ITS standardization bodies and standards Chapter | 14 161process, the correction data, as well as information related to the transduc-
er’s manufacturer. With this model sensor manufacturers are allowed to sup-
port multiple protocols and networks, given that the provide the necessary
information for them, thus adding to the interoperability of the transducer
across different networks and making transducers network independent.• The OGC’s PUCK Protocol Standard (O’Reilly & Reed, 2014) is used
by instruments that interconnect through Ethernet or RS232 and defines a
standard protocol for storing and retrieving data and metadata from the in-
struments. It is mainly used for marine applications and has already been
implemented in the firmware of many instruments.
Communication technologies are another key component, which handles the
connectivity between the ITS core and its sensing and actuating components
(Ali, 2014). All the data collected by the sensors of an ITS must be communi-
cated to the processing nodes and all the output decisions and actions of this
process must be communicated to the actuators and actors (end-users) of the
system in order to support an informed decision making. Depending on the
application goal, which can be either monitoring, control or safety, and differ-
ent sensor network standards are more appropriate. Wireless sensor network
standards comprise among others:
• The ZigBee standard (https://zigbee.org/) was mainly developed for provid-
ing low-cost wireless connectivity in short distance and gives priority on
low-power consumption over data rate and response-time delay. It supports
various network topologies, with tree topology being the best choice for
large-scale applications. It has been employed for monitoring applications
in ITS (Heredia et al., 2019).
• The WirelessHART is an alternative of ZigBee (Jindal & Verma, 2015),
which extended the Highway Addressable Remote Transducer (HART)
protocol in factory automation. WirelessHART supports bi-directional field
communication, but avoids unnecessary communication costs and ensures
long-battery life. This is achieved by implementing on-demand communica-
tion. It uses a flat mesh-network topology, where all field devices that form
the network serve simultaneously as a signal source and a repeater. In the
physical layer, it employs the IEEE 802.15.4- 2006 standard and defines all
other communication layers.
• Other standards which are quite popular for industrial automation systems,
such as ISA100.11a and WIA-PA are not very frequently used in ITS.
Cooperation of system components (vehicles, infrastructure, etc.) is very
important for the development of ITS and thus several standards (Festag, 2014)
have been defined in this direction:
• The OGC (Open Geospatial Consortium) defines a series of open stan-
dards, known as the Sensor Web Enablement (SWE), which comprises of
data models and XML encoding that allow describing sensors, actuators,