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[PSA] The holy LTE trinity. A third Band 41 carrier now going live!

lilotimz

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by Tim Yu

Sprint 4G Rollout Updates

Friday, April 8, 2016 - 3:40 PM MDT

 

Over the past week, S4GRU members in multiple Sprint markets have discovered new EARFCNs and corresponding GCI endings that identify new Band 41 LTE carriers.

 

The EARFCN is the center frequency of an LTE carrier that, along with the carrier bandwidth, identifies the carrier placement and occupied spectrum.

 

As Sprint is doing intraband contiguous/adjacent carrier aggregation -- 20 MHz TDD Band 41 carriers are lined up right next to one another with no gaps -- Band 41 EARFCNs are highly predictable in a given market by knowing the location of at least one carrier.

 

Say the ever popular EARFCN 40978 is the first carrier.

 

You add 198 (19.8 MHz) to it to get EARFCN 41176, which is the second Band 41 carrier.

Thus, it stands to reason if you add 198 to that EARFCN, you will get the third Band 41 carrier so 41176 + 198 = 41374, the EARFCN for the third Band 41 carrier.

 

Or, in some other markets, 41078 is the first Band 41 carrier. In this case, it goes like this: 41078 + 198 = 41276 + 198 = 41474

 

Alternatively, say a market has EARFCNs 40056 and 40254. Adding 198 would bring us to EARFCN 40452, but that is not possible due to the BRS/EBS 2500-2600 MHz band plan -- there are spectrum gaps around 2570 MHz and 2610 MHz that Sprint cannot utilize. See the band plan:

 

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Thus, in the case of EARFCNs 40056 and 40254, not addition, but use subtraction: 40056 - 198 = 39858, which would be the third Band 41 carrier.

 

The GCI is the unique cell sector identifier of a LTE carrier.

 

Generally speaking, Sprint's GCI patterns are standardized market by market and network wide, making for an easy method to identify each LTE carrier within a given band. In the case of Band 41, GCIs ending in 00/01/02 (Samsung) or x1/x2/x3 (ALU/NSN) indicate a connection to the original and first Band 41 carrier. GCIs ending in 03/04/05 (STA) or x9/xA/xB (ALU/NSN) denote the second Band 41 carrier.

 

It stands to reason that -- if this second carrier pattern were to continue to the third Band 41 carrier in Samsung markets -- we would expect to see GCIs possibly ending in 06/07/08. Long story short, this theory is supported by evidence. See below SignalCheck Pro logs and numerous in app screenshots:

 

This log is from my Nexus 5x. I traveled for a hour around Sacramento, searching for the third Band 41 carrier. Note the GCI endings for the Sprint Band 41 entries:

 

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The following is from site member bmoses in Des Moines. Note the 07 GCI ending and EARFCN:

 

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Below is from a S4GRU member in the Colorado market:

 

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One more from the Cincinnati, Ohio Market:

 

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The following is from yours truly in Sacramento:

 

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And these below are from Fremont, CA, near San Jose:

 

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See those EARFCNs and GCI endings? Look at the calculations from the top of this PSA. Everything is as we would have predicted for a third carrier.

 

With the end of the WiMAX injunction and the decomissioning of the last active Clearwire WiMAX markets that held up huge swaths of leased EBS and licensed BRS spectrum, Sprint finally has the capability to show off its deep spectrum pockets in numerous markets. This has been long awaited and should definitely give a huge boost to Sprint data speeds in numerous markets where spectrum for additional Band 41 carriers now is available. Of course, there still is the issue of actually connecting to and using this third Band 41 carrier.

 

From firsthand reports and personal use, this third Band 41 carrier is not currently carrier aggregation enabled. Thus, 2x/3x CA devices may not connect to it to use data right now. By default, these devices will have CA enabled, causing them to utilize only the first and second carriers that they can aggregate. For the time being, in order to reliably connect to this third carrier, a non CA triband device or a 2x/3x CA setting disabled triband device may be required. Regardless, this appears to be just a minor issue from the initial rollouts that should be resolved soon.

