IEC 62980:2022

Parasitic communication protocol for radio-frequency wireless power transmission

IEC 62980:2022 defines procedures for transferring power to non-powered IoT devices using the existing ISM band communication infrastructure and RF WPT and a protocol for a two-way, long-distance wireless network in which IoT devices and APs communicate using backscatter modulation of ISM-band signals. Three components are required for two-way, long-distance wireless communication using backscatter modulation of ISM-band signals:
• an STA that transmits wireless power and data packets to SSNs by forming ISM-band signal channels between HIE-APs,
• a battery-free SSN that changes the sensitivity of the channel signals received from the STA using backscatter modulation, and
• an HIE-AP that practically decodes the channel signals whose sensitivity was changed by the SSN.
In this document, the procedures for CW-type RF WPT using communication among these three components are specified based on application of the CSI or RSSI detection method of ISM-band communication.
This document proposes a convergence communication protocol than can deploy sensors, which can operate at low power (dozens of microwatts or less) without batteries, collect energy, and perform communication, to transmit power to SSNs using RF WPT based on parasitic communication. This method can be applied to application service areas such as domestic IoT, the micro-sensor industry, and industries related to environmental monitoring in the future.

Protocole de communication parasite pour le transfert d'énergie sans fil par rayonnement radiofréquence

L'IEC 62980:2022 définit les procédures de transfert d'énergie vers des dispositifs d'IoT au moyen de l'infrastructure de communication existante sur les bandes ISM et du WPT RF, ainsi qu'un protocole de réseau sans fil longue distance bidirectionnel qui permet aux dispositifs d'IoT et aux points d'accès de communiquer par modulation de rétrodiffusion des signaux sur les bandes ISM. La communication sans fil longue distance bidirectionnelle fondée sur la modulation de rétrodiffusion des signaux sur les bandes ISM exige trois éléments:
• une STA qui assure le transfert sans fil de l'énergie et des paquets de données vers les SSN en créant des canaux de signaux dans les bandes ISM entre HIE-AP ;
• un SSN sans batterie qui modifie, par modulation de rétrodiffusion, la sensibilité des signaux de canal reçus depuis la STA ; et
• un HIE-AP qui décode de manière pratique les signaux du canal dont la sensibilité a été modifiée par le SSN.
Dans le présent document, les procédures de WPT RF de type CW qui utilisent la communication entre ces trois éléments sont spécifiées à partir de l'application d'une méthode de détection des CSI ou du RSSI de la communication sur les bandes ISM.
Le présent document propose un protocole de communication convergent qui peut déployer des capteurs, lesquels peuvent fonctionner à faible puissance (quelques dizaines de microwatts ou moins) sans batteries, collecter de l'énergie et assurer une communication, afin d'alimenter des SSN au moyen d'un WPT RF fondé sur une communication parasite. Cette méthode pourra être appliquée ultérieurement à des services d'application tels que l'IoT domestique, l'industrie des microcapteurs et les industries impliquées dans la surveillance de l'environnement.

General Information

• Status: Published
• Publication Date: 27-Sep-2022
• ICS: 29.240.99 - Other equipment related to power transmission and distribution networks
• Technical Committee: TA 15 - Wireless Power Transfer
• Drafting Committee: WG 2 - TC 100/TA 15/WG 2
• Current Stage: PPUB - Publication issued
• Start Date: 14-Oct-2022
• Completion Date: 28-Sep-2022

Standards Content (Sample)

IEC 62980
®

Edition 1.0 2022-09
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE


Parasitic communication protocol for radio-frequency wireless power
transmission

Protocole de communication parasite pour le transfert d'énergie sans fil par
rayonnement radiofréquence

IEC 62980:2022-09(en-fr)

---------------------- Page: 1 ----------------------
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IEC 62980

®


Edition 1.0 2022-09




INTERNATIONAL



STANDARD




NORME


INTERNATIONALE











Parasitic communication protocol for radio-frequency wireless power

transmission



Protocole de communication parasite pour le transfert d'énergie sans fil par

rayonnement radiofréquence
















INTERNATIONAL

ELECTROTECHNICAL

COMMISSION


COMMISSION

ELECTROTECHNIQUE


INTERNATIONALE




ICS 29.240.99 ISBN 978-2-8322-5700-5




Warning! Make sure that you obtained this publication from an authorized distributor.

Attention! Veuillez vous assurer que vous avez obtenu cette publication via un distributeur agréé.

