Category: NEWS

It has been nearly a year since the development of special military operations between Ukraine and Russia. During this year, we can often see an interesting phenomenon on various news channels: the two sides have sent various styles of drones to the battlefield , DRONEs attack each other in a variety of ways, and have also produced a lot of combat results, but then some people have such doubts, in the process of Ukrainian and Russia using drone s to fight each other, could it be There is nothing to do with these flying drones? After almost a year of special military operations on both sides, why do we see so little news about the use of drone jammers?

The main reason why drone s can be popular in the battlefield environment is because of their small size and exquisite size, and their ultra-low altitude flight makes it difficult for ground radar to detect and identify them. At the same time, they can fly at low speed or even hover. , then the DRONE only needs to be kept three or four hundred meters away from the soldiers, and it can be almost completely undetected. Even worse: Even if it is discovered, it is basically an impossible task to shoot it down with guns or artillery. In view of this situation, in fact, the best way to attack drones is to use drone jammers.

Why is it said that using drone jammers is the best way to combat drones? That’s because the target of drones is indeed too small, and it is definitely difficult to accurately aim and shoot them down with conventional weapons. However, drones are not without weaknesses. Its weakness is that most drones are operated by operators. For remote control, and remote control must involve the transmission of wireless communication signals, the drone jammer is to grasp this key point, focusing on the precise interference of the signal transmission link of the drone. If signals such as flight control and navigation positioning are disrupted by interference signals, the drone can only lose its target and fly around like a headless chicken, or even fall directly to the ground and be damaged.

Going back to the original question, why is there so little reported use of drone jammers in Ukrainian-Russian special military operations? This is mainly due to two reasons: the first is that Ukraine and Russia have not paid much attention to the field of drone jammers in recent years, especially Ukraine, which can be said to have no ability to produce drone jammers by itself. Although Russia has certain research and development capabilities, it is obvious that the production of drone jammers cannot be guaranteed, which makes it impossible to be widely used on the battlefield. The second reason is that news reports require supporting materials for images, and drone jammers are usually secret weapons belonging to the hidden front. Due to the need for confidentiality, any party participating in the war is not willing to take the initiative to disclose the equipment in this regard application.

Often when someone calls us to express their needs, they directly state their purchase intention at the beginning: they need to purchase a set of high-power mobile phone signal jammers, and they need to rely on this jammer to solve the signal shielding of all rooms in the entire building. . At the same time, we also need to tell us where the jammer should be installed in the building. In response to the customer’s needs, we must also patiently understand the specific situation of the project site, and the final recommended plan is often quite different from the customer’s original idea. how so? Why don’t we recommend high-power mobile phone signal jammers for use in indoor environments?

To solve the signal shielding of all rooms in a building is actually to carry out signal shielding for the indoor environment of this building. If there are several independent rooms in a building, the best solution is to use multiple low-power mobile phone signal jammers in the form of cellular network coverage.

The main purpose of the high-power mobile phone signal jammer is to solve the signal shielding in open outdoor environments or open areas. Generally, it is required to choose the installation position of the high-power mobile phone signal jammer as high as possible, so as to achieve the maximum transmission distance. Only when the installation height is high enough, can the obstacle be crossed as far as possible and the shielded signal can be transmitted farther. And once a large building is encountered during the transmission, the transmission of the shielded signal will basically be terminated.

Going back to the problem of using a high-power mobile phone signal jammer to solve the signal shielding of a building, the first thing to know clearly is: for the coverage of a building’s shielding signal, a high-power jammer must never be installed in this building. In the building, because the dense walls in the building will seriously affect the transmission of the shielding signal, the shielding signal will not be able to directly cover the upper and lower floors, and even the number of rooms that can be covered on this floor will be extremely limited. Then someone may ask, what if the high-power mobile phone signal jammer is installed directly on the roof of the building? This doesn’t work either! Because if it is installed in the center of the roof of the building, its shielding signal mainly affects only the top of the building and some areas around the building, and the interior of the building below its installation position will be affected by the reinforced concrete on the top of the building. The impact of the wall makes it impossible for the shielding signal to be transmitted to the various rooms in the building below.

