月別アーカイブ: 2024年6月

Wang Fu, a partner at Beijing Xinbang Law Firm, said that Article 18 of my country’s Prison Law stipulates that “when a criminal is taken into prison, his person and the items he carries shall be strictly checked. Non-essential items shall be kept by the prison or returned to his family with the consent of the criminal, and contraband items shall be confiscated.” Contraband items are items that are strictly prohibited for criminals serving sentences in prisons, such as cash, drugs, and mobile phones. If they are not prohibited, they will undoubtedly interfere with and hinder prison management and the order of criminal reform. According to the law, the external communication of serving criminals should be regulated, so mobile phones are naturally contraband items.

An insider said that it is difficult to manage high-IQ criminals serving sentences in prisons. Once a mobile phone is in hand, the risk of using it for illegal crimes increases sharply. In fact, from legislation to local judicial administrative departments, prison administration bureaus, and then to prisons, there are strict systems for prison order and contraband management. If a prisoner in prison secretly keeps or uses a mobile phone, it is a serious violation of discipline, which is higher than a general violation of discipline. Once caught, he will not only be put in solitary confinement, but also directly affect his sentence reduction. The punishment is very severe.  cell phone jammer

As early as 2006, the Ministry of Justice promulgated the “Several Provisions on Strengthening Prison Security and Stability Work”, which clearly stipulated that “those who secretly keep or use mobile phones, or secretly keep or take drugs, will be punished with solitary confinement. From the date of release from solitary confinement, they will not be allowed to apply for sentence reduction or parole within two years (except for those who have made major meritorious contributions).”

In November 2009, the Ministry of Justice issued the “Several Provisions on Strengthening Prison Security Management Work”, proposing that “prisons should install mobile phone signal shielding devices” and requiring strict implementation of the contraband inventory system to prevent criminals from possessing contraband such as mobile phones, drugs, and cash. In terms of strict police management, it is required that “a special counter for storing police mobile phones should be set up outside the prison gate, and the police officers who bring mobile phones into the prison should have their police ranks revoked.”

However, the 20 cases searched by The Paper show that most of the mobile phone disciplinary cases in prisons show the characteristics of “mobile phone rent-seeking”. Many prison guards concealed or downgraded the private possession and use of mobile phones by serving prisoners due to receiving benefits, and also provided assistance to the prisoners to apply for commutation of sentence as usual; some provided mobile phones for criminals to make calls, and some even recharged the mobile phones of criminals.

How did the mobile phone break through the layers of defense and be brought into the prison and into the hands of serving prisoners? Among the above 20 cases, except for two cases that clearly identified prison guards smuggling mobile phones into the prison for serving prisoners, in the remaining cases, there was no mention of how the mobile phone was brought into the prison and who brought it into the prison, and some showed that it was not clear.

On January 29, 2015, in response to the internal management problems exposed by the Nehe Prison case, the Ministry of Justice deployed a nationwide prison rectification campaign, and deployed special clearance of contraband and illegal items and special education activities such as “strict discipline and strict performance of duties” in prisons and drug rehabilitation centers across the country. The focus was on confiscating contraband such as mobile phones, cash, and drugs.

On March 30 of that year, the Ministry of Justice issued the “Several Provisions on Effectively Strengthening the Management of Contraband Items in Prisons and Compulsory Drug Rehabilitation Centers”, and imposed “increased penalties” on criminals who privately kept contraband. It clearly stipulates that “criminals who privately keep and use contraband items are in violation of the provisions of the Criminal Law and the Prison Law, and shall not apply for commutation of sentence or parole within three years.”

Ontario is the only province in Canada that actively bans the use of cell phones in the classroom. Similar proposals have been defeated in Quebec, Nova Scotia and British Columbia.

But some Canadian schools and districts have taken it upon themselves to ban students from using cell phones in class.cell phone jammer

At St. Thomas High School in Montreal, Que., and Elk Island Public Schools in Alta., school administrators are enforcing cellphone bans, requiring students to lock their phones at the start of the day or turn them off during class. cell phone.