® Registered trademark of the International Electrotechnical Commission
Marque déposée de la Commission Electrotechnique Internationale

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– 2 – IEC 62980:2022 © IEC 2022
CONTENTS
FOREWORD . 5
INTRODUCTION . 7
1 Scope . 8
2 Normative references . 8
3 Terms, definitions and abbreviated terms . 8
3.1 Terms and definitions . 9
3.2 Abbreviated terms . 9
4 Overview . 10
5 Communication procedures for RF WPT . 11
5.1 General . 11
5.2 Communication procedures for parasitic downlink communication . 12
5.3 Communication procedures for parasitic uplink communication . 13
5.4 Backscatter downlink/uplink data flow . 14
5.5 WPT process . 15
6 Physical layer . 16
6.1 Modulation/coding method . 16
6.1.1 General . 16
6.1.2 Downlink modulation method . 16
6.1.3 Uplink modulation method . 17
6.1.4 Downlink coding method . 17
6.1.5 Uplink coding method . 18
6.2 Frame structure . 18
6.2.1 General . 18
6.2.2 Downlink frame structure . 18
6.2.3 Uplink frame structure . 20
7 Datalink layer . 21
7.1 Message definition . 21
7.1.1 General . 21
7.1.2 Select step . 24
7.1.3 Inventory step . 26
7.1.4 Access step . 29
7.2 Data encoding . 31
7.2.1 General . 31
7.2.2 FM0 encoding . 31
7.2.3 Miller encoding . 32
8 RF WPT control protocol. 33
8.1 Wireless charging architecture . 33
8.1.1 General . 33
8.1.2 Power control purpose of RF WPT . 34
8.1.3 HIE-AP operation control . 34
8.1.4 SSN operation control . 35
8.2 RF WPT process . 36
8.2.1 General . 36
8.2.2 General WPT management . 37
8.2.3 SSN control . 38
8.2.4 SSN static parameter . 39

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IEC 62980:2022 © IEC 2022 – 3 –
8.2.5 SSN dynamic parameter . 40
Annex A (informative)  Regulation and certification . 42
Bibliography . 43

Figure 1 – Usage of RF-WPT . 10
Figure 2 – RF-WPT structure of using parasitic Wi-Fi communication technology . 11
Figure 3 – Parasitic downlink/uplink communication procedures . 12
Figure 4 – Specific parasitic downlink communication procedures . 13
Figure 5 – Specific parasitic uplink communication procedures . 14
Figure 6 – Data flow during parasitic downlink/uplink communication . 15
Figure 7 – RF WPT access procedures . 15
Figure 8 – RF WPT control protocol . 16
Figure 9 – PIE method packet configuration . 17
Figure 10 – Modulation and coding of the downlink preamble . 17
Figure 11 – Modulation and coding of the downlink preamble . 18
Figure 12 – Modulation and coding of the uplink preamble . 18
Figure 13 – Modulation and coding of the uplink payload . 18
Figure 14 – Physical layer structure of the downlink frame . 19
Figure 15 – Physical layer structure of the uplink frame . 20
Figure 16 – Model of command transmission between the STA and SSN . 22
Figure 17 – Diagram of sequential command transmission between the STA and SSN. 22
Figure 18 – SSN memory structure . 24
Figure 19 – Message exchange in the select step . 25
Figure 20 – CRC-16 circuit example. 26
Figure 21 – Message exchange method of the inventory step . 27
Figure 22 – Basic functions for FM0 encoding . 31
Figure 23 – State diagram for FM0 encoding generation . 31
Figure 24 – Basic functions for Miller encoding . 32
Figure 25 – State diagram for FM0 encoding generation . 32
Figure 26 – Encoding theory combining basic Miller functions . 33
Figure 27 – Basic configuration of the RF wireless charging network of the proposed

standard . 34
Figure 28 – HIE-AP operation in RF WPT in the proposed standard . 35
Figure 29 – SSN operation in RF WPT in the proposed standard . 35
Figure 30 – Operating range of the rectified battery voltage . 36
Figure 31 – RF WPT information acquisition and control protocol of the proposed
standard . 37

Table 1 – Downlink preamble structure . 19
Table 2 – Downlink payload structure . 19
Table 3 – Downlink frame check CRC . 20
Table 4 – Uplink preamble structure . 20
Table 5 – Uplink frame detection field structure . 21
Table 6 – Downlink payload structure . 21

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– 4 – IEC 62980:2022 © IEC 2022
Table 7 – CMD list . 23
Table 8 – Responses for each CMD . 23
Table 9 – Select CMD . 25
Table 10 – Valid response . 26
Table 11 – Query CMD field . 27
Table 12 – QueryRep CMD field . 28
Table 13 – QueryAdj CMD field . 28
Table 14 – Valid_Query response field . 28
Table 15 – Ack CMD field . 29
Table 16 – Valid_Ack response field list . 29
Table 17 – Read CMD field . 30
Table 18 – Data field of the response to the read command . 30
Table 19 – Write CMD field . 30
Table 20 – Data field of the response to the write command . 30
Table 21 – WPT CMD field . 37
Table 22 – WPT sub-CMD list . 38
Table 23 – SSN control field . 38
Table 24 – Detailed WPT field description . 38
Table 25 – Response to the SSN control CMD . 39
Table 26 – SSN static parameter field . 39
Table 27 – Rectifier maximum power field . 39
Table 28 – Rectifier minimum constant voltage . 39
Table 29 – Rectifier maximum constant voltage . 39
Table 30 – Rectifier minimum constant voltage . 40
Table 31 – SSN dynamic parameter field . 40
Table 32 – Rectifier dynamic voltage field . 40
Table 33 – Rectifier dynamic current field . 40
Table 34 – Output dynamic voltage of the battery terminal . 40
Table 35 – Output dynamic current of the battery terminal . 41
Table 36 – Battery temperature of the SSN . 41
Table 37 – SSN critical state field . 41
Table 38 – Rectifier desired minimum voltage . 41