If it is determined that high-power mobile phone signal jammers must be used to solve the signal shielding of a building, there are still solutions, but it is almost impossible to use only one set of high-power jammers, but must use at least 2 sets or more Only high-power mobile phone signal jammers can be used in combination. The specific implementation method is: install a set at the front and back of the building at a distance of about 20-30 meters, and the installation height should preferably reach half the height of the building. If the length of the building exceeds 50 meters, the number of jammers installed will have to be increased.

At the beginning of the new year, in order to welcome the college entrance examination in June and the senior high school entrance examination in July, many schools that will be used as examination rooms have already started to construct standardized examination rooms. According to the construction standard of the standardized examination room, the mobile phone signal jammer system is a project that must be built well. However, when the customer demonstrates the scheme of the jammer system and selects the equipment, he will find that there are two technical solutions. The first one It uses conventional low-power mobile phone signal jammers to cover the jamming signals in the form of cellular networking. The second is to share the host of high-power jamming equipment, and the antenna transmitter adopts the indoor signal distribution method. Each classroom in the classroom is covered by interference signals. Then the question arises: facing these two technical solutions, how should customers choose? What are the advantages of the indoor signal distribution scheme of the mobile phone signal jammer system?

The process of building a mobile phone signal jammer system in the first way of cellular networking mentioned above is relatively simple and easy to understand, so we won’t describe it too much. Focus on analyzing the advantages and disadvantages of using the indoor signal distribution method.

First of all, let’s talk about the advantages: the host device of the mobile phone signal jammer system will be installed in a relatively hidden location, which is convenient for independent maintenance and repair. The antenna end usually adopts a small omnidirectional antenna, which is installed on the ceiling in corridors or classrooms. The size of the antenna is small and inconspicuous. If there is a gypsum board ceiling, it can also be installed inside the ceiling to achieve complete concealment. For the construction of a mobile phone signal jammer system for a teaching building, the number of hosts required is relatively small. A host can usually solve the signal interference of multiple classrooms on the 2nd or 3rd floor.

Let’s look at the disadvantages again: if the indoor signal distribution scheme is adopted, the hosts of the system are all high-power devices, and the cost is relatively high. The purchase cost of a high-power host is almost equivalent to dozens of low-power mobile phone signal jammers. If a teaching building has a height of 4-6 floors, it will need at least 2 high-power hosts. If the length of the building is relatively long, the number of hosts required may double. This will undoubtedly increase the construction cost a lot. The way of indoor signal distribution During the construction process, the remote transmitting antennas are connected in parallel to a main feeder, and this main feeder is finally connected to the system host, and there is always a cable connection between the main feeder and each examination room , then there must be construction work for system wiring, wall penetration, and hole drilling. And there is another phenomenon that needs to be paid attention to. For several transmitting antennas connected in parallel on the main feeder, from near to far, the strength of the interference signal that each antenna terminal can obtain is a process of gradual attenuation. The antenna at the end can receive a strong interference signal and transmit it, while the antenna at the far end will be greatly reduced, which will make each examination room and classroom in the mobile phone signal jammer system show different final interference effects.

The gun-shaped drone jammer is used as the last weapon of drone defense. Some customers may have doubts during use: in the actual application process, if an incoming drone is actually found, use When using a gun-shaped drone jammer, is it necessary to keep aiming at the drone for precise strikes?

The customer who raised this question is obviously a little overwhelmed. Although the overall appearance of the gun-shaped drone jammer adopts the appearance design of a firearm, and most of them are equipped with scopes, in actual use, it is different from the commonly known military firearms: it does not Aiming in the strict sense is required. The sighting equipment configured on the gun-shaped drone jammer is only for auxiliary observation, and it can even be used as a decoration.

Why is there no need to think about precisely aiming the gun-shaped drone jammer at the drone? This is because it works completely differently from regular firearms. Conventional firearms fire bullets and hit the target, thereby causing killing or destructive effects. But the gun-shaped drone jammer does not fire bullets, it emits jamming signals, which are radio waves, which cannot be seen or touched. The interference signal is emitted through the directional antenna built in the front end of the gun-shaped drone jammer. Although we cannot see the shape and coverage area of the interference signal after it is emitted, it can be described in general as follows: jamming with a gun-shaped drone The muzzle of the detector is the initial position, and the jamming signal is basically emitted to the far end in a shape similar to a horn. The cone angle between 15°~30°.

