Renesas Electronics Launches PLC Solution for Voice Communication Over Power Lines
Tokyo, Japan, September 13, 2017 - Renesas Electronics Corporation (TSE: 6723), a premier supplier of semiconductor solutions, today announced the launch of a new voice power line communication (PLC) data communication and voice communication.
A PLC solution reduces the amount of wiring inside a building, thereby reducing the cost of implementing and maintaining public address (PA) systems and security systems.
The new solution consists of a Renesas PLC software modem (R9A06G037) that manages PLC communications and an RX651 microcontroller (MCU) that controls audio codec processing.
The new solution enables system manufacturers to enhance security systems by integrating voice capabilities into existing installations at low cost. For new installations including various sensors and voice communications, wiring costs can be reduced by about 60%, while installation and maintenance costs can be reduced by up to 40%.
Facilities such as office buildings are installed with various management systems including climate control systems, lighting, various sensors, building public address systems and security systems.
In the past, each system required its own dedicated line. Recently, the trend has been towards utilizing existing direct current (DC) power lines in configurations where these communication lines are shared with the power system.
However, attempts to use powerlines for voice communication have resulted in poor audio quality due to fluctuations in latency. To solve this problem, the new voice PLC solution uses priority control during audio transmission to virtually eliminate delay fluctuations in voice communication, even when signal control communication and voice communication operate on the same power line. This ensures that the audio quality remains consistent at all times.
In addition, the solution optimizes the audio priority control function with Renesas' narrowband PLC technology, enabling the use of signal lines longer than one kilometer without the use of repeaters. By combining data communication and voice communication on the existing electricity network, the new solution can significantly reduce the amount of wiring required for building management systems and help reduce maintenance costs.
Main Features of Voice PLC Solution
Realize priority control in audio transmission, suppress delay changes, and ensure stable sound quality
In a PLC system, multiple devices use power lines as a common communication medium, so data collisions must be avoided. This is similar to the anti-collision feature used in wireless communications where data is transmitted after confirming that no other device is communicating.
Renesas' voice PLC solution utilizes an optimized anti-collision function to give priority to devices performing "voice" transmission. This minimizes fluctuations in communication latency and ensures stable voice communication without interruption.
Supports long-distance transmission of more than one kilometer without relays, enabling extensive coverage within each unit
PLC systems often include repeater (hopping) mechanisms to extend distance coverage.
However, these mechanisms also lead to increased fluctuations in the data transfer process. The R9A06G037 PLC chip integrates an analog front-end circuit with a wide dynamic range for transmission and reception, a variable amplifier, and ADC and DAC peripherals. In addition, Renesas has increased the operating frequency of the DSP used to perform PHY layer processing and added special instructions for PLC processing.
These enhancements enable greater sensitivity to extremely small signals and better immunity to noise generated by power lines, enabling long-distance communications. The new Voice PLC solution has been tested and proven to support over 128 node connections over a kilometer long DC power line without the use of repeaters.
Easy-to-implement software stack reduces time required for system development
The new solution is paired with a flexible and configurable software stack running on the Renesas RX651 MCU. The software stack allows users to easily select and implement an audio codec with the desired characteristics, greatly reducing the time required for system development.
