Globalstar not interested in Iridium's latest spectrum sharing proposal

Iridium Constellation says it can share additional 1.6 GHz band spectrum without causing harm to Globalstar, but a Globalstar representative says the satellite company is just acting in its own best interests.

In a filing with the FCC, Iridium submitted what it describes as "an elegant solution" to the spectrum conundrum that neither takes spectrum away from Globalstar nor impairs Globalstar's ability to pursue its terrestrial low power service (TLPS) or Big LEO MSS plans.

"The approach outlined below also addresses any lingering concerns about (1) unexpected interference during peak system uses during rare and unpredictable natural or manmade disaster; and, (2) the effects on radioastronomy of Globalstar concentrating its traffic in the lower band channels," Iridium said.

But Globalstar is not interested. "Iridium's most recent filing is just its latest attempt to rearrange the Big LEO L-band to its own advantage. Iridium continues to revise and scale back its demands, apparently realizing that there is no support at the FCC," L. Barbee Ponder IV, general counsel and vice president of regulatory affairs at Globalstar, told FierceWirelessTech in a statement.

In its FCC filing, Iridium says the record shows that Iridium can share additional 1.6 GHz Band spectrum without causing harm to Globalstar. "Since sharing addresses Iridium's spectrum needs, it is not necessary now to pursue a reassignment of spectrum from Globalstar for Iridium's exclusive use. Accordingly, Iridium is proposing to only pursue sharing of the 1616-1618.725 MHz band at this time."

By way of background, Iridium noted that in a May 2014 filing, Iridium requested that the commission designate the 1616-1617.5 MHz portion of the Big LEO MSS band for shared use between Iridium and Globalstar and assign the 1617.5-1618.725 MHz spectrum exclusively to Iridium. Subsequent to that proposal, the FCC's International Bureau held a series of meetings between the Big LEO MSS operators, followed by more filings and engineering analyses. 

"The evidence compiled on the record in this proceeding demonstrates that Globalstar and Iridium currently are sharing heavily used spectrum without Globalstar detecting any Iridium signal, let alone experiencing harmful interference from Iridium; that Iridium can immediately make use of expanded sharing to fulfill existing and future demand for its services; and that the risks of interference, in the unlikely event that it should occur, are borne by Iridium and not Globalstar. "

Therefore, Iridium said it is revising its spectrum proposal, withdrawing its request for additional exclusive 1.6 GHz Big LEO MSS spectrum. Per its current proposal, Iridium and Globalstar would have shared access to the spectrum at 1616-1618.725 MHz, and Iridium's exclusive spectrum assignment at 1618.725-1626.5 MHz would remain unchanged.

According to Iridium, the new proposal takes no spectrum away from Globalstar and does not harm its ability to pursue its TLPS or Big LEO MSS plans. "Moreover, Globalstar would retain its significant spectrum advantage over Iridium, continuing to have access to over 25 MHz of spectrum (nearly 36 MHz, if you count the 2.4 GHz ISM spectrum to which Globalstar seeks access through its TLPS proposal) paired across the 1.6 GHz and 2.4 GHz band, compared to only 10.5 MHz of unpaired spectrum for Iridium (of which more than a quarter will be shared with Globalstar).

Source: Iridium FCC filing

"As Iridium explained previously, the 'power robbing' impact on satellite capacity asserted for the first time by Globalstar in its January 14, 2015 filing, if it exists at all, was explained by Globalstar's consultant to result from a design flaw of Globalstar's system, which receives and repeats the entire Lower Big LEO MSS passband--as such, the problem exists regardless of whether Iridium gets access to additional spectrum, and increased sharing would have no additional impact."

Iridium added that expanded sharing would give Iridium access to an important incremental infusion of additional spectrum, which it could use immediately to improve the capacity, stability and performance of its current generation system and expand the range of advanced voice and data services that will be offered over Iridium NEXT.

Meanwhile, the Entertainment Software Association (ESA), which represents publishers of video games and manufacturers of video game consoles, filed comments in the FCC proceeding that urges the commission to proceed with caution. "The technical record, including Globalstar's demonstration results, does not provide the commission with an adequate basis for adopting the rule changes sought by Globalstar," the ESA said.

Every mainstream game console sold in the United States during the past 10 years uses the 2.4 GHz unlicensed band. Consoles also use Wi-Fi to access the Internet and Bluetooth, or a similar protocol, to transmit gamers' button presses and other inputs from wireless game controllers to the console itself, according to the organization. Even a small amount of latency on either the Wi-Fi or Bluetooth link will diminish a player's gaming experience, and "Globalstar's proposed TLPS service threatens to interfere with these links and thus increase latency," ESA wrote.

Globalstar last week also responded to CableLabs' assertions that last month's tests at the FCC's Technology Experience Center in Washington, D.C., showed interference problems. One of Globalstar's technical experts, Kenneth Zdunek, chief technology officer of Roberson and Associates LLC and a former Motorola networks VP, submitted a written declaration backing the tests that Globalstar conducted and refuting claims made by CableLabs.

Covington, La.-based Globalstar is once again urging the commission to move forward expeditiously to allow it to use TLPS. The company says it would be "bad policy and bad precedent" for the commission to require additional test data for "every potential deployment scenario" that would be possible under the commission's proposed TLPS rules.

For more:
- see this Iridium filing
- see this Globalstar filing
- see this ESA filing

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