Page 271 - From Smart Grid to Internet of Energy

242 From smart grid to internet of energy

transmitted by the service providers. Furthermore, this two-way communication
among service providers and customers can be utilized to enhance demand man-
agement, maintenance, and planning capability of service providers.
ItisalsopossibleinanySGsystemsthattherewillbeexistalargenumberofthe
SMs as well as many APs. Therefore, mesh network structures are widely taken
into account in the AMI communication infrastructures. Since the unlicensed
ISM bands are utilized by numerous communication systems in urban areas, com-
munication infrastructure of the AMI systems highly suffers from the interfer-
ences. Therefore, performances of the AMI systems operating in the unlicensed
frequency bands decrease and this situation causes to high latency and data losses
as well as the security problems. The utilization of licensed spectrum for enabling
communication among the APs and service providers generally requires high
costs. The CR technology can be efficiently used in backhaul networks of the
AMI systems since its advanced spectrum access characteristics will ensure to
improvesystemperformance[49].Inaddition,self-configurationandeasydeploy-
ment properties of the CR technologies make them potential candidates for
employing in communication infrastructures of the AMI systems [51, 95].

6.6.7 Wide-area situational awareness

The last considered SG application is wide-area situational awareness (WASA)
that realizes remote monitoring, control and protection of the SG systems by
employing the PMUs and IEDs. In addition, it has self-repairing feature through
local control and quick response characteristic compared to the conventional
control managed by a control center. Furthermore, the WASA can completely
maintain the power systems against the power outages and unforeseen situa-
tions. The communication networks of the SG systems should face up to several
important problems such as interference, latency, and insufficient capacity that
will lead to significant issues on security, reliability and efficiency of the SG
systems. Moreover, deployed and large-scale characteristics of wide areas also
cause various challenges for the WSNs such as maintenance, the necessity of
using different spectrum, fading, interference, shadowing, and multi-path prop-
agation. These challenges require utilizing the improved communication tech-
nologies to transmit predicted state of the all system. Therefore, the CR
technology can also enhance the system performance of WASA and it not only
improves the spectrum efficiency, but also enhances the system capacity
through advanced spectrum management methods.

References
[1] B. Wang, K.J.R. Liu, Advances in cognitive radio networks: a survey. IEEE J. Sel. Top. Sign.
Proces. 5 (2011) 5–23, https://doi.org/10.1109/JSTSP.2010.2093210.
[2] S. Haykin, Cognitive radio: brain-empowered wireless communications. IEEE J. Sel. Areas
Commun. 23 (2005) 201–220, https://doi.org/10.1109/JSAC.2004.839380.