ISO/IEC 21228:2019

Information technology - Telecommunications and information exchange between systems - Coexistence mechanism for broadband powerline communication technologies

This document specifies the coexistence mechanism for various broadband powerline communication systems. By using the coexistence mechanism, possible harmful interference between different standard-based high-speed powerline communication systems can be avoided.

Technologies de l'information — Télécommunications et échange d'information entre systèmes — Mécanisme de coexistence des technologies de communication large bande sur ligne électrique

General Information

• Status: Published
• Publication Date: 23-May-2019
• ICS: 35.110 - Networking
• Technical Committee: ISO/IEC JTC 1/SC 6 - Telecommunications and information exchange between systems
• Drafting Committee: ISO/IEC JTC 1/SC 6/WG 1 - Physical and data link layers
• Current Stage: 9093 - International Standard confirmed
• Start Date: 23-May-2025
• Completion Date: 30-Oct-2025

Overview

ISO/IEC 21228:2019 defines a coexistence mechanism for broadband powerline communication (PLC) technologies. The standard specifies a coexistence protocol (CP) that enables multiple, non‑interoperable high‑speed PLC systems to share the same powerline medium without causing harmful interference. It extends existing inter-system protocols to accommodate another in‑home system while preserving backward compatibility with IEEE Std 1901 ISP behavior.

Key topics and technical requirements

• Coexistence protocol (CP): Shares time‑domain and frequency‑domain resources between different broadband PLC systems. The CP is largely aligned with the IEEE 1901 inter‑system protocol (ISP) and ITU‑T G.9972 coexistence concepts.
• Resource sharing methods: Two primary multiplexing strategies are used:
  • Time Domain Multiplex (TDM) - extended TDM resource allocation to support up to four non‑interoperable systems on the same powerline.
  • Frequency Domain Multiplex (FDM) - alternative method for splitting spectral resources among systems.
• Extended TDM schemes:
  • Utilizing TDM resources of an absent in‑home system (IH-A assumes the allocation of the first absent system in a fixed order IH‑W, IH‑O, IH‑G).
  • Utilizing TDM resources of an access system when no access or absent in‑home systems exist.
• Compatibility and detection rules:
  • IH‑A transmits ISP signals with a different periodicity (8×T) versus standard systems (4×T) so it can detect newly connected systems and relinquish resources accordingly.
  • IH‑A uses phase vectors corresponding to the first absent in‑home system as specified in IEEE 1901 tables for synchronization.

Applications and practical value

• Prevents harmful interference in environments where multiple broadband PLC standards coexist (e.g., mixed deployments of IEEE 1901, ITU‑T G.hn, ISO/IEC 12139‑1).
• Enables reliable home networking and in‑premises broadband services over existing powerline infrastructure when devices from different standards operate nearby.
• Useful for system designers and implementers who need to ensure interoperability at the coexistence layer without changing underlying PHY/MAC implementations.

Who should use this standard

• PLC equipment manufacturers implementing multi‑standard coexistence.
• Network architects and integrators deploying in‑home or access PLC solutions.
• Standards developers and test laboratories validating coexistence behavior.
• Regulators and certification bodies assessing coexistence mitigation in shared powerline environments.

Related standards

• IEEE Std 1901-2010 (ISP and TDM/FDM coexistence)
• ISO/IEC 12139‑1 (High‑speed PLC MAC/PHY)
• ITU‑T G.9960 / G.9961 (G.hn family)
• ITU‑T G.9972:2010 (Coexistence mechanism for wireline home networking)

Keywords: ISO/IEC 21228:2019, coexistence mechanism, broadband powerline communication, PLC coexistence, time domain multiplex, frequency domain multiplex, IEEE 1901, G.hn, ISP, CP.

Standards Content (Sample)

INTERNATIONAL ISO/IEC
STANDARD 21228
First edition
2019-05
Information technology —
Telecommunications and information
exchange between systems —
Coexistence mechanism for
broadband powerline communication
technologies
Technologies de l'information — Télécommunications et échange
d'information entre systèmes — Mécanisme de coexistence des
technologies de communication large bande sur ligne électrique
Reference number
©
ISO/IEC 2019
© ISO/IEC 2019
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
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Published in Switzerland
ii © ISO/IEC 2019 – All rights reserved

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Abbreviation . 1
5 Coexistence protocol . 1
5.1 General . 1
5.2 Extended TDM resource allocation utilizing resource for an absent in-home system . 2
5.3 Extended TDM resource allocation utilizing resource for access system . 3
Bibliography . 6
© ISO/IEC 2019 – All rights reserved iii

Foreword
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Commission) form the specialized system for worldwide standardization. National bodies that
are members of ISO or IEC participate in the development of International Standards through
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This document was prepared by Joint Technical Committee ISO/IEC JTC 1, Information technology,
Subcommittee SC 6, Telecommunications and information exchange between systems.
Any feedback or questions on this document should be directed to the user’s national standards body. A
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iv © ISO/IEC 2019 – All rights reserved

Introduction
ISO/IEC 12139-1 was published in July 2009. There were also standardization activities on high speed
powerline communication in other standards development organizations; IEEE P1901 WG and ITU-T
SG15. IEEE Std 1901-2010 was approved in October 2010, and G.hn(G.9960/G.9961) consented in ITU-T
in June 2010.
Since powerline is a shared medium of frequency, the different-standard-devices which use powerline
could cause harmful interference to each other when used in the same vicinity. Therefore, it is important
to study harmonized coexistence to prevent possible harmful interference between devices that adopt
standards from different standards organizations.
An IEC SMB decision 135/18 in June 2009 requested that ISO/IEC JTC1/SC 6 initiate maintenance work
rapidly to solve any coexistence problems with the G.hn(G.9960) series of ITU-T Recommendations and
any other relevant standards from the IEC or elsewhere.
To solve the coexistence problem, ISO/IEC JTC1/SC 6 established a Study Group on High Speed PLC
Harmonization (SGPLC) among High Speed PLC International Standards at their meeting in January
2010. The final goal of SGPLC was to achieve harmonized coexistence not only between ISO/IEC 12139-
1 and ITU-T G.9960 but between ISO/IEC 12139-1 and IEEE Std 1901-2010. The study report was
presented and was approved for its results.
In this document, to guarantee backward compatibility with the ISP (Inter System Protocol) of IEEE Std
1901-2010, time domain multiplex general resource allocation is extended to support another non-
interoperable in-home system such as ISO/IEC 12139-1 based powerline communication system while the
maximum number of non-interoperable systems supported at the same time remains unchanged as four.
© ISO/IEC 2019 – All rights reserved v

INTERNATIONAL STANDARD ISO/IEC 21228:2019(E)
Information technology — Telecommunications and
information exchange between systems — Coexistence
mechanism for broadband powerline communication
technologies
1 Scope
This document specifies the coexistence mechanism for various broadband powerline communication
systems. By using the coexistence mechanism, possible harmful interference between different
standard-based high-speed powerline communication systems can be avoided.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
IEEE Std 1901-2010, IEEE Standard for Broadband over Power Line Networks: Medium Access Control and
Physical Layer Specifications
3 Terms and definitions
No terms and definitions are listed in this document.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— IEC Electropedia: available at http: //www .electropedia .org/
— ISO Online browsing platform: available at http: //www .iso .org/obp
4 Abbreviation
CP coexistence protocol
FDM frequency domain multiplex
IH in-home
ISP inter-system protocol
TDM time domain multiplex
5 Coexistence protocol
5.1 General
This Clause s
...