According to CBC, school counselor Tulani Pierce said that Chatelech High School, located on the Sunshine Coast of British Columbia, banned the use of mobile phones six months ago, and the results have been very significant.

“We’re seeing improved mental health, reduced bullying, increased classroom engagement and increased social interaction,” Pierce said. “Kids are playing again instead of on their phones, and we’re seeing improvements in their academic performance.”
Expert: Mobile phones affect students’ mental health
Sachin Maharaj, assistant professor of educational leadership, policy and program evaluation at the University of Ottawa, said mobile phones have a big impact on students’ mental health.

Maharaj believes that schools not only teach content but also “habits of mind,” including the ability to think deeply, focus for long periods of time, and listen attentively and empathetically to others.

“When students are exposed to constant distractions from cell phones, their ability to do these things is reduced.” At the University of Ottawa, Maharaj said, the mere presence of cell phones in classrooms can be distracting for students.

Students worry about what they will miss if they don’t check their phones. Maharaj said cellphone bans for students would be particularly difficult to enforce, given that adults are equally dependent on their phones.

Maharaj believes that a successful mobile phone ban must be all-encompassing and should apply to the entire school and be an established set of rules that does not differentiate between classrooms.

“As a society, we need to carve out at least some spaces where teenagers can go away from all the distractions, and I think school should be one of those spaces,” Maharaj said.
Parents, students: pros and cons
Tony Djukic, a parent in Brampton, Ont., said his daughter Karen was often bullied at her previous school because the government did not do enough to curb bullying. Karen relied on her cell phone to talk to her parents to get help.

Zhukic believes that the mobile phone is her daughter’s lifeline and a tool that allows her to obtain personal safety and emotional support more quickly.

Karen got permission from her vice-principal to FaceTime her father when she was feeling down.

Ontario’s regulations banning mobile phones (except for learning purposes) in classrooms came into effect in November 2019, but Karen said that according to her observations, students who have mobile phones can use them at any time if they want to, including in class.

Zhukic questioned how teachers can prevent students from using mobile phones if they cannot stop students from bullying.
Katie Yu, a 17-year-old student in Iqaluit, Nunavut, said cellphones are important for safety reasons. She also uses her phone to search, take notes and plan extracurricular activities, but keeps it locked away during much of class. She said students should regulate their cell phone use.

Saskatoon student Connor Merson-Davies, 15, said he uses his phone a lot in class. Sometimes, I take out my phone without realizing it, and it slips away for a while. He favors cell phone bans.

He said the Grade 10 health sciences teacher made a wooden box for students to put their phones in during class. Throughout the class, he found that he and his classmates were more focused on studying.

Xinhua News Agency, Beijing, February 1 (Reporter Hu Hao) Recently, the General Office of the Ministry of Education issued the “Notice on Strengthening the Management of Mobile Phones for Primary and Secondary School Students”, requiring that primary and secondary school students should not bring personal mobile phones into campus in principle. If there is a real need, parents must agree and apply in writing. After entering the school, the mobile phone should be kept by the school and is prohibited from being brought into the classroom.

Should mobile phones be allowed into campus or banned? This topic has been discussed for a long time, and both sides have their reasons. Those who oppose mobile phones entering campus believe that teenagers’ self-control ability is still insufficient, and some students with poor self-control are prone to be addicted to mobile phones, which affects their studies, damages their eyesight, and even exposes them to bad information such as violence and pornography. Other parents who support mobile phones entering campus believe that without mobile phones, children are like kites with broken strings and cannot communicate with their parents. Others have suggested that some homework requires them to be completed and submitted online, so how can they do it without a mobile phone?

