T-Mobile LTE & Network Discussion

[ericdabbs]

At least another 20Mhz in all markets? I think anything over 40Mhz(including G) is overkill in markets where Clearwire has 50-60Mhz of continuous spectrum. 1xAdvanced has the ability to be configured to provide 4x the capacity over the same area as current 1x,  I do not believe Sprint will need to add any more 1x carriers, especially with the 1x carrier on the 800Mhz. LTE will distribute the burden off the PCS spectrum onto the BRS and 800Mhz Spectrum. 10Mhz of SMR + 20Mhz of PCS + 40Mhz of BRS is a ton of capacity. Verizon is going to be stuck with 20Mhz of 700 and only another 20-40Mhz of AWS.  Tmobile does not currently have any options outside their AWS spectrum, if it were to get burdened. 

 

There is no evidence that the 1x Advanced carriers has been configured for 4x capacity at the NV tower side.  So even though at some point it can be configured for 4x capacity it will still be years from now before we see that happening.

 

Also the "4x capacity" is a culmination of the tower side and handset side 1x Advanced upgrades which so far only the smartphones beginning in 2012 contain the qualcomm chip that supports 1x Advanced.  There are still plenty of folks out there including myself that have yet to upgrade which are still on 1x CDMA 2000.  Sprint cannot afford to collapse all CDMA voice into a single CDMA carrier on 800 and 1900 just yet.  Also we have to keep in mind that multiple 3G EVDO carriers are eating up precious spectrum which cannot be taken down until LTE is well into completion.  I see Sprint only taking down all EVDO carriers only to free up spectrum when it plans to take down the entire 3G network all together 1x and EVDO which would signal VoLTE is prime time ready which will be many years from now.  We still have AT&T and Tmobile running 2G networks for gosh sakes.

 

The problem with Clearwire TD-LTE is that currently it is going to be deployed on a hotspot basis.  Clearwire still hasn't mentioned any plan of upgrading all 16,000+ sites to TD-LTE and also to major markets that were never deployed with Wimax.  We just don't know the full plan that Softbank/Sprint have for TD-LTE yet and I find it hard financially and feasibly to deploy TD-LTE nationwide.  Therefore I am not convinced and going to overestimate the impact of TD-LTE in terms of its offloading capacity in most areas I will be in. 

 

All I am saying is that if that if Sprint can get at least another 10-20 MHz of PCS spectrum they should.  There is nothing wrong with Tmobile focusing only on AWS spectrum.  The AWS spectrum band is growing rapidly with the AWS-3 (2155-2180 Mhz paired with 1755-1780 MHz) spectrum being auctioned sometime next year which is 50 MHz of fresh AWS spectrum. Tmobile and possibly Verizon are going to be the major players bidding on that spectrum.  Tmobile will be fine and they can always refarm their PCS spectrum into LTE.

[ChadBroChillz]

There is no evidence that the 1x Advanced carriers has been configured for 4x capacity at the NV tower side.  So even though at some point it can be configured for 4x capacity it will still be years from now before we see that happening.

 

Also the "4x capacity" is a culmination of the tower side and handset side 1x Advanced upgrades which so far only the smartphones beginning in 2012 contain the qualcomm chip that supports 1x Advanced.  There are still plenty of folks out there including myself that have yet to upgrade which are still on 1x CDMA 2000.  Sprint cannot afford to collapse all CDMA voice into a single CDMA carrier on 800 and 1900 just yet.  Also we have to keep in mind that multiple 3G EVDO carriers are eating up precious spectrum which cannot be taken down until LTE is well into completion.  I see Sprint only taking down all EVDO carriers only to free up spectrum when it plans to take down the entire 3G network all together 1x and EVDO which would signal VoLTE is prime time ready which will be many years from now.  We still have AT&T and Tmobile running 2G networks for gosh sakes.

