A time slot boundary of an unknown cell in a telecommunications system is identified by correlating a received signal with a known code over a range of delay values for each of one or more time slots, wherein the known code is used by all cells in the telecommunications system. The switching device has a data receiving unit, an assigned data transport unit, an unassigned data transport unit, and a lower transport layer transport unit. The in-plane birefringence data can be used to characterize clear polymer films, which are principally made of biaxial oriented polymer, as the film is being continuously fabricated on a production line. While attempting to download information, the system attempts the download techniques in priority order.