--- title: "MQTT Broker for Fleet Telematics & Cold Chain | ConnectMQ" description: "A managed MQTT broker for vehicles, trackers and cold-chain sensors: lightweight messages over cellular, persistent sessions and per-vehicle permissions." url: "https://connectmq.com/fleet-logistics/" language: "en" --- Fleet Telematics # MQTT for Fleet Telematics Vehicles, trackers and cold-chain sensors report position and condition over mobile networks. MQTT’s small packets and persistent sessions suit links that come and go. [Try it free](https://app.connectmq.com/signup) [Quickstart](https://connectmq.com/developers/) No card required What you can build ## Build your fleet platform on ConnectMQ You build the applications, ConnectMQ moves the data. Vehicles publish once over MQTT; the dispatch dashboard, TMS integration, alerting and analytics you build each subscribe to the topics they need — add a new one without touching a single truck. Your vehicles **GPS tracker**fleet/{id}/gps **CAN / OBD-II telematics**fleet/{id}/engine **Reefer sensor**fleet/{id}/reefer/temperature **Driver app**fleet/{id}/pod **ConnectMQ** - TLS on 8883 - per-device ACL - persistent sessions - Last Will What you build on top **Dispatch dashboard** **TMS / WMS / ERP** **Alerts & customer ETAs** **Route optimisation** What you get ## Fleet Telematics on ConnectMQ - Lightweight messages for cellular connections - Persistent sessions so vehicles pick up queued commands after reconnecting - Keep-alive and Last Will to detect lost connectivity - Per-vehicle credentials and topic permissions example topic design ``` fleet/truck-084/gps fleet/truck-084/reefer/temperature fleet/truck-084/commands ``` **Cellular data** per vehicle / month **MQTT over TLS**78 MB one connection, tiny frames **HTTPS polling (keep-alive)**233 MB headers on every request **HTTPS, new connection per fix**1.4 GB TLS handshake every time Estimate per vehicle and month: one 60-byte GPS fix every 10 seconds over TLS, including TCP/IP and TLS overhead. For 500 vehicles that is about 39 GB with MQTT versus 117 GB with HTTPS polling. Data plans ## Up to 3× less cellular data than HTTP polling One long-lived MQTT connection and two-byte headers instead of a full HTTP request for every position. Across a fleet, that is the difference between a small IoT data plan and a large one. Real-life example ## A reefer door left open — fixed before the load warms up A common logistics setup with MQTT: the telematics unit in a refrigerated truck publishes over 4G, the dispatch system subscribes, and messages to the driver’s cab display travel back the same way. Reefer truck TRK-084 → ConnectMQ → Dispatch office. Publishes the reefer temperature and door state every 30 seconds over 4G. At a delivery stop the door stays open. Subscribed to fleet/+/reefer through ConnectMQ: its rule fires above 8 °C and sends a message to the driver’s cab display. Reads the message and closes the door; the unit reports the new state. Gets the all-clear when the trailer is back at 4.2 °C — the load is safe.ConnectMQMQTT broker · TLS 8883Rule: reefer above 8 °CTRK-0844.1 °C8.6 °C ▲4.2 °CDispatch officeTMS · subscribed4.1 °C6.3 °C8.6 °C6.0 °C4.2 °Cdoor openClose the reefer doorReefer truck TRK-084Telematics unit · 4Gfleet/trk-084/reefer {"temp":8.6,"door":"open"}fleet/trk-084/reefer {"temp":8.6,"door":"open"}fleet/trk-084/commands {"msg":"close door"}fleet/trk-084/commands {"msg":"close door"}fleet/trk-084/reefer {"door":"closed"}Dispatch · nowTRK-084 reefer back to 4.2 °CReefer truck TRK-084 → ConnectMQ → Dispatch office. Publishes the reefer temperature and door state every 30 seconds over 4G. At a delivery stop the door stays open. Subscribed to fleet/+/reefer through ConnectMQ: its rule fires above 8 °C and sends a message to the driver’s cab display. Reads the message and closes the door; the unit reports the new state. Gets the all-clear when the trailer is back at 4.2 °C — the load is safe.ConnectMQMQTT broker · TLS 8883Rule: reefer above 8 °CTRK-0844.1 °C8.6 °C ▲4.2 °CDispatch officeTMS · subscribed4.1 °C6.3 °C8.6 °C6.0 °C4.2 °Cdoor openClose the reefer doorReefer truck TRK-084Telematics unit · 4Gfleet/trk-084/reefer {"temp":8.6,"door":"open"}fleet/trk-084/reefer {"temp":8.6,"door":"open"}fleet/trk-084/commands {"msg":"close door"}fleet/trk-084/commands {"msg":"close door"}fleet/trk-084/reefer {"door":"closed"}Dispatch · nowTRK-084 reefer back to 4.2 °C 1. 10:42 **Telematics unit in TRK-084** Publishes the reefer temperature and door state every 30 seconds over 4G. At a delivery stop the door stays open. `fleet/trk-084/reefer → {"temp":8.6,"door":"open"}` 2. 