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Mobile Network mode GSM/CDMA confusion *#*#4636#*#*

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andQlimax

Senior Member
Jul 29, 2010
2,559
1,003
Rome
Entering in the "secret" menu *#*#4636#*#*, i noticed that the default network mode is GSM/CDMA auto (PRL)

Aren't two completely different networks (and phone)? Or what that CDMA setting is referring?

Since my GNext is GSM and in my country there is no CDMA network operators, is that the best option regarding the battery life?

I remember that in my previous htc desire, the default network mode was WCDMA preferred (WCDMA different from CDMA), even if i was using GSM auto (PRL) which mean that if the 3g is low it will use the 2g network...and i remember there was nothing about CDMA network

So my doubt is why the Galaxy Nexus GSM doesn't have GSM auto (PRL) or WCDMA preferred as default option? is that a bug?

here a reference about the network mode http://www.google.ie/support/forum/p/android/thread?tid=6a327a95211ac789&hl=en

GSM = GPRS (2g), EDGE(2g), UMTS(3g), WCDMA(3g), HSDPA(3g) {Cell Carrier examples: AT&T and T-Mobile}
CDMA = CDMA*(2/3g) EV-DO(3g) WiMax(3/4g) {Cell Carrier examples: Verizon and Sprint}

Now that the general stuff is out of the way, here's my take on the Preferred Network types:

WCDMA preferred - The GSM phone is capable of using both 2G and 3G data communication and when signal strength is low 3G is favored more.
GSM only - The GSM phone is capable of using only 2G data communication. When the 2G signal is too low you get nothing at all.
WCDMA only - The GSM phone is capable of using only 3G data communication. When the 3G signal is too low you get nothing at all.
GSM auto (PRL) - The GSM phone is capable of using both 2G and 3G data communication and when signal strength is low 2G is favored more. This one is a bit confusing to me since PRL is associated mostly with CDMA technology and not GSM technology.
CDMA auto (PRL) - The CDMA phone is capable of using both 2G and 3G data communication and when signal strength is low 2G is favored more.
CDMA only - The CDMA phone is capable of using only 2G data communication. When the 2G signal is too low you get nothing at all.
EvDo only - The CDMA phone is capable of using only 3G data communication. When the 3G signal is too low you get nothing at all.
GSM/CDMA auto (PRL) - Some phones are equipped with both GSM and CDMA capabilities. This setting appears to just have the phone attempt to stay connected to the data communication type that works the best.

In addition seems there is no way to change the network mode in that menu on my gnext, the option i choice doesn't stick
 

yiannisthegreek

Senior Member
Jul 2, 2009
1,996
256
Edmonton
Entering in the "secret" menu *#*#4636#*#*, i noticed that the default network mode is GSM/CDMA auto (PRL)

Aren't two completely different networks (and phone)? Or what that CDMA setting is referring?

Since my GNext is GSM and in my country there is no CDMA network operators, is that the best option regarding the battery life?

I remember that in my previous htc desire, the default network mode was WCDMA preferred (WCDMA different from CDMA), even if i was using GSM auto (PRL) which mean that if the 3g is low it will use the 2g network...and i remember there was nothing about CDMA network

So my doubt is why the Galaxy Nexus GSM doesn't have GSM auto (PRL) or WCDMA preferred as default option? is that a bug?

here a reference about the network mode http://www.google.ie/support/forum/p/android/thread?tid=6a327a95211ac789&hl=en



In addition seems there is no way to change the network mode in that menu on my gnext, the option i choice doesn't stick

Id like to know why the options dont stick as well... Just seems stupid to me that they dont stay after you choose them.
 

GrandMstrBud

Senior Member
Jan 30, 2007
1,345
84
I have also been wondering the same thing. On the Nexus One and Nexus S it would default to WCDMA prefered and if I were to force 3G on it then it would stick on a reboot. On the GN if I put it to WCDMA only or GSM only it will revert to the GSM/CDMA auto (PRL) network type. It did this on stock 4.0.2 and it's also doing it on CM9.
 

3bs11

Senior Member
Mar 1, 2012
1,049
243
Dublin, Ireland
GSM auto (PRL) won't stick but WCDMA did for me but I REALLY regret changing it. It caused my SMSC number to change to 00 and I couldn't change it back on my GNex. It took me a while to figure out that the SMSC had changed and it stopped me from sending text messages but I could still receive them. After wiping and flashing a few times I realised and I put the sim card into an old phone and changed the SMSC back and put it back in my GNex and it let me send texts again.
 

The Gingerbread Man

Senior Member
Sep 4, 2010
8,097
3,945
Gloucester
GSM auto (PRL) won't stick but WCDMA did for me but I REALLY regret changing it. It caused my SMSC number to change to 00 and I couldn't change it back on my GNex. It took me a while to figure out that the SMSC had changed and it stopped me from sending text messages but I could still receive them. After wiping and flashing a few times I realised and I put the sim card into an old phone and changed the SMSC back and put it back in my GNex and it let me send texts again.

I am going to eat my own words but iv just done the same thing, can't send SMS. I don't have an old phone to put my sim in. I'm not sure what my SMSC was to change it back. Ideas?

