A ready-to-assemble bed foundation including a pair of exterior beams connectable to a pair of transverse end members having openings, and an interior beam between the exterior beams having opposing end portions configured to engage the openings in the transverse end members. The crush-can is assembled within a frame rail or other chassis frame member. When a frame received from a path is transmitted to a destination terminal, a frame forwarding installation on the side of the destination terminal stores the identifier of this frame in a storage unit and, if a frame then newly arrives from a path, determines whether the frame identifier of this frame has been stored in the storage unit. The guide unit is provided at the other of the first casing and the second casing and configured to slidably guide a shaft. A processing circuit portion determines target data of the target based upon range and time measurements associated with reflected laser range-finding signals from the scans of the sub-field.