Develop Bugs

ARC 3G compatibility

i bought this ARC from hongkong and now im in canada
but i never found the 3G network, and then i go to Fido store
i changed a SIM card.But nothing change.
and finally i found the problem: My Lt15i is only support UMTS/HSPA 900/2100
And i wanna to know if i can fix by change CDA or the driver of baseband?

no way to change the band compatibility... it's hardware related. your best bet is to sell that one and buy the arc from rogers

I had the same issue. I did receive the LT15i so it only works on EDGE.
eBAY is going to refund the money when I return the phone
I will then buy a LT15a which will work on our bands.

I'm amazed you don't know this. You buy a Hong Kong phone or a European phone, it is not 3G Canada. Hey, this is XDA. This is where they're supposed to know.

Here's a pro tip regarding Sony Ericsson phones.
last letter a = North American GSM frequencies (850/1900/2100)
last letter i = Global GSM frequencies (900/1800/2100)
last letter c = Chinese GSM frequencies and may be TD-SCDMA​
LT15a is Xperia Arc for AT&T/Rogers/Fido/Bell/Telus frequencies.
LT15i is Xperia Arc for Europe, Asia, Africa and Australia GSM frequencies.
SO-01C is Xperia Arc for Japan.
Is there an LT15c?
What about Brazil?

TWiTCommander said:
What about Brazil?
Click to expand...
Click to collapse
Brazil uses the "a" version.

I'm just wondering to the OP what did you do?
I realize I have the same problem.
I too bought an arc in hong kong. Actually it was meant for my mother, but I traded her with my x10.
My arc LT15i network only works on edge.
I think it's funny how my x10 works great in hong kong while the arc can't connect to 3g here.
Is there a service provider that would be in that same frequency?
I'm currently with fido.
[Edit] Excuse me for reviving dead post.

Switch to LT15a_3.0.1.A.0.145_NAM
maybe works
Here in Brazil, works with LT15a
But works LT15i
But if 3G is hardware problem, I'm sorry!
Greetings

Do not buy a internation version phone unless u clearly know the phone 3g band. It is because most of the international version wont work in most of the carrier in north america. I believe it is because frequency 850 only used in north america, so they have to make a "special" edition for north america carrier.
Also you can't change the baseband to get the 3g network, since it is hardware problem, not software.

LT15i vs LT15a firmwares

Does it matter which firmware runs on which phone?
For example, running LT15i firmware on LT15a, or LT15a firmware on LT15i?
We know the radio ability is different on both phones, would that cause an issue?
Does using a wrong FW disable some radio abilities?

yuanmav said:
Does it matter which firmware runs on which phone?
For example, running LT15i firmware on LT15a, or LT15a firmware on LT15i?
We know the radio ability is different on both phones, would that cause an issue?
Does using a wrong FW disable some radio abilities?
Click to expand...
Click to collapse
Yes it does matter. I think you can still use it because they have the same GSM bands.
BUT you cannot use 3G or HSPA if you use the wrong firmware. LT15i and LT15a have different 3G bands. Better check what your network provider is utilizing.
Or check the cellphone shops whether they sell the i type or the a type.
LT15i = UMTS HSPA 900 (Band VIII), 2100 (Band I)
LT15a = UMTS HSPA 800 (Band VI), 850 (Band V), 1900 (Band II),
2100 (Band I)
The UMTS bands are provided in the white paper of arc at SE developer world site.

i have a rogers branded LT15A and i flashed it with the generic firmware for the LT15i and 3g works fine. so far so good. when i used to have the x10 it ran fine with either version of software. i am not saying that there couldnt be an issue, just not one that i have had that i can directly attribute to using the international software instead of the north american one

zangetsu2188 said:
Yes it does matter. I think you can still use it because they have the same GSM bands.
BUT you cannot use 3G or HSPA if you use the wrong firmware. LT15i and LT15a have different 3G bands. Better check what your network provider is utilizing.
Or check the cellphone shops whether they sell the i type or the a type.
LT15i = UMTS HSPA 900 (Band VIII), 2100 (Band I)
LT15a = UMTS HSPA 800 (Band VI), 850 (Band V), 1900 (Band II),
2100 (Band I)
The UMTS bands are provided in the white paper of arc at SE developer world site.
Click to expand...
Click to collapse
I think firmware interchangeability is a one way deal for the LT15i and the LT15a, in the sense that you can flash an LT15i ROM on your LT15a device and still use 3G (I'm on rogers, and 3G works), but flashing a LT15a ROM onto a LT15i will not give you the 3G bands of the LT15a

