Testing the Shielding Effectiveness of Portable Interference Devices Using Multiple Mobile Phones

A Convenient and Feasible Method for Assessing Interference Radius

The effectiveness of portable interference devices can be tested using multiple mobile phones operating on various frequency bands. This method offers convenience, efficiency, and practicality compared to the limitations of testing software on smartphones or the need for conversion after using professional instruments. By following a simple procedure, users can easily assess the shielding effectiveness of portable interference devices.


  1. Prepare multiple mobile phones operating on different frequency bands, including Mobile, Unicom, Telecom 2G/3G/4G/5G.
  2. Hold each mobile phone and test the effective interference radius of the portable interference device from the nearest to the farthest installation position.
  3. It is recommended to test the interference distance from multiple directions simultaneously during the testing process.
  4. The portable interference device utilizes an omnidirectional antenna, providing the best coverage in a circular pattern. For example, when testing in a prison corridor, align the device towards the doors or windows of the cells and test the interference effect by placing a mobile phone inside the cell.
  5. To determine if a mobile phone is being interfered with, it is important not to rely solely on the signal bars displayed on the phone. Signal bars can sometimes be misleading. Instead, intermittently make calls using the mobile phone, attempting to dial a local toll-free number or a fixed landline number. If the call cannot be connected, it indicates that the phone is still within the interference range. Conversely, if the call is successful, it means that the interference range has been exceeded.
  6. To test if a specific location is within the interference range, hold the mobile phone in that position for at least 30 seconds to confirm if it is being interfered with by the portable interference device.
  7. To check if internet connectivity is being interfered with, reopen web pages that were not previously accessed (as cached pages may not reflect the current status) and log in again. If successful, it indicates that there is no interference.
  8. Mobile phones have inherent resistance to interference, which allows them to adjust their transmission power to ensure uninterrupted communication. Therefore, it is generally recommended to conduct static testing at various locations rather than dynamic testing during active calls.
  9. Record the distance of the interference radius for each frequency band after testing and use this information to determine the effective interference radius of the portable interference device in the area.


Testing the shielding effectiveness of portable interference devices using multiple mobile phones operating on different frequency bands provides a convenient and feasible method. By following the outlined procedure, users can accurately assess the interference radius of the device. This approach offers simplicity, efficiency, and practicality, making it the preferred choice for users.