dojammer's blog

Recently, a key device that has been frequently active in major examination halls, I believe many people should know the real role of this device. It is a key device that has been vigorously promoted in school exams of all sizes, which can effectively prevent and prevent candidates from cheating. That is today's protagonist: cell phone signal jammer.

Now there are less than 100 days left before the college entrance examination. All candidates taking the college entrance examination are concentrating on preparing for the college entrance examination and striving to achieve good results in the college entrance examination. At the same time, many schools are looking for a batch of more high-performance cell phone signal jammers to ensure a stable order in the examination hall, so that those who use illegal means to cheat have nowhere to hide, thereby improving the fairness of the college entrance examination to each candidate.

But what many people don't know is that there is such a device, which may have a serious impact on the effect of the cell phone signal jammer, that is, the shielding range, which is a problem that all college entrance examination examination halls in the school need to consider. What is this device? It is the operator's base station, commonly known as a signal tower, because if there is a base station near the examination hall, it will affect the shielding effect of the mobile phone signal jammer. Of course, this refers to the signal strength of the signal transmitted by the base station to the examination room within 500 meters near the examination room, so the shielding range of the mobile phone signal jammer will be smaller. If the base station is 500 meters away from the examination room, the impact on the mobile phone signal jammer is very small. As for why it causes an impact, this is because when the base station itself transmits signals to the surrounding area, it will carry a strong electromagnetic signal, and the electromagnetic signal emitted by the base station will decrease accordingly as the distance increases. The strength of the electromagnetic signal field is one of the most important factors affecting the shielding effect of the cell phone signal jammer.

Therefore, in terms of the examination room, before purchasing a cell phone signal jammer, it is better to actually test it first to determine the actual shielding range of the jammer, and then decide how manycell phone signal jammers are needed based on the actual test data. This is very important, otherwise some places will not be shielded. However, regardless of whether the cell phone signal jammer will be affected, a more superior and more professional cell phone signal jammer is a must.

Before installing the conference room signal jammer, it is necessary to test the shielding effect.

When it comes to conference rooms, they are generally divided into small conference rooms, medium conference rooms, and large conference rooms according to the size of the area. Before installing the conference room signal jammer, the test methods for these three types of conference room signal jammers are also different. The environments of these three types of conference rooms are also completely different.

The area of ​​the small conference room is relatively small, the environment is relatively simple, and the requirements are not very high. When testing, you only need to place the conference room signal jammer on the table against the wall, and then test whether the mobile phone is blocked at the farthest section from the conference room signal jammer.

Medium-sized conference rooms are generally located on higher floors. The higher the floor, the stronger the signal from the base station to the conference room. In addition, there are basically indoor signal amplification systems in buildings. It is necessary to test the signal strength of various frequency bands separately, and then adjust the conference room signal jammer, or increase the power of some frequency bands to meet the mobile phone signal shielding requirements of medium-sized conference rooms. High-power modules can be used to cover the frequency bands with stronger signals separately, and then use low-power conference room signal jammers to shield the relatively weak mobile phone signals.

Large conference rooms can also be called venues, which refer to places that can accommodate hundreds or even thousands of people for meetings, such as the Great Hall of the People. The conference room signal jammers used in such large venues are not ordinary low-power signal jammers. A high-power conference room signal jammer is required to meet the purpose of covering the entire venue's cell phone signals, and according to the signal strength of all mobile phone signal frequency bands within the tested venue, the signal strength of the transmitting signal source must be adjusted to achieve the purpose of reducing the mobile phone signal in the venue, so that the conference room signal jammer can play the greatest role.

The use of a cell phone signal jammer should not be at the expense of public mobile communications.

Among individuals or units that use cell phone signal jammers, school exams use cell phone signal jammers to prevent cheating in exams, and conference venues use cell phone signal jammers to keep the venue quiet or keep conference information confidential. These are all for good intentions and purposes. But there are also those who use them for their own selfish interests. For example, a household owner who operates a public telephone may use a mobile phone signal jammer to interfere with the mobile communication base station near his business location, so that people who do business near the public telephone he operates cannot use their mobile phones, but use public telephones to make calls instead, thereby increasing their own economic income. In addition, mobile communication operators may also usecell phone signal jammers to harm each other's interests and gain an advantage in some local competition in the same industry. In addition, cell phone signal jammers can also be easily added with software, becoming a veritable eavesdropping device.

