12-1 Why a single data model is key to the success
Introduction
The IEC 62056 DLMS/COSEM series of standards developed by IEC TC 13 and supported by the DLMS User Association provides a consistent standardization framework for smart metering. The gist of this framework is to use a single, communication media independent, object-oriented data model that can be used over a wide range of communication media, and allows achieving interoperability on the end device level.
In the smart metering / smart grid context, standardization became essential to remove market barriers and to facilitate large scale rollout at lowest cost.
Consequently, some technologies that have been kept proprietary before are proposed for standardization. Those technologies come with their own data model creating a conflict with the established standardization framework and jeopardize the consistency of standardization.
For some other technologies proposed, only the communication media dependent lower layers are specified. These technologies can be readily integrated into the IEC 62056 framework.
This situation offers two options for handling new standardization proposals, as illustrated in the Figure below. The purpose of this paper is to provide arguments supporting the IEC 62056 framework and for consistent standardization.
Right hand side of the figure above:
Each new communication technology is integrated into the IEC 62056 framework, using ONE standard data model and ONE set of data security tools. This is a consistent approach in that:The data model (use case dependent) and the communication protocols (technology dependent) are separated;
The object oriented data model specifies how the various use cases can be supported and how the model can be extended to support new use cases;
The lower layers provide maximum flexibility to support a range of existing and upcoming communication media.Left hand side of the figure above:
Some standards proposals are “Self-contained” specifying both the lower layers and data models. These proposals are in conflict with the existing standard and also with each other. Their promoters argue that interoperability could be achieved on higher levels of the system, so inconsistency on the device level is a non-issue.
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