I found an interesting article about radios and LTE connections. The Radio Performance Disparity of the Galaxy Nexus on GSM and CDMA - Mobile Central - Binary Outcast
I have the oppurtunity to either go with ATT or Verizon. The article makes it seems that GSM is a better bet for LTE phones especially in areas with poor reception. I am hoping people can provide insight/comments on LTE phones for GSM and CDMA carriers and the article.
The Radio Performance Disparity of the Galaxy Nexus on GSM and CDMA
The Samsung Galaxy Nexus. It's Google's flagship phone that is designed to complement the Android 4.0 “Ice Cream Sandwich” operating system software. With high end specifications (for 2011) and highly optimized software, the Galaxy Nexus is supposed to show off what Android can really do without any interference from carriers and OEMs. However, that wound up not truly being the case in the United States with the CDMA/LTE variant for Verizon Wireless and Sprint.
By and large, the CDMA/LTE variant sold by Verizon Wireless and Sprint is the same as the original HSPA+ model that is now sold by Google on the Play Store (at least in terms of hardware). It has the same CPU, RAM, NFC chip, screen, cameras, etc. The only hardware difference is the cellular radio structure.
The original UMTS HSPA+ model uses an Intel XG626 baseband modem that is connected to an antenna structure that supports quad-band GSM and penta-band WCDMA for global usage. For Americans, it means that it works on the HSPA+ networks for both AT&T and T-Mobile USA.
The CDMA/LTE variant uses a VIA Telecom CBP7.1 CDMA2000 baseband modem, connected to an antenna structure that supports dual-band CDMA2000. The Sprint model adds another CDMA2000 band that is exclusive to Sprint. Both CDMA/LTE variants use a Samsung CMC221 LTE baseband modem, but the Verizon Wireless variant is set up for LTE band class 13 (Upper 700MHz C block), while the Sprint variant is set up for LTE band class 25 (U.S. Extended PCS, also known as PCS+G). The Verizon Galaxy Nexus has a user-accessible SIM card slot while the Sprint one does not.
While the Intel (formerly Infineon) baseband used to be troublesome on AT&T's network (as many iPhone users that didn't own an iPhone 4S can attest to), the latest generation of basebands work fine on both AT&T and T-Mobile. With 3GPP Release 7 support, it has a maximum downlink throughput of 21Mbps while it has a maximum uplink throughput of 5.76Mbps. In general, the Galaxy Nexus works very well on AT&T and T-Mobile.
However, it isn't the same for the CDMA variants of the Galaxy Nexus. The VIA Telecom CDMA chip is notorious for weak performance. Other notable devices that use the chip are the Samsung DROID Charge and the Samsung Stratosphere. Searching on the web about these devices turns up a lot of complaints about CDMA service quality with these devices.
Jason Perlow of ZDNet experienced more than his fair share of issues while trying to live off of the 4G LTE connection his Galaxy Nexus provided. But he was trying to live off of 4G LTE, not CDMA2000. So why was he affected? Well, the truth is, CDMA/LTE devices require both radios to be active and connected. Not to mention, network authentication and feature provisioning actually goes through the CDMA system, not the LTE one.
The bridge between CDMA2000 and LTE is rather brittle and is prone to failure, because LTE wasn't designed to be bridged with CDMA2000 like that. It was intended to be installed alongside GSM and WCDMA networks, and it handles it a lot better with those networks. So when something goes wrong in the rather terribly buggy CDMA system, the whole phone can and usually does fail. If Verizon Wireless had upgraded the CDMA2000 system to UMTS HSPA+ like most other CDMA2000 carriers across the globe, it would have avoided dealing with this problem.
Also, the CDMA/LTE Galaxy Nexus lies to you (at least, it does now). Originally, the “bars” that indicate signal strength would actually indicate the signal strength of LTE if it was connected to an LTE network. When everyone started complaining about how weak the signal was compared to the Motorola DROID RAZR and Motorola DROID Bionic, Anandtech investigated. It turned out that the signal strength was actually accurate, and that LTE signals are incredibly weak. Previous devices used the CDMA signal strength to determine how many “bars” of signal you have. The Galaxy Nexus did not. It used the LTE signal strength when it was connected to LTE, and the CDMA signal strength when it wasn't. Verizon Wireless issued an update shortly afterward that changed the behavior to match older LTE devices. Newer LTE devices do the same as well.
Combining the fact that the Galaxy Nexus has to work incredibly hard to maintain an LTE signal with the fact that the CDMA2000 radio is horrible and has a difficult time holding onto the connection will lead anyone to the conclusion that it is a recipe for disaster. Is it any wonder why Jason Perlow and many others have so many problems with the CDMA/LTE version of the Galaxy Nexus? Not really.
