カテゴリー別アーカイブ: cellphone

The National Labor Relations Board (NLRB) has earlier endorsed a workplace policy that prohibits employees from using cell phones for safety reasons. Furthermore, the Federal Communications Commission (FCC) has recently confirmed a fine levied against an employer for the use of signal jammers to block employees’ access to cell phones during work hours.

Devices known as signal jammers are designed to suppress, block, or interfere with authorized radio frequencies and communications, and their use is prohibited under the federal Communications Act of 1934, as amended (the “Act”), with certain limited exceptions. The presence of mobile jammers poses a serious threat to public safety by preventing individuals from contacting emergency services via 911, disrupting the communications of first responders, and interfering with critical safety communications in both aviation and maritime contexts.

Under the provisions of the Act, the use or operation of any device designed for the transmission of energy, communications, or signals by radio is prohibited within the United States unless it is licensed or authorized. Additionally, the Act clearly states that no person shall intentionally or maliciously disrupt or interfere with the radio communications of any station that is licensed or authorized under this chapter or operated by the United States Government.

Additionally, the Act specifies that “No person shall engage in the manufacture, importation, sale, offering for sale, or transportation of any device or household electronic device or system that does not comply with the regulations issued under this section, nor shall they operate a device that is not in compliance with the regulations established under this section.” Such regulations require that radio frequency devices obtain authorization from the Federal Communications Commission before they may be utilized.

As a result, a jamming device is ineligible for certification or authorization due to its fundamental purpose of blocking or interfering with authorized radio communications. The utilization of such a device would jeopardize the integrity of the nation’s communications infrastructure. Therefore, a jamming device does not conform to the technical standards set by the FCC and is not permitted for legal use within the United States.

The FCC Enforcement Bureau initiated an investigation into a warehouse business located in Texas after receiving a signal interference complaint from AT&T. The business owner admitted to utilizing a signal jammer to restrict employee cell phone usage during work hours. According to the FCC, the owner acknowledged that her son had been informed by an AT&T representative that the use of a jammer was against the law. Moreover, the owner conveyed to FCC agents that she had discarded the jamming device and was not inclined to recover it or disclose its location, although she did offer to sell the device to the agents, which they declined.

The widespread integration of wireless communication devices has resulted in extraordinary convenience. Although these devices have revolutionized our interactions and access to information, they can also create issues related to interference, privacy breaches, and security threats. When used responsibly and within legal boundaries, signal jammers can produce numerous advantageous effects that improve daily life.

How do signal jammers enhance security and privacy?

Signal jammers are instrumental in reinforcing security measures and protecting privacy. In areas of high sensitivity, including government buildings, military installations, and secure facilities, the use of signal jammers effectively curtails unauthorized wireless communications, thereby diminishing the risks associated with espionage, hacking, and unauthorized recording. Moreover, signal jammers play a significant role in safeguarding personal privacy in public venues by obstructing unauthorized filming or recording, thus providing individuals with enhanced control over their privacy.

Frequency jammers can play a crucial role in enhancing concentration and productivity within certain environments. In areas that require quiet and focus, such as classrooms, libraries, and office spaces, these devices can help alleviate disturbances from ringing phones, unauthorized wireless device activity, and disruptive sounds. This can ultimately lead to an environment that is more supportive of learning, concentration, and effective communication, thus improving overall productivity and efficiency.

How do cell phone signal jammers block signals?

A variety of approaches can be employed to block cell phone signals, with cell phone jammers being the most common. These devices transmit designated radio frequencies that disrupt the communication between a cell phone and the nearest base station, effectively preventing the phone from making calls, sending text messages, and accessing the internet.

Another method to inhibit cell phone signals is by employing a signal-blocking box or bag. These devices are often crafted from specific materials that efficiently isolate electromagnetic signal interference, effectively creating a “dead zone” for the phone, rendering it incapable of receiving any signals.

What is the effective range of a cell phone signal jammer?

The range of a cell phone signal jammer can vary significantly, contingent upon its power output and design features. Smaller, portable jammers may possess a limited range of just a few meters, which makes them suitable for use in compact settings like classrooms or meeting rooms. On the other hand, more robust jammers can operate over distances of hundreds of meters, efficiently blocking signals in expansive areas.

