13 thoughts on “LE910-EUG Fail to camp on 3G after frequency band selection”
AT command reference stats that I can select certain frequency band using AT#BND=GSM,WCDMA,LTE so I made the module to use 3G only using: AT+COPS=1,2,”60201″,2 Then I used the command: AT#BND=0,0,80044 to select B1(2100MHz) in 3G The module’s LED keep ON without flashing and the module doesn’t camp to the network and gives me: +COPS=1 After that I send to the module AT#BND=0,18,8004 for default settings and the module’s LED keep ON When I check COPS it still 1 Then I initiate AT+COPS=0 then check it so it’s value is 0 and when initiate AT+COPS=? The module’s LED start Flashing but the answer I receive is: +COPS: (2,”Mobinil”,”Mobinil”,”60201″,0),(1,”Etisalat”,”Etisalat”,”60203″,0),(3,”vodafone EG”,”voda EG”,”60202″,0),,(0,1,2,3,4),(0,1,2) As you can see the module doesn’t see any 3G network! Now how can I use 3G only or 4G only and camp on certain frequency band correctly?
bump
I’ve a project in Canada and I already purchased 1 x LE910-EUG and 3 x LE910-NAG and I must finish early so seriously does this problem has a solution and if not does it apply on LTE too? I’m waiting for your kind answer
Another question, is it preferable to select the network type using AT+COPS or AT+WS46? And what’s the difference between them both?
I solved the frequency problem but I need someone to confirm on what I discovered cause I’m not an expert in Network Bands. I set the AT+COPS to manual 3G on operator 60201, then I initiated AT#MONI to get the serving cell, after that I got the UARFCN and convert it to a frequency using an online calculator. I found that the module is working on 3G in 900MHz band, so I set the 3G band to work only on 900MHz band using AT#BND=0,5,80044. The module now is working on 3G only on 900MHz band only! To understand why it didn’t work on 2100MHz band, I asked one of my colleagues who involved on RF planning about this issue, he educated me that due to 3G uses scrambling codes unlike GSM, so the operator never uses 2 frequency carriers in same area except if it’s a very crowded area which made the operator to finish its scrambling codes, at this moment and in this area the operator adds another frequency band to give the users another set of scrambling codes. From this I understand that my area is working in 900MHz band on 3G, is that right from your point of view?! Another thing, why the module when I go to 2100MHz then back to B18 or even 900MHz band and I’m forcing it to 3G only using AT+COPS, it camps on GSM network?!! How could that happen?
Setting AT+COPS=1,2,”xxxyy”,2 you do not force the module to work in 3G only mode. You force the module in manual selection to NW operator xxxyy and WCDMA technology. It doesn’t mean that when 3G is no more available the module won’t get registered, but it will search for the same xxxyy operator in 4G (preferable) or 2G.
If you want really force the module to work in 3G only you have to set AT+WS46=22. In this way the module will not scan for 2G or 4G frequencies.
Thank you very much!
In addition to Andrea’s answer:
It isn’t recommended to handle the bands unless you are completely aware of the consequences it might cause: registration problems, disconnections, etc.
To use 3G only networks – AT+WS46=22
To use 4G only networks – AT+WS46=28.
I know about registration problems, it happened with me before, so each time I change the band I check for network registration first either using AT+CREG or AT+COPS, but after a while if it’s not registered I change the band again cause the first band might be not used, if the proeblem is still exists, then I either re-change the technology or restart the module.
Please, advise me if I’m wrong.
As I wrote previously, you should not change the bands.
The module has a set of frequencies/bands for each technology.
When the module powers up, it start scanning the frequencies/bands that correspond to the technology you chose with AT+WS46 command.
So what you need to do it to chose the technology you want to work with:
– AT+WS46=22 for 3G
– AT+WS46=28 for 4G
– AT+WS46=25 for both 3G and 4G
and then use AT+CREG or AT+COPS (as you wrote) to wait for completing the registration.
The only reason I can think of to change the bands is when registration process takes a long time and you want to narrow the search. but you must know what frequency to use.
As I wrote previously, you should not change the bands.
The only reason I can think of to change the bands is when registration process takes a long time and you want to narrow the search. but you must know what frequency to use.
Don’t worry, I already know the operator’s bands there, so when I start searching using certain band in certain technology, I’m sure that either the band is available but not used in this area (I’ll know that as the module won’t register) or the module will register to the network successfully, in both cases I’ll not use any band isn’t used by the operator or even by the module part number itself!
As I wrote previously, you should not change the bands.
The module has a set of frequencies/bands for each technology.
When the module powers up, it start scanning the frequencies/bands that correspond to the technology you chose with AT+WS46 command.
