The WilliamsRDM START™ Sensor Network for border security is a low power wireless mesh network intrusion detection system consisting of sensor nodes, cluster nodes, and a server application.  The system is deployed in a rough grid pattern 1/4 to 1/2 mile deep along the border, with nodes spaced approximately 100 meters apart.  One mile of border would require 150 to 200 sensor nodes and 2 cluster nodes.

The sensor and cluster nodes incorporate a suite of sensors to detect border intrusions by people or vehicles as well as integrated GPS to precisely locate intrusions.   The sensor nodes form a wireless mesh network to communicate to one another and to the cluster node.  The cluster node sends data to the server application through satellite or other long range RF links.  The server application is responsible for further analyzing and then presenting node and intrusion location information via a web based map enabled Graphical User Interface (GUI) to border patrol personnel.

The difference between sensor and cluster nodes is that cluster nodes have additional processing capability to communicate and analyze data from up to 200 sensor nodes; as well they have higher power radio transmitters for longer range satellite/RF communications to the server application and/or directly to border patrol personnel.  Sensor nodes detect intrusions by changes in Radio Frequency signal strength between nodes, augmented by other sensors on each node, and a multi-tiered filtering algorithm to eliminate false detections.   As the server application GUI is web based, any device that has a browser and has access to the internet can securely view information.

The unique advantage of the START™ Sensor Network system is its ease of deployment, low cost (90% less than a physical wall), and its inherent reliability due to its use of a wireless mesh network.  Nodes do not have to be manually placed when deployed.  Each node is rugged enough to be deployed by ground or air.  The system is designed to use very little power, requiring only batteries and small solar panels.  All electronics and batteries are potted within a sealed enclosure with no openings and there are no moving parts, thus no maintenance of the deployed nodes is required.  With no maintenance and using solar power, each node has a multi-year deployment life.  The system uses a very simple Radio Frequency “trip-wire” capability, augmented with other sensors, to detected intrusions and uses a multi-tiered configurable filtering system to eliminate false detections.  Each node self-activates upon deployment; each node turns themselves on upon impact and begins communicating automatically with the rest of the network, to the back-haul communications link, and to the application server.  As the system is deployed in a rough grid pattern 1/4 to 1/2 mile deep along the border and consists of a wireless mesh network, there is sufficient sensor density to provide multiple communication paths for RF “trip wire” detection, thus if one or more sensor nodes is damaged or destroyed, there will be no gap in the networks ability to detect intruders.  The system may be deployed along the entire length of the border, or it can be deployed to augment physical walls and/or be deployed in areas where it would be difficult or cost prohibitive to build a physical wall.  As it is made up of a wireless mesh network which transfers sensor data to monitoring servers, it can serve a dual use function of monitoring weather, the environment, air quality, or anything that one could monitor with sensors deployed to communicate through the network.