What is the difference between narrowband and broadband What are the advantages of narrowband

In the Internet of Things industry, Narrowband Internet of Things (NB-IoT) is an emerging technology that can be widely used around the world. It has unique advantages, such as wide coverage, multiple connections, low speed, low cost, and low power consumption. Excellent architecture features. NB-IOT uses the license frequency band, and can be deployed in three ways: in-band, guard band, or independent carrier, and coexists with the existing network.

What is the difference between narrowband and broadband?

In the communications industry, bandwidth may have two meanings. One is the frequency bandwidth, referred to as bandwidth, and the unit is Hz; the other is the maximum transmission rate of the network, and the unit is bps. Broadband is an artificially defined term without strict standards. 

In wireless communication, the working frequency of radio waves is involved. For example, the main working frequency of 4G of China Unicom and China Telecom that we often encounter is 1800Mhz. 

Wireless spectrum is a precious and completely non-renewable resource, and signals of the same frequency will interfere with each other, so the frequency must be divided into segments of different ranges, and this range is the difference between the highest frequency and the lowest frequency The value, that is, the frequency bandwidth, is also often referred to simply as bandwidth.

Different mobile communication standards support different bandwidths. For example, LTE can support different bandwidths such as 1.4Mhz, 3Mhz, 5Mhz, 10Mhz, 15Mhz, and 20Mhz. 

"Narrow" and "wide" are relative concepts, and there is no strict numerical limit.Relative to what? It refers to channel characteristics relative to signal characteristics.

First, the signal to be transmitted is called the source, and the source has certain spectral characteristics. The source signal usually needs a carrier signal to modulate it before it can be sent to a distant place. The bandwidth of the source signal is much smaller than the center frequency of the carrier If the signal is narrowband, on the contrary, if the two are comparable in size, it is called a broadband signal.

Second, in actual communication, the frequency band resource allocated to you + the real propagation environment, we call it a channel. Channels also have certain spectral characteristics. Generally, the wider the allocated frequency band resources and the more stable the propagation environment, the higher the data rate that the channel can carry.

Third, from the spectrum of the waveform, the signal bandwidth is Δf, and the carrier frequency is fc. When Δf<<fc, the system is called a narrowband system. What is a system? The composition of the "system" is the source + channel, where Δf can be considered as the source feature, and fc can be considered as the channel feature. Comparing the first article of this discussion, it can be seen that "narrowband channel" and "narrowband signal" are actually within the same definition category, that is, "narrowband system", and the two complement each other.

Fourth, what problems will arise when broadband signals are transmitted on narrowband channels? The answer: frequency selective fading. This problem is more difficult to describe. A simple analogy is like a very wide car driving on a road that is narrower than it. Or a biscuit production line, on the assembly line, a large number of biscuits enter a narrow receiving channel, and the biscuits on both sides will inevitably fall to the ground.

NB-IoT Technology Application Scenarios

Narrowband Internet of Things (NB-IoT) technology is applied to agriculture, industry, government and life. Widely used in real-time monitoring and early warning of environmental data such as oil fields, oil wells, gas fields, steam pipelines, heating pipelines, water pump rooms, refrigeration, storage, agricultural greenhouses, and breeding. It is used in wireless monitoring and early warning of computer room, machine station power, environmental monitoring system, low-voltage power distribution monitoring system, electric energy data monitoring system, factory machinery equipment, production line operation status monitoring system, production information collection system, etc.