Page 388 - 5G Basics - Core Network Aspects

1 Core network aspects

11.1 Charging mechanisms

11.1.1 Online charging
For MC-Streaming, online charging is a charging mechanism where charging is done in real time taking into
consideration multiple accesses. Therefore a direct interaction is required between resource/session/service
control entities and the charging system. For the MC-Streaming service, several entities can be used to fulfil
online charging in different scenarios.
In the architecture of MC-Streaming, MSCC-FE provides a content management and control function, as well
as optional content distribution function. It is responsible for content preparation and content protection.
All streaming content would pass through it before distributing to subscribers. Therefore, the services to be
charged by usage time, e.g., linear TV and video conference can optionally be fulfilled by MSCC-FE.
MSCD-FE is responsible for caching and storing content and associated information, as well as delivering
received content from MSCC-FE to subscribers. Therefore, content and streaming related charging can
optionally be fulfilled by MSCD-FE.
MSAC-FE is responsible for user interaction control such as programme selection, forwarding and rewinding.
It allows multi-connection devices to choose or purchase streaming content on demand. Interaction between
users is also a responsibility of MSAC-FE. Therefore, content related charging can optionally be fulfilled by
MSAC-FE.

In the multi-connection environment, each network has its own charging strategies and policies. Charging
information can be generated by many functional entities. Hence, it is required to avoid redundant charging
when accumulating different usage records collected from different networks or from different systems in
one network.
11.1.2 Offline charging

Offline charging is a charging mechanism where charging is done periodically (e.g., daily or monthly), instead
of in real time. All usage information is provided to a billing system such as a charging data record (CDR),
which contains detailed usage information. And charging will be completed by the billing system according
to the charging strategy. The billing system does not need to interact with a service directly during the process
of the service, which would reduce service performance. For MC-Streaming, offline charging has an intrinsic
risk since a subscriber might generate high expenses in short periods of time.

For the MC-Streaming service, charging information can be generated not only by MC-Streaming, but also by
the underlying networks. Different functional entities in MC-Streaming can be used to generate charging
records, according to a service's charging policy. For example, MSCC-FE or MSCD-FE can be optionally used
to charge for flow or transmission related policy, and the service itself can be optionally used to charge for
content related policy.

11.2 Charging policies
11.2.1 Duration based charging

In duration charging, a user is to pay for usage duration of a service. The quality of content has little effect
on cost. The capacity of the underlying network has a greater influence on the quality of service. This means
even if the network is overloaded, users still have the same cost but for a lower service experience. Therefore,
it is reasonable to deploy this strategy in the networks which have a stable QoS.
For MC-Streaming, both the service itself and underlying networks can optionally generate charging records.
However, it is more reasonable for MC-Streaming to fulfil duration charging, since it has overall information
about the service usage. If not, it may be complex and possibly make a mistake when charging across multiple
access networks.

11.2.2 Flow based charging
Flow charging is based on the flow of traffic that a user sends or receives, independent of the service being
used. Because different links have different rates and may generate different charging records, it is

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