Smart Meters

The home’s Smart Meter will most often be the energy services gateway. It interfaces with utility infrastructure via a wide area network (WAN) connection and electric loads within the home’ area network (HAN). In Smart Grid parlance, a device acting in this role is the energy services interface, or ESI. In addition to providing energy measurement functionality, the smart meter/ESI is essentially a bridge between the WAN and the HAN and performs a crucial bridging function in an extensible IP-based network.

Multiple Communications Interfaces for Smart Meters

The Smart Energy Profile 2.0 (SEP2) is a networking and application integration platform for messages between customer devices and energy service providers. SEP2 was selected last year by the U.S. Department of Energy and the National Institute of Standards and Technology (NIST) as an initial interoperable standard for HAN devices and is being developed to run at the application layer above the IPv6 stack. It will describe all of the requisite energy management message structures and formats, and will also support robust security capabilities that are essential to reliable Smart Grid operation. The figure above depicts a functional partition for a smart meter. Note that SEP2 and the IPv6 stack are both supported on the main processor board rather than on the various MAC/PHYs.

The functional partition depicted above offers the distinct advantage of using a common IPv6/SEP2 stack across all supported MAC/PHYs. Next-generation smart meters will support both WAN and HAN interfaces. In some cases, more than one HAN interface will be used. There may be two (and in some cases three) separate MAC/PHYs included in a Smart Meter. Supporting IPv6/SEP2 on each MAC/PHY would be redundant and would complicate interoperability issues.

Qualcomm Atheros offers a variety of low-power Wi-Fi® and HomePlug-compliant powerline solutions for smart meters, and supports the emerging HomePlug Green PHY specification for low-energy operation. Both HomePlug and Wi-Fi use standard IEEE 48-bit MAC addresses and will integrate seamlessly with IP-based networking stacks.