System and methods for receive processing of a burst communication system where co-channel signals collide in a receiver. The barrier drive ring is rotatable in opposite directions so as to drive the lens barrier member through the neutralizing spring between the open position and the closed position. Each thin waveguide operates with one propagating mode. The characteristics may vary from one lateral zone of a PTFE layer to a second lateral zone of a PTFE layer. The difference amount is queue-specific and is a running difference between calculated and actual queue servicing times. The anchor is collapsible for endoscopic delivery and removal.