The IETF standards for IoT embrace a web service architec-
ture for IoT services, which has been widely documented in the
literature as a very promising and flexible approach. In fact, web
services permit to realize a flexible and interoperable system that
can be extended to IoT nodes, through the adoption of the web-
based paradigm known as Representational State Transfer
(ReST) [18]. IoT services designed in accordance with the ReST
paradigm exhibit very strong similarity with traditional web
services, thus greatly facilitating the adoption and use of IoT
by both end users and service developers, which will be able to
easily reuse much of the knowledge gained from traditional web
technologies in the development of services for networks con-
taining smart objects. The web service approach is also promoted
by international standardization bodies such as IETF, ETSI, and
W3C, among others, as well as European research projects on the
IoT such as SENSEI,5 IoT-A,6 and SmartSantander.1