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What is a Cell Phone Repeater?

What is a Cell Phone Repeater?   A cell phone repeater (also known as cellular repeater, amplifier, or cell signal booster) is a device used to improve cell phone reception in an indoor outdoor environment. A cell phone repeater is typically made up of three primary components: A "donor" antenna - also called a "reception" antenna A bi-directional signal amplifier One or more rebroadcast antennas Cell phone repeaters are most often installed inside buildings, and are used to bring signal from outdoors into the structure, negating attenuation of RF signal caused by the building materials. In-building cell phone repeater systems typically use an outdoor donor antenna to transmit and receive signal from the nearest cellular signal. The outdoor donor antenna is connected via coaxial cable to an amplifier unit which amplifies the signal, and retransmits it locally via one or more indoor antennas, providing improved signal strength inside the building. Smaller cell phone repeaters are also used inside vehicles, boats, and recreational vehicles to improve reception for users. For more information on available cell phone booster kits and antennas, read our cell phone booster guide. How Cell Phone Repeaters Work The active component of cell phone repeaters is the bi-directional signal amplifier. A bi-directional amplifier amplifies signal in both the uplink and downlink directions. This allows cell phones served by the rebroadcast antennas to both send and receive data from nearby cell towers. A bi-directional amplifier typically contains the following components: Diplexers or power splitters to split signal into multiple bands. Duplexer filters to separate the uplink and downlink blocks within bands. Amplifiers The block diagram below shows a typical layout of a dual-band bi-directional amplifier:   Requirements for Operation In order to use a cell phone repeater to improve signal coverage, two primary requirements must be met: Adequate donor signal Adequate isolation between donor and rebroadcast antennas Adequate donor signal All RF amplifiers add noise to the existing noise floor from the donor signal. The additional noise added by an amplifier is referred to as its "noise figure." For most amplifiers, this is between 6 dB and 8 dB. In order for a cellular repeater to operate correctly, the signal-to-noise ratio (SNR) of the donor signal must be greater than the noise figure of the amplifier. Without adequate signal at the donor antenna location, no improved signal will be experienced by users. Isolation between antennas For correct operation of a cellular repeater, the isolation between the donor and indoor antennas must be greater than the gain of the amplifier. If adequate isolation does not exist, amplifier feedback effects will cause "oscillation." In the US, the FCC requires that all consumer-rated boosters include automatic gain control (AGC). AGC reduces the gain of bi-directional amplifiers to ensure that the amplification is always lower than the path loss isolation between the outdoor an indoor antenna. The FCC requires that If a device is unable to control oscillation effects by utilizing AGC, it must detect the oscillation and automatically shut down.



Minor problems that may be encountered after the installation of the mobile phone signal amplifier

Detailed description of the adjustment of the mobile signal amplifier:   1. The indoor antenna installation should be away from the outdoor antenna to prevent mutual influence. Indoor antennas need to be separated from outdoor antennas by walls. 2. The indoor antenna should be installed at an angle of 2 meters above the interior wall of the house or inverted on the ceiling ceiling. 3. All kinds of connectors must be wrapped with adhesive tape to prevent water seepage from being oxidized, resulting in a smaller coverage of data signals in the house.   Common failures of mobile phone signal amplifiers:   First, after installation, there is no practical effect at all 1. First check whether the display light on the amplifier server can be lit to determine whether the power can be connected 2. Then clarify whether the selection of spare parts such as amplifier servers and wireless antennas can be appropriate, and whether they can be paired with the type of mobile phone card they are using;   3. Determine whether the indoor and outdoor sockets, regulators, and wireless antennas of the amplifier server can be properly connected. Second, after installation, the data signal is improved, but no phone calls can be made   1. Make sure the outdoor antenna is installed properly; 2. Determine that the data signal is stable at the location of the outdoor antenna, and the orientation of the wireless antenna is as biased as possible to the data signal transmission communication base station; 3. Determine the length of the data signal transmission line of the outdoor antenna and the amplifier (preferably not more than forty meters, not less than ten meters);   4. How to never get it, adjust the amplifier with higher power or ask a professional operator to check it comprehensively. Three. , The call sound quality is not very good 1. Adjust the orientation of the outdoor antenna so that the orientation of the wireless antenna is as biased as possible to the data signal transmission communication base station; 2. Change the movement of the data signal transmission line from the outdoor antenna to the amplifier server (the approaching straight line, the route cannot be turned too much, and the right angle of 90° cannot be turned); 3. The route from the outdoor antenna to the amplifier server should be coaxial above 50 ohm-7D as much as possible;   4. Determine whether the distance between the outdoor antenna and the indoor antenna can be too close (too close will generate self-excitation), the specification spacing is above ten meters, it is best to have walls, stairs and other objects isolated, and it is proposed that indoor and outdoor wireless antennas cannot be installed on the same level, to avoid the data signal sent by the indoor antenna is received by the outdoor antenna to generate infinite loop expansion (self-excitation).   Fourth, the data signal has been improved after installation, but the coverage is not large 1. Determine the part where the outdoor antenna is installed has sufficient data signal and strong signal; 2. Make sure that the data signal transmission line from the indoor antenna to the amplifier server is not easy to be too long, the route connector is properly intact, the route raw materials meet the regulations, and the regulator is not connected too much; 3. Appropriately install indoor antennas according to specific conditions; 4. Choose a mobile phone signal amplifier with greater output power.  