I also flashed my Rogers LT15a with the LT15i 2.3.3 World Generic firmware
All running fine

zangetsu2188 said:
Yes it does matter. I think you can still use it because they have the same GSM bands.
BUT you cannot use 3G or HSPA if you use the wrong firmware. LT15i and LT15a have different 3G bands. Better check what your network provider is utilizing.
Or check the cellphone shops whether they sell the i type or the a type.
LT15i = UMTS HSPA 900 (Band VIII), 2100 (Band I)
LT15a = UMTS HSPA 800 (Band VI), 850 (Band V), 1900 (Band II),
2100 (Band I)
The UMTS bands are provided in the white paper of arc at SE developer world site.
Click to expand...
Click to collapse
Are you sure about this?
I just too, like the above two posters, flashed a world generic LT15i to LT15a and working fine on Rogers.
According to Wiki, rogers UMTS is operating on 850 and 1900 bands, both not supported by LT15i.
Is there something hidden in the drivers etc?

Working bands shown under *#*#7378423#*#*
GSM: 850 900 1800 1900
UMTS: BC1 BC2 BC5 BC6

yuanmav said:
Are you sure about this?
I just too, like the above two posters, flashed a world generic LT15i to LT15a and working fine on Rogers.
According to Wiki, rogers UMTS is operating on 850 and 1900 bands, both not supported by LT15i.
Is there something hidden in the drivers etc?
Click to expand...
Click to collapse
This is somewhat confusing. I used Xperia X8 before going to Xperia arc.
They mentioned that flashing the i or a version incorrectly will make 3G connection not possible (http://forum.xda-developers.com/showthread.php?t=875688)
I didn't even try to flash the a version before because my network provider is using the 2100 MHz band for UMTS (2100 frequency is present in the two versions)
I've checked Rogers wireless and noted that the network is indeed using 850/1900 bands for UMTS. Kinda weird that LT15i firmware is working.

It shouldn't matter what firmware you flash onto your phone.
Since v2.1, all firmwares have included the software portion of both "i" and "a" radios meaning you can run any firmware on any phone. (However, this DOESN'T mean that flashing an "i" firmware onto an "a" phone will give it "i"-frequency 3G when in an "i" coverage zone and vice versa. The hardware is what determines what 3G frequencies the phone is capable of handling and that is fixed.)
It's how people are already flashing the latest 2.3.3 update on North American arcs.
Make sure that you enter in your APN settings correctly once flashed. I've never had issue running any ROM and getting 3G data connectivity.

BluechipJ said:
It shouldn't matter what firmware you flash onto your phone.
Since v2.1, all firmwares have included the software portion of both "i" and "a" radios meaning you can run any firmware on any phone. (However, this DOESN'T mean that flashing an "i" firmware onto an "a" phone will give it "i"-frequency 3G when in an "i" coverage zone and vice versa. The hardware is what determines what 3G frequencies the phone is capable of handling and that is fixed.)
It's how people are already flashing the latest 2.3.3 update on North American arcs.
Make sure that you enter in your APN settings correctly once flashed. I've never had issue running any ROM and getting 3G data connectivity.
Click to expand...
Click to collapse
you beat me to it. you are correct

Do you think that this would work for a Neo (MT15i) phone too?
(would be a bless as f/w patches are more quickly available for the arc)

Just bought Xperia arc LT15A but when I check phone version it says LT15I. So i called the seller and im told that it was flashed with LT15I firmware thats why its showing as LT15I. Is that possible that it will show as LT15i? Box shows lt15a by the way and im a little confuse. Also what are the settings for APN I will be using it with Rogers network (data/mms). Thanks in advance.

jon3sh said:
Just bought Xperia arc LT15A but when I check phone version it says LT15I. So i called the seller and im told that it was flashed with LT15I firmware thats why its showing as LT15I. Is that possible that it will show as LT15i? Box shows lt15a by the way and im a little confuse. Also what are the settings for APN I will be using it with Rogers network (data/mms). Thanks in advance.
Click to expand...
Click to collapse
Yep, flashing a LT15i firmware on a LT15a will change the name under "about". This is normal and should not affect the functionality of your phone. Rogers APN below:
Name: Rogers Internet
APN: rogers-core-appl1.apn
Proxy: Not Set
Port: Not Set
Username: Not Set
Password: Not Set
Server: Not Set
MMSC: http ://mms.gprs.rogers.com
MMS proxy: 10.128.1.69
MMS port: 80
MCC: 302
MNC: 720
APN Type: Not Set

Thanks pre I cant wait to add tweaks and apps to this phone.

