University of Connecticut ECE 290 Spring, 2004
Sponsor: ECE Department, University of Connecticut Advisor: Lei Wang David Crouse (EE)
Michael Diaz (EE)
Darko Budimir (EE)
Our group investigated wireless security system
design for home use. The target market is composed of lowincome individuals who cannot afford the services of a security company such as ADT. Ideally the sensor nodes
would communicate their status to a base station through mesh networking, however, after experiencing a few difficulties,
only an IR barrier sensor, and a motion detector, powered by PIC microprocessors were completed along with a sample
program for UART communication. Hardware was designed
and built to demonstrate a star network of sensors
communicating to a base station, via aRadiotronix WiSE
network, however communication difficulties with the
Radiotronix boards occurred and the boards were unable to
The main predecessor to the current Wireless
Network Sensor (WSN) system is a technology called Packet
Radio. It was first introduced in the 1960s, in two main
research organizations: The Rand Corporation, the original
non-profit think tank helping to improve policy and decision making through objective research and analysis; and the
Defense Advanced Research Projects Agency (DARPA), a
military agency devoted to national security through weapons development.
These two corporations set out to develop a system
that would interconnect a research computer network, spread
across the islands of Hawaii. In this system, the sensor nodes were computer terminals, arranged in a Star Topology (refer to 1
Figure 1) , that computed data and transmitted results to a
central base station.
Be it a priceless heirloom or silverware acquired in
better times, many low-income individuals own valuable
property. Sadly, the poorest communities are often the ones
with the highest crime rates. Though residents of such areas might benefit from home security services, such as ADT, most are not able to afford the high costs of installing and
maintaining such services. Also, many such services require
wires to be installed within the walls of the house. Many
people, especially the poor, rent their homes. In such an
instance, the tenant might be unwilling to invest in a security system if they cannot take it with themselves when moving
and the lease might forbid such alterations. The ideal home
security system for the poor would not require professional
installation nor would it be expensive to purchase or maintain. Our work looked into a solution to these issues in the form of a WIRELESS SENSOR NETWORK (WSN).
The Wireless Sensor Network (WSN) system in development
today, has a main predecessor and several related wireless
network models: specifically Packet Radio technology,
cellular networks, and Bluetooth. All these related models
have either physical or implementation constraints that differ to our proposed system, but we mainly wanted to focus on the fact that none of them deal with a multi-hop topology. None
of these models require their sensor nodes to depend on
another sensor node to communicate with the central base
Figure 1. All nodes in a star network communicate directly with the base.
As one would expect, the system was not without
faults, specifically collisions were occurring between their 1
The terminals in Packet Radio were arranged in a Star Topology, where the terminals are all distributed around one main and central base station. In a wired system, synchronizing all the terminals with the base is not a difficult task, and thus controlling the order of transmission does not allow for collisions.
computer terminals. In packet radio, these collision happened when a terminal attempted to contact the base station at the same...