Concept of Narrowband Transmission
In the communication industry, bandwidth typically refers to two concepts: one is frequency bandwidth, and the other is maximum transmission rate (bps). Narrowband transmission refers to a technology that limits the signal transmission to a relatively narrow frequency range during data transfer. Usually, the bandwidth of a narrowband signal is much smaller than the total bandwidth of the transmission channel, typically ranging from a few kHz to tens of kHz, or even narrower.
The working principle can be briefly summarized in four points as follows:
Signal Modulation: The baseband signal is modulated onto a high-frequency carrier by varying the amplitude, frequency, or phase of the carrier to carry the baseband signal information. Common modulation techniques include Amplitude Modulation (AM), Frequency Modulation (FM), and Phase Shift Keying (PSK).
Channel Coding: In the transmitting end, the raw data is processed by adding redundant codewords to improve the signal's resistance to interference and error correction capabilities. Examples of such coding techniques include parity check codes, convolution codes, and Turbo codes.
Synchronization Technology: The receiving end needs to synchronize with the transmitting end in terms of carrier synchronization, bit synchronization, and frame synchronization to ensure accurate reception and restoration of the signal.
Multiple Access Technology: This includes Frequency Division Multiple Access (FDMA), Time Division Multiple Access (TDMA), and Code Division Multiple Access (CDMA), which allow multiple users to share the same narrowband channel, enabling simultaneous communication between multiple users.
Advantages of Narrowband Transmission
Narrowband transmission is an emerging technology with unique advantages and wide applicability globally. It is characterized by broad coverage, multiple connections, strong anti-interference ability, stable data transmission, low rate, low cost, low power consumption, and architectural advantages.
For instance, the E49 series narrowband module from Chengdu Yibaiter Electronics Technology Co., Ltd., uses narrowband transmission and features concentrated power spectral density, strong stability, anti-interference capabilities, and long transmission distance. It also incorporates the Forward Error Correction (FEC) algorithm, which significantly enhances error correction and coding efficiency. This feature ensures that under burst interference, the disturbed data packets can be actively corrected, greatly improving communication reliability and transmission range. Compared to spread-spectrum transmission, narrowband transmission offers the advantages of lower standby current and higher air transmission rate.
Under the same power conditions, the power density of narrowband transmission is higher than that of standard communication, and its transmission distance is twice that of regular modules.
Applications of Narrowband Transmission
Due to its low power consumption and strong penetration, narrowband transmission has wide applications in various fields. Some of the key application scenarios include:
Internet of Things (IoT): In industrial production, narrowband transmission is used to connect various industrial sensors, monitoring equipment, and actuators, enabling real-time monitoring and automated control of the production process. For example, in industries like petrochemical and electric power, narrowband transmission modules can transmit data from sensors located in different areas to a central control center, allowing workers to monitor equipment status and environmental parameters, ensuring safe and efficient production.
Healthcare: Enterprises and offices handle large amounts of data and network communication, which requires high network stability and speed. WiFi modules can effectively improve network quality, ensuring smooth business operations.
Agriculture: In the production and circulation of agricultural products, narrowband transmission can be used in traceability systems to monitor the entire process of agricultural products, from planting and processing to sales. Consumers can scan a product’s QR code to obtain information such as the origin, fertilizer and pesticide usage, harvest time, and transportation process, ensuring food safety.
Transportation: Narrowband transmission can be used in traffic flow monitoring, intelligent parking management, and road condition monitoring. For instance, traffic flow sensors installed on roads can transmit data such as traffic volume and vehicle speed to a central traffic management center via narrowband transmission, enabling intelligent control of traffic lights and real-time traffic congestion management.