ISO/IEC 4005-4:2023

Telecommunications and information exchange between systems — Unmanned aircraft area network (UAAN) — Part 4: Physical and data link protocols for video communication

This document specifies communication protocols for the physical and data link layer of video communication, which is a wireless distributed communication network for units related with unmanned aircrafts (UAs) in level II. This document describes video communication, which is one-to-one communication that transmits video from a UA to a video receiver. For the specific use of video communication, video can be transmitted from a UA to multiple receivers.

Télécommunications et échange d'information entre systèmes — Réseau de zone de drones (Unmanned aircraft area network - UAAN) — Partie 4: Protocoles de liaison de données et physiques pour la communication vidéo

General Information

• Status: Published
• Publication Date: 21-Mar-2023
• ICS: 35.100.10 - Physical layer
• ICS: 35.100.20 - Data link layer
• ICS: 49.020 - Aircraft and space vehicles in general
• 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: 6060 - International Standard published
• Start Date: 22-Mar-2023
• Due Date: 09-Feb-2023
• Completion Date: 22-Mar-2023

Standards Content (Sample)

INTERNATIONAL ISO/IEC
STANDARD 4005-4
First edition
2023-03
Telecommunications and information
exchange between systems —
Unmanned aircraft area network
(UAAN) —
Part 4:
Physical and data link protocols for
video communication
Télécommunications et échange d'information entre systèmes —
Réseau de zone de drones (Unmanned aircraft area network -
UAAN) —
Partie 4: Protocoles de liaison de données et physiques pour la
communication vidéo
Reference number
ISO/IEC 4005-4:2023(E)
© ISO/IEC 2023

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ISO/IEC 4005-4:2023(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO/IEC 2023
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: [phone]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland
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ISO/IEC 4005-4:2023(E)
Contents Page
Foreword .v
Introduction . vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Abbreviated terms . 1
5 Physical layer . 2
5.1 Channel and frame structure for data channel . 2
5.1.1 The number of data channels and bandwidth . 2
5.1.2 Frame structure . 3
5.1.3 Slot transmit time mask . . 3
5.1.4 Sub channels . 4
5.1.5 Dedicated subchannels . 5
5.2 Channel and frame structure for tone channel . 5
5.2.1 General . 5
5.2.2 Slot transmit power . 5
5.3 Encoding procedure . 5
5.3.1 CRC encoding . 6
5.3.2 Turbo encoding . 6
5.3.3 Rate matching . 9
5.3.4 Interleaving . 9
5.3.5 Modulation mapping . 9
5.3.6 Burst mapping . 9
5.3.7 Pulse mapping . 11
5.4 Physical layer procedure .12
5.4.1 Synchronization .12
5.4.2 Subchannel power .12
5.4.3 Measurements .12
5.4.4 Coexistence operation .12
6 Data link layer .13
6.1 General .13
6.2 Channel mapping and measurements. 14
6.2.1 General . 14
6.2.2 Mapping of communication resources and subslot sets. 14
6.2.3 Interference power calculation . 15
6.2.4 Subchannel map . 16
6.3 Subchannel negotiation for allocation . 16
6.3.1 General . 16
6.3.2 Subchannel negotiation using shared channel . 20
6.3.3 Subchannel negotiation using dedicated slot . 23
6.3.4 Subchannel negotiation using CSCH . 24
6.4 Subchannel allocation and generated link confirmation . 25
6.4.1 General . 25
6.4.2 Subchannel resource allocation competition . 26
6.4.3 Generated link confirmation . 27
6.4.4 Broadcasting video subchannel (VSCH) information being allocated or
occupied .28
6.5 Subchannel occupation and collision management .29
6.5.1 General .29
6.5.2 Power control in occupation stage .29
6.5.3 Subchannel occupation and return method.30
6.5.4 Collision tone transmission and collision management .30
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ISO/IEC 4005-4:2023(E)
6.5.5 Parsing block for video channel .30
6.6 Reallocation . . 30
6.6.1 General .30
6.6.2 Reallocation decision . 31
6.6.3 Subchannel reallocation procedure . 32
6.7 Data exchange . 33
6.7.1 General . 33
6.7.2 Data packet format .34
6.8 Synchronization . 35
6.9 Data link layer security . 35
6.10 Interface with upper layer. 37
6.10.1 General . 37
6.10.2 Initialization interface. 37
6.10.3 Dynamic interface . 42
6.11 Interface with other communication layer .46
6.11.1 General .46
6.11.2 Interface with SC .46
6.11.3 Interface with CC . 47
Annex A (normative) Turbo internal interleaver table .50
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ISO/IEC 4005-4:2023(E)
Foreword
ISO (the International Organization for Standardization) and IEC (the International Electrotechnical
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 technical
committees established by the respective organization to deal with particular fields of technical
activity. ISO and IEC technical committees collaborate in fields of mutual interest. Other international
organizations, governmental and non-governmental, in liaison with ISO and IEC, also take part in the
work.
The procedures used to develop this document and those intended for its further maintenance
are described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria
needed for the different types of document should be noted. This document was drafted in
accordance with the editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives or
www.iec.ch/members_experts/refdocs).
Attention is drawn to the possibility that some of the elements of this document may be the subject
of patent rights. ISO and IEC shall not be held responsible for identifying any or all such patent
rights. Details of any patent rights identified during the development of the document will be in the
Introduction and/or on the ISO list of patent declarations received (see www.iso.org/patents) or the IEC
list of patent declarations received (see https://patents.iec.ch).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to
the World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see
www.iso.org/iso/foreword.html. In the IEC, see www.iec.ch/understanding-standards.
This document was prepared by Joint Technical Committee ISO/IEC JTC 1, Information technology,
Subcommittee SC 6, Telecommunications and information exchange between systems.
A list of all parts in the ISO/IEC 4005 series can be found on the ISO and IEC websites.
Any feedback or questions on this document should be directed to the user’s national standards
body. A complete listing of these bodies can be found at www.iso.org/members.html and
www.iec.ch/national-committees.
v
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ISO/IEC 4005-4:2023(E)
Introduction
Unmanned aircrafts (UAs) operating at low altitudes will provide a variety of commercial services in
the near future. UAs that provide these services are distributed in the airspace. In level II, many people
operate their own UAs without the assignment of communication channels from a central control
centre.
This document describes video communication, which is a wireless distributed communication. Video
communication allows UAs distributed over the airspace to transmit video without serious interference
to the relevant video receiver which is usually a controller. The channels used for video communication
have a multi-channel structure, which enables UA and video receiver pairs to independently use the
occupied communication link. A wireless distributed communication described by this document is
intended to be used in licensed frequency bands.
The ISO/IEC 4005 series consists of the following four parts:
ISO/IEC 4005-1: To support various services for UAs, it describes a wireless distributed communication
model and the requirements that this model shall satisfy.
ISO/IEC 4005-2: It describes communication in which all units involved in UA operation can broadcast
or exchange information by sharing communication resources with each other.
ISO/IEC 4005-3: It describes the control communication for the controller to control the UA.
ISO/IEC 4005-4 (this document): It describes video communication for UAs to send video to a controller.

