dojammer's blog

Recently, we have often received inquiries from some customers who want to buy a suitable wireless signal jammer from us. The purpose is also very clear, which is to block surveillance cameras. Usually when we encounter such a demand, we will directly refuse it. . So the question is, can’t the wireless signal jammer we produce block surveillance cameras?
Here, as a professional manufacturer of wireless signal jammers, we first make a statement: If you want to use the wireless signal jammers produced by our company for illegal activities or non-faithful purposes, we are firmly opposed and refuse to sell them. Therefore, when some customers consult us about wireless signal jammers and ask questions about some actual usage purposes and functional requirements, the customer's responses are obviously slow or deliberately concealing, and we will quickly become vigilant about this.

Customers in the purchase of cell phone signal jammer equipment, generally as long as no special instructions, the manufacturer's default factory band, is not included in the GPS positioning signal shielding module, but if the customer in the order of shielding equipment, very clearly put forward the requirements: the need to shield all the mobile phone signal lamps at the same time, can be able to shield the GPS positioning signals, then the manufacturer can be targeted to GPS frequency band shielding module to be added to the equipment. Shielding module to add to the equipment.

Why is there no GPS band in the default configuration of the low-power mobile phone signal jammer instrument? There are three main reasons: the first reason is that the low-power mobile phone signal jammer equipment is almost always used in fixed indoor environments, indoor environments in the GPS signal itself is very weak, or even there is no GPS signal, GPS signal shielding function will not come in handy. The second reason is that the primary purpose of the low-power type of mobile phone signal shielding instrument is to shield mobile phone signals, in order to reflect as much as possible for the shielding performance of mobile phone signals, manufacturers preferred solution is: the number of effective signal shielding module, as much as possible to the allocation of mobile phone signal band. The third reason is that the mobile phone signal shielding instrument manufacturers in order to control production costs, if a function is not a customer requirement must have, that less installed a module, after all, can reduce some production costs, you can enhance some of the mobile phone signal shielding instrument selling price advantage.

However, it should be reminded that: today's GPS positioning signals, it is only a general term, does not specifically refer to the United States of America's GPS navigation satellite signals, in fact, should at least include China's Beidou, Europe's Galileo, Russia's GLONASS, etc., these multiple countries and types of satellite navigation and positioning systems, in the increase of GPS signal shielding module, should be all can be effectively covered.

In the procurement of portable cell phone signal jammer, some customers are very enthusiastic to put the shielding equipment into the actual task very quickly, but also sometimes feedback back some information: the shielding signal coverage is a little on the small side. And after replacing the different working environment, feel the shielding distance of the shielding signal, some scenes will be larger, while some scenes are smaller, ask us what's going on?

First of all, the portable signal jammer itself is a fixed transmitter power. That is, the strength of the shielding signal it emits is relatively stable, will not be big or small, different environments, there will be several factors affecting the coverage of the shielding signal, such as: the proximity of the base station, the error of the building or wall obstacles, etc., which will have a direct impact on the shielding signal of the effective shielding distance.

Secondly, the placement of the portable cell phone signal jammer is also more critical. Because of its main chassis height of about 70cm, its antenna is screwed directly to the main chassis, that is to say, if the portable cell phone signal shield is placed directly on the ground, then its transmitter antenna height from the ground is generally not more than 1 meter. To enhance the coverage of the shielding signal, the simplest way is to increase the height of the antenna from the ground, when the height of the antenna increases, the effective shielding distance of the shielding signal will be greatly increased.

So, what is the height of increasing the antenna? We suggest that the user should first observe the terrain and terrain at the scene, and try to choose the position of the highest point to place the portable cell phone signal shield. Or use some desktop, steps or buildings, etc., try to use the portable cell phone signal shield to increase the height by using these positions.

There is another way: you can choose our company's antenna bracket, the portable cell phone signal shielding antenna and the host through the 3-meter feeder cable for connection, the antenna is mounted on the bracket, our customized antenna bracket, you can support the antenna up to a height of 3 meters.

There are many kinds of cell phone signal jammers on the market today, and most of them are realized by wide-band white noise power suppression. During its use, there are many types of shielding devices that more or less interfere with the surrounding mobile phone base stations. This kind of interference is mainly aimed at the interference of the uplink signal of the base station, and the method to solve this interference problem is actually not difficult. It only needs to add the time division duplex synchronization technology of the signal base station to the interference signal of some specific frequency bands. Then, in which frequency bands does the mobile phone signal shielding system need to add base station time division duplex synchronization technology to avoid interfering with the base station?

