IEC 62149-5:2020 is available as IEC 62149-5:2020 RLV which contains the International Standard and its Redline version, showing all changes of the technical content compared to the previous edition.IEC 62149-5:2020 specifies performance on the transceiver modules for asynchronous-transfer-mode passive optical network (ATM-PON) systems recommended by the International Telecommunication Union (ITU) in ITU-T Recommendation G.983.1. This third edition cancels and replaces the second edition published in 2009 and constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition: - description of types in Clause 4 has been removed; - titles of reference documents have been updated.