Ligado Responds to Iridium Analysis

November 2, 2016–Ligado Networks LLC is responding to a technical study submitted recently by Iridium Communications, Inc., that Iridium says details “the significant risk of harmful interference that would be created by granting Ligado the flexibility to deploy user terminals for a CMRS system in the 1627.5-1637.5 MHz band” (TRDaily, Sept. 2). Ligado says it believes the two companies can reach a resolution on pending issues.

In a filing in IB dockets 12-340 and 11-109 reporting on a meeting with FCC officials, Ligado said that “Iridium’s licensed downlink spectrum in the Big LEO band is allocated for MSS downlinks on a secondary, non-interference basis, and Iridium is licensed to use the band for downlinks on that same basis. Accordingly, Iridium’s downlink operations are not entitled to interference protection from adjacent spectrum users operating under primary allocations, including Ligado.”

Ligado also said that its “ATC operating parameters have been fixed for years, and include operation of an unlimited number of 1 watt ATC user terminals under a specified OOBE mask. Significantly, in the pending License Modification Applications Ligado proposes to significantly reduce the level of its ATC user terminal emissions below its long-authorized parameters.”

The filing also said that “Ligado’s proposed ATC operating parameters are fully consistent with the broader operating environment in the spectrum adjacent to Iridium’s downlinks, which is characterized by millions of MSS mobile earth terminals (‘METs’) authorized to uplink at significantly higher power levels than Ligado’s 0.2 watt ATC terminals. Thus, Ligado’s ATC operating parameters are more protective of Iridium than virtually all of the currently authorized uses of MSS spectrum adjacent to Iridium.”

Ligado also said “that it is committed to working with the Commission and Iridium to identify a reasonable technical solution that would allow both networks to coexist in their adjacent licensed spectrum. Toward that end, Ligado explained that if doing so would enable the prompt grant of the License Modification Applications, Ligado would be willing to consider certain additional reductions to its OOBE levels with respect to Iridium’s downlink spectrum, in addition to the reductions already proposed in Ligado’s above-captioned License Modification Applications.”

Ligado said it “explained that the likelihood of reaching such a resolution would be improved significantly if certain flawed assumptions underlying Iridium’s September 1, 2016 technical showing were adjusted to reflect more accurate, suitable, and typical values, as well as to include certain factors that are typically included by the FCC in analyses such as this one. Copies of the tables Ligado presented showing the effect of these adjustments are being filed with the confidential version of this letter as Attachment A. By taking such considerations into account, Ligado expects a reasonable resolution could be achieved promptly without the need to address a variety of legal issues presented by Iridium’s filings in this proceeding.” – Paul Kirby,

Courtesy TRDaily