What data speeds are you getting?

[jbjtkbw007]

tl;dr -- a one gallon container only holds one gallon, no matter how fast you pour the water in.

Exactly, but iamlilysdad put it best. Also, you guys can watch the Q&A right from the horse's mouth which alludes to a bit of why this will happen here:

http://www.tmonews.com/2011/01/t-mobile-question-and-answer-session-after-ces-2011-press-event/

 

[anon62607]

Exactly, but iamlilysdad put it best. Also, you guys can watch the Q&A right from the horse's mouth which alludes to a bit of why this will happen here:

T-Mobile Question And Answer Session After CES 2011 Press Event | TmoNews - Unofficial T-Mobile Blog - News, Videos, Articles and more

They don't answer anything there, and what they do say matches exactly what I've said so far. MIMO isn't supported on the uplink in HSPA, and thus is still limited to 5.6 mbps. They kind of dodge the question about handsets supporting 21 and 42 mbps but for current handsets they only say that it's backwards compatible - which of course it is, but that doesn't change that the handset is only able to receive a certain maximum bitrate from a tower. A Nexus S is never going to receive more than 7.2 mbps payload (or 9.6 mbps payload + error bits) from the tower, it's radio just can't do it. The upgrade to 42 mbps (be it MIMO + 64qam or dual carrier + 64qam) doesn't change that the Nexus S (for example) simply cannot receive more than 7.2 mbps.

 

[Jerry Hildenbrand]

Exactly, but iamlilysdad put it best. Also, you guys can watch the Q&A right from the horse's mouth which alludes to a bit of why this will happen here:

T-Mobile Question And Answer Session After CES 2011 Press Event | TmoNews - Unofficial T-Mobile Blog - News, Videos, Articles and more

Um, what I'm actually trying to say is that the current HSPA+ network maxes out the Nexus S at 7.2. It can't get any higher. Was trying to translate valeuche's post for non-engineer types

 

[anon62607]

Um, what I'm actually trying to say is that the current HSPA+ network maxes out the Nexus S at 7.2. It can't get any higher. Was trying to translate valeuche's post for non-engineer types

Thanks! A little more technical detail can be acquired from (and it's by no means engineer-level, anyone who can figure out how to dial a phone will understand this):
Academic Press, "3G Evolution HSPA and LTE for Mobile Broadband"
Wiley, "Evolved Packet Systems (EPS), The LTE and SAE Evolution of 3G UMTS"
(the above are widely available in ebook format)

an extremely simplistic view of Rev 5+ HSPA: http://www.adare.de/HSDPA -High Speed Downlink Packet Access.pdf (this is probably so simplistic as to not be useful for this discussion, but it's a good starter)

This qualcomm paper: http://www.telecomer.net/wiki/uploadfile/hsdpa_downlink.pdf

the all-important 3GPP TS 25.211: http://www.quintillion.co.jp/3GPP/Specs/25211-790.pdf (you can get it many places, but this works). Without a complete understanding of that document, people probably shouldn't be attending those t-mobile question & answer sessions because they won't be able to ask the proper kinds of questions to get a meaningful answer. It's also critical knowledge for internet forum discussion.

This talks about MIMO, DC and 64qam utilization in HSPA+, which is important reading in determining which possible methods that tmobile might use to get that claimed 42 mbps: http://www2.rohde-schwarz.com/file_12188/1MA121_02E.pdf

 

[Kevin OQuinn]

Just to keep this going (because I'm just like that ) a gallon will only hold a gallon, but if you can get that gallon filled faster the next gallon will get the water that much sooner. I guess my argument really only matters if the network is strained. The argument has always been that faster data will alleviate network strain because it will be able to get through requests that much faster. Is this still the case? Or has the tune changed?

 

[Kevin OQuinn]

Um, what I'm actually trying to say is that the current HSPA+ network maxes out the Nexus S at 7.2. It can't get any higher. Was trying to translate valeuche's post for non-engineer types

And just like the telco and cable companies do when the next upgrade to 42mbps happens they might actually max my phone out (and any other HSPA+ phone currently out).

