LTE in the WiFi Spectrum

Apparently T-Mobile is getting ready to launch an LTE service in the unlicensed WiFi spectrum.

I’ve written a fair bit here at AVC over the years about the fact that unlicensed spectrum provides a path for way more innovation than licensed spectrum. I am a big fan of unlicensed spectrum and I believe that the secret to more mobile bandwidth in the coming years is more unlicensed spectrum and less licensed spectrum. I believe that auctioning off the most valuable and useful spectrum to the highest bidders, who often warehouse and under utilize it, is bad policy.

This move by T-Mobile is very interesting to me in a number of dimensions:

1) Can LTE and WiFi (and everything else in the 5Ghz band) play nice with each other?

2) If this works, is this a model for going forward? Why not have the mobile carriers provide services in unlicensed bands versus licensing them valuable spectrum?

3) Does this provide T-Mobile a cost advantaged model for competing in mobile broadband (not having to spend billions to buy licensed spectrum)?

I suppose there are many more interesting questions that will be surfaced and maybe answered as a result of this move by T-Mobile. I’d be very curious to hear them in the comments.

I love that T-Mobile is playing the scrappy underdog role so well in the mobile carrier market and continuing to innovate and disrupt the established norms and business models. I’m a happy and proud T-Mobile customer and plan to remain so.


Comments (Archived):

  1. Attore

    valuable spectrum is only valuable because it is wanted might be a somewhat Obvious issue here 🙂 I am not impressed with Tmobs coverage, so anything they do might be an improvement to a somewhat shoddy offering if you do not live in a big city 🙂

  2. JimHirshfield

    I think it’s a cool move, ’cause as I understand it, my phone connects to WiFi when/where I want it too. So even if there’s LTE available at that same “when/where” well, alright…got options.

  3. andrewwatson

    The value in licensed spectrum is FCC enforcement (stiff civil and criminal penalties) when people infringe on it or interfere with it. I’m interested to see how they pull this off but I’m not sure how they can meet FCC requirements for availability with frequencies they can’t police.

  4. LE

    3) Does this provide T-Mobile a cost advantaged model for competing in mobile broadband (not having to spend billions to buy licensed spectrum)?If it does I see this as going to their bottom line as opposed to chopping prices which others will simply meet. Then they can use the money to cover any deadspots or to increase their marketing. My thoughts on T-Mobile currently (which could be wrong) are simply “not as good as Verizon or AT&T” so that’s what they need to figure a way around.

    1. Joe Cardillo

      That’s my read, too…it feels like a catch-up move and not competitive advantage. I’m a loyal T-Mobile customer but the network just doesn’t do it.

      1. LE

        I think cell network coverage buying psychology is similar to consumer behavior and purchasing of AWD or 4WD Suv’s. [1]Even if the network is fine where you are 98% of the time, you still would like to not think that there will be a dead spot on the 2% that you happen to be on vacation or go to visit someone in the sticks. People do buy for the “outlier” events.[1] People in even mildly snowy climates like to know that they have the ability to drive in snow even if they very rarely drive in snow because of the FUD that comes with a negative such as that.

        1. Joe Cardillo

          Good point, that’s consistent with how most people around me seem to view coverage. I’m probably one of the 80/20 customers, if it’s good most of the time I’m happy…though in T-Mobile’s case the inconsistent service indoors is fairly regular.

  5. JimHirshfield

    Don’t some cordless phones operate in the 5Ghz spectrum? ….specifically, 5.8Ghz

    1. Peter Beddows

      @JimHirshfield: Yes they do and, in most cases, they do it much better than the older cordless phones that use the 2.4GHz band but that is also because they use a different form of technology from that used in older cordless phones; however, their power is limited hence the range is equally relatively quite limited just as Bluetooth communication range is limited and that is why any of these types of devices individually can be operated without having to have individual licenses. The manufacturers, however, do have to ensure their products operate within band and power limits to ensure overall freedom from interference.Along those lines, if you have any wireless cameras, most of which also operate in the 2.4GHz band, you will notice raster tearing on your monitor due to in-spectrum interference from all kinds of other RF generating devices including Microwave cookers. This demonstrates perfectly how co-existence of RF generating systems can be quite hard to accomplish without considerable engineering development and testing work before product release to the market.

