GSM Switch-Off: AT&T Targets 2017

Yes, I know NTT-DoCoMo has long shut down their 2G network but that was a special case as it was their proprietary technology little used anywhere else. Since then there have been rumors, speculations and analysis when network operators in other countries in the world might switch-off their more popular and wide spread 2G GSM networks. Now AT&T has given a date for their US GSM network shutdown, it's envisaged for 2017 as reported by the Wall Street Journal.

2017, that's 5 years from now. I've noticed AT&T making a lot of progress of deploying UMTS in remote areas and 5 years is enough time to continue the process in addition to rolling out LTE. Also, when I was recently in Canada, I was positively surprised about the 3G coverage along highways in sparsely populated areas between cities. On 850 MHz, the coverage area of a UMTS cell is similar to that of a GSM cell and for carriers that quit CDMA in the past to go to UMTS it obviously did not make sense to deploy GSM alongside.

5 Years ago, back in 2007 I had a post on this blog about when GSM will be switched-off. Let's take a look what I thought at that time and how that matches today's situation and AT&T's announcement:

"So what are we going to see in Europe by 2012 then? In five years from now [i.e. 2012] I expect the majority of subscribers in Europe to have a 3G compatible phone that is backwards compatible to 2G. "

[Yes, right on the mark, more than half of the phones sold today are smartphones and even feature phones have 3G included now, too. There are few models now to be found in shops that are only GSM.]

In urban areas, operators might decide do downscale their GSM deployment a bit as most people now use the 3G instead of the 2G network for voice calls. Cities will still be covered by GSM but maybe with fewer number of available channels / bandwidth.

[Mostly on the mark: While for many years people have switched off 3G in their phones for fear of higher battery power consumption and thus made most of their voice calls on 2G, that's a thing of the past in 2012. Accessing services on the Internet from smartphones has become a mass market trend. As a consequence, most voice calls from such phones are now established over 3G networks. In the UK, O2 has deployed UMTS 900 in London. It's still a bit of an exception in Europe. O2 in the UK is in the fortunate position of owning half of the 900 MHz band so it could easily carve out 5 MHz and put a UMTS channel there. There are no announcements of similar intentions by other European network operators for the moment. However, with voice calls migrating to 3G due to the use of smartphones I think this will not remain the only major urban deployment of UMTS 900 in Europe.]

"Such a scenario could come in combination with yet another equipment refresh which some operators require by then for both their 2G and 3G networks. At that time, base station equipment that integrates 2G, 3G and beyond 3G radios such as LTE could become very attractive. The motto of the hour could be "Replace your aging 2G and 3G equipment with a new base station that can do both plus LTE on top!"

[Yes, that's what we see today when new network equipment is being rolled out. Huawei, for example, calls it Single RAN and NSN's Flexi concept goes in the same direction]

"I wonder if it is possible by then to only use one set of antennas for all three radio technologies!? If not, adding yet another set of antennas on top of an already crowded mast is not simple from both a technological and psychological point of view."

[Today, at least GSM and UMTS use the same antenna but I haven't yet seen what kind of antennas are used at base station sites at which GSM, UMTS and LTE are deployed, all in very different frequency bands. Single antenna solutions exist, even in variants that have several antennas in a single casing, as for example demonstrated by Kathrein at the Mobile World Congress in 2011].

When looking at all of these developments I think it is very likely that we will see a lot of movement around what kind of technology is used in the 900 MHz band in Europe. In many countries, licenses for the 900 MHz spectrum will be renewed, reassigned or re-auctioned in this time frame and in many countries auctions for the 800 MHz digital dividend band and the 2600 MHz band for LTE have not yet been undertaken. All of this will have a significant impact on what network operators will do with their 900 MHz spectrum assets. My prediction is that GSM will still be around in Europe in 2017 but the debate on when to switch it off will be in full swing. I've described how such a phaseout could look like in a post on 'GSM Phaseout Scenarios'. Despite written in 2008 I think it still applies from today's perspective.


4 thoughts on “GSM Switch-Off: AT&T Targets 2017”

  1. Regarding O2 and U900, they have now gone nationwide with their roll-out. They have even modified their coverage checker on their website and ask the user to pick whether they have a U900 device or not so they can display the 3G appropriate coverage. See here..

