Telemetry is the automatic collection and transmission of measurements from remote equipment to a central system for monitoring, analysis, or control. It is the underlying purpose of most industrial IoT: getting data from where it is generated to where it can be acted upon.

In short: Telemetry covers a wide range of applications, including utility meter readings, environmental sensors (temperature, humidity, air quality), industrial process variables (flow, pressure, level, vibration), fleet and vehicle data (location, speed, fuel, diagnostics), and asset monitoring (occupancy, status, condition). Telemetry traffic patterns are typically lightweight per message (a few bytes to a few kilobytes) but high in volume across an estate, with strict requirements for reliability and predictable delivery.

For cellular telemetry, the choice of bearer matters. NB-IoT and LTE-M are designed for the low-data, long-battery-life telemetry profile: smart meters, environmental sensors, asset trackers. 4G LTE (often Cat 1 or Cat 4) suits applications that send larger payloads or require lower latency. 5G RedCap is positioning as the next-generation choice for telemetry that needs more headroom than NB-IoT and LTE-M can provide, but does not need the cost or complexity of full 5G.

Protocols for telemetry have largely consolidated around MQTT and HTTP(S) for cloud integration, with CoAP used in some constrained-device contexts. Industrial cellular routers typically support both, often with onboard logic for buffering, batching, and protocol translation, so telemetry from a Modbus or serial device can be repackaged as MQTT messages to a cloud broker.