LMU
Location Measurement Unit
A typical cell site will feature an LMU in order to support network based location services. The LMU is responsible for taking specific radio interface measurements, typically under the control of the SMLC (Serving Mobile Location Centre). Measurements are often in relation to TDOA (Time Difference On Arrival) which, when combined with the measurements taken from three or more other LMUs can be used to triangulate the location of the subscriber.