IARU Region 3 HF Band Plan Committee
Amateur Service - HF Amateur Band Planning
40m Band Harmonisation Challenges
Executive Summary
The IARU Region 3 HF Band Plan committee and the IARU Region 3 board have long noted the
problems on 40m of mis-alignment of activity types between national and even inter-regional band
plans on the 40m band. This paper is the start of a process investigating whether improvements canbe made to the 40m band plan that improve:••••

Global harmonisation of activity
Recognise the increase in demand for data mode band space
Consider how to improve the availability and usability of band segments set aside to support
Emergency Communications
Consider ways of reducing conflict between contest activities and all other band users

The paper sets forth the case for improved harmonisation and attempts to define empirical based
methods for assessing required band segment capacity for each of the main operating mode groups,
and then proposes several solutions that demonstrate different ways of solving the problem.
Amateur operators, IARU Member societies and regional clubs are all invited to contribute their
feedback and are, in particular, asked to consider the questions posed at the end of this paper.

Background
Amateur radio activity on the HF spectrum has always been carried out on a non-assigned /frequency agile basis, where individual operators have the autonomy to choose what frequencies
they wish to operate on. However, given the diversity of activity types within the amateur service, it
is inevitable that conflicts will arise between different user groups that are focused on diverse andincompatible activities.
To address these conflicts, the amateur service, through the efforts of the IARU, has published band
plans that define preferred band segments for each major activity type. The aim is to organise
amateur activity such that incompatible modes each have their own area to operate in. This reduces
the probability that one stations activities will cause interference (potentially unwittingly) toanother.

Global Harmonisation
Today, the amateur radio band plans published by the IARU, guide amateur radio operators on
which band segment each activity should use. For example:•••

CW or Morse Code – sending text-based information using aural based codes
Data-modes – focused on primarily machine to machine communication
Voice – sending speech-based information (in both analogue and digital formats)Band segment alignment of these three fundamental activities globally has been a key objective of
IARU for many years now.

40m Band Challenges
The Amateur Service 7000-7200 kHz band is considered an example of one of the more disorganised bands on a global basis. The main problems affecting basic band plan alignment can besummarised as:1) inconsistent IARU member society band plans.
2) specific national regulatory conditions (e.g. the FCC in the USA)3) legacy band plan allocations that haven’t been revised following the band expansion granted
at WRC2003 (prior to which the 40m band was only 100 kHz wide)
In addition to these basic issues, the other more recent challenge has been the shift in generalamateur radio activity towards wider use of data modes of communication. In particular, theexplosion of data modes has also occurred on an ad hoc basis without following the global band
plans. The most glaring example of this is the 7074 kHz WSJT data activity in what is spectrum
currently set aside for voice communications in the IARU band plans.
It is through attempting to reduce the inconsistencies and making a concerted effort to deliver a
harmonised global 40m band plan that many of the problems should be solved. At the same time, it
is worth reconsidering the amount of spectrum allocated per activity to ensure that each mode has afair share of the available spectrum based on current activity.

Spectrum segment definition – band position per mode
From the diagram below, you can see the obvious lack of alignment between nations within Region
3, and indeed between the three main regions. This is most pronounced when considering the data
mode segments.
For example, the legacy 10 kHz data segment at 7030 kHz persists in several parts of Region 3. The
corresponding misalignment in the voice segments results in substantial cross mode interference
between data-modes and voice operators throughout the 7040-7080 kHz band segment (particularly
in Region 3).
It is therefore clear that action needs to be taken to reduce the position conflicts that currently exist.

