####### United States of America

DRAFT PROPOSAL FOR THE WORK OF THE CONFERENCE

**WRC-07 Agenda Item 1.8 (Res. 145):** *to consider the results of ITU-R
studies on technical sharing and regulatory provisions for the
application of high altitude platform stations operating in the bands
27.5-28.35 GHz and 31‑31.3 GHz in response to Resolution **145**
**(WRC‑03),** and for high altitude platform stations operating in the
bands 47.2-47.5 GHz and 47.9-48.2 GHz in response to Resolution **122
(Rev.WRC‑03)**;*

**Background Information**: Concerning Resolution **145**, WRC-2000
decided to adopt provisions for the operation of HAPS on a
non-interfering/non-protected basis in the bands 27.5-28.35 and 31-31.3
GHz in Region 3, but did not allow operation in the entire bands until
studies could be completed to determine how best to protect existing
services in these and nearby frequency bands. WRC-03 further refined
these provisions by deciding to limit HAPS operation to 300 MHz in a
specified direction in each of these two bands, retaining the
requirement for HAPS to operate on a non-interfering/non-protected basis
in these 300 MHz segments, and adopting Resolution **145 (WRC-03)**,
which created the possibility of allowing Region 2 administrations to
advise the Radiocommunications Bureau of their intent to implement HAPS
systems within the bands 27.5-28.35 and 31-31.3 GHz. Administrations
intending to implement HAPS in these bands are to seek the explicit
agreement of concerned administrations in accordance with *resolves* 4
of this Resolution.

Under Resolution **145 (WRC-03)**, the use of HAPS within the
fixed-service allocations within the 27.5-28.35 GHz and 31-31.3 GHz
bands must be limited to 300 MHz in each band, and is subject to the
condition that such use must not cause harmful interference to, nor
claim protection from, other stations of services operating in
accordance with the Table of Frequency Allocations of Article **5**.
Furthermore, the Resolution specifies that that the development of these
other services shall proceed without constraints by HAPS operating
pursuant to the Resolution. This Resolution also calls for the
identification of a common 300 MHz within the 27.5-28.35 GHz band for
use by HAPS. With respect to the band 31-31.3 GHz, Resolution **145
(WRC-03)** specifies that systems using HAPS in Region 2 in the band
31-31.3 GHz must not cause harmful interference to the radio astronomy
service having a primary allocation in the band 31.3-31.8 GHz, taking
into account the protection criterion given in Recommendation
ITU‑R RA.769. The Resolution contains limits on the level of unwanted
power density into the HAPS ground station antenna in the band
31.3-31.8 GHz in order to ensure the protection of satellite passive
services.

**Proposal**:

#### USA/ /1 MOD

**5.537A** In Bhutan, Korea (Rep. of), the Russian Federation,
Indonesia, Iran (Islamic Republic of), Japan, Kazakhstan, Lesotho,
Malaysia, Maldives, Mongolia, Myanmar, Uzbekistan, Pakistan, the
Philippines, Kyrgyzstan, the Dem. People's Rep. of Korea, Sri Lanka,
Thailand and Viet Nam, the allocation to the fixed service in the
band 27.5-2[7.8]{.underline}~~8.35 ~~GHz may also be used by high
altitude platform stations (HAPS). ~~The use of HAPS within the
band 27.5-28.35 GHz is limited, within the territory of the countries
listed above, to a single 300 MHz sub‑band.~~ Such use of 300 MHz of the
fixed-service allocation by HAPS in the above countries is further
limited to operation in the HAPS-to-ground direction and shall not cause
harmful interference to, nor claim protection from, other types of
fixed-service systems or other co-primary services. Furthermore, the
development of these other services shall not be constrained by HAPS.
See Resolution **145 ([Rev.]{.underline}WRC‑0[7~~3~~]{.underline})**.