When the user recognizes with the naked eye and finds that a drone has invaded the area that needs to be protected, in fact, he only needs to point the gun-shaped drone jammer in the general direction of the drone’s attack, and there is no need to accurately aim at the time. Even if there is a clear deviation in the direction the gun-shaped drone jammer is aiming, as long as the deviation angle is not too outrageous, its jamming signal will still have a very effective jamming and strike effect on the drone.

In a few months, the annual college entrance examination and high school entrance examination will be ushered in. Every few days before the arrival of the examination season, people who are near the school examination room will usually receive text message reminders, reminding them of the time during the examination period. Within a few days, due to the installation and use of mobile phone signal jammers in the examination room, mobile phone users within a certain range around the school will affect normal mobile phone communication to varying degrees. Then the question arises: What kind of impact is the impact on mobile communication mentioned here? What is the scope of influence of the mobile phone signal jammer in the examination room?

First of all, what we need to know is: in the classroom of the school’s examination room, the mobile phone signal jammer installed will not be turned on during the normal teaching period, so in normal days, the mobile phone users around the school will not feel anything special impact. Only when facing the college entrance examination or high school entrance examination, in order to maintain the fairness of the examination and effectively prevent electronic cheating, will the examination room type mobile phone signal jammer be turned on during the examination.

Ordinary people who live near the school observe their mobile phones during school exams, and they can feel the impact including: the mobile phone signal sometimes disappears, or even directly sees that the signal on the mobile phone disappears completely. When using a mobile phone to make and receive calls, there will be intermittent situations, and in extreme cases, the phone may not be able to be dialed at all. Similarly, due to the influence of mobile phone signal jammers in the examination room, when using mobile phones to surf the Internet or watch videos, there may be freezes and data cannot be refreshed. When using chat software, there may be frequent delays in receiving and sending messages, etc.

The above is the situation that may affect the normal use of mobile phones around the school, so how big is the scope of influence of the mobile phone signal jammer in the examination room? This has to be looked at in two situations: the first situation is under normal circumstances, if only the school has turned on the mobile phone signal jammer in the examination room, due to the large number of mobile phone signal jammers working at the same time, although it is enough for all the examination room Classroom signal shielding requirements, but they will also unintentionally affect the surroundings of the school, and the range of influence generally reaches one or two hundred meters outside the school wall. The second situation is that the local communication operator may respond to the notice of the education authority and temporarily close several mobile phone base stations near the school. In this case, the affected area will be greatly expanded, depending on the number of closed base stations And the range they usually cover, specifically, this range may reach hundreds of meters or even thousands of meters.

As we all know, prisons are places where inmates are detained, and mobile phone signal jammers are installed in prisons to prevent inmates from making illegal contacts with the outside world. This point can be understood by ordinary people, but in recent years, why is it necessary to install unmanned signal jammers in prisons? What about machine jamming devices?

Prisons are relatively special places, usually built in relatively remote places, and ordinary people generally do not take the initiative to approach prisons, but there will be a small number of curious people who use drones to secretly fly to prisons Nearby, in order to satisfy a little bit of curiosity. For this kind of privately flying drones close to the prison, there is not much malice in the motive, but the prison is definitely not allowed. By turning on the drone jamming device, this kind of harassment can be easily prevented from happening.

The above-mentioned situation will not have serious consequences for the prison. The biggest demand for installing drone jamming equipment in the prison is to prevent the illegal intrusion of some special-purpose drones. From the analysis of the prison’s conventional security measures, patrol posts have been deployed within a considerable distance inside and outside the prison walls, and there will also be modern monitoring and alarm equipment, but these are only protective measures for ground activities. With the proliferation of commercial small drones, the airspace protection above prisons has become a weak link in prison security. Just imagine, if someone airdrops items into the prison by drone, what kind of consequences will this bring? UAVs can overlook the detailed situation inside the prison at high altitude. What should we do if we use this information to plan and guide the escape behavior of prisoners inside the prison?

