Fog layer consists of various equipment and nodes. Datacenters are one of the
main components. Even a classic and enormous Datacenter can be placed in the
Fog layer if it is closer to the abstraction layer than the Cloud environment.
For easier detection, first, we clarify Datacenter types that lie on Fog layer.
The definition of classic datacenters is clear, sets of servers and hosts that
provide services through virtualization and resource allocation techniques.
Mini Datacenters are just a set of servers which, in terms of size and power,
can be equal to a small part of the commonly used Datacenters. The main pitfall
that caused the writing of this section is the inappropriate use of the terms
Micro and Nano Datacenters. Micro Datacenters as previously mentioned, are
often a resource-rich stand-alone server or host that is capable of offering
various services. On the other hand, Nano Datacenters are usually a capable SBC
or tiny device that can provide proper communication, processing, and storage
services. The last two terms are mistakenly replaced with each other and the
above explanation tries to categorize them according to their features.
the following, first, we aimed to introduce Fog Nano Datacenters attributes and
explain them. Obviously, the high variety of Fog Nano Datacenters makes it
difficult to explain all the features, therefore; we can only cover the basic
and essential features. Next, we make a comparison between Micro and Nano
Datacenters. Last, we will check features on different Fog Nano Datacenters.
Energy and operational
cost efficiency: These devices are tiny and need to consume little energy.
Many of these Fog Nano Datacenters operate through batteries rather than
directly connect to the wall outlets. Considering the importance and necessity
of their continuous operation in many applications, energy efficiency and
low-cost performance are two vital factors. For example, Fog Nano Datacenters
like Raspberry Pi, BeagleBoard and Intel Edison can operate with 5 volts and 2
amps which can be obtained from the power banks or batteries quite easily.
These devices are remarkably cheap and have adequate resources for many
Mobility: One of the
most important shortcomings in Cloud Computing was the mobility issue that Fog
Computing attempted to answer it. By using Fog Computing in applications that
mobility is crucial like Vehicular ad hoc networks (VANETs) or Smart
Transportation, communications between cars and infrastructures become more
accurate and responsive. Fog Nano Datacenters makes mobility even more
reachable. These are small and lightweight devices that make it easier to move
around. Some devices, such as Smartwatches and phones are naturally fitted by
people but, other equipment can be moved through robotics and drones.
Interoperability for Fog Nano Datacenters can help to make this feature
feasible. By adding interoperability, the variety of equipment is no longer a
problem and we can scale heterogeneous environments in different forms without
much difficulty. Actually, these devices
can provide services for various applications, from a smart room to a large
shopping mall or industrial factory. Scalability can have a direct impact on
coverage, network dimensions and equipment densities.
layer has a distributed architecture that sits between perception and core
layer. In contrary, Cloud Computing has a centralized architecture and all
requests are sent to a specific point. This may cause a bottleneck which leads
to congestion, low availability and accessibility. Fog Nano Datacenters are
actually tiny Fog nodes that build up a huge portion of this technology. They
are distributed in Fog layer and consist of heterogeneous devices. Applicants’
requests can be segmented and answered through multiple devices.
Resource allocation: To
achieve the ideal level of efficiency, Fog Nano Datacenters should be able to
provide required services. In general, this includes processing, storage and
communication services. Network interoperability is one of the most important
communication services. Of course there, are other optional services like:
Monitoring, Analysis, Resource Management, Data Virtualization/Standardization
and VM Scheduling. Deploying and providing these features are mainly related to
system’s goals and availability of resources. At the end, it should not be
forgotten that the purpose of these Fog Micro Datacenters is not to process
heavy operations, but rather to provide services for temporary and transient
Dimensions and weight of devices are important. These devices should be
lightweight so can easily be moved. In the mobility scenarios (Human, aerial
and robotics) this feature is a decisive factor. Also, small dimensions allow
them to be easily applied and run.
Heterogeneity: The varieties of nodes that
can operate as Fog Nano Datacenter are very high and still increasing. This
includes hardware, software and architectural features. This heterogeneity is
really helpful for end users because it provides a higher level of flexibility
for things communications. In heterogeneous environments interoperability is
really crucial and hides differences.
the following, first Table.2 demonstrates a comparison between Micro and Nano
Datacenters then, in Table.3 it shows some detail information about previously mentioned
Fog Nano Datacenters.