# Transitioning to Society 5.0 in Africa: Tools to Support ICT Infrastructure Sharing
## 2 Background and Related Work
### Benefits and Costs of Infrastructure Sharing  
Several scholars have made initial contributions to improving the Nigerian telecommunication infrastructure system through colocation of BTSs and infrastructure sharing; however, there is no proposed method or design for how to successfully achieve this. The issue of which sites, BTSs or masts to select as the host for colocation still poses significant hindrances and challenges for the telecommunication industry [4]. Current research in the area follows a top-down approach considering the work of [PERSON] et al. (2015); [PERSON] et al. (2013) and [PERSON], [PERSON] and [PERSON] (2011) does not convince the telecoms industry that the benefits of mast colocation outweigh what they see as the potential negative impacts of mast colocation on their bottom line/profits. In contrast, the method suggested in this paper uses a bottom-up approach to illustrate the economic and environmental benefits of mast colocation to the telecoms industry using real world cases of current mastlocations in an area to demonstrate the benefits. Telecommunication infrastructure sharing played a significant role in checking the growth of mast erection. In the UK most of the infrastructures are shared to reduce the number of sites and mast erection, it reduce site acquisition times for new entrants, provide easy access to places of strategic importance where space for new sites is limited, reduce capital expenditure and operating expenditure, reduce environmental health issues as outlined by some scholars and reduce visual impact. This also helps to increase service coverage [4; 5]. There are two main types of infrastructure sharing: passive and active sharing, as shown in Table 1 and summarized below. Passive sharing involves the sharing of spaces and physical infrastructures that support telecommunication but does not play an active role in the operational network coordination, and good examples are site, mast and RAN sharing. In site sharing, mobile operators share the same compound but have separate installations such as masts, cabinets, backhaul equipment and antennas. Mast sharing involves mobile operators using the same mast, and each operator antenna is mounted on the mast. Active sharing, however, involves the sharing of some elements in the radio for operational coordination, which is usually performed by configuration of the radio network. This includes core network sharing, which involves the sharing of transmission node, switching center, billing platform and the network logical entities with another mobile operator. Normally, all these elements listed have up to two or more spares that can be leased out, but they are all logically separated. Network roaming is another form of active infrastructural sharing whereby a mobile subscriber is carried along or rides on another mobile operator network. Types of network roaming include national, international and inter-system [5]. Infrastructure sharing, if implemented correctly, can potentially enhance the improvement of service quality rendering to mobile telecommunication network subscribers, as identified in [16]. Many subscribers complain about poor services, and the initial stage of the research has identified that the quality of service offered by mobile operators in the country is unreliable [17; 18; 19; 20; 21]. Many GSM subscribers in Nigeria have been complaining about the incessant substandard services rendered by mobile telecommunication operators in Nigeria [19; 20; 21] and have experienced call drops, network congestion, crosstalk, occasional service outages and delays in short message service (SMS). Call drops, network congestion and others network problems are experienced because of poor received signal strength and poor energy per chip to interference energy ratio (Ec/lo). The quality-of-service challenges in the Nigerian telecommunication sector today exist due to the inability to expand and optimize the network as users increase with different real-time applications.