GLOBALSTAR and Boeing Coordination

1
GLOBALSTAR and BoeingCoordination

• T. Gergely
• Summer School on Spectrum
• Management and Radio Astronomy
• Green Bank, June 2002

2
Globalstar Coordination-1

• OH observations the band 1610.6-1613.8 MHz made
  at the NRAO sites and Arecibo.
• Globalstar, L.P. operates a mobile satellite
  communications system in the 1610-1621.35 MHz
  band.
• The agreement intends to facilitate sharing the
  band by Radio Astronomy observatories and
  Globalstar network uplinks from airplanes to
  satellites.

3
Globalstar Coordination -2

• Globalstar obligations
• When an airborne mobile Earth station is within
  4.1(? h) km (where h is the aircraft altitude in
  meters) of a radio astronomy site that is making
  observations, the average unwanted emission
  levels at the input port to the transmit antenna
  for any 1 MHz segment in the band 1610.6 - 1613.8
  MHz from the airborne mobile Earth station shall
  not exceed -65 dBW/MHz, with a corresponding
  aircraft underside antenna gain of nominally -10
  dBi or lower gain.
• When an airborne mobile Earth station is within
  4.1(? h) km of a radio astronomy site that is not
  making observations, any licensed Globalstar
  frequency may be used.
• NSF/ Radio astronomers Obligations
• Provide an observation schedule for the band
  1610.6 - 1613.8 MHz for the sites included in the
  MoU, with two weeks advance notice

4
Globalstar CoordinationTimeline

• Nov, 2000 GLOBALSTAR approaches NSF to coordinate
  airborne phone terminals and Proposes maximum
  unwanted emission levels in the 1612 and 1660
  MHz bands
• Jan, 2001 Radio astronomy group (NRAO, NAIC, NSF
  and others) meets with GLOBALSTAR engineers,
  considers and rejects proposal as inadequate.
• March, 2001 GLOBALSTAR simulations, based on
  improved unwanted emission characteristics show
  that new standards protect radio observatories
  from interference, except for 1 hr/day (at all
  US observatories)
• April, 2001 Radio astronomy group decides to
  work on an agreement based on this simulation
• Nov., 2001 Agreement between GLOBALSTAR and NSF
  signed
• Observatories protected during periods of
  observations, except 1 hr. daily (peak GLOBALSTAR
  traffic)
• Radio Observatories must notify GLOBALSTAR of
  their schedules
• Jan - Feb, 2001 GLOBALSTAR declares Ch. 11

5
Boeing (Connexion) Coordination - 1

• The 14.47-14.5 GHz band is allocated to radio
  astronomy on a secondary basis for observations
  of the formaldehyde (H2CO) line.
• The 14.0 - 14.5 GHz band is allocated to the
  mobile-satellite (except aeronautical
  mobile-satellite) service (Earth-to-space) on a
  secondary basis.
• Boeing filed an application with the FCC for
  authority to operate up to eight hundred
  technically identical transmit/receive mobile
  earth stations aboard aircraft to operate in the
  11.7 12.2 ? and 14.0 14.5 GHz ? bands.
• US proposal to remove the restriction placed on
  the aeronautical mobile-satellite service
  (Earth-to-space) at WRC-03,

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Boeing (Connexion) Coordination - 2

• Boeing will
• Cease AES transmissions in the 14.47 - 14.5 GHz
  band, within line-of sight of radio astronomy
  stations listed in Section 2.1, during periods of
  notified radio astronomy observations at the
  site.
• Control the AES transmitters so that the pfd
  levels in the 14.47 14.5 GHz band produced at
  radio astronomy sites by individual AESs, during
  notified periods of observation (see Section
  3.7), does not exceed
• pfd ?182 0.5? for ? lt 10
• pfd ?177 for 10 lt ? lt 90
• ? is the angle of arrival, measured in
  degrees, the pfd is expressed in units of
  dB(W/m2/MHz). (met by reducing power, ceasing
  transmissions, or changing frequencies of AESs
  that would exceed the pfd criteria)
• Respond, as expeditiously as practicable, to an
  NSF request for protection of any site , for
  observations of special transient celestial
  objects (comets, supernovae, and other celestial
  objects of heretofore unknown type) that are not
  anticipated by the schedule of Section 3.7, and
  that may need to be accommodated on shorter
  notice. Requests for such observations are not
  expected to exceed 40 hours per calendar year.

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Boeing (Connexion) Coordination - 3

• NSF will
• Maintain an observation schedule for the band
  14.47 - 14.5 GHz for the sites listed in Section
  2.1 and provide this schedule via both e-mail and
  fax, to the designated CBB point-of-contact
  address listed in Section 5.2 at least one week
  prior to the scheduled observations.
• Provide, through NAIC and NRAO full access to
  CBB representatives to data on interference that
  may be collected during observations that fall
  within the scope of this agreement.
• Coordination agreement signed December, 2001