The International Organization for Standardization (ISO) and International Electrotechnical
Commission (IEC) draw attention to the fact that it is claimed that compliance with this document may
involve the use of patents.
ISO and IEC take no position concerning the evidence, validity and scope of these patent rights.
The holders of these patent rights have assured ISO and IEC that they are willing to negotiate licences
under reasonable and non-discriminatory terms and conditions with applicants throughout the world.
In this respect, the statements of the holders of these patent rights are registered with ISO and IEC.
Information may be obtained from the patent database available at www.iso.org/patents.
Attention is drawn to the possibility that some of the elements of this document may be the subject
of patent rights other than those in the patent database. ISO and IEC shall not be held responsible for
identifying any or all such patent rights.
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INTERNATIONAL STANDARD ISO/IEC 4005-4:2023(E)
Telecommunications and information exchange between
systems — Unmanned aircraft area network (UAAN) —
Part 4:
Physical and data link protocols for video communication
1 Scope
This document specifies communication protocols for the physical and data link layer of video
communication, which is a wireless distributed communication network for units related with
unmanned aircrafts (UAs) in level II.
This document describes video communication, which is one-to-one communication that transmits
video from a UA to a video receiver. For the specific use of video communication, video can be
transmitted from a UA to multiple receivers.
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.
ISO/IEC 4005-1, Telecommunications and information exchange between systems — Unmanned aircraft
area network (UAAN) — Part 1: Communication model and requirements
ISO/IEC 4005-2, Telecommunications and information exchange between systems — Unmanned aircraft
area network (UAAN) — Part 2: Physical and data link protocols for shared communication
ISO/IEC 4005-3, Telecommunications and information exchange between systems — Unmanned aircraft
area network (UAAN) — Part 3: Physical and data link protocols for control communication
ISO 21384-4, Unmanned aircraft systems — Part 4: Vocabulary
3 Terms and definitions
For the purposes of this document, the terms and definitions defined in ISO/IEC 4005-1, ISO/IEC 4005-2,
ISO/IEC 4005-3, ISO 21384-4 and the following apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
4 Abbreviated terms
CC Control Communication
CB Coding Block
CRC Cyclic Redundancy Check
1
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ISO/IEC 4005-4:2023(E)
CSCH Control Subchannel
DL Data Link
DLL Data Link Layer
DQPSK Differential Quadrature Phase Shift Keying
DS Dedicated Slot
FN Frame Number
GF Galois Field
PCCC Parallel Concatenated Convolutional Code
PB Parsing Block
PH Parsing Header
PKH Packet Header
PN Pseudo Noise
SA Source Address
SC Shared Communication
SRRC Square Root Raised Cosine
TSB Tone Slot Block
UTC Coordinated Universal Time
VC Video Communication
VSCH Video Subchannel
5 Physical layer
5.1 Channel and frame structure for data channel
5.1.1 The number of data channels and bandwidth
The number of data channels is L. L is greater than or equal to one. The bandwidth of one data channel
is 5 MHz as shown in Figure 1. The L is determined in the upper layer.
Figure 1 — Data channels in frequency region
2
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ISO/IEC 4005-4:2023(E)
5.1.2 Frame structure
The frame length of the data channel is 1 sec and consists of 250 slots. The one slot time T is 4 ms. A
s
data slot block has 2 slots. Therefore, there are 125 data slot blocks in one frame, and the data slot block
is 8 ms in length as shown in Figure 2. The frame number, FN changes from 0 to 59 in a 1 min interval,
and has the same value as the second of the current time.
a
1 frame, T = 1 second = 250 T .
f s
b
1 slot, T = 4 ms.
s
c
1 slot block, T = 8 ms = 2 T .
sb s
Figure 2 — Data channel frame structure
5.1.3 Slot transmit time mask
The transmission time mask of a slot is as shown in Figure 3.
Key
T 0 μs
0
T , T , T , T symbol offset from T
1 2 3 4 0
a
4 ms.
b
Modulated signal.
Figure 3 — The transmission time mask of a slot
T , T , T , T are symbol offsets from T and symbol time is 1/2688000 sec. Each value is as follows: T is
1 2 3 4 0 1
8, T is 10380, T is 10388, T is 10752.
2 3 4
T is 0 μs as the start time of the slot and the power amplifier is gated on and unmodulated fine signals
0
begin to be transmitted. T is an offset at which modulation signal transmission starts. T is an offset
1 2
at which the transmission of the modulated signal ends. T is an offset at which the power amplifier is
3
gated off, and transmission of unmodulated fine signals is stopped. The transmit power of T to T , T to
0 1 2
T shall be at least 50 dB less than the modulation signal transmit power.
3
3
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ISO/IEC 4005-4:2023(E)
5.1.4 Sub channels

a
V
x
b
V
x,0
c
V
x,1
d
V
x,8
e
V
x,9
Figure 4 — Sub channel structure of video communication in even frame
One data channel consists of 10 subchannels as shown in Figure 4. Subchannel y of video channel x is
composed of the following slot set.
V = S , S , S , …, S
x,y x,z x,z+10 x,z+20 x,z+240
ye, venframe
z= (1)
yy+−12(mod )/22× , oddframe
 
 
where
y is subchannel number, y=0, 1, …, 9;
S is slot z of video channel x.
x,z
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ISO/IEC 4005-4:2023(E)
The subchannel consists of 25 slots, the i-th slot resource of the subchannel y of the channel x is indicated
by SR , and the subchannel y of frequency channel x is indicated by V . Therefore, V is as follows:
x,y,i x,y x,y
V = SR , SR , …, SR (2)
x,y x,y,0 x,y,1 x,y,24
where SR  is i-th slot resource of subchannel y of channel x, i=0, …, 24.
x,y,i
All slots of video channel are downlink.
5.1.5 Dedicated subchannels
The upper layer can predetermine one or several subchannels as dedicated subchannels. In this case,
the tone subslot set mapped with the dedicated subchannel is not used as a competition tone and can be
used for other purposes.
Dedicated subchannel information is received from an upper layer through UPtoDL.
InfoDedicatedChannel.
5.2 Channel and frame structure for tone channel
5.2.1 General
The tone channel of video communication means a competitive tone channel. The tone channel used
for video communication resource allocation and the tone channel used for control communication
resource allocation are the same channel (see ISO/IEC 4005-3).
5.2.2 Slot transmit power
The maximum transmission power PmaxTCH of the tone slot mapped to the video subchannel (VSCH)
is received as UPtoDL.InfoPowerParamVCH from the upper layer. The power of the tone subslot signal
is determined by adding the PTX_VCHTCH_differ value to the transmission power of the mapped VSCH.
5.3 Encoding procedure
The encoding follows the following procedure. CRC encoding, turbo coding, rate matching, interleaving,
modulation mapping, burst mapping, and pulse mapping are performed in this order as shown in
Figure 5.
Figure 5 — Encoding procedure
The number of symbols according to each encoding stage is shown in Table 1, where the encoding
input consists of two code blocks, CB0 and CB1 as shown in Figure 14. Each code block undergoes CRC
encoding, turbo coding, rate matching, interleaving, and modulation mapping processes, respectively.
The length of each code block in these processes is 4094, 4928, 9868, 9856, 9856, and 4928. The two
code blocks are merged into one burst during burst mapping.
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ISO/IEC 4005-4:2023(E)
Table 1 — Number of symbols at each encoding stage
Stage Number of symbols
a 4904 × 2 (binary)
b 4928 × 2 (binary)
c 9868 × 2 (binary)
d 9856 × 2 (binary)
e 9856 × 2 (binary)
f 4928 × 2 (complex)
g 10364 (complex)
h 10372 × OS (complex)
5.3.1 CRC encoding
The input bits are defined as a , a , a , a , …, a and parity bits as p , p , p , p , …, p where A represents
0 1 2 3 A-1 0 1 2 3 23
the number of input sequences. Parity bits are generated through CRC generation polynomial as follows.
24 22 6 5
g (D) = D + D + D + D + D + 1 (3)
CRC
The encoding performed through the cyclic generator polynomials has a systematic form as follows.
The resulting polynomial has zero remainder when it is divided by g (D) on GF(2).
CRC
A+23 A+22 24 23 22 1
a D + a D + … + a D + p D + p D + … + p D + p (4)
0 1 A-1 0 1 22 23
After CRC insertion, bits are represented by b , b , b , b , …, b (where B = A + 24), and the relationship
0 1 2 3 B-1
between a and b is as follows.
k k
af, orkA=−01,,,21,
k
b = (5)
k
Pf, orkA=+,,,AA12++,A 23
kA−
5.3.2 Turbo encoding
The turbo encoder consists of Parallel Concatenated Convolutional Code (PCCC) with two 8-state
constituent encoders and one turbo coded internal interleaver. The coding rate of the turbo encoder is
1/2. The structure of the turbo encoder is shown in Figure 6. The PCCC transfer function is as follows.
G(D) = [1, g (D)/g (D)] (6)
1 0
2 3 3
where g (D) = 1+D +D , g (D) = 1+D+D .
0 1
When the input bits of the turbo encoder are encoded, the initial values of the shift registers of the
8-state constituent encoder shall all be zero.
For k = 0, 1, 2, …, B/2-1, the output value of the turbo encoder is expressed as follows.
c = x
4k 2k
c = z
4k+1 2k
c = x
4k+2 2k+1
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ISO/IEC 4005-4:2023(E)
c = z’ (7)
4k+3 2k+1
Output bits of the first and second 8-state constituent encoders for turbo encoder input bits b , b , b ,
0 1 2
b , …, b are z , z , z , z , …, z and z’ , z’ , z’ , z’ , …, z’ , and the output bits through the turbo code
3 B-1 0 1 2 3 B-1 0 1 2 3 B-1
internal interleaver that is described in Annex A are represented by b’ , b’ , b’ , b’ , …, b’ . These output
0 1 2 3 B-1
bits are used as inputs for the second 8-state constituent encoder.
Trellis termination is performed by taking tail bits from shift register feedback after all information
bits have been encoded. The generated tail bits are added after encoding of the information bits.
The first three tail bits are used for the first constituent encoder termination and not the second
constituent encoder. The remaining three tail bits are used for the termination of the second constituent
encoder and not the first constituent encoder.
The bits transmitted for trellis termination are determined as follows.
c = x , c = z , c
...