It is obvious that when faced with the illegal approach of drones, prison managers will have the possibility of multiple threats. In this case, the best solution is to install drone jamming equipment in the prison. Once found If a drone approaches maliciously, it can be driven away without hesitation. Of course, the current drone jamming equipment, in addition to driving away drones, can also force-land these drones to capture them.

Sometimes, we will receive inquiries from school leaders or teachers: we hope to purchase a batch of mobile phone signal jammers for the examination room, so as to prevent students from cheating in the exam by using wireless communication work during the exam. However, additional requirements are put forward: it is required to be able to identify and distinguish the mobile phone numbers in the examination room. The ideal effect is to block the signal only for the mobile phone numbers of the students, while the mobile phone numbers of the teachers can be used normally. It is equivalent to defining the mobile phone number of the students as a blacklist, and defining the mobile phone number of the teacher as a whitelist, then the question arises: Does the mobile phone signal jammer in the examination room have the management function of blacklist and whitelist?

It is a pity that the conventional mobile phone signal jammer in the examination room is 100% sure that it does not have the management function of blacklist and whitelist. Analysis from the technical principle: currently in the scope of application in the examination room, the mainstream mobile phone signal jammer is just an electronic device that can emit white noise interference signals. It uses power suppression to prevent the mobile phone from forming a normal and effective communication with the base station. Communication connection, so as to achieve the effect that the mobile phone signal is shielded. However, if it is necessary to identify the numbers of mobile phone users within a certain range, and further classify and manage these mobile phone numbers, that is, to distinguish them by blacklist and whitelist, then such a product must first have signal reception and The ability to analyze and process, and at the same time, it also needs to be able to support the analysis and identification of multiple communication operators and multiple mobile phone standards. As mentioned earlier, our common mobile phone signal jammers in the examination room only emit interference signals and have no receiving components at all, so it is completely impossible to implement blacklist and whitelist management functions.

Then the customer will continue to ask: Since our test room mobile phone signal jammer cannot do the blacklist setting and management functions, is there any electronic product that can realize this function in reality?

In reality, there is indeed a system device with blacklist and whitelist management functions, but it will not be called a mobile phone signal jammer. The correct name should be called: mobile phone signal management and control system. However, this system is a bit similar to a pseudo-base station. It is usually only authorized to purchase and use by the public security special police or some special management departments, and the purchase price of a system is not low. If the school purchases such products for the construction of standardized examination rooms, Is it feasible? It’s still up for debate.

At present, as long as it is a relatively formal or high-profile examination item, it is already commonplace to install mobile phone signal jammers in the examination room. The purpose is to prevent candidates from secretly using mobile phones during the examination. and other wireless communication tools for illegal cheating. Over the years, from time to time, some candidates or parents will ask such a question: worry about whether the shielding signal emitted by the mobile phone signal jammer has strong electromagnetic radiation after it is turned on and used? Will this affect the examinee’s normal answering process? Then the question arises: Does the mobile phone signal jammer used by the school in the exam have electromagnetic radiation?

First of all, it is necessary to correctly distinguish the difference between electromagnetic radiation and nuclear radiation. In fact, when many people hear the word “radiation”, they will feel fear and fear, and always want to avoid it. But in fact, these people confuse the concepts of electromagnetic radiation and nuclear radiation in their initial impressions, and even treat the two types of radiation directly and equally, which is completely wrong.

Electromagnetic radiation and nuclear radiation are two completely different situations. The harm and influence of nuclear radiation are indeed huge and long-lasting. But nuclear radiation is not common. Electromagnetic radiation is different. Only when the intensity of electromagnetic radiation reaches a certain level can it have an impact on human health, and electromagnetic radiation is very common. It can even be said that electromagnetic radiation has always accompanied our daily life. The mobile phone signal shielding instrument is the wireless interference signal emitted, and its power supply, within a relatively short distance around the transmitting antenna, can indeed measure a certain value of electromagnetic radiation. But don’t worry, because the mobile phone signal jammer is an electronic product, and almost all electronic products produce electromagnetic radiation, such as the most common ones in our lives: mobile phones, computers, microwave ovens, TVs, printers, scanners, etc. . The only difference is that different electronic products have different intensity of electromagnetic radiation.

