Testing Agile Information Management Systems with Video Test Client. Case Study - DIMES

摘要

In a Network Centric Warfare (NCW) environment, geographically distributed forces are networked together to attain military advantage, e.g. force agility. At the core of NCW is the ability for these distributed forces to collaborate and share information, which are the two services provided by information management systems located on the Global Information Grid (GIG). Due to the fact that a single system can not be perfect for all possible applications, system architects must sort through the different choices and select the best one for the desired application. In order to do so, designers must be able to understand what the capabilities of the system are in a common language. Quality of Service (QoS) metrics provide one means of describing these capabilities. Like netcentric forces, it is desired that the supporting information management system also be agile. The notion of an agile information management system (AIMS) is introduced and the associated QoS attributes are defined. Video Test Client (VTC) is a QoS test platform that uses audio and video data as the basic unit of information. It is capable of using both pre- recorded and live video, i.e. video telecasting and teleconferencing, steams for testing. Its design and capabilities are also discussed. VTC was used to obtain latency and jitter measurements for the Distributed Information Management Enterprise Service (DIMES), an AIMS under development at the Air Force Research Laboratory, Information Directorate. Preliminary results shows that DIMES introduces 787 microseconds of latency, on average, resulting in a maximum of 190 good quality simultaneous collaboration streams with 20fps audio and 30fps video.