Page 100 - 5G Basics - Core Network Aspects

1 Core network aspects

Each LINP is isolated from others, so it has to be managed independently from others. At the same time, the
management system for an LINP has to collaborate with the VRM. So, it is necessary to carefully define which
part of management can be done by the LINP Manager, and how to align it with that of physical resources.
By considering the rapid changes of virtualized network environments, the visibility is essential for network
management operations such as monitoring, fault detection, topology awareness, reconfiguration, resource
discovery/allocation/scheduling, and customized control. One of the approaches for supporting
management is to develop an integrated management system that may be implemented within the
virtualization layer.
Therefore, network virtualization should provide an integrated management system that can access both the
information of physical resources and virtual resources.

8.7 Mobility

Mobility in network virtualization is a movement of virtual resources, including users and services which are
composed of e.g., computing resources, system images, and applications across LINPs. Each virtual resource
can be moved according to users' demands and in order to retain the performance of LINPs. For example,
users can be dynamically attached or reattached to one of the LINPs depending on the application
characteristics. At the same time, to maintain the services' continuity for users, the services can also be
moved together with the users without service downtime. In addition, the virtual resources can be added to
improve network performance or removed for load balancing or energy-saving purposes.
To do that, it is essential that the virtual resource requirements from each LINP and users should be identified
in advance or in a real time manner, and then these virtual resources should be moved to the corresponding
LINPs in a limited amount of time. Since each LINP has different requirements, such as high network
performance, low network latency, and energy efficiency, these requirements should be maintained in LINPs
during an entire cycle of creation and termination of LINPs by supporting mobility in network virtualization.
By doing so, flexible resource allocation to any LINP, real-time LINP maintenance and disaster-resistant
network can be achieved.

Therefore, network virtualization should support mobility which is the ability of a movement of virtual
resources in order to fulfil the requirements of LINPs.

8.8 Wireless

Wireless virtualization needs to consider some unique characteristics such as limited resource usage or signal
interference that do not happen in wired networks. One of the biggest challenges in wireless virtualization is
how to virtualize wireless links. Establishment of a wireless link requires the configuration of wireless channel
parameters such as a channel of operation, appropriate setting of transmit power, or receiver sensitivity
between a transmitter and a receiver. In order to provide two separate LINPs to users, communication
activities from one LINP should not affect any reception behaviour on the other LINP if these two LINPs are
to coexist on the same hardware.
However, the characteristics of wireless links can infer requirements such as coherence and isolation.
Coherence means that when a transmitter of one LINP is active, all of the corresponding receivers and
potential sources of interference as defined by the LINP should be simultaneously active on their appropriate
channels of operation. Isolation means that when a node belonging to one LINP is receiving some signal
pertinent to the LINP, no transmitter of a different LINP within the communication range of the receiver
should be active in the same or a partially-overlapping channel [b-Mishra].
Therefore, network virtualization should provide scheduling methods for transmission activities across
different LINPs [b-Smith].

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