Page 92 - 5G Basics - Core Network Aspects

1 Core network aspects

Introduction

Future networks (FNs) are networks that will be able to provide revolutionary services, capabilities, and
facilities that are difficult to support using existing network technologies. One of the basic objectives of FNs
is service awareness. The number and range of services are expected to explode in the future, and FNs need
to adapt to the surge in the number of services [ITU-T Y.3001]. That surge in the number of services makes it
difficult to satisfy the requirements of every service on a single network architecture. However, it is
unrealistic to realize heterogeneous network architectures using multiple physical networks because of the
installation, operation, and maintenance costs. FNs therefore need to realize diverse services and
heterogeneous network architectures on a common physical network.
The future information and communication infrastructure is expected to support arbitrary kinds of social and
economic activities. For example, while a proliferating number of network services are emerging and such
services require high-speed, large-volume, low-latency network connectivity for voice, video, database
communications, it is also imperative to ensure low-power consumption. A mixture of contradicting goals,
including those described above, is to be resolved by the flexibly reconfigurable networks that accommodate
multiple virtual networks with different capabilities. It is therefore crucial to make the networks more flexible
and more reconfigurable so that they continuously and dynamically evolve to adapt to the changing
requirements for future network services and applications. It is especially important to optimize the usage of
the limited resources and maximize the number of users of the resources by quickly and dynamically adapting
to environmental changes, for example, the emergency situations caused by natural disasters, through
tailoring the amount and the quality of resources allocated for each virtual network and switching between
multiple virtual networks with different capabilities.

At the same time, to make diverse services flourish, it is preferable for networks to provide easy methods for
experimenting and/or small-scale deployment. This has to be done without causing unexpected effects for
others, so it is often done by building completely separate networks. If experimental networks and/or test-
beds could be built on real networks that share common physical networks and could still provide isolated
network environment, it will give developers, providers, and users of the emerging technologies an ideal
environment to design, develop, and evaluate new services.

Network virtualization is a technology that realizes isolated and flexible networks in order to support a broad
range of network architectures, services, and users that do not interfere with others. It also enables the easy
establishment of experimental networks and accelerates research and development on future network
technologies. Therefore, network virtualization is considered as a key technology for realizing FNs.
This Recommendation provides the framework of network virtualization technology.

82