What determines the communication distance of the wireless module? Selection is very important for antenna 2020-2-18whwireless The communication distance of wireless module is an important index. How to maximize the effective communication distance has always been a puzzle for customers. In this paper, according to the debugging experience, the selection and use of the antenna are explained, hoping to help engineers quickly debug the communication distance. The primary parameter affecting the communication distance of the wireless module is the transmission power. The transmission power of the wireless module and the corresponding ideal transmission distance can be found in the manual. On the premise that the transmission power meets the requirements, the selection of the antenna and the directionality of the antenna are considered. The first is the selection of antenna: The main specifications of the antenna include the following: frequency range, SWR or VSWR, antenna gain, polarization mode and impedance. The frequency range should be selected as required; the VSWR should be less than 1.5; the antenna gain also affects the transmission distance; the polarization mode can be divided into linear polarization and circular polarization; the impedance needs to match the output impedance of the wireless module, generally 50 ohms. Pay special attention to VSWR parameters here. It is better to test SWR with network analyzer after purchasing antenna. The comparison table of SWR, return loss and transmission power is shown in Table 1. It can be seen from the above table that when VSWR = 1.5, the theoretical transmission power is 96%. When VSWR = 2, the transmission power is only 88.9%. Some antenna VSWR indexes are less than 2. When selecting an antenna, the best VSWR is less than 1.5, which can get higher transmission power. Secondly, antenna directionality: Antenna has directionality, which means that antenna has different radiation or receiving ability in different directions of space. The antenna directionality is usually measured by using a pattern. Figure 1 shows a pattern of an antenna with a frequency range from 2400mhz to 2500mhz. When the antenna is placed vertically, the direction with the deepest red color is the direction with the strongest radiation or receiving ability of the antenna. Therefore, when installing the antenna, install the antenna in the direction with the red color as much as possible, so as to ensure good signal quality. In addition, the metal plate has a shielding effect on the signal, so there should be no metal plane in the direction of transmitting and receiving. There are also some antenna directions shown in the manual, which are represented by two-dimensional drawings, including H-plane and E-plane, as shown in Figure 2. When testing the communication between wireless modules, the directionality of the antenna must be considered. When the communication space is not blocked and the direction of the antenna corresponds ...

Don't be confused anymore! What is the difference between5GWiFi and5G? Read in 10 minutes Recently, the Ministry of Industry and Information Technology has officially issued5Gcommercial licenses to China Telecom, China Mobile, China Unicom, and China Radio and Television, which also indicates thatChinahas officially entered the5Gera. https://www.whwireless.com/omni-5g-4g-3g-2g-8dbi-dual-polarization-m2m-iot-antenna_p494.html But for many users, the term exposure to5Gstarts with5GWiFi. Now, with the commercialization of5G, many users are confused. What is the difference between5GWiFi and5G?   The confusion of WiFi and5G Although5GWiFi and5Gboth have the word "5G", they have completely different meanings. Both standards and application scenarios represent two different technologies.   •5GWiFi is precisely 5GHz WiFi, which refers to the 5GHz working frequency band of the IEEE 802.11 series of protocols. •5Gis short for 5th Generation, which is the 5th generation mobile communication technology and standard.   https://www.whwireless.com/diy-antenna-and-enclosure-wlan-wifi-system-antenna_p229.html As we all know, WiFi belongs to the local area network wireless technology and is mainly used in indoor scenarios. With the application of WiFi6 technology, compared with 5G mobile communications, WiFi is widely used in corporate LANs, homes, and other advantages due to its high throughput, lower equipment and terminal costs, extremely low operation and maintenance costs, and regional secrecy. Internal device interconnection, private network internal connection, etc., to avoid network congestion caused by too many devices or terminals accessing the operator's core network.   5Gmobile communication belongs to wide area network technology, which has the advantages of wide coverage and support for high-speed mobile environments. It is mainly used in many scenarios such as outdoor connection, mobile medical, Internet of Vehicles, environmental monitoring, and metropolitan area networks.   It can be seen that although there is a certain degree of overlap between WiFi and5Gin application scenarios, they are more complementary and jointly achieve a true seamless network connection.   However, as two of the most widely used wireless connection technologies,4GLTE as the representative of mobile communication and WiFi disputes endlessly. Nowadays, with the imminent large-scale commercialization of5Gmobile communication, the transmission rate is expected to reach dozens of times more than 4G LTE. The call for5Gto replace WiFi, what's the truth?   The convergence of WiFi and5G Cees Links, known as "the father of WiFi," stated in 2017: "From 1999 to 2000, some people put forward the idea that2Gwill replace WiFi; from 2008 to 2009, there was also speculation that4Gwill replace WiFi. However, the application scenario modes of5Gand WiFi are different. WiFi is mainly used in indoor environments, and5Gis a WAN technology. It has more outdoor...