ISO/IEC FDIS 4005-4
ISO/IEC JTC 1/SC 6
Secretariat: KATS
Date: 2022-12-02
Telecommunications and information exchange between
Deleted: -
systems — Unmanned aircraft area network (UAAN) —
Deleted:
Part 4:
Deleted:
Physical and data link protocols for video communication
Télécommunications et échange d'information entre systèmes — Réseau de zone de drones (Unmanned
Deleted: ¶
Page Break
aircraft area network - UAAN) —
¶
ISO/IEC DIS 4005-4:2022(E)¶
Partie 4: Protocoles de liaison de données et physiques pour la communication vidéo
ISO/IEC JTC 1/SC 6/WG 1¶
Secretariat: KATS¶
Telecommunications and information exchange
between systems —
Deleted: (UAAN) — Part 4: Physical and data link
protocols for video communication
Deleted: ¶
FDIS stage
Deleted: ¶
Warning for DISs¶
This document is not an ISO International Standard. It is
distributed for review and comment. It is subject to
change without notice and may not be referred to as an
International Standard.¶
Recipients of this draft are invited to submit, with their
comments, notification of any relevant patent rights of
which they are aware and to provide supporting
documentation.¶
¶
© ISO 20XX¶
Deleted:
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ISO/IEC FDIS 4005-4:2022(E)
Deleted: DIS
© ISO/IEC 2022
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this
publication may be reproduced or utilized otherwise in any form or by any means, electronic or mechanical,
including photocopying, or posting on the internet or an intranet, without prior written permission. Permission can
be requested from either ISO at the address below or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: + 41 22 749 01 11
E-mail: [e-mail]
Deleted: Fax: [phone]¶
Website: www.iso.org
Email
Deleted: www.iso.org
Published in Switzerland
Deleted:
Deleted:
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ISO/IEC FDIS 4005-4:2022(E)
Deleted:

Deleted: DIS

Deleted: ¶
¶
Deleted:
Deleted:
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ISO/IEC FDIS 4005-4:2022(E)
Deleted: DIS
Foreword
ISO (the International Organization for Standardization) and IEC (the International Electrotechnical
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 technical
committees established by the respective organization to deal with particular fields of technical activity.
ISO and IEC technical committees collaborate in fields of mutual interest. Other international
organizations, governmental and non-governmental, in liaison with ISO and IEC, also take part in the
work.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the
different types of document should be noted. This document was drafted in accordance with the editorial
rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives or Deleted: www.iso.org/directives or
www.iec.ch/members_experts/refdocs
www.iec.ch/members_experts/refdocs).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO and IEC shall not be held responsible for identifying any or all such patent rights. Details
of any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www.iso.org/patents) or the IEC list of patent Deleted: www.iso.org/patents
declarations received (see https://patents.iec.ch).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to the World
Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see
www.iso.org/iso/foreword.html. In the IEC, see www.iec.ch/understanding-standards.
Deleted: www.iso.org/iso/foreword.html. In the IEC, see
www.iec.ch/understanding-standards
This document was prepared by Joint Technical Committee ISO/IEC JTC 1, Information technology,
Subcommittee SC 6, Telecommunications and information exchange between systems.
A list of all parts in the ISO/IEC 4005 series can be found on the ISO and IEC websites.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html and www.iec.ch/national-
Deleted: www.iso.org/members.html
committees.
Field Code Changed
Deleted:
Deleted:
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ISO/IEC FDIS 4005-4:2022(E)
Deleted:
Introduction
Deleted: DIS
Unmanned aircraft (UAs) operating at low altitudes will provide a variety of commercial services in the
near future. UAs that provide these services are distributed in the airspace. In level II, many people
operate their own UAs without the assignment of communication channels from a central control centre.
Deleted: center.
This document describes video communication, which is a wireless distributed communication. Video
communication allows UAs distributed over the airspace to transmit video without serious interference
to the relevant video receiver which is usually a controller. The channels used for video communication
have a multi-channel structure, which enables UA and video receiver pairs to independently use the
occupied communication link. A wireless distributed communication described by this document is
intended to be used in licensed frequency bands.
The ISO/IEC 4005 series consists of the following four parts:
Deleted: ISO/IEC 4005-1: To support various
ISO/IEC 4005-1: To support various services for UAs, it describes a wireless distributed
services for UAs, it describes a wireless distributed
communication model and the requirements that this model shall satisfy.
communication model and the requirements that
this model shall satisfy.¶
ISO/IEC 4005-2: It describes communication in which all units involved in UA operation can
ISO/IEC 4005-2: It describes communication in
broadcast or exchange information by sharing communication resources with each
which all units involved in UA operation can
other.
broadcast or exchange information by sharing
communication resources with each other.¶
ISO/IEC 4005-3: It describes the control communication for the controller to control the UA.
ISO/IEC 4005-3: It describes the control
communication for the controller to control the UA.¶
ISO/IEC 4005-4 (this document): It describes video communication for UAs to send video to a
ISO/IEC 4005-4 (this document): It describes video
controller.
communication for UAs to send video to a controller.¶

¶
The International Organization for Standardization (ISO) and International Electrotechnical Commission
(IEC) draw attention to the fact that it is claimed that compliance with this document may involve the use
of patents. Deleted:
ISO and IEC take no position concerning the evidence, validity and scope of these patent rights. Deleted:
The holders of these patent rights have assured ISO and IEC that they are willing to negotiate licences
under reasonable and non-discriminatory terms and conditions with applicants throughout the world. In
this respect, the statements of the holders of these patent rights are registered with ISO and IEC.
Information may be obtained from the patent database available at www.iso.org/patents.
Deleted: www.iso.org/patents.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights other than those in the patent database. ISO and IEC shall not be held responsible for
identifying any or all such patent rights.
Deleted: ¶
Deleted:
Deleted:
© ISO/IEC 2022 – All rights reserved v

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ISO/IEC FDIS 4005-4:2022(E)
Telecommunications and information exchange between
Deleted:
systems — Unmanned aircraft area network (UAAN) —
Deleted: —
Deleted:
Part 4:
Deleted:
Physical and data link protocols for video communication
1 Scope
This document specifies communication protocols for the physical and data link layer of video
communication, which is a wireless distributed communication network for level II unit-related Deleted: units
unmanned aircraft (UAs).
Deleted: with
This document describes video communication, which is one-to-one communication that transmits video Deleted: in level II.
from a UA to a video receiver. For the specific use of video communication, video can be transmitted from
a UA to multiple receivers.
2 Normative references
Deleted: ISO 21384-4: Unmanned aircraft systems — Part
The following documents are referred to in the text in such a way that some or all of their content
4: UAS vocabulary¶
constitutes requirements of this document. For dated references, only the edition cited applies. For
Deleted:
undated references, the latest edition of the referenced document (including any amendments) applies.
Deleted: :
ISO/IEC 4005-1, Telecommunications and information exchange between systems — Unmanned aircraft
Deleted:
area network (UAAN) — Part 1: Communication model and requirements
Deleted: :
ISO/IEC 4005-2, Telecommunications and information exchange between systems — Unmanned aircraft Deleted:
area network (UAAN) — Part 2: Physical and data link protocols for shared communication
Deleted: :
Deleted:
ISO/IEC 4005-3, Telecommunications and information exchange between systems — Unmanned aircraft
Deleted:
area network (UAAN) — Part 3: Physical and data link protocols for control communication
Deleted: —
ISO 21384-4, Unmanned aircraft systems — Part 4: Vocabulary
Deleted: https://www.iso.org/obp
Deleted: —
3 Terms and definitions
Deleted: https://www.electropedia.org/
For the purposes of this document, the terms and definitions defined in ISO/IEC 4005-1, ISO/IEC 4005-
Deleted: ¶
2, ISO/IEC 4005-3, ISO 21384-4 and the following apply.
Deleted: CC Control Communication¶
ISO and IEC maintain terminology databases for use in standardization at the following addresses: CB Coding Block¶
CRC Cyclic Redundancy Check¶
— ISO Online browsing platform: available at https://www.iso.org/obp
CSCH Control Subchannel¶
DL Data Link¶
DLL Data Link Layer¶
— IEC Electropedia: available at https://www.electropedia.org/
DQPSK Differential Quadrature Phase Shift Keying ¶
DS Dedicated Slot¶
4 Abbreviated terms
FN Frame Number¶
GF Galois Field¶
PCCC Parallel Concatenated Convolutional Code¶
CC Control Communication
PB Parsing Block¶
PH Parsing Header¶
CB Coding Block
PKH Packet Header¶
CRC Cyclic Redundancy Check
PN Pseudo Noise¶
SA Source Address¶
CSCH Control Subchannel
SC Shared Communication¶
SRRC Square Root Raised Cosine¶
DL Data Link
TSB Tone Slot Block¶
UTC Coordinated Universal Time¶
DLL Data Link Layer
VC Video Communication¶
DQPSK Differential Quadrature Phase Shift Keying VSCH Video Subchannel¶
¶
DS Dedicated Slot
Deleted:
FN Frame Number
Deleted:
© ISO/IEC 2022 – All rights reserved 1

