Cisco, Silver Spring Networks and many others want to bring IP communications to the wireless smart grid, but what about the wired smart grid? Powerline communications — sending data over the same wires that carry electricity — is now accomplished through a welter of different proprietary technologies, and one of them will soon get more open. German engineering giant Siemens said last week it would open up its proprietary Distribution Line Carrier protocol for low-voltage powerline communications in January 2011, in hopes of allowing other vendors to interoperate with its metering technology known as AMIS. Other low-voltage powerline communications systems include those from smart grid and building controls vendor Echelon Corp. and the HomePlug Powerline Alliance. Still, none are as far along in end-to-end IP compatability for powerline communications as Cisco says it will be with the wireless technology it’s getting with its acquisition of Arch Rock.