Carr Seeks Federal Solutions Address Proliferation Contraband Cell Phones Within Correctional Facilities

ATLANTA, GA – Attorney General Chris Carr is urging the Federal Communications Commission (FCC) to take immediate action to allow for the use of cell phone jamming devices within state prisons and local jails. The FCC currently prohibits the use of cell phone “signal jammer,” and that prohibition extends to state and local governments. Yet in prisons and jails throughout the country, contraband cell phones are being used to plan and orchestrate violent attacks and other criminal activity, posing a real and substantial safety risk to correctional officers, visitors, inmates, and the public at large.

“The easiest way to protect the public from the harms caused by contraband cell phones is to allow for the use of cell phone jamming technology in prisons and jails, but the FCC continues to block our efforts,” said Carr. “This outdated guidance limits legitimate law enforcement tools, presents dangerous conditions for correctional officers, and allows for the escalation of criminal networks both inside and outside prison walls. We’re committed to combatting violent crime wherever it occurs, which is why we continue to call on the federal government to remove this substantial barrier to public safety.”

In Georgia alone, 8,074 contraband cell phones were confiscated in 2023, with 5,482 confiscated to date in 2024. Recently, an incarcerated leader of the infamous street gang, “Yves Saint Laurent Squad,” used a contraband cell phone to order a hit which resulted in the death of an 88-year-old Georgia veteran. A gang leader in North Carolina was able to order the kidnapping of a prosecutor’s father via a cell phone in prison. In California, prison gangs used contraband cell phones to order murders within the prison system and traffic drugs.

“There are hundreds of examples from across the country of how a contraband cell phone in the hands of an inmate can be used as a deadly weapon and gives them the ability to continue their criminal enterprise. We are incensed by the length these individuals go to in continuing those activities and endangering the public,” said Georgia Department of Corrections Commissioner Tyrone Oliver. “As attempts to infiltrate our facilities with contraband cell phones evolve, access to jamming technology is paramount in our efforts to combat those attempts. We appreciate the support of Attorney General Carr in our ongoing commitment to public safety and the safe operations of our facilities.”

In his letter, Carr notes that the FCC policy relies on a statute enacted in the early 1990s, years before prison inmates began using contraband cell phones to plan and engage in unlawful and dangerous activity.

Carr further states: “Nothing in the language of 47 U.S.C § 333 prohibits the FCC from revising its position to allow state agencies to use cell phone jamming devices in prisons. In fact, the United States Bureau of Prisons has recognized the potential value of cell phone jammer already and is permitted to use jamming devices at several federal penitentiaries, including at least one in Georgia.”

In January 2023, Carr joined a 22-state coalition of attorneys general in urging Congressional leaders to pass legislation that would allow states to implement a cell phone jamming system in correctional facilities.

Carr’s Gang Prosecution Unit has also partnered with the Georgia Department of Corrections (GDC) to investigate and prosecute currently incarcerated individuals who are alleged to have engaged in criminal gang activity and discussions regarding the packaging and shipping of contraband items into a GDC facility.

Generally, radio signal shielding is only approved when important situations such as the college entrance examination occur. Moreover, from the perspective of the “control area”, signal shielding in our school does not exist. According to many students, signal shielding not only covers the nearby corridors, but also seriously affects the quality of self-study. In addition, according to our tests, outside the school, near the corridor of Qinsu Building, the signals of operators are interrupted one after another. Taking China Mobile as an example, the signal is about 20dBm lower than when it is not installed, and the SINR signal-to-noise ratio has also dropped from the normal 11-15 to 3-8. The value of the signal has greatly changed the function of the Internet. We noticed that even passers-by passing by the school will send out false signals on their mobile phones. Portable WiFi jammers in the classroom should not be missed. We collected data. In order to obtain more accurate analysis data, we will next conduct in-depth communication with the three major operators.

We noticed that several third-grade students have communicated with relevant teachers and principals, but the communication has not yet achieved any results.

Even in the eyes of some people, the quality of students’ learning is indeed “guaranteed”. However, we must not believe that installing mobile phone jammers is an ideal method. Because no matter what method is used to ensure the quality of learning, it cannot exceed the upper limit prescribed by law. Teachers can take other consistent and reasonable measures to ensure the quality of students’ learning. Installing mobile phone jammers in the classroom not only seriously violates students’ imagination, but also creates rebellious emotions in students’ hearts, leading to alienation, breakup and even conflict between students and schools, causing greater harm to students.

