The December 2022 issue of IEEE Spectrum is here!

Close bar

Controversial Satellite-Messaging Startup Higher Ground Cleared for Takeoff

Now telecom companies fear interference from 50,000 SatPaq devices

4 min read
A hiker in a yellow jack looks at her smartphone.
Photo: Getty Images

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.

[shortcode ieee-pullquote quote=""If this type of application is granted, the FCC itself becomes irrelevant"" float="left" expand=1]

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.

[shortcode ieee-pullquote quote=""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"" float="right" expand=1]

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.”

A hand holding a Samsung smartphone with a Higher Grounds SatPaq attachment, which includes an antenna that sticks out the back.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.

The Conversation (0)

Metamaterials Could Solve One of 6G’s Big Problems

There’s plenty of bandwidth available if we use reconfigurable intelligent surfaces

12 min read
An illustration depicting cellphone users at street level in a city, with wireless signals reaching them via reflecting surfaces.

Ground level in a typical urban canyon, shielded by tall buildings, will be inaccessible to some 6G frequencies. Deft placement of reconfigurable intelligent surfaces [yellow] will enable the signals to pervade these areas.

Chris Philpot

For all the tumultuous revolution in wireless technology over the past several decades, there have been a couple of constants. One is the overcrowding of radio bands, and the other is the move to escape that congestion by exploiting higher and higher frequencies. And today, as engineers roll out 5G and plan for 6G wireless, they find themselves at a crossroads: After years of designing superefficient transmitters and receivers, and of compensating for the signal losses at the end points of a radio channel, they’re beginning to realize that they are approaching the practical limits of transmitter and receiver efficiency. From now on, to get high performance as we go to higher frequencies, we will need to engineer the wireless channel itself. But how can we possibly engineer and control a wireless environment, which is determined by a host of factors, many of them random and therefore unpredictable?

Perhaps the most promising solution, right now, is to use reconfigurable intelligent surfaces. These are planar structures typically ranging in size from about 100 square centimeters to about 5 square meters or more, depending on the frequency and other factors. These surfaces use advanced substances called metamaterials to reflect and refract electromagnetic waves. Thin two-dimensional metamaterials, known as metasurfaces, can be designed to sense the local electromagnetic environment and tune the wave’s key properties, such as its amplitude, phase, and polarization, as the wave is reflected or refracted by the surface. So as the waves fall on such a surface, it can alter the incident waves’ direction so as to strengthen the channel. In fact, these metasurfaces can be programmed to make these changes dynamically, reconfiguring the signal in real time in response to changes in the wireless channel. Think of reconfigurable intelligent surfaces as the next evolution of the repeater concept.

Keep Reading ↓Show less
{"imageShortcodeIds":[]}