Regarding how to solve the communication needs after the ban on mobile phones, the Ministry of Education has made arrangements in the notice: schools should include mobile phone management in the daily management of schools, formulate specific measures, clarify the unified place, method, and person in charge of storage, and provide necessary storage devices. The need for students to communicate with their parents should be solved by setting up public telephones on campus, establishing a communication hotline for class teachers, exploring the use of electronic student cards with call functions, or providing other convenient ways for parents to contact students.

The Ministry of Education also made it clear that schools should strengthen classroom teaching and homework management, and should not assign homework with mobile phones or require students to complete homework with mobile phones. Has the problem been perfectly solved here? In fact, the dispute over mobile phones entering campus is only the surface of the problem. The real core is how to guide children to use mobile phones correctly and reasonably.  cell phone jammer

In fact, many adults have been “kidnapped” by mobile phones, let alone primary and secondary school students.

A university in the United States conducted a 24-hour “no media” experience experiment on 1,000 students from 10 countries in the world, asking them not to use any multimedia devices including mobile phones within a day. Most of the students who went through this project said that losing their mobile phones made them “uneasy”, showing negative emotions such as irritability, anxiety, tension, depression, and many people did not even complete the entire project.

Zhang Hengzhu, deputy director of the Education Bureau of Xuanwu District, Nanjing, introduced that it has become a global consensus to control the use of mobile phones by primary and secondary school students in school. Italy, France, Germany, the United States, the United Kingdom, Japan and other countries have expressly prohibited students from bringing mobile phones into campus or classrooms. Some regulations stipulate that students can use mobile phones only under the guidance of teachers and parents. Finland prohibits the sale of mobile phones to students below the third grade of junior high school.

1. The basic principle of cell phone jammers

Mobile phone signal blockers, as the name suggests, are devices that can block mobile phone signals. Its working principle is mainly to transmit interference signals with the same frequency band as the mobile phone communication band, so that the mobile phone cannot establish a normal communication connection with the base station. In this way, the mobile phone cannot make calls, send text messages or use other communication functions. Mobile phone signal blockers are widely used in various occasions where silence is required or information leakage is prevented.

2. Technical advantages of mobile phone signal blockers
1. Efficient shielding: Modern mobile phone signal blockers use advanced interference technology, which can achieve efficient shielding of multiple mobile phone communication frequency bands, including but not limited to 2G, 3G, 4G and even 5G frequency bands;
2. Intelligent control: High-end mobile phone signal blockers are equipped with intelligent control systems, which can adjust the range and intensity of shielding according to actual needs, which not only ensures the shielding effect, but also avoids unnecessary interference to the surrounding environment;
3. Safe and reliable: The design of mobile phone signal blockers fully considers the impact of electromagnetic radiation on human health to ensure that no harm will be caused to the human body during use.

3. Application fields of mobile phone signal blockers
1. Educational examinations: In order to prevent candidates from cheating with mobile phones and ensure the fairness of the examinations, mobile phone signal blockers are generally installed in various examination rooms;
2. Government agencies and military facilities: In order to prevent information leakage and ensure the safety of important meetings and activities, mobile phone signal blockers are also installed in government agencies and military facilities;
3. Cinemas and theaters: In order to ensure the continuity of performances and the audience’s viewing experience, these places will also use mobile phone signal blockers to avoid interference from mobile phone ringtones.

4. How to choose a mobile phone signal jammer manufacturer?
1. Technical strength: give priority to manufacturers with independent research and development capabilities and strong technical strength;
2. Product quality: product quality is the key factor in selection. High-quality jammers can provide more stable and efficient shielding effects;
3. After-sales service: good after-sales service can ensure the long-term stable operation of the jammer and promptly solve the problems encountered by users during use.

5. Future development trend of mobile phone signal jammers
With the advancement of science and technology, mobile phone signal jammers are also constantly developing and innovating. The jammers of the future will be more intelligent and precise, and can better meet the needs of different users. At the same time, with the popularization of 5G technology, jammers also need to be constantly updated to adapt to new communication frequency bands and technical requirements.