Mobile phone signal booster manufacturers tell you why a full signal is not worth a block?

  When the data signal grid is lower than 3 bars, everyone will involuntarily feel that the current data signal is not good, maybe this is not the case.     For example, are in the elevator, some people's mobile phone signal has 1 bar can still chat and talk on the phone, maybe the 3 data signals of the mobile phone icon sent to WeChat Moments but always can not be forwarded.   There are many such reasons that occur, but one misconception must be corrected first, and the data signal grid does not necessarily represent the mobile phone signal. Each mobile phone has a different optimization algorithm for the data signal grid, which is why the above situation occurs. Even if the data signal grid does not represent the mobile phone signal, what are the uses of the mobile phone signal grid? The original intention of the data signal grid setting is to indicate the current data signal status of the mobile phone, and the Internet will select the best communication frequency and entrance for the mobile phone.   If you choose a mobile phone that is suitable for multi-frequency points in areas with more people, the mobile phone signal will jump to the frequency point where the number of access times is relatively small. Therefore, even if consumers' mobile phones use the same network operators and are connected to the same mobile phone towers as the mobile phones of ordinary users in the surrounding areas, the number of data signal grids indicated on the mobile phone may not be the same.     In terms of removing external influences, a large number of data signal grids do represent better data signals, in fact, the number of data signal grids is only for reference, and cannot be used as a specification to judge the advantages and disadvantages of data signals. Mobile phone signal booster|How does the mobile phone signal grid change?     The key to the change of the mobile phone signal grid lies in the data signal optimization algorithm embedded by the manufacturer for the mobile phone signal, and the key to the change of the data signal grid is the refresh rate of the data signal optimization algorithm. If the data signal update optimization algorithm embedded in the mobile phone is very fast, the data signal changes rapidly, and vice versa, the data signal changes slowly. This means that if ordinary people use the mobile phone signal grid to find the part of the data signal and better data signal, it is very likely to waste a lot of time.     The above problems our professional mobile phone signal booster manufacturers recommend that you use our ATNJ mobile phone signal booster can easily solve these problems.   Shenzhen ATNJ Communication Technology Co.,LTD is a professional organization specializing in solving mobile phone signal poor, mobile phone signal booster and mobile phone voice communication faults for factories, hotels, villas, clubs, bars and other social places, serving Guangdong Province.



What is the fundamental difference between 5G and 4G?