LT18i vs LT18a

Whats the difference between the LT18a and the LT18i?

a is for use in the USA, i is international.
Sent from my LT15i using XDA Premium App

dows anyone knows if the LT18i has HSDPA 850 band? GSMArena says it doesn't but newegg and sony's site say it does.

sony know the best, they are creators.
LOOK THIS AT THE BOTTOM OF GSMARENA
Disclaimer. We can not guarantee that the information on this page is 100% correct. Read more

from sony whitepapers
LT18i: UMTS HSPA900,2100 GSM GPRS/EDGE 850,900,1800,1900
LT18a UMTS HSPA800,850,1900,2100 GSM GPRS/EDGE 850,900,1800,1900
look like LT18a is US version

a= america = 850MHz 3G
i= international = 900MHz 3G, but also uses 850 for GSM only (it works on america but with slow internet(GSM))

can u guys help me?
I got one lt18a but won't work 3g, because the frequency network.
Can I change it or something like that? like firmware? thanks.

eugnasblood said:
can u guys help me?
I got one lt18a but won't work 3g, because the frequency network.
Can I change it or something like that? like firmware? thanks.
Click to expand...
Click to collapse
Nope. The radio is hardware and fixed.

xperia arc s lt8a
eugnasblood said:
can u guys help me?
I got one lt18a but won't work 3g, because the frequency network.
Can I change it or something like that? like firmware? thanks.
Click to expand...
Click to collapse
I too just got my xperia arc slt18a and got straight talk as my tmobile affiliate pay as you go didnt work cuz it doesnt have the 1700 frequency to get the 3g but when i do the speed test app it says im only getting .01 mbs download and 2.1 upload speed

LT18a vs LT18i - HSDPA 2100 band
Hi friends,
I am looking to buy SE Arc S in USA and want its 3G/HSDPA feature to work in India also. Mostly internet surfing I will do in India and seldom in USA.
HSDPA bands supported by both models is as below:
HSDPA 900 / 2100 - LT18i
HSDPA 850 / 1900 / 2100 / 800 - LT18a
Both LT18a and LT18i operate on 2100 band for HSDPA. Is there any form of difference when Sony claims support for band 2100 HSDPA in LT18a vs LT18i OR are the hardware radio/frequency & firmware/driver exactly same for 2100 band in both models.
In India 3G/HSDPA runs on 2100 band. I am confused which one to go for.
Please provide inputs.
Thanks in Advance

Friends,
I need to buy SE Arc S pretty soon. Please provide inputs about above query abt band 2100 HSDPA.
Thanks alot

technosavyy said:
Friends,
I need to buy SE Arc S pretty soon. Please provide inputs about above query abt band 2100 HSDPA.
Thanks alot
Click to expand...
Click to collapse
I have a lta and there is no issue with 3g.
Sent from my LT18i using Tapatalk 2

finch.****break said:
I have a lta and there is no issue with 3g.
Sent from my LT18i using Tapatalk 2
Click to expand...
Click to collapse
Thanks. Are you using SE Arc S LT18a in India on 2100 band.
I know that LT18a will work well in USA on 2100 HSPA band, and in India also we have 3G running on 2100 band. So will in my case LT18a run on 3G seemlessly well in India as well?

[Q] Lt18i 3G can not work in Mexico

I bring my Lt18i from China to Mexico, only GSM is working normally, can not attach to WCDMA network.
I know the WCDMA frequency is different, China is 850 Band1/2100, Mexico is 850 Band2/1900.I do not know if this feature is fixed by hardware or software.
Is there any solution i can use WCDMA network in Mexico?

Still no reply,
Anyone can provide a Mexico ROM, i can try it.

Yes, buy a LT18a
Sent from my iPad 2 using Tapatalk

GSM Defy can change frequency bands!

Hi everyone,
It's always been known that there is a 900/2100 Defy and an 850/1900 Defy.
I got mine from my 850mhz carrier in Australia. I am visiting Hong Kong at the moment. I purchased a one2free SIM (900mhz network), changed my baseband, and got on data with full HSPDA! I can download around 200kbytes a second.
Thought I'd share for fellow travellers.
Sent from my MB525 using XDA

Hi, how did you change the basebands to HDSPA 850/1900?

Look up "baseband switcher for defy" in Google. You'll be surprised. It's not really news...

Thanks for your answer, but I have a Defy+ with cm7. I tried with basebandswitcher and baseband of cyanogen but didn't work, they didn't change frequencies and the phone lost signal. Do you know why? Thanks