We Need Another Location Technology Like We Need Another Social Network


Rosum, a company that offers a way to use broadcast TV signals to derive location, today said its technology will be used (PDF) in a new chip from mobile TV chip maker Siano. The Alloy chip is aimed at providing location and timing information for femtocells, people and inventory tracking, and local ads via mobile TV. I think it’s an idea that’s doomed to fail because the overall market is too small.

Rosum has been selling the idea of using broadcast TV to determine location for a while. But we already have two methods of measuring location — GPS, which uses a satellite signal and a database, and Wi-Fi triangulation as used by Skyhook. Do we really need a third?

Wi-Fi location information is faster and works better in urban areas where GPS signals have a hard time penetrating. GPS works where there are no Wi-Fi networks, such as in rural areas or along highways. So what does Rosum’s broadcast TV solution have to offer? Rosum says it’s for areas where Wi-Fi networks aren’t able to penetrate, such as deep inside buildings, or where there are a lot of networks that may confuse location, such as in highly urban areas. However, Wi-Fi still seems to work well even in those situations.

There’s also the issue of putting a separate broadcast TV chip inside a device. Wi-Fi chips are already embedded in many handsets and devices, and provide a primary function outside of delivering location. GPS chips are also becoming more common for mobile devices that don’t have Wi-Fi, or that offer navigation. However for many devices, using Wi-Fi alone will suffice.

But Rosum’s primary function is location, and relies on grabbing broadcast TV signals.
So to take advantage of the Rosum solution, a device would have to need a broadcast television signal and not need Wi-Fi or GPS. How often does this happen? I can’t think of a reason to add a broadcast TV signal-detecting chip to a femotcell, but I can see a reason to add Wi-Fi. I can see Rosum winning customers among device-makers wanting to add location to the mobile televisions that will use the Open Mobile Video Coalition’s standard for mobile TV, but that’s a young and small market.

For now, I’m highly skeptical as to Rosum’s chances for making broadcast signals a third source of location information. Yes, location is hot, but between Wi-Fi and GPS, broadcast TV looks more like a third wheel.

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mayo ma

I agree they try to make it seem as if there is a huge demand for indoor GPS, and that the technology actually works. Having worked closely with them, Rosum is just another company trying to create a lot of hype so they can get bought out. They are far from delivering a reliable technology that actually works. Their executive team, ceo, cfo and engineering director, lack the ability to deliver.


A couple points. I just can’t comprehend how TV broadcast signal and a TV tuner can locate a device? How does the technology work? Does it require a special broadcast or regular TV stations?

And as I understand, they pitch this solution at femotcell market. If femtocells have unique identifiers (that it’s a femtocell with a hundred feet radius, not a regular cellular base station), then Google or Skyhook will create a database of femtocell IDs and their locations so that usual devices like smartphones can use that information for location services. It means this solution will greatly enhance the positioning precision indoors and in urban areas without the need to deploy the chip into devices themselves.

So I think any technology that enhances location should be welcome.

Todd Young


We use TV signals as is, without modification, for location. Rosum uses broadcast TV signals, effectively, as super-high-power GPS. We measure the timing of the signals, just like a GPS receiver, and we compute the distance to the emitter (in this case a TV tower instead of a satellite), and then we compute timing, frequency, and location, just like GPS. The difference is that TV and GPS signals are all utilized, the TV signals are 100,000 times the power of GPS, and TV is highly aligned with population – and therefore with urban and indoor environments where GPS performance is problematic. You can read more at the Rosum website, or contact me.



Todd Young

Please allow me clarify the market we are addressing, our place in the location and synchronization technology market – the problem we uniquely solve, dependence on TV tuners, and why this announcement is important.

Market. The market for Alternative Positioning Technologies is booming because of increasing expectations of location technology and the understanding that GPS alone is not enough. With half a billion GPS chips a year on the near horizon and none of them working indoors, this is an enormous market.

Rosum’s place in the Location and Timing Technology Market. There are many location technologies employed in mobile devices today: GPS, A-GPS, Cell tower ID, cell tower triangulation (quite an alphabet soup of different versions of this – E-OTD, U-TDOA, AOA, A-FLT, to name the main ones), WiFi, inertial navigation systems, Bluetooth, RFID, and motion detectors. All provide a solution to part of the problem, but TV provides a unique combination of merits that other technologies cannot match – indoor and urban penetration, robust and reliable infrastructure, and the ability to provide both location and synchronization.

  • Indoor penetration. TV signals are 100,000 times stronger than GPS indoors, so there’s really no comparison between TV and GPS. Where wide-area in-building and urban location coverage is required, TV provides better coverage than WiFi. TV provides coverage across entire metropolitan areas, not just where access points are surveyed and entered into a database. TV will expand location and timing coverage greatly for mobile and fixed devices.

  • Robust and reliable infrastructure. For safety-of-life and security applications such as E911, offender monitoring, first responder location, parolee tracking, stolen asset recovery, and asset tracking, it is simply not an option to rely on a positioning system that is unavailable when the power is out. Broadcast TV is robust even in the worst of disasters.

    “During Katrina, for example, not only did power go out, but cellular networks and the public switched telephone network were also knocked out. Portions of the TV and FM infrastructure stayed on the air, leading to a commendation to the National Association of Broadcasters by President Bush. In the end, the broadcast infrastructure was shown to be robust.” InsideGNSS, October 2006 http://www.insidegnss.com/node/868

Broadcast TV is part of the Emergency Alert System, it employs backup power. It’s public safety obligations are clear. WiFi positioning is a best-effort system, and as Josh points out, it is subject to spoofing.