Poor cell phone reception can happen almost anywhere, including public schools. However, whether there is a specific cause for these signal blind spots has led to much speculation. Some suspect these areas of poor signal may be due to the use of cell phone jammers.

A cell phone jammer is a device that blocks cell phone signal transmission or interferes with cell phone signal reception. It interferes with communications between cell phones and towers by creating interference within the frequency range used by cell phones. Although these devices are illegal to manufacture, import, sell, or use in the United States, some people use them in certain settings, especially schools.

The case of cell phone jammers in schools
In 2015, a school district in Pasco County, Florida, enacted a policy requiring students to turn off cell phones and other mobile devices during school hours. However, when this policy failed to significantly change student behavior, one teacher decided to take more drastic measures.

Science teacher Dean Liptak was unhappy with students being glued to their smartphones in class and not paying attention, so he used a cell phone jammer to solve the problem. According to the Tampa Bay Times, Liptak activated the jammer between March 31 and April 2. At first, the strategy seemed to work, with students using their phones less frequently. However, problems soon surfaced when Verizon technicians discovered that the network near Fivay High School was experiencing interference.

After an investigation, Verizon determined that the interference originated from Liptak’s jammer, which it said not only affected cell phone signals inside the school but also interfered with communications outside the school. Liptak explained that his original intention was simply to reduce student distractions, not to cause trouble or intentionally break the law. He believes that good-intentioned uses should be allowed.

School District’s Response and Legal Consequences
However, the school district disagrees with Liptak’s perspective. Superintendent Kurt Browning made clear in a letter to Liptak that his actions not only potentially violated federal law but also posed a serious threat to safe communications during emergencies. Jammers may prevent students and staff from making 911 calls, which poses a significant risk to school safety management.

Ultimately, Liptak was suspended for five days. Browning emphasized in the letter: “Regardless of your original intention, the use of jamming devices is illegal. Your actions not only interfere with legitimate communications, but may also pose a threat to security.”

Legal and Ethical Issues with Cell Phone Jammers
The use of cell phone jammers is legally and ethically problematic. According to the Federal Communications Commission (FCC), unauthorized signal jammers can interfere with legitimate uses of spectrum, disrupting wireless signals and emergency services that daily life relies on. FCC Chairman Jessica Rosenworcel has made it clear: “You cannot manufacture, import, sell, transport or operate them. Whether for use in businesses, classrooms, homes or vehicles, they are not allowed.”

Additionally, while signal jammers can be used by law enforcement officers in certain circumstances, their use for other uses, particularly in schools, has been controversial. For example, the use of jammers in prisons to prevent prisoners from illegally using mobile phones is still under discussion. In 2019, Arkansas Senator Tom Cotton unsuccessfully attempted to pass legislation allowing the use of jamming devices in prisons.

CTIA, the major trade association for the U.S. wireless industry, said that solving the problem of banned mobile phones requires multi-party cooperation and recommended the use of solutions such as managed access systems to intercept illegal calls while protecting legitimate communications. The industry has committed significant resources to helping corrections officials respond to this problem and is working with all levels of government to implement effective solutions.

The worldwide phenomenon of signal jammers
The use of cell phone jammers is not limited to the United States, similar problems exist around the world. For example, ZDNet reported on a French father who used a signal jammer to prevent his children from using social media late at night, but inadvertently cut off internet access for an entire town. Incidents like these highlight the consequences of the inappropriate use of signal jammers, which, even with good intentions, can have an impact on the wider community.

Despite many measures, mobile phones in prisons are still rampant and can be used by prisoners to continue committing crimes. Thousands of mobile phones are confiscated in UK prisons every year, but a large number of them are still undetected and are smuggled in or thrown into prisons.  cell phone jammer

Mobile phones are a valuable resource for prisoners, and it costs between £400 and £1,000 to borrow one. According to the National Offender Management Service (NOMS), 7,451 mobile phones and Sim cards were seized outside prisons in England and Wales in 2013. Prisoners use these phones to plan murders, escapes, and import weapons and drugs. The problem is widespread.

