Page 101 - 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

First, find the main links whose end nodes are G or on the network service rules, rules for assessing
H via the DFS algorithm [20,21], and save all such node levels [22,23], and the requirements for link
main links in the link library. For cross-connected load balancing.
main links, select the one that is comparatively max object_ratioavg – (Eavg+Emin+Emax) – α · sub_ratio
longer than the others in accordance with -β · hang_ratio (1)
constraint rules on cross-connected links.
Explain:
Regarding the sub-links and hanging links, the
innovative "Node-Removing Method" is applied to object_ratioavg: Daily average of the ratio of links
sort them out when all main links have been whose bandwidth utilization is optimized to the
identified. Specifically speaking, after main links in target range per hour
the network topology are removed, the related sub- Eavg: Daily average of the E-value per hour that
links and hanging links will be disconnected indicates network load balancing
accordingly. In this way, all the links in this network
topology can be sorted out by category, and all the Emin: Minimum E-value per hour of each day
links of the topology will be recorded in the library Emax: Maximum E-value per hour of each day
by category.
sub_ratio: Proportion of nodes on sub-links to those
1) Select one main link from the link library, and on the entire link (daily average of values per hour)
then remove it by using NetworkX. hang_ratio: Proportion of nodes on hanging links to
2) Execute the connected_components() method those on the entire links (daily average of values per
to identify all connected sub-graphs [15]. hour)
3) Review all these sub-graphs and remove the α,β: Constant coefficients that are set to 0.02 and
sub-graphs that are not related to the current 0.05 respectively.
main link in accordance with the existing node Edge addition: Distance between two nodes that are
connections.
to be connected by adding an edge for topology
4) Associate the sub-links and hanging links in the optimization should be within 500 meters.
sub-graphs that have been removed in step 3 Number of nodes on each link: Maximally 30 nodes
with the correct main link, and update the on each link.
collection of neighbors’ links in the link library.
5) Continue to remove other main links in the Target range of link bandwidth utilization:
3
7
same way until all the sub-links and hanging [ , ]
5
5
links in the graph are associated with
appropriate main links, as shown in Fig. 6 Formula used to calculate E-value:
below. ∑

= (2)

A
"E" is the variance of the link bandwidth utilization
(fp) of all links in the network topology.
"μ" is the average of bandwidth utilization of all the
links in the network topology. In the formula, fx is
the traffic on the nodes (excluding the start and end
nodes) on the link, and A stands for the maximum
node capacity that one node (excluding the start
and end nodes) on the link can possess.
3.4 Build and complete network topology
optimization and find the optimal

Fig. 6 – Node removing method solution through iteration
Network topology optimization for load balancing can
3.3 Evaluation of network topology
be implemented in three different ways [24,25,26,27],
The following formula describes how the effect of including link combination, partial link optimization,
network topology optimization is evaluated based and the optimization by node transfer.

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