In accordance with one embodiment of the invention, a broadcast server system computes a feasible stretch value for use in scheduling job requests. An encrypted content file distributed by a contents distributing site via a network is received, and copyright protection information indicative of whether or not the received encrypted content file requires copyright protection is acquired. After detecting that it has received a full set of routes from each neighbor, the router performs route selection procedures to select the preferred routes and advertises these routes to its neighbors. The wafer carriers may be configured to move to and from the load-and-unload cup in a pivoting manner. At least a portion of the stopper is flexible between a first position and a second position.