In the process of collecting and analyzing data, we received a new message: in order to prevent students from turning off mobile phone jammers privately in class, the switching of some jammers may have been cancelled (to be honest, we hope this message is false). This completely eliminates the possibility of some kind of compromise-for example, turning on the mobile phone jammer during the test and turning it off at other times-pushing the above contradiction to an incompatible point. Many students said that they felt that the school no longer trusted them.

Block teaching area in teaching management

Some students who fainted in class may be texting on their mobile phones. If they don’t want to go to class during class, they don’t need to go to the nearest office to whisper and chat. Easily send and receive text messages on your mobile phone.

Nowadays, mobile phones can access the Internet, and students can often chat, read novels, and play games on their mobile phones during class.

The school installs and uses a smartphone jammer management system to prevent students from abusing their phones in class. However, when mobile phone signals are blocked in the classroom, some students say that the school violates the “students’” right to communicate freely. From the perspective of students who often use mobile phones, these views seem to make sense. But think about it carefully. If blocking mobile phone signals violates students’ right to communicate, then these students are using their phones during class or self-study. Have you ever thought that you have violated other students’ right to education? Have you ever thought about respecting the teacher’s teaching license? Whether it is rights or freedoms, there are only relative, not absolute. All rights or freedoms are based on respecting the rights of others. The law is also a rule based on the interests of the majority. This rule protects the rights of the majority. If we really want to talk about counterfeiting, the fact is that a few students use mobile phones at will regardless of the occasion, which violates the educational rights of most students.

Some students or parents may also suggest that the school block mobile phone signals in class. What if there is an emergency at home that needs to be contacted or the student himself is not notified? In fact, this question is not difficult to answer. From the student’s point of view, the reason why students use mobile phones is to facilitate their parents. In fact, as long as there is no emergency, students do not need to be in school 24 hours a day. In special cases, the school, teachers and parents will take the initiative to establish contact. Second, from the perspective of parents, I remember a few times when children were equipped with mobile phones because of special circumstances. If they had to make a phone call, they would immediately stop the class and let the school handle it?

NBC10 Investigators tracked down a cell phone sniffer who specifically targeted people using their cell phones on SEPTA bus routes. Not only did he admit to doing it, he thought it was a good thing.

The man, who calls himself Jonathan, told NBC10 Investigators, “I guess I’m taking the law personally, and frankly, I’m proud of it.”

Jonathan said he doesn’t want to hear people talking on their phones in public.

“It’s still pretty annoying, and frankly, it’s pretty rude,” Jonathan said. Jonathan

said he was activating a cell phone jammer he bought online to block out conversations he doesn’t want to hear.

“A lot of people are very loud and have no sense of privacy at all. When they feel like they’re bothering me, I just screw in the antenna and turn the switch on,” Jonathan said.

An NBC10 employee, whom NBC10 Investigators calls “Brooklyn,” said she was horrified when she saw the man jamming passengers’ cell phones while she was riding a SEPTA bus to work.

“He was clearly holding this device that looked like a walkie-talkie, with four thick antennas on it. I started watching him, and whenever someone started calling, he would press a button on the side of the device,” Brooklyn said.

Brooklyn tipped off NBC10 Investigators, who went undercover and caught the phone thief with hidden cameras.

Minutes after boarding the No. 44 bus, NBC10 Investigators spotted Eric jamming a cell phone. Weeks later, they caught Eric as he got off the bus and told him cell phone jamming devices were illegal.

“From what I understand, it’s more of a gray area. From what I understand, it’s illegal to stop TV signals, radio signals. From what I understand, it’s not illegal to jam cell phone signals under the FCC,” Jonathan said.

But under federal law, it’s illegal to use, possess, buy or sell a cell phone jammer. The federal government says violating the law could result in jail time and a fine of up to $16,000. Cell phone jammers are illegal for public safety reasons.

Dr. Rob D’Ovidio of Drexel University studies cell phone forensics and e-crime. D’Ovidio said some cell phone jammers can block GPS, two-way radios and even police radios if they are close enough.

“With a cell phone jammer, you can limit all types of communication tools that use radio frequencies. That has the potential to be a public safety disaster. It’s a dangerous thing to cut off not only our government officials from communicating with the dispatch center, but also the public from communicating with 911,” Dr. D’Ovidio said.

