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The Consumer Electronics Hall of Fame: SiriusXM Satellite Radio System

The first satellite-radio subscription service tried to fix all the problems of terrestrial commercial radio

6 min read
Photo of the SiriusXM Satellite Radio System

The Sirius Satellite Radio receiver.Music From Space: In February 2002, as the Sirius Satellite Radio music service went on line, the company held a demonstration in Denver. A receiver mounted in a BMW X5 was tuned to Sirius’s classic rock channel.Photo: David Zalubowski/AP

Listening to the radio and driving are as inextricably linked as peanut butter and jelly. Even if you’ve never cruised a boulevard with the top down and the radio blaring, you’ve probably heard about how great it is in a Beach Boys song (which you probably heard on the radio while driving in your car).

Even so, right from the beginning, listening to the radio in a car had its frustrations. Satellite radio was conceived as the answer to all the things that were irritating about terrestrial broadcast radio.

Complaint No. 1? Advertisements. Conventional, broadcast radio is ostensibly free, so long as you’re willing to subject yourself to the shouty ads that commercial radio stations survive on. Another irritation: the lack of variety. In most countries, commercial radio is dominated by cheesy pop music along with, in parts of the United States, big pockets of talk shows, country, salsa, or Mexican formats such as banda and mariachi. If you’re into classical, jazz, folk, or indie rock, good luck finding a station. Yet another problem is the relatively limited geographical coverage of most stations. On a long trip, it usually seems like the moment you start warming to a station you’re exiting its coverage map. Furthermore, depending on where you are in the world, the number of stations might be few. Some places are completely out of reach of any signals at all.

Satellite radio, on the other hand, is subscription based, so there are no ads. There are scores of different channels, so there’s something for everybody. Partial to ’80s hair bands? The Grateful Dead? “Emotionally driven alt rock”? There are channels for that. Moreover, every single channel is available everywhere there is service. And if there’s sky above you, you’re going to get a signal.

Those may have been the justifications for creating the Sirius Satellite Radio system, but they weren’t the reason, according to Robert Briskman, one of Sirius Radio’s cofounders.

Briskman’s experience with satellite technology goes way back. He got a job with NASA in 1959, the year after it was founded, and then worked for the Communications Satellite Corp. (Comsat) and after that with Geostar Corp. In 1990, one of Briskman’s friends founded a company to compete with cable TV providers. The startup planned to broadcast residential TV services directly from an orbital satellite. Briskman offered his technical expertise.

“I was helping Eddy Hartenstein bring DirecTV to the home, and I suggested adding radio channels to the video channels,” Briskman told IEEE Spectrum. “He said, ‘You know, Rob, people at home look at television, and they listen to radio in the car.’ And I said, ‘You’re right, Eddy, why don’t we do it in the car?’ So he said, ‘That’s technically impossible.’ Those were fighting words to me.”

Sirius cofounder Robert Briskman (center) met Bob Prevaux (left), of satellite builder Space Systems/Loral, and Ted Sitek, of International Launch Services, four days before launch.Ready for Liftoff: The first rocket carrying a Sirius satellite into orbit was launched on 5 September 2000. Four days before launch, Sirius cofounder Robert Briskman (center) met Bob Prevaux (left), of satellite builder Space Systems/Loral, and Ted Sitek, of International Launch Services.Photo: Karl Ronstrom/Reuters

Satellite communication is contingent on maintaining line of sight (LOS) between satellite and receiver. What made satellite radio seem impossible was that vehicles were inevitably going to pass under bridges, drive under tree canopies or into parking garages, enter tunnels, or become isolated in deep canyons of the natural or urban variety.

The challenge facing Briskman was to design satellites and complementary receivers that would somehow maintain LOS as much as possible. If you were to drive into an underground garage and park, the signal would be lost, and nothing could be done about that. But if LOS was lost only briefly, there had to be some way to make sure the receiver could keep on playing until it could pick up the signal again.

Briskman, an IEEE Life Fellow, says it took him seven or eight years and at least five patents’ worth of technology to make the impossible a reality.

A big part of the solution to maintaining a LOS connection between receiver and satellite was satellite diversity. “It just means putting two satellites up there radiating the same signal, but you put them in different parts of the sky. If the car is blocked from one satellite, it hopefully has a clear line of sight to the other,” Briskman explains.

Graph showing the likelihood of a U.S. resident older than age 13 listening to satellite radio rather than conventional broadcast radio in a car.Who’s Listening: The likelihood of a U.S. resident older than age 13 listening to satellite radio rather than conventional broadcast radio in a car goes up sharply with the newness of the car.Image: Edison Research

In cities with tall buildings, the satellites are supplemented by terrestrial repeaters, land-based antennas that beam signals directly into urban canyons. Those measures meant motorists listening to Sirius were almost always going to get a signal, but “almost always” wouldn’t be good enough. There are hundreds of thousands of underpasses in the United States alone, Briskman noted, and going under any one of them could block both satellites.

“The solution to that was another patent, for satellite-time diversity,” Briskman says. “It simply means having two satellites radiating the same signal, but we delay one for, say, roughly 5 seconds.”

The receiver contains a 5-second buffer, so that if the satellites are blocked, the receiver plays out the buffered data. If you’re out of sight of a satellite for more than 5 seconds, you get an outage, but 5 seconds turned out to be enough to get most Sirius subscribers through most underpasses without program interruption.

The receiver is where incoming signals are decoded and decrypted. The Sirius radio is unusual, Briskman says, because it actually has three independent receivers, one each for the two satellites and one for terrestrial repeaters. To deal with three separate receivers, he devised what he called a maximal-ratio combiner. If there are two or three strong signals from the receivers, this circuit puts them in phase and—as the name suggests—combines them. Conversely, if one or two of the signals is bad, it suppresses them.

