Routing Protocols for Power Line Communication (PLC) by Darrin McIntyre
Little guys IEEE 1675-2008: standard for BPL developed by the IEEESA. Provides electric utility companies with a standard for safely installing hardware required for BPL capabilities over their power lines.
IEEE 1905 Allows networked devices in the home connected by different network media to operate as if they were connected across the same medium. Supports Ethernet, Wi-Fi, PLC(BPL), and co-ax cabling using the Multimedia over Co-Ax (MoCA) specification Convergent layer, focuses on discovering what each device is capable of and looking for the best way to output the data received.
IEEE 1901 Two different physical layers, First, based on FFT OFDM modulation Second, based on Wavelet OFDM modulation Each Layer is optional and implementers are not required to include both FFT layer is derived from and deployed in HomePlug-based products Includes a forward error correction (FEC) scheme based on convolutional turbo code (CTC). Wavelet layer is derived from HD-PLC technology and is deployed in HD-PLC based products. Includes a required FEC based on concatenated Reed-Solomon (RS) and convolutional code, and an option to use LDPC code. On top of these two physical layers, two different MAC layers are used. Two MACs were needed because each application has different requirements. In-home networking will network machines within a building. Access BPL will carry broadband internet using power lines and allow power companies to electronically monitor power systems. To manage coexistence between the MACs and physicals the ISP (inter-system protocol) was developed ISP enables various BPL devices and systems to share communication resources (like time or frequency) when installed in a network with common electrical wiring. Allows 1901-compliant devices and ITU-T G.hn compliant devices to co-exist. ISP provides configurable frequency division for the Access MAC layer. Provides time division for in-home with a granularity compatible with QoS even for highly demanding applications.
IEEE 1901 – Adoptions International Telecommunication Union (ITU-T G.9972): The IEEE 1901 ISP coexistence protocol has been extended to support networking standards of ITU-G.hn. The Smart Grid Interoperability Panel (SGIP): Mandates the implementation of IEEE 1901 ISP in all technologies operating over power lines Digital Living Network Alliance (DLNA): Standard for Digital Home Networks. SAE and IEC 62196: standards for electric vehicle charging include IEEE 1901 as the standard for power line communication between the vehicle, off-board charging station, and the smart grid. IEEE 1905.1
Challenges High-voltage power lines are the first obstacle. The power flowing down high-voltage lines is between 155,000 to 765,000 volts. Both electricity and the RF used to transmit data vibrate at certain frequencies. Must have a dedicated band of the radio spectrum at which to vibrate without interferences. Hundreds of thousands of volts of electricity don't vibrate at a consistent frequency. This causes interference. BPL avoids high-voltage power lines all together. The system instead uses traditional fiber-optic lines until a medium voltage line is available (7200 volts or less). Degradation is another issue with this technology. Repeaters take in the data and repeat it in a new transmission at points along the path. Transformers are another issue, they would destroy the signal as it passes through, it is used for reducing the 7200 volts down to 240 volt standards for household. The CT Coupler allows the data on the line to bypass transformers.The coupler takes the data out of the medium voltage line and puts it into the 240 volt line without any degradation. Encryption is an important factor. 128 bit AES encryption is used, without encryption intercepting data would be extremely easy. Repeaters can help to implement this encryption.
Future Potential to communicate with all house-hold objects that are plugged in (EX: alarm clock turns on coffee maker). Only about 34.3% of the world has internet access while about 77.6% has electricity. This could more than double the about of people in the “digital loop” so to speak. Because of its low cost, could create a lot of price competition among other providers. BPL technology could be used to assist the utility companies by adding intelligent capabilities to the electric grid, thereby improving efficiency in energy management, power outage notification and automated meter reading.
Referrences • http://www.scribd.com/doc/42364138/Broadband-Over-Power-Line • http://www.internetworldstats.com/stats.htm • http://data.worldbank.org/indicator/EG.ELC.ACCS.ZS/countries?display=graph • http://www.businesswire.com/news/home/20120313005016/en/DLNA%C2%AE-Approves-HomePlug-AV-HD-PLC-Powerline-Networking • http://computer.howstuffworks.com/bpl.htm • http://www.theregister.co.uk/2013/02/15/feature_wtf_is_ieee_1905_dot_1/?page=1 • http://www.theregister.co.uk/2013/02/15/feature_wtf_is_ieee_1905_dot_1/?page=2