LTE Plus / Enhanced LTE (was "Sprint Spark" - Official Name for the Tri-Band Network)

[RAvirani]

Where do you go in the Sprint Zone app to turn this on?

Yea...is this even an option on iPhone considering Apple doesn't allow access to most of the libraries I would imagine are necessary to have a feature like that?

[nexgencpu]

 

Here in NYC there is about 10-12dBm difference coming from same site.

 

But even with that 10-12dBm deficit, you notice how the user said B25 performed slightly worse than B41, and that's on a single carrier device (so expect 2x higher peak on those devices)

[Terrell352]

No that tower is about 1.2 miles down the road. There was actually a tower closer than that one so band 25 in there was actually between 98-112dbm because it was getting band 41 from the farther tower and band 25/26 from the closer one. At peak on band 41 at 124dbm I achieved 21 mbps showing that band 41 is very capable even with bad signal. SNR was good, often matching band 25 or exceeding.

That was taken inside a Walmart that sat next to a B41 tower. Do you think that would have been possible had the Walmart been 1 block away from the tower? Probably not. The fact that the Walmart was sitting next to the tower actually proves how much B41 can be affected by buildings. We've seen good network performance from 8t8r radios at the edge of cell, but the real question is how far has that edge of cell been pushed? I hope it's not to a couple more buildings next to the towers. Also, how low of a signal threshhold will our phones have to have on B41 until battrry life is diminished? If that user was sitting on an optimized B41 with beamforming on, then I'm not really optimistic about the reach of 8t8r. I'd like to be proven wrong, but I'm not going to hold my breath and expect to get B41 where I currently get a decent B25 in the future.

[S4GRU]

The big thing Sprint is looking to do to get B41 coverage nearly equal to existing B25 is a combination of increasing power Tx levels from B41 sites and returning Rx coming back on B25. A split downlink+uplink CA scenario. Similar to what ATT is doing with their B29, but for different reasons.

 

In this exercise, Sprint turns up B41 broadcast signals really high, to the point it covers the existing B25 coverage from the same site. This is easily doable in urban and suburban areas. And will even work for most rural sites, except those with mega spacing, like 8-10 miles. It won't reach that far, except possible outdoors LOS.

 

The reason why they can't do that now is when they turn up power levels too far, the signal travels much farther beyond then the device's ability to get back to the tower using B41. But Sprint is working on a Carrier Aggregation where it uses B41 downlink and returns back on B25 for uplink. This would allow a great expansion of B41 coverage.

 

This would take B41 over 98% of B25's footprint nationwide. And when you consider that Sprint is planning on a much further densification of B41, this will eventually make B41 nearly ubiquitous. The B41 experience will just get better and better and better.

 

The one place where it won't help much is those extremely spread apart very rural sites. Those are designed for B26 anyway. But even still, when you have two sites 16 miles apart, while outside, you would only have 2-3 miles between sites where you fall off B41+B25. So what that you have to use B26 for a few miles of really rural areas. You wouldn't even notice it while driving.

 

The only people who notice that they have B26 only, are the few people who would live in these rural areas between sites that are out of reach of B41+B25. But since the site they are connected to would then be covered with B41+B25, which carries most of the traffic, B26 only areas should perform pretty well. Like 10-20Mbps. And you're more likely to get B26 in a rural area to get near peak speeds than anywhere else (37.5Mbps).

 

Using Nexus 6 on Tapatalk

[WiWavelength]

The big thing Sprint is looking to do to get B41 coverage nearly equal to existing B25 is a combination of increasing power Tx levels from B41 sites and returning Rx coming back on B25.

 

If Sprint gets the band 25 + band 41 CA combo standardized, it will not be purely band 41 on the downlink.  Band 25 will be the PCC, supplying both uplink and downlink, and band 41 will be the SCC, aggregating supplemental downlink.  If band 25 supplied only the uplink, that would orphan its downlink, making that spectrum useless.