 

The problem with Clearwire TD-LTE is that currently it is going to be deployed on a hotspot basis.  Clearwire still hasn't mentioned any plan of upgrading all 16,000+ sites to TD-LTE and also to major markets that were never deployed with Wimax.  We just don't know the full plan that Softbank/Sprint have for TD-LTE yet and I find it hard financially and feasibly to deploy TD-LTE nationwide.  Therefore I am not convinced and going to overestimate the impact of TD-LTE in terms of its offloading capacity in most areas I will be in. 

 

All I am saying is that if that if Sprint can get at least another 10-20 MHz of PCS spectrum they should.  There is nothing wrong with Tmobile focusing only on AWS spectrum.  The AWS spectrum band is growing rapidly with the AWS-3 (2155-2180 Mhz paired with 1755-1780 MHz) spectrum being auctioned sometime next year which is 50 MHz of fresh AWS spectrum. Tmobile and possibly Verizon are going to be the major players bidding on that spectrum.  Tmobile will be fine and they can always refarm their PCS spectrum into LTE.

 

 

I highly doubt Sprint has paid the billions necessary to deploy new 1xAdvanced channels cards for the 4x configuration to be years away. I would think that this would be the perfect time for them to make all the necessary upgrades, plus I believe their are capacity benefits that current 1x phones could take advantage of. 

 

I believe you misunderstood my argument, I was not making the argument to reduce 1x carriers. My argument was that Sprint would not need additional 1x carriers, because of the increased capacity benefits. Sprint does not need more EVDO carriers, because of the shift to LTE for data. My argument also assumed that Sprint would use 20Mhz for its 1x and EVDO carriers, which is why I only allocated 20Mhz of PCS spectrum for LTE.

 

You are correct, we do not know the full plan, but I highly doubt Softbank would push Sprint to absorbing Clearwire, if their plan was just to continue to use them for hotspots. Masayoshi Son has said they would not reveal their plans, but it is clear by his actions that they have more in mind than just hotspots, especially with the news that Sprint was looking into carrier aggregating two 20Mhz TD-LTE channels.  When I mention nationwide, I do not mean over their entire 3G network. I mean covering major cities, similar to Tmobile's current HSPA+ deployment. 

 

I have no problem with Sprint going after the PCS-H block, especially in my market, which does not have 40Mhz A-G and will not get the full benefits of LTE on 800Mhz. I just do not believe it is needed in markets that have 40Mhz A-G. 

[Rawvega]

Could tmobile get an iphone with LTE Band 12?

 

Unknown at this point. Apple won't make one for USCC, though obviously T-Mobile is a bigger customer than USCC.

 

http://www.fiercebroadbandwireless.com/story/us-cellular-spectrum-partner-bewails-absence-band-12-apples-iphone/2013-05-30

[bigsnake49]

I worry about 600MHz. There are a lot of technical problems with it.

 

I would much rather see T-Mobile buy the 700MHz Lower A block and use that, instead. It would be cheaper than the auction, and it would be far less of a headache than what 600MHz is shaping up to be.

 

I have long advocated for Sprint/Tmobile to start scooping 700Mhz lower A and bid for what is now channel 51 or whatever block it will be.

 

Non optimal antennas have always been with us. I mean if you have PCS A and G or H spectrum you will not have three antennas each tuned to each band. You will have an antenna tuned to the midband. Same thing with cellular and SMR. At least on the handset side.

[WiWavelength]

700 A has its own issues, namely interference with TV stations. That's why neither Verizon nor AT&T want it. And the fact that 700 A interference zones are primarily urban doesn't help TMo's case for that band in the least.

To the contrary, TMO is greatly helped as it doesn't need urban 700; it needs rural 700.

Guys, those DT channel 51 protection zones follow their stations' Grade A Contours, which can easily extend 60 miles outside of urban areas. In other words, they impede the most valuable rural areas, too.

 

AJ

[bigsnake49]

Guys, those DT channel 51 protection zones follow their stations' Grade A Contours, which can easily extend 60 miles outside of urban areas. In other words, they impede the most valuable rural areas, too.

 

AJ

That's why we has filters .

[WiWavelength]

That's why we has filters .

