1. The application of signal blocker device should be avoided by the crowd to prevent the crowd's mobile phone signals from being affected.

Among the customers who use portable signal jammers, some are to prevent cheating in the examination room, and some are to create a quiet environment without electronic communication disturbance in the main venue. This is to create a quiet environment in special occasions. In fact, some people are for their own interests. For example, if they operate businesses in public telephone halls, they will make full use of the shielding network they undertake to affect their business locations such as nearby mobile communication base stations and installed signal amplifiers, so that the staff around the public telephone booths they operate will find it difficult to use mobile phones, but will change their source of income to voice calls in public telephone booths. In addition, mobile communication network operators may also use portable signal jammers to harm the interests of the other party, so that they can gain advantages in some local competition. In addition, portable signal jammers are also very easy to be added with mobile phone software, becoming a veritable eavesdropper.

In fact, according to scientific research, it is possible to use portable signal jammers without affecting the normal start of public mobile communications. There are three reasons for the data signal of mobile communication base stations:

First, the users of portable signal jammers do not consider the communication needs of smiling people at all, and the functional objects are wrong. They should limit the mobile phone communication of a small number of people (such as students), but they expand the target to other ordinary groups nearby.

Second, the operation method is unreasonable. Because the portable signal jammer is placed in an unreasonable place or its transmission power is set too large, it should be operated in a local area but it is not operated well.

Third, the purchased portable signal jammer does not meet the approval specifications of radio equipment, the output power exceeds the standard, or it is a counterfeit and unqualified product. Find out the reason. In order to get rid of the power hazard of mobile communication signals, it is actually very simple: first, use reliable manufacturers to produce qualified products, then choose the installation location and direction of the effect direction, set a moderate transmission power, and limit its transmission signal to a closed local area. If the above three points can be achieved, the impact on the surrounding mobile communication base stations can be minimized.

2. The unreasonable use of portable signal jammers in colleges and universities may cause unnecessary damage to the body.

Theoretical analysis shows that when the portable signal jammer is working, if the setting is unreasonable and the transmission power is too high, in a closed space such as a local conference hall or classroom, the radio waves accumulate in a small space, and are reflected by the walls, ceilings, and floors that are separated from the outside, which will put the people in the room in a serious electromagnetic radiation. According to the survey, the college entrance examination and the high school entrance examination are the places where the portable signal jammer is used the most. In some examination venues where the jammer is used, some of the defendants (college entrance examination inspection staff, students and teachers) are upset and unable to concentrate, and some students even have headaches. Various signs show that if the transmission power of the backpack jammer is too high, it will affect the normal thinking of the candidates in the examination room. As we all know, the characteristics of electromagnetic waves that are transmitted freely in the air, while the portable signal jammer promotes the isolation of the mobile communication base station data signal in a specific area and achieves its limited purpose, it will also damage health to varying degrees, so the portable cell phone jammer must be used with caution.