For example, one prisoner used a mobile phone in his cell to organize crime and smuggle machine guns into the UK, while another prisoner ran a cocaine ring and planned murders and other crimes. The mother of a prisoner at Northumberland Prison said that mobile phones were everywhere in the prison, some of which were thrown over the fence, while others were brought in through specific routes.

Despite the prison’s various security measures, including signal detectors, metal detectors and specially trained police dogs, mobile phones continue to flow in. The management company of Northumberland County Prison said that staff are working hard to prevent illegal items from entering, but the effect is limited.

Challenges of mobile phone jamming technology
Mobile phone jamming technology is considered a potential solution. Common jamming methods include the following:

Interference/jamming: Blocking mobile phones from receiving base station signals by sending signals. This method is low-cost and effective, but it may interfere with signals outside the prison.

Grabbing: Mobile phones are attracted to false networks and specific mobile phones can be selectively blocked. This method is more expensive than full jamming.

Operator disconnection: The Serious Crime Act 2015 gives the government the power to force mobile phone operators to disconnect the network, but relevant regulations have not yet been promulgated.

Interception and search: Search visitors and staff for mobile phones, and use sniffer dogs and other means to find mobile phones.

NOMS believes that the cost of installing jamming equipment across the board is too high, up to £300 million, and the annual maintenance cost is £800,000. However, Howard Melamed, president of Cell Antenna USA, and Steve Rogers, general manager of Digital RF, believe that the cost of the technology is exaggerated, and the variety of prison types in the UK makes pricing difficult.

The gap between law and actual implementation
The Crime and Security Act 2010 stipulates that possession of mobile phones in prison can be sentenced to up to two years’ imprisonment and/or an unlimited fine. But Glyn Travis of the Prison Officers Association (POA) said that prisoners are not worried about the punishment for crimes committed in prison.

Despite regulations and pilot programs, the problem of mobile phones in prisons remains serious. The government once awarded a contract worth £60,000 to study how to prevent mobile phones from entering prisons, but the results were not obvious.

The Serious Crime Act also introduced the possibility of forcing operators to disconnect the network, but the regulations have not yet been implemented. Steve Rogers pointed out that even if the network is disconnected, prisoners will quickly change Sim cards and mobile phones.

Implementation and difficulties of blocking technology
Although blocking technology can effectively disable mobile phones, the Prison Service is cautious about it. Prisons need to urgently reform, adopt new technologies to find and block mobile phones, and provide prison officers with the necessary tools.

Steve Rogers believes that prisons can measure the success of technology by monitoring the number of banned mobile phones. The prison administration listed detection equipment, routine searches, closed-circuit television, police dogs and penalties, but did not specify what technology is used to block mobile phone signals.

The mobile phone is not broken but cannot be dialed, what’s going on? It turns out that there is a device called “mobile phone killer” that forces your mobile phone to block the signal; another bag called “mobile phone rest bag” allows you to actively choose to block the signal. The reporter learned that these two products of different natures are facing different fates: the former has been initially recognized by the market – Nanjing’s Panda Group even plans to sell 30 million yuan this year; the latter has been hiding in the market. “Mobile phone killer”: huge market, legality to be proven. cell phone jammer

