For deep bores, the most common tracking method uses a “wireline” to connect a tracking mechanism behind the drill head to the surface. This wireline connection presents difficulties because the connection must be maintained as new sections of drill rod are added. 

As an alternative to the wireline connection, signals from the tracking mechanism at the drill head can be wirelessly transmitted through the ground to the surface using a mud pulse data transmission system or a "through the ground" wireless telemetry system. The mud pulse system has low data transmission rates and the wireless ground telemetry system may encounter communication difficulties depending on the depth, distance separation between transmitter and receiver and/or adverse ground conditions.