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ISO/IEC FDIS 4005-4:2022(E)
GF Galois Field
PCCC Parallel Concatenated Convolutional Code
PB Parsing Block
PH Parsing Header
PKH Packet Header
PN Pseudo Noise
SA Source Address
SC Shared Communication
SRRC Square Root Raised Cosine
TSB Tone Slot Block
UTC Coordinated Universal Time
VC Video Communication
VSCH Video Subchannel
5 Physical layer
5.1 Channel and frame structure for data channel
Deleted:
Deleted: Figure 1.
5.1.1 The number of data channels and bandwidth
Deleted:
The number of data channels is L. L is greater than or equal to one. The bandwidth of one data channel is
5 MHz as shown in Figure 1. The L is determined in the upper layer.
5MHz 5MHz
(#0) (#1)

Deleted: 1
Figure 1 — Data channels in frequency region
Deleted: second
Deleted:
5.1.2 Frame structure
Deleted:
Deleted: Figure 2.
The frame length of the data channel is 1 sec and consists of 250 slots. The one slot time Ts is 4 ms. A data
Deleted: minute
slot block has 2 slots. Therefore, there are 125 data slot blocks in one frame, and the data slot block is
8 ms in length as shown in Figure 2. The frame number, FN changes from 0 to 59 in a 1 min interval, and
Deleted:
has the same value as the second of the current time. a
b
#0 #1 #2 #3 #4 #5 #6 #7
c
Key¶

a
1 frame, Tf = 1 second = 250 Ts¶
b
  1 slot, Ts = 4 ms¶
c
1 slot block, T = 8 ms = 2 T ¶
sb s
a
1 frame, Tf = 1 second = 250 Ts.
Deleted:
b
1 slot, Ts = 4 ms.
Deleted:
2 © ISO/IEC 2022 – All rights reserved

---------------------- Page: 7 ----------------------
ISO/IEC FDIS 4005-4:2022(E)
c
1 slot block, Tsb = 8 ms = 2 Ts.
Deleted: 2
Deleted: Figure 3.
Figure 2 — Data channel frame structure
Deleted:
a
5.1.3 Slot transmit time mask
The transmission time mask of a slot is as shown in Figure 3.
b
T T
0 1
Deleted: T 0 μs¶
0
T1, T2, T3, T4 symbol offset from T0¶
a
4 ms¶

b
modulated signal¶
Key
Deleted: 3
T0 0 μs
Deleted: Where
T , T , T , T symbol offset from T
1 2 3 4 0
Deleted: second
a
4 ms.
Deleted: .
b
Modulated signal.
Deleted: Where
Figure 3 — The transmission time mask of a slot Deleted:
Deleted:
T , T , T , T are symbol offsets from T and symbol time is 1/2688000 sec. Each value is as follows: T is
1 2 3 4 0 1
Deleted:
8, T is 10380, T is 10388, T is 10752.
2 3 4
Deleted:
T is 0 μs as the start time of the slot and the power amplifier is gated on and unmodulated fine signals
0 0 2 4
begin to be transmitted. T is an offset at which modulation signal transmission starts. T is an offset at
1 2
0
which the transmission of the modulated signal ends. T is an offset at which the power amplifier is gated
3 10
off, and transmission of unmodulated fine signals is stopped. The transmit power of T to T , T to T shall
0 1 2 3
20
be at least 50 dB less than the modulation signal transmit power.
30
40
5.1.4 Sub channels
50
60
70
80
90
100
110
a
120
130
140
150
160
170
180
190
200
210
220
230
240
b c
Key¶
a
V ¶
x
...

Deleted:

Deleted:
© ISO/IEC 2022 – All rights reserved 3

---------------------- Page: 8 ----------------------
ISO/IEC FDIS 4005-4:2022(E)
a
Vx.
b
Vx,0.
c
Vx,1.
d
Vx,8.
e
Vx,9.
Figure 4 — Sub channel structure of video communication in even frame
Deleted: 4
One data channel consists of 10 subchannels as shown in Figure 4. Subchannel y of video channel x is Deleted: Figure 4.
composed of the following slot set.
Vx,y = Sx,z, Sx,z+10, Sx,z+20, …, Sx,z+240 Deleted:
𝑦𝑦,     𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒 𝑓𝑓𝑓𝑓𝑓𝑓𝑓𝑓𝑒𝑒
y, evenframe
𝑧𝑧 = (1)
Deleted: z=
𝑦𝑦 + 1−⌊(𝑦𝑦mod2)/2⌋ × 2, 𝑜𝑜𝑜𝑜𝑜𝑜 𝑓𝑓𝑓𝑓𝑓𝑓𝑓𝑓𝑒𝑒
y+−1 (y mod2) / 2× 2, oddframe
 
(1)¶
where
 y is subchannel number, y=0, 1, …, 9; Deleted: ,
 S is slot z of video channel x.
x,z Deleted: ;
The subchannel consists of 25 slots, the i-th slot resource of the subchannel y of the channel x is indicated
by SRx,y,i, and the subchannel y of frequency channel x is indicated by Vx,y. Therefore, Vx,y is as follows. Deleted:
Vx,y = SRx,y,0, SRx,y,1, …, SRx,y,24 (2) Deleted: (2)
where SR  is i-th slot resource of subchannel y of channel x, i=0, …, 24.
x,y,i Deleted: where ¶
...
All slots of video channel are downlink.
5.1.5 Dedicated subchannels
The upper layer can predetermine one or several subchannels as dedicated subchannels. In this case, the
tone subslot set mapped with the dedicated subchannel is not used as a competition tone and can be used Deleted: ,
for other purposes.
Dedicated subchannel information is received from an upper layer through
UPtoDL.InfoDedicatedChannel.
5.2 Channel and frame structure for tone channel
5.2.1 General
The tone channel of video communication means a competitive tone channel. The tone channel used for
video communication resource allocation and the tone channel used for control communication resource
allocation are the same channel (see ISO/IEC 4005-3).
5.2.2 Slot transmit power
The maximum transmission power PmaxTCH of the tone slot mapped to the video subchannel (VSCH) is
received as UPtoDL.InfoPowerParamVCH from the upper layer. The power of the tone subslot signal is
determined by adding the PTX_VCHTCH_differ value to the transmission power of the mapped VSCH.
Deleted: video subchannel
5.3 Encoding procedure
The encoding follows the following procedure. CRC encoding, turbo coding, rate matching, interleaving,
modulation mapping, burst mapping, and pulse mapping are performed in this order as shown in
Figure 5.
Deleted: Figure 5.
Deleted:
Deleted:
4 © ISO/IEC 2022 – All rights reserved

---------------------- Page: 9 ----------------------
ISO/IEC FDIS 4005-4:2022(E)
a b
CRC Turbo
encoding encoding
h
Pulse
mapping
Deleted:

