What technology is NB-IOT

What technology is NB-IOT

The full Chinese name of Narrow Band Internet of Things: Narrow Band Internet of Things is what we call NB-IOT, which is mainly based on LTE technology (3GPP Release 13).

The difference and characteristics of NB-IOT and mobile communication (2/3/4/5G)

1. Wide coverage. Compared with traditional GSM, a base station can provide 10 times the area coverage, and an NB-IOT base station can cover a range of 10km, and a base station in a small county can cover. At the same time, NB-IoT has increased the gain of 20dB compared with LTE and GPRS base stations, and can cover underground garages, basements, underground pipes and other places where signals are difficult to reach. It is impossible to have signals to make calls underground, but NB-IOT can still communicate !

2. Massive connections, 200KHz frequency can provide 100,000 connections

The more connections provided, the fewer base stations will be built, and the fewer base stations will be built, then save money! One teacher teaches 200 students at the same time, and the other teacher can bring 20 students. In this way, on the premise of bringing 1000 students, the teacher with 200 students can only hire 5, and the latter teacher will hire 50. indivual.

3. Low power consumption, it can work for ten years with AA battery (No. 5 battery) without charging

No need to recharge for 10 years! Are you lying to me? My phone needs to be charged every day! NB-IoT introduces eDRX power saving technology and PSM power saving mode, which further reduces power consumption and extends battery life. In the PSM mode, the terminal is still registered on the network, but the signaling is unreachable, so that the terminal stays in deep sleep for a longer time to save power. The eDRX power-saving technology further extends the sleep period of the terminal in idle mode, reduces unnecessary startup of the receiving unit, and greatly improves the downlink reachability compared to PSM.

What is eDRX

DRX (Discontinuous Reception), that is, discontinuous reception. eDRX is extended discontinuous reception.

As shown in the figure, DRX receives signals discontinuously and rests most of the time. For example, continuous reception means that a security guard cannot leave the job 24 hours a day, and he must stare at the door carefully to see if there is any abnormality. Discontinuous reception means that the security guard only spends ten minutes to watch the door an hour, and has a tea break at other times.

PSM (Power Saving Mode), namely power saving mode. Many Internet of Things terminals have nothing to do most of the time. After reading the meter and sending a word, you can get a good night's sleep. The device enters the sleep state.

To sum up, the power saving of NB-IOT is like a security guard who has to take a break and drink tea for 50 minutes within an hour of work, so he only works 3 hours a day and sleeps at other times.

4. Mobility has been simplified. Unlike our mobile phones, it is often in cars, high-speed trains, and high-speed trains. The signal is not good. It is because the speed is too fast. The mobile phone is constantly switching base stations. Just like a relay race, the call is normal after the baton is connected. Lost, the call is intermittent or even dropped. Most scenarios of using NB-IOT for IoT terminals are static, such as smart meter reading, which can reduce the complexity of the protocol and reduce the cost of the module at the same time.

5. The half-duplex mode is what I'm talking about, you must listen, never interrupt! vice versa.

Insufficient NB-IOT

1 The deployment frequency is authorized and must be deployed by the operator! Want to build one yourself? At present, it still doesn't work. It seems that if you want to make a one-time investment, the road to no longer pay later will not work.

2 The cost of the module is still high now (compared to the mature GPRS module, wifi module), this should gradually decrease with the increase in usage.