NBC10 Investigators asked Jonathan if he was worried about disturbing someone who was seeking emergency help.

“Certainly, if that happened on a bus, I think I would have been in that situation. Of course, I think that would have been a very different situation; I think I would have called 911 myself,” Jonathan said.

SEPTA officials said they have received many complaints from 44 bus route passengers about lost phones. But SEPTA insisted that passengers are safe, adding that they have tested their system and handheld signal jammer alone are not enough.

SEPTA said all buses are equipped with panic buttons. Drivers can also alert police via digital destination signs on the front of buses. The transit authority said it has tested two-way radio communications and insisted cellphone jammers wouldn’t affect it. But that didn’t make Brooklyn feel any better.

NBC News reports that online retailers and drone technology companies are marketing RF jammers as drone deterrents or privacy tools, thereby circumventing laws that prohibit the sale of such devices in the United States.

The warning issued by the Federal Communications Commission (FCC) states that signal jamming devices can block emergency calls and pose a serious risk to public safety communications, while also interfering with other forms of everyday communications and air navigation systems.

The FCC said: “It is a violation of federal law to use phone blocker, GPS blockers, or other signal jamming devices designed to intentionally block, disrupt, or interfere with authorized radio communications. Use in businesses, classrooms, residences, or vehicles is not exempt. Local law enforcement agencies do not have independent authority to use jamming devices; federal law enforcement agencies may use them under applicable regulations under certain limited exceptions.”

The FCC warning also states that “it is illegal to advertise, sell, distribute, import, or otherwise market jamming devices to consumers in the United States”

But NBC reports that Amazon third-party sellers, independent online stores based in China, and small domestic companies that specialize in drone-related equipment are all ignoring the law. The FCC told NBC that it is investigating the sale of jammers, including on Amazon.

As part of its investigation, NBC spoke with the CEO of a U.S. company that offers portable anti-drone radio frequency jamming devices online. The CEO told NBC that the devices are easily available if consumers have the money, but they mainly see interest from large companies and government agencies as they prepare for domestic drone terrorism.

There are more people selling “jammers.” The devices can block cell phone calls, text messages, Wi-Fi networks and GPS systems and can be used to cause chaos in public places.

The small, battery-powered devices can be used to create “blind spots” in a small area (usually around 30 feet) and have been used by movie theaters, restaurants and schools to prevent people from using their phones. But they can also cut off 911 calls, interfere with navigation near airports, and have been used to disrupt radio communications near police stations. FCC officials said they have noticed an increase in the flow of jammers, which are banned by federal law, into the United States. Many of the cheaper versions, which sell for as little as $25, are imported from Asia, according to the agency.

It is illegal to sell, advertise, use or import jammers under the Communications Act of 1934, which prohibits blocking radio communications in public

The FCC said cities including Orlando, Philadelphia, Austin, Mississippi, Charlotte, North Carolina, Washington, D.C., Cincinnati and Corpus Christi, Texas, advertised jammers on the site. Officials said they do not believe the cases are related.

“Simply posting an ad for a signal jammer on a site like Craigslist.org is a violation of federal law. Signal jammers are contraband for a reason,” Michele Ellison, director of the FCC’s enforcement bureau, said in a statement. “One person’s moment of peace or privacy could very well jeopardize the safety and well-being of others.”

Most sellers advertised jammers as a way to take an “undisturbed nap” on a bus, quiet a classroom or keep your area “free of interference,” without mentioning the more nefarious uses the device could be used for, according to the citations.

“We are increasingly concerned that individual consumers operating jammers do not appear to understand the serious consequences of using jammers,” one citation reads. “Instead, these operators mistakenly believe that their illegal operations are personal convenience or should be excused.”

Keith Grabowski allegedly advertised on Philadelphia Craigslist for a “cell phone jammer, WiFi signal jammer” for $300. He stated in the ad that “due to the nature of this item, we are disclosing very few details,” that the jammer was “not a toy,” and that “I just want to get rid of it as quickly as possible.”

What’s the context?

