3G in U.S. vs Europe/Asia [Archive] - maemo.org

View Full Version : 3G in U.S. vs Europe/Asia

kenny

2009-09-12, 15:26

In post #98 of this thread
http://talk.maemo.org/showthread.php?t=31284&page=10
I try to address a comment made by Christexaport as to the inter-workings of the 2100mhz band.
Now it's got me to thinking;

1) Can a knowledgeable person inform us of the differences between UMTS Band I and UMTS Band IV?
2) T-Mobile-U.S. does use both the 1700 and the 2100mhz bands for up and down 3G transmissions, correct?
3) Is the 2100mhz capability of the N900 compatible with both the U.S and the European/Asian protocols?

I would assume that the answer to #3 is "yes," but I would like a technical explanation.

Mara

2009-09-12, 15:45

It is not as simple... Please take a look at this (http://www.phonescoop.com/articles/article.php?a=99&p=1493).

EDIT: To add a bit to this... The downlink (tower to mobile) bands are compatible between North America and Europe, but the uplink (mobile to tower) are different. The T-Mobile USA uses the 1700MHz band for this, while AT&T uses 1900MHz band as far as I know. In Europe the uplink is slightly below 2000MHz. (And then there is the European 900MHz band that is used in many rural areas.)

christexaport

2009-09-12, 18:55

Here's the skinny. TMobileUSA uses both frequencies, and you can't get by with just one, because one is for up and the other down. We in the US call 1700/2100 TMobile 3G because they are the first to use this frequency, and currently the only ones with a network deployed afaik. (This is why I confuse some by calling the N900 a TMobile device. In the Americas, its the only carrier that can provide consistent 3G.

at&t uses 850/1900, and uses each frequency on the up and down. Some markets are purely 850, some are 1900, and some have both, so you can get by with one of either bands, but connections are hit and miss. The N900 supports none of its 3G frequencies anyway, just EDGE data, so its a nonconversation.

I'm only stating what I've "learned" from investigating this myself over the years, but the 1700/2100 for AWS won't be compatible with the 2100used in Asia. The reason why is this:

UMTS IV is what Americans call AWS or TMobile 3G. It uses 1710 - 1755 MHz on upload channels 1312 - 1513, plus 1662, 1687, 1712, 1737, 1762, 1787, 1812, 1837, and 1862,

...and 2110 - 2155 MHz on download channels 1537 - 1738, plus 1887, 1912, 1937, 1962, 1987, 2012, 2037, 2062, and 2087.

Now UMTS I is what the world considers IMT 3G . It uses 1920 - 1980 MHz on upload channels 9612 - 9888,

...and 2110 - 2170 MHz on download channels 10562 - 10838.

So unless the WCDMA radio in the N900 can handle 1710 - 1755 plus 1920 - 1980 on upload channels 1312 - 1513, plus 1662, 1687, 1712, 1737, 1762, 1787, 1812, 1837, 1862, and 9612 - 9888,

...AND 2110 - 2170 MHz on download channels 1537 - 1738, plus 1887, 1912, 1937, 1962, 1987, 2012, 2037, 2062, and 2087 PLUS 10562 - 10838,

...it won't cover all of the markets everyone assumes. This is why I still think Nokia must expect a subsidy from TMobileUSA somewhere down the road, or are using this as a measure to see how fast it will sell in the US on TMobileUSA with no subsidy.

christexaport

2009-09-12, 19:00

So the 900 is just for European, Australian, New Zealand, and Asian 900 MHz markets and TMobileUSA, based on frequency. Or its not AWS at all, and just a weird combination of frequencies. Or maybe Nokia has expanded the width of the radios to adress the problems of compatibility between UMTS I and IV.

christexaport

2009-09-12, 19:11

So we can assume the 900 MHz is GSM Band VIII, for Europe, Asia, Australia, New Zealand.

We can also assume the 1700 MHz is for Canada and the USA.

The question no one has asked Nokia is whether the 2100 MHz frequency is Band I AND IV compliant, or only Band I, or only Band IV. Any Nokians have the inside scoop?

texaslabrat

2009-09-12, 19:11

So the N900 is just for European, Australian, New Zealand, and Asian 900 MHz markets and TMobileUSA, based on frequency. Or its not AWS at all, and just a weird combination of frequencies. Or maybe Nokia has expanded the width of the radios to adress the problems of compatibility between UMTS I and IV.

There is no reason why the radios should not work in each market. They are tunable via software, and as long as the frequency is in the "band" of frequencies (ie the "2100" band, the "850" band, etc) it will work just fine since the antenna is of proper geometry to properly receive signals in that slice of spectrum.

The frequencies chosen by Nokia were to "harmonize" as many markets as possible with a single device configuration in order to reduce launch costs. If T-mobile picks it up on subsidy, so much the better. If you'll notice, the N900 being offered on the U.K. site is 900/1700/2100 as well. Does it make more sense that there is a single device capable of working across Europe/Asia as well as North America/AWS, or do you really think that they made two separate versions with the EXACT same 3g bands built-in...which would only work in one market or the other (with the european version having a useless 1700 radio). As I've pointed out in other threads...Occam's Razor rules the day. 2100 is 2100 is 2100 as far as the hardware is concerned.

ysss

2009-09-12, 19:15

Most of the world's 3G operators use 2100mhz UMTS:

http://en.wikipedia.org/wiki/List_of_UMTS_networks

I think a brief glimpse of this list should make it crystal clear of what kind of 2100mhz Nokia would and should support on any of their 3G handset.

christexaport

2009-09-12, 19:23

I agree, Texrat, but only if the WCDMA radio supports both bands and applicable channels.

"...AND 2110 - 2170 MHz on download channels 1537 - 1738, plus 1887, 1912, 1937, 1962, 1987, 2012, 2037, 2062, and 2087 PLUS 10562 - 10838, "

I'd always been told that the TMobile 2100 wasn't compatible with the "Asian" 2100, but I'm not for sure.

I don't think they have made a separate device for markets outside of the US, but unless the 2100 MHz radio supports Bands I and IV, which no one has confirmed so far, I expect they would. Otherwise Asia is also shut out.

I'm also shocked that they have left at&t and a majority of the 3G Americas markets untapped. It doesn't look like Nokia intended any Americans to have the N900, but the AWS inclusion says at least a small, albeit good, part of the US was important.

As far as offering the N900 everywhere in its current configuration, I and many others will buy it with or without 3G connectivity, and maybe Nokia knows that. The original Maemo tablets had no 3G either, but they sold ok. As long as it has wifi, it has a place everywhere. I don't even plan to use a SIM when mine arrives.

christexaport

2009-09-12, 19:25

Most european and asian 3G operators use 2100mhz UMTS:

http://en.wikipedia.org/wiki/List_of_UMTS_networks

But that's Band I, not Band IV. Can one radio cover both bands? It should, as Texrat says, but can that be confirmed? Because some TMobile hardware won't work in Asia, I've heard.

SD69

2009-09-12, 19:35

There is no reason why the radios should not work in each market. They are tunable via software, and as long as the frequency is in the "band" of frequencies (ie the "2100" band, the "850" band, etc) it will work just fine since the antenna is of proper geometry to properly receive signals in that slice of spectrum.