Figure 5 — Encoding procedure Deleted: 5
The number of symbols according to each encoding stage is shown in Table 1, where the encoding input Deleted: Table 1,
consists of two code blocks, CB0 and CB1 as shown in Figure 14. Each code block undergoes CRC
Deleted: Figure 14
encoding, turbo coding, rate matching, interleaving, and modulation mapping processes, respectively.
The length of each code block in these processes is 4094, 4928, 9868, 9856, 9856, and 4928. The two
code blocks are merged into one burst during burst mapping.
Table 1 — Number of symbols at each encoding stage
Deleted: ¶
Deleted: 1
Stage Number of symbols
a 4904 × 2 (binary) Deleted: 
b 4928 × 2 (binary) Deleted: 
c 9868 × 2 (binary)
Deleted: 
Deleted: )
d 9856 × 2 (binary)
Deleted: 
e 9856 × 2 (binary)
Deleted: 
f 4928 × 2 (complex)
Deleted: 
g 10364 (complex)
h 10372 × OS (complex)
5.3.1 CRC encoding
Deleted: ¶
The input bits are defined as a0, a1, a2, a3, …, aA-1 and parity bits as p0, p1, p2, p3, …, p23 where A represents
the number of input sequences. Parity bits are generated through CRC generation polynomial as follows.
24 22 6 5
g (D) = D + D + D + D + D + 1 (3) Deleted: (3)
CRC
The encoding performed through the cyclic generator polynomials has a systematic form as follows. The
resulting polynomial has zero remainder when it is divided by g (D) on GF(2).
CRC
A+23 A+22 24 23 22 1
a D + a D + … + a D + p D + p D + … + p D + p (4) Deleted: (4)
0 1 A-1 0 1 22 23
After CRC insertion, bits are represented by b0, b1, b2, b3, …, bB-1 (where B = A + 24), and the relationship
between a and b is as follows.
k k
𝑓𝑓 , 𝑓𝑓𝑜𝑜𝑓𝑓 𝑘𝑘 = 0,1,2,⋯ ,𝐴𝐴− 1
𝑘𝑘
a , fork 0,1,2,,A−1
k
𝑏𝑏 = (5)
𝑘𝑘
Deleted: b =
𝑃𝑃 , 𝑓𝑓𝑜𝑜𝑓𝑓 𝑘𝑘 =𝐴𝐴,𝐴𝐴 + 1,𝐴𝐴 + 2,⋯ ,𝐴𝐴 + 23
k
𝑘𝑘−𝐴𝐴
P , fork= A,A++1,2A ,,2A+
kA−
(5)¶
5.3.2 Turbo encoding
The turbo encoder consists of Parallel Concatenated Convolutional Code (PCCC) with two 8-state
constituent encoders and one turbo coded internal interleaver. The coding rate of the turbo encoder is
1/2. The structure of the turbo encoder is shown in Figure 6. The PCCC transfer function is as follows. Deleted: Figure 6.
G(D) = [1, g (D)/g (D)] (6) Deleted: (6)
1 0
2 3 3
where g0(D) = 1+D +D , g1(D) = 1+D+D .
Deleted:
Deleted:
© ISO/IEC 2022 – All rights reserved 5
=

---------------------- Page: 10 ----------------------
ISO/IEC FDIS 4005-4:2022(E)
When the input bits of the turbo encoder are encoded, the initial values of the shift registers of the 8-state
constituent encoder shall all be zero.
For k = 0, 1, 2, …, B/2-1, the output value of the turbo encoder is expressed as follows.
c = x
4k 2k
c = z
4k+1 2k
c = x
4k+2 2k+1
c = z’ (7) Deleted: (7)
4k+3 2k+1
Output bits of the first and second 8-state constituent encoders for turbo encoder input bits b0, b1, b2, b3,
…, b are z , z , z , z , …, z and z’ , z’ , z’ , z’ , …, z’ , and the output bits through the turbo code internal
B-1 0 1 2 3 B-1 0 1 2 3 B-1
interleaver that is described in Annex A are represented by b’0, b’1, b’2, b’3, …, b’B-1. These output bits are Deleted: Annex A
used as inputs for the second 8-state constituent encoder.
Trellis termination is performed by taking tail bits from shift register feedback after all information bits
have been encoded. The generated tail bits are added after encoding of the information bits.
The first three tail bits are used for the first constituent encoder termination and not the second
constituent encoder. The remaining three tail bits are used for the termination of the second constituent
encoder and not the first constituent encoder.
Deleted: (8)
The bits transmitted for trellis termination are determined as follows.
Deleted:
c = x , c = z , c = x’ , c = z’
2B B 2B+3 B+1 2B+6 B 2B+9 B+1
c = z , c = x , c = z’ , c = x’
2B+1 B 2B+4 B+2 2B+7 B 2B+10 B+2
c2B+2 = xB+1, c2B+5 = zB+2, c2B+8 = x’B+1, c2B+11 = z’B+2 (8)
b
k
D D
2
3
1
b'
k
D D
Deleted: 1 turbo code internal interleaver¶
2 first constituent encoder¶
3 second constituent encoder¶
D register¶
bk a k-th bit of turbo encoder input¶
b’k a k-th bit of turbo code internal interleaver
Key
output¶
1 turbo code internal interleaver x a k-th systematic bit of turbo encoder output¶
k
zk a k-th bit of first constituent encoder output¶
2 first constituent encoder
x’k a k-th bit of second constituent encoder output
3 second constituent encoder
for trellis termination¶
D register z’ a k-th bit of second constituent encoder output¶
k
b a k-th bit of turbo encoder input
k
Deleted:
b’k a k-th bit of turbo code internal interleaver output
Deleted:
6 © ISO/IEC 2022 – All rights reserved

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ISO/IEC FDIS 4005-4:2022(E)
xk a k-th systematic bit of turbo encoder output
z a k-th bit of first constituent encoder output
k
x’k a k-th bit of second constituent encoder output for trellis termination
z’k a k-th bit of second constituent encoder output
Figure 6 — Turbo encoder structure Deleted: 6
Input bit sequence of turbo code internal interleave, b , b , b , b , …, b and output bit sequence generated
0 1 2 3 B-1
from turbo code internal interleaver, b’ , b’ , b’ , b’ , …, b’ have the following relationship.
0 1 2 3 B-1
b’ = b (9) Deleted: (9)
i j
where the mapping between the output bit index i and the input bit index j shall follow Table A.1 of Deleted: Table A.1
Annex A where j and i are as follows, and row and column numbers start at zero.
Deleted: Annex A
j = (number shown in table) − 1
Deleted: -
i = (row number in table) × 16+(column number in table) (10) Deleted: )
Deleted: (10)
5.3.3 Rate matching
Deleted: Matching
Rate matching outputs d0, d1, d2, d3, …, dD-1 by puncturing the input bits c0, c1, c2, c3, …, cC-1. The puncturing
bit numbers are as follows.
— 821, 1643, 2461, 3283, 4101, 4923, 5741, 6563, 7381, 8203, 9021, 9843
5.3.4 Interleaving
The interleaver uses block interleaving with 77 rows and 128 columns.
em = dn
m = (n x 77) %9856 + ⎿n/128⏌ (11) Deleted: 
Deleted: )%
where ⎿x⏌ means the largest integer among integers less than or equal to x and 0 ≤ n ≤ 9855.
Deleted: ⌊
5.3.5 Modulation mapping
Deleted: ⌋ (11)
Deleted: ⌊
Modulation mapping generates a complex symbol f from the input bit e , 0 ≤ n ≤ 9855, 0 ≤ m ≤ 4927. Two
n m
input bits are mapped to one complex number as shown in Table 2. Deleted: ⌋
Table 2 — Modulation mapping Deleted: ≤
e2ne2n+1 00 01 10 11 Deleted: ≤
f exp(j/4π) exp(j·7/4π) exp(j·3/4π) exp(j·5/4π)
n Deleted: ≤
5.3.6 Burst mapping
Deleted: ≤
Output complex symbols g , g , …, g are generated from f , f , …, f of CB0 and f , f , …, f of CB1. Deleted: ≤
0 1 4927 0 1 4927 0 1 4927
𝑛𝑛
𝑔𝑔 = 𝑐𝑐(𝑘𝑘) (12) Deleted: ≤
�
𝑛𝑛
𝑘𝑘=0
Deleted: Table 2.
where c(n) is shown in Table 3.
Deleted: 2
Table 3 — c(n)
Deleted: ¶
n
Number of
Deleted: g = ck() (12)¶
∏
n c(n)
n k=0
symbols
Deleted: Table 3
0, 1 TSS(n) 2
Deleted: 3
2, …, 37 PTS1(n-2) 36
38, …, 767 fn-38 of CB0 730
Deleted:
768, …, 803 PTS1(n-768) 36
Deleted:
© ISO/IEC 2022 – All rights reserved 7

