AT&T Killing Its 2G Network By 2017

The Wall Street Journal reports that AT&T has plans to shut down its 2G network by January 1, 2017. Roughly 12% of its contact wireless customers — 8.4 million people — have 2G handsets, and the company plans to gradually move them to devices running on more modern networks. "The timeline for the 2G shutdown was made in a filing with the Securities and Exchange Commission on Friday. An AT&T spokesman said the company no longer sells 2G handsets to contract or prepaid customers. Along with phones, the company does have some other devices connected to its 2G networks, but it also expects that they will transition to more modern technology in coming years. As the carriers deal with ever increasing data usage on their networks, they also are facing a spectrum shortage to carry all the traffic. Shutting down legacy networks is one part of the plan, along with acquiring new spectrum and finding innovative ways to use unused airwaves."

No conspiracies, no Evil, just more bandwidth

[Art Popp]

Spectral efficiency in symbols per Hz:

2G .45
LTE 16.15

So we ~ 32 times as much data out of the 2G spectrum if we get people and devices to upgrade.

Re:RIP GSM

[Anonymous Coward]

CDMA is all that is modern with cell phones. GSM is a dead technology. What people call 3G GSM is actually CDMA (WCDMA). LTE/4G is based on CDMA.

Re:RIP GSM

[Anonymous Coward]

"CDMA" stands for Code Division Multiple Access, which has been used for pretty much every modern cellular technology (the alternative for mobile handsets being time division).

It also has an old, obsolete cellular network protocol named after it.

Re:Just Peachy

[Guy Harris]

I have been using a dual sim GSM quad band for travel from the US to Germany. Looks like I'll have to carry two phones again. :(

Is that "GSM" as in "it only does TDMA, not any flavor of CDMA including those used for UMTS in Germany", so that it won't work on AT&T once they shut down 2G and wouldn't work on any 3G or later networks in Europe either, only on European 2G networks, or "GSM" as in "it only supports the GSM/3GPP protocol stack, but handles both 2G and 3G", so that it'll continue to work on AT&T?

Or is it that the only frequencies it works on with AT&T are their 2G frequencies, so that, whilst it might continue to work fine in Europe if it handles their 3G frequencies, it won't work with AT&T in the US once AT&T stops using those frequencies for 2G unless AT&T switches them to services that your phone also supports?

Re:RIP GSM

[Guy Harris]

you are mixing stuff up, very badly. '4G' LTE is an overall product, CDMA or WCDMA is a only a wireless system.

LTE is an overall product that doesn't use CDMA for its air interface; instead, it uses OFDMA [3gpp.org].

Re:RIP GSM

[frieko]

Interestingly the one thing that LTE doesn't inherit from WCDMA is the CDMA-based air interface. LTE uses OFDM, which is a radical departure from CDMA. OFDM uses a drastically slower symbol rate to reduce the effects of echoing (multipath), but then makes up for the reduced capacity by adding thousands of narrowly-spaced carriers. Because combating multipath is the main limiting factor in practical wireless the overall efficiency is drastically increased.

Re:RIP GSM

[downhole]

Felt like doing my best at a mobile tech summary, and here seems as good a place as any:

One common mix-up is between air interfaces and complete cellular systems. CDMA and TDMA are both types of air interfaces - how the phone and the tower actually communicate with each other. CDMA is also used to refer to a complete cellular system which was originally based on the CDMA air interface. GSM also refers to a complete cellular system, whose original incarnation, usually known as 2G, was based on a TDMA air interface. Near as I can tell, it's pretty much universally known that CDMA air interfaces are vastly more efficient than TDMA, but the actual cellular systems have leapfrogged other a bunch of times.

I think GSM started out doing data on a separate TDMA frequency called GPRS, which worked, but was pretty slow and inefficient. CDMA started doing data over it's same frequencies, which was a bit faster and much more efficient. Then GSM came up with EDGE to improve speed, and then CDMA came up with CDMA2000, and then GSM switched to WCDMA/UTMS, which actually used a CDMA air interface, and CDMA switched to EVDO, reaching the peak of 3G. LTE is the next-gen air interface, using a OFDM air interface and otherwise is based on the GSM system, and as far as I can tell, everybody is switching to it. Hopefully, in 5-10 years or so, all the carriers worldwide will use LTE and all of the phones will have LTE basebands that cover all of the frequencies everybody is using, and you'll be able to take any device anywhere in the world and use it.

For various marketing reasons that don't make much objective sense, most of the world ended up standardizing on GSM long ago and only a few countries used systems based on the original CDMA technology, which is why if you have a CDMA phone, you're pretty much boned on international roaming.

And the AndroidFormums post that the AC below me posted is a rip-off of this USS Clueless post: http://denbeste.nu/cd_log_entries/2002/10/GSM3G.shtml [denbeste.nu] which does have a really good explanation of why CDMA is much better than TDMA.