Wireless communication system for underground pipeline inspection. The system includes a plurality of sensor nodes moved by robots within the pipeline and each sensor node includes a radio transceiver. A plurality of spaced apart, above ground relay nodes are deployed along the pipeline, each relay node including a radio transceiver for communication with the sensor nodes. A remote monitoring center is provided in communication with the relay nodes, whereby a leak detected by a sensor node is communicated to the remote monitoring center. Each sensor node may further include a microcontroller, an accelerometer and a timer.