In this work, we develop a CSMA-based MAC protocol to avoid reader-reader and reader-tag collisions in a dense RFID network. The network is implemented using mote-based RFID readers. To implement the MAC protocol, we develop an appropriate carrier sensing circuit using an RFID tag as an antenna and the mote as an apparatus to sample received signal strength. We have augmented a commercially available OEM RFID module with such carrier sensing capability and interfaced it with motes. Performance evaluation shows much superior performance relative to a naive and a randomized protocol in dense deployment environments both in regards to accuracy and time per tag read.

Shweta Jain, Samir R Das,”Collision Avoidance in Multi-Reader RFID Networks”,Accepted in The First ACM International Workshop on Wireless Network Testbeds, Experimental evaluation and CHaracterization (WiNTECH 2006) in conjunction with ACM MobiCom 2006 wintech.ppt

• D.W.Engels and S. E Sarma, The Reader Collision Problem,Systems, Man and Cybernetics, 2002 IEEE International Conference on Oct 2002.
• Waldrop, J. Engels, D.W. Sarma, S.E. Colorwave: an anticollision algorithm for the reader collision problem, Communications, 2003. ICC '03. IEEE International Conference on.
• RFID Journal http://www.rfidjournal.com

• Faculty: Samir Das
• Graduate Student: Shweta Jain

Please send all questions and comments to Shweta Jain at email.