Smart street light systems with NB-IoT technology have become more and more popular. It saves energy and makes the maintenance and management of street lights more convenient. And NB-IoT is the way of communicating that ensures the functions of the system. Read on to find out the exact benefits of NB-IoT street lighting!
Low costs
Unlike LoRa, the network, radio frequency, and antenna can be reused in an NB-IoT system. There are three low-cost deployment methods for NB-IoT.
The first is a stand-alone deployment. Independent deployment means that NB-IoT can operate independently of the existing LTE network. GSM channel bandwidth is 200 kHz, which is more than enough to accommodate the 180 kHz bandwidth of NB-IoT. So this method is appropriate for the GSM frequency band.
The second type is referred to as guard band deployment. Because NB-IoT is narrow enough to be deployed on the existing 4G frequency band’s protection bandwidth, some of the resources that were not used can be reused.
The third type of deployment is in-band deployment, which can occur directly within the 4G frequency band. Each 4G small resource block has a bandwidth of 180 kHz. Because NB-IoT is based on 4G technology, its bandwidth is also 180 kHz.
Regardless of how it is deployed, NB-IoT will not rely on any system’s signal resources.
Furthermore, for NB-IoT, a single antenna and FDD half-duplex are sufficient to meet the communication needs. This design significantly reduces costs.
Low power consumption
In order to save power, NB-IoT has developed two distinct modes: eDRX and PSM.
eDRX mode is a more advanced version of DRX mode. An example of the DRX mode application is mobile phone paging. Every now and then, the phone will page, after which it will enter the IDLE state and turn off the receiver. However, because communication equipment in street lights cannot be charged frequently and the system should save as much energy as possible, the eDRX mode was developed. A PTW paging time window is designed based on DRX. The IoT device will page three times during each window. Following that, it will enter a long dormancy that can last up to 2.92 hours.
The PSM mode is designed to extend the sleep cycle in order to reduce power consumption even further. However, if the application layer issues an instruction to the terminal in PSM mode, it can only wait for the terminal to wake up before sending it out. As a result, this mode is incompatible with smart street lighting systems. Actually, the eDRX mode has already made NB-IoT quite energy efficient.
Wide coverage
NB-IoT has excellent indoor coverage, which is 20 dB higher than LTE, equating to a 100-fold increase in coverage area capabilities. It can get through two more walls than GPRS.
From the downstream perspective, it primarily improves transmission reliability by repeatedly sending to obtain greater gains. In terms of the uplink, on the one hand, the gain is also increased through repeated transmission. For transmission, a single sub carrier, namely a 15KHz sub carrier, is used. Compared with NB-IoT, the 4G network must transmit at least 180 kHz every time. As a result, the gain of data transmission in narrow band is greater under the same transmission power.
Extra–large connection
NB-IoT can provide 50–100 times more access points than existing technologies using the same base station. There can be as many as 100,000 connections in a single sector. At the same time, the system can maintain low latency sensitivity, ultra-low equipment costs, and an optimized network architecture. Because the communication quality requirements for IoT devices are lower than those for mobile phones, more terminals can be connected within the same base station range. A large number of IoT devices can be accommodated within the scope of a base station because many of them are dormant.
Multiple functions
- To achieve energy savings while meeting illumination requirements, there are various modes of the NB-IoT street lighting system. For example, full brightness mode of street lights in time periods, automatic adjustment mode (based on ambient light intensity or voltage and current threshold), and terminal joint control mode
- The location of each street lamp can be intuitively located on the mobile app, PC application, and Web platform interface using the GPS geographical information management system. The system makes it easier for maintenance personnel to determine the address of faulty street lamps and repair them in time.
- Information such as working status, voltage, current, power, and other information about street light nodes can be collected using high-precision data collection and communication technology. Managers can also specify environmental factors such as ambient light intensity and humidity.
- The system can realize street lamp node urban portrait data analysis.
Conclusions
We choose the NB-IoT street lighting system because of its low cost, large amount of connection, low consumption of energy, wide coverage, and multiple functions. NB-IoT has played an important role in many fields and is sure to be one of the key technologies for smart street light systems.
