Hi All,

I am using the Quectel BG95-M3 and have it connected to my MQTT server (Azure IoT Hub).
Sometimes we notice there is latency when sending a message to the device. Is this normal for GSM modules? It seems to be significantly slower at times compared to a Wi-Fi module, even though we are only sending small amounts of data.

Could you please share your experiences?

 

Your QoS on the GSM network will be very low using an IoT focused SIM. You will have a very low priority and loading of your local cell will result in variable latency.

It is incommensurable with Wi-Fi. Despite both being wireless networks, that accomplish the same application layer function for you, it is very much an apples to oranges comparison when considering latency.

Concerning the "small amounts of data", remember that you are dealing with a packetized system and even a single packet has to be received and forwarded by the cell tower. It doesn't care how few bytes you put in that packet, it just sees a packet to handle and does—or doesn't—based on system loading and your priority in getting service.