170 Software Networks
We can also cite other advantages, such as the low attenuation of
the signal over the fiber, so the datacenter can be far away from the
source. The cost of connection is also going down, thanks to
multiplexing on the same antenna, but also on the same optical fiber.
The complexity of the access network is eliminated, and the
datacenter handles this complexity with appropriate virtual machines.
This technology is found in the cabling solutions used at certain large
stadia or shopping centers.
The main disadvantage stems from the use of FTTA (Fiber to the
Antenna) which is necessary for the communication. If the building
containing the Wi-Fi access points is not cabled, then installing an
optical cable can often be extremely costly. The optical fiber is
connected to the datacenter by a BBU (BaseBand Unit) and, on the
other end, is connected to the physical antenna by an RRH (Remote
Radio Head).
The standardization currently under way for NFV (Network
Function Virtualization) includes C-RAN. Functions in the NFV
environment are defined to decouple the work carried out on the node,
which was previously done by the antenna, and move it to a
datacenter.
Whilst the C-RAN architecture is an interesting option for
countries wishing to develop a new infrastructure, it is much less
attractive to countries which already have a local-loop infrastructure
for RAN. In such cases, the proposition is to keep the existing
structure and add Cloudlets near to the antennas to perform
computation locally. The computation pertains to the signal but also to
the signaling, with algorithms to manage handover or the choice of
connection to be favored when multiple options are available. This
architecture is illustrated in Figure 6.18.
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We can also cite other advantages, such as the low attenuation of
the signal over the fiber, so the datacenter can be far away from the
source. The cost of connection is also going down, thanks to
multiplexing on the same antenna, but also on the same optical fiber.
The complexity of the access network is eliminated, and the
datacenter handles this complexity with appropriate virtual machines.
This technology is found in the cabling solutions used at certain large
stadia or shopping centers.
The main disadvantage stems from the use of FTTA (Fiber to the
Antenna) which is necessary for the communication. If the building
containing the Wi-Fi access points is not cabled, then installing an
optical cable can often be extremely costly. The optical fiber is
connected to the datacenter by a BBU (BaseBand Unit) and, on the
other end, is connected to the physical antenna by an RRH (Remote
Radio Head).
The standardization currently under way for NFV (Network
Function Virtualization) includes C-RAN. Functions in the NFV
environment are defined to decouple the work carried out on the node,
which was previously done by the antenna, and move it to a
datacenter.
Whilst the C-RAN architecture is an interesting option for
countries wishing to develop a new infrastructure, it is much less
attractive to countries which already have a local-loop infrastructure
for RAN. In such cases, the proposition is to keep the existing
structure and add Cloudlets near to the antennas to perform
computation locally. The computation pertains to the signal but also to
the signaling, with algorithms to manage handover or the choice of
connection to be favored when multiple options are available. This
architecture is illustrated in Figure 6.18.
www.it-ebooks.info