Fig. 8. Response times for scaling a payload size.
Limitations and lessons learnt
The use of the CIM in the context of the DELTA project demonstrated to the authors that semantic interoperability modules appear to be a viable way for performing uplifting and down-lifting instead of adapters (which are non-reusable pieces of software). However, the authors have observed that developers frequently create ad hoc solutions for Uplifting while ignoring Downlifting. As a result, while interoperability modules appear to be a reasonable technology solution for achieving semantic interoperability, greater distribution is required, and developers must be educated to design and utilize them.
From the experimental part and the DELTA pilots’ implementation. The authors discovered that in some circumstances, particularly in high-latency settings, the time necessary to complete a data exchange was insufficient. The authors investigated the cause of this disadvantage and determined that XMPP networks are not the quickest alternative. However, this is not a significant drawback because it is fast enough for most DR circumstances. Nonetheless, for other cases, such as DR with electric vehicles, new peer-to-peer systems should be investigated.
Furthermore, whereas DR often necessitates live data and signal transmission, payloads are typically small. However, certain DELTA project pilots needed the transmission of previous data. These huge payloads are unsuitable for XMPP networks. For this specific situation, the answer in the project was chunking the data; nevertheless, in circumstances where there is a definite requirement to exchange huge payloads, XMPP is not an appropriate technological choice.