With the progress of science and technology, people pursue a better life and better and better network experience, from 2G to 3G and then to 4G. Now many countries and regions begin to use 5G network, and even some countries are studying 6G. What's the difference between 4G and 5g? In short, it is a fast! G is the abbreviation of generation, which means the era. Since it is an era, the difference is great. We can't just talk about speed. Of course, speed is also one of the very important dimensions. ATNJ Mobile Signal Repeater.pdf   1. Speed. 5G and 4G will have huge differences in transmission speed. If you don't know what the huge difference is, you can compare the previous green car with the current high-speed railway. The current high-speed railway will make medium and short distance travel give up aircraft. However, in the era of green train, there are aircraft. If the economy allows, few people will give up aircraft. 2. All things are interconnected. If you plug a mobile phone card into your car in the existing 4G network, it can be driverless. Even if vehicle identification, obstacle identification and other technologies pass, it may not start well. In the 5g era, all things are interconnected. Many driverless cars send online signals to each other. With the instant sending of various low delay signals, driverless will be safe for more people to use in the 5G Era.   3. Communication standard: according to Moore's law, when the price remains unchanged, the number of components that can be accommodated on the integrated circuit will double every 18-24 months, and the performance will also double. The 4G standard has been launched for so long, and the existing communication methods and rates are designed based on 4G. However, the current hardware development speed is so fast that the existing network inevitably can not fully keep up with the speed of hardware upgrading. After such a long time of development, China, now the world's largest communication consumer, can better meet the needs of the future in the new era, and the starting point of the standard is higher, Compared with the 4G standard, it is subversive. Such network speed has brought great convenience to our life and work. The difference between 4G and 5g lies in the fast and slow network speed, high implementation efficiency and time saving.



The difference between TDD and FDD

1. Duplex mode TDD: Time Division Duplex. The transceiver shares one RF frequency point, and the uplink and downlink use different time slots for communication. FDD: Frequency Division Duplex, which uses different RF frequency points for communication.   2. Speed Theoretically, under the same bandwidth conditions, such as 10m + 10m allocated by FDD and 20m allocated by TDD, the rate of TDD will be lower than that of FDD. The main reason is that there is a frame called special subframe in the frame structure of TDD. Some of these frames will be wasted (such as the protection time slot) and will not transmit any data, and there is no such complete waste of FDD frames.   3. Coverage TDD-LTE is suitable for hot area coverage, and FDD is suitable for wide area coverage An early Qualcomm report showed that under the condition of the same frequency and power, FDD can provide better coverage than TDD. TDD coverage is 80% (DL / UL = 2:1) / 40% (DL / UL = 1:1) less than FDD. One of the main reasons is that the transmission time of uplink power (TDD) is shorter than that of uplink power (TDD). 4. Moving speed of mobile station FDD is a continuous control system and TDD is a time separated control system. When moving at high speed, Doppler effect will lead to fast fading. The higher the speed, the higher the fading transform frequency and the deeper the fading depth. Based on the current chip processing speed and algorithm, when the data rate is 144KB / s, the maximum moving speed of TDD can reach 250km / h, which is still a certain gap compared with FDD system. Generally, the moving speed of TDD mobile station can only reach half or even lower than that of FDD mobile station. ATNJ Mobile Signal Repeater.pdf



What are the disadvantages of 5G?

