Resumen: The Internet of Things (IoT) concept proposes that everyday objects are globally accessible from the Internet and integrate into new services having a remarkable impact on our society. Opposite to Internet world, things usually belong to resource-challenged environmentswhere energy, data throughput, and computing resources are scarce. Building upon existing standards in the field such as IEEE1451 and ZigBee and rooted in context semantics, this paper proposes CTP (Communication Things Protocol) as a protocol specification to allow interoperability among things with different communication standards as well as simplicity and functionality to build IoT systems. Also, this paper proposes the use of the IoT gateway as a fundamental component in IoT architectures to provide seamless connectivity and interoperability among things and connect two different worlds to build the IoT: the Things world and the Internet world. Both CTP and IoT gateway constitute a middleware content-centric architecture presented as the mechanism to achieve a balance between the intrinsic limitations of things in the physical world and what is required fromthem in the virtual world. Said middleware content-centric architecture is implemented within the frame of two European projects targeting smart environments and proving said CTP’s objectives in real scenarios. Idioma: Inglés DOI: 10.1155/2014/158252 Año: 2014 Publicado en: International Journal of Distributed Sensor Networks 2014 (2014), 158252 [18 pp] ISSN: 1550-1329 Factor impacto JCR: 0.665 (2014) Categ. JCR: TELECOMMUNICATIONS rank: 58 / 77 = 0.753 (2014) - Q4 - T3 Categ. JCR: COMPUTER SCIENCE, INFORMATION SYSTEMS rank: 106 / 139 = 0.763 (2014) - Q4 - T3 Tipo y forma: Artículo (Versión definitiva) Área (Departamento): Área Ingen.Sistemas y Automát. (Dpto. Informát.Ingenie.Sistms.) Área (Departamento): Área Tecnología Electrónica (Dpto. Ingeniería Electrón.Com.)