Page 165 - From Smart Grid to Internet of Energy

142 From smart grid to internet of energy

FIG. 4.6 Generic network architecture model of ITU-T Rec. G.9902 (Gh.nem). (From Narrow-
band orthogonal frequency division multiplexing power line communication transceivers for ITU-T
G.hnem networks, ITU-T Rec. G.9902, October 2012. [Online] Available: http://www.itu.int/rec/T-
REC-G.9902 (Fig. 5-1), with permission.)

domain. Each registered node in a domain is identified by its domain ID and
node ID. Each domain has a domain master (DM) that is responsible for man-
aging the operations of all other nodes. The DM also performs admission, res-
ignation and other domain-wide operations. In the event of the node serving as
DM fails, the DM mission is delivered to another node of the domain. Inter-
domain bridges (IDB) provide the connection between different domains in
the same network. It is worth noting that G.hnem domains can also connect
to non-G.hnem domains that are called “alien” domains. A G.hnem network
containing several interconnected domains are depicted in Fig. 4.6.

4.4.1.1 PHY layer
Even though the G.9902 can support different bandplans, it should necessarily
support at least one bandplan. The CENELEC bands in the range of 3–
148.5 kHz are considered as three bandplans: CENELEC-A (35.9375–
90.625 kHz), CENELEC-B (98.4375–120.3125 kHz) and CENELEC-C/D
(125–143.75 kHz). Similarly, the FCC band in the range of 9–490 kHz is taken
into account as three bandplans that are FCC (34.375–478.125 kHz), FCC-1
(34.375–137.5 kHz) and FCC-2 (150–478.125 kHz). On the other hand, the
ARIB bandplan employs 154.7–403.1 kHz frequency range.
The PHY transmitter of ITU-T G.9902 is based on the G3-PLC. This trans-
mitter structure employs Reed-Solomon (RS) and convolutional coding based
FEC systems. While the inner convolutional coding utilizes ½ rate and 7 con-
straint length, the outer RS encoder uses input blocks up to 239 bytes. An inter-
leaving scheme with two-dimensional characteristic is exploited to prevent the