The frequency band targeted by the base station time division duplex synchronization technology mentioned here refers to the mobile phone frequency band using time division duplex, and the other frequency bands adopt frequency division duplex mode, which strictly distinguishes the range of uplink frequency band and downlink frequency band. Taking the frequency band of GSM900 as an example, the uplink frequency range of GSM900 is 885-915MHz. In this frequency range, only data transmission of uplink signals is performed. The downlink frequency range of GSM900 is 930-960MHz. In this frequency range, only the data transmission of the downlink signal is carried out. The two frequency bands do not overlap each other, and data communication is carried out in its own way. Let's take the time division duplex frequency band as an example, such as the TD-SCDMA frequency band, the frequency range is 2010-2025MHz, and the overall bandwidth is 15MHz, but because of the time division duplex technology, their uplink data and downlink data are all in this 15MHz The transmission is performed in the bandwidth, but it is divided by time, that is, it is dedicated to uplink data in a period of time, and dedicated to downlink data in the next period of time.

We use base station time-division duplex synchronization technology for signal jammers, that is, time synchronization for time-division duplex frequency bands, so that the signal shielding module for time-division duplex can process downlink at the mobile phone base station after clock synchronization When the signal is transmitted, an interference signal is emitted. On the contrary, when the base station processes uplink data, the corresponding frequency band of the mobile phone signal shielding system stops working.

We sort out and count the time division duplex frequency bands used by various operators at present. Now there are mainly 5 frequency bands using time division duplex technology, namely China Mobile's 1885-1915MHz, 2010-2025 MHz G, 2515- 2675 MHz, 2300MHz for indoor micro base station signal amplification, and 3.5GHz for China Telecom and China Unicom.

Based on the above analysis, we only need to install the time division duplex synchronization technology of the signal base station in all the five frequency bands in the mobile phone signal shielding system, and then we can completely avoid interfering with the uplink signal of the mobile phone base station.

In order to improve user perception and satisfaction, the mobile company has taken various measures to solve the problem of radio interference: one is to set up a quick complaint channel and set up a dedicated complaint hotline to ensure the problems are reported to users will be solved in the first time. The second is to increase publicity and education, and create posters and individual pages with complaints about radio interference and related requirements for investigation and handling, and post them in residential areas and group units to remind users that the cessation of Using security camera wifi jammers and repeaters without permission is a crime and may violate criminal law. , If the general public often encounter abnormal mobile phone signal or WIFI signal, please report to the operator in time. The third is to coordinate with multiple parties and establish a smooth coordination mechanism with the Radio Management Committee and the Public Security Bureau to ensure that operators, non-delegated committees and public security bureaus conduct investigations and deal with radio transmissions affecting the disturb citizens. normal life and order, and crack down on them. Jammer Able to block 5 frequency bands simultaneously, this powerful remote control jammer is popular now.

While there is no cell phone jammer to block the data signal, it is very likely that other safer and more environmentally friendly inspection methods are being used. Therefore, it is better to express these ideas more appropriately. Before decoding cell phone jammer data signal, you need to know its basic principle: jammer security camera According to the shielding style, it is divided into omnidirectional and fixed type. The omnidirectional type is an olive type, and the fixed type is an olive type. Sector type, i.e. omnidirectional cell phone jammers have a larger shielding area than fixed type cell phone jammers.

Wireless walkie-talkie signal coverage system

This design is designed according to the full range of indoor and outdoor coverage of the building. Specifically, it includes: the upper floors of the building, the air defense layer, the outdoor park and the beach area; covering public areas, guest room floors, elevator halls, stairwells, machine rooms, etc. If necessary , our company will organize personnel to carry instruments to carry out field tests of this project to ensure that there are no blind spots in the coverage area.

Combined with the digital intercom communication system, a new generation of digital intelligent patrol dispatching management system is tailored for property security users. The new generation of patrol system combines wireless communication technology with the traditional patrol system to realize digital intercom and patrol Great combination of two into one. wifi jammer, The patrol information is sent back to the patrol dispatching station in real time through the short data transmission function of the digital intercom system, so as to truly realize the real-time online monitoring of the patrol personnel. At the same time, the digital voice provides users with more Clear sound quality more effectively guarantees dispatching and commanding.

(1) Adopt the digital wireless intercom system base station inter-frequency transfer technology to expand the communication range of the intercom

When the communication between the walkie-talkies cannot be realized due to the long distance or the obstruction of buildings, the base station can transfer the signals of the walkie-talkies in different frequencies, and then send the signals through the distribution system, thereby expanding the communication distance between the walkie-talkies;

(2) The underground parking garage of the building is equipped with a distribution system to solve the problem of signal shielding in the basement. The distribution system consists of an indoor omnidirectional antenna, a flat-panel directional antenna, a coupling distributor, a power distributor, a trunk amplifier, a connector, a low-loss radio frequency cable, and a leakage cable. gsm jammer, Combined with national electromagnetic radiation standards and building structure, antennas are distributed in every corner of the basement, and then connected to the center of the base station through cables, so that wireless signals can be received or transmitted through the antenna, so as to reach the entire basement area of the building The wireless signal coverage; the outdoor area of the building adopts a low-power outdoor omnidirectional antenna, and the output power is adjusted through calculation to ensure that the entire outdoor area of the building is covered, and at the same time there will be no signal leakage out of the peripheral area of the building.

