IEEE Spectrum is the flagship publication of the IEEE — the world’s largest professional organization devoted to engineering and applied sciences. Our articles, podcasts, and infographics inform our readers about developments in technology, engineering, and science.
Enjoy more free content and benefits by creating an account
Saving articles to read later requires an IEEE Spectrum account
The Institute content is only available for members
Downloading full PDF issues is exclusive for IEEE Members
Downloading this e-book is exclusive for IEEE Members
's Digital Edition is exclusive for IEEE Members
Following topics is a feature exclusive for IEEE Members
Adding your response to an article requires an IEEE Spectrum account
Create an account to access more content and features on
, including the ability to save articles to read later, download Spectrum Collections, and participate in
conversations with readers and editors. For more exclusive content and features, consider
Join the world’s largest professional organization devoted to engineering and applied sciences and get access to
all of Spectrum’s articles, archives, PDF downloads, and other benefits.
Learn more →
Join the world’s largest professional organization devoted to engineering and applied sciences and get access to this e-book plus all of IEEE Spectrum’s articles, archives, PDF downloads, and other benefits.
Learn more →
In the face of concerted industry opposition, the Federal Communications Commission (FCC) has given the go-ahead for a controversial smartphone accessory that uses microwaves to send text messages and email via geostationary satellites.
Startup Higher Ground now has permission to deploy up to 50,000 SatPaq devices across the United States, promising isolated communities, hikers, and farmers a cheap, reliable messaging service far from cellphone towers. However, it is a move that some telecoms companies think could also interfere with their services, interrupt life-saving emergency calls and even cause outages nationwide. The roll-out will be a key test of the FCC’s ability to manage spectrum sharing, an innovation it is counting on to enable future 5G wireless and Internet of Things technologies.
The SatPaq devices, first revealed in Spectrum last year, connect to a smartphone messaging app via Bluetooth. The device uses a flip-up antenna that communicates with Intelsat Galaxy satellites in geostationary orbits. These are nearly 50 times further out than the Iridium satellites used by today’s satphones, so the SatPaq needs a powerful signal to connect.
“If this type of application is granted, the FCC itself becomes irrelevant”
It’s that strong signal—smack in the middle of the C-band microwave spectrum used for voice and data communications in rural areas and for national networks—that has many telecoms companies worried. In a submission to the FCC, CenturyLink called Higher Grounds’ plans “a recipe for disaster” and a “potential interference to each and every…link of the [microwave] network throughout the country.”
Its concerns were echoed by a dozen telecoms industry bodies and cities and states that rely heavily on point-to-point microwave stations for communications and emergency services. The state of Hawaii even wrote, “If this type of application is granted, the FCC itself becomes irrelevant. Commercial entities can simply do whatever pleases themselves.”
For its part, Higher Ground claims a robust system of ‘self-coordination’ that makes the chance of interference almost negligible. The SatPaq app starts by comparing the phone’s GPS coordinates with a database of the locations of all the terrestrial microwave stations in the country. It then selects a non-interfering frequency within its 5925 to 6425 MHz uplink band.
“We…find that Higher Ground’s proposed system and operations…would further the Commission’s interest in ensuring the highest public benefit is derived from this finite spectrum resource”
The app then uses the phone’s compass to ensure that the flip-up antenna is pointed directly at the satellite, and not towards a fixed station. If the system cannot find a safe combination of frequency and direction, it will not transmit. When the SatPaq does connect to the satellite, it will download any changes to its station database before transmitting its own data.
Last summer, Higher Ground conducted outdoor demonstrations of a live SatPaq embedded in a smartphone case to FCC officials and some of the telecoms companies, showing both the interference mitigation technology and the messaging service in action.
On 18 January, just 48 hours before the start of the new Presidential administration, the FCC ruled in Higher Ground’s favor. “We…find that Higher Ground’s proposed system and operations…would further the Commission’s interest in ensuring the highest public benefit is derived from this finite spectrum resource,” wrote the Commissioners. “We [also] find that Higher Ground has demonstrated that its proposed system should prevent or minimize the risk of harmful interference to [fixed service] operators.”
The SatPaq attachment uses an antenna on the back to reach geostationary satellites.Photo: Higher Ground
But the FCC did place conditions on Higher Ground’s operations. The company had to accept that existing microwave stations might interfere with its new messaging service, and is required to maintain remote control of all the SatPaqs in the country. If any interference comes to light, Higher Ground must be able to immediately override or shut down any or all interfering SatPaqs. The company also has to keep logs of every single SatPaq transmission for at least a year, and make that data available to the FCC and fixed service operators on request. Higher Ground also has to update its database of terrestrial microwave stations every day.
Finally, the FCC noted that “a cautious approach is warranted, considering that a self-coordination system like Higher Ground's does not have a track record of wide-scale, generalized deployment.” For the first year following authorization, Higher Ground can deploy only 5000 SatPaqs, and the FCC reserves the right to shut them down if they cause harmful interference.
“This is a prudent move for a unique technology,” says Steve Crowley, a consulting wireless engineer. “The phased rollout is an additional measure in case of unintended consequences. It’s easier to get a handle on 5,000 radios than 50,000.”
But Higher Ground’s battles may not be over just yet. The Enterprise Wireless Alliance, a national trade association for business wireless users, is considering filing a last-ditch appeal.
“At its core, this is an engineering matter and I think those engineering matters have been resolved to a reasonable level,” says Crowley. “But the Order was issued just before the start of the current FCC and only one of its three signers holds the same position as they did on January 18. A petitioner whose arguments didn’t prevail with the previous FCC might try again with this one.”
Higher Ground declined to comment on the FCC Order or any plans it might have to start selling SatPaqs. Its website, which previously suggested that SatPaqs would sell for US $139, with pay-as-you-go texts and emails, is currently offline.
Mark Harris is an investigative science and technology reporter based in Seattle, with a particular interest in robotics, transportation, green technologies, and medical devices. He’s on Twitter at @meharris and email at mark(at)meharris(dot)com. Email or DM for Signal number for sensitive/encrypted messaging.