And the Sirius radio actually comprises two separate units. There’s the first, the one with the receivers, in the vehicle cabin. That’s the part that looks like a typical dashboard radio with a display screen. The other is mounted on the roof or the trunk. It holds the antenna and a low-noise receiver. It takes the signals coming in from the satellites (at slightly different frequencies in the 2300-megahertz band), amplifies them, downconverts them to around 75 MHz, and runs them in to the first unit in the main cabin.

The omnidirectional antenna is fairly small, about 30 millimeters wide, or roughly the size of a U.S. half-dollar coin. Briskman is to this day exasperated that automakers typically insist on packaging his satellite radio antenna with a GPS antenna, which makes the combined antenna unit much bigger than he would like.

SiriusXM Radio Satellite Control Room.Mission Control: In the early 2000s, Sirius controlled its network of three satellites from a control room in New York City.Photo: SiriusXM

Briskman recalls that the implementation of both the satellites and the radio receivers went smoothly. The part of the development that was most taxing and required the most iterations was designing the user interface, a process exacerbated by every different carmaker having different notions of how it should work. “You wouldn’t think you’d have to spend a lot of time on something like that, but we had to. It was worthwhile, though, because the customers appreciated the ease with which you could operate the radio,” he says.

In those heady early days, Sirius had a rival, called XM. Sirius was the first to secure a broadcast license, but XM beat it to the market, going live in September of 2001. Sirius began broadcasting in February of 2002. XM originally got placement with GM, Honda, and Toyota. Meanwhile, BMW, Chrysler, and Ford signed on with Sirius.

The satellite radio market was tough, however. XM would eventually file for Chapter 11 bankruptcy protection. The two companies argued that the only way for both to survive was to merge, and they got permission from regulatory authorities to do so in 2008. Since the merger, the combination has had enough subscribers to remain profitable.

SiriusXM kept improving its technology. The chipset in Sirius’s original radio was a two-IC set, with the chips manufactured using 160-nanometer design rules. The company reduced that pair to one chip at 130 nm in 2004. The postmerger entity kept at it; in 2014 the chip was scaled down again to 40 nm, Briskman notes.

Hartenstein was named chairman of the XM half of the company in 2009; he remains a board member of the combined SiriusXM. Briskman still cruises the highway in his BMW with the top down (“I’m a convertible guy”) blasting Siriusly Sinatra (Ch. 71) and ’40s Junction (Ch. 73). SiriusXM radios are now installed in three-quarters of all automobiles manufactured around the world.

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Interview: Boston Dynamics on Weaponized Robots Letter

Manufacturers’ initiative pledges no militarized robots for non-military purposes

8 min read
Boston Dynamics spot robot set against a mocha-colored background containing logos of several robotics companies and the text of the open-letter against weaponized robotics
IEEE Spectrum

Yesterday, six companies that build or support sophisticated mobile robots (led by Boston Dynamics) published an open letter to the robotics community and industry pledging to not weaponize their general purpose robots. Along with Agility Robotics, ANYbotics, Clearpath Robotics, Open Robotics, and Unitree, Boston Dynamics’ letter seeks to ensure that its robots are used safely and ethically, in a way that helps rather than harms.

Boston Dynamics, and others, find themselves in an increasingly difficult position. These companies are striving to make useful, general-purpose robots, and that means making them useful for anything—even things that they should not be used for. There have been a bunch of high-profile examples of robot misuse recently (that we’re not going to link to), and the companies building the robots being misused have taken it personally—as they should, because those misused robots are very easy to identify. Plus any misperceptions that these misused robots could be autonomous (though they aren’t) makes an implied false connection between the actions of the robot and the ethics of the company.

The letter is just one step, and not the first for any of these companies, towards friendlier, safer robots. But it’s going to take a lot of difficult, complicated steps, and there isn’t even an obvious path forward: as we heard from many of these folks a couple of years ago, it’s hard to maintain responsibility for robots out in the world.

With this complexity in mind, we spoke with Brendan Schulman, Vice President of Policy & Government Relations at Boston Dynamics, to better understand what this letter means.

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Digital Resurrection Brings Star Trek Back to the Future

Visual effects involving deceased actors are increasingly commonplace

3 min read
5 scenes from Star Trek episodes

A montage of scenes from the Roddenberry Archive's efforts to preserve Star Trek.

OTOY/The Roddenberry Archive

The bridge of the original U.S.S. Enterprise could soon be a place you can visit—complete with some of the original cast.

Visual effects that include virtual “performances” by deceased actors, or that drastically de-age those still alive, are becoming commonplace. Rogue One: A Star Wars Story famously used such effects to replicate the late Peter Cushing’s performance as Grand Moff Tarkin. Now, the Roddenberry Archive is using similar effects to give audiences a like-new performance of Leonard Nimoy as Spock—if only inside the virtual world of a video game.

“The kid inside me had always dreamed of being Spock,” says actor Lawrence Selleck, who performs as Spock in the Roddenberry Archive’s restoration. “And now, suddenly, here I am with the Roddenberry Foundation putting on the best set of ears you can possibly imagine.”

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Get the Rohde & Schwarz EMI White Paper

Learn how to measure and reduce common mode electromagnetic interference (EMI) in electric drive installations

1 min read
Rohde & Schwarz

Nowadays, electric machines are often driven by power electronic converters. Even though the use of converters brings with it a variety of advantages, common mode (CM) signals are a frequent problem in many installations. Common mode voltages induced by the converter drive common mode currents damage the motor bearings over time and significantly reduce the lifetime of the drive.

Download this free whitepaper now!

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