Techno-economic modeling is a simulation-based approach
for developing and optimizing system solutions in different
operator and business environments. It can be extended from
basic cost modeling to business models to produce an
extensive set of financial and technical results. In this case, the
different cost items are linked together. From this data, the
Excel tool calculates the required total expenditure, in terms
of CAPEX and OPEX. It should be noted that the results
presented here are calculated for research purposes only.
The basic structure of a 3G SAE network is quite similar to
a standard WCDMA network. From an architectural
viewpoint, the most important elements of the SAE network
are the base stations, the servers and other entities at the core
site, and the transport network connecting the two [7]. For
modeling purposes, the tool assumes that the base station
network is divided into two parts: the coverage base
transceiver sites (used to provide the necessary coverage over
the model area) and the capacity base transceiver sites (used to
provide the capacity needed due to service usage).
For the coverage BTS sites, the tool assumes 100%
coverage for the urban areas, and a limited (varying) one for
the suburban and rural areas (further details below). The band
for this coverage is assumed to be 900 MHz, with a 5 MHz
band per carrier. The cell range for a single BTS site is either
1.4 km (urban areas), 4.2 km (suburban) or 13 km (rural).
Each coverage BTS costs 25000 euros for the operator. The
main purpose of these sites is to bring 3G LTE available in
every part of the desired area.
For the capacity BTS sites, the tool adds enough 1+1+1
sites to tackle the capacity demand. The band is assumed to be
2100 MHz, with a 10 MHz band per carrier. The capacity sites
are assumed to be placed in the hotspots with the highest
traffic demand. Thus, even though the cell ranges are lower
due to the higher frequency, the only significant factor in
dimensioning is assumed to be the amount of traffic. Each
capacity BTS costs 38000 euros for the operator. Every
capacity BTS site is assumed to cover enough ground so that
its maximum capacity is utilized.
The transport will be divided between Ethernet (900o of all
traffic) and microwave radio (the other 10%). The leased lines
have a capacity of 100 Mbit/s each, whereas the radios offer 8
Mbit/s. The microwave radio is mainly used to provide
transport to outlying sites in the rural areas. The cost of a 100
Mbit/s Ethernet line is 2500 euros per month, while the radios
have a fixed cost of 8600 euros each. These costs are assumed
to decrease 500 per year. The core network is only taken into
account as a fixed cost per each BTS site, since the overall
cost of the core network is very low compared with the base
station network.
The figure below shows the logical structure of the SAE
network in more detail, including the relationship with the
WCDMA network.
techno-economic tool is a simple Excel workbook that
includes all the cost items, all the numerical assumptions
affecting them, and the whole cost structure by which the