The Study On The Solutions For Blocking Problems Of Radio Cells In GSM Mobile Communication System

The blocking problems of radio channels in Global System For Mobile Communication(GSM) mobile communication system have badly restricted service expansion for mobile service provider due to the increasing subscriber number, the reducing network construction investments, and the advancing customers requirements for quality of service (QoS). The effect by use of single means to handle blocking problems of radio channels in GSM mobile communication systems is not in evidence under the actual communication environment. It is the common responsibility for mobile telecommunication services operator and telecommunication equipments provider to improve the mobile communication systems by means of adopting the combining technological strategies, and to evaluate the advantage of such combining technological strategies.Firstly, the system of GSM beehive-network and the technique of network constuction are introduced simply in this paper, which includes the constuction of GSM system,the distribution of frequency and the structure of GSM beehive-network.And then, the reasons of bringing the block in some radio channels, such as Traffic Channe(TCH) and Stand-alone Dedicated Control Channel(SDCCH), are analyzed in detail. Starting with the radio waves transmission and the princple of the mobile networks planning, the engineering optimizing methods with the combination of adjusting antenna and configuring the cell parameter for handling the blocking problems in radio channels are induced systematically. The techniques such as Dual Frequency Network, Subdistrict Split, Tiny-beehive and more tight frequency multiplexing, which improve the wireless network capability and the capability of GSM net work., are introduced.Finally, the two kinds of the solution measures of congestion are presented mainly. 1) the voice traffic can be balanced by adjusting some parameters, thus the congest phenomenon in some weak signaled subdistrict are sloved.2)The half rate speech project . The analysis of the advantages of half rate speech which can increase the capability of network and its disadvantages on the quality of communication is given, and through testing on some subdistricts by the half rate speech projet and evaluating on the capability parameters which gain in the test, the feasibility of half rate speech, which present some essential additions to slove the network congestion, is proved. In 2006, an optimal engineering was put in practice in the GSM mobile network of Wuhan city while the author was just a trainee in HuBei unicom . During the period, many projects foroptimizing the radio channels, such as antenna adjusting, cell selecting, etc, were brought in effect. After so doing, the performances of radio channels are greatly improved. And with the help of colleagues, the author has gained precious test-data and practice experience.