US prison officials harness new technology to crack down on contraband cellphones but some still want powers to jam signals

• South Carolina programme shuts off more than 800 phones
• Federal action on broader signal jamming tech seen as unlikely
• Activists raise privacy, rights concerns for prisoners

Digital privacy rights advocates and tech experts say even solutions less far-reaching than full-blown signal jamming – like the South Carolina pilot – threaten to trample on the rights of prisoners by, for example, sharing legally protected information with private phone companies or carriers.

Digital rights groups have long raised concerns over the push for cellphone jamming systems in prisons, describing them as overreach.

Under federal law, state and local facilities are not allowed to use jamming technology, which is opposed by the telecommunications industry amid concerns that it could knock out signals in areas surrounding prisons.

The Federal Communications Commission (FCC), which regulates communications technology in the U.S., has been wary of signing off on full-blown signal jamming but cleared the way within the last few years for states like South Carolina to implement so-called “contraband interdiction systems.”

Stirling is convinced signal jamming is a solid option but does not think it will be authorised in state prisons. It is already allowed in federal institutions.

“I would love to get jamming – I don’t see it happening, unfortunately,” he said.

Asked if the FCC was contemplating changes, a spokesperson pointed to the federal law banning jamming devices.

Albert Fox Cahn, founder of the Surveillance Technology Oversight Project (S.T.O.P.), says both jamming and interdiction systems like the one used in South Carolina are “chilling options” that could have unintended consequences.

Bearing a resemblance to a walkie-talkie, the phone blocker is a device of significant power. Once turned on, this small contraption can effectively block all cell phone signals in the nearby area. The use of such a device is not only a federal offense, but can also result in a substantial $16,000 fine and potential jail time.

Eric, a Philadelphia native, refused to be discouraged by the situation. He became increasingly fed up with the incessant cell phone conversations on SEPTA 44 buses. To avoid being subjected to these discussions, Eric resorted to activating a jamming device.

Eric noted that a large portion of the population is loud and shows no regard for privacy. To deal with the annoyance, he adjusts the antenna and turns on the device.

The use of jammers, like the ones utilized in this particular case, is against the law as they have the ability to block emergency cell phone communications and interfere with essential signals, such as police radios and other two-way radios.

Eric announced that since discovering its illegality, he is preparing to discard the jammer he bought, an item estimated to be worth $300 by ABC News.

Buying a jammer is easy, but where can you use it?

The deliberate interference with electromagnetic frequencies, also known as jamming, has been integrated into a range of devices and is increasingly being offered to individuals and organizations. Despite being illegal in most parts of the world, jammers are becoming smaller, more portable, easier to use, and cheaper. While some jammers block communications indiscriminately, there are specialized devices designed to block specific signals. The most popular among these are mobile phone jammers, wifi jammers, drone blocker, and gps jammers.

The reason why most national authorities disapprove of the use of these devices is that they tend to have a greater impact than expected. Even when used with good intentions, such as blocking mobile phone usage in schools, theaters, and hospitals, or preventing drones from flying over private property, the interference can extend far beyond the intended range. Unintended consequences like dropped 911 calls, drones falling from the sky, and impaired air traffic control have led countries like South Africa and Israel to make them completely illegal.

Jammers are commonly deployed around prisons and detention centers to hinder unauthorized and unmonitored communications between prisoners and detainees and the outside world. Some countries, such as Brazil, India, New Zealand, and Sweden, have granted exemptions or are contemplating exemptions for the use of mobile phones and wifijammer around prisons, while in the UK, this practice has been legal since 2012.

A number of countries have sanctioned or recommended the expansion of jammer deployment. In India, for instance, jammers can be utilized in educational institutions, places of worship, and entertainment venues as long as the signal disruption is contained within the boundaries of the respective locations. Although jammers were previously approved for use in settings such as theaters and concert halls, this authorization was terminated in 2012.

In the scenario where you find yourself in possession of a legally owned cell phone jammer, what options are available to you? It may be worth considering booking your next flight to Ukraine, as this country has implemented measures to prevent students from using mobile phones to cheat in exams. Consequently, Ukraine has become one of the few nations where the use of jammers is authorized.

A multitude of 5G signal jammer are currently available in the market. Certain devices are engineered to solely interfere with a single frequency, whereas others have the capability to block multiple network types concurrently. The latter mode seamlessly transitions between different networks, continuously searching for open signals. Premium devices can effectively block all frequencies simultaneously, while other devices can be fine-tuned to target specific frequencies.

