System Architecture Design

pSHIELDSystem Architecture DesignPUWe can define the architecture of a pSHIELD Subsystem (pS-S) as a set of Embedded System Devicesincluding several L-ESD, connected to several pS-ESD and one and only one pS-SPD-ESD. Connectionsbetween two generic ESDs (L-ESD, pS-ESD or pS-SPD-ESD) can be performed, by means of legacyfunctionalities at Node, Network and/or Middleware layer, through the so-called NC, NS and MSfunctionalities, respectively. This means, for example, that the legacy Node layer capabilities (e.g. legacyphysical connectors) of an L-ESD can be used to connect it to a pS-SPD-ESD having a compatible Nodelayer capability (e.g. the same connector format factor). The connection of a pS-ESD with another pS-ESD or with a pS-SPD-ESD can also be performed by exploiting the additional pSHIELD Middlewarelayer functionalities exposed by the pS-MS interface. Each pSHIELD Subsystem (pS-S) must have oneand only one pS-SPD-ESD, so that a pS-SPD-ESD can be connected to another pS-SPD-ESD by meansof so called pS-OS functionalities. A pSHIELD Subsystem is depicted in the following figure.Figure 40 – pSHIELD Subsystem architecture decomposed into ESD componentsLet’s consider a pSHIELD system including several Embedded System Devices belonging to the threeabove defined types of ESD: L-ESD, pS-ESD and pS-SPD-ESD. The pSHIELD system architecture canbe represented as a set of pSHIELD subsystems each connected to the other by means of the overlayinterfaces provided by the Service Agent:Figure 41 – pSHIELD System Architecture decomposed into pSHIELD SubsystemPUD2.3.2Issue 5 Page 110 of 122