40m Band Plan Comparisons – IARU Global vs Region 3 Member Domestic Plans

CW
Data
Voice
Special Use
WSJT

Spectrum segment definition – bandwidth per mode
The disparity in bandwidth allocated to the different mode families is also views as a significant
contributor to the problem across region 3 and the world. This is compounded by certain data mode
activity occurring outside the IARU data mode sub-bands (particularly the WSJT calling frequency on
7074 kHz).
Today we find the following quantities of spectrum defined in the various band plans:Country / Region
Region 1
Region 2
Region 3
Japan
Australia
BangladeshIndonesia
South Korea
Malaysia
United States

CW
40 kHz40 kHz
30 kHz
30 kHz40 kHz40kHz + 39 kHz
25 kHz
25 kHz
25 kHz
50 kHzData Modes
10 kHz *1
10 kHz
10 kHz
15 kHz
20 kHz1 kHz + 45 kHz
15 kHz
5 kHz
15 kHz75 kHzVoice
150 kHz150 kHz
170 kHz *3
155 kHz150 kHz *4
75 kHz160 kHz
170 kHz160 kHz75 kHz *2

NOTES:*1 is actually wider but not on a data modes exclusive only basis*2 It is worth noting that the USA has access to the band as high as 7300 kHz – so the real voice capacity for USA amateurs is 175 kHz*3 Region 3 has an overlapping Voice and data modes allocation between 7030-7050 kHz*4 Australia has 10 kHz of the data modes and voice modes allocation overlapping

What is particularly noteworthy is how little spectrum is set aside in the band plans for data modes.
Again, this almost appears to be a legacy of the band plan pre-expansion at WRC2003.
The challenge today, however, is to decide on a method of determining an equitable redistributionof spectrum per activity. The aim, therefore, is to try and find a suitable activity indicator orspectrum demand indicator that all user groups will accept as valid.

Band Segment Capacity Demand Modelling
Given that the amateur service is a non-assigned service, (i.e. stations have autonomy to pick theiroperating frequency within the band segment), you can’t use any form of quantity of licensed
stations-based allocation per kHz model to determine how much spectrum is in use for a given
operating mode. The number of licenced stations has no bearing on band activity or interest in aparticular mode.
To overcome this fundamental problem, a channel-based activity model is discussed for data modes
and an activity-based model derived from proportionate logging data from a public global databaseis used for CW and SSB. Combining to two should see a way forward to equitable band distribution.

Stage 1 - Data Capacity Assessment
Considering the amount of general published information about where to find data mode activity on
the bands (e.g. Winlink node listings plus WSJT operating channels for Fox and normal mode traffic),

it is considered at least feasible to estimate the amount of spectrum that might be required for data
modes on a channel-by-channel basis.
For example, when examining typical data traffic:
•
•
•

•

FT8 – traffic is usually on a main 3kHz channel but can regularly have up to 2 DX-pedition
stations active at the same time. This means that up to 9 kHz needs to be made available for
FT8 data alone.
FT4 usually only requires one 3kHz channel
WinLink and similar Store and Forward/Mailbox based activity – when operated in wideband
VARA mode, occupies up to 2.7kHz / channel. Based on the number of reported active
gateways1 on disparate frequencies today, it could be argued that a minimum of 10 kHz
should be set aside for Winlink activity. Allocating dedicated space to this mode is also inalignment with improving Emergency Communications (EmComm) support by the amateur
service as there is substantial evidence in at least some areas of the world that HF datasystems are very valuable means of communications in emergency relief type operations.
Ad Hoc data – PSK/RTTY/Olivia/JS8Call etc is harder to assess, however it is not uncommon
to see at least 1-2 QSOs in each of these modes active during certain times of the day. On
that basis, if we allowed 2kHz for PSK, 2 kHz for general RTTY, 2kHz for Olivia and 2kHz for
JS8Call we should then set aside ~8 kHz for general data traffic on the band.

All up, this paints a picture of data demand of ~30 kHz of general demand for data spectrum perband. (note this is not considering the temporary high demand situations created during contests).
That is a far cry from what is currently available on 40m, especially given that on a harmonised basis,
only 16 kHz is notionally available across all three regions. (and that is considering the global FT8channel notionally harmonised by default, despite not being included in the IARU band plans at thistime).

Stage 2 - CW and SSB Capacity Assessment
Assessing the capacity requirements of each of these modes is somewhat more difficult. The traffic
is completely ad-hoc and isn’t generated by a “channelised” access mechanism (unlike data modes
such as WinLink and WSJT).

