nb-What are the characteristics of iot?

NB-IoT has the following four characteristics:

1. Wide coverage. Compared with existing GSM, broadband LTE and other network coverage, the coverage is enhanced by 20dB, the signal transmission coverage is larger (GSM base station can currently cover 35km under ideal conditions), and it can cover places that cannot be covered by deep underground GSM networks. Its principle mainly relies on: 1. Reduce bandwidth and increase power spectral density; 2. Repeat transmission to obtain time diversity gain.

2. Big connection. Compared with existing wireless technology, the number of accesses under the same base station is increased by 50-100 times, and each cell can reach 50K connections. This is truly a massive number of connections necessary to realize the interconnection of all things. The principle is: 1. Based on the characteristics of delay insensitivity, the traffic model is adopted to save the context of more access devices and switch between dormant and active states; 2. The uplink scheduling granularity of narrowband Internet of Things is small and resources are Higher utilization rate; 3. Reduce air interface signaling interactions and increase spectrum density.

3. Low power consumption. The terminal is in a dormant state for 99% of the time and integrates a variety of power-saving technologies, with a standby time of up to 10 years. 1. PSM low power consumption mode, that is, adding a PSM state in the idle state, which is equivalent to shutting down, and is controlled by a timer to wake up, which consumes less energy; 2. eDRX extended discontinuous reception power saving mode uses a longer During the paging cycle, eDRX is 1/16 of the power consumption of DRX. 4. Low cost. The hardware can be tailored and the software can be simplified as needed, ensuring the low cost of NB-IoT. The cost of a single NB-IoT communication module is less than US$5.