      1. JimHirshfield

        Peter – thanks. That’s a great explanation.

        1. Peter Beddows

          You’re welcome. I thought your question was well placed in relation to this discussion.

  6. Matt Kruza

    Does is work as “phone defaults to wifi”, if wifi is not available than the LTE technology takes over? If so, that is awesome, and frankly is sort of what republic wireless does piggy-backing off of Sprint’s network as a MVNO. Having absolutely no customer service though Republic wireless is hard to make work for my taste. Regardless, probably 90%+ traffic can be offloaded to wifi networks (work, home, starbucks, Panera’s etc.). Makes complete sense, is inherently deflationary (aka good for everyone but the big Telco’s), and will be very bad for Apple over the mid-term (5-10 years), as once the cell phone data access is reduced and the purchase of the phone is unbundled than people (not all.. just many) will opt for cheaper phones.

    1. LE

      I don’t even enable or use wifi anywhere. [1] I’m not interested in the potential cesspool that comes with free or even paid wifi and hotspots.[1] Not even in the house or at the office. Because then I’d have to remember to turn if off when I walk into the Starbucks for example.

      1. JimHirshfield

        There’s a setting on most phones to control that. IOW, just connect to the wifi that I’ve authorized…and not to anything like Starbuck’s wifi.BTW, my neighbor has an interesting name for his home wifi network: VirusDownloadNet. That keeps the free-riders away.

        1. LE

          VirusDownloadNetActually it would make more sense if he didn’t broadcast the SSN at all.”setting on most phones” – I know about that.Common trick back in the day was for people to use the call sign of a known acceptable point like “linksys” with no password and boom you are connected to them. And about probably 50 other ways as well.Here is the point Jim. With respect to things like this if I don’t have the time to fully figure out if I am safe (as I want to be) then I do what I have to do and have done and remove all doubt.You know all those hackings that you always read about? Those are getting around things that (as I like to say) the “white men have sworn they have figured out” security. This has been going on forever.Edit: “and remove all doubt” in other words trust LTE Verizon or AT&T better than wifi which is not to say there are not security issues with that obviously..

    2. Christie Ma

      I was a Republic Wireless customer for almost two years (though I kept my regular cell phone plan with T-mobile as well). I tried their first phone (dual-band Motorola DEFY XT Smartphone) and barely used it because so many calls would drop. Their second phone, the Moto X, was better. As an early adopter, it was nice to have an unlimited data plan for just $25-30 per month. A few months ago, I gave up on Republic Wireless altogether because the phone had a really short battery life (a lot of software bugs) and I still depended entirely on my T-mobile phone for calls.

      1. Matt Kruza

        Yeah, I can totally understand that republic wireless’s execution has been non-ideal (like I said, I don’t even use them right now). But, I still think the economics make it the likely winner over the long-term

        1. Christie Ma

          I agree with your point. I think many people will opt for the cheaper phone in the long-term. In the US, however, I don’t feel there are many phone options to begin with so I wonder how much the price can drop. In contrast, consumers in Mainland China buy on average two new phones per year. I would equate phone ownership in China with car ownership in the US. That is to say, there is a lot more variety and consumers have a much wider range of preferences and expectations.

          1. Matt Kruza

            In china do the carriers subsidize the phones the way the US does? My contention is that is pretty much the whle reason the CHOICE of phones end up being low. There is actually a bunch of options (go to Walmart and there will be 10+ sub 100 smart phones all better than the IPhone 3 or 4.. from only what 5 years ago that meets most peoples needs), its just the carrier subsidy andlack of carriers causes most to choose iPhone or one of a few popular android versions

          2. Christie Ma

            No. Chinese carriers do not subsidize the cost of the phones. Back in 2012, the most basic candy bar Nokia phone cost 500RMB (about $100). The cheapest GSM cell phone started at 1000RMB. Most Chinese consumers are willing to spend a month’s salary (2000-3000RMB) on purchasing a phone. All phones are unlocked. You can choose to sign up for a package but that’s optional. Many Chinese use pay as you go plans (there are pre-card phone cards and independent kiosks all over the city). In fact, anyone can buy a phone and a SIM card without registering a name. Around Chinese New Years, there is a lot of phone theft. I’ve also noticed the quality of the hardware is not as good (ie shorter battery life).

