An important part of the assessment of asset condition is to determine the current structural adequacy of the utility, to try to predict its remaining service life and, if necessary, to determine suitable methods for its rehabilitation or replacement. These methods examine the wall condition (pipe material condition, pipe wall integrity and, where corrosion or erosion are present, the remaining pipe wall thickness). Taken together with the visual/laser interpretation of pipe cross-section geometry and any information that can be gathered about hidden external voids adjacent to the pipe, structural adequacy assessments can be made. Some sensors systems also are directed at directly interpreting structural responses to imposed loadings or monitoring a pipeline for evidence of deterioration (e.g. acoustic sensors for prestressed concrete pipelines which listen for wire breaks). This is an active field of research with many different types of sensor systems and methods of deployment. Providing for the long-term power requirements for sensors and the means for periodically collecting data via wireless connections are key application issues. However, the goal of creating inexpensive autonomous monitoring systems that can be economically and widely distributed across large underground pipe networks is an important goal for long-term asset management.