T-Mobile CFO makes case for U.S. consolidation, Sprint deal

[bigsnake49]

Didn't say WCDMA isn't spread spectrum.  I just said its signaling doesn't work with a negative SNR.  LTE, by the way, with its multiple subcarrier approach over a wide frequency range, does qualify as a spread spectrum technology.  It isn't a frequency-hopping spread spectrum, but it is a wideband spread spectrum signal.

 

Inter cell interference coordination improves performance where cells overlap, not where cell sites are too far apart.  Your post didn't tell me anything I didn't know, and trust me, I would have considered it or even wrote it if it mattered.  Unfortunately, it doesn't matter at all in rural cell's edge coverage.  This is all great and quite necessary in an urban cell situation, in which case one cell might be overlapped by 10 others or more, in varying degrees and in varying locations.  This does no good at all in widely spaced environments.  On rural PCS site spacing, VoLTE simply will not work well because those sites were spaced for a technology that was more robust in the case of fade and weak signal.

 

Why don't you do this...  Take a compass or circle template and draw a few circles, much as a cellular network would be laid out, trying to cover as much as possible of your paper with as little overlap as possible.  Remember, your anti-interference techniques are great and all, but each and every one reduces capacity, so it's best to marginalize their use whenever possible.  Use red ink.  This is your CDMA2000 coverage.

 

Now, dial your compass down about 5-6% and make new circles using green ink, using all the same center points.  This is your effective LTE coverage.  Even though the signals on both technologies extend beyond the circles we have drawn, the circles visualize the usable range in which there will still be sufficient signal for your phone's radio to operate properly.  Look at all the holes!  "Hole"y s**t, there are a lot of dead zones!  Now, it should be noted that this only takes open air signal losses into account.  In a wooded area, or with building obstacles, this problem becomes even more serious..

 

Plain and simple, LTE needs more signal to operate at all, and where that signal isn't there at that level, your phone won't work.  Shifting power within a signal won't work to fix this.

 

Incidentally, I agree with your last paragraph and will add something to it.  Pushing LTE technologies so far in order to service edge of cell users will absolutely destroy performance closer to the center of the cell.

 

Didn't say WCDMA isn't spread spectrum.  I just said its signaling doesn't work with a negative SNR.  LTE, by the way, with its multiple subcarrier approach over a wide frequency range, does qualify as a spread spectrum technology.  It isn't a frequency-hopping spread spectrum, but it is a wideband spread spectrum signal.

 

Inter cell interference coordination improves performance where cells overlap, not where cell sites are too far apart.  Your post didn't tell me anything I didn't know, and trust me, I would have considered it or even wrote it if it mattered.  Unfortunately, it doesn't matter at all in rural cell's edge coverage.  This is all great and quite necessary in an urban cell situation, in which case one cell might be overlapped by 10 others or more, in varying degrees and in varying locations.  This does no good at all in widely spaced environments.  On rural PCS site spacing, VoLTE simply will not work well because those sites were spaced for a technology that was more robust in the case of fade and weak signal.

 

Why don't you do this...  Take a compass or circle template and draw a few circles, much as a cellular network would be laid out, trying to cover as much as possible of your paper with as little overlap as possible.  Remember, your anti-interference techniques are great and all, but each and every one reduces capacity, so it's best to marginalize their use whenever possible.  Use red ink.  This is your CDMA2000 coverage.

 

Now, dial your compass down about 5-6% and make new circles using green ink, using all the same center points.  This is your effective LTE coverage.  Even though the signals on both technologies extend beyond the circles we have drawn, the circles visualize the usable range in which there will still be sufficient signal for your phone's radio to operate properly.  Look at all the holes!  "Hole"y s**t, there are a lot of dead zones!  Now, it should be noted that this only takes open air signal losses into account.  In a wooded area, or with building obstacles, this problem becomes even more serious..

 

Plain and simple, LTE needs more signal to operate at all, and where that signal isn't there at that level, your phone won't work.  Shifting power within a signal won't work to fix this.

 

Incidentally, I agree with your last paragraph and will add something to it.  Pushing LTE technologies so far in order to service edge of cell users will absolutely destroy performance closer to the center of the cell.

 

If you want better signal increase the number of rural towers. Or apply to the 3GPP for an exception to increase the power level. I don't see either AT&T and Verizon complaining about it. They might have to built a few hundred more sites for rural areas, but so be it. The super-boomer sites won't reach forty miles they will reach 35. We had to go through the same things with the transition from AMPS to CDMA. Long live 5W bag phones!

[WiWavelength]

We had to go through the same things with the transition from AMPS to CDMA. Long live 5W bag phones!

