A Simple and Fast Method for Identification of Missing Adjacencies in WCDMA Networks

The correct identification of pairs of cells to be defined as ´adjacent´ is of key importance in any cellular radio system. However, unlike in other radio access technologies, in Code Division Multiple Access (CDMA) the failure to define a pair of cells as ´adjacent´ can significantly degrade the coverage and capacity of all the cells concerned, especially under conditions of sufficient cell overlap. Current methods to optimise defined ´adjacent´ cell lists are often based on data derived from drive testing. Such approach is not only very expensive and limited to the selected drive routes but, as will be shown later in this paper, it does not necessarily provide accurate results. Methods that utilise purely measurement information from the network normally provide results with a higher degree of accuracy but the application of such methods is relatively time-consuming due to their iterative nature. This paper outlines a simple and quick method to identify missing adjacencies in cellular networks. This method has been used in a commercial WCDMA network and has proven its ability to accurately determine adjacencies that need to be added in order to increase system performance.