          3. Matt Kruza

            Thanks for the explanation. Very interesting willing to spend a month salary on a phone (hard to imagine anyone doing that here …). But phones being unlocked helps bring down data costs (comparatively) I would think

    3. Girish Mehta

      No, this is about using the unlicensed spectrum. “WiFi offload” is a little different – where operators take traffic off from mobile network to WiFi hotspots where possible. For instance, here in India (from few years back) -…Google will also be attempting to merge WiFi and cell networks, but they will approach it as “WiFi First” rather than “WiFi offload” (coming at it from the opposite direction than what an operator might). From MWC today..http://bits.blogs.nytimes.c…While the point Fred seemed to be highlighting in this post was about T-Mobile’s plan to use the unlicensed spectrum rather than WiFi Offload. Thanks.

      1. Matt Kruza

        Thanks, really appreciate the detailed response. And I heard google was entering the space but interesting to see that they are doing wifi first…may take a decade? but just feels like again the economics are too much in favor of the wifi first approach

  7. Elias Rothblatt

    This is especially interesting given Google’s upcoming move to become a MVNO (rumored to use T-Mob and Sprint service and look for best signal between cellular networks and WiFi).http://www.fiercewireless.c

  8. Rick

    While I accept the technological changes coming throught, I fear if this would be a conflicting point between the telecoms, carriers and the FCC. By way of usurping the competition I am only concerned if the carriers can pull this brash advances off

  9. LE

    I love that T-Mobile is playing the scrappy underdog role so well in the mobile carrier market and continuing to innovate and disrupt the established norms and business models. I’m a happy and proud T-Mobile customer and plan to remain so.All I care about is “more bars in more places” whatever else a company does, say, “help feed the poor” or “donate x% to this or that” doesn’t matter to me at all. I just want a product that works well with the least aggravation or problems.

    1. fredwilson

      different strokes for different folksi am happy to accept poor service if i get unlocked phones, no contracts, etc

      1. LE

        Well with the “unlocked phones” I can see why (a benefit to you). (Note Apple’s profits seem to indicate that many people are in my camp on this issue …)Anyway, quite frankly, why do you care about contracts given your financial situation? You sound like my mother who has a bunch of old furniture in her house and wants to get $75 here and $25 there rather than just having someone haul it away (she doesn’t need the money..) And I said “Mom! It doesn’t matter just give the sofa to the painter and save yourself the trouble!”

        1. fredwilson

          i care about money stuff because i care not because of the money part

          1. LE

            I guess I would like to know “why you care” specifically. Is it because you think the cell phones are taking advantage of people? Or?Contracts and commitments are a necessary evil that companies have to use because customers in certain cases need to be on a short leash or they will just flip with the wind. So they are a bit of certainty that allows for business planning.Assuming I am reading you correctly there are valid business reasons why the cell companies want a commitment.This is really not any different than the fact that the office space that you rent wants a lease of a fixed term and not “month to month” (if so, the price would be higher).

      2. Rick

        +0.5.I only give a half because we shouldn’t need to settle for poor service to get unlocked phones, no contracts, etc.

      3. Cam MacRae

        You’ve got it arse about, ya crazy kid! Me? I’m happy to pay for unlocked phones so I don’t have to accept poor service!

    2. JimHirshfield

      All I care about is “more bars in more places…”Move to Pittsburgh. They have more bars per capita than any other city in USA.[1][1]

      1. LE

        Interesting however I expected more from something in Ibtimes actually.First they only give data on 5 cities that I saw. Second comparing tourist heavy LV “per 10k residents” to Pittsburgh (which let’s say, 5 or 6 people visit per year?) doesn’t make much sense anyway.Not only that but the bars in L.V. I would imagine include bars in hotels that serve many more customers than a local Pittsburgh bar. So this data in both directions is messed up and not normalized in any way, at least from this article.I could go on and on (but I will stop) and just say “wouldn’t you want data on how much alcohol is consumed vs. the quantity of bars”? Especially when you don’t even know how many seats each bar has on what types of neighborhoods the bar is located in. In your CT neighborhood by the way is there a bar on the corner? Probably not, right?

        1. JimHirshfield

          No bars in my neighborhood.Just trees and houses.

