Dismissal of Earth Station Modification Applications
On February 22, 2005, the Federal Communications Commission's International Bureau Satellite Division dismissed without prejudice two modification applications filed by Iridium Satellite LLC and Iridium Carrier Services LLC. The actions were taken pursuant to Section 25.112(a)(1) and delegated authority under Section 0.261 of the Commission's rules.
The dismissed filings include application SES-MOD-20040625-00884 (as amended by SES-AMD-20040707-00955) for Mobile-Satellite Service (MSS) earth station E960132, filed June 25, 2004, and application SES-MOD-20041115-01684 for earth station E960622, filed November 15, 2004. Both earth stations are licensed to operate in the 1616-1626.5 MHz L-band to communicate with the Iridium satellite constellation. The proposed modifications sought to add a repeater exchange system intended to enhance coverage in environments lacking line-of-sight between satellites and user handsets.
Power Discrepancies and Underlying Deficiencies
The Satellite Division dismissed the applications as defective due to internal inconsistencies in the reported power levels. In Schedule B of the applications, the maximum Equivalent Isotropically Radiated Power (EIRP) per carrier was reported as 18.5 dBW. However, the total EIRP calculated from the reported 5 Watts total input power at the antenna flange and 0 dBi transmission antenna gain equaled 7.0 dBW, leaving the Commission unable to determine the actual emission power in use.
The Bureau also detailed several critical technical concerns that must be resolved if the applicants choose to refile under Section 1.1109(d) of the Commission's rules.
- Points of Communication: The applications listed satellites on the Permitted List, which is restricted to geostationary satellites operating in the 3700-4200 MHz, 5925-6425 MHz, 11700-12200 MHz, and 14000-14500 MHz bands, conflicting with the earth stations' L-band operations.
- Radionavigation Protection: The provided test report failed to verify compliance with Section 25.216 limits protecting the 1559-1610 MHz Aeronautical Radionavigation-Satellite Service band. The submitted two-tone intermodulation test used a 1627 MHz tone outside the operating passband, placed products outside the protected band, and suffered from insufficient dynamic range.
- Test Power Output: The applications' listed total EIRP of 18.5 dBW implied a 71-Watt transmit power, whereas the test report specified 5 Watts. In addition, test tones were set to -33 dBW (27 dB lower than the expected -6 dBW adjusted level), and the filing did not justify the use of a 9.2% duty cycle or time-averaging assumptions.