---------------------- Page: 12 ----------------------
ISO/IEC FDIS 4005-4:2022(E)
Number of
n c(n)
symbols
804, …, 1533 fn-74 of CB0 730
1534, …, 1569 PTS1(n-1534) 36
1570, …, 2299 fn-110 of CB0 730
Deleted:
2300, …, 2335 PTS1(n-2300) 36
2336, …, 3065 f of CB0 730
n-146
3066, …, 3101 PTS1(n-3066) 36
3102, …, 3831 f of CB0 730
n-182
3832, …, 3867 PTS1(n-3832) 36
3868, …, 4597 fn-218 of CB0 730
4598, …, 4633 PTS1(n-4598) 36
4634, …, 5181 fn-254 of CB0 548
5182, … 5363 f of CB1 182
n-5182
5364, …,5399 PTS1(n-5364) 36
Deleted:
5400, …, 6129 fn-5218 of CB1 730
6130, …, 6165 PTS1(n-6130) 36
6166, …, 6895 fn-5254 of CB1 730
6896, …, 6931 PTS1(n-6896) 36
6932, …, 7661 f of CB1 730
n-5290
7662, …, 7697 PTS1(n-7662) 36
7698, …, 8427 f of CB1 730
n-5326
8428, …, 8463 PTS1(n-8428) 36
8464, …, 9193 fn-5362 of CB1 730
9194, …, 9229 PTS1(n-9194) 36
9230, …, 9959 fn-5398 of CB1 730
9960, …, 9995 PTS1(n-9960) 36
9996, …, 10361 fn-5434 of CB1 366
10362, 10363 TSS(n-10362) 2
where TSS(n) and PTS1(n) are shown in Table 4 and Table 5 respectively.
Deleted: ¶
Deleted: Table 4
Table 4 — TSS(n)
Deleted: Table 5
TSS(0) TSS(1)
Deleted: 4
exp(j·3/4π) exp(j·7/4π)
Table 5 — PTS1(n)
Deleted: ¶
Table 5 — 𝐏𝐏𝐏𝐏𝐏𝐏𝐏𝐏(𝐧𝐧)¶
n PTS1(n) n PTS1(n) n PTS1(n)
0 exp(j·5/4π) 12 exp(j·5/4π) 24 exp(j·7/4π)
1 exp(j·7/4π) 13 exp(j/4π) 25 exp(j·5/4π)
2 exp(j·7/4π) 14 exp(j/4π) 26 exp(j·7/4π)
3 exp(j·5/4π) 15 exp(j·5/4π) 27 exp(j/4π)
4 exp(j/4π) 16 exp(j·7/4π) 28 exp(j·5/4π)
Deleted:
Deleted:
8 © ISO/IEC 2022 – All rights reserved

---------------------- Page: 13 ----------------------
ISO/IEC FDIS 4005-4:2022(E)
n PTS1(n) n PTS1(n) n PTS1(n)
5 exp(j/4π) 17 exp(j/4π) 29 exp(j·3/4π)
6 exp(j·3/4π) 18 exp(j·5/4π) 30 exp(j·3/4π)
7 exp(j·5/4π) 19 exp(j·3/4π) 31 exp(j/4π)
8 exp(j·3/4π) 20 exp(j·7/4π) 32 exp(j/4π)
9 exp(j/4π) 21 exp(j/4π) 33 exp(j·5/4π)
10 exp(j·5/4π) 22 exp(j/4π) 34 exp(j·3/4π)
Deleted: ¶
11 exp(j·5/4π) 23 exp(j·3/4π) 35 exp(j·7/4π)
Deleted: . Where
5.3.7 Pulse mapping
Deleted: ≤
Deleted: <
The complex symbol g is converted into a complex signal h , where the oversampling ratio of the filter
m n
is OS times and depends on implementation. For 0 ≤ n < 10372 × OS, the complex signal is defined as Deleted: 
follows.
nT 
n
10363
s
Deleted: h w p (−−m 4)Tg
10363  ∑ 
n m=0 s
 
𝑛𝑛𝑇𝑇 𝑛𝑛
𝑠𝑠 OS OS

 
ℎ =𝑤𝑤( ) 𝑝𝑝(( −𝑓𝑓− 4)𝑇𝑇 )𝑔𝑔 (13)
�
𝑛𝑛 𝑠𝑠 𝑚𝑚
𝑂𝑂𝑂𝑂 𝑂𝑂𝑂𝑂
𝑚𝑚=0 (13)¶
sin (1
  (
where symbol duration T is the 1/2688000 second and pulse shape p(t) is defined as SRRC function of (1+α)πt
s
cos +
 
 
roll-off factor 0,35 as follows.
T 4
1
 s 
Deleted: pt()= 
(1+𝛼𝛼)𝜋𝜋𝜋𝜋 sin((1−𝛼𝛼)𝜋𝜋𝜋𝜋/𝑇𝑇 )
𝑠𝑠
(1−α)π
1− (4αtT/ )
cos( )+
1 s
𝑇𝑇 4𝛼𝛼𝜋𝜋/𝑇𝑇 1+
𝑠𝑠 𝑠𝑠
𝑝𝑝(𝑡𝑡) = · (14)
4α
(1−𝛼𝛼)𝜋𝜋 2
1−(4𝛼𝛼𝛼𝛼/𝑇𝑇 )
1+ 𝑠𝑠
4𝛼𝛼
(14)¶
(1/ 2)(1− cos(πtT2 )),
The window function w(t) is defined as follows.
s
1, 2T ≤
(1/2)(1− cos(𝜋𝜋𝑡𝑡 2𝑇𝑇 )), 0≤𝑡𝑡 < 2𝑇𝑇
⁄ s
𝑠𝑠 𝑠𝑠
1,   2𝑇𝑇 ≤𝑡𝑡 < 10370𝑇𝑇 Deleted: wt()=

𝑠𝑠 𝑠𝑠
π
𝜋𝜋 (1/ 2)(1−−cos (tT10372 ) ),
𝑤𝑤(𝑡𝑡) = (15) 
s

(1/2)(1− cos( (𝑡𝑡− 10372𝑇𝑇 ))), 10370𝑇𝑇 ≤𝑡𝑡 < 10372𝑇𝑇
2T
𝑠𝑠 𝑠𝑠 𝑠𝑠
2𝑇𝑇 s
𝑠𝑠
0,        𝑜𝑜𝑡𝑡ℎ𝑒𝑒𝑓𝑓𝑤𝑤𝑒𝑒𝑒𝑒𝑒𝑒 0,
(15)¶
The modulated signal is shown in Figure 7. Timing of modulated signal transmission is as described in
¶
5.1.3, i.e. the modulated signals are transmitted in the time intervals of T to T as shown in Figure 3.
1 2
Deleted: Figure 7.
Deleted: 5.1.3, i.e.
Deleted: Figure 3
Deleted: ¶
1 2 3 4 5 6

Key
1 filter ripple (4 symbols)
a
2 TSS (2 symbols)
3 PTS1 (36 symbols)
Deleted: 1 filter ripple (4 symbols)¶
4 data (730 symbols)
2 TSS (2 symbols)¶
5 PTS1 (36 symbols) 3 PTS1 (36 symbols)¶
4 data (730 symbols)¶
6 data (730 symbols)
5 PTS1 (36 symbols)¶
7 PTS1 (36 symbols)
6 data (730 symbols)¶
8 data (730 symbols) 7 PTS1 (36 symbols)¶
8 data (730 symbols)¶
9 PTS1 (36 symbols)
9 PTS1 (36 symbols)¶
10 data (336 symbols)
10 data (336 symbols)¶
11 TSS (2 symbols) 11 TSS (2 symbols)¶
12 filter ripple (4 symbols)¶
12 filter ripple (4 symbols)
a
modulated signal (10372 DQPSK symbol)¶
a
Modulated signal (10372 DQPSK symbol).
Deleted:
Deleted:
© ISO/IEC 2022 – All rights reserved 9
=

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ISO/IEC FDIS 4005-4:2022(E)
Figure 7 — Modulated signal structure Deleted: 7
5.4 Physical layer procedure
5.4.1 Synchronization
All messages shall be transmitted based on UTC time. All times are measured based on UTC. Deleted:
The synchronization mode of the unit includes 'A sync', 'B sync' and 'C sync'.
— A sync is synchronization obtained from UTC.
— B sync is secondary synchronization acquired from the synchronization signal of the A sync unit.
— C sync is sync status within 20 seconds after sudden loss of sync in A or B sync mode.
A sync unit shall know the date, hour, minute, second, slot number.
The time error of A sync shall be within ±0,4 μs. The time error of B sync shall be within ±4 μs. The time Deleted:
error of C sync shall be within ±5 μs.
Deleted:
The frequency error of A sync shall be within ±0,1 ppm. The frequency error of the B sync shall be within
Deleted:
±0,2 ppm. The frequency error of the C sync shall be within ±0,3 ppm.
Deleted:
5.4.2 Subchannel power
Deleted:
Deleted:
The maximum power PmaxVCH of the VSCH is received as UPtoDL.InfoPowerParamVCH from an upper
Deleted: video subchannel
layer. The maximum transmission power and minimum transmiss
...

