World Radiocommunication Conference 2000

Use of high altitude platform stations providing IMT-2000 in the bands
1 885-1 980 MHz, 2 010-2 025 MHz and 2 110-2 170 MHz in Regions 1
and 3 and 1 885-1 980 MHz and 2 110-2 160 MHz in Region 2

The World Radiocommunication Conference 2000 (Istanbul, 2000),

considering

a) that the bands 1 885-2 025 MHz and 2 110-2 200 MHz are identified in No. S5.388 as intended for use on a worldwide basis for IMT-2000, including the bands 1 980-2 010 MHz and 2 170-2 200 MHz for the satellite component of IMT-2000;

b) that a high altitude platform station (HAPS) is defined in No. S1.66A as "a station located on an object at an altitude of 20 to 50 km and at a specified, nominal, fixed point relative to the Earth";

c) that HAPS may offer a new means of providing IMT-2000 services with minimal network infrastructure as they are capable of providing service to a large footprint together with a dense coverage;

d) that the use of HAPS as base stations within the terrestrial component of IMT-2000 is optional for administrations, and that such use should not have any priority over other terrestrial IMT-2000 use;

e) that, in accordance with No. S5.388 and Resolution 212 (Rev.WRC-97), administrations may use the bands identified for IMT-2000, including the bands referred to in this resolution, for stations of other primary services to which they are allocated;

f) that these bands are allocated to the fixed and mobile services on a co-primary basis;

g) that ITU-R has studied sharing and coordination between HAPS and other stations within IMT-2000, has considered compatibility of HAPS within IMT-2000 with some services having allocations in the adjacent bands, and has established Recommendation ITU-R M.1456;

h) that ITU-R did not address sharing and coordination between HAPS and some existing systems, particularly PCS (personal communications service), MMDS (multichannel multipoint distribution service) and systems in the fixed service, which are currently operating in some countries in the bands 1 885-2 025 MHz and 2 110-2 200 MHz;

i) that, in accordance with No. S5.BBB, HAPS may be used as base stations within the terrestrial component of IMT-2000 in the bands 1 885-1 980 MHz, 2 010-2 025 MHz and 2 110-2 170 MHz in Regions 1 and 3 and 1 885-1 980 MHz and 2 110-2 160 MHz in Region 2; the use by IMT-2000 applications using HAPS as base stations does not preclude the use of these bands by any station in the services to which they are allocated and does not establish priority in the Radio Regulations,

recognizing

that the values in resolves 1 may not be appropriate for the protection of some stations operating in these bands in the fixed and mobile services,

resolves

1 that:

a) for the purpose of protecting certain stations operating within IMT-2000 in neighbouring countries from co-channel interference, a HAPS operating as a base station to provide IMT-2000 shall not exceed a provisional co-channel power flux-density (pfd) of �121.5 dB (W/(m² � MHz)) at the Earth�s surface outside an administration�s borders unless agreed otherwise by the administration of the affected neighbouring country;

b) a HAPS operating as a base station to provide IMT-2000, in order to protect fixed stations from interference, shall not exceed the following provisional values of out-of-band pfd at the Earth�s surface in the bands 2 025-2 110 MHz:

� �165 dB(W/(m² � MHz)) for angles of arrival (q ) less than 5� above the horizontal plane;

� �165 + 1.75 (q � 5) dB (W/(m² � MHz)) for angles of arrival between 5� and 25� above the horizontal plane; and

� �130 dB(W/(m² � MHz)) for angles of arrival between 25� and 90� above the horizontal plane;

2 that, as of the end of WRC-03, such a HAPS shall operate only in accordance with such limits as are confirmed or, if appropriate, revised by WRC-03, irrespective of its date of bringing into use;

3 that administrations wishing to implement HAPS within a terrestrial IMT-2000 system shall comply with the following:

a) for the purpose of protecting certain stations operating within IMT-2000 in neighbouring countries from co-channel interference, administrations using HAPS as base stations within IMT-2000 shall use antennas that comply with the following antenna pattern:

G(y ) = G_m � 3(y /y _b)²     dBi for     0� � y � y ₁

G(y ) = G_m + L_N                dBi for     y ₁ < y � y ₂

G(y ) = X � 60log (y )      dBi for     y ₂ < y � y ₃

G(y ) = L_F                          dBi for     y ₃ < y � 90�

where:

G(y ): gain at the angle y from the main beam direction (dBi)

G_m:     maximum gain in the main lobe (dBi)

y _b:     one-half of the 3 dB beamwidth in the plane considered (3 dB below G_m) (degrees)

L_N:     near side-lobe level in dB relative to the peak gain required by the system design, and has a maximum value of �25 dB

L_F:     far side-lobe level, G_m � 73 dBi

y ₁ = y _b              degrees

y _{2 =} 3.745 y _b                         degrees

X = G_m + L_N + 60log (y ₂)        dBi

y ₃              degrees

The 3 dB beamwidth (2y _b) is again estimated by:

(y _b)² = 7442/(10^0.1Gm)            degrees²

where G_m is  the peak aperture gain (dBi);

b) for the purpose of protecting mobile earth stations within the satellite component of IMT-2000 from interference, a HAPS operating as a base station to provide IMT-2000, shall not exceed an out-of-band pfd of �165 dB (W/(m² � 4 kHz)) at the Earth�s surface in the bands 2 160-2 200 MHz in Region 2 and 2 170-2 200 MHz in Regions 1 and 3;

4 that administrations wishing to implement HAPS within a terrestrial IMT-2000 system shall, prior to their bringing into use, take into account in their bilateral coordination with affected neighbouring administrations the operation and growth of existing and planned systems in the fixed and mobile services having allocations on a primary basis;

5 that, for the purpose of protecting fixed service stations operating in neighbouring countries from co-channel interference, administrations wishing to implement HAPS within a terrestrial IMT-2000 system shall, pending the review by WRC-03 of the studies mentioned below, take full account of the relevant ITU-R Recommendations relating to protection values for fixed stations (see Recommendation ITU-R F.758),

invites ITU-R

to complete, as a matter of urgency, additional, regulatory, operational and technical studies on sharing criteria for HAPS with other systems in the bands 1 885-1 980 MHz, 2 010-2 025 MHz and 2 110-2 170 MHz in Regions 1 and 3 and 1 885-1 980 MHz and 2 110-2 160 in Region 2, and in adjacent bands to allow revision of the values in resolves 1, and the develop appropriate regulatory and technical provisions to allow the coordination mentioned in resolves 4 and to report on the results of these studies in time for consideration by WRC-03.