A reliable cardinality estimation for missing tags over a noisy channel

Abstract

Estimating the number of missing tags is an important issue for administration of RFID systems. The existing cardinality estimation schemes assume a perfect tag-to-reader channel to estimate the number of missing tags. As the wireless tag-to-reader channel is not error-free, this paper considers the problem of estimating the number of missing tags over a noisy tag-to-reader channel. Given the symmetric bit error rate as input , the RMTE (Reliable Missing Tag Estimation) protocol presented in this paper estimates the number of missing tags by checking whether the first assumed non-empty slot in the virtual frame becomes an empty slot in the response frame. Then we analyze the RMTE protocol under the random error model to demonstrate that the specified accuracy and reliable requirements can be satisfied by a suitable choice of the number of rounds to be executed. Compared with the related cardinality estimation schemes for missing tags, simulations results show that the presented RMTE scheme can yield an accurate and reliable estimation for the number of missing tags under the random error model.