Technology

Powerline Communication (PLC) is a method of communication using a communication channel current energy distribution LV (low voltage). The ability to transmit data messages using the existing power distribution system as a communication medium provides a new impetus for the development of applications in industrial automation, integration and other communications solutions. PLC technology has enabled dramatic cost reductions in areas requiring communication between system components, for reasons of eliminating the cost of communications infrastructure, ie the purchase and installation of cabling for communication.

Modern PLC technology overcomes many disadvantages stemming from communication in the existing energy distribution. First of signal attenuation, which is directly dependent on the frequency. This attenuation is not constant over time. Another drawback is the high noise they generate back into the appliance itself. Existing EU legislation allows for the use of PLC transmission frequency range from 3 kHz to 148.5 kHz. PLC communications ModemTec are compared according to the available supply currently the world's most advanced technologies for narrow-band communications in the electrical distribution system. ModemTec PLC technology to reliably communicate over existing power distribution at the distance of 5 km.

The basic principle of the PLC communication modulation and demodulation. The power voltage, or power distribution is imposed modulated RF. signal that propagates along this line. The signal is superimposed on the existing power supply. The receiver module is separated from the power supply signals in the communication zone and detecting the resulting signal is obtained original data. Because the data are affected by interference must verify their accuracy. This is done by the CRC checksum. In other words checksum calculation to find out from the received signal must agree with the checksum that was calculated in broadcasting and is part of the received data. The next step to improve the resilience of communication is the use of FEC correctors that add redundancy to the transmitted data information from which the signals and fault data is able to restore the original data. To increase the security of transmitted data using other techniques such as repetition, confirmation messages transmitted, or 100% redundancy broadcast messages, the interleaving of the broadcast and rebuilding in receiving.
Another important part of the transmission reliability is the knowledge of the network topology, energy and signal attenuation depending on the modulation frequency and the local disposition. 

ModemTec company managed to achieve that in the area fed by one source (and thus the length of the energy distribution is affected by voltage drops) we are able to transmit information, and in most cases from the concentrator to the end point without having to insert repeaters (difference over broadband PLC transfers, you must use a repeater every 50 to 100 meters). Both groups modems can operate in the field of terminal equipment without special modifications.

ModemTec company managed to achieve that in the area fed by one source (and thus the length of the energy distribution is affected by voltage drops) we are able to transmit information, and in most cases from the concentrator to the end point without having to insert repeaters (difference over broadband PLC transfers, you must use a repeater every 50 to 100 meters). Both groups modems can operate in the field of terminal equipment without special modifications.

Parameters communicating modems are verified by long (several years), and both pilot projects, as well as routine monitoring of projects. Site selection of pilot projects focused on different environments LV power distribution system. Although these projects have shown that there are two completely identical locations, the company was able to prepare a working procedure for the implementation of PLC transmission in any environment. Based on practical experience, each equipped with internal modem diagnostics which are used both to analyze the behavior of the modem and then also to analyze the transmission path.

Security
If we talk about security, many people think about soft ware (program and data) security only. It means they explore possibility of successful cyber-att ack against program in the devices, or changing some data. 
It is solved by the most advanced encrypti on methods (AES256), or by digital signature (ECDSA-P256) at secured data, and by asymmetric encrypti on for the key exchange (ECDH-P256), according to National Security Agency (NSA) recommendation. And what about the security of hardware? Usually, various tampers (sensors indicating e-meter opening) are used. Unfortunately, such a solution is easy to bypass, and e-meter welding is not appropriate. 
That is why, ModemTec uses both, basic security, and advanced techniques for security against breaking into the devices. We talk about making the hardware break significantly difficult due to multi -layer printed circuit board (PCB) usage, placing components at hardly reached places, special tampers at PCBs, BGA packages (pins are situated under the component and go towards to PCB without any possibility of contact - approach to the terminals and signals is excluded). Moreover, the advanced HW self-diagnostics make our devices very resistant, which is hardly to attack in such a way that customers (utilities) do not find it out.

High Voltage Communication
Power line communication (PLC) that uses low voltage power network proved its legitimacy in many aspects. Costs for communication channel development are minimized, maintenance of data channel and devices is independent on the third parties, and last, but not least, data transfer volumes and associated costs in comparison with public operator are much more convenient. 
It thus seems, that next logic step is a transfer of PLC technology into data channel realized by high-voltage (HV) and extra-high-voltage (EHV) power lines. Such a solution means that low-voltage distribution substations (with data concentrators communicating with e-meters of end-customers) are mutually connected and can transfer information for devices placed at these substations. Data service for devices supporting HV and EHV distribution system belongs among further task of this type of communication. If we face to the requirement of 100% coverage for communication interconnection between these devices, PLC technology seems to be the only one which can ensure it. 
HV communication is one of the basic pillars for the Smart Grid development.