 

AJ

[S4GRU]

If Sprint gets the band 25 + band 41 CA combo standardized, it will not be purely band 41 on the downlink. Band 25 will be the PCC, supplying both uplink and downlink, and band 41 will be the SCC, aggregating supplemental downlink. If band 25 supplied only the uplink, that would orphan its downlink, making that spectrum useless.

 

AJ

I don't think it would make it useless. Currently B 25 uplink is quite under utilized. I think it could carry B 41 additional uplink traffic just fine, in the areas outside conventional b41 coverage.

 

Using Tapatalk on Nexus 6

[S4GRU]

It doesn't have to be either, or. AT&T is using other bands through carrier aggregation for its B 29. But it doesn't ruin the uplink on the other band. It is still able to be used without CA on the uplink.

 

Using Tapatalk on Nexus 6

[WiWavelength]

I don't think it would make it useless. Currently B 25 uplink is quite under utilized. I think it could carry B 41 additional uplink traffic just fine, in the areas outside conventional b41 coverage.

 

No, I think you are missing what I am saying.  Using only the band 25 uplink would orphan the band 25 downlink, which would sit there unused.

 

It doesn't have to be either, or. AT&T is using other bands through carrier aggregation for its B 29. But it doesn't ruin the uplink on the other band. It is still able to be used without CA on the uplink.

 

What AT&T is or will be doing with, for example, band 2 + band 29 CA is almost exactly what Sprint would be doing with band 25 + band 41 CA.  Band 2 is the PCC, providing both uplink and downlink, while band 29 is the SCC, providing supplemental downlink.  Swap band 2 for band 25 and band 29 for band 41, and you have a similar configuration for Sprint.

 

The important point is that network signaling, which requires both uplink and downlink, goes over only the PCC.  I doubt that 3GPP will ever standardize splitting that network signaling between an uplink on the PCC and a downlink on the SCC or vice versa.

 

AJ

[nick]

The big thing Sprint is looking to do to get B41 coverage nearly equal to existing B25 is a combination of increasing power Tx levels from B41 sites and returning Rx coming back on B25. A split downlink+uplink CA scenario. Similar to what ATT is doing with their B29, but for different reasons.

 

In this exercise, Sprint turns up B41 broadcast signals really high, to the point it covers the existing B25 coverage from the same site. This is easily doable in urban and suburban areas. And will even work for most rural sites, except those with mega spacing, like 8-10 miles. It won't reach that far, except possible outdoors LOS.

 

The reason why they can't do that now is when they turn up power levels too far, the signal travels much farther beyond then the device's ability to get back to the tower using B41. But Sprint is working on a Carrier Aggregation where it uses B41 downlink and returns back on B25 for uplink. This would allow a great expansion of B41 coverage.

 

This would take B41 over 98% of B25's footprint nationwide. And when you consider that Sprint is planning on a much further densification of B41, this will eventually make B41 nearly ubiquitous. The B41 experience will just get better and better and better.

 

The one place where it won't help much is those extremely spread apart very rural sites. Those are designed for B26 anyway. But even still, when you have two sites 16 miles apart, while outside, you would only have 2-3 miles between sites where you fall off B41+B25. So what that you have to use B26 for a few miles of really rural areas. You wouldn't even notice it while driving.

 

The only people who notice that they have B26 only, are the few people who would live in these rural areas between sites that are out of reach of B41+B25. But since the site they are connected to would then be covered with B41+B25, which carries most of the traffic, B26 only areas should perform pretty well. Like 10-20Mbps. And you're more likely to get B26 in a rural area to get near peak speeds than anywhere else (37.5Mbps).

 

Using Nexus 6 on Tapatalk

this would be a game changer! thanks for the explanation, how far down the road before we start seeing this? 1-2 years or 4-5 years

[S4GRU]

No, I think you are missing what I am saying. Using only the band 25 uplink would orphan the band 25 downlink, which would sit there unused.

 

 

What AT&T is or will be doing with, for example, band 2 + band 29 CA is almost exactly what Sprint would be doing with band 25 + band 41 CA. Band 2 is the PCC, providing both uplink and downlink, while band 29 is the SCC, providing supplemental downlink. Swap band 2 for band 25 and band 29 for band 41, and you have a similar configuration for Sprint.

