LOS may refer to any of the following:
1. Short for loss of signal, LOS is an indicator on a networking device that shows a signal or connection has been dropped or terminated. LOS can occur for many reasons such as, the cable connected to the network device is bad, there is no connection on the other end, improper network configuration, or the device itself is bad.
2. Line of Sight (LoS) means an object or character does not have an unobstructed view of another. Commonly used in computer gaming, not having LoS prevents a player from performing actions including healing or harming another player or NPC. For example, walls, hills, stairs, and trees are common objects that cause result in loss of Line of Sight. A games programming determines what objects can create Line of Sight issues.