Of course, this is excluding all the issues with timely updates that Verizon Wireless has caused for Galaxy Nexus owners. Including this issue just makes the problem worse. There are ways to work around some of the issues, though some workarounds will result in permanent degradation of performance. However, it doesn't mean anything if it takes forever for anyone to get any updates that implement them.
In the end, I really can't solidly recommend the CDMA/LTE version of the Galaxy Nexus to anyone. Nor can I recommend any CDMA2000 device that uses a VIA Telecom CDMA baseband modem. The pitfalls just make it a bad experience for everyone.[
Will the snapdragon S4 chip from Qualcomm help with this issue?
Techno Buffalo has an article about T-Mobiles transition to LTE and a T Mobile person stated that their enhanced backload will help T Mobile's LTE. will this help AT&T's LTE Too? http://www.technobuffalo.com/news/w...backhaul-is-the-key-to-a-users-4g-experience/
Here is another article talking about the challenge CDMA has with LTE when the LTE signal is weak
http://www.phonearena.com/news/How-...-you-dont-need-it-and-save-on-battery_id32990
small error?
Hey didn't have time to read what you wrote but gsm is 2g and wcmda is 3g and 4g and LTE is also 4g so what you wrote did not make much sense GSM WCMDA and LTE are 3 different types of radios and here is a tip lo let people help you faster dont add more to what you wrote edit it instead because now it looks like 3 people already helped you
thanks if it helped :good:
For me this is highly theoretical. I recently moved from Dayton, Ohio to Kingsland, Georgia with a Verizon Galaxy Nexus (CDMA). In both places, if I allowed the LTE radio, the phone would get too hot to handle comfortably, and 3G isn't that great either. But in my neighborhood, there is no AT&T or T-Mobile data signal at all. That severely limits practical choices.
One more http://www.extremetech.com/mobile/110711-what-is-lte/7
Dear All,
I recently got this device in Hong Kong and is hapi with its performance!
But I am still wondering if this device could actually use the LTE available in HK?
I knw the msm8960 claimed to be capable of utilizing all frequency of radio,
so is it possible that there is some soft lock in the baseband?
Could i flash the baseband or replace the modem driver from other device to access other frequency?
any idea is appreciated!
Thanks!
Vasco
I think it has to modifiy the ROm and the hardware
I tried to figure out, if our Photon Q is supporting more LTE bands than 1900 MHz (#2 or/and #25).
-> http://en.wikipedia.org/wiki/E-UTRA#Frequency_bands_and_channel_bandwidths
On some sites there are reports for having another band. (Have to search again, I think it was 850 MHz, #26 or 700 MHz, #12/#17/#29.)
I have also searched for supported frequencies for MSM8960.
I found some BlackBerry devices based on that SoC and 2 different versions of supported LTE bands.
One version (UK) supported 4 in europe used bands und the other version (US) supported 4 in US/Canada used bands.
I think that the Photon Q is like the BlackBerry US version and supports 4 LTE bands in US/Canada.
If you need a few sites, I will search again and show it to you.
The strange thing is, if I set to LTE only (via 4636) I can see all 4 carrier (germany).
We have 3 bands with LTE on it, but I can only get signal to max 2 of them.
Band 3, 7 and 20 (1800, 2600, 800 MHz).
The weird thing is, that on band #20 (800 MHz) only 3 carrier are active, so it has to be band #3 or #7.
Maybe I'm missinterpreting things and thats just a sideeffect of crossing bands of LTE US and UMTS Germany.
On stock ROM there was another "secret phone code" to see what the phone-part is doing. (From qualcomm I believe.)
I think I will test it some other day, to see which band is active.
At last, I was never been able to "login" or "register" into my carriers network within LTE.
Please discuss about that possibility, I really want to find out, which frequencies are supported by our phone on LTE.
Loader009 said:
I tried to figure out, if our Photon Q is supporting more LTE bands than 1900 MHz (#2 or/and #25).
-> http://en.wikipedia.org/wiki/E-UTRA#Frequency_bands_and_channel_bandwidths
On some sites there are reports for having another band. (Have to search again, I think it was 850 MHz, #26 or 700 MHz, #12/#17/#29.)
I have also searched for supported frequencies for MSM8960.
I found some BlackBerry devices based on that SoC and 2 different versions of supported LTE bands.
One version (UK) supported 4 in europe used bands und the other version (US) supported 4 in US/Canada used bands.
I think that the Photon Q is like the BlackBerry US version and supports 4 LTE bands in US/Canada.
If you need a few sites, I will search again and show it to you.
The strange thing is, if I set to LTE only (via 4636) I can see all 4 carrier (germany).