Sent from my Galaxy Nexus using Tapatalk
 

3bs11

Senior Member
Mar 1, 2012
1,049
243
Dublin, Ireland
I am going to eat my own words but iv just done the same thing, can't send SMS. I don't have an old phone to put my sim in. I'm not sure what my SMSC was to change it back. Ideas?

Sent from my Galaxy Nexus using Tapatalk

God it was a nightmare yesterday. I did a google search and found the number on vodafone forums for my country. What's your carrier? Even if you have the number maybe you won't be able to put it on your nexus like me but you can try. Another possible solution might be to get a new sim card but I'm not sure if that'll work. I just read it online.

Sent from my Galaxy Nexus using Tapatalk
 
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3bs11

Senior Member
Mar 1, 2012
1,049
243
Dublin, Ireland
Apparently not. The annoying thing is there is thing OEM specific carrier info button which is greyed out, I bet that would sort out my settings.

Sent from my Galaxy Nexus using Tapatalk


Mine is greyed out too so maybe that doesn't change anything in this case. I guess your best bet is trying to put the sim card into another phone and set the SMSC number on that phone then plug it back into your GNex. I used an old blackberry
 

The Gingerbread Man

Senior Member
Sep 4, 2010
8,097
3,945
Gloucester
Mine is greyed out too so maybe that doesn't change anything in this case. I guess your best bet is trying to put the sim card into another phone and set the SMSC number on that phone then plug it back into your GNex. I used an old blackberry

Yeah, might be borrowing my mums Nokia at this rate lol Did you find if you tried to copy and paste numbers into the smsc area it caused a force close for 'phone'?

I did come across http://smsclist.com/downloads/default.txt which looks pretty handy to have around

Sent from my Galaxy Nexus using Tapatalk
 

3bs11

Senior Member
Mar 1, 2012
1,049
243
Dublin, Ireland
Yeah haha I'm sorted now anyway thanks for your help, I can finally send messages again but had to set the message centre on my mums phone lol I'm relieved!

Sent from my Galaxy Nexus using Tapatalk

Glad to see it worked. I actually went back to stock and rooted again and flashed AOKP and all that just to fix this and then realised all that wasn't necessary lol. I wonder if everyone switching to WCDMA only is having this issue or just us?
 

The Gingerbread Man

Senior Member
Sep 4, 2010
8,097
3,945
Gloucester
Glad to see it worked. I actually went back to stock and rooted again and flashed AOKP and all that just to fix this and then realised all that wasn't necessary lol. I wonder if everyone switching to WCDMA only is having this issue or just us?

Gutted! Mine doesnt want to stick with WCDMA but I'm happier with my phone fully working again. I hope no one else gets this and I'm grateful for your help. I never had this particular problem before and I'm glad I know how to sort it next time if needs be

Sent from my Galaxy Nexus using Tapatalk
 

andQlimax

Senior Member
Jul 29, 2010
2,559
1,003
Rome
SMSC update

for refenrece about the above problem updating the SMSC i found this link

http://community.windmobile.ca/windmobile/topics/nexus_s_smsc_advanced_menu_options

its for the nexus s, but it works also on our galaxy nexus

so basically with our nexus (also other samsung i guess) through the advanced menu *#*#4636#*#*, u can update the SMSC only putting the encoded value like described in the link above

also the important things are the 2 buttons near the SMSC field:
- the first on the left (nearest the field) mean refresh: basically should load ur actual SMSC (sometimes don't work)
- the second on the right (far from the filed) mean update: so it change ur SMCS with the actual value on the field..so be carefully if the field is empty

(in my language the translation of those button are wrong, and both have the same label..thats why im explaining it :))

anyway i suggest to don't play with the *#*#4636#*#* menu at all, unless u have problems

hope this helps some future users :)
 
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tmadekush

Member
Apr 16, 2012
8
0
I need help. Im in the US on AT&T. Im having the same problem sending sms. I can receive them but just cant send them. I think i messed up my smsc. Messing around with*#*#4636#*#*.I dont know what to do. Im running stock rom. Can somebody help me and tell what number need to put in. Im kinda lost. Gsm galaxy nexus in the use on ATT
 

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    I am going to eat my own words but iv just done the same thing, can't send SMS. I don't have an old phone to put my sim in. I'm not sure what my SMSC was to change it back. Ideas?

    Sent from my Galaxy Nexus using Tapatalk

    God it was a nightmare yesterday. I did a google search and found the number on vodafone forums for my country. What's your carrier? Even if you have the number maybe you won't be able to put it on your nexus like me but you can try. Another possible solution might be to get a new sim card but I'm not sure if that'll work. I just read it online.

    Sent from my Galaxy Nexus using Tapatalk
    1
    I am going to eat my own words but iv just done the same thing, can't send SMS. I don't have an old phone to put my sim in. I'm not sure what my SMSC was to change it back. Ideas?

    Sent from my Galaxy Nexus using Tapatalk

    OK try +44-7973100973 for orange uk

    Sent from my Galaxy Nexus using Tapatalk