 

[MattMJB0188]

So if someday T-Mobile increases data to 42 mb will this phone be able to receive that? What's the highest speed the mytouch 4g can see?

 

[Kevin OQuinn]

I'm assuming (from the reading I've done) it's 14.4mbps theoretical max.

 

[MattMJB0188]

I'm assuming (from the reading I've done) it's 14.4mbps theoretical max.

Then what is considered 4G? I know T-Mobile's 4G is not technically 4G? Is Verizon's LTE considered 4G or just fast 3G?

 

[Kevin OQuinn]

It depends on your definition of 4G. It can get technical. I'll post a little more in a few hours.

 

[anon62607]

I'm assuming (from the reading I've done) it's 14.4mbps theoretical max.

Observed bandwidth would be about 14.0 mbps:
2560 symbols per timeslot * 3 slots per frame * 4 bits per symbol (16qam) *(15/16) (spreading factor) *500 (frames per second) *(35/36) (code rate) = 14.0 mbps. In reality though about 15% of that is going to be used for IP overhead and the most you'll ever see out of speedtest for example would be about 12 mbps.

The webconnect rocket can use a higher order modulation (64QAM) and presuming that it's an HSPA+ tower it's connected to, it's highest theoretical max is 2560 symbols per timeslot * 3 slots per frame * 6 bits per symbol (64qam) *(15/16) (spreading factor) *500 (frames per second) *(35/36) (code rate) = 21.0 mbps.

At this point, it's hard to pin down an official technical description of what 4G is. The old definition had specific requirements for end user bandwidth and spectral efficiency (how many bits per Hz of spectrum used - anyone can get 100 mbps if they're given a GHz of spectrum (aside from filter and amplifier design) - ITU said that not only do you need to deliver 100 mbps, you have to do it using no worse than ... whatever it was, 2.2 bits/Hz or something).

That definition has fallen out, and now it seems to be just "it has to be better than 3G". I think a MIMO, dual carrier, 64QAM HSPA+ system would fairly qualify for 4G - almost even under the old definition which demanded 100 mbps theoretical to the end user.

 

[Kevin OQuinn]

And Sprint and Verizon use 4G because LTE and WIMAX are "next generation" network technology. T-Mo and AT&T are going based solely on speed.

 

[anon62607]

Then what is considered 4G? I know T-Mobile's 4G is not technically 4G? Is Verizon's LTE considered 4G or just fast 3G?

Under the old definition:

Verizon's LTE (10+10 MHz FDD) was not 4G
Sprint's WiMax (10 MHz TDD) was not 4G
T-Mobile's HSPA+ (5+5 MHz FDD) was not 4G
Sprint's and Verizon's EVDO (1.25 Mhz) was not 4G
Revision 10 LTE (not deployed anywhere yet and won't be for years) IS 4G
WiMax 2 (also not deployed anywhere yet) IS 4G

under the relaxed definition:
Verizon LTE is 4G
Sprint's WiMax is 4G
T-Mobile's HSPA+ (even as it is now, before any further upgrade) is 4G
Sprint's and Verizon's EVDO is not 4G

So far as I can tell, there are no current spectral efficiency requirements to pinning the 4G label on yourself. I think the ITU engineers involved just threw their hands up when they saw all the marketing going on and said "whatever".

 

[anon62607]

Then what is considered 4G? I know T-Mobile's 4G is not technically 4G? Is Verizon's LTE considered 4G or just fast 3G?

To go a bit further, and without there being a hard definition for it, in HSDPA land it seems that category 8 devices are being called "3G" and category 10 devices are being called "4G". The point appears to be somewhere faster than 7.2 mbps and slower than 14.0 mbps.

Once tmobile upgrades to 42 mbps, and once it has devices that are using the data modes that the 42 mbps upgrade provides, the performance of those devices is, I suspect, going to be pretty close (maybe 85% of) what Verizon LTE users see on their 10+10 FDD LTE network. LTE will probably get closer to theoretical maximums more often than HSPA+ will, particularly on the bands that each are deployed on, but HSPA+ should remain a strong competitor for some time.

