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AT&T may roll out a 100Mbps LTE Advanced network in 2013


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LTE Advanced doesn't really increase spectrum efficiency. It's mostly network-optimization features and carrier aggregation.

 

With better MIMO it does, by a lot too. 4x4 MIMO on LTE Advanced rel 10 is roughly twice as fast as 2x2 MIMO on the current LTE rel 9 network. So LTE Advanced 800 on Sprint should match LTE 700 on Verizon when the Sprint handset supports 4x4 MIMO.

 

However, 4x4 MIMO handsets may be a ways off and will probably be, (at least initially), terrible on battery life.

 

Speed of LTE 5x5 Mhz carriers at 4x4 MIMO = Speed of LTE 10x10Mhz carriers at 2x2 MIMO

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I would think that 4x4 MIMO support in handsets would be very limited. For tablets, etc, sure. But supporting multiple bands and having four antennas just doesn't sound feasible except with especially large devices. BRS would be the only one I'd expect to see anytime soon. Anyway, 4x2 (at least, maybe 4x4) MIMO is supported in Rel 8. LTE-Advanced isn't a prerequisite.

 

Edit: Does anyone know if Sprint's LTE hardware supports more than 2x2 MIMO as currently deployed?

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I would think that 4x4 MIMO support in handsets would be very limited. For tablets, etc, sure. But supporting multiple bands and having four antennas just doesn't sound feasible except with especially large devices. BRS would be the only one I'd expect to see anytime soon. Anyway, 4x2 (at least, maybe 4x4) MIMO is supported in Rel 8. LTE-Advanced isn't a prerequisite.

 

Edit: Does anyone know if Sprint's LTE hardware supports more than 2x2 MIMO as currently deployed?

 

The hardware supports 4x4. There is a video on youtube with Iyad Tarazi that explains a lot of this.

 

Sent from my SPH-L710 using Tapatalk 2

 

 

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Speed of LTE 5x5 Mhz carriers at 4x4 MIMO = Speed of LTE 10x10Mhz carriers at 2x2 MIMO

 

Careful. Both higher order modulation and MIMO are dependent on favorable RF conditions. And in many instances, RF conditions are not conducive to MIMO. So, 5 MHz FDD with 4x4 MIMO can equal 10 MHz FDD with 2x2 MIMO but does so only a statistical percentage of the time.

 

AJ

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4x4 MIMO in a smartphone is impractical to build and also, and speeds faster than what 2x2 MIMO produce are not needed in a smartphone. Those speeds will be for larger devices like tablets and maybe hotspots.

 

And as AJ points out, 4x4 MIMO will not really increase speeds in already slow parts of the LTE network. It won't improve speeds at the edge of cell or in buildings. It will only improve speeds in places already blazing fast.

 

For instance, in the Sprint network, 4x4 MIMO only would improve speeds in areas that are already 20-37Mbps (now up to 74Mbps max). So faster areas would get faster, but slow areas remain unchanged.

 

Robert via Samsung Note II via Tapatalk

 

 

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4x4 MIMO in a smartphone is impractical to build and also, and speeds faster than what 2x2 MIMO produce are not needed in a smartphone. Those speeds will be for larger devices like tablets and maybe hotspots.

 

And as AJ points out, 4x4 MIMO will not really increase speeds in already slow parts of the LTE network. It won't improve speeds at the edge of cell or in buildings. It will only improve speeds in places already blazing fast.

 

For instance, in the Sprint network, 4x4 MIMO only would improve speeds in areas that are already 20-37Mbps (now up to 74Mbps max). So faster areas would get faster, but slow areas remain unchanged.

 

Robert via Samsung Note II via Tapatalk

 

On the flip side, heavier MIMO usage has a similar effect to the TD-LTE overlay: customers closer to the base station use up a smaller percentage of available site capacity, thus making service better for everyone.

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Using the wcs spectrum they bought, right? I'm really interested to see the real world feedback the next carrier who uses this kind of spectrum to deploy a high speed data network receives.

 

Somewhere deep in the bowels of the AT&T headquarters, Randall Stephenson is sipping his chai and wringing his hands .... " more! I want more! Mooooore gigabytes... Look at them? They're beautiful! ".

 

Minion: "But sir, the technology has real world hurdles that only time can cure....the average user ....."

