Sub- 6 GHz 5G Spectrum for Satellite-Cellular Convergence Broadband Internet Access in Nigeria

Broadband access drives the global digital economy and has triggered the emergence of newer radio access technologies to meet data-driven consumers' expectations. In the period 2019-2025, it is estimated that the compound annual growth rate (CARG) of Sub-Sahara Africa will be above 28 % though ranked lowest amongst other regions. The Covid-19 pandemic has occasioned an unprecedented global demand for broadband internet access. Nigeria's broadband access is 42.02 %, which needs an advanced radio communication network infrastructure upgrade in order to bridge the current gap. Consequently, satellite-cellular convergence is a game-changer for increased rural and urban broadband connectivity penetration. The emergence of the fifth-generation (5G) network is expected to break new market share grounds and increase internet penetration. This paper focuses on the frequency range 1 (FR1: 450 – 7125 MHz) band due to their advantages, including broader coverage, better capacity, and low-cost deployment in sub-Saharan Africa. This paper presents the current usage of Nigeria spectrum bands allocated for mobile communication in the sub-7 GHz band. Potential spectrum bands such as 450-470 MHz, 1427-1518 MHz, 2300-2400 MHz, 3600-4200 MHz, 4400-5000 MHz, 5480-5710 MHz 5900-7125 MHz are suggested to add to the already recommended bands due to their low utilization (i.e., below 10 % average duty cycle). In addition, it is suggested to deploy carrier aggregation methodology to meet gigabit speed for 5G in Nigeria