Architecting the Smart Grid Using the Industrial Internet of Things
model, communication pattern, and quality of service (QoS) parameters like reliability, data rate,
or timing deadlines. While connecting two systems is a challenge, it is solvable with a specialpurpose “bridge”. Nevertheless, it does not scale; connecting N systems together requires Nsquared bridges. As N gets large, connecting them all becomes untenable.
One way to try to solve this “n-squared” problem is to dictate the standards to use in each of
these areas (protocol, data model, communication pattern, etc.) This is the approach taken by
Industrie 4.0. The issue with this approach is that it is impossible to cover all system types and
needs in a single standards stack. Industrie 4.0 addresses this in its focus on manufacturing. The
IIC’s ambition is to address multiple industries.
At the other end of the spectrum are specialized bridge points like “Enterprise Service Buses”
(ESB). ESB’s like Apache Camel use the word “bus,” but they are fundamentally not a distributed
concept. Instead, they provide bridging between multiple connectivity frameworks, so all
systems have to connect to the ESB and translate to its core connectivity bus. Currently, ESBs are
focused on enterprise software system integration and are generally implemented as a central
service. Most are not open standards or architectures either.
The IIRA takes an intermediate approach to provide a “Core Connectivity Standard”. Unlike an
ESB, the core connectivity is itself a connection standard to which devices and applications
attach. Other devices and applications connect through “gateways”. The core standard then
connects them all together. This allows multiple protocols to co-exist, without having to bridge
between all possible pairs. Each needs only one bridge to the core (See Figure 2).
Figure 2. The Connectivity Framework in the IIC’s Industrial Internet Reference Architecture calls
for a core standard connectivity bus with gateways to bridge to existing devices and protocols
streamlining interoperability and security.
IIC Journal of Innovation
- 21 -