The so-called effective shielding refers to whether there are blind spots or missing spots in the shielding effect. Near some prisons, there may be base stations with strong mobile phone signals. In order to achieve a good shielding effect, a lot of materials and energy will be spent correspondingly, and the cost will correspondingly increase substantially. Therefore, the better the shielding effect, the cost will increase accordingly. In actual use, the shielding requirements of the prison area are generally higher, and there are some leaks and blind spots. The offenders may seize this loophole, so that the mobile phone can be used in the originally prescribed shielding area, which cannot achieve the original intention of shielding the mobile phone.
If external interference is not considered, it is relatively easy to simply shield, just increase the shielding power. However, it is necessary to ensure that the shielding area has no blind spots and no leakage points. The power intensity in the shielding area is relatively large. If there is a little leakage, the external interference will be great. This requires full consideration and technical control when cell phone jammer, so as to achieve accurate and efficient shielding without external interference.
