Ranked overlapping coverage based construction of efficient neighboring cell list for GSM/UMTS cellular networks

Abstract

Handover guarantees sustained connectivity during movement of mobile subscribers within cellular networks. In the planning phase of a typical cellular network, the neighboring cell list (NCL) construction depicts the most important feature that would guide the handover performance for each cell. The NCL defines a limited number of cells (neighbors) as candidates for handover from the serving cell of a given subscriber. The identity and number of members of a given NCL play a critical role in the performance of handover where successful handover procedures are mainly attributed to correct construction of NCL. NCLs that suffer from missing neighbor cells result in handover failure or sub-optimal handover decisions. On the other hand, long NCLs are associated with handover delay. In a typical cellular service provider, the initial NCLs are manually constructed and then the defined lists are further optimized during operation. Depending on the efficiency of the manually generated list, the network may suffer bad handover performance until these lists are optimized. To overcome this problem, this paper introduces a mechanism to automatically generate an efficient NCL for a new planned cell based on ranked overlapping coverage using empirical model calculations. The proposed algorithm was tested on a real-life network for two types of mobile generations (GSM and UMTS). The designed NCL is shown to contain all essential neighbors of operationally optimized lists with minimal increase of average NCL lengths.