Hi All,

I'm doing a bit of research about I m facing with my N900, especially here in Pakistan- incoming calls cant reach despite strong signal, and delayed incoming texts.

If you're on 3G you can receive incoming calls and SMS messages while you are in the middle of using 3G data - simultaneous voice and data is part of the 3G UMTS spec. So it should never happen on 3G. Great so far.

However if you are on GPRS (circle) or EDGE (E) the spec does not allow for simultaneous calls and data - if you make an outgoing call an existing data session will be terminated until the end of the call.

But what happens if you're using data on GPRS/EDGE first (browsing a web page, checking maps etc) and an incoming call comes in, will you receive the call or not ? Answer: probably not, depending on the phone network!

I have SIM's for all the major phone networks in Pakistan and I've tested all of them and they ALL go DEAD(i.e. my mobile phone acts as its powered off) while it is using GPRS/EDGE data. Also SMS messages don't go through, and are delayed a considerable amount of time.

This is the same issue as in Iphone for quite some time now. Anyone can test it. Open safari and start loading a large website that will keep the browser busy for some time and let the page start loading. Now ring the phone from another phone. Does it go straight DEAD? Also if possible try sending it text messages during this period and see if they are delayed.

Approximately one minute after closing Safari you should be able to ring through to the phone again. (It takes about a minute for an idle GPRS/EDGE session to be closed)

Can you also please find the value for "Network Operating Mode" for the GPRS network. To do this, go into field test mode by dialing *3001#12345#* from the phone app keypad then pressing call, then go to GSM Cell Environment -> GPRS Information, and scroll down to "Network Operating Mode" and take note of the number, which could be 001, 002, or 003. (Most likely 002)

And other information I've been reading, there is more than one possible mode a GPRS/EDGE phone network can be configured in, 001 and 002 being the most common. In mode 001 if an incoming call occurs during data use the data session will be terminated and the call will come through. In mode 002, the call will go straight DEAD. Apparently most networks still use mode 002!

Not only can this be caused by actively using an app such as safari, but background mail checks and push notifications will cause it as well! So if your phone is lying there unattended and it happens to do it's 30 minute (or whatever) mail check just before someone tries to call you - DEAD!

Coming back to N900, having push notifications enabled is even worse, because it tries to keep an active data session as much as possible, and re-establishes this connection every time the data connection is interrupted.

One good example of this is if you have push notifications active, try making or receiving a call, hang up, and call the phone back within a minute or so of the previous call - DEAD!

The reason is that the GPRS/EDGE connection was interrupted by the first call, so when the call ended the phone immediately tries to re-establish the push data connection, and on a slow connection this takes up to a minute to do and then go idle before the phone can receive another incoming call


Regards,
Saad Gadit

Hi Saad,

Dont know what your issue is but I can receive called on GPS or Edge without any problems

Dear Snaps
Thnks for the quik feedback .. the problem is simple.. wenever the data is on course of uploading, calls don’t get through. Like while signing on skype or other services or maybe when authenticating from my end for PUSH mail.. that’s the time when calls or sms cant get through..

Its a strange issue that Ive never heard of. I can receive calls whenever I do these things. Its a multitasking phone, and Maemo 5 just minimises the current app, for me to take the call. Maybe other users can help you

Snaps: It's not a phone issue but dependent on network settings. It seems many networks around the world keep the data connection open at the price of calls not going through, rather than dropping the data connection to let the call get priority.

saad: What happens if you set the phone to always ask before connecting?

Saad I'm also in Pakistan and facing the same problems on Warid , right now I've discontinued my international roaming and got call waiting activated ( it does not work with Int'l roaming on ) the problem seem to have solved

Dear Schawlaf
Thnks for the kind feedback dude.. sounds a bit dumb.. but wat I get get from ur reply is u activated intl roaming in Pakistan?? Btw m using telenor.. not getting how call forwarding can help (by default, call waiting is already active)

If you have this issue on other phones as well, i'd say the problem lies with your carrier(s), not with the phones.

did you contact one of your telcom companies? maybe they can shed more light on this.

I've noticed this problem when on a 2G network (edge).
Normally the data connection gets dropped and the voice call comes through, but sometimes I just don't get the call.

I think there should be an option to only connect to the internet on 3G. I know you can lock to 3G, but does this prevent incoming calls if there is no 3G connectivity and only 2G?

Fortunately in the UK the 3G/3.5G coverage is pretty good...but it does sometimes (even in the centre of Leeds) drop to 2G

would it be feasable to have an app that disconnects the internet if you go on a 2G link then reconnects on 3G?
ive missed a few calls because of this already and it is becoming annoying.

BTW im with tmobile uk