Comparison and application of 433MHz and 24GHz wireless transmission methods and GPRS

The difference and application of 433MHz 2 4GHz and GPRS wireless transmission methods

Three wireless transmission communication methods, including 433MHz, 2.4GHz and GPRS, are used in the Shenzhen-Xinli wireless data collection and transmission system solution. Each has its own advantages and disadvantages, as well as different application scenarios. The common ones are mainly used in the following three situations. ：

1. Sensor signal: signal sensing, processing, wireless transmission; Xinli/XL61 wireless temperature sensor, (PT100, PT1000, Cu50, and S, J, K type thermocouples), wireless pressure sensor, wireless gas sensor , wireless temperature and humidity sensor, wireless displacement sensor, lighting, vibration, etc.

2. Standard signal collection, processing, wireless transmission: 4~20mA, 0~20mA, 0~5V, 1~5V; switch input; analog output, switch output;

3. Data reading and wireless transmission of smart devices and smart devices: Read the data of devices and devices with communication interfaces and upload them wirelessly.

1. 433MHz wireless transmission communication method

·Modulation method: DSSS, GFSK;

·Frequency: 433MHz (433~437.5MHz) ISM band;

·Transmit power: 20dBm, 100mW;

·Receive sensitivity: -117dBm;

·Ideal transmission distance: 2Km;

·Communication rate: 1200-115200bps;

·Number of channels: 30;

·Star network structure;

·Suitable for data transmission between different floors, workshops, and factories.

2. 2.4GHz wireless transmission communication method

1. Modulation method: DSSS, 0-QPSH;

2. Frequency: 2.400~2.4835GHz ISM frequency band;

3. Transmit power: ≤20dBm(100mW);

4. Receiving sensitivity: -97dBm;

5. Transmission distance: 1.2Km;

6, self-organizing network, self-routing;

7. Suitable for data transmission in the same workshop, factory building, adjacent floors, etc.

3. GPRS wireless transmission communication method

1. Wireless parameters: GSM900/1800 dual-band (optional GSM850/900/1800/1900 quad-band);

2. Uplink bandwidth: maximum 42.8 kbps; downlink bandwidth: maximum 85.6 kbps;

3, 16 channels, bandwidth 80MHz;

4. Support China Mobile and China Unicom 2.5G standard;

5. The NB-IOT solution is under testing;

6. Transmission distance: not limited by distance;

7. Suitable for cross-regional and inter-regional long-distance data transmission.

What are the remote wireless data transmission methods? By which devices

There are 6 methods of wireless data transmission, namely:

1.Microwave transmission

is one of the solutions for monitoring and transmitting in places that are difficult to wire for several kilometers or even dozens of kilometers. Using frequency modulation or amplitude modulation, the image is loaded onto a high-frequency carrier and converted into high-frequency electromagnetic waves for air transmission. Its advantages are: low overall cost, more stable performance, eliminating wiring and cable maintenance costs; it can dynamically transmit broadcast-level images in real time, with good image transmission clarity and completely real-time; flexible networking, good scalability, and plug-in Ready to use; low maintenance. Its disadvantages are: due to the use of microwave transmission, the frequency band is above 1GHz. Commonly used ones are L-band (1.0~2.0GHz), S-band (2.0~3.0GHz), and Ku-band (10~12GHz). The transmission environment is an open space. If used in big cities, radio waves are relatively complex and relatively susceptible to external electromagnetic interference; microwave signals are transmitted in straight lines and cannot be blocked by mountains or buildings; if there are obstacles, relays need to be added to solve them. The Ku band is affected by the weather. It is more serious, especially in rainy and snowy weather, which will cause serious rain attenuation. However, there are now digital microwave video transmission products, with much improved anti-interference capabilities and scalability.

2. Twisted pair transmission

is also a type of video baseband transmission, which converts the 75Ω unbalanced mode into a balanced mode for transmission. It is a good solution for the transmission of surveillance images within 1Km, the electromagnetic environment is relatively complex, and the situation is better. The surveillance image signal is processed and transmitted in a balanced and symmetrical manner. Its advantages are: simple wiring, low cost, and strong resistance to common mode interference. Its disadvantages are: it can only transmit surveillance images within 1Km, and one twisted pair can only transmit one image, so it is not suitable for use in large and medium-sized surveillance; the twisted pair is fragile and has poor anti-aging capabilities, so it is not suitable for field transmission; double The high-frequency components transmitted by twisted wires are attenuated greatly, and the image color will be greatly lost.