Baseband UMTS chips tunable via software? That's news to me. Do you have a link?

texaslabrat

2009-09-12, 19:48

Baseband UMTS chips tunable via software? That's news to me. Do you have a link?

how do you think cell tower handoff happens? Adjacent towers use different freqs.

SD69

2009-09-12, 19:52

how do you think cell tower handoff happens? Adjacent towers use different freqs.What does that have to do with making baseband UMTS chips tunable via software?

kenny

2009-09-12, 20:02

So the N900 is just for European, Australian, New Zealand, and Asian 900 MHz markets...........

No.
2100 for Europe and Asia.
900 mainly for Oz &NZ.
(Please see the thread that I referred to in post #1 as I have already tried to answer you concerning the frequencies and I have linked to the Wikipedia page.)
.
.
It looks like my original assumption is correct. A present day 2100mhz radio will send and/or receive all of the various 2100 MHz bandwidth subdivisions (i.e., both Band I and Band IV.).

IOW, the one (and only one) N900 will work with T-Mobile's 3G network in the U.S. and most everybody's 3G network in Europe and Asia.
Thank you all for clarifying and reaffirming this.

texaslabrat

2009-09-12, 20:02

What does that have to do with making baseband UMTS chips tunable via software?

if one tower uses x freq, and another tower uses y freq..the radio must tune from one freq to the other. This action is iniated by software. There isn't a tiny knob being turned by nanobots. Cellular radios have a range of freqs they are usable on which is determined by physical attributes (antenna cinfiguration, amp circuit, etc). Once again, if the radio is physically capable of tuning a given range of freqs (2100 range,850range, etc) then tuning to one channel versus another is a matter of a software command...just like modern fm stereos that have soft buttons for tuning rather than physical knobs.

texaslabrat

2009-09-12, 20:22

But that's Band I, not Band IV. Can one radio cover both bands? It should, as Texrat says, but can that be confirmed? Because some TMobile hardware won't work in Asia, I've heard.

if the phone doesn't know to attempt a connection on certain channels, it won't try. It's a software issue, not a radio issue.

SD69

2009-09-12, 20:23

if one tower uses x freq, and another tower uses y freq..the radio must tune from one freq to the other. This action is iniated by software. There isn't a tiny knob being turned by nanobots. Cellular radios have a range of freqs they are usable on which is determined by physical attributes (antenna cinfiguration, amp circuit, etc). Once again, if the radio is physically capable of tuning a given range of freqs (2100 range,850range, etc) then tuning to one channel versus another is a matter of a software command...just like modern fm stereos that have soft buttons for tuning rather than physical knobs.Baseband UMTS radio chips are much more complicated than FM chips and are not tunable by software across a continuum of frequencies. Currently, they can only operate on the pre-defined channels in a limited number of pre-defined bands. I have an engineering degree. I'm not guessing here.

texaslabrat

2009-09-12, 20:42

Baseband UMTS radio chips are much more complicated than FM chips and are not tunable by software across a continuum of frequencies. Currently, they can only operate on the pre-defined channels in a limited number of pre-defined bands. I have an engineering degree. I'm not guessing here.

as do I. Difference is, I'm right on this issue. And yes, they are tunable across a set of frequencies for which they are designed. The firmware controlling the radio may only have certain 'presets' available for the telephony stack to choose, but that's not a physical limitation. Once again...does it even make sense from a layman's point of view that the european n900 would have a 1700 radio if the 2100 radio was unusable in the states on AWS bands? Seriously...think about that for a second.

ysss

2009-09-12, 20:50

texaslabrat

2009-09-12, 20:53

Hm.. just a quick question. When Nokia release a particular cellphone model with different radio support for different regions in the past, do they mark them differently? (Perhaps with a different model number, or suffix, or something that can be discerned on the spec page)

Or do they just make use of their distribution channels to deliver the correct spec to the correct region, thus making cross broder sales a risky endeavour for the buyer?

Well the N95 was specially released for the U.S. market with the "NAM" moniker (and more specifically with the "n95-3" label)...I don't know if they had a special serial number range though I'm sure they did.

dunno if that helps

ysss

2009-09-12, 20:56

texaslabrat

2009-09-12, 21:02

@texaslabrat: perhaps I should invert the question..

If the N900 (for some reason) are in fact outfitted with different radio for different region (ie: nam vs rest of the world), wouldn't they carry different model number\mark of distinction?

I would imagine so...yes. Plus, if the "2100 issue" was indeed real...you would find a lack of 1700 radio in the european models so that Nokia could squeeze out a few more dollars per unit since they would have to have a differentiated manufacturing process anyway to fit the "specific" 2100 radios. Hence, you put all those things together and you can reasonably conclude that there is only a single physical model being launched from the RF point of view.

kenny

2009-09-12, 21:11

SD69

2009-09-12, 21:21

as do I. Difference is, I'm right on this issue. And yes, they are tunable across a set of frequencies for which they are designed. The firmware controlling the radio may only have certain 'presets' available for the telephony stack to choose, but that's not a physical limitation. A typical UMTS chip can only tune to a limited number of standardized bands, i.e., Bands I, IV and X. The firmware tells the chip which one of those 3 standardized bands to use.

The word "presets" suggests that the chip can tune to 10 UMTS bands, and the firmware fails to take full advantage of all 10 bands and can only instruct the chip to tune to one of 3 out of the 10 bands. which is not what happens.

texaslabrat

2009-09-12, 21:29

Wow, it's an Engineering Faceoff.....
This is physical science here folks, it's black and white, it either is or it ain't.
Ya know, I've spent untold hours here on this forum over the past few years, and I've slogged my way through countless posts, all in an effort to find out....... THE TRUTH.
And my point is.........uh, I dunno.

Heh, I think my "opponent's" confusion stems from the channels that the radios are allowed/programmed to access versus what is physically accessible over the air due to the radio design. Yes, they are restricted to certain channels/frequencies within each market. But as you change markets, you get a new set of channels to play with. As long as the firmware/software is aware of the new channels, the radio is fully capable of tuning to them from a physical standpoint. And if your telephony stack is smart enough to figure out what market it is in and cross-reference the channels allowable to transmit there, then you're golden ;) It's a similar case with WiFi...in the U.S. only channels 1-11 are allowed (B/G), though nearly all wifi radios are capable of accessing more channels (which are legal in other countries). Usually the stock firmware keeps you from trying to actually *use* those channels if you bought your AP in the U.S., but that's easily fixed with a firmware swap. It doesn't make sense for manufacturers to create 2 sets of radios for different markets when they can control which channels are used through software.

@ chris: Another possiblilty with those t-mobile devices that had trouble in Asian markets is that perhaps the 2100 radio was receive-only (to save money) since they were only meant for the U.S. market rather than being "world phones". Without knowing what models you are talking about, I can only speculate.

SD69

2009-09-12, 21:34

texaslabrat

2009-09-12, 21:35

A typical UMTS chip can only tune to a limited number of standardized bands, i.e., Bands I, IV and X. The firmware tells the chip which one of those 3 standardized bands to use.

The word "presets" suggests that the chip can tune to 10 UMTS bands, and the firmware fails to take full advantage of all 10 bands and can only instruct the chip to tune to one of 3 out of the 10 bands. which is not what happens.