“Mobile phone killer” is a nickname for mobile phone signal blockers, and its coverage radius is generally between 20-50 meters, that is, within this range, all mobile phones cannot make outgoing calls or incoming calls. It is understood that the average market price of this type of “mobile phone killer” is about 5,000 yuan. The largest user group is currently gas stations, theaters and libraries. Since these areas are not suitable for using mobile phones, and forced shutdown seems abrupt, they simply use this machine to destroy the signal and make the mobile phone “dumb”. According to preliminary statistics, there are more than 1 million places in China that need mobile phone communication blockers, so more than 10 manufacturers have already entered this attractive market. The emergence of “mobile phone killers” has been warmly welcomed by citizens who suffer from “mobile phone pollution” and managers of specific public places. But soon, legal professionals questioned its legality: whether such mobile phone signal blockers can be used in public places is not stipulated by laws and regulations; and if there is no authorization from laws and regulations, managers of specific public places will set up such equipment on their own, forcibly block personal communications, and deprive individuals of the right to obtain smooth communications, which may also be a problem of infringement. Others are worried that “mobile phone killers” are based on the premise of destroying telecommunications signals. To some extent, they have disrupted the wireless communication order in the region. If they are used by some lawless elements, it will obviously have a counterproductive effect. Therefore, it is called for a monopoly on this “double-edged sword” machine to ensure that it is used in legal ways.

“Mobile phone rest bag”: meets the needs, but vulgarization has hidden concerns

“Mobile phone rest bag” is just a small bag with some nano materials added, but don’t underestimate it. As long as your phone is in the bag, it will enter the “sleep” state. When others call your phone, they will all receive a prompt that “the user you are calling is temporarily out of service area”.
It is reported that the first group of exhausted white-collar workers were happy to accept the “mobile phone rest bag”. “I work in technical support for a foreign company. Although I dress brightly and look very proud all day long, God knows how much pressure I am under. The boss will call me at any time to arrange overtime, and the customer’s call will come in at any time within 24 hours. Sometimes I really hate such advanced technology and communication, because they force me to have no private time and private life except for work. But there is no legitimate reason to turn off the phone directly.” A white-collar worker confessed the original intention of buying it.

However, with the release of the movie “Cell Phone”, another round of “cell phone rest bags” has become extremely popular, which has made the inventor, Tang Tai, chief engineer of Tsinghua University, laugh and cry – because its use has been quickly limited to the vulgar level of private affairs between men and women. “The wife is always tracking, the boss is always asking for overtime. The lover is always asking for a date, the customer is always asking for the bill…” This limerick appeared in the reporter’s mailbox yesterday. It is the beginning of a promotional email. The promotion target is “cell phone rest bags”. Then the email also wrote seriously: the applicable people are those who are threatened by hacker phones, those who do not want to be disturbed by mobile phone ringtones, husbands, wives, lovers…

It is intriguing that the “cell phone rest bags” that are hot-selling online and cost less than 200 yuan are hard to find in real life. A staff member of a large communication market in Nanjing pointed out to reporters this morning that no matter what the purpose of causing oneself to be out of service area is, one thing is certain, those who want to buy “cell phone rest bags” do not want to be too ostentatious, so they would rather choose more secretive online shopping or mail order.

Every year during the college entrance examination, the school will have network problems, such as mobile phone disconnection and slow Internet speed, because the school has turned on the mobile phone jammer. If we think of mobile phones as handheld two-way radios, radios will be interfered with, and mobile phones are no exception. Like any radio, mobile phone signals are interfered with.  cell phone jammer

Interference principle
Interfering with mobile phones is like interfering with any other type of radio communication. Mobile phones communicate with their service network through base stations. When mobile phone users drive on the street, the signal switches from one base station to another.

Frequency range of the three major operators
We know that wireless communication uses electromagnetic waves for communication. The functional characteristics of electromagnetic waves are determined by their frequency. Our mobile phones must emit electromagnetic waves that meet the requirements in order to connect to our communication operator base stations. Different communication systems use different frequencies, so everyone is calm and will not interfere with each other. The basic principle of mobile phone jammers is to transmit the same radio frequency as the mobile phone. Because the frequency is the same, the mobile phone cannot distinguish which signal is the normal base station signal, thus achieving “interference”. The noise covers the traditional sound.