  ATNJ Mobile Signal Repeater.pdf Advantages of 5G (1) Speed 5g has a theoretical speed of up to 20 Gbps, and its data rate is several orders of magnitude higher than 4G and 4G LTE. The actual speed that enterprises can achieve depends on a variety of factors, including the proximity to communication towers, the technical complexity of communication operators themselves, and whether network components have been designed to support Gigabit performance. In other words, 5g will enable enterprises to use services that cannot be provided by the original standards, such as automation and advanced video conferencing functions. 5g not only provides higher speed, but also provides what may be more important: low latency. (2) Low delay According to some experiments, 5g significantly reduces the time required for network devices to respond to commands (usually less than 5 milliseconds). Regardless of location, applications and services will work in the same way, eliminating delays that affect real-time communication. (3) Capacity 5g supports connecting much more devices than 4G at the same time, which is estimated to be even as high as 100 times. Therefore, enterprises no longer need to evaluate their cellular and Wi Fi wireless strategies as one or more proposals. With 5g, enterprises can switch between cellular and Wi Fi connections as needed without worrying about the impact of performance or the limited accessibility of mobile broadband, especially in densely populated environments such as Manhattan and other major urban areas. (4) New generation services based on artificial intelligence and machine learning 5g will promote the rise of a new generation of interactive services based on artificial intelligence and machine learning. For example, video conferencing with augmented reality or virtual reality can simulate the environment and help enterprise executives make better project decisions. Automation will enable enterprises to rely on applications and services that are more responsive and predictive than they are today. (5) Rethinking the Internet 5g will become the driving force leading enterprises to rethink the network. Branches of enterprises can use 5g as the main connection medium and adopt Internet services provided by multiple communication operators through SIM cards. Whether you work centrally in the enterprise or remotely from home, you can take advantage of additional automation and security functions. Because 5g compatible components can quickly process and respond to requests, reducing the need for data center backhaul, edge computing will become more important.   Disadvantages of 5G (1) Security 5g transmission security algorithm is more comprehensive than the algorithm supported by 4G standard, but enterprises may encounter other network security problems. As network attackers try to exploit vulnerabilities, a large number of IOT devices and components connected to 5g network will greatly increase the threat faced by enterprises. 5g devices themselves may also attract their attention because the chips and other components designed to drive these devices may be infected with malware by network attackers. Enterprises also need to carefully weigh the technology that their 5g networks use network slicing (a technology that creates a virtual network to host dedicated applications or services). Vulnerabilities in any part of the infrastructure of communication operators may cause serious security problems in the whole network. For enterprises with low risk tolerance, dedicated 5g network may be the best choice. (2) Capex / OPEX In order to fully enjoy the benefits of 5g, enterprises must upgrade and replace network components and adopt processors that support higher speed and performance indicators. It is expected that communication manufacturers will launch 5g compatible devices early next year, but enterprises will have to strive to find ways to maximize 5g investment, because most of their network infrastructure still depends on traditional devices. Its price will be a key consideration because the pricing of operators and equipment is still changing. (3) Uneven coverage Although communication operators continue to invest in 5g, 5g will not be covered in many parts of the United States for a long time. Enterprises with offices in rural areas may be particularly vulnerable to 5g coverage gaps and will have to rely on a combination of traditional network connectivity technologies. Therefore, those enterprises that cannot access 5g may be forced to wait for a period of time before communication operators can provide 5g services in their region, which may be affected by the competition of other operators. (4) Line of sight / penetration problems 5g high-frequency signals are more likely to be blocked by objects, so ensuring the coverage of enterprise offices and factories is always a problem. Enterprises may have to redesign and build some facilities to ensure adequate services or build supplementary radio spectrum networks (such as those based on citizen broadband radio service spectrum), which will enable them to expand the coverage and capacity of 5g networks. (5) Hype factors Operators and suppliers claim that many enterprises may be overwhelmed by how 5g will affect their operations. They have to spend a lot of time fully understanding how they intend to use 5g to get the maximum return and how to prove the required return on investment (ROI). 5g is different from other technologies initially driven by enterprises and then adopted by consumers. When 5g is adopted, the wide adoption of enterprises will be postponed until 5g compatible devices are more widely used, and the real 5g services are provided by operators. The relevance of 5g will only appear when this standard (such as coverage, price points and supported devices) is ubiquitous.



Why is 5G displayed on the mobile phone but the actual network speed is very weak?

1, Too much signal interference and other mobile signal would interfere with 5G signal in the transmission process, so some of the received signal is affected by interference. 2, At present, most of 5G base stations are NSA base station, but SA 5G station is much better. Now many countries requires their signal operators to build SA 5G station, but it takes a lot of work and time. 3, 5G has typical features, high frequency and short wave, which makes it small signal transmission range and insufficient penetration ability. Therefore, in some areas with high-rise buildings, if the construction of 5g base station is insufficient, 5g signal will be affected, which is also the reason why there is a big gap in network speed in different places. 4, The higher the frequency band of wireless signal, the faster the data transmission speed, but the greater the signal attenuation. Almost all 5G frequencies are above 3G(3.4-3.6G, 4.8-4.9G), but 4G frequencies are between 1.8G and 2.3G. Therefore, the 4G signal attenuation is not big, and has a longer transmission distance and has a larger coverage. 5, Due to a smaller coverage of 5G, its stability would be affected by the moving speed of mobile users. Once the moving speed is too fast, the mobile signal received would be transferred from the current base station to another base station immediately, affecting the 5G signal use. 5G signal coverage is also affected by the geographical environment. For example, we assume a 5G base station can cover a radius of 100 meters, but with the influence of buildings, mountains, trees, the actual coverage will be smaller. ATNJ Mobile Signal Repeater.pdf