So what you need to do it to chose the technology you want to work with:
– AT+WS46=22 for 3G
– AT+WS46=28 for 4G
– AT+WS46=25 for both 3G and 4G
and then use AT+CREG or AT+COPS (as you wrote) to wait for completing the registration.
The only reason I can think of to change the bands is when registration process takes a long time and you want to narrow the search. but you must know what frequency to use.
Using AT#BND make some result give invalid data, as it gives that network is working on a certain band while these band is not operated in these Country!!!
In Egypt, there is no UMTS 850 MHz operated and Telit LE910-EUG give me after certain sequence in the following dialoge that there are a registered network ??!!
ATE1 OK AT+CGSN 359852050016261
OK AT#CIMI #CIMI: 602022168159425
OK AT+CCID ERROR AT#BND=? #BND: (0),(0,2,5,6,8,9,12,16,18,20),(80044)
AT command reference stats that I can select certain frequency band using AT#BND=GSM,WCDMA,LTE so I made the module to use 3G only using:
AT+COPS=1,2,”60201″,2
Then I used the command: AT#BND=0,0,80044 to select B1(2100MHz) in 3G
The module’s LED keep ON without flashing and the module doesn’t camp to the network and gives me:
+COPS=1
After that I send to the module AT#BND=0,18,8004 for default settings and the module’s LED keep ON
When I check COPS it still 1
Then I initiate AT+COPS=0 then check it so it’s value is 0 and when initiate AT+COPS=? The module’s LED start Flashing but the answer I receive is:
+COPS: (2,”Mobinil”,”Mobinil”,”60201″,0),(1,”Etisalat”,”Etisalat”,”60203″,0),(3,”vodafone EG”,”voda EG”,”60202″,0),,(0,1,2,3,4),(0,1,2)
As you can see the module doesn’t see any 3G network!
Now how can I use 3G only or 4G only and camp on certain frequency band correctly?
bump
I’ve a project in Canada and I already purchased 1 x LE910-EUG and 3 x LE910-NAG and I must finish early so seriously does this problem has a solution and if not does it apply on LTE too?
I’m waiting for your kind answer
Another question, is it preferable to select the network type using AT+COPS or AT+WS46? And what’s the difference between them both?
I solved the frequency problem but I need someone to confirm on what I discovered cause I’m not an expert in Network Bands.
I set the AT+COPS to manual 3G on operator 60201, then I initiated AT#MONI to get the serving cell, after that I got the UARFCN and convert it to a frequency using an online calculator.
I found that the module is working on 3G in 900MHz band, so I set the 3G band to work only on 900MHz band using AT#BND=0,5,80044.
The module now is working on 3G only on 900MHz band only!
To understand why it didn’t work on 2100MHz band, I asked one of my colleagues who involved on RF planning about this issue, he educated me that due to 3G uses scrambling codes unlike GSM, so the operator never uses 2 frequency carriers in same area except if it’s a very crowded area which made the operator to finish its scrambling codes, at this moment and in this area the operator adds another frequency band to give the users another set of scrambling codes.
From this I understand that my area is working in 900MHz band on 3G, is that right from your point of view?!
Another thing, why the module when I go to 2100MHz then back to B18 or even 900MHz band and I’m forcing it to 3G only using AT+COPS, it camps on GSM network?!! How could that happen?
Setting AT+COPS=1,2,”xxxyy”,2 you do not force the module to work in 3G only mode. You force the module in manual selection to NW operator xxxyy and WCDMA technology. It doesn’t mean that when 3G is no more available the module won’t get registered, but it will search for the same xxxyy operator in 4G (preferable) or 2G.
If you want really force the module to work in 3G only you have to set AT+WS46=22. In this way the module will not scan for 2G or 4G frequencies.
Thank you very much!
I know about registration problems, it happened with me before, so each time I change the band I check for network registration first either using AT+CREG or AT+COPS, but after a while if it’s not registered I change the band again cause the first band might be not used, if the proeblem is still exists, then I either re-change the technology or restart the module.
Please, advise me if I’m wrong.
Don’t worry, I already know the operator’s bands there, so when I start searching using certain band in certain technology, I’m sure that either the band is available but not used in this area (I’ll know that as the module won’t register) or the module will register to the network successfully, in both cases I’ll not use any band isn’t used by the operator or even by the module part number itself!
Using AT#BND make some result give invalid data, as it gives that network is working on a certain band while these band is not operated in these Country!!!
In Egypt, there is no UMTS 850 MHz operated and Telit LE910-EUG give me after certain sequence in the following dialoge that there are a registered network ??!!