Committee on Radio Astronomy Frequencies

Agreement for the Period 1st May 1999 to 1st January 2006 between Iridium LLC and ESF/CRAF to co-ordinate the operations of the Iridium System and Radio Astronomy Sites that are Parties to the Framework Agreement, in order to temporarily accommodate unwanted emissions from the Iridium satellites into the band 1610.6-1613.8 MHz

Iridium LLC (hereafter "Iridium") and the European Science Foundation, acting for itself and in the name and on behalf of the ESF Associated Committee for Radio Astronomy Frequencies ("CRAF") (collectively, the "Parties"), hereby enter into this Agreement to govern the operations of the Iridium System and various radio astronomy sites in Europe for the period from 1^st May 1999 to 1^st January 2006.

CRAF represents the entities which operate radio telescopes that observe in the 1610.6-1613.8 MHz band in the following countries: France, Germany, Italy, Netherlands, Poland, Spain, Sweden and U.K.;

PREAMBLE

1.	WHEREAS, the Iridium® System is composed of a constellation of 66 non-geostationary satellites, plus orbiting spares, which have been launched and are in orbit and operational;
2.	WHEREAS, Iridium LLC and its European Gateway Operators have been authorised to use the Iridium® System to provide mobile telecommunications services in Europe using the 1621.35-1626.5 MHz band, according to CEPT ERC Decision 97(03), CEPT ECTRA Decision 97(02), MRC Recommendations and any decisions of administrations,
3.	WHEREAS, the Iridium® System operates near the band in which the radio astronomy service observes signals from various sources, including signals produced by interstellar clouds of the hydroxyl radical, i.e. from 1610.6-1613.8 MHz;
4.	WHEREAS, the status of allocations to services are given by the ITU Radio Regulations, including its provisions and footnotes;
5.	WHEREAS, the Parties entered into an Agreement on 11th August 1998 (hereafter the "Framework Agreement"), which specified that the Parties would negotiate before 1st March 1999 an Agreement for the interim period 1st March 1999 to 1st January 2006;
6.	WHEREAS, the Parties have agreed to extend the 1st March 1999 date to 1st May 1999;
7.	WHEREAS, the term "Observatories" will mean all radio astronomy stations operating at 1610.6-1613.8 MHz that are parties to this agreement;
8.	WHEREAS, the Parties anticipate that the current uses of the band 1610.6-1613.8 MHz by the Observatories, and the current uses of the band from 1621.35-1626.5 MHz by Iridium are not static and may change over time;

AGREEMENT

NOW, THEREFORE, the Parties agree to the following:

