The reader collision problem in RFID systems

In a multi-reader environment, RFID system performance will be limited by the reader collision problem. RFID readers use different channels to minimise collision. However, with limited channels, the in-channel collision will happen. Using a path loss model, this paper predicts the safe distance between the readers before collisions occur in a same channel. This paper also explores the complication caused by the introduction of Listen Before Talk (LBT) in the European Regulation, makes suggestions on how reader collision problems and LBT effects can be minimised.