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9.3 Related Works 335
Specifically, it has been defined a lightweight version of the Domain Name
Systems (DNS) extensions for local discovery based on multicast, the called
mDNS, and the DNS Service Discovery semantic to describe services and
resources over DNS.
The black components are the other ones key buildings blocks from the
digcovery architecture. The first key component is the semantic description;
it is a very important issue in order to provide a powerful IoT6 Open Service
Layer. For this purpose are several the actions carried out in order EU projects
such as SPITFIRE, from the European Commission with the support of events
such as the Interoperability PlugFest in conjunction with Probe-IT project, and
standardization groups such as IPSO Alliance, ETSI and the recent released
one M2M.
The second key component is the Search Engine; this is the key element of
any discovery solution in order to make it powerful. Digcovery has integrated
MongoDB with some extensions based on geo-location, application profiles
and domains, in order to make it feasible the context awareness look-up.
The third key component is the management functions and communication
interfaces in order to interoperate with third party platforms and solutions. It
has been considered CoAP to be compatible with the current Internet of Things
trends, SenML and JSON to be compliance with the IPSO Alliance and IETF
approaches, and other enterprise interfaces such as RLUS for management.
Finally, it has been defined a port with the third party platform used in OpenIoT
in order to extend and integrate the designed solution with the OpenIoT solution.
The Figure 9.9 presents the communications interfaces with the different
protocols.
9.3 Related Works
Currently, there are several projects that, in a way or another, make use of
semantic middleware architectures, or at least that are partially inspired by
them.
WoO (Web of Objects) is an ITEA2 project that, to begin with, has as
its main objective creating an infrastructure for smart objects where networks
and services will be deployed with independence of any proprietary protocols
that may be present in the system [23, 24]. From the very beginning, WoO has
been conceived to use a semantic approach in modelling devices and services,