Three Kinds Of Automatic Frequency Optimization Method Comparison Study

Mobile phone users and voice traffic have achieved significant growth over the years and the mobile network quality demands from the network user's perspective have been gradually reaching to the highest standard. With increasingly fierce competition and sky-high customer expectations, mobile operators around the world are striving to extract every last bit of performance and value from one of the biggest assets, the Frequency Planning. Thus, the use of the manual frequency planning method for mobile network has proved to be short in meeting the higher quality demands of the more complex large-scale mobile network. Currently frequency planning has been shifted to Automated Frequency Planning (AFP) from the conventional manual frequency planning. The AFP projection based on propagation model has now developed into complex yet efficient algorithm based on real-life inter-cell interference level thus deliver significant savings on both network infrastructure investments and precious engineering time. The AFP methodology is generally based on three projection methods:(i) Network Measurement Reports, (ii) Frequency Scanning Data and (iii) Inter-Cell Handover Data. This article compared these AFP methods based on theory, operation processes and optimization results.This article achieved the following four aspects of the research work:1. Brief introduction on the history of the development of mobile communications services and summaries the past and present development of the frequency planning research. Introduction and commentary on the development and the latest progress of the AFP have also been made.2. It outlines the ways and means of data collection by the three modes of AFP, and introduces data processing method with the data collected respectively. It also makes detailed analysis on the construction of automated frequency interference matrix and the sub-frequency algorithm based on interference matrix of all three different modes.3. It outlines the operation progress of all three modes of AFP software. Comparisons and reviews of the software were made based on the data required, workload,.4. Actual tests of the three modes of AFP were conducted in December 2008 to May 2009 by Zhejiang Mobile (ZJMCC) at Hangzhou, Shaoxing and Taizhou. The optimization effectiveness are compared with the related key performance index such as Traffic, Dropped call rate, Handover success rate, Downlink and Uplink Quality, GSM and EGPRS drive test. The end results have shown the method based on Measurement Report is generally the best out of the three. Meanwhile the frequency scanning method has returned better result for the drive test. The automated frequency based on handover data falls short generally and needs to be further improved.