In the battle to get the most reliable and cost efficient device, equipment providers have to look at several aspects like the continuous development of technologies, the new powerful microcontrollers (mono-chip solutions), the volume of transmitted data, the frequency of their collection and the diversity of the topologies on the field. All these points force the metering actors to find the optimal way of communication. Hybrid solutions PLC & RF are an option.
Hybrid solutions are available on the market since a long time back. There are many projects worldwide presenting this type of alternative. The main reason is the heavy requirements of reliability demanded by the utilities and in general also by the market.
Andrea Informatique has been working for many years in PLC technologies, and has implemented, validated and certified THUNDER in Cenelec A and FCC bands. THUNDER is a full soft G3 PLC solution for mono-chip cost effective solutions. Thunder G3 PLC solution includes PHY, MAC & ADP layers.
Andrea Informatique has also been working in wireless solutions and has implemented the Wi-SUN soft solution HURRICANE. HURRICANE is a performant and modular solution based on the FAN specifications of the Wi-SUN Alliance.
The experience in PLC and RF together with Andrea’s strategy of searching for the most convenient and cost-efficient solutions, have motivated the design of a hybrid solution. With the support of EDF R&D and ENEDIS, Andrea Informatique has created the Hybrid solution CENTAUR.
CENTAUR is strongly inspired by the G3 PLC specifications and, with respect to wireless, based on the 802.15.4g specifications. The 802.15.4g specifications are also the specifications used by the FAN profile of the Wi-SUN solutions.
The table below describes the hybrid profile for a DLMS COSEM smart equipment. The hybrid part is integrated in the MAC layer. Indeed, there are two independent parts: the PLC real time MAC and the RF real time MAC, both controlled by the Hybrid switching function on top of them.
The Hybrid switching function has many tasks, and the most important one is to send the first communication request to a node through the PLC and RF channels. After receiving the tone map response over both channels, it is decided which is the best one for creating the association-link. The decision algorithm considers several parameters before making the best choice. Then, after the second sending, the algorithm knows what is the privileged channel. The selection process is done again when problems are detected in the link or after a defined time. If communication is bad, the information is
sent in both channels.
CENTAUR is a real and interesting answer to the inconvenience of the existing PLC mesh networks (low impedances and to strong domestic noise), and also to the existing RF mesh networks (interferences and penetration of solids obstacles). CENTAUR presents a real option for increasing the reliability of the smart grid.
CENTAUR is based on Thunder, our G3 PLC soft solution and, from the hardware point of view, the main difference is the addition of the RF transceiver. Considering the cost of these components, one can asses the total cost of the Hybrid solution. From the software point of view, the differences are more consequent, but all the code is running on the
application microcontroller. CENTAUR is a soft modem. It is integrated in the application microcontroller and has two transceivers.
CENTAUR fills the gap between both PLC & RF technologies and allows interesting cost-efficient business models.