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HSPA Connection Issues and Questions

Posted: Tue Feb 17, 2009 12:12 am
by daftdog
Since joining Exetel a few weeks ago I have been having a lot of trouble with disconnections. I live near Perth in an area that is supposed to be 2100MHz but seems to be in a dead spot. (One of the reasons for my problems is that I have the wrong modem [E220] and I am in the process of buying the correct one [E169].)
But there are other issues. I notice recently there have been others writing with the same problem: disconnecting and not being able to reconnect for several minutes. Also when I am disconnected the modem is turned off and I have to unplug and replug the modem to get it working again. If I unplug it and replug it straight away then the modem will keep flashing double green (ie searching for a network) but will not find the network or connect. If I leave it unplugged and remove the sim for a 5 to 10 minutes and then replug it will usually find the network and then try to connect. A few minutes later it will disconnect again.
None of this seems to be about hardware as it can happen on my laptop or PC or my (Huawei) router using two different E220 modems; nor does it seem to be software as it happens with Linux, Vista or XP. This also happens in the city as well as my local area.

Now my questions are these:
1. If the connection to HSPA (2100MHz) is lost shouldn't the modem drop back to GPRS instead of turning off?
2. Why is my modem being turned off in the first place? (According to my logs it is turned off by a request from the peer(Optus) eg rcvd[LCP TermReq id=0x2] sent [LCP TermAck id=0x2].)
3. Why doesn't the modem find the network and reconnect straight away when I unplug and replug it?
4. Why would it be necessary to run 'ping' continuously to maintain a connection? Does HSPA Broadband drop out if there is no activity?

Forgive me if these are stupid questions, I am still trying to understand how this technology works.

Re: HSPA Connection Issues and Questions

Posted: Tue Feb 17, 2009 10:23 am
by CoreyPlover
daftdog wrote:One of the reasons for my problems is that I have the wrong modem [E220] and I am in the process of buying the correct one [E169].
There seems to be some general confusion about the E220 specs (http://forums.whirlpool.net.au/forum-re ... 23800.html), but yes: under http://www.huawei.com/mobileweb/en/prod ... .do?id=282 it lists only 2100Mhz HSPA (although 900Mhz does appears under GSM / GPRS frequency) whereas the E169 lists 900/2100Mhz under HSPA.
daftdog wrote:1. If the connection to HSPA (2100MHz) is lost shouldn't the modem drop back to GPRS instead of turning off?
I don't know enough about HSPA, but GPRS is a different technology altogether (2G) as opposed to the HSPA/UMTS (which is 3G). It is possible the modem is designed to drop back to 900Mhz UMTS mode, which is unsupported on the E220
daftdog wrote:4. Why would it be necessary to run 'ping' continuously to maintain a connection? Does HSPA Broadband drop out if there is no activity?
HSPA broadband drops down to UMTS when there is no activity. Again, this may be related to the E220 not supporting UMTS 900Mhz. You can try running a constant ping to (hopefully) establish and retain a HSPA 2100Mhz connection

Regarding the issue of requiring physical unplugging of the device, I don't know what may be causing that but would be curious whether the E169 performs better for you (both in connection / drop outs and USB drivers)

Re: HSPA Connection Issues and Questions

Posted: Tue Feb 17, 2009 9:32 pm
by daftdog
I have tried the 'ping' thing after reading your suggestions in a couple of other posts. It didn't work for me.

However, after reading your reply I have a very different understanding of how this all works. One thing I shall try is setting my modem to GPRS preferred and see if that makes a difference. I don't mind the slower speeds as I am replacing very poor dialup (400bps and constant drop-outs).

I dont think that USB drivers are the issue as I am also using a wireless router and the same thing is happening with that.

I feel that the E169 should solve most of the issues I am having. We shall see. I will update you when I get it. Thanx for your help.

Re: HSPA Connection Issues and Questions

Posted: Thu Feb 19, 2009 7:41 pm
by daftdog
I've had the E169 for a day now and it seems to be working well. Certainly seems to have solved my disconnection problems! (It still occasionally disconnects, twice in 24 hours. It wont reconnect until I unplug it, remove the sim card and replug it, but it then reconnects straight away; no waiting. I can live with that for now.)

I'm getting good download speeds, even at busy times. It even drops back to GPRS when neccesary!

Thanx CoreyPlover and peterh_oz for your help. I'm a happy little puppy.