(3) Shared system to increase communication capacity

The shared system is composed of a combiner, a splitter and a signal tandem controller, which can integrate up to eight digital base station signals into the same distribution system for reception or transmission, saving materials, repeated wiring, debugging and other unnecessary investment, thereby reducing costs;

(5) Wireless intercom patrol system

Under this system, real-time patrol management can be realized by adding patrol dispatch management center, patrol software, information button, and patrol walkie-talkie.

Combined with the actual communication application requirements of the building, a variety of wireless communication coverage schemes in the building have been formulated. The following principles are adopted for the construction of the scheme:

1. Sex principle:

The system as a whole must have a certain level from resource allocation (including hardware equipment, technical means) to functional use.

2. Reliability principle:

The reliability of various resources of the system, including hardware equipment, etc. must have a certain high standard, work stably, and be easy to maintain; in the event of a hardware failure, there must be a reliable backup means.

3. The principle of technological maturity:

The system should adopt mature technology as far as possible, so that it can be put into practical use after completion and achieve the designed use effect.

4. Scalability principle:

The overall structure of the system is reasonable, the design capacity is moderate, and it must be scalable. On the premise of protecting the original investment, resource expansion can be increased, including the increase of communication coverage and distance.

Nowadays, mobile phones have become an indispensable part of people. Almost everyone has a mobile phone. The birth of mobile phones has brought great convenience to our lives and created many opportunities for people to communicate. But everything will have good and bad sides, and many problems will appear under the premise of bringing convenience to people. For example, cell phones are not allowed in schools, and cell phones are supervised in detention centers and the military. Special venues such as examination rooms and prison cells will use full-band signal jammers or devices that shield mobile phone signals, so that communication with outsiders can be effectively avoided.

There are many important things in our life, and some things will always affect our whole life. For example, the college entrance examination that each of us has experienced is one of the most important things in life. In order to prevent unfair and just situations such as cheating during the college entrance examination, now every exam room will install a cell phone signal jammer to interfere Block mobile phone data signals to prevent cheating in the examination room.

In some special areas, the control of mobile phones is relatively strict, such as prisons, police stations and other special control areas. The full-band signal jammers installed in these areas are the last natural barrier to prevent criminals and suspects from contacting the outside world. Behavior for social stability.

There are also some very special areas, such as military and state secret places, and the core of test papers, which assemble full-band jammers, which can prevent leakage and loss of key materials. When important meetings of government agencies and enterprises are held, mobile phones are used casually, making the meeting unable to proceed normally. However, in order to concentrate the attention of the participants, it is necessary to be equipped with a full-band jammer.

In addition to the places mentioned above, mobile phones are prohibited at gas stations. We all know that talking on the phone at a gas station can also cause fires and explosions, but there are also people who use mobile phones regardless of the danger. Therefore, it is necessary to install a full-band jammer at the gas station.

GSM connections in Moldova are deliberately interrupted by the de facto independent and internationally unrecognized region of Transnistria (de facto).

Mobile phone customers and network operators in Moldova (Moldova, approx. 4.3 million inhabitants) have big problems with GSM whining. GSM connections in Moldova are deliberately interrupted by the de facto independent and internationally unrecognized region of Transnistria (de facto). gsm jammer, In early September, the transmission power of jammers active for three years increased threefold, which significantly worsened the situation in Moldova. GSM network operators suffer heavy financial losses and communication is made more difficult.

In addition to technical measures, grid operator Moldcell has now also had to give in to tariffs in order to appease obviously upset customers. By realigning existing transmitters as well as 15 new base stations and 36 new antennas, the rate of dropped calls was officially reduced from 6.8% to 4.9%, in Chisinau, the capital, particularly affected by the misdeeds of radio, at 3.9%. This value is still very high compared to Western European GSM networks, as it means that every 20th to 25th call drops.