10:42 **Dispatch system** Subscribed to fleet/+/reefer through ConnectMQ: its rule fires above 8 °C and sends a message to the driver’s cab display. `fleet/trk-084/commands → {"display":"Close the reefer door"}` 3. 10:43 **Driver in the cab** Reads the message and closes the door; the unit reports the new state. `fleet/trk-084/reefer → {"temp":7.1,"door":"closed"}` 4. 10:55 **Dispatcher** Gets the all-clear when the trailer is back at 4.2 °C — the load is safe. **In a tunnel or a dead zone,** the command waits in the truck’s persistent session on ConnectMQ and is delivered with QoS 1 the moment the truck reconnects (`QoS 1 · persistent session`). [ESP32 code sample](https://connectmq.com/code-samples/esp32/) [Node.js code sample](https://connectmq.com/code-samples/nodejs/) Platform ## Features that help with Fleet Telematics [ ### Dashboard & monitoring Live topic cards, signals and ISA-95 workspace Learn more](https://connectmq.com/monitoring/)[ ### Rules & alerts Threshold rules, alert log and notifications Learn more](https://connectmq.com/rules-alerts/)[ ### Connectivity MQTT 3.1.1 and 5 over TCP, TLS, WS and WSS Learn more](https://connectmq.com/connectivity/) Solutions ## Other ways teams use ConnectMQ [ ### Industrial IoT & Smart Manufacturing Machines, PLC gateways, OEE and quality data ](https://connectmq.com/industrial-iot/)[ ### Smart Home Hubs, sensors and Home Assistant setups ](https://connectmq.com/smart-home/)[ ### Smart Energy Meters, EV chargers, solar and batteries ](https://connectmq.com/energy-utilities/)[ ### Connected Products & Smart Hardware Smart devices you ship to your own customers ](https://connectmq.com/connected-products/)[ ### Connected Robots & Physical AI Robot fleets talking to fleet managers and AI pipelines ](https://connectmq.com/robotics/)[ ### Data Center Monitoring Power, cooling and rack environment ](https://connectmq.com/data-centers/)[ ### Smart City Streetlights, parking, air and waste sensors ](https://connectmq.com/smart-city/)[ ### Smart Agriculture Soil probes, weather stations and irrigation ](https://connectmq.com/smart-agriculture/)[ ### Prototyping & Education From first ESP32 to classroom labs ](https://connectmq.com/prototyping-education/) Industries & use cases ## Where teams use Fleet Telematics ### Industries - [Automotive](https://connectmq.com/industries/automotive/) - [Pharma & Life Sciences](https://connectmq.com/industries/pharma-life-sciences/) - [Food & Beverage](https://connectmq.com/industries/food-beverage/) - [Transportation & Logistics](https://connectmq.com/industries/transportation-logistics/) - [Retail & E-commerce](https://connectmq.com/industries/retail-ecommerce/) ### Use cases - [Connected Vehicles](https://connectmq.com/use-cases/connected-vehicles/) - [Fleet Management](https://connectmq.com/use-cases/fleet-management/) - [Cold Chain Monitoring](https://connectmq.com/use-cases/cold-chain-monitoring/) Pilot ## Put your first trucks on MQTT this week Start on the Free plan with no card. Basic covers up to 100 concurrent connections — enough to pilot a route with real vehicles. Move to Scale when the whole fleet goes live. [Start for free](https://app.connectmq.com/signup) [See pricing](https://connectmq.com/pricing/) ## Articles [All articles](https://connectmq.com/blog/) MQTT Fundamentals ### [MQTT QoS Levels Explained: QoS 0, 1 and 2 with Packet Flows and Examples](https://connectmq.com/blog/mqtt-qos-levels-explained/) A practical guide to MQTT QoS: how QoS 0, 1 and 2 work on the wire, why the delivered QoS can be lower than you asked for, how sessions queue messages and which level to choose for each use case. August 20, 20269 min read MQTT Fundamentals ### [MQTT 5 Features That Matter in Practice: Reason Codes, Shared Subscriptions, Expiry and More](https://connectmq.com/blog/mqtt-5-features/) MQTT 5 is more than a version bump. Learn the features that change how you build IoT systems, from reason codes and expiry to shared subscriptions and request/response, with hands-on examples. September 22, 20269 min read Managed MQTT Cloud ### [How to Choose an IoT MQTT Broker: 12 Criteria and the Questions to Ask Your Vendor](https://connectmq.com/blog/how-to-choose-an-iot-mqtt-broker/) A practical 12-point checklist for choosing an IoT MQTT broker, a table of questions to ask every vendor, and a five-minute hands-on test you can run against broker.connectmq.com. September 21, 20269 min read