Well, considering that the N900 *WILL* work in both markets...I submit that you are wrong ;)

And no, my use of "presets" means the channels within a given band that the radio is allowed to tune to. The "band" distinction is done in firmware, not hardware (insofar that there is a certain set of channels that are currently allowed). The radios only know frequencies..they could care less what "band" it belongs to. You send a signal to tune to xyz megahertz...and it will happily comply if it is physically capable of doing so. Carving out discreet logical channels out of the continuum of spectrum is the job for higher up the stack. "Band" distinctions are accounting labels we give for our regulatory forces to keep track of what frequencies are used for what purposes..they have no relevance in at the RF level which the radios operate.

texaslabrat

2009-09-12, 21:40

I'm not sure what labrat is saying

Yeah, I think that's the disconnect here....

SD69

2009-09-12, 21:51

Well, considering that the N900 *WILL* work in both markets...I submit that you are wrong ;)Huh? The N900 probably has a UMTS radio chip that supports only Bands I, IV and X. The N900 works in Europe because Europe uses Band I and works on T-Mobile US because T-Mobile US uses Band IV. I am saying it is not possible for any software to make the radio chip in the N900 work in Band II.

texaslabrat

2009-09-12, 22:07

Huh? The N900 probably has a UMTS radio chip that supports only Bands I, IV and X. The N900 works in Europe because Europe uses Band I and works on T-Mobile US because T-Mobile US uses Band IV. I am saying it is not possible for any software to make the radio chip in the N900 work in Band II.

"probably"? I thought you weren't guessing here ;) You had also previously asserted (unless I am associating a comment to the wrong person) that the european "2100" is different and thus incompatible with "AWS 2100" (and by extension would require a separate radio). Apologies if that is incorrect.

In any case, it will work in both markets because the radios are software-tunable to all applicable frequencies included in the bands required to operate in the markets for which it is destined. The "bands" are defined at the firmware/software level, not the radio level. Only frequency ranges are defined on the radios as a function of the antenna design and the op-amp and other circuit considerations to match the ocillator-related-stuff with the frequencies. Now, those channels (ie discreet frequency points for transmit and receive on the appropriate radios) could very well be hard-coded on a chip (but are more often firmware-related if not out-and-out completely in software depending on the overall system architecture)..but that chip is *not* the radio. I think that's the piece of the puzzle you are missing. With a different set of commands to choose different frequecies..the same *radio* can tune to any frequency within its design limit irrespective of what "band" it belongs to.

What you are suggesting is akin to saying that since I have my Austin radio stations programmed in my stereo...that somehow the hardware is locked into only working in Austin since none of those presets will match up if I go to Dallas. If I restrict myself to ONLY using those presets...yes..but that's not a limitation of the underlying radio hardware...it is a software issue.

As for your "1900"/Band II assertion..I agree. And I never claimed that a radio that is designed for 900 could tune to a 1900 frequency. Nor did I claim that a 1700 radio could tune to a 1900 frequency. Nor did I claim that a 2100 radio could tune to a 1900 frequency. Since none of the radios have the breadth of frequency response to successfully communicate on 1900, of course no software could overcome that physical limitation. But that's not what we're talking about here re: the overlapping 2100 bands between I and IV, now is it? Kudos for the strawman argument though..well played, sir.

SD69

2009-09-12, 22:18

Yeah, I think that's the disconnect here....I was just trying to figure out what you are saying and trying to give the benefit of a doubt.

And no, my use of "presets" means the channels within a given band that the radio is allowed to tune to. The "band" distinction is done in firmware, not hardware (insofar that there is a certain set of channels that are currently allowed). The radios only know frequencies..they could care less what "band" it belongs to. You send a signal to tune to xyz megahertz...and it will happily comply if it is physically capable of doing so. Carving out discreet logical channels out of the continuum of spectrum is the job for higher up the stack. OK, now I know you are blowing smoke. The FCC won't let the frequency on which a cellular radio chip transmits be set in a software stack because then someone could alter the device to transmit on an unpermitted frequency.

texaslabrat

2009-09-12, 22:25

I was just trying to figure out what you are saying and trying to give the benefit of a doubt.

OK, now I know you are blowing smoke. The FCC won't let the frequency on which a cellular radio chip transmits be set in a software stack because then someone could alter the device to transmit on an unpermitted frequency.

Nope it happens...that's why the device is tested as a whole with the market-specific firmware/software. In fact, people often did that very thing with dual and tri-band phones to change them from U.S. market phones to European market, or vice versa (the 850 is close enough to 900, and 1800 is close enough to 1900) via a firmware flash. That was GSM, but same concept. And I again point to my wifi example of this very concept as well. I'm pretty sure the FCC tested/approved those too ;)

Do you really think they are cranking out hard-coded controller chips with every specific band combination laid out in transistors? LOL. Nope..they make one kind and program it.

SD69

2009-09-12, 22:36

"probably"? I thought you weren't guessing here ;) You had also previously asserted (unless I am associating a comment to the wrong person) that the european "2100" is different and thus incompatible with "AWS 2100" (and by extension would require a separate radio). Apologies if that is incorrect.Of course, I don't know what UMTS chip is in the N900. But I have plenty of prior experience with how with cellular rf chips work and what you describe is inconsistent with that.

Look at the link in post #25 - the two bands are different.

In any case, it will work in both markets because the radios are software-tunable to all applicable frequencies included in the bands required to operate in the markets for which it is destined. The "bands" are defined at the firmware/software level, not the radio level. Only frequency ranges are defined on the radios as a function of the antenna design and the op-amp and other circuit considerations to match the ocillator-related-stuff with the frequencies. Now, those channels (ie discreet frequency points for transmit and receive on the appropriate radios) could very well be hard-coded on a chip (but are more often firmware-related if not out-and-out completely in software depending on the overall system architecture)..but that chip is *not* the radio. I think that's the piece of the puzzle you are missing. With a different set of commands to choose different frequecies..the same *radio* can tune to any frequency within its design limit irrespective of what "band" it belongs to.

What you are suggesting is akin to saying that since I have my Austin radio stations programmed in my stereo...that somehow the hardware is locked into only working in Austin since none of those presets will match up if I go to Dallas. If I restrict myself to ONLY using those presets...yes..but that's not a limitation of the underlying radio hardware...it is a software issue.
Do you know firsthand that what you describe has been done in a UMTS cellular device? Or have you seen what you describe in FM radio and extrapolating that it's done the same way in UMTS cellular?

texaslabrat

2009-09-12, 22:56

Do you know firsthand that what you describe has been done in a UMTS cellular device? Or have you seen what you describe in FM radio and extrapolating that it's done the same way in UMTS cellular?

I have first-hand knowlege of how this works in GSM, FM, and various "other" communication technologies which I won't go into here. I admit I have not personally been on a UMTS design team. However, a radio is is a radio is a radio. At then end of the day, it is photons exciting a conductor, or an excited conductor emitting photons. RF is a continuous spectrum...it would be *exceedingly* difficult to design a radio that only responded to discrete frequencies. That's why radios for these applications are software tunable...and it is the firmware/software stack that dictates what channels will be used. Seriously...this is common-sense kind of stuff for someone in the industry.

