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Sprint talks 20 MHz TDD LTE carrier aggregation


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http://www.dailywireless.org/2013/04/22/sprint-carrier-aggregation-at-2-6-ghz/

 

 

In terms of LTE-Advanced features, Alston said that Sprint’s priority is for Band 41 carrier aggregation and not so much its Band 25-26 holdings (its FD-LTE service in the PCS band).

He said contiguous carrier aggregation is easier than non-contiguous, and that carrier aggregation between TDD and FDD can be contemplated, but “it’s not something we’re focused on at this time.”

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While carrier aggregation is beneficial for peak speeds, it does nothing for capacity. Additionally, the complexity it introduces at the basestation software might not be worth it. I'm still to be convince that carrier aggregation is good for anything but running speedtests at 3:00AM on unloaded channels and bragging rights.

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While carrier aggregation is beneficial for peak speeds, it does nothing for capacity. Additionally, the complexity it introduces at the basestation software might not be worth it. I'm still to be convince that carrier aggregation is good for anything but running speedtests at 3:00AM on unloaded channels and bragging rights.

 

DC-HSPA+ is pretty much the exact type of solution that LTE CA is, and it's doing quite well for T-Mobile. So I won't discount that yet. Having a bigger bonded pipe does indirectly affect capacity in a positive way (sort of like how it's easier to keep reasonable speeds on a less-efficient HSPA 7.2 carrier than it is on an EvDO one). Heck, take DOCSIS 3.0 from cable companies, or pair-bonded DSL from telephone companies.

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DC-HSPA+ is pretty much the exact type of solution that LTE CA is, and it's doing quite well for T-Mobile. So I won't discount that yet. Having a bigger bonded pipe does indirectly affect capacity in a positive way (sort of like how it's easier to keep reasonable speeds on a less-efficient HSPA 7.2 carrier than it is on an EvDO one). Heck, take DOCSIS 3.0 from cable companies, or pair-bonded DSL from telephone companies.

 

I thought that DC-HSPA+ and LTE CA devotes the same percentage of subcarriers to guard bands no matter whether you have 2 channels by themselves or two bonded channels. So where are the efficiencies going to come from?

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I thought that DC-HSPA+ and LTE CA devotes the same percentage of subcarriers to guard bands no matter whether you have 2 channels by themselves or two bonded channels. So where are the efficiencies going to come from?

 

If you can turn what would normally be sustained max'ing out of a pipe into bursty utilization of a larger pipe, the net experience on most data applications will be positive. It's traffic engineering/statistics, not math, that makes the difference here.

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I thought that DC-HSPA+ and LTE CA devotes the same percentage of subcarriers to guard bands no matter whether you have 2 channels by themselves or two bonded channels. So where are the efficiencies going to come from?

Mandatory 2x2 MIMO + OFDMA.

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That's mandated by LTE-Advanced and not by Carrier Aggregation.

It's actually been mandatory for LTE since Release 8 which improves spectral efficiency over DC-HSPA where MIMO isn't mandatory, and most operators don't bother deploying.

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It appears that after acquiring Clearwire, Sprint intends to make use of TD-LTE in a big way with two carrier aggregated 20Mhz TD-LTE channels.

 

Sprint Nextel (NYSE:S) aims to enable contiguous carrier aggregation (CA) over the TD-LTE Band 41 spectrum held by its partner Clearwire (NASDAQ:CLWR), according to a senior Sprint executive.

In fact, Sprint's priority is LTE-Advanced CA using Clearwire's 2.5 GHz spectrum rather than Sprint's own holdings in Bands 25 and 26, said Doug Alston, the carrier's director of technology and strategy, who was quoted by RCR Wireless.

His comments reflect the long-stated aims of Clearwire, which has said it intends to start offering LTE this summer with a 20 MHz channel in TDD-LTE Band 41, which encompasses 2496-2690 MHz spectrum. Clearwire expects to subsequently use intra-band continguous CA to combine its initial 20 MHz with another 20 MHz, creating a 40 MHz pipe at every sector that will be capable of vastly higher speeds and capacity than operators holding smaller amounts of spectrum can hope to offer. Clearwire holds around 120 MHz of spectrum in many U.S. markets.

 

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So, what's the maximum throughput of that puppy? 40 MHz is a lot of spectrum to be throwing at something.

 

Max downlink speed = 3.75* total bandwidth = 150mbps

 

Advertised/Average downlink speed = 0.6 to 0.8 * total bandwidth = 24 - 32 mbps

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I still think that two 20 MHz TD LTE carriers would be better served than to have one 40 MHz TD LTE carrier aggregated pipe. There is no need to have such fast speeds when Verizon, ATT and Tmobile are still deploying 10x10 LTE carriers.

 

The bigger question is where is Sprint and Clearwire going to build out the TDD-LTE network. Certainly we know it won't be on every single Network Vision site so either way the Clearwire TD LTE network will be limited.

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Max downlink speed = 3.75* total bandwidth = 150mbps

 

Ok, I'm following you here. But then...

 

Advertised/Average downlink speed = 0.6 to 0.8 * total bandwidth = 24 - 32 mbps

 

I'm not sure how you come up with these figures. :unsure:

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I'm wondering if sprint and Clearwire are going to install td LTE on the network vision platform or separate? If separate wouldn't that cause the same problem that iden caused with double site rent and double operating cost?

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I'm wondering if sprint and Clearwire are going to install td LTE on the network vision platform or separate? If separate wouldn't that cause the same problem that iden caused with double site rent and double operating cost?

 

They will be installing it on the same Network Vision platform they have now. The only thing different is that there will be new panels added and carrier cards for TD-LTE will be installed into the same cabinets. So there won't be double anything.

 

 

Sent from Josh's iPhone 5 using Tapatalk 2

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They will be installing it on the same Network Vision platform they have now. The only thing different is that there will be new panels added and carrier cards for TD-LTE will be installed into the same cabinets. So there won't be double anything.

 

 

Sent from Josh's iPhone 5 using Tapatalk 2

 

I asked because I keep hearing about Clearwire already working on their network and I always assume that it wasn't apart of nv and was wondering how they were going to integrate it.

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