With the signal message in the Gb interface, the theoretical time was got for detecting the doff from network, when MS enters to the blind area and the time for recovering the transmit of data when MS come backs to the coverage.After the comparison between the theoretical values and the actual values, the time about MS being in the blind area, cell reselection, and route updating can be calculated. Thus, the longest interrupt time of the data transmission can be figured. Analyzing the reasons for the set of scheduling command interval and considering the time that blind area can caused, the thesis discusses the unreasonable fact of the interval during data retransmission and brings up a solution to improve it. And then, by using the relevant data of Qinghai-Tibet line, the thesis analyses the feasibility and rationality of this improved solution. The solution can make good utilization of the GPRS channel resources, which ensures the safe and in credible transmission of message.
