Overview RequestReply Interaction Model

SANY D2.3.4 Specification of the Sensor Service Architecture V3 Doc.V3.1 Copyright © 2007-2009 SANY Consortium Page 60 of 233

6.3. Models of Interaction

6.3.1 Overview

The SensorSA uses the taxonomy proposed in MuehlFiegePietzuch, 2006 in order to characterise the interaction models between the service components in a sensor service network. The taxonomy is based upon the way interdependencies between the service components are established see Figure 6-3. Figure 6-3: Taxonomy of Interaction Models MuehlFiegePietzuch, 2006 It is expressed by two attributes: the initiator attribute, which describes whether the consumer or the provider initiates an interaction, and the addressee attributes, which describes whether the addressee of the interaction is known i.e. directly addressed or unknown i.e. indirectly addressed.The SensorSA currently supports the following interaction models: - requestreply interaction model see section 6.3.2 - event-based interaction model see section 6.3.3 Note: These are interaction models between the logical service components without making assumptions about the underlying infrastructural means e.g. communication protocols to implement these interaction models. Furthermore, both interaction models may be applied to implement the two logical interface types that are distinguished in the service viewpoint of the sensor model see section 5.5: the information and the management interface.

6.3.2 RequestReply Interaction Model

In the requestreply interaction model the initiator is the consumer also called client that requests data or functionality from the provider also called server. The initiator either expects data to be returned or it relies on a specific task to be done. The consumer knows the provider in the sense that it may directly address the provider. The address may have been acquired through pre-knowledge configuration or by means of resource discovery see section 10.2. The requestreply interaction model is applied in most of the services and interfaces specified in the Service Viewpoint in section 7. Note: In cases where the addresses of the providers are not known, MuehlFiegePietzuch, 2006 talk about the anonymous requestreply interaction model. This SANY D2.3.4 Specification of the Sensor Service Architecture V3 Doc.V3.1 Copyright © 2007-2009 SANY Consortium Page 61 of 233 interaction model may be applied in the sensor domain of the SensorSA functional domains see Figure 6-1 and implemented by broadcast or multicast communication protocols in sensor networks. However, these communication protocols are conceptually out of the scope of the SensorSA., because, as explained in section 2.1, the SensorSA specification is independent of the specifics of a particular service platform.

6.3.3 Event-based Interaction Model