The above are the purposes for people to use cell phone signal jammers, but no matter what the purpose is, it should not be at the expense of public mobile communications. In fact, according to research, it is possible to install a cell phone signal jammer without affecting the normal use of public mobile communications.

There are three reasons why cell phone signal jammers disrupt mobile communication base station signals:

First, the user of the cell phone signal jammer completely ignores the communication needs of outsiders and acts on the wrong object. It should limit the mobile phone communication of a small number of people (such as candidates), but expands the object to the surrounding people.

Second, improper use methods. Due to improper installation of the cell phone signal jammer or excessive setting of its transmission power, it should be controlled within a small range but is not well controlled.

Third, the cell phone signal jammer purchased by the user does not meet the radio equipment approval standards, the power exceeds the standard, or it is a low-quality and unqualified product.

After finding the cause, in order to overcome its impact on mobile communication signals, it is actually very simple: first, use qualified products produced by regular manufacturers, second, choose the installation location and direction of action, and third, set the appropriate transmission power to limit its transmission signal to a small closed range. As long as the above three points are achieved, its impact on nearby mobile communication base stations can be minimized, and it will not affect the normal calls of the surrounding people.

In recent years, in various national examinations, cases of cheating with mobile phones have occurred from time to time, seriously affecting the fairness and justice of the examinations. For this reason, the state stipulates that cell phone jammers must be equipped during important examinations to create a fair examination atmosphere for candidates. So, after turning on the cell phone jammer, why do some mobile phones still show signals?

1. The cell phone shows that there is a signal, and when the mobile phone makes a call, if the mobile phone can connect the call normally, and the call quality is relatively high and not affected, this situation indicates that the cell phone jammer area has not achieved effective shielding. If the mobile phone is close to the cell phone jammer, there is no signal, which means that there is a base station or signal amplification at your location, and then it means that the cell phone jammer you are currently using cannot meet your on-site shielding requirements. You can install more high-power cell phone jammers.

2. The mobile phone shows that there is a signal, but the call quality of the mobile phone is relatively poor. If this is the case, it means that the shielding effect of the cell phone jammer on the mobile phone is in a critical state, with a shielding effect, but the shielding range is unstable. This situation may be that the signal strength from the base station to the site of use fluctuates, and this situation may also occur with some mobile phones with strong anti-interference.

3. The mobile phone shows that there is a signal, but in fact the signal is false. The mobile phone cannot make calls normally, nor can it access the Internet. When making a call, the mobile phone will suddenly show no signal or limit the service. At this time, it can be determined that the signal displayed on the mobile phone is a false signal, but in fact the mobile phone is blocked.

The size of the shielding range of the cell phone jammer depends on the strength of the cell phone signal at the location of the user unit. Where the mobile phone signal is strong, the shielding distance of the cell phone jammer will be shortened. Where the mobile phone signal is weak, the shielding distance of the cell phone jammer will be far.

In general, it is not recommended to use a high-power cell phone signal jammer to shield the entire teaching building. This is because it cannot be ensured that the entire teaching building can be completely shielded by using a high-power mobile phone signal jammer. Even if a high-power cell phone signal jammer is used to shield the entire teaching building, there will be some areas where mobile phone signals cannot be shielded.

However, in some specific cases, using a high-power cell phone signal jammer to shield the entire teaching building can also achieve a shielding effect. For example, during the high school entrance examination and the college entrance examination, the use of a high-power mobile phone signal jammer to shield the entire examination room during the short three days of the high school entrance examination and the college entrance examination can completely achieve a shielding effect. This is because, during the high school entrance examination and the college entrance examination, the relevant departments of the government at all levels across the country must take joint action to ensure that these candidates can successfully complete the examination, including public security, transportation, non-management committee, education bureau, examination institute, communication operators and other relevant departments or organizations, all of which must perform their duties to ensure that the high school entrance examination can be successfully concluded.

Among them, the public security is responsible for maintaining order, the traffic is responsible for directing traffic, the radio management committee is responsible for purifying the radio signal environment around the examination room, and the communication operator is responsible for reducing the signal strength of all base stations within a few kilometers around the examination room or choosing to directly shut down the base station. The size of the shielding range of the cell phone signal jammer, or the quality of the shielding effect, depends on the strength of the mobile phone signal in the examination room.

