Fig. 5 Network topology of INSTEON [13]
5. HomePlug Command and Control (HPCC) standard is
developed by the HomePlug Powerline Alliance for
home/building automation, remote monitoring and
control, the white paper version 1.0 was released in
2008 [14, 15], which
contains a PHY and MAC layer in
this version, but will be expanded to network and host
layers.
Fig. 6 shows the PHY (Physical) block diagram of
HPCC standard, which is the first layer in the seven-
layer OSI model. It defines the electrical, mechanical,
procedural, and functional specifications for activating,
maintaining and deactivating the physical link
between communicating network systems.
Fig. 6 PHY block diagram of HPCC [15]
The HPCC uses a patented Differential Code Shift
Keying spread spectrum (DCSK) modulation on the
narrow-band power line. The data transfer rates is
7.5Kbps on the PHY Level. It
will work also with
high-speed broad-band networking, such as HomePlug
1.0, and HomePlug AV.
III. IMPLEMENTATION
From the above descriptions the HomePlug C&C
might be the most recent and more advanced for home
automation system. To implement this technology for
home automation a PLC modem (IT700) from Yitran was
selected [16], the main reasons are:
1. IT700 is a fully integrated PLC microcontroller for
command and control applications on a single chip,
which incorporates an extremely reliable PHY, line
driver, 8051 mcu core with 256 KB flash ROM for
protocol stack and firmwares, 16KB RAM, and 24
GPIOs (fig. 7).
Fig. 7 IT700 block diagram [16]
2. IT700 follows the HomePlug Command and Control
standard and uses PLC ready transceiver technology,
which is high immunity to signal fading, phase/
frequency distortion, various noise characteristics, and
impedance modulation.
3. Yitran offers complete reference design and Plug In
Module (PIM) with integrated Analogue Frond End
(AFE), line coupler and power supply interfaces for
quick application prototyping and development (fig. 8).
Fig. 8 IT700’s Plug In Module [16]
4.
The IT700 incorporates reliable Physical Layer (PHY),
high-performance Data Link Layer (DLL) and Network
(Y-Net) protocol [17]. The Network Layer (NL) is
implemented using an advanced and compact adaptive
routing and automatic addressing mechanism, enabling
optimal and simple powerline communication (tab. 1).
Tab. 1 Y-Net protocol stack firmware and OSI Layers
Since the IT700 PIM supports up to network layer
only, all other above layers must be executed by other
processor, therefore in the PLC control network two types
Application
Presentation
Session
Transport
Network (NL)
Upper Layers
Y-Net protocol
stack firmware
MAC
Physical (PHY)
Lower Layers
External Circuitry
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