Further, with the decommissioning of LORAN, broadcast TV is well-positioned to serve as a backup for GPS for critical national infrastructure, for which the main need is synchronization. Which leads us to…

  • Synchronization and Location. With respect to femtocells, one of the greatest challenges for femtocells today is location and synchronization. Location is used for E911, regulatory compliance, spectrum management, pricing control, and other “femtozone” applications such as location-based services and advertising. Synchronization ensures that the femtocell does not interfere with the macro network or with other femtocells. The reason carriers advise customers to wait 60-90 minutes for their femtocell to start up is that getting location and synchronization to the femtocell is difficult with GPS. The challenge of GPS performance and the long start-up time leads to many customer care calls for the carriers. In stark contrast, Rosum ALLOY provides much more reliable and faster start-up, typically three minutes.

Further, indoors, GPS performance can be periodic – satellites fly by the window and go into and out of view, causing the femtocell to lose synchronization. This is called “holdover,” and it drives the need for a pricey oscillator to be used in the femtocell. Rosum ALLOY eliminates the GPS holdover issue – TV signals are 100,000X stronger than GPS and the towers don’t move. By eliminating holdover, ALLOY can utilize a cheaper oscillator. Thus the hybrid TV-GPS solution (which utilizes an A-GPS chip itself) is cost-competitive with stand-alone A-GPS solutions.

WiFi cannot provide synchronization, and it is hard to imagine that carriers will allow the use of WiFi positioning for regulatory compliance and E911 call routing. Not even Skype thinks this is a good idea… http://www.skype.com/allfeatures/no911/ ALLOY TV+GPS provides reliable location, timing, and a quick start-up to improve the customer and carrier experience with femtocells.
TV Tuners.

You rightly pointed out that we need a TV tuner as part of our solution, and that TV tuner deployment into handsets in the US is a nascent market. There are both TV tuner-enabled devices and devices that do not have TV tuners. Regarding the availability of TV tuners in mobile devices, Mobile TV deployments around the global are driving TV tuners into mobile devices. In Japan and Korea, the majority of handsets shipped have broadcast TV viewing. Further, PND device makers are adding TV viewing as a feature. http://www.gearlog.com/2009/12/garmin_mio_navigon_to_add_mobi.php The new Mobile Digital standard in the U.S. also provides the platform for new free-to-air and premium-service mobile TV viewing. Mobile TV chips are being added to handsets and laptops to support TV viewing. Rosum and Siano are showing that the growth in mobile TV can empower better indoor location for mobile devices. This is much like the WiFi model – use the on-board chip to provide an additional capability.

Femtocells and tracking devices do not inherently have a need for a TV tuner, but they do have a need for reliable, in-building location, and even vendors who are employing GPS and WiFi today are looking at ways to integrate Rosum purely for our enhanced location capability.

Why Rosum is Important – a Dynamic Hybrid Market. Rosum advocates a hybrid location strategy. TV-positioning does not require that GPS and WiFi are not used. In fact, ALLOY is a hybrid TV-GPS solution, utilizing all available GPS and TV signals so that it seamlessly transitions from GPS to hybrid to TV mode as the user moves from outdoor areas to deep indoor areas. Many location solutions, including Skyhook’s, employ this strategy – using a variety of “signals of opportunity” to produce the best position fix possible. Your CDMA handset employs this strategy today, using A-GPS, cell tower triangulation and cell tower ID together to work across more environments. Rosum takes this concept of hybrid location further by using the TV and GPS components for cross-aiding. As an example, Rosum can use TV to provide extremely accurate frequency to the GPS chip so that GPS signal acquisition is much faster. Thus the GPS works better when combined with TV, and the number of difficult environments in which TV-GPS provides reliable location is expanded.

This is clearly the future (and present) of location technology – incorporate multi-sensor, multi-function chips into mobile devices and use all available signals, integrate them together as raw data, and produce the best location possible. It is for this reason – that we are integrating two separate functions into a single chip – that the ALLOY announcement is so important. It is part of a larger trend in mobile technologies and location technologies alike.

I greatly appreciate the opportunity to have this dialogue with you. We have additional releases coming in the next few months, so “stay tuned”.

Todd Young
VP Business Development
Rosum Corporation

Rosum is a World Economic Forum Technology Pioneer, a Frost & Sullivan Technology of the Year awardee, and a Red Herring 100 Technology company.

Sanjay Maharaj

I agree with you analysis, wi-fi, GPS are the in thing for location technology especially with wi0fi and how things are readily moving to smartphones, I really do not see a neeed and use for a third


I agree with the general point that WiFi plus GPS will suffice for most situations. It’s worth noting, though, that in indoor settings, where GPS is unreliable, relying on WiFi may be good enough for most applications but still insufficient for femtocells, where there is a legal requirement about location.

I think even SkyHook would admit that devices using its technology can be fooled — it’s possible for a user to add a router to the SkyHook database and lie about its location, and of course it’s always possible to have one or more devices spoof the MAC addresses of devices in distant locations. Together, these techniques could “convince” a femtocell that it was operating in a licensed location when, in fact, it might be thousands of miles away (and interfering with another operator’s licensed spectrum). Rosum’s approach both works indoors and is, I’d guess, more resistant to spoofing, so some cell operators might prefer it to using SkyHook.

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