The X-10 powerline control system has been around for ages, but its unidirectional broadcast mode is slow and not always reliable. Still, it's extremely useful. Smarthome's new Insteon technology targets the same market but improves on the X-10 technology while remaining backward-compatible.
First, Smarthome kept the design simple. Instead of trying to take on high-speed networks like HomePlug (www.homeplug.org) or wireless 802.11, it uses a slightly higher frequency and modulation technique to send data at 1200 bits/s versus X-10's 60 bits/s. This enables the Insteon protocol to include 48-bit source and destination addresses, unique to each device, as well as a cyclic redundancy check. Encryption can be supported, so the technology can be used in security applications.
Second, Insteon employs a repeater-based protocol. In some installations, an Insteon node such as a switch may only communicate directly with a subset of the other nodes in the network due to problems like attenuation. Nodes farthest from the source repeat the message. Increasing the number of nodes in the network expands the network's coverage. X-10 sources can also use this feature by having an Insteon node handle the repeater support. Wireless repeaters will be available.
Finally, Insteon devices know about X-10. Outgoing messages are quickly sent using the Insteon protocol and then using the slower X-10.
Smarthome will make the controller chip available to developers. The company is actively courting appliance manufacturers and home builders to incorporate Insteon technology within their products. Insteon is smaller, faster, and more reliable than X-10. At the same time, the technology is oh so compatible.