Evaluation and Optimisation of 5G Network Deployment Strategies for Metropolitan Areas in South West Nigeria

The rollout of 5G networks in South West Nigeria presents significant planning challenges related to spectrum allocation, site acquisition, backhaul provisioning, and the economics of dense small cell deployment required for millimetre-wave 5G services in high-density urban areas. This study evaluated and optimised 5G deployment strategies for metropolitan areas in Lagos and Ibadan, South West Nigeria. A systems engineering methodology was employed, drawing on operator-provided 4G traffic data, building density maps from geospatial datasets, and 3GPP 5G NR propagation models. Three deployment scenarios were evaluated using the Atoll radio planning tool: macro-only 5G at 3.5 GHz, hybrid macro plus small cell 5G at both 3.5 GHz and 26 GHz, and a neutral host small cell model for the Central Business District. Coverage simulations showed that macro-only deployment at 3.5 GHz achieved 85.3 percent population coverage with a 20 dBm SINR threshold in Lagos, while the hybrid scenario improved to 94.7 percent coverage with significantly higher throughput in dense areas. Backhaul cost modelling revealed that fibre-connected small cells in Lagos Island were 42 percent more cost-effective than microwave backhaul per GB delivered. The neutral host model showed a 28 percent reduction in per-operator capital expenditure when tower infrastructure was shared among three operators. The study recommends the hybrid 3.5 GHz and 26 GHz architecture for Lagos CBD and a macro-dominant 3.5 GHz approach for secondary cities such as Ibadan, with regulatory engagement for neutral host licensing.

Keywords: 5G network deployment, South West Nigeria, radio planning, small cell, spectrum optimisation