Gigle Networks discusses powerline networks
Andy Melder, VP at Gigle Networks talks about the evolution of power-line communications as an alternative to WiFi and Ethernet for home networking on an IP-based protocol. In the past, power line networking was restricted to simple command and control functions like turning on lights and small appliances. The difficulties were in the pervasive noise and the resulting poor signal quality.
The biggest issue the power line communications equipment must address is noise. Electrical systems are connected to motors, fluorescent lights, etc. all of which generate lots of noise as power spikes, line drop-outs, and medium bandwidth noise. The latest (wireless) communications have overcome channel noise by using techniques like frequency hopping, multiple signal per bit encoding, and complex carrier modulation schemes. Together, these innovations have enabled data transmission over relatively noisy channels.
As a result of the improvements in signal processing, the noise issues are now relatively well addressed. The breakthroughs in signal processing, communications protocols, and device integration advanced the state of the art to allow for high bandwidth data communications over power lines—resulting in the advent of HomePlug AV.
This new set of systems is covered by a draft standard from the IEEE. P1901 enables 200 Mbits/sec data transfers over power lines. Some major companies are involved in the standards work for P1901 which has just finished the comments stage. Final balloting is expected in Q3 of this year. The IEEE working group P1901 includes semiconductor vendors, systems companies, the HomePlug Powerline Alliance, Consumer Electronics Powerline Communication Alliance (CEPCA), with some additional inputs from the government’s smart grid organization.
The alliances include device makers, AV products manufacturers, and utility and cable companies. Together, these organizations and companies have assembled a working standard that enables broadband data communications over internal house wiring.
The soon to be released standard addresses one of the greatest challenges for power line communications, the installation and troubleshooting of the network. The components must be installed without consumer intervention to be accepted by those who are not rocket scientists or network managers.
This is an issue for the service providers as well as the component manufacturers, since people don’t really want the power company to come into their houses and try to install or fix a Homeplug system. The operators cannot manage the networks but must be able to deliver high quality of service and ease of use. An issue for the power companies is a perceived lack of domain expertise and a relatively poor customer service image. The cable companies have similar issues while also being responsible for much of the content.
The standard, that is soon to be released, delivers a robust data network infrastructure. P1901 is going into testing in about 2 months. The newest technologies and protocols overcome the noise issues and seem to operate across multiple breaker boxes. Homeplug 1.0 is now relatively noise free. Even though all communications technologies can be jammed, the new products appear to be worthy of consideration as an alternative for WiFi and cable systems. By using the power lines, you don’t have dead spots in your RF coverage and don’t have to pull new wires into an existing building.
Homeport AV addresses these issues for home networks over power lines by adding enhanced network management capabilities. The spectral region for the Homeplug systems uses 2-30 MHz over the power line. In general, this system works for simple single breaker box sites, and doesn’t need bridging across multiple breaker boxes. In enterprise environments, the use of multiple transformers and breaker boxes with no known phase relationship across the subsystems is a difficult challenge. The challenge in creating the network is that the signals cannot easily hop across the different power zones or power loops from different breaker boxes. An important issue that the equipment for the home network over power lines must overcome is the cabling and other infrastructure.
By adding network processors and network flow management, the new Homeport AV solution can address the issues of quality of service and fixed latency needed for video transfers. This is a significant change in components for the component manufacturers. The latest implementations have integrated intelligence to aggregate data streams and manage the automatic network configuration. These networks include meshing for repeaters and end points.
Gigle Networks started in Spain as DS2 in wireline comms. They developed the PHY, MAC, and a network management structure for their chips. In ’06, founded and funded as Gigle Semiconductor. Their main product is a home-plug transceiver similar to WiFi with a 200 Mb/s backbone function. Their implementation has a second channel above the standard home plug spectrum that increases the throughput to a Gb/s. Their architecture uses a superset of existing technologies for QoS and reduced bit error rates and can combine Wifi and power line channels.
Their devices are ready to be tested to the upcoming standards. The MAC is a soft MAC that can handle any protocol changes since it can be updated in the firmware. The design allows for firmware updates in operation, so any future changes in the MAC can be addressed on the fly.
