Research On The Detection/Identification Of The GSM Pseudo Base-Station

Pseudo base-station is a kind of radio transmitter/receiver that disguises as the true public mobile communication base-station. It will catch or exchanges information with the regular mobile-terminal. Pseudo base station illegally occupies the spectrum resources, sending a large number of unwanted and fraudulent messages. This has caused a serious impact on the people’s normal life and becomes one of the hot issues of social concern. Pseudo base-station and the normal base-station work at the same frequency point, which is very difficult to identify them by regular methods. Even near the "cover" region, we find that it is very difficult to detect and identify the pseudo base-station due to the complex surrounding environments and the uncertainty-frequency.In the paper, we will design the rapid detection/identification schemes based on the hardware and software characteristics of the pseudo base-station. The main contents of this paper include:1) The pre-analysis of hardware system, including hardware architecture and component object detection function, dismantling/analysis of hardware components, searching the corresponding breakthrough points;2) The pre-analysis of software system, including software architecture, the relative parameters setting and the data-processing procedure, searching the corresponding breakthrough points;3) We have presented a rapid detection/identification scheme based on the C2 value of the engineering testing terminal. The scheme will catch the frequency point by the abnormal C2 value, then lock the suspicious frequency points for monitoring of some parameters, including power level, C1 value, LAC value, CID value, et al. The detection/identification will be performed jointly based on these multiple parameters.4)We have further presented a rapid detection/identification scheme based on the decoder of the base-station. The scheme will catch the related information of different telecommunication companies and their frequency parameters of the base-stations (such as CID, LAC, et al). Then we will calculate the C2L value based on the power level and C2 value. Using multi parameter detection of pseudo base, then lock suspicious frequency, decoding the location update number recognition to confirm whether the pseudo base-station. Different telecommunication companies will have different base-station parameters, which leads to different regions of the C2L value. Based on this fact, the scheme must adjust the relative thresholds and the detecting rules.5) We have set up the actual hardware simulation platform to verify the rationality and feasibility of the presented schemes based on single pseudo base-station, multiple-parameters, multiple signal-emissions. We have performed a lot of simulation experiments in specific testing environments and obtain the corresponding simulation data to finish the related statistics and comparison works.In this paper, we have performed 128 groups data of two different simulations with respect to the two presented detection/identification schemes, respectively. In practice, the C2 value in scheme 1 may be influenced by the distance, fading, power and other factors, hence its threshold may have a large fluctuation, which will influence the success rate of the detection/identification. For the scheme 2, we have considered multiple parameters, including CID value, LAC value,C2 value, the power level and other parameters. It is not surprise that this will improve the success rate of the detection/identification. Simulation results show that the two presented schemes both can work effectively. The success rate of the scheme is 87.5% and the success rate of scheme 2 is 95.3%. It can be seen that, the simulation results are consistent with the theoretical analysis of the paper.