When the base station tries to connect to the mobile phone, as long as there is a machine with the same frequency as the mobile phone that emits high-power “noise”. You will find that the signal from the mobile phone is too complex to be recognized, so you will refuse to communicate with the mobile phone. Early jammers can only block one set of frequencies, such as 2G, while complex jammers can block several types of networks at the same time, such as 2/3/4G. How is this multi-network interference achieved?

Actually, it is very simple. In a looping manner, the interference bands corresponding to the three signals are repeatedly played, covering three bands at a time, and the intervals between the loops are very small, so that the mobile phone has no chance to talk and can only sit quietly.

Multi-band signal jammer
2/3/4G are all covered, so what about Bluetooth and wifi? It doesn’t matter, it can be handled. The jammer has evolved again, adding the frequency bands of Bluetooth and wifi to the scanning range, so that several common communication methods in society are completely covered. Many people do not understand the difference between Bluetooth, Wi-Fi and mobile data. They all seem to be wireless communication technologies, but the difference between the three of them is mainly in the frequency band. In mobile communication technology, 2G mainly works in the 900-1700MHz frequency band, 3G works in the 1900-2100MHz frequency band, and 4G works in the 2300-2500MHz frequency band. Bluetooth and WiFi work in 2.4GHz. The main principle of signal shielding and signal jammers is to emit huge noise in the frequency band used by mobile phones, disrupting the normal reception and transmission of mobile phone signals. This small object is not only used to prevent cheating during exams, but is also often used in politics and military to prevent terrorist attacks. But signal jammers are not like buying groceries and shopping. You can’t just buy and use them casually, otherwise it may involve breaking the law.

The mobile phone signal jammer uses the latest Israeli interference technology to generate a stable magnetic induction signal, covering the mobile communication GSM, CDMA, GPRS, local telephone, and PHS frequency bands, so that the mobile phone can operate in a certain designated location. It cannot be used to solve some of the adverse effects caused by data signals in today’s daily life. So do netizens know how to eliminate blocked data signals?

cell phone jammer

Detailed introduction to signal jammers on mobile phones:

Currently, the common mobile phone signal jammers on the market have functional working frequencies: 869~894MHz; 925~960MHz; 1805~1880MHz and 1900~1990MHz, etc. The functional frequency bands are CDMA800, GSM900, DCS1800, and PCS1900. It can operate an area with a diameter of 40 meters and uses a DC-DC inverter circuit to input working voltage and output voltage of 5V.

After the release of 3G signals, the working frequency bands of signal jammers on mobile phones currently on the market have also been increased from the previous four frequency bands to five frequency bands. On the basis of the previous four frequency bands, an additional 2100 to 2200 frequency bands have been added. This frequency band is used to block and influence the 3G frequency band. It uses memory overclocking, crossover, frequency hopping filtering and other technologies for the uplink and downlink channels of the mobile phone system to analyze the necessary shielding frequency.

According to the power size of the signal jammer, a ball is made to shield the space, and the electromagnetic field is automatically generated within the specified range, so that mobile phones (including PHS-China Telecom, PHS, GSM-China Unicom, China Mobile, CDMA-China China Unicom) is not valid on mobile phones within this indoor space. When the signal jammer is in operation, it can invalidate the signal receiving and sending functions of mobile phones within a specific range, making it impossible to dial in and out, thus achieving the purpose of forcibly prohibiting use.

How to decipher the signal jammer on your mobile phone:

Decryption method one: Go to the phone settings, click on “Network Connection Settings”, change the network mode to “Manual Mode”, then enter “Website Search” until the words “China Mobile” or “China Unicom” appear. Just pull out immediately. There will be a signal on the mobile phone, but the length of the anti-blocking time depends on the quality of WeChat. This method is available on most mobile phones.

Basic principle: The mobile phone works within a certain operating frequency range. The mobile phone and the communication base station are connected through ultra-wideband, and data and sound are transmitted at a certain serial port baud rate and deployment method. Then the signal jammer transmits to the high-end scanner at a certain rate from the mid- to low-end frequency bands of the wireless channel during the operation process. This scanning rate may cause errors in the packet format signals received by the mobile phone. The mobile phone cannot detect the normal data transmitted from the base station, making the mobile phone unable to establish a connection with the base station. The main symptoms on the mobile phone include network search, poor signal, and no service system.

