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Why is SK Telecom’s LTE network “Advanced” while EE’s is not?

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U.K.’s mobile operator Everything Everywhere has doubled the speeds on its LTE network, achieving a theoretical maximum throughput to the device of 150 Mbps. That sounds awfully similar to the “LTE-Advanced” upgrade SK Telecom(s sku) implemented last week in South Korea. Yet, EE isn’t calling its network LTE-Advanced. It’s calling it plain old LTE.

This is prime example of how the network terminology the mobile industry is using to market their networks is completely arbitrary.

Both networks essentially accomplish the same thing: They double the amount of spectral bandwidth used over a transmission, thus doubling the speed available to a device. The difference is in how they do it. EE cleared out spectrum in the 1800 MHz band allowing it to create a single 20 MHz-by-20 MHz chunk of spectrum (known in telecom speak as a “carrier”) for LTE use. SK Telecom is combining two 10×10 MHz in disparate frequency bands — 1800 MHz and 800 MHz — using a technique called carrier aggregation.

LTE carrier aggregation is defined by the standards bodies as an LTE-Advanced technique, so SK has reserved the right to call its network Advanced. I’m not trying to belittle SK’s accomplishments. The Korean operator is on the cutting edge of today’s network technologies. When the big LTE-A revolution comes, SK is sure to be leading it. But at least today, SK Telecom isn’t able to actually deliver anything that to consumers that a dozen other plain-jane LTE networks can’t offer.

SK Telecom is just taking the first steps down the LTE-Advanced path, and to be honest, those steps are intended to overcome its own lack of a unified LTE spectrum band. Many current and forthcoming European networks already support the 150 Mbps both SK and EE boast about. But because of a technicality European operators aren’t calling them LTE-Advanced (at least not yet). When U.S. operators bring their so-call LTE-Advanced networks online, they’ll basically be doing the same thing: matching the speeds available on the supposedly ordinary LTE networks going live in Europe.

I’m pointing this out because I think the industry is abusing the term LTE-Advanced. The mobile industry is implying a big leap forward in technology. True LTE-Advanced networks will eventually bring about that leap, but today operators claiming to deploy LTE-Advanced aren’t delivering anything we don’t already have.

7 Responses to “Why is SK Telecom’s LTE network “Advanced” while EE’s is not?”

  1. Jason Lee

    can i just ask something, will an LTE-A phone, say the galaxy s4, work on a standard LTE network from say the UK or are they different chips or something, was thinking of getting the korean s4 as an upgrade, and yes i know i will not get to use the LTE-a featured speeds, but I am after an upgrade from my s3 “ultrafast” on three uk mobile and i like the speed upgrade, storage and colour (Blue)

  2. Kevin Fitchard

    Hi Craig,

    No worries at all. I don’t mind criticism, and you definitely make some very good points. I think we just disagree about where LTE-A begins. To me adopting one or two components of the Rel. 10 does not make an LTE-A network make. And while I see your point about CA being the most visible part of the spec, I don’t think it is the most significant one. I think future gains in spectral efficiency and the overall boost in network capacity will have a much more significant impact on what we pay and how we use networks. In my opinion CA’s boosted speeds is just razzle dazzle.

    But please keep the comments the coming. This is a good discussion.

    And P.S. I give plenty of credit to SKT. We named to SK to GigaOM’s Mobile 15 list of most innovative companies specifically because of the work it was doing on CA, CoMP and eICIC. I think they’re well ahead of the game. I just think it’s just way too early for them to be bandying around the terms LTE-Advanced.

  3. Craig

    Hi Kevin,

    First, I enjoy your work, I wasn’t trying to be critical. I just don’t think it’s fair to say that SK T is abusing the LTE-A term, at least not to the degree that other operators have abused the ‘4G’ term in the past.

    It is fair to say that SKT is only at the front-end of delivering a more comprehensive LTE-A experience. But their customers have no other way to get this kind of performance than via the CA feature and an LTE-A device. Maybe it doesn’t qualify as extraordinary, but it does give SK T a differentiated offer in that market. Plus, CA is, by far, the most visible capability of the LTE-A standard. Other features, like interference cancellation, HetNet support, etc. are a bit less tangible for an end-user, and the devices almost certainly don’t support those features yet – this will come over time with future firmware upgrades, newer chipsets, etc…

    I give SKT credit for blazing the trail – most existing LTE operators will enable LTE-A in their networks in the next 12-24 months, and those just now deploying LTE (like T-Mobile USA) are already putting LTE-A ready network equipment in place. (Note that older LTE Rel9 devices are perfectly compatible with LTE-A networks, but obviously they don’t benefit from the new features).