In mid-September, Moldcell had explained to its customers the cause of the problems and countermeasures by sending a message to all TV programs. However, public understanding is likely to be limited, which is why price reductions were now necessary at least until the end of the year. Some base fees have been reduced to zero, while other rates allow unused free minutes to be rolled over to the next month. Vouchers for prepaid customers now offer 45 minutes instead of 15 minutes of talktime for the same price. At the same time, the provider emphasizes that the problems are not to blame. gps jammer

While the Communist Party rules with an absolute majority in the Romanian part of Moldova (west of the Dniester), the narrow strip of land between the Dniester and the Ukrainians is mainly populated by Ukrainians and Russians. They have aspired to independence for years and in fact have control of the region. There is also its own mobile network, which works with the CDMA process in the 800 MHz band and therefore is not affected by the GSM jammer in the 900 MHz band. Besides the political background of constant disruption, pecuniary crime in the form of extortion from GSM network operators cannot be ruled out.

Cell phone signal jammers are used more and more. In addition to the general test site, they are also used frequently in competition sites from all walks of life. The 2022 Huawei Mobile Cup China Go League One, which is currently being held in Chengdu, has adopted a number of anti-cheating measures, and installed a mobile phone signal jammer in the bathroom for the first time to cut off the possibility of AI cheating from the source.

According to the relevant regulations of the Go competition, players must take out their mobile phones before entering the arena and hand them over to the staff for safekeeping. This year's Siege League matches are played in the same hotel as the chess players' land, and chess players are required to leave their mobile phones in the room as required and are not allowed to bring them into the arena.

Like most Go tournaments, this year Siege installed a security gate at the entrance of the arena. Players must go through security checks before entering the arena. Once the alarm sounds, the staff will check it by hand, and the players can enter the arena only after confirming that it is correct.

In addition to conventional security measures such as security gates and surveillance cameras, there are also full-time referees on site to supervise and patrol the Siege League. During the game, all chess players are not allowed to leave the arena area, and are limited to activities in the arena and toilet area. Once a chess player is found to return to the room privately during the game, he will be sentenced to lose.

In addition to strict requirements for chess players, team leaders, coaches, media and other relevant personnel must leave the arena 30 minutes after the start of the game. Even for the rapid chess match that started at 13:00 that day, relevant personnel were no longer allowed to enter the arena.

Unlike most sports, a game of Go usually takes five or six hours to play. During this period, players will drink tea and coffee to refresh themselves, and it is inevitable to go to the bathroom several times. In the AI era, there have been chess players cheating in the bathroom. However, in view of the violation of personal freedom and the cost of installing signal jammers, few events have adopted relevant anti-AI cheating measures in the bathroom before.

For this year's Siege League, the organizer Chengdu Chess Academy installed mobile phone signal jammers in the bathroom of the arena. After entering the bathroom, the mobile phone signal disappears immediately, and you cannot access the Internet or make calls, cutting off the possibility of AI cheating from the source. According to relevant staff, mobile phone signal jammers will become one of the conventional means of preventing cheating in Go games in the future, so as to avoid cheating as much as possible.

The advancement of science and technology has added great convenience to everyone's daily life, especially in the past two years, communication technology has advanced rapidly, and many data wifi jammer manufacturers are updating their equipment for the development of the times. In order to be able to integrate into the requirements of the new business model, high-tech can improve the innovative technology prevention and control business capabilities of the detention center, improve the innovative technology management level of the detention center, and promote the construction of intelligent infrastructure projects. Systematic detention centers, promote the harmonious and stable development of detention centers, and continuously improve the level of intelligent systems in detention centers. Standardize and efficiently manipulate and prevent detention center signals, and eliminate potential safety hazards caused by illegal use of mobile phones.

Problem 1: Interference can be avoided by using directional antennas

1. The azimuth angle of the directional antenna has a certain emission point signal, which is only much lower than the main lobe, and is not completely fixed;

2. The vertical surface of the building will still interfere with the expansion of the opening;

3. The output power drift of the network server seriously threatens the mobile base station, causing the expansion of open interference

4. TD 24-hour shielding interference must exist.

Question 2: The bigger the power, the better

1. The output power of the network server is not accurately derived, the output power drifts, the server bandwidth is too wide, power consumption, and mobile base station interference;

2. The shielding efficiency of the simple frequency offset power suppression method is not high, and the radiation is large;

3. The power is too high, exaggerated, publicized, and the standard power lacks practical significance;

4. Power-based, technology-based. It is better to find good methods and techniques than to fight hard;

Question 3: The radiation of high-power mechanical equipment is large, and the radiation of low-power mechanical equipment is small

1. The function of high-power TV antenna, the effect distance is long, the shielding range is large, the shielding signal is uniform, and the radiation is particularly small;

2. Low-power mechanical equipment uses multiple external antennas without long-distance shielding, centralized and precise positioning, or when 5 external antennas work together, the radiation power exceeds 10 microwatts/cubic decimeter, and the short-distance radiation has always exceeded the standard.