1

https://www.winlink.org/RMSChannels?qt-live_winlink_information=1#qt-live_winlink_information

To overcome the problem, the method chosen for this estimation was to look at the proportion ofactivity being logged on each mode in Clublog2. From the statistics available, the following can bederived:

Mode
CW
SSB
FT8
FT4
Data (other)

Clublog
activity
proportion
15%
13%
60%
7%
5%

Bandwidth requiredfor 1 transmission
400 Hz3000 Hz
50 Hz 3
83.3 Hz 3
400 HzUsing these percentages and bandwidths, a proportional allocation of spectrum can be calculated
based on activity for each mode.

Overall Spectrum Demand by Mode – 40m
Taking the traffic estimations for all modes above, including the typical required occupied
bandwidths, a derivation of what is a fair proportion of the spectrum for each mode can then bedevised:Mode

Clublog
Measured
Activity Factor

ChannelBandwidth
Required

CW
SSB
FT8
FT4
Data (other)
Winlink 4

15%
13%
60%
7%
5%
NA

400 Hz3 kHz
50 Hz
83.3 Hz
400 Hz500-2700 Hz

Bandwidth
adjusted
Activity
Factor %
12%
73%
6%
1%
2%

Calculated
40m BandSpectrum Allocation
by Mode24.2 kHz146.8 kHz12.1 kHz
2.8 kHz
4 kHz
10 KHz40m Band
Proposed
Allocation
by Mode25 kHz145 kHz
30kHz(all Data)

The interesting outcome is that the figure of 30 kHz of proportional capacity being made available
for data modes in fact matches the earlier channel-based estimation. This adds weight to anargument that data modes are currently being starved of clean spectrum, which plays out as ongoing
conflict and interference arising between data mode operators and other spectrum users.
Ultimately, this provides evidence that the proportion of spectrum assigned today per mode
category no longer reflect the proportion of activity types actually occurring on the band. It certainlypresents a case for considering a rebalancing of how much spectrum is required for each mode.

2

https://clublog.org/

3 It is noted that these modes with their error correction can operate with overlapped transmissions, however for the

purposes of this estimation, noting the channel demand described earlier, this model has used the bandwidth figure as an
uncontested bandwidth use figure in a broader % occupancy figure to simplify the assessments.
4
Winlink’s spectrum estimation was described above based on registered stations not logged traffic, as Winlink does nothave its traffic typically logged in Clublog.

Activity Position within the 40m band
Having reached the conclusion that rebalancing is required, then the issue to be tackled is how toalign the spectrum for each activity. Specifically, what is the best way to arrange the spectrum usage
in terms of minimising conflict between disparate modes particularly at usage borders.
Sime existing rules worth considering and continuing would be:
1) CW operation should always start from the bottom of the band. (This is a long-standing
position that doesn’t need to change)
2) SSB operation should always start from the top of the band – (again this is also a longstanding arrangement)
3) Data modes form the boundary between CW/SSB. The high spectrum utilisation, particularlyof the primary FT8 calling channel, in fact acts today as a useful marker in many bands forthe border between CW and other operating modes.
In addition, there are several problems that have always plagued band planning, specifically aroundhow to manage transient high traffic periods caused by on air events (such as contests or DXpeditions to rare locations). These can be expressed as:1) how to establish band segments that have room to dynamically flex their usage based on
demand while minimising interference to other activities. For example, multiple times in a
year, contest activity causes a significant peak in traffic on the band in the given mode being
used by a particular contest, which invariably causes the mode to take up more spectrum
that normal.
Consider how intermittent high intensity use by one mode can be at least partially
accommodated while not causing severe disruption to emergency communications activities(which are seen as one of the key drivers for regulators facilitating amateur radio’s existencein the first place in many countries).
a. the emergency communications perspective of this and the perception of theamateur service’s ability to deliver on that capability is a factor here. For example,
when considering WinLink
i. it is a technology that has been demonstrated to provide great value inhandling emergency communications traffic,
ii. it is at times difficult to deploy for such uses on the amateur bands because
every weekend contest activity comes along and interferes with Winlink
gateway stations
iii. the amateur service is therefore at risk of being overlooked by somejurisdiction’s authorities for providing EmComm capabilities because of theintra-service QRM
b. positioning spectrum for WinLink and voice EmComm activity and incentivisingcontesters to leave that spectrum clear is an important element to consider whenreplanning the band2) Given that SSB operation on the band typically has two distinct interest groups:
a. local nets (utilising what is typically near vertical incidence (NVIS) or short haul typecommunications are a very popular uses of the bandb. there is also a strong interest in DX use of the band
one needs to be aware particularly on 40m that the stations operated by both groups are notof equal capabilities.
The stations engaged in using near vertical incidence propagation to support local
communications (<1000km) do not always have equipment designed to hear or contact
weaker DX stations on the band. With activities such as contesting being DX focused, theinevitable complaints regularly arise that contest activity interferes with the who areinterested in maintaining local communications.
3) The unfortunate position in the 40m band of the international FT8 calling channel (outside
the defined IARU digital segments) has left a challenge for IARU. It would be highly desirable,
moving forward, to have the FT8 traffic on the band contained within the data mode
segments of the global band plans, not just that of one domestic country (i.e. USA). Having
said that, it is also well understood that relocating the channel today will be nearly
impossible.
Taking these considerations into account creates some complex competing challenges. The goal
here, therefore, is to find a way to satisfy as many of these as possible.

