Wireless signal jammers have become "standard" products in various examination rooms and conferences, whether it is high school entrance examinations, postgraduate entrance examinations, CET-4 or CET-6, civil service examinations and various professional examinations. In order to ensure the fairness and justice of the examination, wireless signals are shielded and passed through electronic products. To isolate cheaters, blockers will be used!
Wireless signal jammers are known by many different names, such as signal jammers and signal isolators. For the uplink and downlink channels of the mobile phone system, technologies such as frequency multiplication, frequency division, and frequency hopping filtering are used to analyze the required shielding frequency. A spherical shielding space is customized according to the power of the shielding device, and a shielding magnetic field is automatically formed within the specified range, making mobile phone signals in this space ineffective. When the shielding device is in working condition, the function of sending and receiving signals by mobile phones within the specified range can be disabled, and neither outgoing nor incoming calls can be made, thereby achieving the purpose of forced disabling.
There are currently many suppliers of wireless signal jammers, and their products are also diverse. The following points are usually considered when purchasing:
1. Appearance
Compared to the shielder, it is not particularly important, but the structure of the shielder is different. From the appearance, the shield can be divided into external antenna and internal antenna. The antenna and power supply of the built-in antenna are installed in the casing, occupying a small area. It is convenient to connect the antenna before use, so the first choice for mobile phone signal shielding in the examination room is built-in antenna signal shielding. In addition, the appearance of the jammer also needs to consider the visual experience of the candidates. Try to keep the appearance simple and the colors unobtrusive to avoid visual stress on the candidates.
2. Power
Generally divided into low power, medium power, and high power. Except for special occasions, it is generally not recommended to use high-power signal shielding equipment. This will seriously interfere with the signal transmission of the base station and cause certain radiation to the human body. For example, for educational examinations, standardized examination rooms, and conference rooms, it is recommended to use low-power ones. Even if a low-power one is not effective in some places, multiple cellular distribution points can be selected. This effect is better than using a single medium or high power, and the radiation is not as large.
3. Power supply method
Power supply, handheld built-in lithium battery, easy to carry. After the power is used up, use the charger to charge; 20V power supply, the desktop used in the examination room is powered by 220V voltage.
4. Frequency requirements
Before purchasing, you need to know which signals you want to block. Normally blocked mobile phone signals are (2345G and 2.4G).
5. Shielding effect
This is an important point when choosing a wireless signal jammer, but it is also a point that is easily overlooked. Why is it easily overlooked? Nowadays, many manufacturers forcefully recommend a certain signal jammer without understanding the signal environment and range of the examination room. This can easily lead to poor shielding effect and the inability to completely block wireless signals. Therefore, when looking for a manufacturer to purchase a mobile phone signal jammer, you should conduct on-site testing in order to customize a shielding solution suitable for the examination room environment.