Page 196 - Kaleidoscope Academic Conference Proceedings 2021

2021 ITU Kaleidoscope Academic Conference

this network requires fundamental changes to the current
mobile network architecture to add flexibility and scalability.
For these purposes, the fifth-generation network uses
technologies such as Software Defined Networks (SDNs)
and Network Function Virtualization (NFV) to provide a
wide range of diverse services on a common physical
infrastructure. In different applications of fifth generation
networks, there are different requirements that cannot be
implemented by a rigid architecture. Network slicing
customizes each slice for each service by devoting the right
resources to each slice. The service associated with each
Figure 1 – Sliced 5G network with different virtual slices network slice determines the resources required for that slice.
on one physical infrastructure Network slicing is done based on the necessary
characteristics that we need in each slice [7]. These features
Each slice can be used for different services and use cases. are as follows:
Network slicing creates a virtualized network with logical
components which can provide use case requirements. This • Isolation: Isolation is an essential feature in any slice to
logical network is flexible and adjustable in case of new ensure the safety of users of that slice. One way of
requirements. With introducing the concept of slicing, new isolation is to separate the physical resources and not to
functionalities come along, slice creation and management share them. However, this method leads to inefficient use
for instance. For this purpose, we have different functions of network resources. Another solution is to virtualize
created to manage the whole process from slice creation to resources with a shared physical resource. The third way
end use [5]. SDN and NFV together would allow us to take is to determine the policies to access a shared resource [8].
control of these slices and to alter them when required • Customization: This feature ensures that the resources
without having to deal with physical infrastructure in the dedicated to each slice delivers the services to the tenants
network. Moreover, 5G network slicing allows slices to be of that slice.
isolated, increasing the network’s revenue. This way, • Programmability: This feature helps individuals to control
operators get to offer different type of services with different the resources available in their slices.
demands [4].
• Automation: With this feature, slicing is done
automatically without manual intervention. This is done
2.1 5G network service categories with the help of information that the user sends about the
capacity, latency and slicing schedule information.
A 5G network is expected to support the vast majority of use • Flexibility: The flexibility of the slices depends on the
cases and services. Due to the varying requirements, 5G resources allocated to each slice which can be done by
networks need to be sliced. Slicing should be properly changing the use of slice resources or changing resource
exploited in 5G networks to provide use cases to the policies. Another issue here is the ability to change the
acceptable slices. Network slicing must be flexible and amount and type of resources allocated to each slice when
dynamic to adjust to the changing requirements of use cases. necessary. In this case, we need the agreement of both
According to a study by the International parties; Because by changing this feature, the performance
Telecommunication Union (ITU), the main applications for of other slices using these resources is also affected [9].
5G networks fall into three categories where there are
different and diverse needs. Different use cases require 2.3 5G network slicing architecture
different features, such as ultra-high bandwidth, very low-
latency, ultra-reliability and massive IoT. These categories Here we discuss the two most studied architecture in 5G
are as follows: networks: NGMN and 5G-PPP. NGMN architecture
• Massive Machine Type Communication (mMTC): consists of 3 layers: service instance layer, network slice
Massive IoT or mMTC [6] uses the sliced 5G network to instance layer, resource layer. The service layer indicates
connect different embedded sensors all over the world. the types of services, whether it is an end-user service or a
Smart cities can be a good example of this category. business service. In this architecture, service instance
• Enhanced Mobile Broadband (eMBB): Enhanced mobile provides services and all services can be either presented by
broadband use cases are mainly related to VR videos. network operators or by a third party. A network instance is
• Ultra-Reliable and Low Latency Communication made by the operator of the network, using a network slice
(URLLC): URLLC use cases are mainly about remote blueprint. The requirements of each service instance are
control of critical devices [5]. considered by the network slice instance. The slice network
instance might be originated from one subnet or another
2.2 Network slicing concept and principles instance [1]. The 5G-PPP architecture provides a more
detailed architecture of the fifth-generation network.
The main purpose of providing 5G systems is to support a However, it has the same basics as NGMN. This
wide range of different services and meet users’ architecture defines 5G network slices as a 5-layer network:
requirements. To achieve this goal, a network is needed that infrastructure, network functions, management layer,
has different features depending on the service. Reaching business performance

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