Assessing Remote Data Access feasibility for the ITER Remote Experimentation Centre

Remote data access is a mandatory requirement for large devices operated by international teams. Data acquired during experimental sessions should be soon available at remote sites for on-line analysis and visualization. Network throughput plays an important role, but overall performance depends also on the strategies adopted by the data system in order to optimize data transfer, increasing throughput and reducing latency. The ITER Remote Experimentation Centre (REC) in Rokkasho [1] is one of the projects currently implemented within the Broader Approach agreement [2]. The ultimate objective of the REC is to allow researchers to take part in the experimentation on ITER from a remote location. The technologies developed for the REC include Remote Data Access (RDA) tools [3], which allow the users to access to the experimental data, regardless their geographical location. MDSplus is the most widespread data system that is used in the fusion community for remote data access and is the candidate technology for exporting ITER data at the REC. The paper reports the measured performance in remote data access between Europe and Japan using MDSplus and describes several strategies that have been adopted in order to optimize data transfer. In particular, solutions for data streaming requirements and remote access of very large signals, as they represent important requirements in large experiments.