Mobile phone detection technology
Mobile phone detection technology mainly detects when the radio wave signal sent by the mobile phone when it is working causes the electromagnetic power in the space where the mobile phone is located to increase to the rated value, thereby determining that a mobile phone is working. This technology sounds very good at first, but in fact it is just a very superficial understanding. When this technology was proposed, the following issues were not considered:
1. Uncertainty in distance between mobile phone and detector (connection loss)
The distance between the mobile phone and the detector and whether there is any resistance in the middle will affect the strength of the signal received by the detector.
2. Cell phone signal strength variability
When the mobile phone is working, which base station actually accesses the Internet is determined by the traffic volume and dynamic configuration of nearby base stations. When the mobile phone is used, if the nearby base station is busy, it will log in to a free base station farther away. The signal strength of the mobile phone will be adjusted accordingly based on the electromagnetic wave loss of the mobile phone to the base station. Generally, mobile phones If the signal received from the base station is strong, the signal strength will be weak.
3． Detector setting sensitivity uncertainty
Generally, the sensitivity settings of detectors do not have an actual quantitative analysis value. During adjustment, dial the signal jammer for cell phone by continuing to adjust the position and observe whether the detector detects the upcoming adjustment sensitivity.
4. Uncertainty in the compressive strength of indoor space interference signals
Common lightning strikes, fluorescent lights, electronic products, etc. are all interference signals. At the same time, the out-of-band spuriousness is very large when mobile phones are working. Although the detector is used to collect the surface acoustic filter on the machine, the filter has insufficient out-of-band suppression and can easily cause crosstalk. When used for detection, other electromagnetic interference cannot be effectively filtered, causing the detection system software to be confused.
5.3G signal detection is difficult
In view of the fact that 3G technology uses excellent technologies such as code division and spread spectrum communication immediate division, and is often engulfed in noise, resulting in smaller signal strength. Especially in mobile 3G technology, the signals sent and received by mobile phones are in the same frequency band and are separated by time. If you are in an area with strong TD signal, the detected declining network signal exceeds the signal transmitted by the mobile phone. Network signals will be difficult to detect and identify.
Therefore, the shielding system using detection technology is extremely serious in false reporting and underreporting, and cannot achieve its purpose of use.
2. Mobile phone detection + blocking technology
The detector controls the power switch of the signal blocker, and immediately turns on the shielding device when a mobile phone application is detected, hoping to achieve the purpose of immediate shielding. However, the reason why the shielding equipment cannot be guaranteed to run immediately in actual operation is that the jammer mainly achieves the shielding effect by preventing the mobile phone from logging into the Internet, and the command sent by the base station to the mobile phone to log in is a gap announcement. If the mobile phone has logged into the Internet , especially if you have already made a call, and the base station does not push the mobile phone to change the original login command, the mobile phone can usually make normal calls. This situation is more obvious in 3G and WCDMA networks. Only when the shielding power can far exceed dozens or even thousands of times of conventional shielding equipment, can the actual effect of immediately interrupting mobile phone communication be achieved. This kind of power is not only difficult to achieve in terms of technology and cost, but its radiation source is powerful and even more unsafe.
3. Current application status of mobile phone signal jammer detection + shielding technology
This type of technology seems to be excellent in terms of its application principles, and is especially recognized and favored by customers in the southeast and northeast regions of my country. However, in fact, no classic cases have occurred so far, and it has caused extraordinary fraud in the industry, giving rise to It has a huge negative impact on the entire field.