Refer to the public exposure derivation limit (power density of 0.4w/m²) issued by the state in the “Regulations on Electromagnetic Radiation Protection” (GB8702-1988), it can be known that as long as any electronic product can meet this electromagnetic radiation standard after testing, then There is no need to worry about the harm of electromagnetic radiation generated by this product. The same applies to mobile phone signal jammers.

Nowadays, as long as it is a regular manufacturer of mobile phone signal jammers, it will send the product to a regular product testing and certification unit, especially for testing such as whether the electromagnetic radiation is safe or not, the manufacturer will not take it lightly.

In order to prevent some criminals from using common commercial drones to engage in illegal activities such as sabotage, stealing secrets, and terrorist attacks, drone jammers are usually the first key defensive equipment. Then the question arises: What is the basic technical principle of the drone jammer? How does it interfere?

Most of the drone jammers currently on the market use high-power suppression, which means applying interference signals on multiple communication frequency bands of the drone, thereby cutting off the normal communication connection between the drone and the remote control.

The reason why drones can come and go freely to fly at low altitude, hover or perform shooting, delivery or other work tasks is inseparable from the controller using the remote control to control it remotely, and all control commands are through wireless communication. signal is transmitted. The drone signal jammer is to apply interference signals one by one to all the communication frequency bands that the drone may use, which allows the drone to be within the effective coverage of the interference signal, and the drone cannot obtain effective control.

The remote control signal of the drone includes not only the flight control command signal, but also the image transmission signal. In addition, the drone itself also has GPS navigation and positioning signals. Therefore, the interference signal emitted by the drone jammer is not only aimed at the communication frequency band of flight control and image transmission, but will also interfere with the GPS satellite positioning frequency band.

The above mentioned are only the more common drone jammers at present, because the technical principle of these high-power suppression methods of jamming signals is relatively simple, and the production cost is not high, so the purchase price of this type of drone jammer It is relatively cheap and can meet the requirements of customers for mass equipment and use.

In addition, there are a small number of drone jammers that use other technical principles, such as decrypting the communication protocol interface to directly crack the normal communication of drone s, or even take over illegal drone s. However, this type of drone jammer is rare after all, and the output is limited, resulting in generally high production costs and purchase prices. At the same time, this type of drone jammer cannot solve the communication protocol of any drone, and can only implement effective jamming behaviors against some known and a small number of decrypted drones. Therefore, their application scenarios are also subject to many restrictions.

In recent years, more and more customers have customized and purchased 5G jammers from us. On the one hand, some old customers have replaced and iterated the jamming devices in the original 4G era. Many application scenarios need to solve the problem by installing 5G jammers. Among them, some customers have asked us that the types of interference signals not only include all mobile phone signals, but also increase the interference function of GPS signals. Then the question arises, can 5G jammers interfere with GPS navigation and positioning signals at the same time? Woolen cloth?

Now almost all mobile phones have their own GPS navigation and positioning function, but it needs to be pointed out that the GPS mentioned here is just a traditional concept commonly known as the GPS navigation and positioning signal. Above, China’s Beidou satellite signals, European Galileo satellite signals, and Russian Gronass satellite signals are all called “GPS navigation satellite signals” by convention. The difference is that some mobile phones may support satellites from all countries. signal, and some mobile phones may only support satellite signals of some national stars. And whether the 5G jammers discussed in our article can interfere with GPS navigation and positioning signals at the same time obviously requires the inclusion of satellite navigation signals from all the countries mentioned above.

Most of the low-power 5G jammers currently on the market are installed and applied in indoor environments. Due to the obstruction of building walls, in indoor environments, most GPS satellite navigation signals are relatively weak, and sometimes even The GPS satellite positioning signal will be lost directly, so by default, the manufacturers of 5G jammers generally do not configure the signal jamming module of GPS navigation satellites when they leave the factory. Only when the customer puts forward a clear requirement that satellite signals also need to be interfered at the same time, the manufacturer will add a GPS signal interference module to the device.