 

The important point is that network signaling, which requires both uplink and downlink, goes over only the PCC. I doubt that 3GPP will ever standardize splitting that network signaling between an uplink on the PCC and a downlink on the SCC or vice versa.

 

AJ

In Sprint's instance, B25 capable devices without CA would still use B25 uplink/downlink. Also, B41+B25 CA devices can still use B25 uplink/downlink only when not in range of B41 (which can still happen).

 

This is what happens on ATT. The downlink/uplink is still working on B2 when paired with B29. But only on a B2 capable device and no B29 present. Maybe you're just concerned about under utilization?

 

Using Tapatalk on Nexus 6

[S4GRU]

No, I think you are missing what I am saying. Using only the band 25 uplink would orphan the band 25 downlink, which would sit there unused.

 

 

What AT&T is or will be doing with, for example, band 2 + band 29 CA is almost exactly what Sprint would be doing with band 25 + band 41 CA. Band 2 is the PCC, providing both uplink and downlink, while band 29 is the SCC, providing supplemental downlink. Swap band 2 for band 25 and band 29 for band 41, and you have a similar configuration for Sprint.

 

The important point is that network signaling, which requires both uplink and downlink, goes over only the PCC. I doubt that 3GPP will ever standardize splitting that network signaling between an uplink on the PCC and a downlink on the SCC or vice versa.

 

AJ

Also, the way it was described to me by a Samsung engineer was that Sprint was working to pair only B41 downlink with B25 uplink. Bypassing a B41+B25 downlink combo altogether. They had already worked out technically how it would work and were going to lab trial it soon. This is a new type of CA that had not been done before, and would likely not even need a new LTE release to achieve. We will have to see what comes out of the Lenexa labs.

 

But even if that does not work out, it's not the end of the world to use a conventional CA method.

 

Using Tapatalk on Nexus 6

[S4GRU]

this would be a game changer! thanks for the explanation, how far down the road before we start seeing this? 1-2 years or 4-5 years

I think the fastest reasonable release would be another year out. But more likely 2-3 years.

 

Using Tapatalk on Nexus 6

[Yuhfhrh]

If Sprint does go with B25+B41, it would be nice to see them adjust the TDD ratio even further for more downlink capacity.

[utiz4321]

I think the fastest reasonable release would be another year out. But more likely 2-3 years.

 

Using Tapatalk on Nexus 6

I forgot where I heard this (it was probably here) but isn't there a chance that if they use CA between b41 and b25 then they can only use the b25 for uplink wasting the b41 uplink. That seems like a limitation that would make for some very poor uplink speeds.

[S4GRU]

I forgot where I heard this (it was probably here) but isn't there a chance that if they use CA between b41 and b25 then they can only use the b25 for uplink wasting the b41 uplink. That seems like a limitation that would make for some very poor uplink speeds.

The B41 uplink will still be usable for devices on B41 only and not on a CA connection.

 

Using Tapatalk on Nexus 6

[WiWavelength]

In Sprint's instance, B25 capable devices without CA would still use B25 uplink/downlink. Also, B41+B25 CA devices can still use B25 uplink/downlink only when not in range of B41 (which can still happen).

 

This is what happens on ATT. The downlink/uplink is still working on B2 when paired with B29. But only on a B2 capable device and no B29 present. Maybe you're just concerned about under utilization?

Also, the way it was described to me by a Samsung engineer was that Sprint was working to pair only B41 downlink with B25 uplink. Bypassing a B41+B25 downlink combo altogether. They had already worked out technically how it would work and were going to lab trial it soon. This is a new type of CA that had not been done before, and would likely not even need a new LTE release to achieve. We will have to see what comes out of the Lenexa labs.

 

But even if that does not work out, it's not the end of the world to use a conventional CA method.

 

I may have to address this in multiple posts -- because I could use a nap.  But I will get started here.

