Colorwave is a time division multiple access (TDMA) approach for collision resolution among radio frequency identification (RFID) readers. As RFID technology is widely used, several approaches for collision resolution have been studied. TDMA is one of the most simple and yet efficient solutions. In the Colorwave approach, different readers can have different time slots so that more successful readings are available.

The motivation of this paper is to introduce a probabilistic approach to Colorwave. When a probabilistic approach is applied to another TDMA solution called distributed color selection (DCF), which uses a constant number of time slots for all readers, the collision ratio is reduced. A main challenge of probabilistic Colorwave (PCW) compared to probabilistic DCF is that it is difficult for readers to stay in a steady state avoiding collision since a pair of readers will change their time slot colors on every round and the relative color will keep changing. To overcome this challenge, this paper introduces three parameters, including thresholds and a stabilization period.

To evaluate the proposed PCW, the authors set various numbers of neighbors from five to 50. As addressed in the paper, the proposed PCW is applicable to a warehouse where multiple RFID readers can collide. The authors note that PCW will benefit in a situation where there are no more than 20 readers. However, the effect of the proposed PCW will be insignificant because the interfering range will be shorter than 200 meters in a warehouse where there are lots of steel shelves, piles of goods, and propagation barriers.