# SCM-IoT: An Approach for Internet of Things Services Integration and Coordination
## 3 Methodology
### Conceptual Model
Production notes contain all the necessary information to determine the page and the field addressed for the update;
* Content subscribers request notification services on specific data contained in the storage as soon as available. Subscription notes contain the unique identifier of the corresponding subscriber and the notification condition upon the storage contents the subscriber is interested in being notified of. In IoT, particularly home automation, sensors and actuators are identified respectively with producers and subscribers. Producers originate the data to update the book by intermediation of the editor. Subscribers receive notifications from the editor about the logical conditions that are satisfied with the notebook's contents. Thus, an application in IoT develops an observable behavior for the data flow, as a data flow that transits from sensors to actuators. The editor act as a broker that uses the notebooks for data reception, \begin{table}
\begin{tabular}{c c c c c c c c} \hline
**ID** & **Name** & **Presence** & **Temperature** & **Smoke** & **Toxic Gas** & **Heater** & **Cooler** & **Alarm** \\ \hline PAS & HALL & NO & NOR & NO & NO & NO & NO & NO \\ SAL & LIVINGROOM & NO & BAJ & NO & NO & NO & NO & NO \\ COM & DININGROOM & SI & BAJ & NO & NO & NO & NO & NO \\ COC & KITCHEN & SI & NOR & NO & NO & NO & NO & NO \\ REC & BEDROOM & NO & NOR & NO & NO & NO & NO & NO \\ EST & DEN & NO & NOR & NO & NO & NO & NO & NO \\ BAN & BATHROOM & NO & NOR & NO & NO & NO & NO & NO \\ \hline \end{tabular}
\end{table} 
Table 1: Room state. transformation, and further notification. SCM-IoT simplifies the scheduling of activities since the interactions between participants are generally very complex. In SCM-IoT, sensors and actuators are grouped by the topic of environmental variable they are intended to deal with. Among the topics often used in domotic applications are, for example, human presence detection, temperature, humidity, or light intensity. As shown in Figure 1, the architecture has a layered design, organized in production layer, edition layer, and subscription layer:  
* The production layer consists of relatively independent client producers responsible for generating the primary content of the storage medium. The production layer emits update note requests to the edition layer for this aim;
* The edition layer receives all the update request notes addressed by the production layer. If relevant, the notes are accepted to be posted in a field of a notebook page. The editor judges the relevance of an update request, deciding on its acceptance according to a set of rules. A simple relevance rule is that the datum in the note must differ from the one already contained in the corresponding page's field, avoiding unnecessary editor actions. The editor monitors each update, filling other fields on the same page or other pages, following system application rules. The end of the editor's activity triggers the test of the notification conditions of all subscribers and to carry out the notification to all the subscribers whose notification conditions hold;
* The subscriber layer consists of a collection of independent clients who are ultimately responsible for undertaking the necessary actions to ensure compliance with the system's overall goals. The subscribers' activities are triggered after their notification or collection conditions have been met upon the current state of the storage contents. The editor aims to preserve the consistency and integrity of the data stored in the notebook, acting as a provider of services for querying, updating, and notifying the notebook contents. The following elements characterize the evolution of the behavior of a system using the SCM-IoT model:  
* Clients carry out their activities independently of each other but indirectly interacting through the editor's storage services;
* The data flow direction differentiates the editing services in the notebook.