GPRS blocks incoming calls, bug in Radio stack

[oberkeller]

Just a heads-up

I have had the Vox for a couple of weeks here in Sweden

It is being used with Active sync towards an Exchange 2003 over GPRS

I quickly noticed that suddely it was not possible to receive SMS or incoming calls, the calls just got redirected to voicemail, after a reboot the phone started working for a while again, but it kept coming back.

After a couple of discussions with HTC and the distributor (and 2 rounds to the service partner for more extensive tests only to say that the phone was fully functional...) I now know what the problem is, and I put it here to let you know.

Aparently here in sweden and the rest of the nordic coutries we use GPRS type B
See here for a spec:
http://www.gsmworld.com/technology/gprs/class.shtml
(http://www.gsmworld.com/technology/gprs/class.shtml)

And the radio stack in S710 has trouble switching between GPRS and GSM

What they told me is that HTC are working on this, (and they better be and fast...), because without a fix GPRS is useless on this phone it could anytime hang in either GPRS or GSM mode, resutling in nonworking GPRS or (even worse) no GSM, you only notice this on the fact that incoming calls are not working, outgoing calls works.

So the only way to test is constantly call your own phone to see if it is still working.

The only fix I have found to this so far is to disable all GPRS accounts and reboot the phone...

Just thought I should share this information with you. I have a feeling that more people will experience this, and I had to do a lot of digging to get this information.

If someone else has some more information or experienced this I would love to hear about it.

[kast]

Thanks for the tip.
Got my S710 yesterday evening, did the GRPS setup today afternoon and tonight got couple of calls redirected to voicemail... Yep GPRS was on (although I wasn't actually doing anything, just noticed the "E" icon for an active connection). Thought was only bad reception... Knew about the missed calls because of the SMS telling me right away somebody had called.
Anyhow, SMS were getting in... Maybe it's not related to the same problem... Hopefully was really only bad reception, but enough reception for SMS.

I'll do some more testing tomorrow. I can't afford missing work calls or I know I'm fired by listening my voicemail.

Thanks,
Ka.

[pinussen]

Ok, time to disable the GPRS settings... Let's hope they make a bugfix soon for this.

[colonel]

thats really worrying. has anyone experienced this in the UK ?

The whole point of the S710 is so I can have IM and push email and phone on one tiny device with keyboard

[oberkeller]

I think this is all related to the GPRS class B, what I understand so far at least is that this is mainly a problem in the nordic counties where this is used (I may very well be misinformed, this is new to me, I have a diploma in GSM technologies from a short course but that is not even worth the paper anymore :D )

If a network uses Class A, this is what I am told not a problem, and Class C seems mostly useless everywhere, look at my link in my first post and read about Class C ,you will see why :)

Kast, that sounds like a slightly different problem, I don't get SMS or calls when this happens, you also have access to EDGE and that may not have the same problem (don't know). But it would either way be interresting to see if you experience problems.

[shto]

The class of GPRS (class B) is parameter no to gsm provider. This is spesification on device htc s710.
I have also htc s620. Result of my testing is that this device is working on Gprs Class B. When i made sinhronzation to exchange server then you can't call my gsm number, but when my sinhro is done you can call my gsm.

The bug on htc s710 is very serios i hope that from htc make quickly patch or update to solve it !

[colonel]

definitely all working fine on my new S710 in the UK. Will be trying in NY next week .....

[oberkeller]

Yes I think the problem is definately in Tele2's network in Sweden but probably also the other networks hera as well as in Denmark, Norway and Finland
That is what I've been told anyway. But thanks for the info

[motin]

gd day friends

have just tried this issue on a orange il simcard and no problems were found

i can get calls and sms while gprs is on !

thanks

[oberkeller]

Then orange has GPRS class A (I wish they had that in sweden as well then we would not have that problem here...)

[WDawn]

I have the same problem with a HTC Tytn in Belgium with Proximus, whenever the GPRS connections is enabled, calls tend to be blocked and go directly to my voicemail. Only fix is to disable the GPRS connection and only use it to check your mail every hour or so.

[rhedgehog]

If I remember rightly, All GPRS phones are class B anyway. Never come across a class A GPRS handset yet (or if i have, it was never plugged as a class A device).

what tends to happen is that the network and the phone will negotiate to suspend the GPRS connection when there have been no packets sent for a certain amount of time to save the power on the handset and the towers, and to optimise the bandwidth to accomodate as many users as possible.

Seems your network might have this suspend timeout set a little too high, or alternatively, I suppose the network infrastructure could be Class B and therefore not support it at all.

I'm sure there was a reg hack around for earlier smartphones to make the GPRS connection disconnect automatically after 30 seconds or so. seems you might have to set activesync to check avery so often and see if you can find this hack.

ubfortunately, this is always going to be an issue on GPRS/EDGE devices if you are a heavy email user....but the networks still want the handsets, so they will still be made.

[oberkeller]

Hi,
I donät think the problem is with the network timeout, I have used the similar setup with Nokia handsets and Sony-ericsson and the correctly suspend the GPRS and then resume it after a finished call. But this phone seems to hang in the GPRS mode, then network is trying to send the call to the phone but the phone is not able to pick it up.

I think you are right that the registry hack might help, have not tried that yet, don't know if it is the same in WM6 either. But I might give it a try, now I have solved it via WLan at work and no e-mail elsewhere :-/

[oberkeller]

Did a bit of testning with the registry keys found this thread (http://forum.xda-developers.com/showthread.php?t=305332&highlight=gprs+disconnect+registry)
And changing the first key

DWORD CacheTime
60 - Timeout in seconds
String SuspendResume
~GPRS! - Always On
GPRS_bye_if_device_off - Timeout after CacheTime

This works, setting the timer to 30 seconds automatically disconnects the GPRS session, next is to see if the phone stops receiving calls or if it still works even with GPRS activated... Let¨s keep out fingers crossed

[oberkeller]

The registry edit seems to solve the problem at least eough for me to receive e-mail at scheduled times and receive calls.

However this is not a final solution, still waiting for a radio update from HTC...

And there is always a risk that the phone stops working during the rime GPRS is active...

[pocketboy]

I have a s710 also. I'm having missed calls very often, people are complaining they can't reach me. Sometimes after a certain period a sms arrives that i haved missed calls.
I use GRPS constantly due to the syncing with exchange (push mail) at my work.

Is there a solution for this problem yet?

[jockyw2001]

You should try the radio in the Arabic rom (do a search).
It's the latest version.

[jdhelstrom]

After much experimentation, i have found the following:

1. If i boot up my phone WITHOUT the USB cable attached, and i start transferring data from the internet, my phone will not allow any incoming calls. They all get sent to voicemail.

2. If i boot up my phone WITH the USB cable connected (which happens to block GPRS data), but THEN DISCONNECT the USB cable so i can activate a GPRS connection, when I start transferring data from the internet to my phone, it will pause the data transfer and allow incoming calls to ring through to the phone.

[MR2046]

My company has C500 ( Vox in Asia named Dopod C500 ). We suffer from the same problem that everyone in this thread are talking about....hang and incoming calls blocked. The only way to solve is romove the battery to reset it.

HTC Thailand gave us the -new hope- ROM which I believe it was modified from the Arabic ROM. But no improvement.


Anyone get the solution?

MR2046 T_T

[prajith]

on my S710 i can receive calls but the caller cannot hear me.
but when i make a call its perfect.
I am tired of making callbacks, somebody pls help :(