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Posts: 20 | Thanked: 3 times | Joined on Sep 2007
#21
I had the same problems for a long time - all solved now mostly.

I troubleshooted it for a long time with no help from WIND - I am on unlimited voice and data plan.

My progressive and compunded conclusions were as follows:

1)
On the network that has both, the provider often uplinks to 3.5 on download requests - in some cases (mine) always - which results in no stable internet over 3G (because of the ping pong between 3 - 3.5).

2)
I thought my phone was faulty, got a new SIM etc.- with not much of an improvement. Some improvement was noticed when new SIM cards were used and set-up with no PIN. So I am not using PIN at the moment as this seemed to help reliably. So not a SIM card issue - but certainly a PIN implications (possibly with timing, delays, handshake negotiation etc).

3)
Signal strenght issues (too low of a signal strength resulted in frequent failures when switching to 3.5 G and thus disconnects).
Too low a signal in 3.5 mode resulted in icon showing 3.5 while negotiation continued (with no data sent) untilit went back to 3G mode and then back to 3.5 etc. Forever.

4)
Possible energy management issue with n900 itself - I suspect that if everrything was on (bluetooth, wifi, gps, led, sound, etc.) ans 3.5G mode required great deal more juice - the N900 was not responsive enough in providing it. This likely contributed to the frequent disconnects. Turning off what I have not used, and running with screen-off resolves most of the problems for me.

5)
Rinning Titan's Kernel with overclock helped a lot as well. Due to the phone being more responsive (things take less time) as well as
realizing that I have power issues while trying to run at high frequences. This helped me realize the power management contention issues that came into play even more when 3.5G mode was called on (I have read that 3.5 modem can use up to 2A at the time! ).
This was more pronounced when I understood that the phone would up-shift CPU frequency when I tried to download data - resulting in both modem and the CPU asking for more juice at once. Now I have 2 energy/performance specific modes that I can alternate between as needed.

6) There are problemes with phonenet that I discovered. This is likely due to set-up and tear-down issues with network establishement using the defined APN that is used for the Internet specific activity. This resulted in freez-ups and crashes in rfconnect.ko module (as far as I recall the names now).

My testing suggested that whenever I use the ppp connection
instead of the default "Cellular Data" my connections would be much more stable and predictable.


7) I have added a new packet connection as a redundant APN
with the same configuration data - just a diferrent name.
I made both of them not start automatically anymore.
This allows me to use my own APN whenever I use the Web from the phone itself, while the modem and phone can use the "Cellular Data" default APN. You may think that I am insane - but this helped me the most in using the 3.5 data on the go.

My conclusion is that default "Celluar Data" APN configuration is used to switch to 3.5G mode (I could call it data mode where possibly PIN, but certainly user/password/IMEI information is checked/verified on handshake). This happens automatically and on some pre-determined timing. The phone will connect every so often to the tower to check/confirm signal strength, pick-up SMSes, etc. This takes precwedence over any data connectivity - and it seems synchronous activity (no multiplexing capabilities when it happens) that is interrupting what else was happening. During this activity my data connectivity would suffer (frequent disconnects and delays) the most. By forcing my own APN (same config - diferrent name) before connecting to the web - the phone signaling/management activities no longer impact my data connectivity as much - as if my custom 3.5 G APN connection is not teared-down - when signaling on 3G occurs..

8) I had a lot of problems when I had both 2/3G selected as well - this is because phone keeps getting bombarded with signaling data from all of the networks. The stronger 2G signal would often kill my 3G (and even more often my 3.5 G connections). Sometime this would be resulting in data connectivity loss - which had to be
re-acquired (after all timeouts and handshaking had a chance to complete) resulting in terrible end-user experience. I never had that problem before with 2/2.5 G vendors/phones.
Sometimes I would lose my "Home" network and the phone app would crash on occasions as well. THis was happening even if the phone was stationary and manualy tied to my "Wind Home" zone. The phone would switch to "Wind Away" and rarely back (or crash completeley). Situation improved when I disabled 2G completely and made my network provider "automatic" but 3G only.

9) Finally I have asked Wind to supress roaming on my account completely - no switching my phone to other vendors at all.
This helped a lot too. I can always enable it back when necessary for travel, etc.


My final conclusion is that 3G networks (i.e. Wind) are 3G in name mostly. My phone only works in 1 room of my house - the signal can't penetrate 2-brick wall.

The signal is shaky, their equipment suffers form lots of fluctuations and failures. It seems to be load affected, weather affected etc.

They have ISP issues - with DNS servers, NAT gateways etc.

They filter and throttle traffic - which results in users perceiving "frequent disconnections" - as I was.

They purposely slow us down, introduce interruptions in larger transfers - sending bougus packets to the phones/modems - which results in various recovery specific delays and/or crashes.

They periodically diconnect users from their APNs forcing reconnections (specially in streaming and large downloads) - with no reagard for what one was trying to do in the meanwhile, etc. And they take customers for granted.
The network providers are mostly at fault here!


All of the above results with us being unhappy with the n900.

In my opinion, N900 has some problems with energy management (including charging/BME defaults/behaviour) and predatory on-demand governor behaviour (that can be managed by more knowledgable users only) and with the APN stack conflicting with
regular phone behaviour on poor networks (this is not as profound when using phonet with PPP).

I could use ppp instead of APN on the phone itself (much more resilaiant and reliable), but I see no need to do that anymore, as my data connections are much more satisfying.

Nowadays the one room my phone works in, has a wifi router connected to it and a phone number forwarded to my home phone - when I am in the house.


In a nutshel - a lot of usabilty issues are in-fact sophisticated and compunded problems.

For instance default USB driver in windows (any version) needs to be updated with a special hotfix from Microsoft to avoid frequent disconnects on larger downloads - yet thouse using n900 to tether are likely to blame Nokia for it.

N900 is a best phone money can buy - but it needs a passionate owner who is technically savy to appreciate that.

Nokia is a visionary with its 770/800/900 revolution - but those that do not know linux, or telco implications are bound to blame the phone itself and a company that made it.


netC