N900 UK Networks - Page 37 - maemo.org

jaark | # 361 | 2009-11-11, 16:13 | Report

Originally Posted by jjx View Post

Still, none of this explains why 3 sometimes shows great reception but little or no data throughput!

Unfortunately, the signal indicators on phones are generally pretty deceptive. They only show signal strength and do not give an indication of snr (signal to noise ratio). It is perfectly possible to have a strong, but unusable signal and your phone won't tell you.

Fargus | # 362 | 2009-11-11, 16:15 | Report

Originally Posted by jaark View Post

Unfortunately, the signal indicators on phones are generally pretty deceptive. They only show signal strength and do not give an indication of snr (signal to noise ratio). It is perfectly possible to have a strong, but unusable signal and your phone won't tell you.

Now the question is, can we determine the level of noise and useable signal? If so then maybe this is a widget waiting to happen? Suppose the other potential measure is that of throughput or number of cell requests issued by the phone - is this information available to the software stack?

Might be nice to be able to do this for each operator visibile - be interesting to see if another provider gives a better signal in locations relevant to the individual too.

Last edited by Fargus; 2009-11-11 at 16:16. Reason: Additional

JBax | # 363 | 2009-11-11, 16:18 | Report

evad please check your PMs

Thanks

JBax | # 364 | 2009-11-11, 16:28 | Report

Originally Posted by eiffel View Post

The best news is that the Vodafone PAYG price has gone back down to £393 (having started there, then changed to £449 for a few weeks). Add £4 shipping.

http://www.nokiaretail.co.uk/
(Click on "View more tariffs")

Bad news, just got off the phone to MPD about this deal.

MPD have stopped sim free versions and the PAYG version is locked to vodaphone as it comes with the PAYG sim to use. Whether or not that means it is branded aswell wasnt made clear but its defiantly locked

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eiffel | # 365 | 2009-11-11, 16:33 | Report

Originally Posted by JBax View Post

Is Vodafone unbranded and no own software?

Everyone who asked the MPD sales staff was told that the Vodafone PAYG deal is an unlocked N900 plus a Vodafone PAYG SIM Card, but it wouldn't hurt to ask again when you pay over your money.

(Edit: it seems what I said above is obsoleted by JBax's post to the contrary.)

Last edited by eiffel; 2009-11-11 at 16:38.

rash.m2k | # 366 | 2009-11-11, 16:36 | Report

Originally Posted by jaark View Post

Unfortunately, the signal indicators on phones are generally pretty deceptive. They only show signal strength and do not give an indication of snr (signal to noise ratio). It is perfectly possible to have a strong, but unusable signal and your phone won't tell you.

I can't get my head around this.

SNR and signal strength both depend on the amount of errors within the bit stream. Therefore a low strength signal will be easily corrupted and the phone will show this. The phone obviously tries to reduce the speed at which its operating (e.g. 3G to 2G, Edge to 2G etc.) in an attempt to decrease the amount of uncorrectable errors.

On the other hand if you have a strong signal and high SNR, then you will still get corrupted bits - and so the phone will still try and reduce the speed at which it is communicating with the tower.

Ultimately - SNR and signal strength go hand in hand. The way I see it a phone cannot have strong but unusable signal? Especially with 3G/UMTS signals where it must decode the bitstream with it's own key (3G uses DSSS - hence constant power adjustment reduces battery life).

Feel free to enlighten me.

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JBax | # 367 | 2009-11-11, 16:41 | Report

Well, this isnt good for those who have yet to place orders. There are others like Handtec offering the phone at around £440-50 mark but they have no clue when they are getting the batch after emailing them 3 days ago. So the logical guess is the 30/11 like most more expensive others

evad | # 368 | 2009-11-11, 16:48 | Report

Originally Posted by JBax View Post

Well, this isnt good for those who have yet to place orders. There are others like Handtec offering the phone at around £440-50 mark but they have no clue when they are getting the batch after emailing them 3 days ago. So the logical guess is the 30/11 like most more expensive others

MPD has 7 days returns policy, so you might trying to place the order for payg handset, when it comes and turnes out it's locked, then return it. Done.

However once you've been told they ARE actually locked (which is strange, tbh), then I'm not sure if return would work...

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JBax | # 369 | 2009-11-11, 16:54 | Report

Originally Posted by evad View Post

MPD has 7 days returns policy, so you might trying to place the order for payg handset, when it comes and turnes out it's locked, then return it. Done.

However once you've been told they ARE actually locked (which is strange, tbh), then I'm not sure if return would work...

I'm not going to risk it to be honest. Tried the online chat route aswell and the guy confirmed it will be locked. Although he got annoyed when I asked if this was a physical lock to the network or just part of the contract Vodafone has told MPD to sell it as. He just said the word locked.

I agree it looks weird as Nokia said the handsets would be unlocked from the start but dont want to risk it when I dont have enough certainty.

UPDATE: MPD Chat member said the sim free version should be back in a few days (guessing after the 500 or so pre orders they have for it have been dealt with). Dont know whether to believe him though with 2 MPD sources in direct conflict.

Hope this helps anyone in the same situation as me

Last edited by JBax; 2009-11-11 at 17:03.

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jaark | # 370 | 2009-11-11, 17:04 | Report

Originally Posted by Fargus View Post

Now the question is, can we determine the level of noise and useable signal? If so then maybe this is a widget waiting to happen?

Obviously it depends on what data the radio provides to user software - I have no idea if it does pass this sort of thing.

Originally Posted by rash.m2k View Post

I can't get my head around this.

.
.
.

Feel free to enlighten me.

I was pretty much paraphrasing my understanding of an article I read a couple of years ago - I've had a quick look, but can't find it right now. I'm no radio comms expert but I do know that signal field strength and the snr are two different and independent things and that the snr can fluctuate but the field strength stays fairly constant with a static receiver and transmitter.

jjx was aking why he had a strong signal indicator (which only shows signal field strength) but very poor data throughput - a situation that can easily be explained by noise affecting transmission.