Middleware approaches for wireless sensor networks based on current trends

During the last years Wireless Sensor Network (WSN) technologies have been increasingly adopted and utilized as a prominent communication infrastructure in highly demanding application scenarios. However, in order to cope with the diverse and dynamic requirements of such cases in real deployment critical challenges must be addressed mainly stemming from the scarce resource availability characterizing state of the art WSN platforms. Aiming to tackle respective deficiencies and weaknesses a critical research domain has bloomed focusing on designing and implementing novel specialized middleware architectures. Indeed various approaches have emerged all targeting to harness all possible capabilities from WSN platforms in a flexible, efficient and dynamically reconfigurable way, not only at design time but most importantly in run-time. Driven by this new trends this paper attempts to offer a categorization of the most prominent one and analyze their main characteristics. Also a high level evaluation is presented with respect to their suitability in specific cases or/and requirements so as to assist designers to their effort to select the optimum one.