Читать книгу Service Level Management in Emerging Environments - Nader Mbarek - Страница 40

The device layer of the IoT architecture includes connected objects and gateways that manage these objects. The QoS at this level must, therefore, respond to requirements with respect to objects and gateways.

An essential requirement for ensuring QoS in the device layer is the differentiation and prioritization of flows. The IoT brings together a varied group of applications of different types, belonging to different fields. Consequently, data from different applications do not have the same priority and different flows must be categorized based on their criticality and a certain prioritization must be applied through various appropriate QoS mechanisms. Based on the same concept of heterogeneity of applications, the QoS mechanisms applied must match the characteristics of these different applications. It is thus important to categorize IoT applications based on specific characteristics so as to offer the QoS mechanisms defined in the context of a homogeneous set of applications. Each set of applications will therefore have mechanisms that are well adapted to their requirements.

The performance management of the system, through the optimization of resource use to offer the best performance, is an important mechanism that we have to propose to ensure QoS at the level of this layer of the IoT architecture. The performance of the IoT environment must be monitored in order to meet the needs of clients using the IoT applications and to provide a service that fulfills the corresponding requirements. This monitoring consists of collecting precise information on the system and therefore the parameters for measuring the performance of the IoT environment must be well chosen. This choice makes it possible to specify parameters that are specific to the IoT, which must be quantified using the appropriate metrics.

Different protocols and communication technologies are used for information exchange between objects and gateways within the device layer in the IoT architecture. Therefore, the QoS mechanisms related to the device layer depend on these technologies. Some of these technologies have common bases, which makes it possible to generalize some of the QoS mechanisms used in this layer.