The SEMS of the Syrdarya region received an application from one of the mobile operators about external interference. Determining the causes of interference in a mobile communication network is the process of identifying factors that cause interference between radio signals, which leads to a deterioration in communication quality, a decrease in data transfer rate, an increase in errors, and even a temporary denial of service to subscribers. It includes technical analysis of network parameters, monitoring of the radio frequency spectrum and direction finding of possible sources of interference.
The work on identifying the probable source of the radio interference was carried out in several stages:
At the initial stage, employees of the SES of the Syrdarya region, together with specialists from the mobile operator, conducted a detailed technical analysis of the operation of base stations (azimuths and tilt angles of sector antennas) exposed to external interference. Data analysis makes it possible to identify priority areas for the departure of mobile radio monitoring complexes and effectively organize their work. A targeted survey of a pre-determined area increases the efficiency of resource use, makes it possible to locate the source of interference faster and reduce the time to eliminate violations.
Determination of the intended search area (direction). Based on the results of the analysis, the territory (direction) where it is necessary to carry out radio monitoring activities was determined. Based on a preliminary analysis of radio interference parameters such as frequency, signal strength, time characteristics, and radio monitoring data, the estimated area or direction where the source of interference is most likely to be located is determined. Narrowing down the search area and identifying priority monitoring areas is necessary to ensure more accurate route planning for the mobile radio monitoring group.
Departure to the location of the probable source of radio interference. Further, the staff of the SAMS of the Syrdarya region conducted a visit to the place of the probable location of the source of radio interference and organized radio monitoring activities using the available means of radio monitoring. Radio interference can be complex and variable, and only when traveling directly to the intended location can the coordinates of the source be clarified using mobile direction finders and other wearable measuring devices. It is possible to determine the type of interference on site (intentional, unintentional, continuous, etc.) and identify the technical means (equipment) that create it (for example, a faulty power supply, a faulty radio station, a household appliance, etc.). Only on site can local features of the terrain and buildings be taken into account, as well as the state of actual congestion of the radio frequency spectrum, which may affect the characteristics of radio interference.
Organization of radio monitoring. Radio monitoring was aimed at searching for constant carrier signals in the radio, as well as broadband noise and interference in the frequency range of the mobile network. Technical measurements were carried out using the direction finding equipment of a mobile radio monitoring station, as well as the directional antenna of a portable measuring device. Azimuths for the probable source of radio interference were determined at several measurement points, as the intersection of the azimuths will help determine the exact location. According to the results of the direction finding, a continuous (constant) broadband signal in the frequency range of the mobile communication network was recorded on the radio. Further, a visual inspection and survey of objects based on the results of direction finding (residential buildings, offices, technical premises) for the installation of external antennas was carried out. As a result of the organizational and technical measures taken to find the source of radio interference, mobile signal amplifiers (repeaters) in the amount of 3 sets installed next to residential premises on the territory of a legal entity were identified.
Eliminating the source of radio interference. Based on the results of the radio monitoring, information on the use of mobile signal amplifiers (repeaters) that negatively affect mobile networks was transmitted to the Territorial Office of the Uzkomnazorat Inspectorate for the Syrdarya region and law enforcement agencies. Based on the operational measures taken, the operation of mobile signal amplifiers (repeaters) in the amount of 3 sets was discontinued (the antennas were dismantled), and the owner was given a written injunction prohibiting the further use of these distribution zones.
In accordance with the decision of the Republican Council on Radio Frequencies No. 707 dated August 23, 2022, the development, modernization, production and import, as well as the use of relay devices that amplify mobile network signals that do not meet technical conditions, are strictly prohibited in the territory of the Republic of Uzbekistan. Repeater users should take all necessary organizational and technical measures to prevent radio interference from their devices to the networks of mobile operators.
Prepared by: Engineer of the 1st category of the SEMS of the Syrdarya region Raimdzhanov Zh.S.