The communication operator reduces or shuts down the base station signal within a few kilometers around the examination room in order to reduce the signal strength in the examination room to ensure the shielding effect of the mobile phone signal jammer, thereby purifying the radio environment in the examination room and preventing some unscrupulous candidates from using radio to cheat or transmit answers. I believe everyone will also notice that the operator will push text messages during the college entrance examination to inform that the cell phone signal jammer is used in the examination room, and the mobile phone will be disconnected from the network at that time.

We have to go through many examinations, including the junior high school entrance examination, the college entrance examination, the postgraduate examination, the CET-4 and CET-6 examinations, various qualification certificate examinations, and the annual civil service examination, etc. In the examination room, the most common examination auxiliary equipment is the cell phone signal jammer to prevent cheating.

Nowadays, the cell phone signal jammer has basically achieved modularization, that is, different frequency bands use different modules. Through the rapid replacement of modules, it can achieve the advantages of rapid repair or rapid increase of frequency bands. Adding different frequency band modules on the basis of the original cell phone signal jammer is still a headache for many manufacturers, because at the beginning of the design, they were designed according to the standard mobile phone frequency band, lacking different usage scenarios and the functions added by the interference modules of different frequency bands.

The cell phone signal jammer produced by Nanjing Bokang Electromechanical Technology Co., Ltd. has been fully considered in the design. The requirements of adding modules of different frequency bands in the later stage can be easily realized by superimposing the radiator, which can easily expand the original 12-channel output to 24-channel output. The fixed holes required for superimposing the radiator are reserved, so that even if more frequency bands of cell phone signal jammers need to be added in the later stage, there is no need to worry about insufficient space for the radiator. And it can be expanded to up to 24 interference frequency modules to achieve signal interference of more frequencies, or to achieve the same scene through the refinement of the frequency, and to expand the ability of shielding effect.

Before the cell phone signal jammer is officially activated, the shielding effect of the cell phone signal jammer must be tested first, so that the installation location and number of cell phone signal jammers can be selected.

First, preset the installation location of the cell phone signal jammer, and place the cell phone signal jammer on the desktop, generally placed in the front and back corners of the site of use, turn on the power and turn on the switch, and then the shielding effect test can be carried out.

Before preparing for the test, prepare three mobile phones of different operators, and place the mobile phones at the opposite corners of the site of use, which is also the farthest position from the signal jammer on the machine. Then let the mobile phone stand for about 2 minutes. During this period, please do not perform any operations on these three mobile phones, and then check whether the mobile phone signal on the mobile phone screen is blocked. If it shows no mobile phone signal, then the mobile phone of this operator is blocked. If the mobile phone shows a signal, you can try to call the operator's customer service hotline, or use the mobile phone network for data Internet access. If you can make a call or data Internet access, then you need to move the mobile phone to a position close to the mobile phone signal jammer, and go back and forth until the mobile phone is completely blocked, and the mobile phone cannot make a call or data Internet access. This is used to determine the shielding range of the mobile phone signal jammer, and the number of mobile phone signal jammers to be used is determined by this shielding range.

If the cell phone signal at the site of use is strong, and the low-power cell phone signal jammer cannot completely shield the entire site of use, you can determine the signal frequency band that the mobile phone signal jammer cannot shield, and then use the high-power shielding module to perform targeted interference on this frequency band based on the tested frequency band. First, you need to use an Android phone to download the Cellular-Z mobile phone APP, and then open this mobile phone APP on the premise of turning on the mobile phone signal jammer, and then take a screenshot and send it to the supplier technician of the cell phone signal jammer, and the manufacturer will determine the cell phone signal frequency band that the mobile phone signal jammer cannot shield. Finally, by using a high-power shielding module to cover the frequency band with a strong signal, the cell phone signal at the place of use can be shielded.

We have to go through many examinations, including the junior high school entrance examination, the college entrance examination, the postgraduate examination, the CET-4 and CET-6 examinations, various qualification certificate examinations, and the annual civil service examination, etc. In the examination room, the most common examination room auxiliary equipment is the cell phone signal jammer to prevent cheating.

