Proposed Wi-Fi Channel Rattles Band Users Who Claim 2.4 GHz Spectrum Interference

By Brandon Ross

April 24 — Globalstar Inc. technology, which would create a fourth Wi-Fi channel and potentially increase Wi-Fi speeds nationwide, interferes too much with existing devices, Bluetooth SIG, Inc., and Wi-Fi industry groups are telling the Federal Communications Commission.

The company, which provides mobile voice and data communications services via satellite, wants to create its terrestrial low-power service (TLPS) in the 2.4 gigahertz (GHz) spectrum band. Globalstar says its TLPS would increase Wi-Fi capacity by one-third.

“We’re talking spectrum that consumers can begin to see benefits from within weeks, instead of a decade” as with AWS-3 spectrum, Barbee Ponder, Globalstar's vice president of regulatory affairs and general counsel, told Bloomberg BNA.

The FCC adopted a notice of proposed rulemaking (IB Docket No. 13-213) on Globalstar's TLPS plan on Nov. 1, 2013. The company conducted a technical demonstration at the FCC Office of Engineering and Technology (OET) in early March that resulted in the flurry of objections in filings from incumbent users of the band such as Bluetooth and Google Inc., and industry groups such as the National Cable and Telecommunications Association (NCTA).

The company and its critics describe what appear to be mutually exclusive test results from that demonstration in comment filings—saying that conditions were inconclusive, weren't representative of real world conditions and even that the setting up or conduct of the tests were unfair.

“The Commission will consider the results in determining what next steps may be appropriate in the pending rulemaking,” an FCC official who requested anonymity told Bloomberg BNA in an April 23 e-mail.

Harmful Intrusion Seen

Spectrum bands are the digital highways through which wireless broadband signals reach devices. With an ever-increasing number of Wi-Fi users and a rapidly growing number of wirelessly connected devices, the FCC is trying to maximize the national use of a finite amount of spectrum.

Because Wi-Fi signals primarily travel along three spectrum bands—or Wi-Fi channels—that don't overlap in the 2.4 GHz spectrum band, the promise of a fourth Wi-Fi channel is that it might reduce congestion in the existing bands.

The creation of the new channel 14 is what Globalstar is pitching with its TLPS. However, since the FCC put out its NPRM, critics have been vocal—and increasingly so since the March demonstration.

For Bluetooth devices in the U.S., “the 10 MHz at the top of the 2.4 GHz unlicensed band—the frequencies that Globalstar has petitioned to occupy—is the only portion of that band that is reliably free from interference,” the Entertainment Software Association (ESA) said.

“Right from the get-go we’ve said that there’s going to be interference from this technology that Globalstar is proposing,” Mark Powell, executive vice president of Bluetooth, told Bloomberg BNA in an April 10 interview about the demonstration. The TLPS “is going to [negatively] affect hundreds of millions of products just in the United States,” he said. “With a number of [the devices] being more critical health monitoring products, we’re going to naturally be more concerned about interference,” Powell, whose group has some 26,000 worldwide members, said.

Globalstar's TLPS would add Wi-Fi capacity, but “it’s like they added a fourth lane on the freeway,” Greg Gerst, of Gerst Capital LLC told Bloomberg BNA in an April 20 interview. What Globalstar doesn't “say is that the fourth lane was a bike lane, so now they’re going to run over all the bikers on the freeway.” Gerst runs a hedge fund, Gerst Capital LLC. He said he is short-selling Globalstar's stock, so he has been very active in the Globalstar TLPS FCC proceeding.

While Bluetooth has asked the agency to quickly reject the proposal, others say that, at a minimum, more testing is needed.

Globalstar: Demonstrated Potential

Globalstar regards the March demonstration at the FCC as a proof-of-concept.

For example, Globalstar says the testing showed a 40 percent increase in Wi-Fi speed to wireless devices, owing to the reduced congestion on the Industrial, Scientific, Medical (ISM) band with the three main channels—1, 6 and 11.

In tests that showed interference, Globalstar says that conditions were set up unfairly.

“Due to the close physical proximity of the TLPS access points to the client devices, the received power levels at those devices were atypically high and more likely to result in a detrimental impact to other unlicensed services than what would occur in the real world,” Globalstar's April 6 filing said.

When asked about criticism from an April 2 Google filing on the power levels of the devices used in the demonstrations, Globalstar's Ponder said April 8: “Contrary to Google’s statements, running at max power within the confines of the FCC’s technology experience center would not have represented a real world deployment. The power limits were part of a decision that was completely consistent with what OET wanted to see—a real world demonstration of the TLPS opportunity.”

