of the system. The collection of all terminate the application, respectively. files describes, "the identity, capabilities, properties, inter-dependencies, and location of the hardware devices System control and software components that make up the system" [11] In order for the radio system to behave as a single system, and is referred to as the Domain Profile. The Domain a unifying point is necessary. The specific nature of the Profile is in XML, a language similar to the HyperText unifying point can be as simple as a central registry, or as Markup Language (HTML), which is used to associate sophisticated as an intelligent controller. In the SCA, this values and other related information to tags. XML is unifying point is neither. The DomainManager, which is relatively easy for a human to follow and, at the same the focal point for the radio, is such an entity, and its time, easy for a machine to process. task is as a central registry of applications, hardware, The relationships among the different profiles is shown and capabilities. Beyond this registry operation, the in Figure 2.4a-12. As seen in this figure, there are seven file DomainManager also serves as a mount point for all types: Device Configuration Descriptor (DCD), Domain- the different pieces of the hardware's system file. The Manager Configuration Descriptor (DMD), Software As- DomainManager also maintains the central update sembly Descriptor (SAD), Software Package Descriptor channels, keeping track of changes in status for hardware (SPD), Device Package Descriptor (DPD), Software and software and also informing the different system Component Descriptor (SCD), and Properties Descriptor components of changes in system status. (PRF). In addition, there is Profile Descriptor, a file The point at which the DomainManager is created containing a reference to a DCD, DMD, SAD, or SPD. can be considered to be the system boot-up. Figure 2.4a- The profiles have a hierarchical structure that is split 10 shows this sequence. As seen in Figure 2.4a-10, the into 