A location tracking system is provided for tracking the location of a child or other individual. The location tracking system includes a location server and one or more location tracking devices. Communication protocols are provided for communications between the location server and the location tracking devices. The communication protocols provide a low complexity and low cost solution for location tracking applications.

A non-lethal electronic defense device comprising one or more effects such as light, sonic, ultrasonic, infrasonic, chemical, electrical, or mechanical devices capable of causing intense sensations of disorientation, distress, incapacitation, and/or pain for the purpose of protecting a public or private space from an intruder or attacker exhibiting an intent to cause harm to physical inhabitants or destruction of property therein.