Put simply, these devices emit random static or noise across a wide range of frequencies, leading to a failure in establishing proper connections. It’s like sitting next to the engine of a sports car, opening the hood, and trying to have a phone conversation. The localized noise becomes so intense that the device fails to connect effectively. Rapidly covering a certain frequency range can effectively prevent the device from functioning correctly.

The carrier frequency of the EMI signal aligns with that of the receiver, facilitating the concurrent demodulation of the interference signal. This analogy likens the process to transporting a model vehicle (carrier frequency) alongside counterfeit goods (interference signals). The determination of authenticity and falseness can only occur once the vehicle receives the goods. The shielding effect can be accomplished due to the substantial electronic interference power, which is limited by the interference signal.

The operational concept of a 5G cell phone jammer involves transmitting signals from a device that operates on the same frequency as the mobile signal source. Upon installation, the jammer can be activated to interfere with mobile signals in areas where their usage needs to be disabled. It is crucial to ensure that there are no obstructions present at the designated site for the interference to be effective. Considering the increasing number of mobile phone users, there is a growing demand to selectively disable mobile phone signals in specific locations through civilian-oriented means, as opposed to relying solely on electronic devices.

To safeguard mobile phone reception signals, a 5G wifi jammer is employed as an instrument that blocks them. The signal rates of cell phone signal blocking device modems are comparable to those of cell phone towers. When a mobile phone jammer is activated, the blocking of mobile phone signals is considered successful, resulting in their disablement.

Full-duplex mobile phones have the capability to use two frequencies simultaneously for transmitting and receiving signals. This synchronous signal processing ensures efficient communication. However, some 5G signal jammers are limited to blocking only one frequency at a time, resulting in both frequencies being blocked simultaneously. As a consequence, the phone may mistakenly detect a service outage in the area due to receiving only one frequency.

Emitting signals at a common radio frequency, 5G signal jammers can create interference. Devices designed for shielding purposes can disrupt the communication between cell phones and base stations. The act of blocking signals is also known as a denial of service attack, as it prevents users within the blocking device’s range from receiving radio signals.

Disabling mobile phones has the same impact on blocking 4G/5G signals as it does on other types of radio communications. To operate a cell phone, a signal must be sent from the phone to the nearest cell tower. In urban areas, there are multiple towers that facilitate signal transmission as users navigate through the city.

We are dedicated to supporting parents and guardians who aim to enhance online safety for children utilizing internet-enabled devices. Our service effectively filters out inappropriate digital content and enables tracking of the child’s online activities.

Dad Uses Signal Jammer to Stop His Kids from Going Online

Due to his unawareness, a resident living in the southwestern French town of Messanges might face a prison term of six months for inadvertently disabling telephony and mobile internet services in his local area using a signal jammers.

Surprisingly enough, his actions were not fueled by malice. His only intention was to restrict his teenage kids from using their mobile devices to go online once it was time to sleep.

According to the French planning and radio frequency management agency (ANFR), a complaint of an unusual nature was filed by a local mobile phone operator. The complaint highlighted the inconvenience faced by the residents of Messanges, who were unable to utilize their cellular and mobile internet services from before midnight until 3 AM every week.

The French planning and radio frequency management agency (ANFR) has reported an atypical complaint lodged by a local mobile phone operator. The complaint stated that the residents of Messanges faced an inconvenience as their cellular and mobile internet services were unavailable from just before midnight until 3 AM every day of the week.

In light of their investigation, the ANFR has established that a mobile phone jammer, a device prohibited in many European countries, including France, was responsible for interfering with radio frequencies in the area.

Around 1:30 am, a technician skillfully traced the source of the signal to a residence nestled in the coastal town. The following day, investigators, accompanied by police officers, proceeded to knock on the man’s door. Without any delay, the individual immediately admitted to utilizing a multi-band jammer.

The ANFR clarified that the father of the family had taken the step of installing a jammer to discourage his teenagers from using their smartphones to access the internet late at night. This decision was prompted by the children’s addiction to social networks and various applications. After consulting online forums, the father concluded that a jammer would be the optimal solution to address his kids’ excessive screen time.

Version 4: Besides demanding the owner to switch off the jamming wifi and refrain from using it, the ANFR agent emphasized the need to comply with the regulatory framework, as stated by the agency.