Now we go into the semiconductor industry. Fabs make money based on economy of scale. Hence, there is a HUGE incentive to make hardware for a given application standardized so that they can make a LOT of the same kind....which leads to the programability of said chips. They make ONE chip...and program it with the data it needs to access the appropriate channels. It then, in turn, requests the corresponding frequencies from the radio. It's really not that complicated. The "complicated" stuff happens further up the stack with the signal encoding/decoding according to the various protocols in play.

Truly, you really seem to be confusing the "radio" with the "controller". They may be present on the same silicon, but they are separate entities if you view it from the block-level perspective. With the push to consolidation (SoC, mutli-band radios, etc), it would be economic suicide if they tried to hard-code this stuff and had to have different fab runs to serve different markets. It just doesn't work that way. Now, could they use FPGA's and make the allowable frequencies/channels pseudo-hard-coded? Sure they could. But that's still a level up the stack from the actual radio and thus effectively a software issue since the configuration is still independent of the actual radio. For those FPGA's that can be re-flashed...you could (with appropriate gear) re-flash them to new channels. But that's a lot of work (not to mention fpga's are more expensive than simply having a programmable controller controlled through traditional flash-based firmware) hence most of this stuff is done in firmware.

Anyway, if you would like to continue spitting into the wind...be my guest. The facts speak for themselves.

kenny

2009-09-12, 23:16

WOO- HOO !!!
d_mn, this is good stuff !!

YoDude

2009-09-12, 23:27

Umm... I'm not what you would call one of them bona fide internet inguneers like you fellas are but I do get to play with some neat stuff. I even get paid for it... now and then. :)

I'm pretty sure variations of what texaslabrat describes have been used in cell radios for a couple of years now.

http://files.myopera.com/yodude/blog/radioresources.png

jandmdickerson

2009-09-12, 23:47

In other words, if I don't get a 3g signal and speed when I first use my N900, here in California on TMobile, then I will ship it back for a full refund.;)

kenny

2009-09-13, 00:10

You had also previously asserted (unless I am associating a comment to the wrong person) that the european "2100" is different and thus incompatible with "AWS 2100". Apologies if that is incorrect.

Uh, that might have been me as this was what I wanted to confirm was wrong in post #1, thanks to Christexaport.
.
I had heard that 2100 incompatible story before.....it seems to have been quite a widespread theory these past few years.

kenny

2009-09-13, 00:16

@ chris: Another possiblilty with those t-mobile devices that had trouble in Asian markets is that perhaps the 2100 radio was receive-only (to save money) since they were only meant for the U.S. market rather than being "world phones". Without knowing what models you are talking about, I can only speculate.

BINGO!
Without bothering to check, I'd say that sounds very plausible.
.
Issues like this probably helped to contribute to the "non-compatible 2100" stories.

SD69

2009-09-13, 02:11

I have first-hand knowlege of how this works in GSM, FM, and various "other" communication technologies which I won't go into here. I admit I have not personally been on a UMTS design team. I've worked with WiMax chip designers and dealt with the UMTS specs for years, but that was awhile ago and I have never been an expert. I don't know the current state of the art - but I do know that UMTS chips tunable by software (if it has even happened) would be a significant development. As I suspected, you are extrapolating rather than relying on knowledge.

However, a radio is is a radio is a radio. At then end of the day, it is photons exciting a conductor, or an excited conductor emitting photons. RF is a continuous spectrum...it would be *exceedingly* difficult to design a radio that only responded to discrete frequencies. Hmmm..., you started out in post #6 by saying the radios are tunable by software. in post #14, you said "if" the radio is physically capable of tuning a given range of freqs(2100 range,850range, etc) then tuning to one channel versus another is a matter of a software command." In post #29, you said "Nor did I claim that a 1700 radio could tune to a 1900 frequency." Now you say this - seems inconsistent.

That's why radios for these applications are software tunable...and it is the firmware/software stack that dictates what channels will be used. Seriously...this is common-sense kind of stuff for someone in the industry.A telephony stack may switch the device to a different channel, but that's not what you said. You said that the software tells the chip to tune to "frequency XYZ", and it does not tell the radio chip to tune to frequency XYZ. The only channels available are determined by the hardware, and the software cannot change the frequency or bandwidth of the channels.

Now we go into the semiconductor industry. Fabs make money based on economy of scale. Hence, there is a HUGE incentive to make hardware for a given application standardized so that they can make a LOT of the same kind....which leads to the programability of said chips. They make ONE chip...and program it with the data it needs to access the appropriate channels. It then, in turn, requests the corresponding frequencies from the radio. If you mean that the semiconductor company programs the UMTS chip at the time of manufacture, then I don't disagree. The point is that when Nokia uses a UMTS chip in a device, it cannot, through software, change the chip's frequencies at will to any frequency it wants.

Truly, you really seem to be confusing the "radio" with the "controller". They may be present on the same silicon, but they are separate entities if you view it from the block-level perspective. With the push to consolidation (SoC, mutli-band radios, etc), it would be economic suicide if they tried to hard-code this stuff and had to have different fab runs to serve different markets. It just doesn't work that way. Now, could they use FPGA's and make the allowable frequencies/channels pseudo-hard-coded? Sure they could. But that's still a level up the stack from the actual radio and thus effectively a software issue since the configuration is still independent of the actual radio. For those FPGA's that can be re-flashed...you could (with appropriate gear) re-flash them to new channels. But that's a lot of work (not to mention fpga's are more expensive than simply having a programmable controller controlled through traditional flash-based firmware) hence most of this stuff is done in firmware.I don't think I ever said "radios" - I said "chips". Why are you talking about the way the chips are manufactured? We are debating whether there are UMTS chips which are tunable by software.

Anyway, if you would like to continue spitting into the wind...be my guest. The facts speak for themselves.
Please, please, give some facts. You asserted that the frequencies are tunable by software and I started out asking for a link and you still haven't given one. ;) You claimed Bands I and IV are not different because they both include 2100 MHz and I posted the wikipedia link that says otherwise. Facts are most welcome.

p.s. I'm not trying to give you a hard time personally. The problem is that when you say something like the radio frequencies are "tunable by software", there will be many people who get the misimpression that Nokia could change the frequency incompatibilities of the N900 through software.

texaslabrat

2009-09-13, 03:20

SD:

I've repeatedly said OVER AND OVER that the tunability is restricted within the frequency ranges that the radio is physically designed for. Things like the antenna and the oscillator circuits are designed for certain frequency ranges. Just because you choose to ignore, OVER AND OVER, that bit of information doesn't make you right. Seriously. Get over it.

And cripes...again regarding the frequency vs. channel thing. One more time...typing really slow....a channel is simply a LABEL for a given frequency (it is actually mathematically derived FROM the frequency, in fact, via a formula in the standard) . It is a swath of bandwidth with a centerpoint frequency. If you tell your radio to tune to "channel 1096", it will look at you funny. Instead, you tell it to tune to 2135.6 Mhz (or whatever..pulling numbers out of the air here).

