Published in Pastos, N., & Viswanathan, R. (2000). A modified grouped-tag TDMA access protocol for radio frequency identification networks. IEEE Wireless Communications and Networking Conference, 2000 (WCNC. 2000), v. 2, 512-516. doi: 10.1109/WCNC.2000.903905 ©2000 IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE. This material is presented to ensure timely dissemination of scholarly and technical work. Copyright and all rights therein are retained by authors or by other copyright holders. All persons copying this information are expected to adhere to the terms and constraints invoked by each author's copyright. In most cases, these works may not be reposted without the explicit permission of the copyright holder.


In this paper we describe a new medium access protocol termed as the modified grouped-tag TDMA protocol (MGTDMA) for networking radio frequency identification tags. It is known that the previously proposed grouped-tag TDMA (GTDMA) protocol performs very well under the conditions of uniform destination distribution and not so well for heterogeneous traffic conditions. The MGTDMA differs from GTDMA in the sense that MGTDMA allows groups experiencing high traffic to steal (cooperatively) from low traffic groups at regular time intervals. Performance of an access scheme is assessed in terms of average packet delay and average energy consumption. Approximate analytical equation for average delay is derived. More accurate estimates for delay are obtained through simulation studies. We compare the performances of MGTDMA, GTDMA, and a pseudo random protocol and show the usefulness of the new scheme.