The PLC (Power Line Communication) which uses power lines, is receiving a lot of attention as the simplest technology to realize an ‘Ubiquitous’ society, a society where anyone can connect to the network. In September of 2007, ‘HD-PLC Alliance’ was formed to promote and improve the compatibility of HD-PLC, a PLC system that originated in Japan. Not only is the alliance promoting the widespread use of PLC, but it is also heading the movement to set up an international standard. What does the alliance envision for the future of HD-PLC after its widespread use is established? Eiji Kobayashi, CEO and President of HD-PLC Alliance, shares his thoughts in this two-part interview. The following is Part1 of 2.

•——What exactly is PLC? What kind of technology is it? What kind of advantages will it offer to users?

• Actively promoted HD-PLC at international exhibitions. Pictured is the booth at CES, held in January 2008 in Las Vegas

Kobayashi: In a word, it is “communication using power lines”. It is a technology that connects electronic equipments all over the house using power outlets that are already in use in any household or room.

Not just PCs, but all types of electronic equipments such as televisions and game consoles are becoming internet-ready. However, to connect them to the internet, cables may run all over the house, setting up the connection up may be troublesome, or it may be that you have to use wireless LAN, which may or may not work depending on the structure of the house. With the widespread use of broadband such as ADSL and FTTH, high speed connection is right at the users’ fingertips, but has escaped their grasps, just inches from the electronic equipments they want to connect to.

PLC is a technology which connects equipments to the network using power lines by layering high frequency signals used for data transmission over existing power lines. Just by plugging into a regular power outlet via a PLC-capable device, users will be able to connect to the internet. No need for complicated setups or construction. Globally, there are three types of communication systems to PLC. There is movement to set up an international standard, and HD-PLC is at the center of the movement.

Realizing High Performance with Ease

•——What is the feature of HD-PLC?

Kobayashi: One feature is that ‘Wavelet-OFDM’ is used for modulation and demodulation to transmit data, which is a method with a high capacity of frequency sharing. When a large amount of data is transmitted in a short time, the transmission may not be completed properly due to interference, for example. The ‘Wavelet-OFDM’ system can solve these problems. As a result, a high level of performance is now possible; audio files and video can be sent at 210 Mbps (PHY rate).

Various home electronics are connected to the power lines, which interfere with the performance of PLC. It is necessary to constantly pay attention to the source of the interference. By adjusting the timing and the amount of data sent at high frequencies, data transmission can be done efficiently, while maintaining the high speed.

One other feature is the ‘AES(Advanced Encryption Standard), an encryption technology standardized by the U.S. government. Highly secure at 128-bit encryption, it can be set up easily with a press of a button. Some wireless LANs cannot be connected correctly because of the difficult security settings, or worse on PC, some users are using wireless LANs without any security in place. Because setting up wireless LANs is a little difficult for people without specialized knowledge, other equipments which can be connected to the network may be left untouched, as the users give up. It is also difficult for manufacturers and stores to support those users. HD-PLC can be set up as easily as any other home electronics in the home. I believe that the time will come, given that the security is assured, users will connect all kinds of home electronics to the network, where as now it is not only limited to PCs and TVs.