The Research Of Improvement Voice Dropout Rate Using Power Control And Localization Algorithm In The GSM System

This article mainly research change power control parameter to voice dropout rate influence In the GSM System under different scene.Along with our country national economy enhancement , people's expense consciousness also has the earth-shaking change, the user is moving higher and higher the request of the network performance, because of moreover between the different network operator's competition, therefore the people take the network quality more and more quality, The network maintenance's key point pure maintenance of equipment shifts to network optimization that is the top level, if the operator will be in an impregnable position in future development, Takes the bigger market space, the good communication engineering quality is one of successful key aspects. The telephone conversation is the main standard of the network quality, the voice dropout rate reduces means that the conversation promotion, Now as well as change improves the voice dropout rate reason's analysis from handover, the cover angle to discuss, the power control has not been taken to improves primary dropout factor in the GSM system, Opening the power control in the station in initial period, therefore research which is the parameter of control power and the localization algorithm parameter to reduce the dropout rate, the promotion network's retentivity has the noticeable significance in the communication quality under the different environment adjusts in GSM system.The power control is to changes MS or the BTS transmission power with the wireless control mode. Its goal is to reduce overall system's disturbance, raises the frequency spectrum rate, and lengthens MS battery's life. the power control divides into the upward power control and the downward power control. After MS establishes a RR connection, unceasingly report this cell and the neighbor cell measurement result to MSC. BTS surveys the upward signal , these data are saved in BSS. When the processing result indicated handover, the network basis processing result, carries on lining up to the handover candidate cell, MS decides which cell again, the process is called the handover algorithm. The handover algorithm divides into the data processing process, the cell queuing process and the cell decision process, regarding these process's algorithm in the GSM standard, has not given the rigid stipulation, has given a suggestion algorithm in the GSM standard 05.08 appendices, the localization algorithm which Ericsson Corporation uses is merely in BSC decided that the cut condition one kind of software algorithm, the BSC basis survey's information carries on to the periphery cell quite lines up, this is called"Locating"in the handover process. The Locating primary data and serves the cell by the traveling carriage to survey separately then delivers the BSC computation, MS carry on the survey to the downlink, this survey including the current cell and six neighbor cell's downward signal strength and the downward signal quality, will carry on the survey through the SACCH channel transmission for BTS, BTS carry on the up link, this survey report including upward signal strength and signal quality as well as TA value. BSC analysis the survey report which delivers MS and BTS survey report, the information include: MS actual lead, power rank, BA change instruction position, DTX use instruction, downlink Quality, 6 neighbor cell receive level, carrier frequency number, BSIC value. The handset can survey 32 neighbor cell signal, but in reporting for the BTS survey report which most contains 6 cell metrical data. BSC receives the survey report which BTS sends, first carries on the following processing to the survey report: The GSM system establishes a timer for the continual two cut gap (TINIT), to prevent to carry on the cell cut frequently, after each time cuts, must wait for after the timer counts, can carry on the next time cut. Right CELLQ was the HIGH highly quality cell (refers to wireless environment and terrain is quite good, signal quality quite good cell) BSC did not need to do to its report processes immediately, was only carries on the sketchy analysis and processing, right CELLQ was the LOW inferior cell (refers to wireless environment and terrain is complex, signal quality quite bad cell) BSC must do to its report processes immediately, moreover carried on the fine analysis and processing, moreover through establishment parameter MISSNM to reported lost the value made a limit, decided the survey report the precision, if the value were time 2, if lost above 2 survey reports, then front report did not calculate that makes a fresh start to collect. The Locating algorithm makes some mathematical model to many reports processing in certain amount of time, this time is called the filter length, but this model is called the filter model. Through QLENSD, QLENSI, SSLENSD, SSLENSI, TAAVELEN to process the quality, the signal strength, the advance timing, and all kinds of report time lengths to carry on the establishment.We has carried on research the adjustment power control parameter and the localization algorithm parameter experiment separately base on compact district area and the countryside area after three month's in Changchun city, this experiment had proven to use adjustment power control parameter LCOMPDL and HPBSTATE, localization algorithm parameter SSLENSD, QLENSD, TINIT could enable the network the voice dropout rate improvement to achieve above 10%. Through the different time, the place test summarizes under the different scene to suit the network development the parameter disposition, suggests to use the automatic control minute adjustment parameter on OSS, can play the noticeable role to network quality's promotion.