New Virtual Remote Laboratory Environments for Logic Circuit Design Realizing an efficient sharing of Test Equipments and Concurrent User Support

The distance learning is widely spreading its use in many areas thanks to the Internet advancement. One of the emerging areas is the remote laboratory. The proposed remote laboratory system is to realize an internet based remote digital logic circuit experiment, which enables efficient sharing of test equipments both in space and time division fashions as well as supporting many users to perform experiments concurrently. Most existing remote laboratories are based on exclusive use of experimental equipments applying the client-server models via the Internet. Once users start remote experiments, these test-benches including target FPGA boards, logic analyzers or pattern generators are exclusively occupied for a long period of time._As available test-bench numbers are strictly restricted to the available physical numbers, it becomes difficult to provide enough experimental environments supportable for many users at the same time. In order to overcome such shortcomings, the authors realized virtual experiment environments, which share actual experiment equipments in space and time division fashions on demand basis. Each user is allocated a virtual experiment environment. It is possible to reside many virtual experiment environments in the system more than the available_test-benches. In the course of the test-and-experiments, available physical equipments necessary to the experiment are dynamically allocated to the virtual environments. In order to resolve the conflicts among equipment usages, the job submission and allocation system, Condor has been employed as the job manager. Although Condor was originally developed for parallel machines to allocate jobs, it is also suitable for the virtual experiment environment handlings. It submits many virtual experiment environments at the same time and allocates equipments according to experiment-runs. As each experiment-run contains number of different experiment stages, where usages of the equipments differ from each other, a- - n efficient sharing of equipments becomes possible.