Vehicular Sensor Networks: General Aspects and Implementation Issues - Application and Multidisciplinary Aspects of Wireless Sensor Networks - page 214

10.5.1 Node Configuration

The architecture of a vehicle sensor system is determined by the specific environ-
mental conditions and requirements it operates in. Determining factors comprise
high range of ambient temperature variations, excessive dust and moisture content,
high level of shock and vibrations, specific battery power supply, mobility, etc.
Taking into consideration the rapid development of different vehicle specific sen-
sors as well as the increasing demand for fast collection, processing, storage, and
transmission of measured data, VSNs require the use of embedded computing plat-
form rather than constrained micro controller. As shown in Fig. 10.5 [ 29 ], a vehicle
sensor device contains a processor, a memory, a radio transceiver and antenna, a
power source and an input/output interface that allows the integration of external
sensors into the wireless device.
The central processing unit is a box computer, fan less and diskless design, small
form factor, incorporating some of the Intel's “M” or “Atom” high speed and low
power processors, powered by Windows Embedded or Windows CE platform.
Providing a multitasking operating system, different node operations can be per-
formed as separate threads or processes. For example, while one thread is employed
in collecting and transforming the sensor data, the other can be dedicated to com-
munication with other nodes in the network. Its robust design and low power require-
ments make this type of computers ideal for VSNs. Specially designed Vehicle
Software Package (VSP) is in charge of reading raw sensed data, processing them,
and generating summaries. Summaries include context metadata (location, timestamp
etc.) and features extracted by local filters. For instance, VSP includes a filter that can
determine position of the vehicle, vicinity to other objects, etc. Moreover, VSP com-
mands the storage of both raw data and summaries in two local databases. Summary

Fig. 10.5 VSN node (device architecture)