

Connecting NB-IoT Devices walks the whole path in order: the credential set and reserved topic in Yggio, the SIM, the console, the network attach, and the connection to Yggio, with one widely used sensor family as the worked example. The mobile-network steps apply to any device built on a common NB-IoT module.

Set aside more time than you expect for the first device. Once one is working the rest are quick, since most devices can load a saved configuration rather than being typed in command by command.

When it does not attach​

Change one setting at a time, and work from NB-IoT Troubleshooting rather than from the device manual. The failures worth knowing about are the common ones: an ordinary mobile broadband SIM instead of an NB-IoT SIM, the wrong APN, and a band or operator lock left over from a previous deployment.