The UN standard UN/CEFACT "Smart Containers" can be found here - https://www.unece.org/fileadmin/DAM/cefact/brs/BRS-SmartContainer_v1.0.pdf
The related DCSA specifications can be found here - https://dcsa.org/initiatives/iot-gateway-connectivity-interface-standards/
https://www.linkedin.com/posts/digital-container-shipping-association-dcsa_dcsa-press-release-iot-standards-for-container-activity-6673462139732148224-XMzr https://www.linkedin.com/posts/digital-container-shipping-association-dcsa_seven-businesses-now-compliant-with-new-dcsa-activity-6692081107292319744-Lgx3
Few related news links :- https://www.cma-cgm.com/services/smart-containers https://www.apl.com/our-offerings/value-added-services/traxens