Batteryless backscatter sensor networks—Part I: challenges with (really) simple tagsBatteryless backscatter sensor networks—Part I: challenges with (really) simple tags Peer-Reviewed Journal Publication Δημοσίευση σε Περιοδικό με Κριτές 2025-04-282023enBackscatter radio only requires a simple switch, terminating the tag antenna between (at least) two loads. However, recent detection in ambient backscatter sensor networks assumes that the tag is receiver-equipped, able to synchronize its backscattering with the illuminating (ambient) transmission. Additional challenges with simple, potentially receiver-less, backscattering tags include: lack of cooperation with the legacy, ambient illuminator, asynchronous channel estimation, tag frame synchronization, energy harvesting for batteryless tag operation and multiple access. Part I addresses asynchronous channel estimation and detection with digital ambient signals and concrete analysis; Part II partially addresses all challenges with analog ambient signals and practical deployment.The research work was supported by the Hellenic Foundation for Research and Innovation (H.F.R.I.) under the “First Call for H.F.R.I. Research Projects to support Faculty members and Researchers and the Procurement of High-cost research equipment” (Project Number: 2846).http://creativecommons.org/licenses/by/4.0/IEEE Communications Letters273763-767 Alevizos Panagiotis Αλεβιζος Παναγιωτης Vougioukas Georgios Βουγιουκας Γεωργιος Bletsas Aggelos Μπλετσας Αγγελος Institute of Electrical and Electronics Engineers Backscatter radio RFID Sensor networks