Advantages of Nb IOT wireless communication technology Wellhope Communication Equipment Factory The narrow band Internet of things (NB IOT) is built on the cellular network, which has the advantages of low power consumption, wide coverage, low cost and strong link, making its traditional measurement transmission easy to deploy and manage. The advantages are detailed as follows. 1. Strong link In the case of the same base station, Nb IOT can provide 50-100 times more access than the existing wireless technology. A sector can support 100000 connections, low latency sensitivity, low device power consumption and optimized network architecture. Reference link: https://www.whwireless.com/small-dimension-high-performance-magnet-antenna_p485.html 2. Wide coverage Compared with LTE, Nb IOT has strong indoor and basement coverage, with a gain of 20dB, which is equivalent to 100 times of coverage area capacity. It can not only meet the needs of wide coverage in rural areas, but also can be applied to plant areas, underground garages, well covers and other applications requiring deep coverage. Take the well cover monitoring as an example. In the past, GPRS needs to extend an antenna, which is very easy to be damaged when vehicles travel. As long as NB IOT is properly deployed, it can solve this problem. Intelligent well cover monitoring has solutions, and provides equipment and solutions for many cities. 3. Low power consumption Low power consumption is an important indicator requirement for Internet of things applications, especially for some devices and occasions that can't replace batteries frequently, such as various kinds of sensor monitoring devices installed in remote areas of mountains and wilderness, and power voltage monitoring devices, which can't be charged like smart phones one day, so the battery life for several years is the essential demand. NB IOT focuses on small data volume and small rate applications, so the power consumption of Nb IOT equipment can be very small, and the endurance working time of the equipment can be greatly increased from the past few months to several years. 4. Low cost Compared with Lora andZigBee,NbIOT does not need to be rebuilt, and RF and antenna are basically multiplexing. Taking China Mobile as an example, 900MHz has a relatively wide frequency band. Only a part of2Gfrequency band needs to be cleared, and LTE and Nb IOT can be deployed directly at the same time. Low speed, low power consumption and low bandwidth also bring low cost advantages to NB IOT chips and modules. WHWIRELESS 2020-1-8

Massivemimo, that is, large-scale MIMO (multiple input multiple output) technology, aims to greatly improve network capacity and signal quality through more antennas. In principle, it can be compared with Expressway to expand the number of roads to improve traffic flow. The 5g base station with massivemimo can not only improve the network capacity by multiplexing more wireless signal streams, but also greatly improve the network coverage capacity by beamforming. By adjusting the spatial distribution of antenna gain, beamforming technology makes the signal energy more concentrated to the target terminal when transmitting, so as to make up for the loss of spatial transmission after signal transmission and greatly improve the network coverage. Compared with 4G base station, AAU supporting large-scale array antenna technology is the main reason for the significant increase of5gbase station cost. Screenshot9.21.43 amFebruary 28, 2019 Antenna size is related to frequency,5gantenna or 64 channel antenna According to the principle of wireless communication, in order to ensure the highest conversion efficiency of antenna transmission and reception, the distance between antenna oscillators must be greater than half of the wireless signal wavelength, and the wireless signal wavelength is inversely proportional to the wireless signal frequency (λ = C / F, where C is the speed of light, f is the wireless signal frequency), that is, the higher the signal frequency, the smaller the signal wavelength. In the future,5gfrequency band inChinawill be mainly 3.5GHz and 2.6GHz. According to this frequency band, half of the wavelength is about4.3cm/5.8cm. According to the current5gtest, the 64 channel massivemimo technology is the mainstream test choice of various equipment manufacturers. Although the more channels, the higher the performance of the network, but considering the size / weight of the antenna, antenna performance and cost factors, the current operators are also considering the low-cost massivemimo scheme - 16 channels. In our opinion, if the cost of 64 channel antenna in the early stage of5gis not reduced to the range accepted by the operator, the operator may give priority to the 16 channel scheme when the deployment and capacity are met. Screenshot9.23.33 amFebruary 28, 2019 The5gbase station architecture has changed greatly, and the trend of antenna active is obvious 4GHongji station is mainly divided into three parts: antenna, RF unit RRU and baseband processing unit BBU deployed in the computer room. 5gnetwork tends to adopt the new wireless access network architecture of AAU + Cu + Du, as shown in the figure below. The antenna and RF unit RRU will be combined into a new unit AAU (active antenna unit). Besides RRU RF function, AAU will also include some physical layer processing functions. Screenshot9.24.35 amFebruary 28, 2019 In the age of5g, the increasing number of antenna channels and the active antenna have put forward higher requirements for an...