NB-IoT is a new type of cellular technology developed by the 3GPP standardization organization. It belongs to the low-power wide-area (LPWA) IoT connection, that is mainly used to connect terminals with limited bandwidth resources, allowing terminals to collect and exchange data with less resources than GRPS, 3G, LTE and other technologies.
NB-IoT has developed rapidly in 2017-2018, and many operators around the world have realized commercial deployment one after another. The low cost, low power consumption and wide coverage of NB-IoT enable users to implement new scenarios and applications that traditional cellular networks cannot support.
Since 2017, EMQ X has started to cooperate with a top operator in the development of IoT platform project. In 2018, EMQ X released a new IoT Application Enabling Platform (AEP) supporting NB-IoT technology. The platform allows the NB-IoT terminals of customers in the industry to access directly through the operator NB-IoT network, and quickly construct the IoT application through the platform's open capability.
With the help of equipment access, message routing, data storage and equipment management and control services provided by AEP platform, the development process of applications can be greatly simplified. Most applications can be completed by dragging and dropping platform components and defining templates. Customers can also develop fully functional IoT applications through the platform's rich API interface and a small amount of coding work. Customer-developed applications can run directly on the platform, saving a lot of operating costs.
In this project, EMQ X IoT Message Middleware is the core component of the platform, which is used to access all kinds of IoT devices in the whole country (mainly NB-IoT, including 3G, 4G, PON, LAN, etc.) of operators. Through efficient protocol parsing and message routing capabilities, massive device messages are aggregated to the platform data layer, which also provide reliable reverse control channels for back-end device management and application modules.
EMQ X's innovative distributed clustering solution enables automatic addition of new nodes and automatic deletion of faulty nodes, which effectively guarantees the automatic expansion and long-term stable operation of the AEP platform's access capacity and improves the reliability of the carrier's customer service.
EMQ X has the capabilities of mass equipment access, 10 million high concurrency, IoT full protocol stack, and millisecond low latency that enable the carrier-grade IoT platform to be built in a few months, and effectively supports the landing and commercial operation of the operator's NB-IoT and even the whole IoT platform strategy.
[MQTT X](https://mqttx.app) is a cross-platform MQTT 5.0 desktop test client provided by the world's leading open source IoT middleware provider [EMQ](https://emqx.io) , which supports macOS, Linux, Windows. The user interface of **MQTT X** simplifies the operation logic of the page with the pattern of chatting software. Users can quickly create multiple simultaneous-online MQTT clients to test the connection/publish/subscribe functions of MQTT/TCP, MQTT/TLS and other MQTT protocol features.
The message retention function of [EMQ X MQTT Broker](https://emqx.io) is implemented by the `emqx_retainer` plugin, which is enabled by default. By modifying the configuration of the` emqx_retainer` plugin, you can adjust the EMQ X Broker's retention message Location, restrict the number of retained messages and maximum payload length, and adjust the expiration time of retained messages.
In April, EMQ X 4.3-beta.5 release summed up all the fixes has to be done before 4.3.0 release. This allowed us to gradually shift our focuses towards 5.0 development.