However, the maximum performance you'll ever see out of a myTouch 4G isn't going to change with the 42 mbps upgrade - it's going to stay at 14 mbps theoretical and about 12 mbps realistically.

 

[anon62607]

And Sprint and Verizon use 4G because LTE and WIMAX are "next generation" network technology. T-Mo and AT&T are going based solely on speed.

Indeed. LTE can be deployed with as little as 1.25 MHz of spectrum. Even theoretical best case in that situation is 6.25 mbps which wouldn't often be seen in real life. Just because it's a next generation technology doesn't mean it'll always be faster than current generation technology and if you had a theoretical deployment of LTE in 1.25 MHz in the US it'd be beaten by just about all 3G systems out there.

On the other end of the spectrum (heh heh), Clear has been demonstrating LTE in 20+20 FDD mode in the 2.5 GHz bands and observed 90 mbps with about 100 mbps as the maximum theoretical performance. I believe they're also testing LTE in 20 MHz TDD mode as well - there is a lot of speculation that in the future they'll offer four types of wireless: 20+20 FDD LTE, 20 TDD LTE, 20 TDD WiMax 2 and 10 TDD WiMax.

YouTube - Clearwire 4G LTE Trial Results <== clearwire LTE trials on 20+20 MHz FDD configuration.

 

[Kevin OQuinn]

To go a bit further, and without there being a hard definition for it, in HSDPA land it seems that category 8 devices are being called "3G" and category 10 devices are being called "4G". The point appears to be somewhere faster than 7.2 mbps and slower than 14.0 mbps.

Once tmobile upgrades to 42 mbps, and once it has devices that are using the data modes that the 42 mbps upgrade provides, the performance of those devices is, I suspect, going to be pretty close (maybe 85% of) what Verizon LTE users see on their 10+10 FDD LTE network. LTE will probably get closer to theoretical maximums more often than HSPA+ will, particularly on the bands that each are deployed on, but HSPA+ should remain a strong competitor for some time.

However, the maximum performance you'll ever see out of a myTouch 4G isn't going to change with the 42 mbps upgrade - it's going to stay at 14 mbps theoretical and about 12 mbps realistically.

Which for me is plenty fast. I'm still waiting for EXPANDED coverage. HSPA+ is not in my area yet. When it hits 42mbps here I might use that for home internet if that plans aren't ridiculous (I use a TON of bandwidth at home so it might not be feasible for me).

 

[MattMJB0188]

Under the old definition:

Verizon's LTE (10+10 MHz FDD) was not 4G
Sprint's WiMax (10 MHz TDD) was not 4G
T-Mobile's HSPA+ (5+5 MHz FDD) was not 4G
Sprint's and Verizon's EVDO (1.25 Mhz) was not 4G
Revision 10 LTE (not deployed anywhere yet and won't be for years) IS 4G
WiMax 2 (also not deployed anywhere yet) IS 4G

under the relaxed definition:
Verizon LTE is 4G
Sprint's WiMax is 4G
T-Mobile's HSPA+ (even as it is now, before any further upgrade) is 4G
Sprint's and Verizon's EVDO is not 4G

So far as I can tell, there are no current spectral efficiency requirements to pinning the 4G label on yourself. I think the ITU engineers involved just threw their hands up when they saw all the marketing going on and said "whatever".

To go a bit further, and without there being a hard definition for it, in HSDPA land it seems that category 8 devices are being called "3G" and category 10 devices are being called "4G". The point appears to be somewhere faster than 7.2 mbps and slower than 14.0 mbps.

Once tmobile upgrades to 42 mbps, and once it has devices that are using the data modes that the 42 mbps upgrade provides, the performance of those devices is, I suspect, going to be pretty close (maybe 85% of) what Verizon LTE users see on their 10+10 FDD LTE network. LTE will probably get closer to theoretical maximums more often than HSPA+ will, particularly on the bands that each are deployed on, but HSPA+ should remain a strong competitor for some time.

However, the maximum performance you'll ever see out of a myTouch 4G isn't going to change with the 42 mbps upgrade - it's going to stay at 14 mbps theoretical and about 12 mbps realistically.