We have 3 bands with LTE on it, but I can only get signal to max 2 of them.
Band 3, 7 and 20 (1800, 2600, 800 MHz).
The weird thing is, that on band #20 (800 MHz) only 3 carrier are active, so it has to be band #3 or #7.
Maybe I'm missinterpreting things and thats just a sideeffect of crossing bands of LTE US and UMTS Germany.
On stock ROM there was another "secret phone code" to see what the phone-part is doing. (From qualcomm I believe.)
I think I will test it some other day, to see which band is active.
At last, I was never been able to "login" or "register" into my carriers network within LTE.
Please discuss about that possibility, I really want to find out, which frequencies are supported by our phone on LTE.
Click to expand...
Click to collapse
Dear Loader009,
Thanks for your information! I'm really impressed that you could actually search the carrier in 'LTE only from Germany!
Could you please share the version of ROM you are using?
And if possible, any screenshot? I really want it can be used in HK with LTE(1800, 2100 & 2600Mhz)
Also do you have more information about the secret phone code? I think it would be interesting
Actually, I noted that xt925 and xt905 are using the same chip MSM8960 with LTE usable in HK.
Is there anyone can locate the radio/baseband of their rom and port it for XT897?
I am willing to try it with my machine.
If this work, I think we could use this photon q all over the world!
Any idea?
Regards,
Vasco
disablewong said:
Dear Loader009,
Thanks for your information! I'm really impressed that you could actually search the carrier in 'LTE only from Germany!
Could you please share the version of ROM you are using?
And if possible, any screenshot? I really want it can be used in HK with LTE(1800, 2100 & 2600Mhz)
Also do you have more information about the secret phone code? I think it would be interesting
Actually, I noted that xt925 and xt905 are using the same chip MSM8960 with LTE usable in HK.
Is there anyone can locate the radio/baseband of their rom and port it for XT897?
I am willing to try it with my machine.
If this work, I think we could use this photon q all over the world!
Any idea?
Regards,
Vasco
Click to expand...
Click to collapse
Of course, I was just blind guessing the hardware for xt926 and xt907 are using the same hardware.
If not, there should be one chip controlling the modem channel of the device to be replaced.
But WHICH ONE???
Any expert in this area can solve this question? I am a dummy for radio stuffs
This seems like it's getting pretty interesting.
Sent from my XT897 using Tapatalk 2
Dear all,
I'm also very interested in this topic since I imported a Photon Q to Germany and was wondering if it's possible to use the local LTE 800/1800/2600 bands.
I think the first thing we have to find out is whether the hardware is capable of using other bands than the 1900 band listed on the Motorola website. As Loader009 states he could see LTE carriers which are known to use different bands I assume the hardware can do it. Otherwise the carriers wouldn't have been listed, right? Maybe someone from another country with different frequency bands can check and confirm that he can see those carriers as well?
Thus, the limitation to the 1900 band should be software-made and could be modified by a developer. I hope someone can participate at that point as I don't know much about coding...
I'm using CM10.1.
I can't remember the secret phone code, I have to do research again.
This secret phone code only works on Stock ROM. (I stupidly deleted it, when it wasn't working on CM10 anymore.)
The one secret phone code I used to force "LTE only" was *#*#4636#*#*.
Please DON'T change the baseband (don't even tap on it).
This can do problems to you. (I had to use QPST to recover the supported frequencies.)
Also, developers (afaik) can't modify the modem firmware.
We also don't even know, which LTE bands the Photon Q is capable of. (Except 1900 MHz)
I've got my 32GB SDCard back and will test it in the next few days out.
I hope I'll find that secret phone code, I'll also make a few screenshots.
Got the code!
##33284# <- ##DEBUG#
It only works on stock afair!
I'll test tomorrow, it's about 3am now >.<
disablewong said:
Dear All,
I recently got this device in Hong Kong and is hapi with its performance!
But I am still wondering if this device could actually use the LTE available in HK?
I knw the msm8960 claimed to be capable of utilizing all frequency of radio,
so is it possible that there is some soft lock in the baseband?
Could i flash the baseband or replace the modem driver from other device to access other frequency?
any idea is appreciated!
Thanks!
Vasco
Click to expand...
Click to collapse
I have read the "QU_SnapdragonS4_White_Paper_FNL_Rev6.pdf" and found there following entry:
-----------------------------------------------------------
• Industry’s first fully integrated 3G/4G world/multimode LTE Modem: <<<Supports all of the world’s leading 2G, 3G and 4G LTE standards>>>.
It also includes integrated support for multiple satellite position networks (GPS and GLONASS) as well as short range radios via Bluetooth,
WiFi, FM and NFC.