Nowadays, the cell phone signal jammer has basically achieved modularization, that is, different frequency bands use different modules. Through the rapid replacement of modules, it can achieve the advantages of rapid repair or rapid increase of frequency bands. Adding different frequency band modules on the basis of the original cell phone signal jammer is still a headache for many manufacturers, because at the beginning of the design, they were designed according to the standard mobile phone frequency band, lacking different usage scenarios and the functions added by the interference modules of different frequency bands.

The cell phone signal jammer produced by Nanjing Bokang Electromechanical Technology Co., Ltd. has been fully considered in the design. The requirements of adding modules of different frequency bands in the later stage can be easily realized by superimposing the radiator, which can easily expand the original 12-channel output to 24-channel output. The fixed holes required for superimposing the radiator are reserved, so that even if more frequency bands of cell phone signal jammers need to be added in the later stage, there is no need to worry about insufficient space for the radiator. And it can be expanded to up to 24 interference frequency modules to achieve signal interference of more frequencies, or to achieve the same scene through the refinement of the frequency, and to expand the ability of shielding effect.

To know whether the cell phone signal jammer will interfere with the ZigBee signal, you must first understand what the ZigBee signal is. Zigbee technology is a wireless communication technology used in short distances and low rates. Zigbee was previously known as "HomeRF Lite" and "FireFly" technology, and is collectively referred to as Zigbee technology.

It is mainly used for data transmission between various electronic devices with short distances, low power consumption and low transmission rates, as well as typical applications with periodic data, intermittent data and low response time data transmission.

ZigBee is a wireless connection that can operate on three frequency bands: 2.4GHz (popular worldwide), 868MHz (popular in Europe) and 915 MHz (popular in the United States).

Based on the signal frequency used by ZigBee, it can be concluded that the cell phone signal jammer will not interfere with the ZigBee signal. The signal frequency band used by the cell phone signal jammer is closest to the frequency band used by ZigBee at 868MHz (popular in Europe) and 915 MHz, but there is no frequency band that overlaps with the output signal of the mobile phone signal jammer. Everyone knows that the signal emitted by the cell phone signal jammer is in the same frequency band as the mobile phone signal. The lowest frequency band is 870-880 for CDMA, and the GSM frequency band is 930-960. Now the 5G signal frequency of radio and television is 700MHz, which is not repeated with the ZigBee signal, so the signal emitted by the cell phone signal jammer will not interfere with the ZigBee signal.

In prisons, detention centers and other places of supervision, mobile phones and other communication tools are prohibited from being brought into the supervision area. Once a mobile phone is brought into the supervision area by some lawless elements through unknown means and put into use, it will bring great harm to the management, safety and development of the supervision area. Because of this, it is very necessary to install a cell phone signal shielding system in prisons and other places of supervision.

Compared with ordinary cell phone blockers, the cell phone shielding system has relatively outstanding characteristics, which are mainly manifested in the following aspects.

1. The cell phone signal shielding system can be centrally controlled and managed by software.

The entire cell phone shielding system is controlled and managed by a set of software. The management personnel can see the shielding status in the prison area at a glance through the unit structure diagram (equivalent to the unit electronic map) on the main control software. This brings greater convenience to the management of mobile phone signal blockers installed in the supervision place and saves a lot of management time.

2. The cell phone signal shielding system can freely group the cell phone blockers, which can be fully opened or fully closed, and can be switched in groups (by building, by area), and can be switched point to point. In this way, the equipment manager can sit at the computer, open the software, and realize the remote switch of all mobile phone signal blockers, and can also directly see whether the mobile phone blocker is turned on on the software.

3. The manager can manually operate the cell phone blocking system or set it to automatically query the working status of each mobile phone blocker. For mobile phone signal blockers that are faulty or damaged, the mobile phone blocking system can be found immediately, greatly reducing the daily inspection time and speed of managers.

4. The manager can adjust the transmission power of each module of each mobile phone blocker by operating the cell phone signal blocking system, that is, the shielding range of the cell phone blocker can be adjusted, and the shielding range of the mobile phone blocker installed around the prison wall can be controlled as much as possible within the wall, which will not affect the normal communication of the people outside the prison area. Thereby avoiding unnecessary trouble.