“It would have been absurd to test at that [40 times power] level,” Ponder said. Globalstar's technology is aimed at operating in indoor areas, he said. Generally such high power levels would be reserved for outdoor deployment.

“Our demonstration showed a 40 percent increase in aggregate throughput (speed) for the network when TLPS was made available,” Ponder said.

Bluetooth Sees Interference

In order for spectrum users operating on adjacent spectrum bands to avoid interfering with one another, so-called guard bands are put in place. The bands are the last few megahertz at the top or bottom of a spectrum band, in which users stop transmission of signals before they reach the end of a given band's limits. This reduces the possibility of interfering with signals on adjacent bands, which is crucial to allowing networks to operate smoothly, Bluetooth's Powell told Bloomberg BNA.

Globalstar's TLPS wouldn't observe those guard band practices and would produce too much interference with the existing unlicensed users of the 2.4 GHz band, TLPS critics told the FCC.

Powell's bottom line was: “We think it’s unfair that we have to operate under one set of rules while someone else [Globalstar] gets to operate under a different set of rules.”

Whatever improvements to Wi-Fi speeds might be gained from TLPS approval, Bluetooth said, the demonstration results confirmed that interference increased in some cases from 10 percent to 20 percent. That 20 percent interference rate isn't correctable, he told Bloomberg BNA.

There was “some very obvious stacking of the deck by Globalstar” during the FCC demonstration, Powell said. “Notwithstanding that stacking of the deck, we were still able to show that there was interference.”

Bluetooth's members go to great lengths and spend a lot of money to comply with FCC non-interference rules, Powell said.

Looking Ahead

“We know of no commitment by Globalstar to limit itself to 802.11 technology,” CableLabs, a cable-industry consortium, said in an April 14 FCC filing. “It is possible that Globalstar may deploy other technologies, such as LTE, which… would significantly change the parameters of measurement and potential impact to ISM.” CableLabs conducted a set of tests of the TLPS at the March demonstration.

CableLabs said its measurements showed a negative impact on Wi-Fi, varying in impact depending on the equipment used, adding that the tests didn't give a complete assessment of the impact of TLPS on Wi-Fi performance.

Gamers Depend on 2.4 GHz Band

ESA said that the impact of Globalstar's TLPS on the tens of millions of video game consoles in the U.S. could be significant.

“Every mainstream [game] console sold in the United States during the past ten years uses the 2.4 GHz unlicensed band extensively,” ESA said in an FCC filing posted April 21. “Consoles use Wi-Fi network connectivity to access the Internet but also use Bluetooth (or a similar protocol) to transmit gamers’ button presses and other inputs from wireless game controllers to the console itself.”

“Even a small amount of additional latency or “lag” on either the Wi-Fi or Bluetooth link will diminish the consumer’s gaming experience and will lead to significant frustration,” ESA's filing said. “GlobalStar’s proposed TLPS service threatens to interfere with these links and thus increase latency.”

Promise of TLPS

The TLPS can bring spectrum benefits to consumers relatively quickly, Globalstar's Ponder told Bloomberg BNA.

If approved soon, “these commissioners will still be sitting on the commission when consumers begin to receive the benefits of this additional spectrum,” Ponder said.

Ponder also said that Globalstar committed to a number of a public interest conditions if it is allowed to launch its TLPS.

“What we committed to do was provide 20,000 TLPS access points to schools and other charitable institutions to further the government’s broadband deployment goals,” Ponder said. “We’ve also committed to provide our mobile satellite services to our customers free of charge in any federally declared disaster zone.”

“I think that there is a serious focus at the FCC on our proceeding,” Ponder said. “We are quite hopeful that the FCC will take action in the very near term.”

But a decision may come later rather than sooner, Gerst said.

“I would eat my socks if this [TLPS] gets approved anytime in the next few months,” Gerst told Bloomberg BNA based on his meetings with FCC staff regarding the TLPS proceeding. “I would be surprised if [the FCC] make[s] a decision anytime in 2015.”

To contact the reporter on this story: Brandon Ross in Washington at

To contact the editor responsible for this story: Heather Rothman at

To see the FCC notice of proposed rulemaking, go to:;ECFSSESSION=8VtYV3KbQtkcf7QnTWMhwxz QdTQgR4TGb11kWp1DTGVyltY9bWxJ!-1420975216!-1816268914?id=6017474683.

To see the FCC staff report on the Globalstar demonstration:

To see comments from CableLabs:

Comments from Globalstar are available at: