Signal jammers are used in important exams such as college entrance examination, grade four and six, graduate exams, etc., and shielding devices are used to prevent candidates from cheating. However, there will always be people who want to crack mobile cell phone jammer, and they have seen cracking mobile phone signal interference on the Internet. Several methods of the device, this article mainly analyzes whether these methods have any effect.
Let's first look at the working principle of some mobile phone signal jammers
Within a certain frequency range, the mobile phone and the base station are connected by radio waves, and data and sound transmission are completed with a certain baud rate and modulation method. The mobile phone jammer scans from the low-end frequency of the forward channel to the high-end at a certain speed during operation. The scanning speed can cause garbled interference in the message signal received by the mobile phone. The mobile phone cannot detect the normal data sent from the base station, so that the mobile phone cannot establish a connection with the base station and achieve the purpose of shielding the mobile phone signal. No service system and other phenomena. Generally speaking, the frequency emitted by the mobile phone signal jammer interferes with the normal frequency of the mobile phone receiving the base station, making the mobile phone unable to connect to the base station, and thus unable to make calls, receive and send text messages, and surf the Internet normally.
Cracking method one
Modify the mobile phone network mode: enter the phone settings, click the network settings, change the network mode to manual mode, enter the search network, and exit immediately after the words China Mobile or China Unicom appear. The mobile phone can receive the signal, but the length of the half-blocking time depends on the quality of the mobile phone. This method is suitable for most mobile phones.
This method is incorrect, because the mobile phone jammer is shielded for all mobile phone frequencies under the three operators, so no matter how you switch, it will be shielded, which means that no matter what the mobile phone card is, the signal is jamming. Within the shielding range of the device. Fundamentally speaking, any mobile phone signal frequency exists in the shielding range of the signal shielding. The signal shielding is responsible for scanning and transmitting the same frequency band. If the quality of the mobile phone is not good, it may be faster than the signal shielding, so any switching is possible. Hidden.
Cracking method two
Modify the mobile phone receiving frequency band: The working principle of shielding is to shield the mobile phone by interfering with the mobile phone signal of the specified band. Most mobile phone jammers can only shield the mobile phone signal of 900---1800MHZ. Therefore, modifying the receiving and transmitting frequency of the mobile phone can prevent shielding. The receiving and transmitting frequency is far greater than the shielding range of the shield. Therefore, in the mobile phone settings, adjust the receiving and transmitting frequency of the mobile phone to the maximum to receive the mobile phone signal normally.
This method is invalid. Mobile phone signal jammers are not only shielding individual frequency bands, such as MDPB-16W 5G signal jammers. The transmission frequency bands include CDMA frequency frequency 870-880MHz, GSM frequency frequency 935-960MHz, DCS/PHS Segment transmission frequency 1805-1920MHz, TD-SCDMA frequency band transmission frequency 2010-2025MHz, CDMA2000 frequency band transmission frequency 2110-2125MHz, WCDMA frequency band transmission frequency 2130-2145MHz, 4G frequency band transmission frequency 2555-2655MHz, WIFI1 frequency band transmission frequency 2400-2483MHz, 5G1 Frequency band transmission frequency 3300-3600MHz, 5G2 frequency band transmission frequency 4700-4900MHz, WIFI2 frequency band transmission frequency 5720-5850MHz.
To
Of course, some people will try to set their mobile phone frequency band outside this range. There are vacant frequency bands such as 2200-2300MHz, but this frequency band does not have the communication signal of the operator, and mobile phone signals installed on this frequency band cannot be used as usual.
Cracking method three
Use WiFi signal: This method has relatively high requirements on the mobile phone and the environment, but on the premise that the mobile phone must have wifi available around the wireless Internet function, the effect is the best and the most secret. Search for available wireless networks through the mobile phone, and after a successful connection, even if the mobile phone has no signal, the information can still be transmitted even if the mobile phone has no signal. This method is invalid. When the mobile phone is within the shielding range of the signal shielding, the mobile phone cannot find the wireless network. In fact, the frequency band of the wireless network will also be shielded. This method is also not feasible. There is also Bluetooth software that is not acceptable, because its frequency will also be blocked by mobile phone jammers. Now that the development of signal shielding is related to the development of communication technology, new communication technologies have emerged, and new signal frequency bands have also appeared. Moreover, since signal jammers are used in places like examination rooms, everyone should abide by the rules of the test. The law of cheating.
