Page 90 - From Smart Grid to Internet of Energy

76 From smart grid to internet of energy

concept defines mutual connection procedure between all sides of customer and
network operators. Therefore, the installed communication medium should
ensure bidirectional data transmission between customers and network opera-
tors in addition to customer-network operator channel. The communication
module of smart meters is equipped with several types of communication tech-
nologies and operates independent from AFE and recording sections of smart
meter. Thus, an error occurred on connection module does not cause any dis-
ruption on smart meter functions. The communication interface of smart meter
includes wireline or wireless transmission technologies as discussed earlier.
Moreover, the communication technologies should cooperate with network
architectures such as HAN, NAN, and WAN as depicted in Fig. 2.4 where area
networks are based on many protocols and services on layer structure for ensur-
ing secure and reliable communication. The layer structure of any network is
comprised regarding to some standards that most widely accepted on is open
systems interconnection (OSI) model comprised by seven layers. The initial
layer of network architecture is physical layer (PHY) that is responsible for
electrical, physical and optical transmission of data as its name implies. The
second layer known as data link layer where medium access control (MAC) pro-
vides direct connection between two nodes and corrects erroneous data trans-
mitted by PHY layer. The MAC layer enables Ethernet, IEEE 802.11 Wi-Fi,
IEEE 802.15.4 and ZigBee type communications to operate at the data link
layer. The third layer of OSI conceptual model is network layer that is respon-
sible for ensuring connection between different network types of nodes. Many
types of communication devices and technologies causing a heterogeneous
architecture comprise the smart grid. Therefore, network layer enables each
node with an address and communication technology to operate on the same
area network [2, 10].
The utility grid requires a smart metering network including high and low
bandwidth sections if we recall Fig. 2.4. The WAN meets high bandwidth
requirements with its huge number of communication channels and connections
with data concentrators and gateways. The communication networks that are
used in smart metering are classified into three groups as shown in Fig. 2.7
and communication technologies are listed under each area networks with their
network layer interaction.

2.3.2.1 Home area network
HAN is the fundamental network architecture deployed at customer premises to
monitor and control integrated devices and to perform smart metering pro-
cesses. It integrates many devices such as HEMS associated smart appliances,
smart meters, smart sockets and plugs, and PEVs. HAN facilitates interaction of
energy management systems and smart appliances to improve control and com-
fort of users and network operators. One of the most important benefits of HAN