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STUDY CONTEXT. Directed by the President Multiple Bands Under Consideration in U.S. 806 - 960 MHz; 1710 - 1885 MHz; 2500 - 2690 MHz DoD focus is 1755-1850 MHz Provide the Use, Cost and Operational Impacts and Trade-offs Scrutinized by NTIA, OMB and FCC Released to the Public.
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1. DoD Interim ReportTechnical Feasibility of Accommodating IMT-2000Within the 1755-1850 MHz Band Mike Williams
Joint Spectrum Center
Senior Engineer
1 December 2000
(410) 293-2681
williamsm@jsc.mil
2. STUDY CONTEXT
3. DOD IMT-2000 STUDY PLAN STRUCTURE
4. DoD IMT-2000 WORKING GROUPS
5. STUDY PURPOSE
6. TECHNICAL APPROACH Identify major incumbent DoD systems
Identify principal DoD analysis factors
Tech parameters, including interference thresholds
Operational scenarios
Determine IMT-2000 analysis factors
Perform 2-way interference analysis for different sharing/segmentation options
Assess results
7. MAJOR DOD SYSTEMS OPERATING IN 1755 - 1850 MHz
8. TECHNICAL APPROACHINTERFERENCE ANALYSIS Antenna coupling
Mainbeam-to-mainbeam, mainbeam-to-sidelobe
Path loss
Terrain dependent for fixed, known locations
Smooth earth mode for transportables, mobiles
Considered frequency dependent rejection
Many-to-one for aggregate IMT-2000 envir
To spaceborne, airborne receivers
One-to-one for terrestrial situations
Separation distance to prevent interference
9. SUMMARY OF INTERIM RESULTS Full band sharing appears very difficult
Substantial separation distances required for co-tuned operation
Over 100 km for terrestrial systems
Over 400 km for airborne systems
SGLS receivers may be degraded by 2006
Segmentation plans will require access to additional spectrum in a comparable band
Loss of channels for radios and control links
Loss of links for ACTS, SGLS
Vacating band will require replacement spectrum
10. MITIGATION CONSIDERATIONS Examine possible mitigation options - DoD
Antenna relocation, shrouding, radiation fences
Sharing of event scheduling
Limitations on training locations and operations
Must maintain full operational capability
Examine possible mitigation options - IMT
Selected antenna orientations
“Listen-before-transmit” capability
Dynamic, event-dependent frequency management
11. REMAINING EFFORTS Gather and characterize operational impacts for each option
Determine cost impacts associated with sharing/vacating
Complete technical assessments including other systems
Consolidate final report
Technical, operational, cost
Coordinate final report within DoD