Basic knowledge and working principle of mobile signal repeater

Why is mobile signal repeater needed? There are four main reasons, 1, With the rapid development of mobile communication industry, the number of mobile communication users is increasing, so that the cellular network planning is getting smaller and smaller, the location of base station is getting lower and lower, and the signal coverage is getting smaller and smaller; 2, With the development of urban construction, high-rise buildings continue to emerge. Based on the shadow effect of wireless communication, the signal blind area of mobile communication will be formed behind or in the middle layer of these high-rise buildings 3, During the construction of cellular mobile signal base station, in order to avoid the interference of adjacent cells, the main lobe of its antenna radiation pattern has a large dip angle, so that the middle and upper parts of high-rise buildings can not receive signals effectively 4, Due to the shielding effect of buildings on electromagnetic waves, some closed large buildings can not receive mobile communication signals normally, such as tunnels, subways, underground shopping malls, parking lots, hotels and office buildings. Mobile signal repeater is to solve the above four problems. As long as a set of mobile signal repeater is installed in a specific place, the signal of the whole range can be amplified well, bringing great convenience to the staff or guests. Mobile signal can effectively solve the problem of weak signal, such as in tall buildings, office buildings, basements, restaurants, villas, elevator, etc. ATNJ Mobile Signal Repeater.pdf Basic knowledge of mobile signal repeater 1, Is the interference of mobile signal repeater large to base station? Radio waves from mobile signal repeater would interfere to the base station. Generally the interference of mobile signal repeater with power 100mW can be ignored. Higher of the power and closer to the base station, the greater of the interference. 2, Is the radiation of mobile signal repeater harmful to human body? Any electronic device has a certain amount of radiation. The higher the power of the equipment, the greater the radiation. Generally, there would be a large radiation from device with power over 5W (37dBm). Power of a general mobile signal repeater is within 200mW(23dBm), and after it is transmitted to indoor antenna, power is 5mW(7dBm), and the radiation to human body is even less than that of household appliances. Without mobile signal repeater, the radiation power can reach 1W (30dBm) in weak signal environment while making a call,. With ATNJ mobile signal repeater, the radiation power is low to 10mW(10dBm) while making a call, that is after installing ATNJ mobile signal repeater in the poor signal environment, the radiation of mobile phone is greatly reduced during a call.   Working principle of mobile signal repeater Downlink: Outdoor antenna receives signal from base station, and after amplified by mobile signal repeater, signal would be transmitted to indoor antenna. Indoor antenna would spread signal to users’ mobile phone. Uplink: Users’ mobile phone transmits signal, which would be received by indoor antenna, and transmitted to mobile signal repeater. After signal is amplified by the device, it would be transmitted to the base station through outdoor antenna.



Is signal repeater harmful to people?

Nowadays, 5G mobile phone is becoming more and more popular and almost everyone has one. The main function of a mobile phone is to make a call, and the most important thing is stable signal strength while making a call. WiFi wireless network signal, which is amplification of mobile phone signal function, is covering in many places such as public places, and private home. I think there should be a lot of people who know about mobile signal repeater, but I don't know how many of them know its working principle. People always worry that the radiation of electronic equipment will do harm to human body This article is to tell you the basic characteristics of mobile signal repeater and to solve the question: is a mobile signal repeater harmful to human body? ATNJ Mobile Signal Repeater.pdf The electromagnetic signal strength from a mobile signal repeater is very weak. As long as the mobile signal repeater is qualified and produced by regular manufacturers, and its electromagnetic radiation intensity is tested by the national authoritative testing organization like National Institute of Environmental Health China CDC, all samples of electromagnetic signal strength tested is lower than the limited value in GB8702-88 of “Regulations for electromagnetic radiation protection” stipulated by State of Environmental Protection Agency (This standard in DB8702-88 is only 1 / 5 of the European standard), it won’t do any harm to human body. Therefore, there is no need to panic. The power of a mobile signal repeater is very small (≤ 1W), and its working range is around 20-meter to 30-meter diameter, which will not cause any interference to the base station. In addition, mobile signal repeater is only used in some specific occasions, and its impossible to endanger public information security. The frequency of electromagnetic signals sent from a mobile signal repeater is completely in the working frequency band of mobile phones stipulated by our country. The signals are always in a relatively static and constant state, and will not affect any other electronic equipment, interfere with human brain, nor affect human normal thinking.



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