 

Filters are subject to the limitations of physics; thus, they are not perfect.  If they were, then LightSquared's plan would have worked.

 

AJ

[ChadBroChillz]

That's why we has filters .

 

Did this man sell you those filters?

[bigsnake49]

Filters are subject to the limitations of physics; thus, they are not perfect.  If they were, then LightSquared's plan would have worked.

 

AJ

 

USCC made 700Mhz band A work. Either they have no channel 51 anywhere in their footprint or they designed effective filters.

 

Lightsquared plan would work for new devices. It would not work for already existing devices.

[WiWavelength]

USCC made 700Mhz band A work. Either they have no channel 51 anywhere in their footprint or they designed effective filters.

Maybe, but I have yet to see any evidence that USCC is operating in the Lower 700 MHz A block specifically inside any of the DT channel 51 contours.

 

Lightsquared plan would work for new devices. It would not work for already existing devices.

Those "new" GPS devices would have been very large and expensive to accommodate very sharp bandpass filters. Or, more likely, they would have remained small and inexpensive but had significantly lower GPS signal sensitivity. Again, filters are not perfect.

 

AJ

[bigsnake49]

Maybe, but I have yet to see any evidence that USCC is operating in the Lower 700 MHz A block specifically inside any of the DT channel 51 contours.

 

Those "new" GPS devices would have been very large and expensive to accommodate very sharp bandpass filters. Or, more likely, they would have remained small and inexpensive but had significantly lower GPS signal sensitivity. Again, filters are not perfect.

 

AJ

You know that nowadays those filters are done on a chip level. You no longer need to have these huge capacitors and coils like when I went to school.

[WiWavelength]

Does it make sense for TMUS to upgrade to HSPA+84 and higher?

 

No.

 

First, DC-HSPA+ 84 requires 20 MHz of spectrum, which is what T-Mobile currently requires for DC-HSPA+ 42.  That precludes DC-HSPA+ 84 in markets where T-Mobile currently has only enough spectrum for HSPA+ 21.  And those market numbers will grow, as T-Mobile shifts more and more spectrum to LTE.

 

Second, DC-HSPA+ 84 requires 2x2 MIMO, and MIMO does not seem to play well with existing W-CDMA.  So, as far as I know, few W-CDMA operators have implemented MIMO.  That is better left to LTE.

 

AJ

[WiWavelength]

You know that nowadays those filters are done on a chip level. You no longer need to have these huge capacitors and coils like when I went to school.

 

That is digital filtering.  It works well for digital audio.  But modulated RF is analog.

 

AJ

[bigsnake49]

That is digital filtering.  It works well for digital audio.  But modulated RF is analog.

 

AJ

Still in silicon.

[bigsnake49]

That is digital filtering.  It works well for digital audio.  But modulated RF is analog.

 

AJ

Have you heard of switch filter modules? There was a a lot of these companies that used to make switch filter modules for phones along with duplexer switches etc. The giant sucking sound you just heard is their business getting sucked out of them by the Qualcomm RF360 solution.

[Conan Kudo]

Have you heard of switch filter modules? There was a a lot of these companies that used to make switch filter modules for phones along with duplexer switches etc. The giant sucking sound you just heard is their business getting sucked out of them by the Qualcomm RF360 solution.

Filters/Duplexers are not included in the RF360 solution. The integrated PA switch still requires external filters/duplexers. Most manufacturers use filters/duplexers from Murata. Look them up.

[bigsnake49]

Filters/Duplexers are not included in the RF360 solution.

I guess I should have look at the spec sheet. Oops.... Don't worry, it will. Give them time.

[maximus1987/lou99]

 

700 A has its own issues, namely interference with TV stations. That's why neither Verizon nor AT&T want it. And the fact that 700 A interference zones are primarily urban doesn't help TMo's case for that band in the least.

To the contrary, TMO is greatly helped as it doesn't need urban 700; it needs rural 700.