3. Video baseband transmission

is the most traditional TV monitoring transmission method. It does not process the 0~6MHz video baseband signal and directly transmits analog signals through coaxial cables (unbalanced). Its advantages are: small loss of image signal in short-distance transmission, low cost, and stable system. Disadvantages: The transmission distance is short, and the high-frequency component is attenuated more than 300 meters, so the image quality cannot be guaranteed; one cable is required for one video signal, and another cable is required for transmitting control signals; its structure is a star structure, which requires a large amount of wiring and maintenance Difficult, poor scalability, suitable for small systems.

4. Optical fiber transmission

Common ones include analog optical transceivers and digital optical transceivers, which are the best solution for TV surveillance transmission for tens or even hundreds of kilometers. They convert video and control signals into laser signals for transmission in optical fibers. Its advantages are: long transmission distance, small attenuation, good anti-interference performance, and suitable for long-distance transmission. Its disadvantages are: it is not economical enough for monitoring signal transmission within a few kilometers; optical splicing and maintenance require professional technicians and equipment operations, and the maintenance technology must be high, and it is not easy to upgrade and expand capacity.

Wireless transmission technology network transmission

is a monitoring transmission method that solves the problem of long distance and extremely dispersed points in urban areas. It uses MPEG2/4 and H.264 audio and video compression formats to transmit monitoring signals. The advantage is that the network video server is used as the monitoring signal uploading device. As long as there is an Internet network, remote monitoring software can be installed to monitor and control. Its disadvantages are: limited by network bandwidth and speed, current ADSL can only transmit small-screen, low-quality images; it can only transmit a few to a dozen frames of images per second, and the animation effect is very obvious and delayed, making it impossible to to real-time monitoring.

5. Broadband common cable transmission

The video uses amplitude modulation modulation, audio audio piggybacking, FSK data signal modulation and other technologies to integrate dozens of monitoring images, audio, control and alarm signals into "one" coaxial cable for bidirectional transmission. Its advantages are: it makes full use of the resource space of the coaxial cable, and thirty audio, video and control signals are transmitted bidirectionally in the same cable to achieve "one line communication"; it is simple to construct and maintain, and saves a lot of material costs and construction costs; frequency division Multiplexing technology solves the monitoring and transmission problems of scattered long-distance transmission points and difficult wiring; the radio frequency transmission method only attenuates the carrier signal, and the image signal attenuation is relatively small. The brightness and chroma transmission are nested simultaneously to ensure that the image quality reaches about level 4; using 75Ω The coaxial unbalanced transmission method makes it have strong anti-interference ability, and the image quality can still be guaranteed in complex electromagnetic environment. Its disadvantages are: weak signal transmission is used, system debugging technology must be high, and professional instruments must be used. If there is a problem with one device in the trunk line, it may cause the entire system to have no image. In addition, the wide-band modulation end needs to be powered by an AC220V AC power supply (but currently most All monitoring points have the condition of AC220V AC power supply).

6. Wireless SmartAir transmission

SmartAir technology is currently the only single-antenna mode gigabit wireless high-speed transmission technology in the communications industry. It uses multi-band OFDM air interface technology, TDMA's low-latency scheduling technology, and advanced wireless communication technologies such as low-density parity check code LDPC, adaptive modulation coding AMC and hybrid automatic repeat HARQ to achieve a transmission rate of 1Gbps.

Required: mobile phone; computer; wireless network card; wireless LAN WLAN

How many types of wireless data transmission methods are there? What are their advantages

1. 2.4G wireless data transmission. The 2.4G module is designed with low power consumption and the ideal transmission distance is 1.5 kilometers. It is usually used for data collection with relatively short transmission distance.

2. 433M wireless data transmission. 433M module, strong signal, long transmission distance, ideal transmission distance is about 3 kilometers. It also has strong penetration and diffraction capabilities, and small attenuation during the transmission process. Shenzhen Xinli 433M module can realize ultra-low power consumption operation of collection and transmission communication equipment, ensuring uninterrupted real-time data transmission and battery life of up to 5 years.

3. GPRS wireless data transmission. GPRS module has unlimited transmission distance, large transmission data, safe and stable, and is usually used for remote data collection and transmission.

4. NB-IOT low-power wide area network wireless data transmission. The characteristics of NB-IoT are mainly reflected in four aspects: First, wide coverage will provide improved indoor coverage. In the same frequency band, NB-IoT has a gain of 20dB compared to the existing network, which is equivalent to a 100-fold increase in coverage. Second, it has the ability to support massive connections. One NB-IoT sector can support 100,000 connections, supporting low latency sensitivity, ultra-low equipment cost, low equipment power consumption and optimized network architecture; Third, lower power consumption, the standby time of NB-IoT terminal modules can be up to 10 years; fourth, lower module cost, enterprises expect a single connected module to be no more than 5 US dollars.

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