 

Source: S4GRU member reports

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i assume that once CA is enabled for this 3rd carrier since CA has to be adjacent 2xCA devices will see CA between the 1st and 2nd carriers or the 2nd and 3rd carriers but not the 1st and 3rd carriers?

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I wonder if Sprint phones in 2017 for the engineering menus will be updated to state "Primary Serving Cell", "Secondary Serving Cell", and "Tertiary Serving Cell"

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I wonder if Sprint phones in 2017 for the engineering menus will be updated to state "Primary Serving Cell", "Secondary Serving Cell", and "Tertiary Serving Cell"

 

The "Tertiary Serving Cell"?  I am looking forward to the "Triassic Serving Cell," not to mention the "Jurassic Serving Cell."  Those raptors can build intelligent networks.

 

:P

 

AJ

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Anyone have any idea if Clear Samsung equipmemt can broadcast the 3rd carrier while at the same time still do CA 2x?

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i assume that once CA is enabled for this 3rd carrier since CA has to be adjacent 2xCA devices will see CA between the 1st and 2nd carriers or the 2nd and 3rd carriers but not the 1st and 3rd carriers?

 

That is correct. The aggregated carriers must be contiguous.

 

I wonder if Sprint phones in 2017 for the engineering menus will be updated to state "Primary Serving Cell", "Secondary Serving Cell", and "Tertiary Serving Cell"

 

Interestingly enough they're all just called SCC's. In the Galaxy S7 engineering menu it's listed as PCC and then SCC1. We assume the SCC2 will show up when 3 carrier aggregation software update is pushed to the eNB's and enabled. 

 

Anyone have any idea if Clear Samsung equipmemt can broadcast the 3rd carrier while at the same time still do CA 2x?

 

Not capable. Tops out at 2xCA.

 

Only eNB equipment that can do 3xCA right now is the 8T8R equipment. 

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Not capable. Tops out at 2xCA.

 

Only eNB equipment that can do 3xCA right now is the 8T8R equipment.

 

I know it cannot do 3xCA what I meant was only broadcast that third carrier for capacity and still do 2xCA.

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I know it cannot do 3xCA what I meant was only broadcast that third carrier for capacity and still do 2xCA.

 

No. It's limited to 2 carriers per port / 40 MHz max LTE spectrum in current configuration. 

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This puts them up to par with the big two in terms of deployed spectrum. AT&T typically has 30 MHz B2, 20/10 MHz B12/17, and 10/20 MHz B4, not to mention 20 MHz WCS. This adds up to 90/70 MHz of deployed spectrum in each market. Verizon typically has 40 MHz B4, 20 MHz B13, and 20/10 MHz B2. That's 90/80 MHz of spectrum. With this, Sprint has 60 MHz B41, 10 MHz B26 and 10/20 MHz B25. That's 90/80 MHz of spectrum! With their marketshare and the same amount of spectrum, it's only a matter of time before they start winning speed awards. Now's the time to densify. We won't talk about T-Mobile... 60 MHz of spectrum at most.

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I know it cannot do 3xCA what I meant was only broadcast that third carrier for capacity and still do 2xCA.

Clear sites will need to be swapped to do the 3rd Carrier. which I believe will happen at some point.

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The latest SignalCheck Pro update includes Sprint third carrier indicators (B41³) as seen above.

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I got my taste of the third carrier in Hayward, CA today. Not bad but the speeds are not much improved yet. I hope Sprint gets backhaul upgraded soon.

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I got my taste of the third carrier in Hayward, CA today. Not bad but the speeds are not much improved yet. I hope Sprint gets backhaul upgraded soon.

Sprint is not doing new carriers without upgraded backhaul. Either your signal was not good, or they are tuning the site.

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Would resetting carrier services help with obtaining the new carrier or is that not needed?

 

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