The term "LITEM" is an acronym that stands for "Line-of-Sight Transmission Error Metric." It refers to a measure used in wireless communication systems, particularly those using radio frequency signals. LITEM measures how well data can be transmitted between two points without any physical obstructions or interference getting in the way of the signal's path. The lower the value of LITEM, the better the line-of-sight transmission quality is for a given system.