System and methods for optimizing communications between an RFID reader
and a population of tags are described. To minimize the amount of data
exchanges, the reader and tags use non-sequential bit string or byte
masking. In non-sequential bit string masking, the reader transmits an
interrogation mask having a plurality of non-sequential sub-masks to the
tags. During subsequent collection of the identification sequence, the
reader and tags only exchange the non-masked bit positions. The
interrogation mask can be determined using superposition processing,
historical tendencies, or known identification and/or subset of
identification ranges. During superposition processing, the reader
determines whether a bit position contains a single value or multiple
values for tags in the tag population. If the bit position contains a
single value, the bit position is designated as masked. If the bit
position contains multiple values, the bit position is designated as
non-masked.