Evaluating the Use of DSMSs and CEP systems in Home Care Domain through a Comparison of TelegraphCQ and Cayuga

Abstract

Nowadays patients like to have the option of staying at home in their illness period. This can be realized through observing and monitoring the patients motion and temperature with an home care application. Sensors are placed in the home and create a real-time stream which have to be analyzed. Data Stream Management Systems (DSMSs) and Complex Event Processing systems (CEP) support real-time analysis of data streams which is a continuous ordered sequence of tuples. There are some differences in the design and implementation of these systems. We analyze these differences and similarities for two such systems; TelegraphCQ, a DSMS and Cayuga, a CEP system, with a focus on how well they might suit the needs of home care application domain. Some of the most important criteria for a system in a home care environment are to have a system with a language that allows an application to formulate appropriate queries. In consideration of this we conclude that compared to Cayuga, TelegraphCQ is the most capable system for home care domain. The reason for this is that the query language of Cayuga has too limited expressiblity. And its operators are too difficult to use for expressing the queries that are typical in this application domain. TelegraphCQ in contrast does report the correct value and time interval with the possibility to use built in functions from SQL and do not demand query with lot of complexity. The comparison is done in two parts; theoretical and practical. We focus on topics like tuple definition, aggregation, consecutiveness, concurrency and optimization. Through the first part we investigate the literature concerning the two types of systems. The second part consist of testing these systems in the home care application domain. This part allows us to test the topics discussed in the theoretical part.