40m Band Proposals
To start the discussion, three possible options have been developed for consideration. This doesn’tmean these are the only options that could be considered, but in presenting these, the aim was toshow how many of the objectives for capacity and placement could be met given different
fundamental drivers.
Further, while are driven by different principles, it is worth noting that each of the options presented
do maintain several common core goals:
1) Each mode category is entitled to having a segment of the band dedicated to that activity(CW, Voice and Data)
2) Consideration of where to place EmComm type traffic in an attempt to limit the risk of QRM
from other amateur activity

Option A – Evolution with a fairer proportional allocation by activity
The main element of Option A is that it was modelled on the traditional approach to band planning,where the band is organised in on the existing CW, then data, then voice structure, but used the
proportional spectrum quantities described above as the foundation for a new plan.
There are quite a few negatives however with this plan. In particulara. the CW mode could be perceived to be disadvantaged (even though based on activity it
could be argued that it has too much spectrum allocated to it today).
b. It doesn’t resolve the problem of the FT8 centre of activity sitting outside of the data
segment (and fails to recognise the difficulties likely encountered in trying to move thisactivity)

c. It doesn’t preserve parts of the spectrum for “variable dynamic use” to accommodate (andwith the cooperation of the contest organisers potential containment of) contest activity
d. It doesn’t provide a particularly palatable solution for EmCom service operators who will findmost transient high load activity will likely continue to interfere with them.
e. It presents one of the more challenging existing use migration pathways for all users except
CW.
The one thing Option A did achieve was to be an evolutionary path from where the current band
plans are today.

