Connectivity Framework
3: Connectivity Reference Architecture
K) vs. the original N *( N-1)/ 2 shown in Figure 3-1. Assuming K << N, the number of gateways goes from O( N ²) to O( N), which is much more tractable.
Each additional core standard creates increasing complexity and interoperability challenges with the square of the number of core standards. A few( small K) core connectivity standards should suffice to cover the needs of IIoT systems across the functional domains and industries to attain the goal of horizontal interoperability.
3.4 CORE STANDARDS CRITERIA
A connectivity core standard should align with the priorities on the requirements, engineering tradeoffs and ecosystems in its functional domain. It should not get in the way of providing seamless interoperability between domain-specific endpoints connected to it via gateways. This means meeting not only the functional requirements, but also the non-functional requirements of reliability, performance, scalability, availability, security and safety. Below, we define the criteria for qualifying as a connectivity core standard.
A connectivity core standard shall:
• provide syntactic interoperability,
• be an open standard with strong independent, international governance, and with support for certifying or validating or testing interoperability of implementations,
• be horizontal and neutral in its applicability across industries,
• be stable and deployed across multiple vertical industries,
• have standards-defined Core Gateways to all other connectivity core standards.
A connectivity core standard shall provide syntactic interoperability( see section 2.2). It is not simply sending opaque blobs. Applications not only get the data, but they can also discover the data types to unambiguously parse and manipulate it as structured data. So, an application will, for instance, know that the data it received is a structure with three floating-point number fields and a string field. The connectivity stack( see section 2.1) does not provide semantics— the interpretation of the fields, such as the units, ranges, and context is important for IIoT systems, but outside the scope of connectivity, and covered by the Distributed Data Interoperability and Management layer in the Industrial Internet Reference Architecture.
A core connectivity standard shall be an open standard managed by a recognized standards development organization( SDO). The SDO should provide independent, international governance. There should be support for validating or certifying or testing interoperability of implementations adhering to a specification from the SDO.
A core connectivity standard shall be stable and deployed in systems across multiple industries. It should not qualify until it has been fielded and has operational proof points in fielded systems. Connectivity standards that are not proven deployed across multiple industries or in fielded systems can be considered a common connectivity standard in one or more specific industries. We should strike a balance between leading the industry and lowering risk. We set that balance at the point of deployed applications across industries.
IIC: PUB: G5: V1.0: PB: 20170228- 25-