Page 102 - ITU Journal Future and evolving technologies Volume 2 (2021), Issue 4 – AI and machine learning solutions in 5G and future networks

ITU Journal on Future and Evolving Technologies, Volume 2 (2021), Issue 4

Identify links with heavy or low load based on their utilization is within the target range). Specifically,
link utilization, check the link library to search for the links are optimized through the transfer of some
their neighbor links that carry low load or whose nodes with heavy load on these links to other links.
link utilization is within the target range, confirm It reduces the variance in the utilization of all links.
whether any link combination can be conducted in During network topology optimization, the
accordance with the rules for link optimization, and iteration of network topology is carried out every
combine the links that comply with the rules.
hour, which is 24 times a day.
In the case where links cannot be optimized in the Regarding the topology optimization system, the
above way, partial link optimization can be network topology iteration carries out every hour
implemented. 1) Identify the links adjacent to the after the first topology recovery. Therefore, each
sub-links or hanging links of the links with heavy day, 25 scores on link ‘status calculated’ based on
load; 2) Opt for one appropriate neighbor link and the evaluation formula can be achieved. During the
connect those sub-links or hanging links with the topology iteration, the previous day's network
neighbor link in accordance with the related rules.
topology with the highest score is used to start the
next round of network topology optimization.
Finally, the result of the optimization showed that
The optimization by node transfer is applicable to
all the links (including those whose link bandwidth the proportion of links with balanced load increased
by 86%, as shown in Fig. 7 below.

Fig. 7 – Network topology optimization process

3.5 Unique network topology restructuring The network topology restructuring aims to
for better topological structure optimize network topology in a more complete way.
In other words, it changes the status of the links that
Network topology restructuring is to optimize the carry unbalanced load for a long time. In the study,
links that carry heavy or low load for a long time we extended the distance between two neighbor
when basic network topology optimization is nodes to 1000 meters and witnessed a 169%
completed [28,29]. increase in the proportion of the links with a
First, identify links with a heavy or low load for a balanced load through the network topology
long time. Second, split the link with heavy load into restructuring [31,32], as shown in Fig. 8 below.
two links through either of the following two ways.
One is to connect the link with two neighbor nodes
(node G or H) respectively by adding two new edges.
The other is to connect it with another main link
that carries low load. By doing so, the iteration of
the new topology carried out afterwards based on
the new structure improves the utilization of all
links [30].

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