  10. Jon Smirl

    Have to ask an expert, but I think the key difference is maximum allowable power. Maximum power in ISM bands is 1W which severely limits the range. For the purchased spectrum most phones transmit at about 2W.But big difference is on the tower. Cell towers transmit at 10-30W, with the ISM band they would be restricted to the same 1W as the phone.

    1. Joe Cardillo

      Good point. Plus the elephant in the room is that T-Mobile service is at least semi-frequently spotty indoors, so LTE in the wifi spectrum may be just as much about correcting that as anything else.

  11. Vishal

    The standards bodies (3GPP and others) are still working through the specs on how to get cellular (LTE) and Wi-Fi technologies to co-exist. There are some fundamental differences on how the L1/L2 protocols are setup between these technologies – so it will be interesting to see what variants of these specs operators will eventually deploy.

  12. Jon Smirl

    Why do they have to run LTE in the ISM band? Just so that they can sell the service? If they used existing wifi protocols everything would play nicely. A better strategy might be to propose enhancements to the wifi specific instead of jamming LTE into that band.

    1. Boss Hogg

      They want to run it in the ISM band because, compared to Wi-Fi, it has better linkperformance (faster speed), better mobility management, and better coverage.

  13. Volkan

    As an engineer who has been developing network resource management algorithms for top service providers, I would say the way LTE and WiFi works is fundamentally very very different from eachother in terms of how network resources are shared between subscribers. Vendors invest millions of dollars in developing techniques to enable fair sharing of 3G/4G-LTE network resources. These advanced techniques might not exist (or will not be useful) for Wifi (or unlicensed LTE) which will suffer from serious interference. I totally support that service provider’s live network should be partly open to 3rd party developers to ignite innovation. However, if it is not managed well, LTE operating in unlicensed spectrum will lower the service quality for all of us.

  14. Brandon Burns

    I get jealous of my friends with Verizon’s usually top notch service, but T-Mobile gets better by the day and its things like this (and, mainly, the no-contract contracts) that keep me on their network.A good example of building a brand vs. a product.

  15. Joshua Berk

    One can’t help but wonder what an entirely unlicensed spectrum world would look like.

    1. fredwilson


      1. John Willkie

        Easy to imagine and ponder what will happen: “CB radio” writ large: entirely unlicensed: and useless in any practical sense because “my transmitter is bigger than yours” and due to the simple fact that interference travels farther than a usable signal. My signal therefore will prevent others from using the same frequency in an area than I can transmit to.

    2. Michael Elling

      It’s called tragedy of the commons. Wifi works because of part 15 power limits put on devices in the ISM bands like garage door openers, microwave ovens etc… by govt regulators (aka the FCC).By carving up the commons into neatly defined spaces (and with the benefit of material, ie walls, blocking radio waves) we got a very well ordered commons over the past 30 years. The term cellular (typically applied to licensed bands) is a description of frequency reuse. Think of wifi as being near infinite reuse or cellularization of the ISM bands.

  16. Matt Zagaja

    If you live in a densely populated area or an office building you soon become acquainted with the challenges presented by use of WiFi. I’m not really excited to experience them on mobile networks as well. Increasingly I find myself disabling my WiFi on my iPhone while I am out and about because it tries and dies when connecting to a hotspot, but Sprint (of all carriers!) has increasingly reliable LTE service at higher and higher speeds. All things being equal I’m sure this will be helpful for T-Mobile customers but not sure it will make life more pleasant for WiFi users.

  17. ShanaC

    I wonder what the tech they and competitors are going to develop around this is going to look like. Also, thinking back on old Larry Lessig “Code is law” stuff – what will the opposite people/pirate/not pirate side look like (because t mobile is big and corporate, and say the community of red hook doing a mesh network is small, and this could set off an interesting clash in the commons spectrum)

  18. ShanaC

    also, how much do you think this is in response to the move to title 2?

    1. Rick

      Hmm… Good question. Did something change that allows this where before it wasn’t allowed.

      1. Michael Elling


    2. Michael Elling


  19. Rick

    Fred! Where’s the opportunity for *us* to make some fat stacks of cash from this?

  20. William Mougayar

    We have our version of the underdog trying to disrupt the incumbents in Canada: WIND mobile. All powers to them.

    1. SubstrateUndertow

      I haven’t been paying attention, thanks for pointing that out !

