Even if regulatory and legislative action was not pushing utilities to implement advanced metering infrastructure (AMI), the business case for rapid adoption of smart metering is overwhelming. As the critical link in the emerging smart grid, AMI’s twoway communications link enables valueadded services that will benefit customers and providers. As just one example, noted on Metering.com earlier this year, http:// www.smart-energy.com/node/10977, industry analysts forecast that up to 40 percent of all customers in the USA are likely to have some kind of advanced metering by 2012, with about a third of these customers opting for flexible pricing options such as time-of-use tariffs.
A major challenge in fulfilling the expectations set for AMI and related smart grid infrastructure involves network protocols and connectivity. Cellular-based approaches may scale to appropriate levels, though a system that shares infrastructure with a network optimised for voice and mediarich data raises issues of complexity and cost. Fortunately, a key element of the network infrastructure for smart meter deployment fell into place in the last year, with the standardisation of low-power radio frequency (RF) networking based on Internet Protocol v6 (known as 6lowPAN). Equipment providers and integrators serving utilities can now look to the world’s best known networking protocol as the basis for AMI networks.
A good analogy for the state of network technology for smart metering is the computer networking environment as it existed 20 years ago. Many different islands of computer networks used protocols such as SNA, IPX, and others. When these islands were connected, it was via complex multiprotocol gateways. Skip ahead to today, and the end-to-end Internet Protocol (IP) architecture is omnipresent in computer networking. In light of its proven flexibility, stability and scalability, the enormous body of knowledge built around IP can now be applied to create the utility grid infrastructure for the 21st century.
One reason why IP has only recently won wide consideration in the smart grid network infrastructure is a misconception that the protocol was a “heavyweight”, requiring signficant computing power and memory to run in the constrained environment of a metering infrastructure. My company, Sensinode, was one of the first to provide IP stacks (the basic operating software) running on simple 8-bit processors with memory requirements of 50 kb or less. Our stack served as the basis for early work by the Internet Engineering Task Force (IETF) in the working group responsible for the 6lowPAN standard: http://www.ietf. org/html.charters/6lowpan-charter.html. The working group has defined an IP-based protocol for data communications using low-power IEEE 802.15.4 standard RF devices. This industry standardisation has opened the door to a low-cost, high-reliability and nearly infinite scalability smart meter networking.
As work on the standard is finalised, a second organisation has taken on the task of raising the market profile of 6lowPAN and establishing criteria for assuring device compatability and interoperability. Formed in August, 2008, the IPSO Alliance (Internet Protocol for Smart Objects) includes blue-chip technology and utility providers, innovative start-ups, and integrators. Familiar names on the founding members’ list includes Cisco, Duke Energy, Électricité de France, Sun Microssystems and many others: http://www. ipsoalliance.org/
Geoff Mulligan, chairman of the IPSO Alliance, described the group’s mission this way: “In recent years IP has emerged as the most efficient and scalable networking technology, not just in the traditional IT realm but in scenarios with low power, restricted memory, rugged surroundings and tens of thousands of often unattended devices. Users are recognising that the proven, ubiquitous IP standard is a much better alternative to using a patchwork of proprietary protocols that have no guarantee of scalability or interoperability, and require complex gateways that are difficult to deploy and manage. The aim of the Alliance is to provide the community with more information on Smart Objects and the industries and markets where they play an effective role. We will offer case studies and white papers, track IETF and other standards, and organise demonstrations and interoperability events.”
With standards in place and growing industry support, utilities ready to move to test and rapid deployment of 6lowPAN based network infrastructure can look to several suppliers offering solutions of varying maturity. Sensinode, which was the first company to release both an open source and commercial 6lowPAN-based software stack, has moved on to Release 2.0 of the key technologies needed to implement IP-based AMI solutions.
This past September, at the Metering Europe 2008 Conference in Amsterdam, Sensinode announced and demonstrated a complete AMI connectivity solution. The solution consists of the next generation NanoStack™ 2.0, the new NanoRouter™ 2.0 wireless Neighborhood Area Network (NAN) router and the advanced NanoGateway™ 2.0 for MBus. This latest release of our technology was developed to support smart object applications using both 2.4 GHz RF and the utility industry standard 868/915 MHz (Europe/America) RF technology. The low-power, MHz-range frequency extends the useful range of the 6lowPAN network to at least one square kilometre in urban environments. This supports the deployment of wireless mesh networks for connectivity of smart meters, with a dedicated router in each grid area providing an Internet link to the utility (Illustration 1).
NanoStack 2.0, the new release of Sensinode’s fieldproven communication stack for IP-based wireless sensor networks, is platform and radio independent. This gives chip manufacturers, OEMs, systems integrators and solution providers a fast, easy and cost-efficient way to implement the open standard in innovative low-power mesh solutions on inexpensive radios. Key features include the industry’s best code footprint, as little as 32 k of flash, extreme robustness, and the potential to support customer applications on the same processor as the IP-network stack.
NanoRouter 2.0 is a gateway router solution (consisting of both leading edge software and performance optimised hardware) between IP-based 6LoWPAN low-power wireless networks and backbone IP networks. NanoRouter 2.0 offers scalable, reliable and seamless connectivity between Internet and wireless sensor networks. Key features of the NanoRouter family include Ethernet and Power-over-Ethernet support, multiple 6LoWPAN radio support, long-range radio performance and end-to-end IPv6.
NanoGateway 2.0 for M-Bus is a gateway solution for the European meter reading standard (EN 13757) that connects previously point-to-point M-Bus devices seamlessly into the larger IP-based AMI mesh network. NanoGateway 2.0 for M-Bus increases the flexibility of wireless M-Bus and provides utilities with an easy-to-implement and efficient way to extend their networking solution with mesh technology. Key features of the NanoGateway 2.0 for M-Bus include 868/915 MHz and 2.4GHz support, 6LoWPAN networking and interoperability.
An IPSO Alliance White Paper defines the scope of the Smart Object revolution. “Smart objects enable a wide range of applications in areas such as home automation, building automation, factory monitoring, smart cities, structural health management systems, smart grid and energy management, and transportation.” As utilities consider the future application of smart meters, particularly the linkage of the meter to in-home and in-commercial/industrial building networks, the value of an end-to-end IP-based solution is clear.
In a mid-2007 report, the US Federal Energy Regulatory Commission (FERC “2007 Demand Response and Advanced Metering” staff report) estimated that up to 40 million AMI devices would be shipped by early next decade, representing a significant, but still minority, fraction of the estimated 130 million meters now in the US. Clearly, adopting a network technology today that can scale to hundreds of millions of connected nodes will be an important part of a successful implementation of this infrastructure.
When the next generation Internet Protocol IPv6 was defined by the IETF, the standards body already envisioned an era when hundreds of millions of smart objects would have a unique Internet address. The scalability of the network is practically unlimited, with an address space of 2128, which is considered sufficient to provide every grain of sand on earth with an IP address. This will readily support any demands that utility infrastructure will produce, with sufficient headroom for billions of additional network nodes. Additionally, experience in the computer realm has created a pool of skilled network design and administration talent, along with numerous proven management protocols and mechanisms. By leveraging this vast knowledge base, the utility industry will benefit from a 30-year history of investment and technology refinement.
Sensinode is committed to providing the network technology for the smart grid infrastructure. Building this infrastructure on IP technology with meter-to-grid wireless connectivity will deliver network scalability, reliability and affordability. Our Release 2.0 software stack, router and gateway products make this globally deployed, standardised technology completely accessible to equipment providers and integrators serving the utility industries.