**Reasons:** WRC-03 called for the identification of a common 300 MHz
band, within the 27.5-28.35 GHz band, for use by HAPS in those countries
wishing to implement such service. Such identification will help to ease
the implementation and harmonization of HAPS in those countries.
Identifying the lowest 300 MHz segment for potential use by HAPS
maximizes the amount of contiguous FSS spectrum in the 27.5-30.0 GHz
band that would not be constrained domestically in any way as a
consequence of any potential use of the band by HAPS.

#### USA/ /2 MOD

**5.543A** In Bhutan, Korea (Rep. of), the Russian Federation,
Indonesia, Iran (Islamic Republic of), Japan, Kazakhstan, Lesotho,
Malaysia, Maldives, Mongolia, Myanmar, Uzbekistan, Pakistan, the
Philippines, Kyrgyzstan, the Dem. People's Rep. of Korea, Sri Lanka,
Thailand and Viet Nam, the allocation to the fixed service in the
band 31-31.3 GHz may also be used by systems using high altitude
platform stations (HAPS) in the ground-to-HAPS direction. The use of the
band 31-31.3 GHz by systems using HAPS is limited to the territory of
the countries listed above and shall not cause harmful interference to,
nor claim protection from, other types of fixed-service systems, systems
in the mobile service and systems operated under No. **5.545**.
Furthermore, the development of these services shall not be constrained
by HAPS. Systems using HAPS in the band 31-31.3 GHz shall not cause
harmful interference to the radio astronomy service having a primary
allocation in the band 31.3-31.8 GHz, taking into account the protection
criterion as given in Recommendation ITU‑R RA.769. In order to ensure
the protection of satellite passive services, the level of unwanted
power density into a HAPS ground station antenna in the band
31.3-31.8 GHz shall be limited to 106 dB(W/MHz) under clear-sky
conditions, and may be increased up to ‑100 dB(W/MHz) under rainy
conditions to take account of rain attenuation, provided the effective
impact on the  passive satellite does not exceed the impact under clear
sky conditions given above. See Resolution **145**
(**[Rev.]{.underline}WRC-0[7]{.underline}~~3~~**).

**Reasons:** Consequential to the revision of Resolution **145**.

#### USA/ /3 MOD

RESOLUTION 145 ([Rev.]{.underline}WRC-[07~~3~~]{.underline})

Potential use of the bands 27.5-2[7.8]{.underline}~~8.35~~ GHz and
31-31.3 GHz\
by high altitude platform stations (HAPS)\
in the fixed service

The World Radiocommunication Conference (Geneva,
200[7]{.underline}~~3~~),

considering

*a)* that WRC‑97 made provision for the operation of HAPS, also known as
stratospheric repeaters, within a 2  300 MHz portion of the
fixed-service allocation in the bands 47.2-47.5 GHz and 47.9-48.2 GHz;

*b)* that WRC‑97 adopted No. **4.15A** specifying that transmissions to
or from HAPS shall be limited to the bands specifically identified in
Article **5**;

*c)* that at WRC‑2000, several countries in Region 3 and one country in
Region 1 expressed a need for a lower frequency band for HAPS due to the
excessive rain attenuation that occurs at 47 GHz in these countries;

*d)* that ~~at the present Conference,~~ [some]{.underline} countries in
Region 2 [have]{.underline} also expressed an interest in using a
frequency range lower than those referred to in *considering a)*;

*e)* that, in order to accommodate the need expressed by the countries
referred to in *considering c)*, WRC‑2000 adopted Nos. **5.537A** and
**5.543A**, which were modified at [WRC-03 and then again at
WRC-07]{.underline} ~~this Conference~~ to permit the use of HAPS in the
fixed service ~~within 300 MHz of spectrum~~ in the band
27.5-2[7.8]{.underline}~~8.35~~ GHz and in the band 31-31.3 GHz in
certain Region 3 countries and in one Region 1 country on a non-harmful
interference, non-protection basis;

