4.3.5 FMS/AVCM Subsystem Software Architecture
The FMS/AVCM subsystem provides three major architectural elements:
Components comprising the FMS are shown to the left of the vertical arm of the ORB in figure 4-9. It consists of an SNMP agent that indirectly controls attached ITS field devices by setting values in an SNMP device management information base (MIB). In turn, an FMS application responds to settings in the MIBís to direct the activities of device handlers or protocol translators. Data collected from the Whelen, Remote Traffic Microwave Sensor (RTMS), and Automatic Traffic Recorder (ATR) devices will be fused using a standard ITS incident detection algorithm to provide travel lane status and incident alarms. FMS applications communicate with device handlers and the CHART II database via the ORB.
The CHART II database will be implemented using a distributed model for two reasons. First, information is located closest to where it will normally be used. Second, a distributed database enhances system survivability. The commercial Database Management System (DBMS) engine will automatically retrieve requested information from wherever it is stored in the distributed system.
The AVCM is comprised of the AVCM application and SNMP manager to the right of the vertical arm of the ORB. Its purpose is to facilitate multicast distribution and prioritized control of ITS CCTV video for roadside cameras connected to the local ATM switch. The AVCM application receives and responds to requests from the operator GUI via the ORB. Based on information contained in the CHART II database, the AVCM directs the ATM network to create virtual connections between cameras and monitors by sending SNMP commands to the attached ATM switch SNMP agent.
Figure 4-9. CHART II FMS Application Architecture
CSC/PBFI Advantage: The FMS subsystem provides an intelligent distributed communication controller, a distributed database and an interface to an ATM switch