    2. Rick

      William I noticed you haven’t responed to my response about your concern about twisted information..This is just a difference of opinion. I think most of what’s on the internet is opinion based and usually not verifield by the poster. It appears you feel differently..But let’s not be small about this. I think we should both have our own opinions. Just because they clash is no reason to get upset..I won’t crack jokes about your views anymore. Let’s be bigger than this difference of opinion and put this behind us..What do you say William? Can we just agree to disagree and let this go?

      1. William Mougayar

        If you want to have a healthy discussion, please stick to discussing the issues and topics, and avoid personal references or personal attacks, even if they are perceived that way, especially if you don’t know the person well. And most of all, don’t be condescending (e.g. “let’s not be small about this”), and don’t be creepy (e.g. referencing private emails or calling LE).

        1. Rick

          While many today use email I prefer to use the phone. It’s just what I do. I find it easier to get work done that way. I do use a temp email on occassion but just as an IM type thing..I’ll try to be the best I can be. On your side you need to not let things upset you. First explain why you don’t like what someone says. That way if you’ve read something wrong they can explain..BTW… Some times I take the opposite side. It’s one of the 7 Habits – “First seek to understand then to be understood.” In other words I try to put myself in the shoes of the opposite side of the argument..I’m glad I could talk you into resolving this instead of you staying mad. Nice!

  21. Terry J Leach

    A great example of “permission-less innovation”. Auctioning valuable spectrum to the highest bidder does not encourage innovation and it cost society by establishing monopolies. I really like T-Mobile scrappiness and it’s attempt to change the rules if the wireless provider market. I very happy Sprints attempt to acquire T-Mobile failed.

  22. pointsnfigures

    More competition more better. I am stuck with ATT and an awesome legacy data plan I got years ago.

  23. george

    T-Mobile (TM) just operates differently: they are cheaper and they are building a less painful platform for users. I guess their innovation comes from not being indoctrinated by the influences of the other larger providers – TM actually listens and solves conventional user service problems and dislikes.

  24. Ants Maran

    I probably need to write a blog post about this but my short answer being the inventor behind Qubulus 3G decryption breaking tech and wifi RSSI analytics and most recently the WiTier personal wearable basestation; 1) Shouldn’t be a problem in small scale ie as a sub solution to existing license bandwidth system; but large scale 2) not really as 2G/3G/LTE depends on roll-out planning, maintanence of where base stations are sited etc and if you stop planning… then interference, shadow out, canyons, no burst control etc and that cost needs to be carried. So 3) means yes they save on the license but who and how to pay for the costs involved with quality roll-out of (any) radio?Then Wifi; it is the worst, most energy demanding, protocol as it’s not built for scalability and keeping assigned UE’s hooked to the AP, instead it’s service by availability so that’s why it is sooo difficult to get APs to keep feeding UE (your device).I’d say Great if we can get both unlicensed spectrum working And get it controlled for best roll-out etc And if we could get a new, modern, replacement of the Wifi protocol(s) as they are not up to scaled coop with LTE and definitely not workable for a IoT world as the data will be dropped, resent, dropped, clogged and dysfunctional. LTE for IoT? Not nearly the capacity in basestations unless we totally review 3GPP to get the small messages from IoT/M2M units to coexist on their needs. So you are on the right track, question would be to control and maintain best services.

  25. kenberger

    I’m here at MWC in Barcelona now.We’ll see how this plays out. That article got things slightly wrong– Tmo is *thinking* about this.My quick answer is that you’ve got a Tragedy of the Commons issue which will make things tough even for a carrier as relatively cool as Tmo USA to pull off. 5GHz has much better physics qualities for this than 2.4 would have (more channels, less interference, although at the expense of range), but I’m still not bullish about this working out well.

  26. Tom Labus

    Los Nets on fire in Brooklyn

  27. Bill

    The answer to the ultimate question is “yes”. Not too far off, wifi and other forms of unlicensed spectrum (750+ MHz avail vs 600 MHz-ish for licensed) will be the persistent connection with licensed as the fall back as opposed to now where the opposite is true. Globalstar’s TLPS is a good example of Wall St buying into even rudimentary forms of this. There is a ton of >2 GHz up spectrum and it’s ideal for short-ranged small cells. The hurdle so far has been technology, but companies like Qualcomm are bringing commercially-viable licensed/unlicensed hybrid solutions to market at a fast rate.

