
276 RFID and Auto-ID in Planning and Logistics
increasing distance from tag to each side of the portal. Therefore, the estimation of an antenna’s
physical coordinates should be done according to the features and requirements of the RFID and
warehouse system. The data that are collected by the antenna should be accompanied by an indi-
cation of where in space that data were reported. The bandwidth and limitations of the antenna
network make it necessary for data location coordinates of the physical location of the portal door in
a warehouse to be established. In many cases, location itself gives the range of data that should be
sensed—locali