    Thanks again, and keep up the good writing.

  4. Craig

    I agree with his facts, but I don’t agree with his assessment that the LTE-Advanced terminology used here is arbitrary, or somehow being abused. LTE-A is pretty clearly defined. EE can’t claim it, and thankfully, they aren’t trying to. SKT is claiming it, but they should, because it’s true – plus they (and their subs) are paying for it. Looking back, ‘4G’ was/is a badly abused term, primarily by 3G operators trying to say that their HSPA+ networks were somehow suddenly 4G – I don’t see this abuse being repeated here. There is confusion in this situation because of the equivalent speed claims, but each arrived at their performance by legitimate means. Note: It’s worth pointing out that LTE-A also defines other available features that will be introduced down the road as well, but only LTE-A ready chips and devices will benefit.
    I agree with you: what really matters is the performance you can achieve, what devices you need to experience it, and how much the device and the service cost.
    Unfortunately, it’s usually not simple to figure out which devices support 20MHz channels. You can get a clue if you can figure out which LTE bands are supported. The 700MHz bands of AT&T (Band 17) and Verizon (Band 13) are narrow, so devices that only support those LTE bands are limited to 10MHz. Most of the devices shipped in the US over the past year or so have this limitation. But both are lighting up AWS spectrum (1700MHz up/2100MHz down) soon, as is T-Mobile. Carrier widths vary by market, but some AWS allocations are 15 or 20MHz wide, and I would anticipate that most devices supporting this band are likely to support 20MHz channels, hence they could theoretically provide the 150Mbs peak speed. Whether the operators enable this in the network is another matter. Operators should do a better job of identifying which of their devices deliver the top speeds.

  5. Craig

    This isn’t arbitrary. It’s based on the standards. It isn’t the speed that makes it LTE-Advanced, it’s the technology/features used to achieve the speed. In LTE, max throughput is almost entirely determined by the channel bandwidth, which in turn is determined by an operator’s spectrum holdings and regulatory rules. Practically speaking, a 20MHz wide channel is required to achieve 150Mbps peak theoretical downlink speeds in an LTE network. Very few operators have spectrum that is allocated for 20MHz channels.

    SK Telecom gets to 150Mbps by using a 3GPP Release 10 (LTE-Advanced) feature called Carrier Aggregation to create a ‘virtual’ 20MHz channel, capable of 150Mbps in the downlink. They do this because they don’t have 20MHz of spectrum in a single carrier. Note that Carrier Aggregation (CA) requires a more expensive device – essentially you need two receivers operating simultaneously, tuned to different carriers, and the baseband processor needs to operate on those payloads simultaneously – so the LTE-Advanced capable chipsets are more costly than their predecessors.

    Meanwhile, EE is using a single carrier that is 20MHz wide, and they are doing this using existing, mainstream, 3GPP Release 9 (i.e., just plain LTE) network gear and end-user devices. They can do this because they have spectrum that is 20MHz wide to begin with – they don’t need the CA trick to deliver 150Mbps max throughput. The reason they had to wait a bit to deploy this is that earlier device chipsets only supported 10MHz channels – more recently, many chipsets have started to support 20MHz. This approach is much simpler and lower cost than the CA-capable LTE-Advanced chips.

    • r00fus

      So, in short, you agree with the post author?

      What I care about for mobile broadband is a) what speeds I can expect and b) what kind of phone I’ll need to get those speeds.

      Is there anywhere that describes if current phones support 20mhz channels (i.e., does the iPhone5 support it?)

    • Kevin Fitchard

      Hi Craig,

      I’m not saying its speed that makes a network LTE-Advanced. I agree with you entirely that it’s the technology. But SK is only implementing the first step of a multi-faceted standard. The point I’m trying to make here is that SK’s foray into LTE-Advanced is not only just beginning it’s not even delivering anything that ordinary LTE networks aren’t already offering. In my mind if you’re going to promise something extraordinary (or Advanced) you better deliver something extraordinary. This is just pure marketing swill backed up by the merest technical justification.

      I may not have really full explained that in the piece. I was mainly trying to use this as an example that the term LTE-Advanced as carriers are trying to use it today is meaningless. Here’s a post I wrote last week, that kind of sums up all of the problems I have with this kind of technology inflation: