TECHNOECONOMICS OF DIMENSIONING

As already stated several times, the business plan and the dimensioning strategy are the main factors that affect the network size and overall investment. On top of the access network, a backhaul network should be implemented to connect the access with the core network, and there is also the core network infrastructure. The overall equipment depends on the number of PoP, almost in a linear manner. Further to the equipment costs, the deployment engineering costs should be also taken into consideration.

COST INCREASING FACTORS DURING DIMENSIONING

The dimensioning output may lead to an oversized/undersized network mainly for two reasons: either due to the business plan or due to a low quality study. In the first case it is the responsibility of the author of the business plan if it is not so realistic, while in the second case it is the responsibity of the designer if a study outcome is of low accuracy. The main parameters that impact the network size and hence the costs can be seen in Table 1. An ambitious business plan will most likely lead to a significant investment. However, in terms of network design and implementation, a huge network increases design complexity which results in longer time-to-market. A scalable deployment is preferable since a higher design quality can be obtained. In contrast, lack of scalability would further extend the transition period until the network implementation is finalized. The costs and complexity also depend on the number of PoP. If the distance between PoP is very small (i.e., less than 0.5 km) then the design complexity is increased significantly. For capacity-limited networks that require too many sectors it would be cost effective to use higher sectorization per BS or a dual sector layer if possible. Finally it should be mentioned that for areas under heavy construction the expected terrain changes should be considered since they may result in a long design and implementation period. Any condition that would result in longer engineering times (design, implementation) would also further increase costs. Furthermore, terrain changes may alter the coverage and hence a revision may be necessary after a period.

Table 1: Dimensioning Size and Cost Increasing Factors 

Factor	CapEX/OpEX	Complexity	Time-to-Market
Ambitious business plan	Very high	Very high	Very long
Unbalanced number of PoP	High	High	Long
Luck of scalability strategy	High	Very high	Long transition
Environmental changes	High	High	Long transition