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IEC 62980:2022 © IEC 2022 – 5 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________

PARASITIC COMMUNICATION PROTOCOL FOR
RADIO-FREQUENCY WIRELESS POWER TRANSMISSION

FOREWORD
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IEC 62980 has been prepared by technical area 15: Wireless power transfer, of IEC technical
committee 100: Audio, video and multimedia systems and equipment. It is an International
Standard.
The text of this International Standard is based on the following documents:
Draft Report on voting
100/3797/FDIS 100/3818/RVD

Full information on the voting for its approval can be found in the report on voting indicated in
the above table.
The language used for the development of this International Standard is English.
This document was drafted in accordance with ISO/IEC Directives, Part 2, and developed in
accordance with ISO/IEC Directives, Part 1 and ISO/IEC Directives, IEC Supplement, available
at www.iec.ch/members_experts/refdocs. The main document types developed by IEC are
described in greater detail at www.iec.ch/publications.

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– 6 – IEC 62980:2022 © IEC 2022
The committee has decided that the contents of this document will remain unchanged until the
stability date indicated on the IEC website under webstore.iec.ch in the data related to the
specific document. At this date, the document will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.

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IEC 62980:2022 © IEC 2022 – 7 –
INTRODUCTION
This document provides a parasitic backscatter communication protocol for battery-free
internet-of-things (IoT) devices and sensors for radio-frequency (RF) wireless power
transmission (WPT) without additional infrastructure.

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– 8 – IEC 62980:2022 © IEC 2022
PARASITIC COMMUNICATION PROTOCOL FOR
RADIO-FREQUENCY WIRELESS POWER TRANSMISSION



1 Scope
This document defines procedures for transferring power to non-powered IoT devices using the
existing ISM band communication infrastructure and RF WPT and a protocol for a two-way,
long-distance wireless network in which IoT devices and APs communicate using backscatter
modulation of ISM-band signals. Three components are required for two-way, long-distance
wireless communication using backscatter modulation of ISM-band signals:
• an STA that transmits wireless power and data packets to SSNs by forming ISM-band signal
channels between HIE-APs,
• a battery-free SSN that changes the sensitivity of the channel signals received from the STA
using backscatter modulation, and
• an HIE-AP that practically decodes the channel signals whose sensitivity was changed by
the SSN.
In this document, the procedures for CW-type RF WPT using communication among these three
components are specified based on application of the CSI or RSSI detection method of ISM-
band communication.
This document proposes a convergence communication protocol than can deploy sensors,
which can operate at low power (dozens of microwatts or less) without batteries, collect energy,
and perform communication, to transmit power to SSNs using RF WPT based on parasitic
communication. This method can be applied to application service areas such as domestic IoT,
the micro-sensor industry, and industries related to environmental monitoring in the future.
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.
IEC 63006:2019, Wireless Power Transfer (WPT) – Glossary of terms
IEC TR 63239:2020, Radio frequency beam wireless power transfer (WPT) for mobile devices
3 Terms, definitions and abbreviated terms
For the purposes of this document, the following terms and definitions apply.
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

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IEC 62980:2022 © IEC 2022 – 9 –
3.1 Terms and definitions
3.1.1
BCU
backscatter communication unit
device that responds to a command from an STA with backscatter through load modulation, and
that enables communication without power
3.1.2
BU
battery unit
battery and circuit capable of receiving wireless power to support the operations of devices and
sensors
3.1.3
HIE-AP
hybrid information and energy access point
device that decodes the channel signals whose sensitivity was changed by the SSN into digital
signals (0 or 1)
Note 1 to entry: An HIE-AP forms an STA and ISM-band channels for communication, detects the CSI or RSSI level
of the response using backscatter from the SSN, and transmits the response data from the SSN to the STA. It also
transmits CW-type power to the SSN for RF WPT.
3.1.4
impedance modulation
method of changing the sensitivity of the received signal from the channel between the STA
and HIE-AP by using backscatter modulation in the SSN according to the data
3.1.5
SSN
smart sensor node
device that changes the sensitivity of the received channel signals using backscatter modulation
Note 1 to entry: SSNs include IoT devices, wearable devices, and micro-sensors.
Note 2 to entry: An SSN consists of a backscatter communication unit (BCU) that supports communication without
power, a smart sensor unit (SSU) that identifies various sensors, and a battery unit (BU) that receives WPT.
3.1.6
SSU
smart sensor unit
sensor that can be attached to an SSN.
Note 1 to entry: Each sensor requires a different amount of power.
3.1.7
STA
station
device that can perform communication by occupying an ISM-band channel
Note 1 t
...