I recently discovered the SenseCeiver line from Round Solutions in Germany. They make sensors and gateways but the thing about the gateways is that they are tiny in size compared to others I’ve seen.
I’m just going to copy/paste direct from them here
Gateways
SenseCeiver 4-20mA - Wireless IoT Gateway for 4-20mA Sensor-Applications
4G|NB1|M1|3G|2G|GPS|4-20mA|I/O|
SenseCeiver 4-20mA exchanges data with industrial 4-20mA-enabled sensors and enables real-time transmission to the cloud. Depending on the variant, data is transmitted via mobile radio via LTE Cat NB1, LTE Cat M1, LTE 4G, 3G or 2G.
SenseCeiver 4-20mA can be configured quickly and easily and is freely programmable via the supplied Python SDK and Telit App-Zone C.
Using energy-efficient components, this easy-to-use, intuitive sensor gateway achieves very low power consumption and can even be battery/solar powered.
SenseCeiver I/O - Wireless IoT Gateway with analog und digital inputs/outputs
3G|2G|
SenseCeiver I/O exchanges data with other devices or sensors via analog and digital inputs/outputs and enables real-time transmission to the cloud. Data is transmitted via mobile radio via LTE Cat NB1, LTE Cat M1, LTE 4G, 3G or 2G, depending on the variant.
SenseCeiver I/O can be configured quickly and easily and is freely programmable via the supplied Python SDK and Telit App Zone C.
Using energy-efficient components, this easy-to-use, intuitive IoT gateway achieves very low power consumption and can even be battery/solar powered.
SenseCeiver I/O - Wireless IoT Gateway with analog and digital inputs/outputs
4G|NB1|M1|3G|2G|GPS|
SenseCeiver I/O exchanges data with other devices or sensors via analog and digital inputs/outputs and enables real-time transmission to the cloud. Data is transmitted via mobile radio via LTE Cat NB1, LTE Cat M1, LTE 4G, 3G or 2G, depending on the variant.
SenseCeiver I/O can be configured quickly and easily and is freely programmable via the supplied Python SDK and Telit App Zone C.
Using energy-efficient components, this easy-to-use, intuitive IoT gateway achieves very low power consumption and can even be battery/solar powered.
Sensors
SenseCeiver has a line of direct sensor to internet sensors available for a number of applications.