*f)* that the bands 27.5-2[7.8]{.underline}~~8.35~~ GHz and 31-31.3 GHz
are already heavily used or planned to be used by a number of different
services and a number of other types of applications in the fixed
service;

*g)* that while the decision to deploy HAPS can be taken on a national
basis, such deployment may affect neighbouring administrations,
particularly in small countries;

*h)* that the 31.3-31.8 GHz band is allocated to the radio astronomy,
Earth exploration-satellite (passive) and space research (passive)
services, and that [WRC-03]{.underline} ~~this Conference~~ amended
No.** 5.543A** to specify signal levels that would protect satellite
passive services and radio astronomy stations;

*i)* that ITU‑R has conducted studies dealing with sharing between
systems using HAPS in the fixed service and other types of systems in
the fixed service in the bands 27.5-2[7.8]{.underline}~~8.35~~ GHz and
31-31.3 GHz leading to Recommendation ITU‑R F.1609;

*j)* that results of some ITU‑R studies indicate that, in the bands
27.5-2[7.8]{.underline}~~8.35~~ GHz and 31-31.3 GHz, sharing between
fixed-service systems using HAPS and other conventional fixed-service
systems in the same area will require appropriate interference
mitigation techniques to be developed and implemented;

*k)* that ITU‑R has conducted studies dealing with compatibility between
systems using HAPS and the passive services in the 31.3-31.8 GHz band
leading to Recommendations ITU‑R F.1570 and ITU‑R F.1612;

*l)* that ITU‑R has produced Recommendation ITU‑R SF.1601 containing a
methodology for evaluating interference from the fixed-service system
using HAPS into GSO FSS systems in the band
27.5-2[7.8]{.underline}~~8.35 ~~GHz ~~in order to facilitate further
studies~~;

*m)* that HAPS technical ~~and regulatory~~ issues should continue to be
studied in order to determine appropriate measures for protecting the
fixed service and other co-primary services in the band
27.5-2[7.8]{.underline}~~8.35~~ GHz;

~~*n)* that pending the completion of studies, administrations in Region
2 may wish to consider deployment of HAPS systems in the fixed service
within 300 MHz of spectrum at 27.5-28.35 GHz and in 300 MHz of spectrum
at 31-31.3 GHz and to have some provisional means by which to authorize
such use of HAPS in their territories,~~

~~noting~~

~~that systems using HAPS may operate in the bands 27.5-28.35 GHz and
31-31.3 GHz under No. **4.4**,~~

resolves

~~1 to invite WRC‑07 to review the results of the studies specified
below and consider appropriate refinement of the regulatory provisions
for the use of HAPS within the bands 27.5-28.35 GHz and 31-31.3 GHz;~~

[1]{.underline}~~2~~ that, notwithstanding No. **4.15A**, in Region 2
the use of HAPS within the fixed-service allocations within the
27.5-2[7.8]{.underline}~~8.35~~ GHz and 31-31.3 GHz bands shall ~~be
limited, pending the completion of the studies specified in *invites
ITU‑R* 1 below, to 300 MHz in each band, that such use shall~~ not cause
harmful interference to, nor claim protection from, other stations of
services operating in accordance with the Table of Frequency Allocations
of Article **5**, and, further, that the development of these other
services shall proceed without constraints by HAPS operating pursuant to
this Resolution;

[2]{.underline}~~3~~ that~~, pursuant to *resolves* 2 above,~~ any use
by HAPS of the fixed-service allocation at
27.5-2[7.8]{.underline}~~8.35~~ GHz [pursuant to *resolves* 1
above]{.underline} shall be limited to operation in the HAPS-to-ground
direction, and that any use by HAPS of the fixed-service allocation at
31-31.3 GHz shall be limited to operation in the ground-to-HAPS
direction;

