The Effectiveness of Signal Blockers in Preventing Cheating in Examination Halls

In order to prevent cheating during important admission exams and final exams, Signal Blockers have been installed in various examination halls. These devices are designed to disrupt electronic signals in the vicinity of the exam hall, thereby deterring candidates from engaging in dishonest practices. However, it is important to understand the range of interference that a single Signal Blocker can achieve in a classroom setting. Factors such as signal strength and the proximity of nearby base stations play a crucial role in determining the actual effectiveness of these devices.

Theoretical Range and Practical Considerations:

Signal Blockers have a theoretical interference range of approximately 10-60 meters in an open environment. However, the actual effectiveness of these devices depends on the signal strength at the location, particularly the distance between the jammer and nearby base stations. If there is a base station within 200 meters, interference may prove to be challenging. Additionally, obstacles such as walls can also impact the effectiveness of Signal Blockers.

Classroom Size and Placement:

Typically, classrooms in primary and secondary schools are around 70-80 square meters in size. In such cases, installing a single Signal Blocker in each classroom can yield satisfactory results. These jammers can be mounted on the back wall of the classroom, ensuring that they do not distract students and providing optimal shielding. However, for larger classrooms such as those found in universities with tiered seating, it is recommended to place two jammers, one in the front and one in the back. To ensure effective interference, additional jammers can be installed at regular intervals along the corridors of the teaching building.

Installation Height:

It is important to note that Signal Blockers should be installed at a height of 1.8m-2.5m above the ground. This positioning ensures optimal coverage and interference capabilities.


Signal Blockers have proven to be effective tools in preventing cheating during exams. However, their range of interference is influenced by various factors, including signal strength and the proximity of base stations. By understanding these considerations and strategically placing jammers in classrooms, educational institutions can maintain the integrity of their examinations and promote a fair testing environment.