The high temperature weather in Hangzhou, because of the interference of atmospheric waveguide, leads to the influence of mobile phone signal. What is an atmospheric waveguide?

Cell phone signals propagate in the air in the form of electromagnetic waves. When a mobile phone makes a call, it will convert the voice into a signal and then send it to the nearest base station A in the form of electromagnetic waves. After receiving the signal, the antenna of base station A will gather and transmit it to the network equipment through wireless equipment, and then gather it to the switch and forward it to base station B, which will send the signal to the other party's mobile phone. After receiving the signal, the mobile phone will convert the signal into voice, thus realizing the conversation between the two parties. Communication between mobile phone and base station antenna is the key. As mentioned above, the waveguide mainly interferes with the signal between your mobile phone and the base station.

Atmospheric waveguide is very sensitive to the change of atmospheric humidity, especially evaporation waveguide. It is more serious in a stable, windless and sunny environment; The lower the vertical temperature difference, the more serious the situation. The influence of meteorological conditions on atmospheric waveguides is too long to read: Ningbo and Hangzhou, two coastal cities, are prone to atmospheric waveguides that affect communication because of humidity and temperature difference; Therefore, "the high temperature causes the mobile phone signal to be affected, which is not rigorous, stable, sunny, windless and the vertical temperature difference is small", which is the reason that causes the atmospheric waveguide to be serious and indirectly affects the signal. For inland cities, the high temperature affects the new mobile phone number. More reasons are that the base station power supply system starts or the high temperature causes the base station equipment to start.

Atmospheric waveguide is an abnormal atmospheric structure that forms capture refraction in troposphere environment. It has the characteristics of long horizontal scale and obvious weather background, which is mainly caused by the inversion of temperature and humidity in the atmosphere, that is, the water vapor density decreases rapidly with the increase of height, and the temperature increases with the increase of height. The main weather processes conducive to the formation of atmospheric waveguide include: sea surface evaporation, high pressure sinking, frontal process, nighttime radiation inversion and advection.

When the atmospheric waveguide appears, the propagation trajectory of electromagnetic wave in the near-surface layer bends to the ground due to atmospheric refraction. When the curvature exceeds the curvature of the earth's surface, electromagnetic waves will be partially trapped in a certain thickness of atmospheric thin layer (that is, waveguide layer), just like electromagnetic waves propagating in a flat dielectric waveguide. This trapped refraction propagation phenomenon of electromagnetic waves is called atmospheric waveguide propagation. The existence of atmospheric waveguide environment changes the propagation path and range of electromagnetic waves, resulting in some special propagation characteristics in communication, detection and navigation systems, such as radar over-the-horizon propagation and detection blind spots. In order to make full use of and effectively avoid the atmospheric waveguide effect, scientists have done a lot of research.

Influence and application of atmospheric waveguide phenomenon;

1. The influence of atmospheric duct phenomenon on secondary radar is one of the basic components of air traffic control system. It sends and emits inquiry signals to the target, and the airborne transponder sends back the reply signal after receiving the inquiry signal, and the secondary radar receives the reply signal to detect and identify the target. In practical use, the secondary radar is not easily disturbed by weather and ground objects, but the atmospheric waveguide phenomenon that often appears in coastal areas will greatly increase the range of the secondary radar. If not handled properly, it will not only increase the detection range, but also interfere with the monitoring of normal targets.

2. Influence of atmospheric waveguide phenomenon on shipborne electronic information system.

Atmospheric waveguide phenomenon is the most common phenomenon in marine environment, which can negatively refract electromagnetic waves. Electromagnetic waves propagate in an atmospheric waveguide layer with a certain thickness. Except for short wave communication, other communication frequencies of shipborne electronic information system are above high frequency band. Atmospheric waveguide has an important influence on the propagation of shipborne electronic information system.

Atmospheric waveguide can be applied to communication countermeasures.

Maritime communication signals are dense. High and complex characteristics, especially in the atmospheric waveguide environment, the over-the-horizon propagation of electromagnetic waves increases the effective communication distance and the probability of exposing the target, especially when the ship chooses covert action. If there is an atmospheric waveguide on the sea surface, the selected communication parameters can achieve over-the-horizon communication, but can not achieve the purpose of concealment. Therefore, if the atmospheric waveguide phenomenon is encountered in the silent anti-reconnaissance at sea, the parameters that cannot be used for over-the-horizon communication should be selected according to the requirements of over-the-horizon transmission of atmospheric waveguide. Although the atmospheric waveguide has a certain influence on human activities, as long as it is studied more, it is believed that it will become a good helper for the development of human civilization in the near future.

The uplink interference of atmospheric waveguide to wireless signals is relatively large. The engineer of Hangzhou Branch of China Telecom said that the transmission loss of wireless signals in the atmospheric waveguide is very small, and the downlink signal of the far-end base station falls into the uplink receiving window of the near-end base station after a long distance of several hundred kilometers, causing uplink interference. "For users, the most direct feeling is that the network speed is not good.

At present, the atmospheric waveguide mainly occurs in the inland suburbs or coastal areas at the turn of spring, summer and autumn in winter, and the impact generally occurs above 100 km. For operators, it is nothing new that Hangzhou is interfered by atmospheric waveguide. By modifying the time division ratio of special sub-frames, Hangzhou Telecom's network performance is obviously improved, the subsequent far-end interference sources are weakened, and the number of interfered cells is obviously reduced. "We have to monitor the impact of the atmospheric waveguide every day, but this year Hangzhou encountered extreme high temperature days, and the impact suddenly became greater.

Under normal circumstances, it takes about 1 hour after the adjustment is successful, so as to minimize the negative impact of high temperature on the signal. "In addition to the cell phone signal, there are street signs affected by the high temperature weather in Hangzhou. The continuous high temperature in Hangzhou, in the area without shade near the West Lake, the garbage classification signs on the shell boxes were sunburned and began to fall off. At present, sanitation and cleaning personnel are trying to avoid the high temperature, but people come and go by the West Lake. They inspected the road surface in groups and carried out environmental improvement. Colored garbage, mineral water bottles and shell boxes in the green belt. Waiting is the category they clean up. Not only the garbage sorting boxes, but also the road brand names of some roads in Hangzhou have been damaged by high temperature. " The green paint on some road brand names has been sunburned. "Xu Cijing of the Inspection Section of the Gongcheng Urban Management Municipal Facilities Security Center in Hangzhou told the reporter.

There is basically no shelter around these road signs damaged by the sun, and most of them are directly exposed to the sun. Road name plates are made in accordance with the specification requirements, made of stainless steel, sprayed with special paint, and can reflect light at night, so that drivers and passers-by can see clearly. At present, the municipal department of Yegong Urban Management has conducted a general survey of road brand names of more than 80 main roads in the whole region. Once the municipal inspectors find blisters, wrinkles and paint drops on the surface, including crooked, loose and unclean road nameplates, they will replace them.