[Galaxy S III General] gliatiotis:
LTE modems require a lot of memory to operate and of course increase power consumption .

The inclusion of 2GB of RAM in some new LTE enabled Android phones is done primarily to cover the needs of the LTE subsystem when you use it to browse content on the device itself using Chrome , the stock browser etc .

Of course , 1GB of RAM is more than what LTE needs , however it is much simpler to create a 2GB module on top of Exynos in Samsung's case , than just add a seperate RAM module for the LTE radio like Apple did in the iPhone 5 .

Exynos can "speak" LTE just fine , like almost all SoC's can . The problem was artificially created from Qualcomm itself by two different moves they made .

The first one was releasing an MDM module ( MSM's have both radio and Application proccesors , APQ's have only the AP's and MDM's have only the radio part ) capable of only LTE data transfer modes , without even the fallback option to UMTS / GSM for voice calls .

They also released the MSM8960 , the SoC used in many LTE enabled phones (and some European devices that lack LTE too ) which had LTE integration and supported Voice fallback along of course with support for UMTS and GSM for both data and voice .

A manufacturer wanting to use another SoC instead of the MSM8960 would have to integrate both an MDM module for Qualcomm for the LTE data part and another solution from another maker (like Samsung uses X-Gold's ) to provide both LTE and Voice / Data in UMTS / GSM networks .

The obvious downside is the increased complexity , increased testing , requirement for more space inside the handset and of course vastly increased power consumption since both radio parts have to be initiated at boot and be active all the time .

The only practical advantage would be the ability to transfer data through LTE and make a voice call at the same time which is not possible in most if not all implementations using the MSM8960 as their solution of choice .

The other problem was the fact that Qualcomm holds most of the patents used in LTE as a standard and they use them as a way to hold back manufacturers from creating solutions that work on the LTE bands used in North America , mostly to ensure higher proffits from makers choosing their solutions .

They do however realize that outside north America where networks require in most cases the ability to work in both LTE and UMTS / GSM networks at the same time , they have to either provide a solution capable of doing that or just do nothing .

Since LTE is wide spread in North America for the time being and this is were most revenue comes from , they just want to secure their position there .

At some point , Qualcomm made the MDM9600 and MDM9615 (the one used in iPhone 5 ) available to phone makers , the first MDM supporting voice functions on top of LTE and HSPA data capabilities .

This move was not made to support other SoC makers like Samsung or NVidia , even though they will benefit from it ( HTC One X+ for example ) , it was more of a way to provide makers the ability to make Quad-Core krait powered devices that are LTE capable . The only available quad core krait solutions are from the APQ category and lack the radio part (they do provide exceptional performance though....) and since the inclusion of two seperate Radio parts is still not an option , MDM's had to suddenly aquire voice capabilities .

Samsung had to settle on this logic for the North American market and create the Qualcomm powered Galaxy S3 in order to provide LTE since they had to get it to market before the MDM9600 availability and they created the i-9035 for the rest of the world where Qualcomm is not interested and LTE tranfers are required to be possible at the same time with voice calls since most European and korean networks operate LTE using fallback to UMTS / GSM for voice but require both of them operating at the same time .

In any case , the added RAM on i-9305 is a welcome option , but certainly not a deal breaker for someone that already owns a i-9300 version .