10 sats \ 0 replies \ @orthzar 26 Apr 2023 \ parent \ on: LTESniffer: An open-source LTE downlink/uplink eavesdropper [pdf] tech
One such device was the Neo900, which had the baseband as a separate chip that the CPU could turn off at any time. Unfortunately, development stopped sometime in 2018. It seems like they might have shipped some units to customers, but I haven't been able to confirm that for sure.