 

I have seen the band 25 uplink + band 41 downlink CA possibility mentioned in several articles.  Repetition does not equal fact, however.  Certainly, I could be wrong, but I think that description is just the engineers or spokespeople dumbing down the band 25 + band 41 CA for the laypeople.  Even so, FDD + TDD would represent a "new type of CA," thus satisfying that requirement.

 

In the short term, orphaning the band 25 downlink might not be a big deal.  As Robert says, non CA devices would continue to use it.  But in the long run, not including the band 25 downlink as the PCC in CA would make no sense.

 

Early on, if this CA combo were to be standardized, only cutting edge flagship handsets would benefit.  But the trickle down effect would not take long.  Look at the low end, mid range, and prepaid handsets now compared to two years ago -- tri band is standard.  Band 41 2x/3x CA is next.  And this experimental CA would not take that long to permeate through the device lineup.

 

From Sprint's PCS A-F block spectrum holdings, we know that it eventually will have 10-15 MHz FDD band 25 second carriers across most markets -- after CDMA2000 thinning or shutdown.  More or less wasting that 10-15 MHz FDD downlink would be a shame.  Sprint could not sell that half of its paired band 25 spectrum, while fewer and fewer devices would actually use the spectrum -- because they would be purely on band 25 uplink and band 41 downlink.

 

So, no, as some have described the band 25 uplink + band 41 downlink CA possibility, I do not think that will ever happen.  It needs to be band 25 PCC uplink/downlink + band 41 SCC downlink.  And with the wealth of BRS/EBS spectrum that Sprint has in most markets, it could even get a new supplemental downlink CA band standardized, ditching the TDD operation on at least one formerly band 41 carrier.  In that way, the supplemental downlink CA would be exactly like that of AT&Ts band 29.

 

Now, I have earned my nap...

 

AJ

[S4GRU]

I may have to address this in multiple posts -- because I could use a nap. But I will get started here.

 

I have seen the band 25 uplink + band 41 downlink CA possibility mentioned in several articles. Repetition does not equal fact, however. Certainly, I could be wrong, but I think that description is just the engineers or spokespeople dumbing down the band 25 + band 41 CA for the laypeople. Even so, FDD + TDD would represent a "new type of CA," thus satisfying that requirement.

 

In the short term, orphaning the band 25 downlink might not be a big deal. As Robert says, non CA devices would continue to use it. But in the long run, not including the band 25 downlink as the PCC in CA would make no sense.

 

Early on, if this CA combo were to be standardized, only cutting edge flagship handsets would benefit. But the trickle down effect would not take long. Look at the low end, mid range, and prepaid handsets now compared to two years ago -- tri band is standard. Band 41 2x/3x CA is next. And this experimental CA would not take that long to permeate through the device lineup.

 

From Sprint's PCS A-F block spectrum holdings, we know that it eventually will have 10-15 MHz FDD band 25 second carriers across most markets -- after CDMA2000 thinning or shutdown. More or less wasting that 10-15 MHz FDD downlink would be a shame. Sprint could not sell that half of its paired band 25 spectrum, while fewer and fewer devices would actually use the spectrum -- because they would be purely on band 25 uplink and band 41 downlink.

 

So, no, as some have described the band 25 uplink + band 41 downlink CA possibility, I do not think that will ever happen. It needs to be band 25 PCC uplink/downlink + band 41 SCC downlink. And with the wealth of BRS/EBS spectrum that Sprint has in most markets, it could even get a new supplemental downlink CA band standardized, ditching the TDD operation on at least one formerly band 41 carrier. In that way, the supplemental downlink CA would be exactly like that of AT&Ts band 29.

 

Now, I have earned my nap...

 

AJ

And if the B25 downlink gets under utilized to the point that performance is really high, the network could shunt a user there for capacity. The device could still use B25 uplink/downlink conventionally. Especially in markets where Sprint is operating a B25 10x10.

 

Also, Sprint could offer a Cricket like service on one of it's budget brands that has limited performance for a lower price. That would work on B25 only. There's a lot of ways to skin the cat. But it would still be a few years before B25 gets under utilized.