Seriously, I'm really beginning to question if you've ever actually been involved in electronics as you've claimed. This isn't hard stuff, yet you seem to be ignoring obvious facts in some quest to be proven right...reality be d_mned. I mean seriously, I don't know how you can claim with a straight face some of the stuff you are saying when it is the basis of how just about every day-to-day device works (OTA digital tv, digital cable, 3G, etc). At its simplest, you have a carrier wave and a QPSK/QAM-encoded data overlay (I'll ignore the spread-spectrum aspect for simplicity). You change the carrier wave to match what "channel" you want to transmit on (which corresponds to a specific frequency, just like with your TV). You mux in your data...out it goes through the antenna. That's it. You can change the carrier wave to correspond to different channels (which, in turn correspond to different physical frequencies TO BE DYNAMICALLY TUNED TO). That's how you access different channels from a given "band"...and if another band's channels overlap the radio's physical capabilities to the point that the radio can access all of them too...guess what? THE RADIO CAN TUNE TO THEM ALSO IF TOLD TO DO SO. That's what makes the 2100 radio workable in both markets....BECAUSE IT CAN TUNE TO THE WHOLE RANGE OF FREQUENCIES REPRESENTED BY BOTH BANDS. Is that clear enough?

The assertion that a UMTS RADIO has a hardware based limitation (eg built into the transistors of the IC) of channels it can access is ludicrous. Really. And yes, I stand by my statement that there is no basic difference in the UMTS 2100 bands (I and the DL portion of IV). If you would bother to actually READ the chart you helpfully linked for me, you'll see that the IV band is a completely contained SUBSET of "I". Therefore, if a radio can tune to the entirety of Band I, Band IV is also accessible *BY DEFAULT* given proper firmware/software and the corresponding 1700 uplink. In terms of the N900...since it costs more money to make multiple SKU's, it is in Nokia's best interests to provide the aforementioned proper firmware/software so that the N900 will work in both markets. Period. End of Story. This isn't some specially-cooked UMTS chip just for this niche application..this is a firmware issue that happily matches with harmonized market frequencies to leverage hardware.

If you mean that the semiconductor company programs the UMTS chip at the time of manufacture, then I don't disagree. The point is that when Nokia uses a UMTS chip in a device, it cannot, through software, change the chip's frequencies at will to any frequency it wants.

yes, nokia can...within the frequency range that the radio on said chip is physically optimized for. This frequency range is a CONTINUUM with a start and end frequency as defined by the various components of the analog RF circuit....and is *not* an immutable discrete set of single frequencies (ie channels) that are burned into the chip. While it is not *impossible* to have such a burned-in scenario..it simply doesn't make economic sense to do so for the reasons I have laid out over and over and over. Instead..........
...
<takes a deep breath>

These things HAVE FIRMWARE. THEY CAN BE CHANGED. One more time for the cheap seats: These things HAVE FIRMWARE. THEY CAN BE CHANGED. The semiconductor fabs don't "program them" for specific bands because that's not how it works. You don't "program" chips like this in hardware...you put a bit of flash on them to store FIRMWARE. (since you asked...it is THIS POINT that I was trying to give you the background for by explaining the high-level fab process. If you don't understand how the chips get made, you won't understand the motivation behind some of the design decisions..and it's clear you are missing both) You *could* do it with FPGA's..but that would be just dumb given the cost difference. Now what they *can* in fact accomplish at that level of manufacturing (depending on how integrated it is) is determine what frequency range the system is optimized for. But that is not the same as enumerating the individual channels it is capable of tuning to. If you can't make that distinction, you'll never understand how this stuff works.

For example:
http://www.modaco.com/content-page/277346/re-dumped-i900l-triband-3g-brazilian-rom/page/100/

Where they are working on something that you've claimed numerous times is impossible. While they haven't been fully successful in their overall goal..the fact that they have been able to extract the radio ROM from a 3G phone, see (though decompilation debugging tools) the references to the 3G bands and channels..and they've been able to flash the radio should be a good enough proof of concept to show that I'm not just some raving lunatic pulling random ideas out of the air here.

Here's another effort that seems to be more successful:
http://www.telesphoreo.org/pipermail/g1-hackers/2009-May/001494.html
">>>> Hi alls,
>>>> I just discovered i can cheat :)
>>>>
>>>> I can give the Tmobile G1 900hz umts coverage just by splicing the htc
>>>> magic firmware,
>>>> :) Mu ha ha ha ha etc
>>>> and im looking at other frequencies that could be "Enabled" so
>>>> possibly soon there could be a "haxxed" firmware to allow a plethora
>>>> of UMTS freqs
>>>>
>>>> If anyone wants a specific frequency please reply to this
>>>> so far,
>>>> it looks possible / easy
>>>> to enable
>>>> 900mhz (can be inserted via the HTC Magic firmware)
>>>> 850mhz (can be inserted via the rodgers canadian firmware)
>>>> 1900mhz (this one looks rediculasly easy to enable, as it is already
>>>> in the firmware :P, i just need to find where it is being stopped in
>>>> the firmware and "change" it :) )
>>>>
>>>> Anything else should be possible :)
>>>> Screw Dual Band :P
>>>> I want more bands then my network provider even have :P
>>>>
>>>> At current i have been inserting the new firmware via the oemspl loader
>>>> if anyone can think of a better way to insert it please give me a yell :)
"

I mean, seriously, if you think that Nokia went to TMC (or whatever fab they use) and asked for a lot of chips that were special-made to "allow" the 3 bands via channel enumeration hard-coded into transistors included on the N900....well, you be smokin' the wacky weed, my friend. Now, the *controller* that actually initiates the physical tuning action could have some sanity checks depending on the implementation (I would imagine all the new ones probably do) such as must be in multiples of 200khz, don't exceed a certain min/max frequency, but again..that's not the RADIO.

As long as the physical parts (antenna, ocillator circuit) match up for the frequency range desired...yes, nokia (or someone who can reverse-engineer the radio ROM and re-flash it with modified code as the crafty folks I linked to above) could change it to anything they wanted (that passed whatever sanity checks that were in place). However, if they wanted it to, you know, WORK on existing networks, they would be wise to use frequency channels that correspond to those used by the towers in their area.

p.s. I'm not trying to give you a hard time personally. The problem is that when you say something like the radio frequencies are "tunable by software", there will be many people who get the misimpression that Nokia could change the frequency incompatibilities of the N900 through software.

I appreciate that...and please excuse my exasperation as I'm not intending to be condescending nor combative. But unfortunately (for your argument), that's exactly the case. With the caveats that I've listed (over and over and OVER) ie if the antenna and oscillator/amp circuits are compatible with the "new" frequency...nokia could EASILY change them to anything they wanted via software. If the antenna and/or oscillator circuits do *not* match up..then no...a software update would not be enough (one of the brazillian guys from above found that out the hard way..he changed his radio via SOFTWARE to a frequency that wasn't supported and zapped his 3g access LOL). A near-perfect example of this was with the recent U.S. launch of the 5800 where the 3G didn't work in Chicago or New York due to lack of 3G channel information in those markets. Affected devices had their radios flashed in a panic service recall...and voila...up and running. If it had been a hard-coded hardware issue..either the event would have never happened OR would have required a complete replacement to fix (at the cost of considerable time since a new custom order of chips would have to be made...circuits designed, masks created, etc).

