This document contains the results of the WP2 activities in the area of system architecture and related topics. The document builds on the results of the first year described in deliverable D2.2.1 “Initial e-SENSE System architecture” [1]. It consists of three distinct parts which expand the topics covered in D2.1.1 Section 6 “Gateway architecture”, D2.2.1 Section 7 “Reconfiguration aspects of the e-SENSE protocol stack”, and D2.2.1 Section 8 “Considerations for a Sensor Node Architecture in Year 2”.
Part 1 (Section 4) covers the “e-SENSE architectural enhancements” for the provision of novel context-aware B3G services and includes, in particular the required extension to incorporate a service provisioning platform within the architecture. The enhanced e-SENSE architecture starts from the gateway architecture defined in deliverable D2.2.1, which has been extended to cover the interface with the service delivery platform; the deliverable also identified and describes the functions required within the gateway in order to interface such platform. As just mentioned, e-SENSE is oriented to the provision of context-aware services within a B3G service landscape and, accordingly, IMS is the key service delivery platform analysed. The alternative approach of a web-service based platform has also been investigated, although to a lesser detail.
The architectural approach and extension proposed in this deliverable are based on a thorough review of the e-SENSE scenarios including an assessment of the suitability of IMS for the e-SENSE services and scenarios. Also, the advantages provided by embedded IMS features such as Instant Messaging, Multimedia Messaging, Presence etc for satisfying the identified requirements have been taken into consideration. The same identified requirements have also been considered for the web-service based architectural approach, and are reflected in the proposed mapping.
Part 1 of the document then focuses on the specification of an IMS e-SENSE Service Enabler that follows the IMS architecture and can thus extend it to allow context-aware services based on e-SENSE WSN to be seamlessly offered as part of an integrated IMS service offering. The e-SENSE gateway architecture has been enhanced by adding new functional elements such as the Service Promoter, responsible, in particular, for the service discovery service and the associated service and resource directory. Further, functional elements ? such as the Gateway Manager and the Middleware Interaction Manager - already identified as part of the architecture specified in deliverable D2.2.1, have been further detailed with the specification of their interface towards IMS (i.e., the e-SENSE service enabler within IMS). As mentioned above the main result presented is the e-SENSE Service Enabler itself. This enabler has been integrated within the IMS architecture, and its internal architecture has been specified together with the key interfaces and their applicable protocols and procedures.
Part 2 (Section 5) “System Reconfiguration”, provides insights into the three key areas of reconfiguration capabilities addressed by the project, namely: Protocol Adaptation, Protocol Stack Reselection and Dynamic Protocol Reconfiguration (Full Reconfiguration). The reconfiguration concept is based on the considerations made with regard to the application of wireless sensor networks identified by the work of WP1.
Ranging from personal application to industrial environments, from small networks of a dozen nodes to building size networks consisting of even a thousand nodes, a sensor network able to change its behaviour on demand will very valuable. This section of the deliverable describes how the e-SENSE system can provide solutions for those kinds of scenarios.
Part 3 (Section 6) “Sensor node HW architecture” addresses the internal architecture of a sensor node and the related procedures in order to facilitate management of the different energy scalable components of the sensor platform. The objective is design such architecture and define the procedure according to requirements and constraints coming from the environment as well as from the applications and to guarantee the required level of performance for the service, while saving energy and guaranteeing the lifetime of the WSN itself. It should be noted that reconfiguration and energy management/efficiency are related subjects as reconfiguration procedures may be triggered as a result of energy management policies.