Internet of Things Architecture

request, the response might take longer time to be delivered and, in the

worst case scenario, it may get lost;

2. Web only: No local copy is maintained by devices. As soon as data is
   sent to the aggregator, they are dispatched in databases;


3. Local with web cache: A hierarchical structure for storing data is
   maintained from devices up to database servers.

Finally, one of the core features of IoT systems is the resolution of services and
entities, which is provided by the Entity and Service Resolution FCs,
respectively and is in charge of semantically retrieving resources and services,
discovering new elements and binding users with data, resources, and services.
In particular, this is performed adopting the definitions of the Virtual Entity FG.
This choice, while one of the most important for the designer, has only two
options:

1. Internal deployment: The core engine is installed on servers belonging
   to the system and is dedicated to the target application or shared
   between different applications of the same provider;


2. External usage: The core engine is provided by a third party and the
   system designer has to drive the service development on the third party
   APIs.

Differently from the other choices, this is driven by the cost associated to the
maintenance of the core engine software. In fact, since it is a critical component
of the system, security, availability and robustness must be enforced. Hence, for
small enterprises the most feasible solution is the external one.

4.2.4.1 Deployment example

Coming back to our ―Red Thread‖ example, this section analyzes the system
deployment for the ―Transport monitoring with Smart Load Carriers‖ scenario.

First of all, we need to define the purpose of the application(s), the
functionalities and their requirements for a correct operating behaviour and the
data that needs to be treated.

Purpose: the application measures several environmental parameters of the
load carrier such as the light, the temperature and the humidity of the truck and
monitors the status of the several installed devices.

Functionalities:

 Monitoring: the application needs to provide the users with means to

access information gathered by many sensors installed in the truck;

 Controlling: the application needs to provide users with means to modify

the behaviour of the many installed devices;