Page 6 - 5G Basics - Core Network Aspects
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These experiments showed that the requirements to the 5G for a maximum data rate of up to 20 Gbit/s and
a response time from 1 ms can be successfully implemented in the millimetre wave bandwidth.
Programmability bravely enters our lives. This is where some operation of the network maybe entrusted to
the software that, for example, will collect the statistical data on user’s move, meteorological condition
around him, real obstacles on the way of the signal and build a dedicated traffic route known in the experts’
world as network slice instance. Such instance is a set of managed run-time network functions performed at
physical/logical/virtual resources. In other words, the network slice instance forms a complete instantiated
logical network to meet certain network characteristics required by the service instance.
As long as we drop to the level of implementation for the actual delivery of the information in the 5G
networks, i.e., transport layer, some router functions are now entrusted to the software defined switches to
be set up at the mobile base stations. This is known as frontfaul solution (Fronthaul (FH): Link connection
between the base station baseband and remote radio head) compared to the well-known backhaul (BH) that
is a link connection between the base station and higher level network elements.
Network slicing, running multiple logical networks as virtually independent business operations on a common
infrastructure, will also apply to the transport networks. The transport network already provides isolation
between its clients that share a common infrastructure (e.g. a fibre) by using either TDM (e.g. OTN) or packet
(e.g. VLAN) multiplexing.
When a terminal for URLCC and eMBB is moving from a cell to an adjacent cell, the dedicated resource should
be re-allocated to the link connecting to the adjacent cell according to the position of the terminal in a slice.
If this re-allocation is conducted by the orchestrator and the reallocation covers all of the terminals, large
traffic for this control will be flown. In such a case, the controller can reallocate the resources (instead of
orchestrator) by its own decision. The controllability for the reallocation is expected to be transferred from
orchestrator to the controller in FH/BH.
Increasing number of devices and their high concentration at the given square put additional requirements
on operation of those in a small and femto cells. As mobile broadband moves to IMT-Advanced and beyond
with the increased implementation of small cells, there is a need to have access to wireless short-haul very
high capacity links in urban areas close to users where in many cases fiber is not available.
In a small cell radio-over-fiber (RoF - fibre-optic transmission of waveform for radiocommunication services)
technology, may be used for delivering the information from antennas to base station and further to
information recipient. This way the radio signal is converted into the optical signal that may be delivered via
optical fiber with almost no loss of signal strength. RoF is of particular help in the area with difficult air
propagation of signals (mountains, constructions radio shadow zones). The waveform of the radio signal
represents the essential physical information for radiocommunication services. During fibre-optic
transmission the waveform stays unchanged.
ICN is also considered as a potential networking scheme to be deployed and operated by software-defined
networking (SDN) on network slices created and programmed by network function virtualization (NFV),
network softwarization and in-network processing. Another beauty of the Information-Centric Networking
(ICN) is in exploring a new identification mechanism that may create alterative to the IP addressing in
networks.
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