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Metapath Software International, Inc. 3G Spectrum Allocation Options: The Technical Implications National Spectrum Managers Association Conference. May 23, 2001 George Harter Director of Broadband Engineering. Presentation Overview.
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Metapath Software International, Inc. 3G Spectrum Allocation Options: The Technical ImplicationsNational Spectrum Managers Association Conference May 23, 2001 George Harter Director of Broadband Engineering
Presentation Overview • Discussion of the implications of sharing the same frequencies or adjacent frequencies between the MDS/ITFS service and 3G • Review of global 3G allocations • Review of the MDS/ITFS spectrum allocations and industry applications deployed in the band • Interference protection requirements for MDS/ITFS • Sharing analyses
3G Global Allocations • WRC-92 identified 1885 - 2025 MHz and 2110 - 2200 MHz as possible bands for 3G use. • WRC-2000 further identified 806 - 960 MHz, 1710 - 1885 MHz and 2500 - 2690 MHz • Resolution stating some countries may use 698 - 806 MHz and 2300-2400 MHz • Domestically • 806 - 960 MHz Cellular/SMR/Paging • 1755 - 1850 MHz Primarily DoD • 2110 - 2150 MHz Available • 2150 - 2162 MHz/ MDS • 2500 - 2690 MHz MDS/ITFS • 2165 - 2200 MHz MSS
MDS/ITFS • MDS - • Established as an analog television service • Estimated 750,000 subs at end of 2000 • In 1996 FCC approved digital modulations (QAM/VSB) • Digital television services launched in several markets • In 1998 FCC issued first R&O approving two-way data transmissions • In August 2000 first FCC filing window for two-way systems and 2,267 applications were filed covering in excess of 275 markets
MDS/ITFS • ITFS - • Historically analog television service • Distance learning • Interactive classroom • Now providing high speed Internet access • Tightly linked to MDS for technical and financial support
MDS/ITFS Interference Protection Requirements • FCC rules require: • 45 dB co-channel protection • 0 dB adjacent channel protection • -73 dBW/m2 at BTA boundaries • Protection of noise floor for two-way hubs • Aggregation of power from multiple co- or adjacent radiators
Critical Issues • Frequency sharing between MDS/ITFS and 3G services is impossible • Desired coverage areas are the same • Interference levels restrict system operation to unusable levels • Existing MDS/ITFS systems are widespread • Splitting the frequency band between MDS/ITFS and 3G services is impossible • Capacity requirements of MDS/ITFS services will utilize entire available bandwidth
Reasons for Severe Interference • MDS/ITFS receivers require high degrees of sensitivity for analog television and high order digital modulation • Practical receive antennas do not have sufficient isolation to eliminate the 3G interference • The interference environment is heavily encumbered by existing MDS/ITFS operators • High degrees of frequency reuse will be required for capacity demands and thus the interference environment will be even further strained
MDS/ITFS System Architectures • Analog Television • Supercell (35 mile radius), single tx site, high tx AMSL • 100-1000 Watts EIRP, typical • 12-27 dBi receive antennas • High carrier-to-noise(interference) - 45 dB • Digital Television • Same as analog television • Carrier-to-noise requirement is less from a practical standpoint • Digital Data • Cellular, multiple transmit sites, lower tx AMSL • 10-1000 Watts EIRP • Same receive antennas • Carrier-to-noise dependent on modulation density • High order modulation densities utilized
Interference to MDS/ITFS Systems • Technique is to show interference from typical system configurations and then calculate separation distance to cure interference • Typical MDS/ITFS system: • Analog/Digital TV - 300’ AMSL Tx Ant Hgt, 100 watts EIRP, 12 dBi rx ant, 35 mile service area • Digital Data - 100’ AMSL Tx Ant Hgt, 100 watts EIRP, 12 dBi rx ant, 15 mile service area • Typical 3G Hub system: • 100 watts EIRP in 4.5 MHz bandwidth, 100’ AMSL Tx Ant Hgt
Required Separation to Eliminate Interference ** Radio horizon will limit separation