Wireless sensor networks have found multiple applications in precision viticulture. Despite the steady progress in sensing devices and wireless technologies, some of the crucial items needed to improve the usability and scalability of the networks, such as gateway infrastructures and in-field processing, have been comparatively neglected. This paper describes the hardware, communication capabilities and software architecture of an intelligent autonomous gateway, designed to provide the necessary middleware between locally deployed sensor networks and a remote location within the whole-farm concept. This solar-powered infrastructure, denoted by iPAGAT (Intelligent Precision Agriculture Gateway), runs an aggregation engine that fills a local database with environmental data gathered by a locally deployed ZigBee wireless sensor network. Aggregated data are then retrieved by external queries over the built-in data integration system. In addition, embedded communication capabilities, including Bluetooth, IEEE 802.11 and GPRS, allow local and remote users to access both gateway and remote data, as well as the Internet, and run site-specific management tools using authenticated smartphones. Field experiments provide convincing evidence that iPAGAT represents an important step forward in the development of distributed service-oriented information systems for precision viticulture applications.