Another "realistic" scenario is if a new country came into the fold with channel designations not taken into account at launch (but were in a compatible frequency range of the N900's 3g radios in some combination ie 900,1700,2100...lets say Band X to give a concrete example), nokia could patch the radios to work in this new market without requiring all new RF hardware. However, a software update is NOT likely to be sufficient to access the 850/1900 3G services of AT&T (850 *might* be achievable depending on how wide the frequency response range of the 900 radio is, but I wouldn't hold my breath for moving 2100 to 1900 or 1700 for 1900 as that's getting pretty far off the mark from the original design centerline freqs).

As another example, please check out the following product spec sheet:
http://www.ent.eet-china.com/PDF/2007FEB/DTCOL_2007FEB15_AVDE_RFR_AN_01.pdf

You'll notice that at the bottom there are the various options of frequency combinations available in the RF chipset configuration. Note that ONLY frequencies "blocks" are listed..not Bands. The tuning details are left to firmware/software.

Now, with ALL of that said, you can be forgiven if you are basing all of your assertions on whatever experience you claim in the WiMax field. I don't know much about the chipsets and such for them...they may very well have burned-in hardware channels since at this point they are very specialized and truly just one step above the prototype stage IMHO...but then again WiMax doesn't have the disparate frequency bands to serve all the different markets that GSM/WCDMA must contend with. In that case, it might make sense (especially in this relatively early phase) to cook things in rather than having to deal with a firmware layer that must be written/debugged if they are trying to get stuff out the door quickly. But as I've demonstrated, that's not the reality of the phone world....and eventually (assuming wimax catches on world wide) it will be the reality of wimax as well if it isn't already.

Anyway, I'm done. For more information sit on a couple IEEE task forces or join an IC design team ;)

ruskie

2009-09-13, 08:07

This has been a very interesting read. I only know a bit of electronics but I can understand the distinction between a radio and it's frequency range and the rest of the stack above that, that would control what can be actually done. As for software controlled don't think software and firmware. They are the same thing. Both are software so yes it is software controlled in the end. The only difference is where they run and how they are coded up.

I hope I haven't given any more confussion to this thread.

christexaport

2009-09-13, 10:52

SD69, I'm not sure its true, but I remember HTC had the 850 frequency locked in some WinMo devices, and the xda devs unlocked it, so its possible, but I have no idea myself.

christexaport

2009-09-13, 11:32

I really appreciate you guys. I totally understand the story now. We get frequency and channel mixed up. From the looks of things, 2100 supports both bands, and the device caters to far more people than I originally assumed. It also tells alot about Nokia's faith in the growth of the at&t network.

Either way, now kenny and I know the facts, and we can stop arguing about this. I think texrat cleared it all up, and I'm moving on.

BTW, Kenny, you assumed I meant N900 in one post, but I'd editied it to 900 MHz. Sorry for the confusion.

BadMojoUT

2009-09-13, 12:12

@texaslabrat: perhaps I should invert the question..

If the N900 (for some reason) are in fact outfitted with different radio for different region (ie: nam vs rest of the world), wouldn't they carry different model number\mark of distinction?

texaslabrat provided a guess in the affirmative but I thought I'd just confirm it. The answer is yes, if there are different radio configurations (and to an extent, software configurations), Nokia designates them with different labels.

For instance:

Original Euro/Asia N95-1 = RM-159
NAM N95-3 = RM-160

Euro/Asia N86 = RM-484
NAM N86 = RM-485
China N86 = RM-486

Euro/Asia N97 = RM-505
China N97 = RM-506
NAM N97 = RM-507

This is why when some people were saying that ordering an N900 from an importer would result in an EDGE only experience with T-Mobile USA, it was just plain bogus. The N900 that passed through the FCC had a model designation of RX-51 and was tested on the AWS bands. The N900 previews that had been popping up on the web (mostly from European sites) all had the RX-51 labeled clearly on the device as well. So in other words, there was no "NAM" specific N900 that you had to buy to get 3G on T-Mobile USA. The only reason you'd want to buy a "NAM" version was because of return/exchange/warranty purposes. My experience with Nokia USA is that they won't honor the warranty on a device purchased abroad.

kenny

2009-09-13, 14:36

I think texrat cleared it all up, and I'm moving on.

BTW, Kenny, you assumed I meant N900 in one post, but I'd editied it to 900 MHz. Sorry for the confusion.
Chris, I assumed you meant N900 because you typed N900. And btw, it's texaslabrat on this thread, not texrat......he's another guy (who I think you know.)
Anyway, SLOW DOWN man, you're supposed to be a journalist. There's enough confusion surrounding the NITs already. As you know, this forum is and has been the place for answers......but it's often a long process. There tends to be a rather low signal-to-noise ratio here with a lot of newbies, a lot of guesses, a lot of un-knowledgeable "facts", etc.
.
Also, could you still please clear up my confusion concerning your posts in that other thread ? See post #98: http://talk.maemo.org/showthread.php?t=31284&page=10that

ysss

2009-09-13, 15:18

texaslabrat provided a guess in the affirmative but I thought I'd just confirm it. The answer is yes, if there are different radio configurations (and to an extent, software configurations), Nokia designates them with different labels.

For instance:

Original Euro/Asia N95-1 = RM-159
NAM N95-3 = RM-160

Euro/Asia N86 = RM-484
NAM N86 = RM-485
China N86 = RM-486

Euro/Asia N97 = RM-505
China N97 = RM-506
NAM N97 = RM-507

This is why when some people were saying that ordering an N900 from an importer would result in an EDGE only experience with T-Mobile USA, it was just plain bogus. The N900 that passed through the FCC had a model designation of RX-51 and was tested on the AWS bands. The N900 previews that had been popping up on the web (mostly from European sites) all had the RX-51 labeled clearly on the device as well. So in other words, there was no "NAM" specific N900 that you had to buy to get 3G on T-Mobile USA. The only reason you'd want to buy a "NAM" version was because of return/exchange/warranty purposes. My experience with Nokia USA is that they won't honor the warranty on a device purchased abroad.

Thank you very much.

I'm a simple guy, I'll just try to find obvious markings from the producers (like what you've confirmed above) to find out whether there may be difference in spec\capability between products. If the SKUs are the same, then they should have same product inside :)

SD69

2009-09-13, 17:20

a channel is simply a LABEL for a given frequency (it is actually mathematically derived FROM the frequency, in fact, via a formula in the standard) . It is a swath of bandwidth with a centerpoint frequency. If you tell your radio to tune to "channel 1096", it will look at you funny. Instead, you tell it to tune to 2135.6 Mhz (or whatever..pulling numbers out of the air here). Can't channels be different because they have a different centerpoints, bandwidth and guard bands, even though the same frequency falls within both channels?

Plus, you asserted that the software can tell the radio to tune to any arbitrary frequency "XYZ". It can select channels by tuning to the 2135.6 MHz centerpoint of the channel, but it can't tune the chip arbitrarily to 2139 MHZ. Again, this is AFAIK

The assertion that a UMTS RADIO has a hardware based limitation (eg built into the transistors of the IC) of channels it can access is ludicrous. :confused: Of course, I didn't say that. I'm talking about the chips (and you're talking about the radios). Let's keep the focus on the chips that the semico delivers and the extent to which Nokia can control them via software. I don' think there are any UMTS chips that Nokia, via software, can control to tune to some arbitrary frequency. Again, pls feel free to point out any such UMTS chip.

