Page 108 - ITU Journal Future and evolving technologies Volume 2 (2021), Issue 5 – Internet of Everything

ITU Journal on Future and Evolving Technologies, Volume 2 (2021), Issue 5

TI represents the total investment in the same The formula is updated as follows:
network cluster or in the same geographical region.
Since the VUPU price is time dependent, price is ( ) VUPU =
=180( +1)
updated with the following formula: ∑ =1 ( . (∑ =180 ( , . )))+max { ,0} . (7)

1
( ) VUPU = (1 − ) ( − ) VUPU + 2.2.3 Subscriber Unique Permanent Identifier

1
( ) ( ) VUPU (5) (SUPI) Factor (SUF)

where C is the constant used to update the price. means the number of different SUPIs (5G),

With lower C values, a recent calculated price has IMSIs (4G) that are recorded by base station n. It is
more impact on the average price, and vice versa. defined as follows:
With a newly deployed network cluster, big C values = + log( ). (8)

are selected in order to converge to a certain price.
If = 1, this means the same users connect to the

2.2.2 Mobile device diversity factor same base station n. For modeling the SUPI factor,
any logaritmic function can be used. The reason for
A base station serves different types of terminals
depending on the time and location. A more diverse using the logarithmic function is that the increasing
set of terminals increases the value of the base number of diversity in the network will have lower
station, and augments the value of theVUPU. The impact on the value since the base station will be
following formula is used to summarize the impact overloaded after some point leading the total
of terminal diversity: service quality degradation for all terminals
connected to the base station. In a commercial
1
= 1 + ∑ ( ) (6) network, user capacity per base station ranges
=2

between 600 and 1200 connected users for 5G base
where is the device diversity factor of base stations. And, with SUF = 1, there are 600 different

station n, TT is number of different traffic types SUPIs recorded by the base station. If SUF = 2, this
served by the base station in a 24-hr window. For means there are 1200 unique SUPIs recorded by the
example, if the base station serves only one traffic base station. With SUF, the new formula for the
type, = 1; and if the base station serves one price of VUPU will be

different traffic type in addition to mobile traffic,
then = 1 + 0.5 = 1.5. Fig. 7 shows DDF values ( ) VUPU

corresponding to different traffic types. ∑ ( . . (∑ =180( +1) ( . )))

=1

,
=180
= 1
( )
.
max { ,0}
+ 1 . (9)
( )
.
The DDF value curve can have any shape depending
on the number of hand-offs. Fig. 8 shows the DDF of
a base station serving both mobile and nomadic
users. Since subscribers/users are mobile,
subscribers/users will hand off from one base
station to another base station during the day.
When users are stationary or nomadic, depending
on the location of the user, Wifi might be available.
Thus, users will use Wifi connection especially on
these occasions. This shows that the real value of a
cellular communication system is to provide high

Fig. 7 – Increasing DDF with increading subscriber types data speeds during mobility or in other words, to
provide mobile data to mobile users.

96 © International Telecommunication Union, 2021