Guys, those DT channel 51 protection zones follow their stations' Grade A Contours, which can easily extend 60 miles outside of urban areas. In other words, they impede the most valuable rural areas, too.

 

 

AJ

Could someone buy all the channel 51 stations, shut them down and use them as guard bands?

 

Also, how did everyone miss this ch 51 issue? If the FCC knew about it, why even auction A block?

 

Is the FCC doing something to deal with this issue?

[WiWavelength]

Still in silicon.

 

Naw, not really.  As info from LightSquared opponents and LightSquared "savior" Javad showed, we are still talking some discrete components.

 

AJ

[Conan Kudo]

Could someone buy all the channel 51 stations, shut them down and use them as guard bands?

 

Also, how did everyone miss this ch 51 issue? If the FCC knew about it, why even auction A block?

 

Is the FCC doing something about this issue?

In theory, someone could buy the Ch51 stations and shut them down. There are sufficiently few of them that it is possible. However, it would make the FCC very mad. They don't like stuff like that.

 

The FCC was aware of the issue from the beginning. Lower 700 A block was auctioned at a lower cost (my house costs more than the A block license for my market!) than the others.

 

The FCC dawdled a bit on dealing with it, before finally freezing applications for Ch 51 in August 2011. They haven't done anything since.

[maximus1987/lou99]

What about interoperability? Does anyone know even how they're leaning?

[bigsnake49]

Naw, not really.  As info from LightSquared opponents and LightSquared "savior" Javad showed, we are still talking some discrete components.

 

AJ

Maybe at the basestation. The power envelopes and slope requirements are much smaller at the handsets. Javad was talking about 12db/MHz fliters. That's a pretty darn sharp filter.

Edited June 5, 2013 by bigsnake49

[WiWavelength]

Maybe at the basestation. The power envelopes and slope requirements are much smaller at the handsets.

 

Not in this case.  It is the uplink from the handsets that causes much of the DT channel 51 issue because it is the Lower 700 MHz A block uplink that is adjacent to DT channel 51.  Handsets go everywhere, and just as the uplink of an AWS-4 handset could interfere with reception of the PCS G and AWS-2/PCS H downlinks, the uplink of a Lower 700 MHz A block device could interfere with the reception of an OTA receiver tuned to DT channel 51.

 

AJ

[bigsnake49]

Not in this case.  It is the uplink from the handsets that causes much of the DT channel 51 issue because it is the Lower 700 MHz A block uplink that is adjacent to DT channel 51.  Handsets go everywhere, and just as the uplink of an AWS-4 handset could interfere with reception of the PCS G and AWS-2/PCS H downlinks, the uplink of a Lower 700 MHz A block device could interfere with the reception of an OTA receiver tuned to DT channel 51.

 

AJ

 Usually those antennas are outside on the roof. Not too many of them on the inside. The only time you would have an interference problem is at the edge of Channel 51 coverage areas. I mean channel 51 transmitters are at 100,000 watts or more and we are worried about the less than .5 watts erp of a phone. You will have to hold the phone extremely close to that antenna before it interferes. 

[WiWavelength]

 Usually those antennas are outside on the roof. Not too many of them on the inside. The only time you would have an interference problem is at the edge of Channel 51 coverage areas. I mean channel 51 transmitters are at 100,000 watts or more and we are worried about the less than .5 watts erp of a phone. You will have to hold the phone extremely close to that antenna before it interferes. 

 

Your math is off.  Even with a DT channel 51 transmitter operating at 100,000 W (80 dBm), free space path loss alone at only 25 km distance is 117 dB.  So, that 80 dBm signal has already diminished to -37 dBm, at best.  Meanwhile, nearby Lower 700 MHz A block mobiles could be transmitting at 23 dBm in the adjacent channel.  That presents a 60 dB difference and a big filtering problem.

 

Plus, you cannot assume where the DT antennas are located.  At only 25 km distance and still likely inside the metro area, plenty of people use indoor antennas.

 

Regardless, DT channel 51 was there first and is entitled to significant protection until it is retired.  That is the key fact.

 

AJ