Information Technology Reference
In-Depth Information
The ID is communicated back to the reader by varying the load on the antenna's coil,
which changes the current drawn on the reader's communication coil. RFID systems
based on UHF and higher frequencies use far-field communication and the physical
property of backscattering or “reflected” power. Far-field communication is based on
electric radio waves. Actually, the reader sends a continuous base signal frequency that
is reflected back by the tag's antenna. During the process, the tag encodes and modu-
lates the signal to be reflected with the information from the tag (the ID).
The evolution of VSNs requires various systems, from embedded to fully
Internet capable ones, to interoperate, adapt to various environmental conditions,
and deliver a user-transparent and seamless vehicular environment communication.
It inevitably leads to adoption of novel technologies and communication concepts
that facilitate automatic information collection and dissemination under dynamic
conditions. The RFID technology has the potentials to deliver these necessary pre-
requisites for future generation VSNs. Its characteristics allow it to be easily inte-
grated into a vehicular environment. Nowadays examples comprise fleet management
systems [
36
], the RUNES project defined integrated heterogeneous embedded sys-
tems [
37
] etc. However, the development of the RFID technology must be viewed
with caution and jointly with VSNs to allow the evolution. Otherwise, it may
devolve into proprietary-based single-use applications that limit its potentials.
10.7
VSNs Applications
After scrutinizing the most important aspects of VSNs, this section will focus on
classification and analysis of the most prominent VSNs applications in use today.
The applications are the driving force of vibrant research in all technology fields
and the VSNs are no exception to this rule.
VSNs' applications can be broadly divided into:
•
Safety applications
(potential killer applications)
•
Non-safety applications
Safety applications are used for traffic accident prevention and life's salvation,
whereas the non-safety applications are a step forward toward ambient intelligence
in a vehicular environment. The data used for VSN applications is gathered mostly
by sensors capable of detecting distance, position, and speed. This subsection will
pinpoint some of the most prominent and interesting VSN applications today con-
veying the previously mentioned classification.
10.7.1
Safety Applications
The VSNs safety applications' target is the “safety margin”, i.e., the time in which
a potential accident is detected before it may actually occur. The objective is there-
fore to inform the drivers about a potential risk sufficiently in advance to avoid
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