For example:
http://www.modaco.com/content-page/277346/re-dumped-i900l-triband-3g-brazilian-rom/page/100/

While they haven't been fully successful in their overall goal..the fact that they have been able to extract the radio ROM from a 3G phone, see (though decompilation debugging tools) the references to the 3G bands and channels..and they've been able to flash the radio should be a good enough proof of concept.

Here's another effort that seems to be more successful:
http://www.telesphoreo.org/pipermail/g1-hackers/2009-May/001494.html

Ummm... These don't support your main assertion, only the sub-assertion (which I've never disputed) that the UMTS chips have firmware that can be reflashed. Here there is not even a claim to be able to control the tuning of the UMTS chip via software; only to unlock the bands which it seems that the chip provider disabled for some reason or another. Whether either of these attempted hacks even worked to that extent seems unclear.

And I don't see how they show how an OEM like Nokia can tune the UMTS chip to some arbitrary frequency from the software stack.

For more information sit on a couple IEEE task forces or join an IC design teamYes, please feel free to cite some IEEE Communications Society material, or better yet, just link to any commercially available UMTS chip which can be tunable by the software stack.

SD69

2009-09-13, 17:32

SD69, I'm not sure its true, but I remember HTC had the 850 frequency locked in some WinMo devices, and the xda devs unlocked it, so its possible, but I have no idea myself.Yes, I've read about stuff like that. It is always unfortunate when devices or components get crippled. Unfortunately, once the chips have been contracted, an OEM like Nokia has no ability to overcome such measures but I would hope that Nokia would not deal with vendors that offer crippled technology.

texaslabrat

2009-09-13, 18:33

Can't channels be different because they have a different centerpoints, bandwidth and guard bands, even though the same frequency falls within both channels?

Yes they can. But the physical radio doesn't know about it...it only cares about the frequency with which to oscillate the antenna. The mapping of channel->frequency happens higher in the stack. And the choice of what channel to use happens even further up the stack than that.

Plus, you asserted that the software can tell the radio to tune to any arbitrary frequency "XYZ". It can select channels by tuning to the 2135.6 MHz centerpoint of the channel, but it can't tune the chip arbitrarily to 2139 MHZ. Again, this is AFAIK

The software *CAN* tell the radio to tune into any arbitrary frequency, though there are some caveats provided by the WCDMA specs that must be followed. The main one is that everything must be in multiples of 200khz. That, plus the absolute min/max frequencies supported by the hardware, are pretty much it as far as the RF chip is concerned. Again, the other constraints are imposed further up the stack (such as the begin/end frequecies of the band that the phone is trying to communicate in...which is controlled by a firmware-enabled SoC).

:confused: Of course, I didn't say that. I'm talking about the chips (and you're talking about the radios). Let's keep the focus on the chips that the semico delivers and the extent to which Nokia can control them via software. I don' think there are any UMTS chips that Nokia, via software, can control to tune to some arbitrary frequency. Again, pls feel free to point out any such UMTS chip.

Um, all of them currently shipping today? That's the whole point I've been trying to demonstrate..the channel-frequency mappings are in firmware that can be modified. People have done it..this isn't theory. I have given you examples of where this very thing that you claim to be impossible has actually been accomplished. If the "allowed" frequencies were hard-coded into the hardware IC, there would be no reason for them to be enumerated in firmware which can be modified, now would there? If the "allowed' frequencies were hard-coded in hardware, the U.S. 5800 3G launch issue would have turned out very different.

Ummm... These don't support your main assertion, only the sub-assertion (which I've never disputed) that the UMTS chips have firmware that can be reflashed. Here there is not even a claim to be able to control the tuning of the UMTS chip via software; only to unlock the bands which it seems that the chip provider disabled for some reason or another. Whether either of these attempted hacks even worked to that extent seems unclear.

Many of them have been successful as I (and others) have pointed out.

And I don't see how they show how an OEM like Nokia can tune the UMTS chip to some arbitrary frequency from the software stack.

Because they can write the firmware which controls the tuning functions. These things are not "black boxes" in inmutable silicon...they are small computers on SoC packages. The SoC talks to the RF chip via a serial interface which sends commands and data to the portion which converts the signal to an analog wave (and tunes the radio) for transmission out the antenna (or conversely tunes the radio to await a signal from the tower). If you look at the SoC "computer" part, you'll notice that it is an ARM-based computer with it's own firmware stack separate from the ARM-based computer that runs the user-facing software. It is here that the tuning decisions are made and where the DSP lives that handles all the complicated decoding/encoding stuff. In my example that I linked in the prior post..this portion would be a Qualcomm PM7500 which is serially connected to the radio (RF chip) of varying types depending on the frequency ranges one wants to support (eg RTR6275/RFR6500..etc)

Yes, please feel free to cite some IEEE Communications Society material, or better yet, just link to any commercially available UMTS chip which can be tunable by the software stack.

I did...I might have included it via edit after you started this response...check out my latest thread again.

I mean, if you are just trying to be pedantic about the whole thing..then yes you are right. The radios are restricted to tuning to certain frequencies because the raster spec of 200khz so tuning to 2110.111 Mhz would not be allowed because it is not a smooth multiple of 200khz. However, what you keep missing is the radio itself is COMPLETELY oblivious to the label that we have assigned a given frequency. This means that the radio is fully capable of tuning into "fractional" channels since such fractional channels are allowed by the WCDMA spec even if they might not exist in practice by being deployed by a service provider. So, if you are trying to say that, through following the WCDMA spec, that by default every possible channel allowed by the spec is "burned into the silicon" due to the restrictions imposed by the raster and the min/max frequencies of the various bands..then sure I guess you could claim that..though the safeguards in place from one controller to another might vary so you would have to looks at each individual design case-by-case to veryify it wasn't implemented in firmware instead.

But instead what you SEEM to be claiming is that there is some hardware-based database of channels (and I mean "channels", as in the derived labels, and not the physical frequencies) in use in each market that the phone is restricted to tuning to..and that's simply not true as has been demonstrated through decompilation of radio firmware. Further, the choice to utilize "BAND IV" channels is a firmware issue if the radio is already spec'd for "BAND I" as long as the corresponding 1700 radio is also present in the system. There isn't a special version of the 2100 radio that is "band iv capable" versus a 2100 radio that is "only band I capable". If *that* is your argument..you are dead wrong. Sorry...nobody is going to invest in creating millions of "BAND I ONLY 2100Mhz" radios, and in a separate bin have "BAND I + IV 2100 Mhz" radios when one part can do both jobs. That would just be bad business and, as I've pointed out, fabs make their money through volume and scale..having 2 sku's that are capable of the same job is a loser. They are one single part that gets used in various system configurations to support the bands a given phone is meant for. Now..are there hardware restrictions (ie burned into the IC design) in the controller chip that would prevent tuning to some undefined channel outside of known bands or that didn't follow the frequency raster constraint? Say a new band that has a frequency range outside of any existing UMTS band class. That I won't argue either way since I'd have to be on the design team to know for sure...and both "yes" and "no" are plausible since such restrictions could be implemented anywhere the designers saw fit (hardware or firmware). But that's not what we're dealing with here...we're dealing with chips that are aware of the full breadth of frequencies in use in terms of blocks of continuous spectrum and have connections to radios that have, in turn, the appropriate analog components to be able to utilize those frequencies.

