1. A method for monitoring a border at a monitoring facility, comprising: arranging sensors along the border, the sensors each having a communications device to enable each sensor to communicate with the monitoring facility including receiving commands from the monitoring facility and providing data to the monitoring facility; providing each of the sensors with a wake-up component that detects a condition around the sensor that requires monitoring, the wake-up component causing, upon detection of the condition around the sensor requiring monitoring, each sensor to wake-up from an inactive phase to enable the sensor to obtain data; obtaining data about the border via at least one of the sensors that has been woken-up by the wake-up component thereof; analyzing the obtained data using a processor unit at the at least one sensor to determine the presence of a reportable condition relating to passage of an object proximate or over the border; and transmitting the obtained data or a signal indicative of the analysis from the at least one sensor to the monitoring facility using the communications device of the at least one sensor, whereby data or the signal is transmitted by the communications device of the at least one sensor to the monitoring facility and received by the monitoring facility only when the processor unit of the at least one sensor determines the presence of a reportable condition from the data obtained by the sensor.