  28. Peter Beddows

    I trust that I have read every reply in this stream at this juncture and thus can safely say that, so far, I appear to be the only licensed (Extra-Class) ham “AF6DT” in this thread as well as the fact that I did my early college time with British Telecom and was also ham licensed in the UK. I mention that fact simply because the very idea of unlicensed activity on any RF band typically results in the complete and rapid reduction of usefulness of that band which is why we have licensing of the use all forms of RF (Wireless) communications and have a an internationally agreed scheme of definitve RF bands.Technically, there are no unlicensed bands, per se, and in the absolute, not even any authorised unlicensed band use: The fact that there are devices that you can operate without having an actual license is simply because those devices have been designed to operate within an agreed wireless band spectrum range by international agreement that such operation – in meeting the specific requirements for such operation – can thus be operated without the need or requirement for specific individual licenses.All band usage is agreed internationally by the august group referred to as the ITU and all licensed amateur activity is further governed by the IARU. I quote, for expediency to clarify here from Wikipedia:”The International Telecommunication Union (ITU), originally the International Telegraph Union (French: Union Internationale des Télécommunications), is a specialized agency of the United Nations (UN) that is responsible for issues that concern information and communication technologies.[1]The ITU coordinates the shared global use of the radio spectrum, promotes international cooperation in assigning satellite orbits, works to improve telecommunication infrastructure in the developing world, and assists in the development and coordination of worldwide technical standards.The ITU is active in areas including broadband Internet, latest-generation wireless technologies, aeronautical and maritime navigation, radio astronomy, satellite-based meteorology, convergence in fixed-mobile phone, Internet access, data, voice, TV broadcasting, and next-generation networks.”In and of itself, the above may not prove my case about the need for licensing and agreements of how different modes of communication may operate within any given shared use spectrum but suffice it to say that there is a vast body of proven case studies that show how unlicensed use of RF bands results in polluted are-waves and significantly reduced serviceability of those air waves.

  29. Peter Beddows

    Having expounded, as below, upon the bureaucratic issues underlying “licensed” versus “unlicensed” use of RF spectrum, I totally agreed with @FredWilson regarding “This move by T-Mobile is very interesting to me in a number of dimensions” ~ yes it is.The questions that Fred poses are important and getting answers to them would be helpful. T-Mobile is hardly likely to produce a service that would blatantly ignore the agreed standards underlying its use of any spectrum.On the other hand, I also agree with Fred that “auctioning off the most valuable and useful spectrum to the highest bidders, who often warehouse and under utilize it, is (very) bad policy.”I am merely advocating that, in practice, there is no hindrance or burden against product and/or service innovation as a result of the regulation of RF spectrum: One simply has to follow the agreed guidelines governing how one implements any new service or product within any given “individual use unlicensed” band: This in no way mitigates against innovation.As a matter of fact, there are many licensed hams, never mind commercially minded engineering innovators, who are daily experimenting with developing new and improved forms of communication technologies without having any problem with the agreed upon system of respective band communication management.

  30. Hutchy

    Rather than the consumer market, what role can LTE play in the resources sector such as Mining and Oil and Gas?It’s the industrial scale and application that is most interesting.

  31. Guest

    Lorium lipsum ……………

  32. Guest


  33. LE

    But I already have just about “all the bars I can eat” so why should I care about that?Little side story here. There is a cell tower on top of a building that I own a condo in (Jersey Shore). The tower has been there for a long time paying monthly rent which of course offsets the condo fees. There is a building right across the way that doesn’t have a tower (which is great that way we don’t see the equipment since it’s on the top of our building). Missed opportunity for them.Anyway a few years ago the people who lease the tower came and paid about $1,000,000 for rights since the lease expired. Not even all the rights we still get monthly rent for something as well. Plus they pay for any and all roof repairs from what I am told. So now there is a huge surplus in the building which of course helps greatly to keep condo fees down. Not only that but the building across the way (that doesn’t have the tower) ran into problems after Superstorm Sandy because of things that their insurance didn’t cover and other mismanagement. Otoh our building had plenty of reserves and even bought a backup generator that will keep the place running through any store in the future.