So I guess all this really comes down to the fact that, although it could theoretically exist, you can't BUY a "BAND I Only 2100Mhz" UMTS radio for use in conjunction with a UMTS SoC. They don't exist through volume suppliers like Qualcomm. What you CAN buy is a "2100Mhz" UMTS radio. You then program the controller to use the appropriate channels for your market via firmware. If you have also selected a 1700Mhz radio for your system, then you can add the Band IV channels to the mix and tell your controller, via firmware, that they are fair game. Likewise, you can't BUY a "BAND I Only" UMTS controller versus a "BAND I + IV" controller as dictated by customized transistor circuits. They don't exist (these days, anyway). You can buy an integrated package of a generic UMTS controller included with frequency-appropriate RF chips (ie radios) and you program it with firmware to talk to the networks you are interested in (ie which bands you plan to connect to in the markets the product is intended for).

As has been demonstrated by our Brazilian friends..you can try and tell your radio, via firmware, to use frequencies that there is no analog hardware for. The controller will happily comply..but the analog portion isn't designed for it so in the end it fails to connect. If all of that isn't proof enough for you, then I suppose you just can't be convinced of the facts. Tilt on, Mr. Quixote...Tilt on!

ruskie

2009-09-13, 18:53

I'm thinking the main confusion is that some people think that firmware != software... that is wrong...

Firmware is Software just runs on a different level.

Suurorca

2009-09-13, 19:21

This has been very amusing read, ty guys.

I can for the very least confirm that Euro 2100 Nokias work perfectly well in Asian network - if you can get a local SIM. In japan, for example, they apparently do not sell phones without contracts at all et vice versa.

What confuses me however is, why some models, even in the more expensive price segment, have more frequencies than others. What's the point? And why is it always either/or with 850/900? Too close to each other? Seems weird....

kenny

2009-09-13, 19:50

I just want to interject a huge THANK YOU to both Texaslabrat and SD69 for taking the effort and a lot of time to conduct this discussion. It is very informative and I'm sure that many of the NIT fanatics here appreciate this kind of knowledge. Also, big kudos for retaining composure and replying in a civil manner.....civil engineers??:rolleyes:
.
On a side note, (just call me stupid), how do you get the quoted sections of a reply to break up into pieces so you can address a post piece by piece? Examples would be posts #47 and 49.

Crashdamage

2009-09-13, 20:10

...THANK YOU to both Texaslabrat and SD69 for taking the effort and a lot of time to conduct this discussion.
Second that notion.

...how do you get the quoted sections of a reply to break up into pieces so you can address a post piece by piece?
I just do it manually. When you post a reply with a quote, notice the quote starts with 'quote' in brackets, and ends with '/quote' again in brackets.

Note I can't put the brackets there or part of that line shows up as a quote. Just look at a quoted reply you're writing to see what I mean. Anyway, I just add those where I need 'em. Works for most (but not all) forum software.

texaslabrat

2009-09-13, 21:51

What confuses me however is, why some models, even in the more expensive price segment, have more frequencies than others. What's the point? And why is it always either/or with 850/900? Too close to each other? Seems weird....

Seems to be a purely business-driven decision rather than a technical one. There are quad-band UMTS modem cards available. For instance:
http://www.option.com/en/products/products/wireless-data-cards/ge0441/specifications/#start

BadMojoUT

2009-09-13, 22:42

Seems to be a purely business-driven decision rather than a technical one. There are quad-band UMTS modem cards available. For instance:
http://www.option.com/en/products/products/wireless-data-cards/ge0441/specifications/#start

Yeah, to further this point, the problem with large manufacturers like Nokia is that it seriously takes a while for them to steer their ship. Their massive size, while a great strength, is also their greatest weakness. Because of their size, they have great reach, can realize economies of scale, and can produce handsets for just about any segment of the market. However, because of their size, they aren't all that nimble.

Look at how long it's taken Nokia to adopt the OMAP3430 platform. Samples of that came out in the middle of 2006 and went into volume production next year. And now we're finally seeing products using this (the Pre, iPhone 3GS, N900).

So aside from samples being available so that you can actually design your products around them, the other main issue is volume. Nokia isn't interested in manufacturering products in the tens of thousands (unless we're talking about the Vertu but that's a different story). They're usually looking at least in the millions if not tens or even hundreds of millions in order to get the best possible pricing. And that's from one manufacturer! Imagine that you're a foundry and you had to fulfill orders with such magnitudes. Clearly, in order for you to be able to adequately supply such parts to your customers, there needs to be time to ramp up production.

So yes, it sucks that we have to wait a while but those are the realities of product development and supply chains. I've been dreaming of a quad-band 3G since 2006 but we'll just have to wait a little while longer.

TECHDUCK!

2009-11-16, 14:08

Gentlemen,

Based on the followings:

Mobile City Online: http://www.mobilecityonline.com/wireless/store/search.asp?keywords=n900&Submit=Go; the specs for the N900 are; “Nokia N900 Mobile Computer Unlocked Import: Optimized for WCDMA 900//2100” AND “Nokia N900 Mobile Computer Unlocked US: Optimized for WCDMA 900/1700/2100”

Reply from: importgsm.com: “Unfortunately the N900 US version is not out yet. The only difference will be the 3G frequency and warranty region. GSM will work worldwide on both versions.
The US version will work internationally, and on T-mobile 3G in the US. The import version will work on international 3G only.”

Forgive my ignorance, put simply please..; regarding 3G, does this mean that the US version would be useable/cover the Europe and ”import” areas but the Europe ”import” version can only cover/ be used in Europe?

I assume quad band GSM would cover either market but I travel to both areas and was wondering which version to purchase to achieve the maximum on 3G?

fib11235

2009-12-28, 14:17

Has Nokia said anything about releasing a 3G 850/1900 band version (a US ATT customer here obviously, and can not switch for a year or so).

I realize that I can use the N900 via EDGE/GSM, but 3G would be nice.

Have been awaiting this device ever since I used my N770 back in the dark ages. :)

(Sorry if this has been discussed, but I have searched for an hour or so on this before posting).

andraeseus1

2010-04-13, 21:48

well with al lthe stuff we change and improve on around here @ maemo.org why cant some one change the frequency receiver in the n900 to work on both tmo and at&t or od it to use sprints network also or any variation u could imagine?> how hard would that be and is it possible?

hpons

2010-06-26, 00:58

In Venezuela and others countries, thousands Nokia N900 users can get 3G cause providers use 1900MHz UMTS (N900 can’t use). Adding the 1900 antenna could solve this limitation, hard? But possible: http://ceta.mit.edu/pierc/pier.php?paper=09070704
Any idea or suggestion?
Tks, Hector Pons

Baseband UMTS radio chips are much more complicated than FM chips and are not tunable by software across a continuum of frequencies. Currently, they can only operate on the pre-defined channels in a limited number of pre-defined bands. I have an engineering degree. I'm not guessing here.

Laughing Man

2010-06-26, 01:27