Decryption method two: use 3G Internet.

Deciphering method three: Use Bluetooth: Document the answer on your mobile phone. Use Bluetooth to send files.

Deciphering method four: Use wireless network (alias wifi or wlan).

Decryption method five: Use another working frequency to destroy the working frequency of the shielding device.

A cell phone signal jammer is an electronic device designed to interfere with and block communications between mobile phones and base stations. It prevents mobile phones from receiving and sending signals by sending strong radio waves that cover the frequencies used by mobile phones. This device has a variety of uses, including protecting privacy, preventing information leakage, and controlling communications. However, the use of cell phone signal jammers is also accompanied by legal and ethical disputes. This article will explore in detail the working principles, uses, legal provisions, and social impact of cell phone signal jammers.

The core principle of a cell phone signal jammer is to interfere with communications by emitting radio waves at the same frequency as the mobile phone. Specifically, the jammer generates strong radio signals that cover the receiving frequency of the mobile phone, making it impossible for the mobile phone to receive useful information from the base station, and it is also impossible to send data to the base station.

cell phone jammer

1. Signal coverage
Cell phone signal jammers transmit interference signals through antennas, and these signals form a coverage area within a certain range. Within this area, the mobile phone signal will be interfered with, resulting in communication interruption. The effective range of the jammer depends on its power and design, which can range from a few meters to hundreds of meters.

2. Multi-band interference
Modern mobile phones use multiple frequency bands for communication, such as 2G, 3G, 4G and 5G. In order to effectively interfere with mobile phone communications, jammers are usually designed to cover multiple frequency bands. At the same time, some advanced jammers can also selectively interfere with specific frequency bands as needed to achieve more precise control effects.

3. Modulation method
The modulation methods of the interference signal are also varied, including sweep modulation, broadband noise modulation, etc. These modulation methods are designed to maximize the coverage of the receiving frequency of the mobile phone and ensure the interference effect.

Uses
Mobile phone signal jammers have practical application value in some specific occasions. However, the legality and morality of their use are often questioned.

1. Privacy protection
In some meeting rooms, confidential places or important business negotiations, the use of mobile phone signal jammers can prevent information from being leaked through mobile phones. By blocking mobile phone signals, it can ensure that no one can record, record or send information through mobile phones, thereby protecting privacy and sensitive information.

2. Examination venues
In order to prevent students from cheating in exams, some examination centers will use mobile phone signal jammers. This can effectively prevent students from getting outside help through mobile phones and ensure the fairness of the exam.

3. Security
In certain places with high security requirements, such as prisons, military bases or important government agencies, mobile phone signal jammers can prevent unauthorized communications. This can prevent insiders or outsiders from conducting illegal activities through mobile phones, such as smuggling, escape plans or leaking confidential information.

4. Public places
In certain public places, such as cinemas, theaters or libraries, the use of mobile phone signal jammers can prevent mobile phone ringing and calls from disturbing others, thereby maintaining public order and a quiet environment.

1. United States
In the United States, the Federal Communications Commission (FCC) prohibits any unauthorized individual or business from using, selling or marketing jamming devices. The FCC believes that jamming devices will interfere with public communication services and threaten public safety. Therefore, it is illegal to use mobile phone signal jammers unless special permission is obtained.

2. Europe
European countries also have strict regulations on mobile phone signal jammers. EU member states generally prohibit private individuals and companies from using jamming devices, and only specific government agencies and organizations with special licenses can use them.

3. Asia
In Asia, legal provisions vary. For example, China has strict restrictions on the use of jamming devices, which are usually limited to specific places authorized by the government. In Japan, the use of mobile phone signal jammers is almost completely banned.