Mobile jammer can be adjusted as needed
Shielding mobile phone signals, as an important means to prevent candidates from cheating, is facing severe challenges with the advancement of technology. A few days ago, some parents broke the news that despite the installation of mobile phone jammers in the examination room, there are still candidates using mobile phones to search for answers online, which greatly reduces the authenticity of the test results. "The current jammers can only interfere with calls and text messages, but they cannot To interfere with the ability of 3G Internet access." The parent said. Are the facts as they say? Recently, the reporter made a special trip to conduct actual investigations and uncover the truth of the "loophole" for you——
Parents broke the news: Mobile Internet can escape shielding
"Now students cheating is becoming more and more high-tech. In daily larger exams, they use their mobile phones to go online, to search for answers in classical Chinese, and even test essays are plagiarized from the Internet. According to children, these students’ mobile phones interfere Nothing can help the computer. Students with average grades cheat with this, and their test scores are even among the best." Recently, citizen Mr. Wang called to reflect. In his eyes, the current mobile phone shielding devices have big loopholes. "They can only interfere with calls and text messages, but they cannot interfere with 3G Internet access. We should be alert to this."
Mr. Wang said that he discovered the above phenomenon, starting from a "injustice" to his daughter. In the mid-term exam not long ago, her daughter, who always excels in class, was accidentally squeezed out of the front. Mr. Wang was very angry about this, and as soon as he criticized a few words, he saw his daughter weeping aggrievedly. Later, my daughter, who usually doesn’t talk much, slowly explained the whole story: It turns out that the exam questions were written by outsiders, and I don’t want the original questions and standard answers to be searched on the Internet. Some students took the exam. She just used her mobile phone to search for answers, but she did it by herself.
"I was shocked when I heard this. I asked if there is a cell phone jammer in the examination room, why can I still access the Internet? My daughter explained that she did see some classmates' mobile phones and was not afraid to block the Internet." Then, Mr. Wang communicated with his daughter's teacher and got it. The reply confirmed that the daughter did not lie, and it was found in the examination room that some students were online.
"Cheating technology is advancing, but our shielding devices have been purchased for many years, so it is inevitable that there are loopholes, and if you do not take precautions, some children will be harmed." Mr. Wang said.
Reporter experiment: Wi-Fi Internet will break the "shield off"
Does the mobile phone jammer really only block calls and text messages, not 3G Internet access? Subsequently, the reporter made a special trip to borrow a mobile phone jammer used in daily examinations and college entrance examinations from a school in the city. I saw that the shielding instrument has four antennas, the shielding frequencies are 800MHZ, 1800MHZ, 900MHZ and 1900MHZ, and there are two adjustment switches for power "large" and "small".
The test environment is the reporter's office, a room of about 40 square meters with a small partition between the desks. There are 10 mobile phones in the room during the test. First of all, when the reporter turned on the shielding instrument power and adjusted the power block to "small", except for a Nokia phone with a "Global Connect" card inserted in the room, all other phones including Apple iphone3 and iphone4 could still make calls. If you can’t make and receive calls, it’s even more impossible to use it to get online. Then, when the reporter adjusted the power of the mobile phone jammer to "large", the results showed that 10 mobile phones of different brands, models and functions under test were all without any signal at this time.
Subsequently, the reporter conducted several tests in this way, and the results all proved that the current four-frequency shielding device used in the school is sufficient to shield most mobile phone calls, text messages and Internet functions within the effective range of interference. Then how did the students secretly search for the answers to the test papers on the Internet under such a strong interference environment?
In fact, anyone with a little knowledge of wireless Internet will know that the mobile phone can not access the Internet only by acquiring the mobile phone signal. As long as it has wireless LAN connection functions such as WI-FI or WAPI, it can also access the Internet via wireless LAN. Its biggest advantage is that it does not cost a mobile phone. The "traffic charge" in the card. Will this method be disturbed by mobile phone jammers? Subsequently, the reporter also conducted actual tests.
The reporter used an Apple iphone4 as the test object. When the mobile phone jammer was turned on, the cell phone signal area was quickly replaced with the word "No Service", and when logging in to the webpage, it displayed "Cannot open the webpage, safari (Apple browser) can't open it. This webpage is not connected to the Internet.” Then, the reporter took out a portable wireless router that supports the WI-FI output function, and at the same time turned on the WI-FI function of the iphone4 that participated in the test, and connected it to the wireless The router was successfully connected. When the reporter tried to open the Baidu webpage to search for "classical Chinese translation" with his mobile phone, the reporter was shocked by what happened. Not only did the webpage open smoothly, but the internet speed was not affected at all. The search results of various classical Chinese translations were displayed. on the screen. Afterwards, the reporter found mobile phones of HTC and other brands that support WI-FI function to perform the above tests repeatedly, and the results all showed that the existing mobile phone shielding device was "helpless" for mobile Internet access using WI-FI function.
In other words, as long as you have a portable wireless router, even if you put it on the podium or in the hallway outside the examination room along with the "irrelevant test supplies" during the test, as long as the mobile phone has escaped inspection, the test taker can still access the Internet if he takes out his mobile phone Find any information you want. The more serious situation is that with the popularization of wireless network technology, there are already dense and invisible wireless networks around us. Even if there is no need to purchase a portable wireless router separately, as long as the corresponding permissions are obtained, these wireless networks may be candidates. Cheating provides an opportunity. Break the "shield off"