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Dynamic Scheduling and Coordina3on Agreements
Andrew Clegg


Coordina3on Agreements
· Agreements nego3ated with other spectrum users to protect radio astronomy observa3ons from poten3ally conflic3ng transmissions · Impacts shared bands or adjacent bands · O@en specified on the basis of one of the following:
­ Geography ­ Time ­ Both geography and 3me


Coordina3on Example (U.S.)
14.47-
14.5 GHz Radio Astronomy (5.149 and US342) FIXED-
SATELLITE (Earth-
to-
space) 14 GHz 14.5 GHz

· 14-
14.5 GHz is used in the U.S. for uplinks to GSO satellites for Internet service from planes, vehicles, and ships · U.S. radio astronomers have executed coordina3on agreements to mi3gate interference to radio astronomy in the 14.47-
14.5 GHz band


14 GHz Coordina3on Agreements
· Aeronau3cal
­ ­ ­ ­ Boeing/Connexion Gogo Panasonic Row44

· Vehicular · Ships
­ L3 ­ RaySat ­ KVH


Observing Schedules
· All of the U.S. 14 GHz coordina3on agreements require radio astronomers to furnish a list of scheduled 14.5 GHz observa3ons upon request · In prac3ce, radio astronomers distribute scheduled observing to respec3ve satellite operators' points-
of-
contact on a monthly basis


Example Language
· NSF/Boeing agreement
­ NSF agrees to:
· 3.7 Maintain an observa3on schedule for the band 14.47 -
14.5 GHz for the sites listed in Sec3on 2.1 and provide this schedule via both e-
mail and fax, to the designated CBB point-
of-
contact address listed in Sec3on 5.2 at least one week prior to the scheduled observa3ons.

· NSF/Gogo agreement
­ NSF agrees to:
· 3.5 Maintain an observa3on schedule for the band 14.47 -
14.5 GHz for the sites listed in Sec3on 2.1 and make this schedule available upon request to the designated Gogo point-
of-
contact listed in Sec3on 5.2.


Dynamic Scheduling
· Radio astronomy community moving to increased use of dynamic scheduling of observa3ons, based on weather and other considera3ons · Dynamic scheduling complicates coordina3on agreements because advance no3ce of observa3ons at specific frequencies is more problema3c


Green Bank Telescope Dynamic Scheduling System


Challenges Going Forward
· Future spectrum sharing of radio astronomy bands (which is likely) will require increasing use of database-
based approaches for no3fying use of radio astronomy bands · Minimum 3mescales of advance no3fica3on will be required to meet the requirements of dynamic spectrum access databases (such as the TVWS and SAS databases in the U.S.) · Database 3mescales have typically been targeted at 24 hour updates, but could be shortened · Real-
3me coordina3on is unlikely at least in the near-
to mid-
term


Opportuni3es Going Forward
· Will provide increasingly dynamic and complex coordina3on agreements allowing beeer protec3ons in shared bands · RA dynamic scheduling systems can be easily modified to provide automated integra3on with dynamic spectrum access databases

­ Efficient opportuni3es for spectrum sharing of RA bands with ac3ve users ­ May allow addi3onal protec3on considera3ons for RA sites outside of RA bands ­ Will bring RA into the modern spectrum world


Near-
term DSS/DSA Integra3on Opportuni3es
· Iridium · TV White Spaces · 14 GHz (including future air-
to-
ground)


Summary
· Dynamic scheduling systems, as isolated en33es, make effec3ve coordina3on agreements virtually impossible to implement · Integra3ng dynamic scheduling systems into evolving dynamic spectrum access databases will be a powerful tool for improving spectrum access and u3liza3on, and will provide for automated coordina3on agreements


Recommenda3ons
· Radio astronomy facili3es should think about the implica3ons of sehng a minimum dynamic scheduling 3me scale that's compa3ble with current developments in dynamic spectrum access databases · The radio astronomy community should work with database providers to understand how dynamic scheduling so@ware could be easily modified to facilitate M2M integra3on
­ Two hours is probably the minimum

­ TVWS database providers are ac3ve in the UK and US