FINAL
INTERNATIONAL ISO/IEC
DRAFT
STANDARD FDIS
4005-4
ISO/IEC JTC 1/SC 6
Telecommunications and information
Secretariat: KATS
exchange between systems —
Voting begins on:
2022-12-16 Unmanned aircraft area network
(UAAN) —
Voting terminates on:
2023-02-10
Part 4:
Physical and data link protocols for
video communication
Télécommunications et échange d'information entre systèmes —
Réseau de zone de drones (Unmanned aircraft area network -
UAAN) —
Partie 4: Protocoles de liaison de données et physiques pour la
communication vidéo
RECIPIENTS OF THIS DRAFT ARE INVITED TO
SUBMIT, WITH THEIR COMMENTS, NOTIFICATION
OF ANY RELEVANT PATENT RIGHTS OF WHICH
THEY ARE AWARE AND TO PROVIDE SUPPOR TING
DOCUMENTATION.
IN ADDITION TO THEIR EVALUATION AS
Reference number
BEING ACCEPTABLE FOR INDUSTRIAL, TECHNO-
ISO/IEC FDIS 4005-4:2022(E)
LOGICAL, COMMERCIAL AND USER PURPOSES,
DRAFT INTERNATIONAL STANDARDS MAY ON
OCCASION HAVE TO BE CONSIDERED IN THE
LIGHT OF THEIR POTENTIAL TO BECOME STAN-
DARDS TO WHICH REFERENCE MAY BE MADE IN
NATIONAL REGULATIONS. © ISO/IEC 2022

---------------------- Page: 1 ----------------------
ISO/IEC FDIS 4005-4:2022(E)
FINAL
INTERNATIONAL ISO/IEC
DRAFT
STANDARD FDIS
4005-4
ISO/IEC JTC 1/SC 6
Telecommunications and information
Secretariat: KATS
exchange between systems —
Voting begins on:
Unmanned aircraft area network
(UAAN) —
Voting terminates on:
Part 4:
Physical and data link protocols for
video communication
Télécommunications et échange d'information entre systèmes —
Réseau de zone de drones (Unmanned aircraft area network -
UAAN) —
Partie 4: Protocoles de liaison de données et physiques pour la
communication vidéo
COPYRIGHT PROTECTED DOCUMENT
© ISO/IEC 2022
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
or ISO’s member body in the country of the requester.
RECIPIENTS OF THIS DRAFT ARE INVITED TO
ISO copyright office
SUBMIT, WITH THEIR COMMENTS, NOTIFICATION
OF ANY RELEVANT PATENT RIGHTS OF WHICH
CP 401 • Ch. de Blandonnet 8
THEY ARE AWARE AND TO PROVIDE SUPPOR TING
CH-1214 Vernier, Geneva
DOCUMENTATION.
Phone: [phone]
IN ADDITION TO THEIR EVALUATION AS
Reference number
Email: [e-mail]
BEING ACCEPTABLE FOR INDUSTRIAL, TECHNO­
ISO/IEC FDIS 4005­4:2022(E)
Website: www.iso.org
LOGICAL, COMMERCIAL AND USER PURPOSES,
DRAFT INTERNATIONAL STANDARDS MAY ON
Published in Switzerland
OCCASION HAVE TO BE CONSIDERED IN THE
LIGHT OF THEIR POTENTIAL TO BECOME STAN­
DARDS TO WHICH REFERENCE MAY BE MADE IN
ii
  © ISO/IEC 2022 – All rights reserved
NATIONAL REGULATIONS. © ISO/IEC 2022

---------------------- Page: 2 ----------------------
ISO/IEC FDIS 4005-4:2022(E)
Contents Page
Foreword .v
Introduction . vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Abbreviated terms . 1
5 Physical layer . 2
5.1 Channel and frame structure for data channel . 2
5.1.1 The number of data channels and bandwidth . 2
5.1.2 Frame structure . 3
5.1.3 Slot transmit time mask . . 3
5.1.4 Sub channels . 4
5.1.5 Dedicated subchannels . 5
5.2 Channel and frame structure for tone channel . 5
5.2.1 General . 5
5.2.2 Slot transmit power . 5
5.3 Encoding procedure . 5
5.3.1 CRC encoding . 6
5.3.2 Turbo encoding . 6
5.3.3 Rate matching . 9
5.3.4 Interleaving . 9
5.3.5 Modulation mapping . 9
5.3.6 Burst mapping . 9
5.3.7 Pulse mapping . 11
5.4 Physical layer procedure .12
5.4.1 Synchronization .12
5.4.2 Subchannel power .12
5.4.3 Measurements .12
5.4.4 Coexistence operation .12
6 Data link layer .13
6.1 General .13
6.2 Channel mapping and measurements. 14
6.2.1 General . 14
6.2.2 Mapping of communication resources and subslot sets. 14
6.2.3 Interference power calculation . 15
6.2.4 Subchannel map . 16
6.3 Subchannel negotiation for allocation . 16
6.3.1 General . 16
6.3.2 Subchannel negotiation using shared channel . 20
6.3.3 Subchannel negotiation using dedicated slot . 23
6.3.4 Subchannel negotiation using CSCH . 24
6.4 Subchannel allocation and generated link confirmation . 25
6.4.1 General . 25
6.4.2 Subchannel resource allocation competition . 26
6.4.3 Generated link confirmation . 27
6.4.4 Broadcasting video subchannel (VSCH) information being allocated or
occupied .28
6.5 Subchannel occupation and collision management .29
6.5.1 General .29
6.5.2 Power control in occupation stage .29
6.5.3 Subchannel occupation and return method.30
6.5.4 Collision tone transmission and collision management .30
iii
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ISO/IEC FDIS 4005-4:2022(E)
6.5.5 Parsing block for video channel .30
6.6 Reallocation . . 30
6.6.1 General .30
6.6.2 Reallocation decision . 31
6.6.3 Subchannel reallocation procedure . 32
6.7 Data exchange . 33
6.7.1 General . 33
6.7.2 Data packet format .34
6.8 Synchronization . 35
6.9 Data link layer security . 35
6.10 Interface with upper layer. 37
6.10.1 General . 37
6.10.2 Initialization interface. 37
6.10.3 Dynamic interface . 42
6.11 Interface with other communication layer .46
6.11.1 General .46
6.11.2 Interface with SC .46
6.11.3 Interface with CC . 47
Annex A (normative) Turbo internal interleaver table .50
iv
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ISO/IEC FDIS 4005-4:2022(E)
Foreword
ISO (the International Organization for Standardization) and IEC (the International Electrotechnical
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 technical
committees established by the respective organization to deal with particular fields of technical
activity. ISO and IEC technical committees collaborate in fields of mutual interest. Other international
organizations, governmental and non­governmental, in liaison with ISO and IEC, also take part in the
work.
The procedures used to develop this document and those intended for its further maintenance
are described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria
needed for the different types of document should be noted. This document was drafted in
accordance with the editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives or
www.iec.ch/members_experts/refdocs).
Attention is drawn to the possibility that some of the elements of this document may be the subject
of patent rights. ISO and IEC shall not be held responsible for identifying any or all such patent
rights. Details of any patent rights identified during the development of the document will be in the
Introduction and/or on the ISO list of patent declarations received (see www.iso.org/patents) or the IEC
list of patent declarations received (see https://patents.iec.ch).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to
the World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see
www.iso.org/iso/foreword.html. In the IEC, see www.iec.ch/understanding­standards.
This document was prepared by Joint Technical Committee ISO/IEC JTC 1, Information technology,
Subcommittee SC 6, Telecommunications and information exchange between systems.
A list of all parts in the ISO/IEC 4005 series can be found on the ISO and IEC websites.
Any feedback or questions on this document should be directed to the user’s national standards
body. A complete listing of these bodies can be found at www.iso.org/members.html and
www.iec.ch/national­committees.
v
© ISO/IEC 2022 – All rights reserved

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ISO/IEC FDIS 4005-4:2022(E)
Introduction
Unmanned aircraft (UAs) operating at low altitudes will provide a variety of commercial services in
the near future. UAs that provide these services are distributed in the airspace. In level II, many people
operate their own UAs without the assignment of communication channels from a central control
centre.
This document describes video communication, which is a wireless distributed communication. Video
communication allows UAs distributed over the airspace to transmit video without serious interference
to the relevant video receiver which is usually a controller. The channels used for video communication
have a multi-channel structure, which enables UA and video receiver pairs to independently use the
occupied communication link. A wireless distributed communication described by this document is
intended to be used in licensed frequency bands.
The ISO/IEC 4005 series consists of the following four parts:
ISO/IEC 4005­1: To support various services for UAs, it describes a wireless distributed communication
model and the requirements that this model shall satisfy.
ISO/IEC 4005­2: It describes communication in which all units involved in UA operation can broadcast
or exchange information by sharing communication resources with each other.
ISO/IEC 4005­3: It describes the control communication for the controller to control the UA.
ISO/IEC 4005­4 (this document): It describes video communication for UAs to send video to a controller.