 

"Did I ask you? I went without sleep for almost three years.... laying in bed at night, my sphincter knotted tight, cringing in agony as gigabyte after gigabyte slipped away .... for what? for nothing! There's money to be made... Give them speed... Let them drink and eat and huddle around for the raw exhilarating speed! Faster ! Faster!"

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4x4 MIMO in a smartphone is impractical to build and also, and speeds faster than what 2x2 MIMO produce are not needed in a smartphone. Those speeds will be for larger devices like tablets and maybe hotspots.

 

And as AJ points out, 4x4 MIMO will not really increase speeds in already slow parts of the LTE network. It won't improve speeds at the edge of cell or in buildings. It will only improve speeds in places already blazing fast.

 

For instance, in the Sprint network, 4x4 MIMO only would improve speeds in areas that are already 20-37Mbps (now up to 74Mbps max). So faster areas would get faster, but slow areas remain unchanged.

 

Robert via Samsung Note II via Tapatalk

 

I thought MIMO 4x4 had, for lack of a better term, a beamforming effect and was more effective in increading speeds at the edge of coverage. I seem to remember something about it increasing speeds 100% at areas of lower signal strength while areas of strong signal might see a 50% increase in speeds.

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Somewhere deep in the bowels of the AT&T headquarters, Randall Stephenson is sipping his chai...

 

Chai??? Randall drinks nothing less than 18 year old single malt. Just look at the guy -- the blood that courses through his veins is clearly 80 proof.

 

AJ

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I thought MIMO 4x4 had, for lack of a better term, a beamforming effect and was more effective in increading speeds at the edge of coverage. I seem to remember something about it increasing speeds 100% at areas of lower signal strength while areas of strong signal might see a 50% increase in speeds.

 

MIMO and beamforming are two different techs, strictly speaking. Now base stations with 4x4 MIMO probably have beamforming built in, and beamforming does increase signal levels by multiple dB (translating directly into better LTE throughput), but it's not a direct side effect of just throwing more antennas/spatial streams at the problem.

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On the flip side, heavier MIMO usage has a similar effect to the TD-LTE overlay: customers closer to the base station use up a smaller percentage of available site capacity, thus making service better for everyone.

 

This is true, but I was using a benchmark of an unburdened network in my analysis in discussing throughput speeds. In such case, there would be no advantage. But your point is still valid if not considered in my discussion. :tu:

 

Robert via Samsung Note II via Tapatalk

 

 

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MIMO and beamforming are two different techs' date=' strictly speaking. Now base stations with 4x4 MIMO probably have beamforming built in, and beamforming does increase signal levels by multiple dB (translating directly into better LTE throughput), but it's not a direct side effect of just throwing more antennas/spatial streams at the problem.[/quote']

 

Hence the "for lack of a better term." I know it isn't beamforming, but it uses the antenna array to combine the signals, filter out "noise" and improve the signal to noise ratio, allowing a higher quality signal allowing more layers of signal (QAM) resulting in a higher transfer rate.

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so there is no difference between a 5x5 lte carrier and a 5x5 lte-A carrier ?

 

oh there is a difference. Mostly it's about getting higher speeds out of the current available spectrum if I get what i'm reading around here.

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There is a difference, but for all intents and purposes, the end user will not notice a difference on the downlink. Most of the benefits are related to interference management. Carriers will more easily be able to deploy microcells and femtocells in congested areas with the implementation of LTE advanced.

 

 

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Hence the "for lack of a better term." I know it isn't beamforming, but it uses the antenna array to combine the signals, filter out "noise" and improve the signal to noise ratio, allowing a higher quality signal allowing more layers of signal (QAM) resulting in a higher transfer rate.

 

Damn, Scott has been paying attention, and pretty soon, I may be out of a "job" as RF guru.

 

;)

 

AJ

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Something to think about? No matter how much AT&T cranks up the data, people will still be cautious because of overages. Heck 10 to 15 dollars per gigabyte would make me think about it.

 

Sent from my SPH-L710 using Tapatalk 2

 

 

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How significant is the range boosting effect of MIMO? Is the LTE airlink so fragile that it's still needs a 10 dBm stronger signal than CDMA technologies even with the effect of MIMO?

 

 

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