Indeed. LTE can be deployed with as little as 1.25 MHz of spectrum. Even theoretical best case in that situation is 6.25 mbps which wouldn't often be seen in real life. Just because it's a next generation technology doesn't mean it'll always be faster than current generation technology and if you had a theoretical deployment of LTE in 1.25 MHz in the US it'd be beaten by just about all 3G systems out there.

On the other end of the spectrum (heh heh), Clear has been demonstrating LTE in 20+20 FDD mode in the 2.5 GHz bands and observed 90 mbps with about 100 mbps as the maximum theoretical performance. I believe they're also testing LTE in 20 MHz TDD mode as well - there is a lot of speculation that in the future they'll offer four types of wireless: 20+20 FDD LTE, 20 TDD LTE, 20 TDD WiMax 2 and 10 TDD WiMax.

YouTube - Clearwire 4G LTE Trial Results <== clearwire LTE trials on 20+20 MHz FDD configuration.

Thanks for clearing that up for me. So when they do hit 42mbps I am sure they will need to make new supporting devices? Bet they'll label these 5G phones lol.

 

[anon62607]

Which for me is plenty fast. I'm still waiting for EXPANDED coverage. HSPA+ is not in my area yet. When it hits 42mbps here I might use that for home internet if that plans aren't ridiculous (I use a TON of bandwidth at home so it might not be feasible for me).

I don't think wireless for home internet service is a realistic solution long term. We only have one electromagnetic spectrum and there's only so much of it to go around over the air. When you have a cable to your house, you are basically given a whole spectrum for you to use (well, you and your ISP) however you see fit. They can devote 200 MHz to it if they want to and can use higher order modulations to boot.

When you use wireless internet, you have to share your 5 or 10 MHz of spectrum with everyone else in the entire sector - which can be as many as 300 users on average in the US for a 120?, single band sector or about 100 users in the clearwire case (as they use 3x frequency sectors per geographic sector usually)

In the longer term future (say 8-10 years out) with very narrow beams / beam division multiple access where you effectively get 1 or 2 degree sectors, then it might be more possible.

 

[anon62607]

Thanks for clearing that up for me. So when they do hit 42mbps I am sure they will need to make new supporting devices? Bet they'll label these 5G phones lol.

I saw a slide from some chipset vendor's technical discussion (don't remember which one) that said exactly that. "Marketing will call it 5G". I believe the tone of the comment was that of a joke, but it wouldn't surprise me.

Yeah, Tmobile has said (I believe, from the Q&A video referenced earlier) that there will be supporting devices released in the nearish future.

That's probably one of the advantages of LTE phones at the moment, you don't have a giant minefield of varying capabilities. Just about every phone they will release should have a theoretical maximum of 50 mbps across the board and that matches the network. With HSPA+ the network is capable of one thing and there are a large variety of handsets all capable of different levels of performance within that - and it's clear from the discussion in this thread that consumers are terribly confused as to what they might actually get when they buy a given phone.

 

[anon62607]

Which for me is plenty fast. I'm still waiting for EXPANDED coverage. HSPA+ is not in my area yet. When it hits 42mbps here I might use that for home internet if that plans aren't ridiculous (I use a TON of bandwidth at home so it might not be feasible for me).

Yep. I just took a trip this last week from my home in Portland to Baltimore and then had to drive from there down to Bridgewater, Virginia. Portland has good HSPA+ coverage all around - I think I had gotten it into my head that everywhere must be like this. Of course as soon as you're 15 miles outside of town it does drop back to EDGE but as you get near to moderate sized cities you'd jump back up to HSDPA at least.

The drive from Baltimore, once past DC, was like a prehistoric backwater of technology. I had nothing but EDGE the entire way from just outside of DC to Bridgewater VA and the performance difference is pretty stunning. I'm pretty sure cavemen roaming around the neolithic eastern asian tundra had higher performing cell service. TMobile probably should, in general, bump up a few of their EDGE towers to the current level (21 mbps HSPA+) performance before they upgrade many of their 21 mbps towers to 42 mbps.

I had my rover puck with me too, which had no coverage at all aside from a hotel room in DC (just outside the IAD airport).