Page 146 - ITU Journal Future and evolving technologies – Volume 2 (2021), Issue 2

ITU Journal on Future and Evolving Technologies, Volume 2 (2021), Issue 2

The OPEX cost in T year given:
Scenario 1: Standard case

= ∑(1 − ) −1 ( + + ) + . .
=1
(6)
The TCO of the RAN gives:

= ( + + )(1 + ∑(1 − ) −1 )+
=1
(1 + . )
(7)
Fig. 1 – Standard case of network extension
For the backhaul, we have:
In this case, for network extension, the total cost of own‑
ership for each operator is given by: ℎ = + + (8)
= + ℎ (1) : Annual cost of spectrum
: CAPEX cost of transmitter‑receiver equipment
TCO : Total Cost of Ownership for network : OPEX cost of transmitter‑receiver equipment.
: Total Cost of Ownership for RAN By considering that the OPEX cost of the link is equal to
ℎ : Total Cost of Ownership for backhaul a percentage ω of the CAPEX cost and that according to
the time one notes a reduction of the cost of a coef icient
= + + (2) r’ one obtains the TCO backhaul cost which is given by:

: CAPEX cost of RAN = + . + ∑(1 − ) )
′ −1
: OPEX cost of RAN ℎ =1
: cost of the diffusion spectrum in the RAN
′ −1
Firstly, the cost of the spectrum is neglected be‑ ℎ = (1 + ∑(1 − ) ) + .
cause it is assumed that the operator wishing to extend its =1 (9)
network has at least a national licence to broadcast in the
RAN.
Secondly, for the CAPEX, we consider the cost of the site, −1
the cost of the tower, the cost of the base station itself and = ( + + )(1 + ∑(1 − ) )+
=1
the cost of the electrical infrastructure.
′ −1
(1 + . ) + (1 + ∑(1 − ) ) + .
= + + + (3) =1
(10)
With For n site, we have:
: CAPEX of a site
: CAPEX of a pylon −1
: CAPEX of a base station ( ) = ( + + )(1 + ∑(1 − ) )+
=1
: CAPEX of energy
′ −1
In fact, in one year, the OPEX cost related to the infras‑ (1 + ∑(1 − ) ) . + (1 + . ) . + .
tructure (except energy equipment) can be estimated at =1 (11)
a percentage and, depending on the year, there is a re‑
duction of the OPEX investment by a coef icient r due to The next step is to calculate the cost according to different
the knowledge and mastery of the deployed system. Also, sharing scenarios of interest in the context of rural areas.
the energy OPEX is equal to a percentage of the energy In these scenarios, we consider sharing the infrastructure
CAPEX [23]. Thus, integrating these elements, we obtain: by m operators and deploying n shared sites.
For the irst year:
Scenario 2: Site sharing
1 = .( + + ) + . (4)
In this case, the TCO formula becomes:
Let be: = .( + + ) 1
1
After this year, ( ) = (( ) + + )(1 + ∑(1 − ) −1 )+

=1

= (1 − ). 1 (1 + ∑(1 − ) ) . + (1 + . ) . + .
2
′ −1
2
= (1 − ). 2 = (1 − ) . 1 (5) =1
3
= (1 − ). −1 = (1 − ) −1 . 1 (12)

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