162 PART | IV ITS regulations, policies and standards
and processes. The key component of SWE is Sensor Model Language
(SensorML). The OGC has worked with IEEE and the Marine Plug-and-
Work Consortium to harmonize SWE standards with the IEEE 1451 stan-
dard and with the PUCK standard, respectively at the web application level.
This provides sensors with the ability to expose web interfaces and thus
being easily interconnected in an ITS.• The Cooperative ITS (C-ITS) is a protocol stack defined for the ve-
hicle to infrastructure communication part of ITS (Uhlemann, 2015;
Festag, 2014). In the access layer, it defines ITS-G5 for Europe and Wire-
less Access in Vehicular Environment (WAVE) for US, both as special-
izations of the IEEE 802.11-2012 standard. The networking layer employs
GeoNetworking whereas the Basic Transport Protocol (BTP) is used in
the transport layer. However, internet protocols such as IPv6 coined with
TCP, SCTP or UDP are also supported in the transport layer. At the top
layers of applications and facilities, protocols as CAM or DENM are used
for communicating vehicle state information, traffic or road condition in-
formation in the area, and supporting the development of safety and traffic
efficiency applications. Applications standards of C-ITS define minimum
requirements for road-hazard signaling (RHS) applications, or collision-
risk warning (CRW) applications in intersections (ICRW) or everywhere
(longitudinal CRW). Finally, security- and privacy-related standards build
on ETSI standards for PKI enrollment (ETSI TS 102 940), data integrity
(ETSI TS 102 942), authorization (ETSI TS 102 097), and confidentiality
(ETSI TS 102 941) and define different trust assurance levels (TAL). The
set is complete by standards for decentralized congestion control and test
standards for verification of conformance to base standards and to indus-
trial specifications.
• As far as it concerns smart transportation, several countries have issued stan-
dards that cover short-range communications, electronic tolls, traffic infor-
mation services, etc. (Ge et al., 2017). The 3rd Generation Partnership Proj-
ect (3GPP) is a standards organization which develops protocols for mobile
telephony (https://www.3gpp.org). V2X (vehicle to everything) specifica-
tions use the LTE (Long-term evolution) as their underlying communication
technology. Based on the 4G TD-LTE (Time-division long-term evolution),
the LTE V2X (Long-term evolution vehicular to X) standard emerges as
a competitor to 802.11p and provided support for both direct communica-
tion (V2V, V2I) and wide-area communication over a 5G cellular network
(V2N).
• CEN/TC 278 working groups are actively engaged with smart transporta-
tion applications and provide links to standards and standardization activi-
ties among others for—(1) electronic fee collection, (2) public transport, (3)
traffic and traveler information, (4) geographical data, (5) traffic informa-
tion, (6) user interfacing, (7) eSafety (eCall), (8) cooperative ITS, and (9)
mobility integration and urban-ITS.