3. System overview and implementations
NeverStop has been designed to integrate into an intelligent
traffic lights management system ensuring that there is minimal
need for additional hardware, as is illustrated in Fig. 1. The system
is comprised of the following components:
EBOX II: the hardware package housing the NeverStop System
Controller and providing connectivity to the traffic lights, the RFID
device and the Central Server. This unit runs a customizedWindows
CE OS image.
Light Control Unit: the controller to interface with the traffic
lights and EBOX II. It may be consisted of one or several PCB(s).
RFID device: the device to send the car flow information to the
EBOX II. It normally contains the following components: tags, readers,
and antennas. We deploy the device both at the entrance and
the exit of the lane.
Central server: the server is in charge of making all the terminal
EBox work in parallel and provides references and historical
data. The central server primarily provides a means of guaranteeing
resilience in the accidental event of an unexpected catastrophic
failure of NeverStop.
Obtained with the above components, the system must adhere
to the following performance requirements:
(1) Frequency of RFID device
The RF tag works on a certain frequency. Taking our system
model into account, we choose ultra high frequency (UHF)
or microwave tag for mobile object identification. Usually, as
microwave RF tag, the effective distance for recognizing information
can reach 3–5 m.