In the architecture of the Internet of Things, an intermediate device is needed between two different networks at the perception layer and the network layer, that is, the "Internet of Things Gateway". The IoT gateway can be used for both wide area network interconnection and local area network interconnection. In addition, the IoT gateway also needs to have device management functions. Operators c···

After GPRS DTU is powered on, first read the working parameters stored in the internal FLASH (including GPRS dialing parameters, serial port baud rate, data center IP address, etc., which have been configured in advance).

DTU is the full name of GPRS data transmission unit. At present, in China, there is actually a clearer agreement on GPRS DTU: GPRS DTU is a GPRS wireless device specially used to transmit serial data through the GPRS network. The following introduces the common problems of DTU application and the working engineering of GPRS DTU.

GPRS DTU is a wireless data terminal for the Internet of Things, which uses public operator networks to provide users with wireless long-distance data transmission. It uses high-performance industrial-grade 8/16/32-bit communication processors and industrial-grade wireless modules. The real-time operating system is a software support platform. It also provides RS232 and RS485 (or RS422) interfaces···

NB-IoT is Narrow Band-Internet of Things. It is a narrowband Internet of Things technology based on cellular networks. It focuses on low-power wide area networks and supports the cellular data connection of Internet of Things devices in the wide area network. It can be directly deployed with LTE networks, which can reduce Deployment costs and smooth upgrades are an IoT technology that can be widel···

LPWAN, Low Power Wide Area Network, Low Power Wide Area Network. There are two of its most important features in the name: low power consumption and wide coverage. Currently the more mainstream ones are: NB-IoT, LoRa, Sigfox, eMTC. The full name of NB-IoT is Narrow Band IoT, which is the narrowband Internet of Things (narrow bandwidth and slow speed).

LoRa's terminal nodes may be various devices, such as water and gas meters, smoke alarms, pet trackers, etc. These nodes are first connected to the LoRa gateway through LoRa wireless communication, and then connected to the network server through a 3G network or an Ethernet network. The gateway and the network server communicate through the TCP/IP protocol.

LoRa networking:The LoRaWAN network architecture is a typical star topology. In this network architecture, the LoRa gateway is a transparent transmission relay, connecting terminal devices and the back-end central server. The terminal device uses a single hop to communicate with one or more gateways. All nodes communicate with the gateway in both directions.

In summary, the application of NB-IoT is divided into four fields: public service field, personal field, industrial manufacturing field, new technology and new business field. Among them, smart metering of water, electricity and gas meters, public parking management, and environmental monitoring are listed as entry points in the field of public services.

NB-IoT is an emerging Internet of Things technology, which has attracted attention because of its low power consumption, stable connection, low cost, and excellent architecture optimization. Using the license frequency band, three deployment methods such as in-band, guardband or independent carrier can be adopted. , Coexist with the existing network.