The other day we had an interesting debate about whether IPv6 is a red herring in the design of todays Advanced Metering Infrastructure (AMI) solution. We covered some interesting points that I want to summarize here and in the next few blog posts.
The day the first electricity meter was installed the business problem of collecting meter readings was created. Over the years the ability to collect meter reads remotely has evolved using both wired (e.g. Power Line Carrier or PLC) and wireless radio (e.g. radio frequency mesh) networks that enabled one way and then two way communications.
Figure 1 - High Level Network overview
In the past (and in many cases today) purchasing a meter vendor’s smart electricity meters required installation of that vendor’s Head End System (HES) to manage all communication with those meters. Beyond the Head End System in the diagram above the network of meters is opaque – the meters are not directly addressable.
In the early days of AMI deployments this wasn’t seen as too much of a hindrance. At the application layer everyone just used application identifiers like Service Delivery Point ID that the HES could then map onto the closed meter network.
However, as AMI deployments have matured the network technology limitations imposed by a closed, proprietary meter network have become more relevant.
Interoperability has started to change things
Distribution and Supply companies around the world realized some time ago that the historical tight coupling of a vendor’s meter communications to a specific HES implementation presented challenges and costs. As an example, a multiple meter vendor strategy brings along with it the installation and operation of the corresponding HES’s.
Regulatory and market pressure (particularly in the European Union) has incented meter vendors to develop arrangements where one agrees to build support for the other’s meters in to their HES and to start supporting more open, standards based network technologies – including IP.
So why didn’t open, standards based protocols like IP get used from the start?
An answer (and there are many…) is that the initial implementations of the wireless radio or wired power line segment of the overall AMI network had very limited and fragile bandwidth. It was felt that the overhead that comes with protocols like IP would be an unacceptable drag on throughput.
A second answer would point to meter vendors protecting what each regarded as an important competitive advantage in their specific meter communications solution.
A third answer would be the security advantage (however dubious) of using a protocol that is not in the public domain.
Why is the focus always on IP and not some other open standard?
This question was a topic of intense debate but is, for all intents and purposes, decided. The industry voted with its dollars and almost all new AMI products – particularly networking gear – sport the “Supports IP” feature.
A note of caution here – many people in this debate have confused IP with TCP/IP. You can find a good description of the differences on Wikipedia but suffice to say that many of the internet protocols people are familiar with like FTP, SNMP, SSH, HTTP, etc. are connection oriented and use Transmission Control Protocol (the TCP in TCP/IP). Our friend IP is only interested in moving the data around – essentially address resolution and routing.
In the next article in this series we’ll take a look at some of the arguments in favor of IPv6.