 

Using Tapatalk on Nexus 6

[JonnygATL]

The fact that we are even able to discuss band 25 becoming under utilized due to the prevalence of a higher capacity band shows just how far Sprint has really come.

[RAvirani]

The fact that we are even able to discuss band 25 becoming under utilized due to the prevalence of a higher capacity band shows just how far Sprint has really come.

Remember the dark ages before lte XD

[WiWavelength]

And if the B25 downlink gets under utilized to the point that performance is really high, the network could shunt a user there for capacity. The device could still use B25 uplink/downlink conventionally. Especially in markets where Sprint is operating a B25 10x10.

 

Also, Sprint could offer a Cricket like service on one of it's budget brands that has limited performance for a lower price. That would work on B25 only. There's a lot of ways to skin the cat. But it would still be a few years before B25 gets under utilized.

 

Well, I stand by my assessment.  I highly doubt that Sprint will seek to standardize just a band 25 uplink + band 41 downlink.  That would not really even be true CA -- it would be like an entirely new 3GPP band with the uplink and downlink separated by 700 MHz, somewhat akin to AWS-1/3 with its 400 MHz duplex offset.

 

No, if Sprint goes down this path, I fully expect it will go with a PCC band 25 uplink/downlink + SCC band 41 downlink CA strategy.  Both PCC band 26 uplink/downlink + SCC band 41 CA and PCC band 26 uplink/downlink + SCC band 25 downlink CA should be standardized at that time, too.  The question in my mind, though, is whether Sprint will pursue the unconventional FDD + TDD CA -- or just use available BRS/EBS spectrum for 20 MHz supplemental downlink CA, no TDD in that combo.

 

AJ

[RAvirani]

Well, I stand by my assessment.  I highly doubt that Sprint will seek to standardize just a band 25 uplink + band 41 downlink.  That would not really even be true CA -- it would be like an entirely new 3GPP band with the uplink and downlink separated by 700 MHz, somewhat akin to AWS-1/3 with its 400 MHz duplex offset.

 

No, if Sprint goes down this path, I fully expect it will go with a PCC band 25 uplink/downlink + SCC band 41 downlink CA strategy.  Both PCC band 26 uplink/downlink + SCC band 41 CA and PCC band 26 uplink/downlink + SCC band 25 downlink CA should be standardized at that time, too.  The question in my mind, though, is whether Sprint will pursue the unconventional FDD + TDD CA -- or just use available BRS/EBS spectrum for 20 MHz supplemental downlink CA, no TDD in that combo.

 

AJ

I honestly think that sprint will end up aggregating 20mhz TDD-LTE bands in 2600 and stay away from FDD-TDD aggregation. I can see them doing stuff with 800 and 1900 aggregation though...

[Paynefanbro]

The fact that we are even able to discuss band 25 becoming under utilized due to the prevalence of a higher capacity band shows just how far Sprint has really come.

 

That's already the case in NYC in my experience. I'm either on Band 41 or Band 26. When by chance I am on Band 25, speeds are usually around 8-10Mbps.

[barkada]

We just saw a pullback on a couple of sites where Clearwire equipment was being upgraded to Sprint equipment. Rumor has it that there is a nationwide stoppage on all work on the Clearwire to Sprint evolution project. Does anyone have any additional details about this?

[bucdenny]

Is CA defined on the phone or the network sets CA? I have good signal at around -100 RSRP on B41 with CA and then dropping to B25. When back on B41, my S6 doesn't want to be on CA. It is load balancing between the two carriers. Speeds on single carrier B41 20-30Mbps and when on CA getting 50-80Mbps.

 

95% of B41 sites in San Diego already has the second carrier and CA. The problem is we dont see CA kick in right away.

 

Also I have found CA less often with -100 RSRP or worse. Is there a limitation on signal strength for CA?

[MacinJosh]

2 carriers of Band 41 LTE found in Henderson, NV today. Anyone in Vegas with a CA capable phone want to see if CA is enabled. Message me for location.

 

 

 

 

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