This paper addresses the Internet of Things. Main enabling factor of this promising paradigm
is the integration of several technologies and communications solutions. Identification
and tracking technologies, wired and wireless sensor and actuator networks,
enhanced communication protocols (shared with the Next Generation Internet), and distributed
intelligence for smart objects are just the most relevant. As one can easily imagine,
any serious contribution to the advance of the Internet of Things must necessarily be the
result of synergetic activities conducted in different fields of knowledge, such as telecommunications,
informatics, electronics and social science. In such a complex scenario, this
survey is directed to those who want to approach this complex discipline and contribute
to its development. Different visions of this Internet of Things paradigm are reported
and enabling technologies reviewed. What emerges is that still major issues shall be faced
by the research community. The most relevant among them are addressed in details.