(1)			The Parties agree that Iridium will provide protection to the Observatories as described below. Iridium agrees to meet spectral power flux density levels ("Interference Levels") for the Iridium® System downlink signals within the 1610.6-1613.8 MHz band during the periods specified below:
	(a)		A level of -238 dB(W/m2/Hz) for:
		(i)	7 contiguous hours per day, 7 days a week, for the following radio astronomy sites: Nançay, France; Effelsberg, Germany; Westerbork, The Netherlands; and Jodrell Bank, UK;
		(ii)	Up to 7 contiguous hours per day, 7 days a week subject to notification of need for the following radio astronomy sites: Medicina, Noto and Sardinia, Italy; Torun, Poland; Yebes and Robledo, Spain; and Onsala, Sweden;
		(iii)	2 weekend days per month, for radio astronomy sites referred to in (i);
		(iv)	Up to 2 weekend days per month subject to notification of need for radio astronomy sites referred to in (ii);
		(v)	Up to a total of 30 additional hours per year subject to notification of need for the radio astronomy stations referred to in (i) and (ii);
	(b)		A level of -224 dB(W/m2/Hz) every weekend for the radio astronomy stations referred to in a(i) and a(ii);
	(c)		Iridium will choose the contiguous 7 hours per day referred to in (a)(i) and (a)(ii) above upon at least 90 days notice. Iridium will also choose the 2 weekend days each month referred to in (a)(iii) and (a)(iv) above upon at least 90 days notice. Under exceptional circumstances notice may be given 2 weeks in advance. The chosen hours and weekend days will be the same for all the Observatories.
	(d)		The Parties agree that CRAF will notify Iridium LLC, pursuant to (1)(a)(ii), (iv) and (v), in writing at which dates and times the Iridium out-of-band emissions shall not exceed certain levels specified in (1)(a)(ii), (1)(a)(iv) and (1)(a)(v) above. This notification shall be provided no more than once a month and at least 30 days in advance of the date when protection is needed, except that up to two times per calendar year, two weeks notice will be sufficient. The notification document shall be properly certified through the signature of a CRAF designated responsible person. CRAF may send copies of the notifications to FCC and CEPT (ECTRA/ERC) for information.
	(e)		The Parties agree to evaluate the effectiveness of the agreed upon procedures and may share the appropriate information in this regard with the other party.
	(f)		The Parties further agree to a workplan to explore existing factors, new techniques and system improvements which will remove the need for operational restraints from the Iridium system as of 1st January 2006. These will include, but are not limited to (1) development of an understanding of actual interference effects from Iridium to radio astronomy observations, (2) changes which could be made to the future generation Iridium spacecraft to reduce unwanted emissions into the radio astronomy band 1610.6-1613.8 MHz, and (3) changes which could be made to reduce the susceptibility of radio astronomy observations to interference. The details of the technical areas which will be investigated, and a schedule for these investigations, are described in Annex 1 hereto.
(2)	(a)		In accordance with the Framework Agreement, each of the Parties may communicate to the other party the desire to enter into negotiations with a view to amend, to revise, and to adapt this Agreement or its update, including the addition of European radio astronomy stations who also wish to accede to this agreement. Any such request shall include an explanation of the reasons for further negotiations, details of specific changes sought, and a proposed date for beginning negotiations. Such a request shall be sent to the other party no earlier than one year after the entering into force of this Agreement or its update. If a request is made, the Parties shall meet in order to negotiate in good faith the requested amendments, revisions and adaptations. The negotiation process will start at a date, which must be agreed within 2 months after the request has been received by the other party.
	(b)		This Agreement shall remain effective until the Parties have reached agreement on an update.
	(c)		Representatives from the CEPT (ECTRA/ERC) may be invited to attend negotiations.
(3)			In case of dispute, §§ 7-9 of the Framework Agreement shall apply.
(4)			This Agreement shall be binding on successors in interest to the Parties.

The persons executing this Agreement hereby certify that they are authorised to sign this document on behalf of their respective organizations, including the organizations that operate the radio astronomy sites mentioned in WHEREAS (7) of this document.

ACCEPTED AND AGREED:

Annex 1

Initial Workplan for Investigation of Iridium/Radio Astronomy Interference Compatibility Improvement

This document is not meant to be exhaustive or restrictive and may be added to in the future as necessary and agreed between the parties.

Introduction

The following document is meant to serve as the starting point for a collaborative work effort between CRAF and Iridium, as called for in the ESF/Iridium Framework Agreement. It is understood between both ESF/CRAF and Iridium that ITU-R Recommendation 769-1, which was used as a basis for establishing the protection for radio astronomy in that Framework Agreement, was not developed with a consideration to non-GSO satellite systems. As such, the Framework Agreement acknowledged that there may be certain existing factors beyond those of Recommendation 769-1, or other additional ways for reducing the susceptibility of radio astronomy observations to interference, or ways to reduce the unwanted emission levels from Iridium satellites that would help to eliminate the effect of Iridium unwanted emissions to radio astronomy. The Framework Agreement calls for the parties to work together to quantify the merit of possibilities before 1 January 2006 and the following document outlines a program for this work. This document is not meant to be exhaustive or restrictive and may be added to in the future as necessary and agreed between the parties.

Initial Areas to be Examined:

a. Existing factors

- Antenna pattern considerations (effect of sidelobe levels below 0 dBi, polarisation effects, main beam, etc.)
- Spectral and statistical nature of the interference (noise-like properties; effect of integration, etc.)

b. Further interference susceptibility reduction techniques

- Possible applications of the blanker (including possible selective use)
- Interference characterisation and subtraction based on Iridium duty cycle and/or measured Iridium intended emissions
- Other techniques as agreed upon by the parties

c. Satellite unwanted emission reduction

- Possible improvements that could be made to next generation Iridium satellites to reduce level of unwanted emissions.

Technical Approach:

a. Existing factors

Objective - to determine the extent to which, and manner in which, real world Iridium interference manifests itself in radio astronomy observation data