[3]{.underline}~~4~~ that~~, on a provisional basis,~~ the
administrations listed in Nos. **5.537A** and **5.543A** and those
administrations in Region 2 which intend to implement systems using HAPS
in the fixed service in the bands 27.5-2[7.8]{.underline}~~8.35~~ GHz
and 31-31.3 GHz shall seek explicit agreement of concerned
administrations with regard to their primary services to ensure that the
conditions in Nos. **5.537A, 5.543A**, *resolves* [1]{.underline}~~2~~
and *resolves* [4]{.underline}~~5~~ are met;

[4]{.underline}~~5~~ that systems using HAPS in the band 31-31.3 GHz, in
accordance with *resolves *[1]{.underline}~~2~~ above, shall not cause
harmful interference to the radio astronomy service having a primary
allocation in the band 31.3-31.8 GHz, taking into account the protection
criterion given in Recommendation ITU‑R RA.769. In order to ensure the
protection of satellite passive services, the level of unwanted power
density into the HAPS ground station antenna in the band 31.3-31.8 GHz
shall be limited to --106 dB(W/MHz) under clear-sky conditions and may
be increased up to 100 dB(W/MHz) under rainy conditions to take account
of rain attenuation, provided that effective impact on the passive
satellite does not exceed the impact under clear-sky conditions as given
above,

invites ITU‑R

~~1 to continue to conduct studies, as a matter of urgency, and taking
into account the requirements of other fixed-service systems and other
services, on the feasibility of identifying a suitable and preferably a
common 300 MHz segment of the band 27.5-28.35 GHz paired with the
300 MHz band at 31-31.3 GHz, for use by HAPS in the countries listed in
Nos. **5.537A** and **5.543A** or countries in Region 2 planning
provisional operation;~~

[1]{.underline}~~2~~ to develop, one or more ITU‑R Recommendations,
technical sharing criteria or HAPS system design conditions that are
necessary to ensure that HAPS applications in the fixed service operate
successfully on a non-harmful interference, non-protected basis in the
bands 27.5-2[7.8]{.underline}~~8.35 ~~GHz and 31-31.3 GHz;

[2]{.underline}~~3~~ to complete studies on the interference criteria
and methodology for evaluating interference from the downlink
(HAPS-to-ground direction) of systems using HAPS to the uplink of the
GSO satellite networks in the FSS within the band
27.5-2[7.8]{.underline}~~8.35~~ GHz, taking into account Recommendation
ITU‑R SF.1601 for the situations referred to in *considering l)*;

~~4 to study the regulatory provisions that might be needed in order to
address those cases where the deployment of HAPS in the fixed service in
the bands 27.5-28.35 GHz and 31-31.3 GHz in the territory of one
administration may affect other administrations;~~

[3]{.underline}~~5~~ to continue to carry out studies on the appropriate
interference mitigation techniques for the situations referred to in
*considering j)*,

*invites administrations,*

to advise the Radiocommunications Bureau of their intention to implement
HAPS systems within the band 27.5-2[7.8]{.underline}~~8.35~~ GHz and in
the band 31-31.3 GHz, whether in countries listed in Nos. **5.537A** and
**5.543A** or in accordance with *resolves [1]{.underline}*~~2~~, and to
specify the [technical characteristics of the systems they intend to
implement]{.underline}~~frequency bands (up to 300 MHz each with the
27.5-28.35 GHz and 31-31.3 GHz bands) they intend to use for such
systems~~,

*instructs the Radiocommunications Bureau,* to publish in the
International Frequency Information Circular (BR IFIC) a list of
administrations who have so advised, and to publish the information on
HAPS implementation received from administrations which intend to
implement systems using HAPS in the fixed service in the bands
27.5-2[7.8]{.underline}~~8.35 ~~GHz and 31-31.3 GHz.

**Reasons:** Changes to frequency ranges throughout, deletion of
*invites 1,* and other minor changes are consequential to the
modification of RR No, **5.537A**. Changes to *invites administrations*
are proposed to clarify that administrations are to supply technical
details of their systems along with an indication of their intention to
implement HAPS in these frequency bands.