A vertical blind assembly module includes a head rail unit with opposite sides and a unit axis extending between the sides, a housing and an axle pivotally connecting the housing to the head rail unit so that the housing can pivot about a pivot axis that is perpendicular to the unit axis. The self-tracking sensor mechanism has a link pivotally attached to a body portion of the pig and a spring for urging the link in a direction away from the body portion of the pig and toward the wall of the pipeline being inspected. Each annulus has an outer diameter larger than the inner diameter of a cylindrical housing of the filtration system. Based on the start RBG# and end RBG# output from RIV decoding unit and the boundaries of the allocations of respective RIVs output from allocation boundary setting unit, transmission bandwidth determination unit determines, as allocated bandwidths, the bandwidths that are indicated by a plurality of RIVs and are not overlapped with each other.