The International Organization for Standardization (ISO) and International Electrotechnical
Commission (IEC) draw attention to the fact that it is claimed that compliance with this document may
involve the use of patents.
ISO and IEC take no position concerning the evidence, validity and scope of these patent rights.
The holders of these patent rights have assured ISO and IEC that they are willing to negotiate licences
under reasonable and non-discriminatory terms and conditions with applicants throughout the world.
In this respect, the statements of the holders of these patent rights are registered with ISO and IEC.
Information may be obtained from the patent database available at www.iso.org/patents.
Attention is drawn to the possibility that some of the elements of this document may be the subject
of patent rights other than those in the patent database. ISO and IEC shall not be held responsible for
identifying any or all such patent rights.
vi
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FINAL DRAFT INTERNATIONAL STANDARD ISO/IEC FDIS 4005-4:2022(E)
Telecommunications and information exchange between
systems — Unmanned aircraft area network (UAAN) —
Part 4:
Physical and data link protocols for video communication
1 Scope
This document specifies communication protocols for the physical and data link layer of video
communication, which is a wireless distributed communication network for level II unit­related
unmanned aircraft (UAs).
This document describes video communication, which is one­to­one communication that transmits
video from a UA to a video receiver. For the specific use of video communication, video can be
transmitted from a UA to multiple receivers.
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.
ISO/IEC 4005­1, Telecommunications and information exchange between systems — Unmanned aircraft
area network (UAAN) — Part 1: Communication model and requirements
ISO/IEC 4005­2, Telecommunications and information exchange between systems — Unmanned aircraft
area network (UAAN) — Part 2: Physical and data link protocols for shared communication
ISO/IEC 4005­3, Telecommunications and information exchange between systems — Unmanned aircraft
area network (UAAN) — Part 3: Physical and data link protocols for control communication
ISO 21384­4, Unmanned aircraft systems — Part 4: Vocabulary
3 Terms and definitions
For the purposes of this document, the terms and definitions defined in ISO/IEC 4005-1, ISO/IEC 4005-2,
ISO/IEC 4005-3, ISO 21384-4 and the following apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
4 Abbreviated terms
CC Control Communication
CB Coding Block
CRC Cyclic Redundancy Check
1
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ISO/IEC FDIS 4005-4:2022(E)
CSCH Control Subchannel
DL Data Link
DLL Data Link Layer
DQPSK Differential Quadrature Phase Shift Keying
DS Dedicated Slot
FN Frame Number
GF Galois Field
PCCC Parallel Concatenated Convolutional Code
PB Parsing Block
PH Parsing Header
PKH Packet Header
PN Pseudo Noise
SA Source Address
SC Shared Communication
SRRC Square Root Raised Cosine
TSB Tone Slot Block
UTC Coordinated Universal Time
VC Video Communication
VSCH Video Subchannel
5 Physical layer
5.1 Channel and frame structure for data channel
5.1.1 The number of data channels and bandwidth
The number of data channels is L. L is greater than or equal to one. The bandwidth of one data channel
is 5 MHz as shown in Figure 1. The L is determined in the upper layer.
Figure 1 — Data channels in frequency region
2
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ISO/IEC FDIS 4005-4:2022(E)
5.1.2 Frame structure
The frame length of the data channel is 1 sec and consists of 250 slots. The one slot time T is 4 ms. A
s
data slot block has 2 slots. Therefore, there are 125 data slot blocks in one frame, and the data slot block
is 8 ms in length as shown in Figure 2. The frame number, FN changes from 0 to 59 in a 1 min interval,
and has the same value as the second of the current time.

a
1 frame, T = 1 second = 250 T .
f s
b
1 slot, T = 4 ms.
s
c
1 slot block, T = 8 ms = 2 T .
sb s
Figure 2 — Data channel frame structure
5.1.3 Slot transmit time mask
The transmission time mask of a slot is as shown in Figure 3.
Key
T 0 μs
0
T , T , T , T symbol offset from T
1 2 3 4 0
a
4 ms.
b
Modulated signal.
Figure 3 — The transmission time mask of a slot
T , T , T , T are symbol offsets from T and symbol time is 1/2688000‬ sec. Each value is as follows: T
1 2 3 4 0 1
is 8, T is 10380, T is 10388, T is 10752.
2 3 4
T is 0 μs as the start time of the slot and the power amplifier is gated on and unmodulated fine signals
0
begin to be transmitted. T is an offset at which modulation signal transmission starts. T is an offset
1 2
at which the transmission of the modulated signal ends. T is an offset at which the power amplifier is
3
gated off, and transmission of unmodulated fine signals is stopped. The transmit power of T to T , T to
0 1 2
T shall be at least 50 dB less than the modulation signal transmit power.
3
3
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ISO/IEC FDIS 4005-4:2022(E)
5.1.4 Sub channels
a
V
x
b
V
x,0
c
V
x,1
d
V
x,8
e
V
x,9
Figure 4 — Sub channel structure of video communication in even frame
One data channel consists of 10 subchannels as shown in Figure 4. Subchannel y of video channel x is
composed of the following slot set.
V = S , S , S , …, S
x,y x,z x,z+10 x,z+20 x,z+240
ye, venframe
z= (1)
yy+−12(mod )/22× , oddframe
 
 
where
y is subchannel number, y=0, 1, …, 9;
S is slot z of video channel x.
x,z
4
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ISO/IEC FDIS 4005-4:2022(E)
The subchannel consists of 25 slots, the i­th slot resource of the subchannel y of the channel x is indicated
by SR , and the subchannel y of frequency channel x is indicated by V . Therefore, V is as follows.
x,y,i x,y x,y
V = SR , SR , …, SR (2)
x,y x,y,0 x,y,1 x,y,24
where SR  is i­th slot resource of subchannel y of channel x, i=0, …, 24.
x,y,i
All slots of video channel are downlink.
5.1.5 Dedicated subchannels
The upper layer can predetermine one or several subchannels as dedicated subchannels. In this case,
the tone subslot set mapped with the dedicated subchannel is not used as a competition tone and can be
used for other purposes.
Dedicated subchannel information is received from an upper layer through UPtoDL.
InfoDedicatedChannel.
5.2 Channel and frame structure for tone channel
5.2.1 General
The tone channel of video communication means a competitive tone channel. The tone channel used
for video communication resource allocation and the tone channel used for control communication
resource allocation are the same channel (see ISO/IEC 4005­3).
5.2.2 Slot transmit power
The maximum transmission power PmaxTCH of the tone slot mapped to the video subchannel (VSCH)
is received as UPtoDL.InfoPowerParamVCH from the upper layer. The power of the tone subslot signal
is determined by adding the PTX_VCHTCH_differ value to the transmission power of the mapped VSCH.
5.3 Encoding procedure
The encoding follows the following procedure. CRC encoding, turbo coding, rate matching, interleaving,
modulation mapping, burst mapping, and pulse mapping are performed in this order as shown in
Figure 5.
Figure 5 — Encoding procedure
The number of symbols according to each encoding stage is shown in Table 1, where the encoding
input consists of two code blocks, CB0 and CB1 as shown in Figure 14. Each code block undergoes CRC
encoding, turbo coding, rate matching, interleaving, and modulation mapping processes, respectively.
The length of each code block in these processes is 4094, 4928, 9868, 9856, 9856, and 4928. The two
code blocks are merged into one burst during burst mapping.
5
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ISO/IEC FDIS 4005-4:2022(E)
Table 1 — Number of symbols at each encoding stage
Stage Number of symbols
a 4904 × 2 (binary)
b 4928 × 2 (binary)
c 9868 × 2 (binary)
d 9856 × 2 (binary)
e 9856 × 2 (binary)
f 4928 × 2 (complex)
g 10364 (complex)
h 10372 × OS (complex)
5.3.1 CRC encoding
The input bits are defined as a , a , a , a , …, a and parity bits as p , p , p , p , …, p where A represents
0 1 2 3 A­1 0 1 2 3 23
the number of input sequences. Parity bits are generated through CRC generation polynomial as follows.
24 22 6 5
g (D) = D + D + D + D + D + 1 (3)
CRC
The encoding performed through the cyclic generator polynomials has a systematic form as follows.
The resulting polynomial has zero remainder when it is divided by g (D) on GF(2).
CRC
A+23 A+22 24 23 22 1
a D + a D + … + a D + p D + p D + … + p D + p (4)
0 1 A­1 0 1 22 23
After CRC insertion, bits are represented by b , b , b , b , …, b (where B = A + 24), and the relationship
0 1 2 3 B­1
between a and b is as follows.
k k
af, orkA=−01,,,21,
k
b = (5)
k
Pf, orkA=+,,,AA12++,A 23
kA−
5.3.2 Turbo encoding
The turbo encoder consists of Parallel Concatenated Convolutional Code (PCCC) with two 8­state
c
...