RFID tracking using RFID tags do not require line of sight to be registered. Scanners or readers can either be fixed readers (attached to doorways) or hand-held for mobility. There are two types of RFID tags, passive (no battery) and active (battery-powered) that can transmit at larger distances. The type of fixed readers and tag to be considered will be dependent on the location point (height, width and surface to be mounted on) and cost (passive tags are cheaper than active tags). With RFID it is not a matter of one size fits all, the tags and readers that you use will depend upon the environment, asset types and the outcome you require.
More information on RFID asset tracking here