  2. AT&T Mobility is only just deploying UMTS in Alaska, and even that is only in the big 3 cities and on the North Slope. I’m skeptical we’ll ever see 2G go away up here.

  3. I think AT&T and some other operators can meet their target of switching off their GSM systems due the following thoughts.
    First, a mobile operator should make sure that there are no GSM-only mobiles in their network. I recently checked the new shared tariffs from Verizon Wireless and I couldn’t find a tariff to which I would be able to connect with my own cell phone. I need to buy from them a mobile even if I want a Pay as You Go tariff (if I am wrong about this – please correct me). It appears to me that the operator wants me to change my mobile every two years. If AT&T has the same strategy about mobiles, then it can make sure that in a couple of years there won’t be GSM-only mobiles by selling 3G capable phones. Then it would be useful to restrict users to switch off 3G mode on their mobiles. I’m not the specialist in American market and smartphones, but as far as I know when an operator sells a mobile, it installs some programs on it. In other words, the operator has access to the mobile and OS, so I think it can somehow lock the capability of a mobile to be manually switched to 2G-only mode by a user. This will give the operator the possibility to monitor 2G usage in their network. Of course you can derive the data about mobiles and their capabilities from the real network, but how do you know that a 3G-4G capable smartphone isn’t in the area with 2G coverage only? Knowing about 2G traffic in your network, you’ll be able to monitor the trend and decide about switching off or not your 2G network.
    Secondly, there is a problem with coverage. It’s clear that 3G coverage should be at least as large as 2G coverage before switching off the latter. Providing 3G coverage as vast as 2G could be a real challenge for an operator as the above comment about Alaska proves. However Alaska hasn’t seen UMTS not because it’s technically impossible, but because the company hasn’t aimed this so far. Usually a company has a budget to spend on capacity, coverage and features, and that money as always not enough to cover all needs. However, if a company aims to deliver 3G coverage as large as 2G and is ready to spend money on this, than everything is possible, at least from technical point of view. One can argue that it’s a lot of money and it’s not economically reasonable. Yes, it’s true, to some extent. There is a solution, however, and it has already been mention by Martin and sounds “Replace your aging 2G and 3G equipment with a new base station that can do both plus LTE on top!” As operators are gearing up for LTE they can choose to use SDR modules (software defined radio). With such module it’s possible so switch from GSM to UMTS or LTE by means of software. Not only an operator replaces their aging 2G equipment, but is also capable to switch from 2G to 3G, thus providing the same coverage (don’t forget about licenses, though, they represent a chunk of money). And modern SDRs are capable of operating in two modes concurrently – GSM+LTE, for instance, which is great.
    Thirdly, there is a spectrum issue. SDRs are nice, but they have an issue called instantaneous window, which is 20 – 35 MHz in modern modules (varies from manufacture to manufacture). For instance, a GSM1800 module can operate in the whole 1800 band (1805 to 1880 MHz), but the frequencies assigned shouldn’t vary for more then 20-35 MHz. The same with concurrent mode, both technologies (GSM+LTE, for instance) should fit into that window. This restriction has to deal with Power Amplifier characteristics and can be mitigated in the future. I’ve heard that the US operators are planning to make some swaps of their spectrum among each other, and if they think through such issues carefully, they can derive from SDR as much advantage as possible.
    So, supposing we’ve done the aforementioned and our network has been equipped with SDR, we’ve thought through spectrum issues and in our network there aren’t 2G-only phones. Now we monitor the network, observe how much 2G traffic we have and where, how many 2G roamers visit our network and how much money they leave here, and one day, judging all pros and cons, we’ll dare to switch GSM off.
    The above represents my opinion, so please feel free to criticize. And I apologize for the long comment.

  4. While normal end customer devices might not be a problem of being replaced by UMTS/LTE capable ones over some years, I believe that the whole M2M market may have a much stronger influence on a potential decision to phase out GSM.
    I guess that still up to now most of the M2M business uses GSM/GPRS/EDGE devices because most scenarios don’t rewuire high data rates and also these are optimised for low power consumption. A GSM module build in any kind of black box with special developed services on it can’t be replaced very easily.
    So my personal feeling is more that the operators will keep a minimum of resources/spectrum available for these legacy devices (at least as long the spectrum licence plans of the regulatory authorities does not go into a different direction).

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