Option B – Revolution and accommodation of new requirements
Option B is very much revolutionary rather than evolutionary, and as such has taken a very different
approach to band management> It has a different emphasis placed on different outcomes.
What does Option B do:a. It places the data band anchored to the position of the current WSJT-X call channel on 7074
in the same way it is placed on 20m (i.e. data starts at x.070).
b. The challenge of how to manage overlapping interference and disruption to EmComm
activity by contesting has been in part tackled by suggesting contest segments for CW
extend up to 7070 when CW needs more room, Data modes extend down from 7090 to
7025 when data contests need more room, and SSB contests stay above 7110 kHz as muchas possible.
i.
This only works, however, if the major contests are also prepared to cooperate andprovide incentives for contest activity to not take place in the EmCom band
segments (i.e. by providing zero points for QSOs made in those bands or evengoing as far as issuing disqualifications for operating on those frequencies).
c. The proposal accepts the fact that one of the high population areas (the USA) suffers fromsome restrictive regulations imposed by the FCC that otherwise make harmonised global
band planning extremely problematic (i.e. at least partially align the IARU band plan in a waythat accommodates the FCC restrictions).
d. The proposal seeks to address the complaints often heard from voice net and local chatfocused band users that contesters overrun their favoured band segments disrupting theiractivities. They would be given priority access to the SSB spectrum at the lower end of theband, leaving the DX and contesting activity at the higher end of the band.
The obvious problem with Option B is going to be:1) Education will be required for the SSB ops currently using 7080-7100
2) The WinLink folk operating above 7100 in the USA will need to be encouraged to move down
into 7090-7100 (now that the data bandwidth limitations have been removed in thatjurisdiction it is thought this is now possible)
IARU would also need to work with major contests to ideally see them enact penalties within thecontest rules (e.g. disqualification or earning zero points for such contacts) for operating outside thecontest band segments per mode. This is needed to help better protect EmCom activities within theamateur service, not only on 7MHz but in fact on many bands.

Options for the 40m Band Plan

CW
Data
Voice
Special Use
WSJT

Option C – Split Data Band Proposal
Option C is more about adopting the status quo into the band plan, while balancing the amount ofallocated spectrum based on mode activity demand.
What does Option C do:a. It accommodates the existing WSJT activity
What Option C does not do:a. Provide any dynamic spectrum access options
b. Promote large enough coherent spectrum blocks for each activity. Wrapping the band planaround the existing activity does not solve the identified problems that the existing activity is
generating.

Next Steps - Feedback Sought
To progress the discussion, feedback is invited on this consultation.
To assist with this process, please particularly consider the following questions:Q1. Do agree that there is merit in seeking to globally harmonise the amateur service 40mband plan?
Q2. Do you agree with the way the different quantities of spectrum for different modes has
been determined? If not, please suggest alternative models that can be considered formaking the assessments.
Q3. Do you agree that more should be done to protect EmComm frequencies particularly
from contest activity?
Q4. Do you agree that the proposals to separate out contesting and other traffic types are
suitable and would be acceptable to contest organisers?
Q5. Do you see merit in separating DX SSB activity from local communications activity(including local nets) etc?
Q6. Do you consider it appropriate to consider the “SSB” segment as a “Voice” segment, andthus in the future when digital voice modes become more prevalent, that they should rightly
belong in the SSB segment alongside SSB operators, or is there a need to consider aseparation of the “Voice” segment into analogue and digital voice?
Q7. Do you think the band plan should be more or less prescriptive about individual submodes within an operating category? (i.e. should the band plan specificallyseparate/designate WSJT, PSK, RTTY, Winlink and other data communications types?) Or issufficient to name it the data sub-band, perhaps with a couple of indicative centres ofactivity for core activities named?
Q8. Is there anything else you would like to comment on regarding this discussion paper orother concepts or ideas that haven’t been mentioned that you feel should be considered?

Next Steps
Making changes to a band plan is always a complex problem to solve. Multiple groups need to beprovided the opportunity for input and many views need to be considered.
For this proposal to proceed, the following steps have been proposed:
1. The IARU Region 3 member societies are asked to also circulate this among their members
and form individual society views which should be communicated back to the IARU Region 3
HF Band Plan committee for consideration by the consultation deadline
2. IARU Region 3 invites IARU Region 1 and 2 to form a joint multi-region committee toprogress this matter as a global IARU initiative.
3. A final multi-region proposal should be submitted for consideration by the IARU-AC and the
AC be asked to determine the most appropriate pathway for ratifying the changes on a
global basis that where possible avoids the delay of a further 3 year regional conference
cycle.
This preliminary consultation process for step 1 is now open.
10 weeks will be provided for comment, with the intention that the first formal proposal can then beformulated in time for presentation at the IARU Region 3 conference later in 2024.
If you wish to provide feedback on this consultation, please send your comments addressing theconsultation questions to:
tac@wia.org.au no later than 6th September 2024.