• Designed for speed, compatibility and power savings:
Snapdragon S4 Processor MSM8960 chipset includes the industry’s only complete platform that integrates all of the world’s leading 2G, 3G and 4G mobile broadband modem technologies on a single chip. This new integrated multimode modem is based on an advanced, programmable architecture that is performance, size and power optimized for the fastest combination of modems available for:
- LTE FDD/TDD (Cat3)
- 3G (DC-HSPA+ Cat 24)
- EV-DO Rev. B
- 1x Advanced
- TD-SCDMA
- GSM/GPRS/EDGE NFC.
Multimode/Multiband Means Worldwide Coverage.
• Support for multiple radio frequencies: Mobile broadband technologies are growing increasingly complex in their implementation. LTE is currently being implemented in over 40 diff erent radio frequency bands throughout the world. To complement its wide range of modem standards supported, Qualcomm has designed the Snapdragon S4 Processor MSM8960 CHIPSET platform to <<< address all commonly-used frequencies (from 700–2600 MHz) and bandwidths up to 20 MHz>>>, allowing its customers to address any mobile network opportunity whether the simplest single frequency implementation to the most extensive multi-frequency global mode, whether 4G, 3G or 2G.
-----------------------------------------------------------
Based on the document the chip can handle all LTE Standards, but it depends on his "advanced, programmable architecture"....as written there and how Motorola / Sprint implemented this, maybe they reduced LTE only to one Standard.
I don't have LTE in my area and so I cannot test this.
That's possibly right.
Something else:
If I remember correctly, somewhere in this forum have been said that for CDMA the internal Sprint "ID"(?) is used.
Maybe that's also the reason why I cannot connect to LTE in my area.
The phone is trying to "login" with the Sprint ID and this of course won't work.
The ##DEBUG# menu wasn't helpfull. It shows frequencies for american standards and not for GSM/WCDMA.
Also the LTE menu is also not very helpfull, it doesn't show frequencies at all.
Any News on this topic?
Maybe one of the developers can give a statement?
Yesterday I tested a LTE compatible SIM card.
My Bro has a Samsung Galaxy S4 with 4G/LTE in my area.
So I've put his SIM-Card into my Photon Q and set LTE only.
I had no luck, the Phone couldn't register into the network for this SIM.
I guess either it has the wrong frequencies or LTE is for inbuilt "SIM" (Sprint SIM?) only.
The latter. LTE is configured only for 1900 MHz which Sprint uses.
LTE is configured only for Sprint's frequencies, however, it supports the United States frequencies of PCS blocks A-G. The G Block is Sprint's current LTE channel, and they may deploy it later on Blocks A through F, depending on if they own the spectrum in a given market. The reason you see EU networks when the phone is in LTE Only Mode is most likely because the Phone still sees GSM signals, but will only connect to LTE ones from those GSM signals. Likewise, in the US, if you force LTE Only and then search for networks, AT&T and T-Mobile US will come up as the GSM carriers the Photon Q sees, rather than the LTE signals it sees.
Setting the Photon to LTE Only will not do anything for LTE in the EU. I suspect that if another carrier in the EU uses the 1900 MHz for LTE, the Photon Q will have no issues connecting to LTE in Europe. But until that time, be happy with HSPA.
Skrilax_CZ said:
LTE is configured only for 1900 MHz which Sprint uses.
Click to expand...
Click to collapse
Can this configuration theoretically be changed / other frequencies be added?
Only if you break BP security.
Skrilax_CZ said:
Only if you break BP security.
Click to expand...
Click to collapse
Sorry, what's that?
IIRC The only place with 850mhz LTE available is the Chicago market and currently no phones at all support it. :crying:
Not only does your phone need to support it, your PRL and cell-site does too...
Hi, I have a 64gb OPO in USA on Straight Talk, using AT&T network. For some reason I'm not able to get an LTE signal in Burlington, Vermont area despite LTE service being available locally. As soon as I cross into New York, New Jersey, or other states I can and do receive LTE signal, so I know my device and Sim card are capable. Others have told me AT&T uses an unconventional LTE band in this area because they took over another carrier called Unicel. What I need help determining is what band they use locally and subsequently which radio I need to flash to get LTE on that band. Currently my battery drains fast constantly switching from hspa to hspa+, yet doesn't do so in other cities and states. Any help, and links are greatly appreciated.
The OPO hardware LTE bands are: 1, 3, 4, 7, 17, 38 and 40. ATT US uses bands: 2, 4, 5, 17. So, if your ATT LTE signal is on 2 or 5 you won't get LTE in that area on your OPO. The bands are a hardware limitation of the OPO and can't be unlocked, as some people have tried in this thread: http://forum.xda-developers.com/showpost.php?p=56577252&postcount=455.