Assessment of Network Handover Performance in Heterogeneous Mobile Networks in Calabar

Network handover mechanisms are fundamental to maintaining seamless mobile communication as users move between coverage areas of different base stations or different radio access technology layers in heterogeneous network environments. This study assesses handover performance in heterogeneous mobile networks covering the Calabar metropolitan area in Cross River State, South South Nigeria. Drive tests were conducted along sixteen road transects covering diverse urban environments including the university district, the waterfront commercial zone, and residential areas, using network testing devices and specialized software to log handover events, signal strength transitions, and call continuity across 4G, 3G, and 2G network layers. A total of 2,340 handover events were captured and analyzed. Results indicate an inter-RAT handover failure rate of 11.4% for transitions from LTE to 3G, with the majority of failures occurring in transitional zones between the urban core and peri-urban areas where LTE coverage is inconsistent. Intra-LTE handover performance was substantially better, with a failure rate of 3.8%. Handover failure was strongly associated with inadequate LTE neighbor cell planning and excessive handover thresholds configured by network engineers. The study recommends optimization of handover parameters through automated SON solutions, targeted LTE coverage extension at identified gap locations, and antenna configuration reviews at five high-failure base station sites identified during drive testing. Keywords: handover performance, heterogeneous network, LTE, drive test, Calabar.