Cell phone signal in some areas may be affected by blocking devices

It's time for the annual college entrance examination again. The 2022 national college entrance examination will be held from July 7th to 9th. Good news for customers who have candidates at home! Because during the test, each test center will turn on the high-power signal shielding device, which will affect the wireless network quality of mobile phone users around the test center, such as frequent inability to make or answer calls, intermittent calls, and mobile Internet access. Wait. After the exam, you can return to normal. Please tell the other person.

Although affected by the epidemic, this year's college entrance examination was postponed to July 7-8, but the corresponding measures have not been reduced at all to ensure the security of information in the examination room. Operators have issued announcements one after another that the wireless signal jammer will be turned on during the examination according to the requirements of the Education Bureau, which will affect the communication quality of mobile phone users around the school, and the communication will not return to normal until the end of the examination.

The principle of blocking mobile phone signals

During the working process, the cell phone signal jammer scans from the low frequency band of the forward channel (from the signal tower to the mobile phone channel) to the high frequency band at a certain speed, which forms interference in the process of receiving the message signal by the mobile phone, so that the mobile phone cannot detect the signal from the base station. The normal data sent cannot establish a connection with the base station, showing a state of no signal and no service.

At present, the mobile phone signal blockers used in the examination room are all frequency bands, which can affect all frequency bands of 2G/3G/4G/5G of the three operators, and WIFI signals and Bluetooth signals can also be completely blocked.