First of all, the system relies on the knowledge of real-time parking information, based on which it makes and
upgrades allocations for drivers. As already mentioned earlier, current sensing technologies provide several
options to monitor parking spots. In our pilot project, we use ultrasonic sensors, which are mounted in MEMSIC
IRIS wireless sensor motes. All sensors in one level of a garage or on one street construct an XMesh wireless
network, which connects all sensors together and transmits sensing data to the upper tier via a gateway. The
XMesh network supports multi-hop routing through which data packets can be relayed from one mote to another.
Thus, sensors far away can still transmit data to the gateway via this technology. It also has the capability of
quick reconfiguration when adding or removing a sensor to/from the system. These features make it very
convenient to deploy the parking surveillance system in either off-street or on-street parking spaces.
Moreover, whenever the system starts to make an allocation, it requires the location information of all cars
pending for allocation. Based on this information, it estimates the travelling time to the spot to be allocated, and
provides driving directions after the allocation. Current vehicle tracking devices/systems provide the solutions to
this problem. Vehicle tracking systems combine GPS tracking technology with flexible, advanced mapping and
reporting software. A vehicle tracking device is installed on a vehicle which collects and transmits tracking data
via a cellular or satellite network. The system receives real-time vehicle tracking updates, including location,
direction, speed, idle time, start/stop and more. This technology has been widely used in bus systems. However, it
requires each driver to install a tracking device, which becomes the additional cost for drivers to use the system.
In our project, we have built a smartphone application, which contains a function that constantly reads the GPS
data in the phone and automatically reports to the system. The smartphone application also has other functions,
which will be described later.