A representative of the Radio Frequency Department (Ministry of Information and Communications) said that this is a smart fire alarm system with remote warning. Because users bought an unsafe device, it broadcasts 24/7, causing interference with surrounding devices such as smart locks of nearby households.
After 5 days of interference, neighboring households were unable to use the smart keys of their motorbikes and cars, so they contacted the hotline of the Radio Frequency Department to report the source of interference. The Radio Frequency Department of Region 7 went to the scene and discovered that the source of interference was a faulty fire alarm. This fire alarm had been used by the household for 5 years, but had recently developed a fault that caused the interference.
“The fire alarm device discovered in Binh Thuan has a low output power, so it only causes interference within a small range. To detect interference within a small range, we need the cooperation of the people,” said a representative of the Radio Frequency Department.
According to the representative of the Radio Frequency Department, the control devices are in the Wifi frequency range, the frequency band reserved for driving devices... usually only used for a very short time to control the device. However, when it fails, it will continuously emit signals that interfere with other control devices such as smart locks of cars, motorbikes...
Fire alarm equipment is using the 433 Mhz band, which is a common band for devices with conditions. Control devices using this band have technical standards to control the output power so as not to widely affect other control devices. In addition, devices using this band must also comply with regulations on usage time so as not to affect the operation of other control devices.
'These control devices are used for only a short time of microseconds and the small transmission power will not affect other devices, such as car keys, motorbikes or rolling doors. Therefore, in the world, there are still devices using the same frequency band in medicine, scientific research, and low-power control devices can still coexist. For example, a faulty smart lock device and continuous transmission will affect the smart lock devices of cars and motorbikes in the nearby area, but if it is not faulty, the surrounding devices will still operate normally. Previously, in Dong Tam ward, Hanoi, there was a faulty water pump control device that also continuously transmitted, causing interference to cars and motorbikes in that area and unable to use the smart lock,' said a representative of the Frequency Department.
Recently, according to the reflection of people in the area of the intersection of Vong - Nguyen An Ninh Street, Hanoi, within a radius of about 100m, a strange phenomenon occurred when many vehicles and devices such as rolling doors, motorbikes, and cars controlled by smartkeys could not operate. The Frequency Department later discovered that the remote control device to control the water pump was causing signal interference here.
The representative of the Regional Radio Frequency Center I also said that the above-mentioned interference device has unknown origin, no certification stamp, and has emission quality that does not meet the regulations on the frequency of 433.9 MHz/bandwidth of 37.5Khz. Therefore, it caused harmful interference on the frequency band for remote control devices to open and close car doors, lock motorbikes, etc. (433.05-434.79MHz) in the surrounding area. Afterwards, the working group of the Regional Radio Frequency Center I (Radio Frequency Department) together with PA06 and Dong Tam Ward Police handled and seized this device.
The representative of the Regional Radio Frequency Center 1 also said that the Radio Frequency Department has set up a hotline number 0862.92.92.92 to receive feedback from organizations and individuals when detecting smart car and motorbike locking devices and other cases of radio interference.
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