About 15 years ago, mobile phone jammers in the examination room began to be used in the school examination process. In the past 15 years, with the upgrading of different mobile phone standards, it has already developed from the original 2G era to the current 5G era. The corresponding mobile phone jammer in the examination room is also undergoing simultaneous iterative upgrades. In addition to the continuous increase and compatibility of mobile phone systems, the school gradually began to advocate the entire system to have intelligent networking functions during the construction of the mobile phone signal jamming system project. Is it mainstream?

The real situation is indeed the case. Nowadays, when many schools are building new campus mobile phone signal jamming system projects, as long as the budget is not too low, almost all of them have begun to put forward such functional requirements: requiring the mobile phone jamming system to be integrated into the unified management platform of the campus network. Intelligent remote control and management of mobile phone jammers in examination rooms are required. Real-time monitoring and fault feedback are required for each jamming terminal in the mobile phone jamming system.

Now many schools have completed the platform construction of the digital campus, and the infrastructure of the internal campus network has also been perfected. The backbone network has been deployed to every floor of every building in the school, and even every classroom. This actually provides a very good network platform for the intelligent networking of mobile phone jammers in the examination room. As long as the jamming device has a network interface and data interaction functions, then building a fully functional mobile phone signal jamming system will become a matter of course.

Since the school’s original campus network is used, it is not necessary to go to additional network construction and deployment, saving construction costs. Examination room-type mobile phone jammers used to be stand-alone versions, but now these devices are required to add network communication modules. The cost is slightly increased, but fortunately, the increase ratio is limited after all. Moreover, once the online version of the mobile phone signal interference system is managed uniformly through the network, it will greatly facilitate the management personnel to control the overall system. At the same time, it will also greatly facilitate the real-time data feedback such as the maintenance and working status of the interference equipment. Reduce labor costs for managers. After a comprehensive comparison, it is relatively cost-effective to purchase the online version of the test room mobile phone jammer, which is one of the reasons why this type of product has become mainstream.

According to the 5G frequency band standard divided by the International Telecommunications Union (ITU), there are three 5G frequency bands, namely the low frequency band of 700MHz~3.8GHz, the middle frequency band of 3.8GHz~24GHz and the high frequency band of 24GHz~100GHz. Among them, my country uses low-frequency and medium-frequency bands, and a few European and American countries use high-frequency bands. When the mobile phone jammer in the examination room interferes with the 5G signal, it is aimed at the low frequency band and the middle frequency band of 5G to cover the interference signal. In the middle frequency band, our country allocates 4800 MHz~4960 MHz (abbreviation: 4.9G frequency band) to China Mobile China Radio and Television, then the question arises: Does the mobile phone jammer in the examination room include the 4.8G frequency band when it interferes with 5G signals?

To be honest, although most of the mobile phone jammers in the examination room can support signal interference in the 4.9G frequency band in the product manual, many of the mobile phone jammers in the examination room do not have the ability to interfere with the 4.9G frequency band in the actual products put into use. function. The reason is: 4800 MHz~4960 MHz is characterized by relatively high frequency, but serious signal transmission errors, and usually can only be used as indoor signal coverage. Compared with the low frequency band of 700MHz~2700MHz, or even the middle frequency band of 3.6G, the actual penetration rate and utilization rate of the 4.9G frequency band are very low. At present, only a few special places in China will use the 4.9G frequency band, and only It is used for private network communication. Therefore, as a manufacturer of mobile phone jammers in the examination room, knowing that the usage rate of the 4.9G frequency band is extremely low, and it is unlikely to deploy a mobile phone network with the 4.9G frequency band in a usage scenario like the school examination room, then give up Installing a 4.9G signal interference module will undoubtedly help reduce production costs.

Referring to the current development trend, even after two or three years, the 4.9G frequency band is still unlikely to be widely popularized and used in China. Even if the mobile phone jammers in the examination room do not have the jamming module of the 4.9 frequency band, there will be no incomplete 5G signal jamming during use, and customers basically don’t have to worry too much about the impact of this problem.

Of course, if the customer clearly requires the manufacturer to install a signal jamming module in the 4.9G frequency band before purchasing the mobile phone jammer in the examination room, this is equivalent to making sufficient preparations for the future, maybe three or five years later, in case 4.9 With the widespread deployment of the G band, customers no longer need to consider product upgrades.