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impedance matching and coupling circuit design, the application of Orthogonal
Frequency Division Multiplexing (OFDM) in PLC and frequency hopping modu-
lation and demodulation techniques etc. These technologies improve the point to
point communications of PLC essentially. The reliability of point to point com-
munication does not mean the high reliability of PLC networks, so it is necessary
to establish routing for the PLC. Q. Gao, J. Y. Yu etc [11] proposed clustered
simple polling (CSP) and neighbor relay polling (NRP) algorithm, these schemes
solve the ”silent nodes” problem in an Automatic Meter Reading System Using
Power-Line Communications and can be evaluated in terms of reliability and ef-
ficiency via selecting suitable relay node. But these two schemes did not consider
the situation that some nodes in the network send information at the same time
which can cause serious data conflict in the channel, the channel utilization will
be very low and may not meet the QoS (quality of service) of communication
system.
This paper presents an artificial cobweb routing algorithm (ACRA) for tree-
type physical topology of low voltage distribution based on artificial cobweb
structure proposed in [12]. The artificial cobweb routing algorithm is further
completed. This paper detailed describes the process of artificial cobweb algo-
rithm, presents corresponding routing maintenance and restructuring strategy.
Experimental platform is based on Opnet 14.5. The simulation results show that
the artificial cobweb routing algorithm has a greater advantage and practicality
in guaranteeing the QoS and reliability of power line communication.
2 Artificial Cobweb Routing Algorithm
2.1 Topology of LVPLC
Signal attenuation between phases is very large for the three phase power distri-
bution grid of the secondary side in the transformer. Without phase coupling,
each phase can be regarded as parallel and relatively independent. So that topol-
ogy of any one phase can be the focus of research. According to the physical
topology of low-voltage distribution proposed in reference [13], this paper estab-
lishes a single-phase power distribution network shown in Fig.1. BS (Base Sta-
tion) is responsible for collection and coordination of the data of each terminal
node in the network, and connected with wide area network (WAN) for informa-
tion exchange with external. In practice, signal attenuates with the transmission
distance [14], therefore only the terminal nodes, the physical distance of which
are close to the BS, are able to ensure the reliable communication. In this case,
traditional polling methods cannot guarantee the direct communication between
BS and the nodes far away from BS, the success rate of communication may be
very low [11]. In order to solve this problem, a novel method called artificial cob-
web routing algorithm is proposed. In this method, firstly a communication route
is established between BS and part of the nodes. Then the nodes are regarded
as relays to expand the communication distance, and gradually all nodes are
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