 

Nice red herring.  No one has used bag phones for ages, so that is an irrelevant comparison.  Instead, compare handheld device AMPS coverage to handheld device CDMA1X coverage.  In terms of usable coverage area, CDMA1X wins.

 

Because AMPS control channels use such simple keying schemes, AMPS coverage may hold out longer, but it becomes completely unusable on voice channels because of inadequate SINR.  By its very nature, CDMA1X copes much better in such situations, providing equal or greater overall coverage.

 

AJ

[MrZorbatron]

If you want better signal increase the number of rural towers. Or apply to the 3GPP for an exception to increase the power level. I don't see either AT&T and Verizon complaining about it. They might have to built a few hundred more sites for rural areas, but so be it. The super-boomer sites won't reach forty miles they will reach 35. We had to go through the same things with the transition from AMPS to CDMA. Long live 5W bag phones!

3GPP's allowable power levels don't harm equipment petformance because current radios can't hit 3GPP's max numbers anyway, and you would need a very much narrower focus on a directional antenna (and therefore more radios/antennas and likely therefore narrower cells) to hit the FCC's ERP limits. Same goes for FCC limitations.

 

ATT and VZW don't complain because they have LTE in the 700 MHz band, which maintains a usable signal at a greater distance at a given power level. Couple that with the fact that both 700 and cellular 850 have band power limits that are higher than PCS, and you get the answer to why they do not care.

[bigsnake49]

Nice red herring.  No one has used bag phones for ages, so that is an irrelevant comparison.  Instead, compare handheld device AMPS coverage to handheld device CDMA1X coverage.  In terms of usable coverage area, CDMA1X wins.

 

Because AMPS control channels use such simple keying schemes, AMPS coverage may hold out longer, but it becomes completely unusable on voice channels because of inadequate SINR.  By its very nature, CDMA1X copes much better in such situations, providing equal or greater overall coverage.

 

AJ

 

Nice red herring.  No one has used bag phones for ages, so that is an irrelevant comparison.  Instead, compare handheld device AMPS coverage to handheld device CDMA1X coverage.  In terms of usable coverage area, CDMA1X wins.

 

Because AMPS control channels use such simple keying schemes, AMPS coverage may hold out longer, but it becomes completely unusable on voice channels because of inadequate SINR.  By its very nature, CDMA1X copes much better in such situations, providing equal or greater overall coverage.

 

AJ

 

So, put LTE 800MHz on very tower. Oh wait, that's exactly what Sprint is doing. If only because their 1900PCS network is not correctly spaced for 1900Mhz, at least in Florida.

Edited September 27, 2013 by bigsnake49

[bigsnake49]

3GPP's allowable power levels don't harm equipment petformance because current radios can't hit 3GPP's max numbers anyway, and you would need a very much narrower focus on a directional antenna (and therefore more radios/antennas and likely therefore narrower cells) to hit the FCC's ERP limits. Same goes for FCC limitations.

 

ATT and VZW don't complain because they have LTE in the 700 MHz band, which maintains a usable signal at a greater distance at a given power level. Couple that with the fact that both 700 and cellular 850 have band power limits that are higher than PCS, and you get the answer to why they do not care.

 

3GPP's allowable power levels don't harm equipment petformance because current radios can't hit 3GPP's max numbers anyway, and you would need a very much narrower focus on a directional antenna (and therefore more radios/antennas and likely therefore narrower cells) to hit the FCC's ERP limits. Same goes for FCC limitations.

 

ATT and VZW don't complain because they have LTE in the 700 MHz band, which maintains a usable signal at a greater distance at a given power level. Couple that with the fact that both 700 and cellular 850 have band power limits that are higher than PCS, and you get the answer to why they do not care.

Neither does Sprint which is putting LTE 800MHz on every 1900MHz spaced tower.

[MrZorbatron]

Neither does Sprint which is putting LTE 800MHz on every 1900MHz spaced tower.

Bull. Familiarize yourself with IBEZ.

 

Trust me, that will not be resolved before a nominal timeline would expect to see a widespread VoLTE transition. Unless Sprint wants to regain its hard-shed reputation for operaring an often substandard network, they will not make that mistake.

[Fraydog]

Take it from someone who has a CDMA carrier in a rural area, and that's Big Red. The edge of cell performance that Qualcomm says and the reality are two different things. What really happens on 1 bar of 1X? Usually a dropped call. Usually.

 

The fascination with keeping CDMA around past 2021, I'm kind of confused by. By then LTE should be able to handle edge of cells issues better than CDMA.

 

It's like Microsoft wanting to keep their legacy tech around, how is that working for them?

[MrZorbatron]

Take it from someone who has a CDMA carrier in a rural area, and that's Big Red. The edge of cell performance that Qualcomm says and the reality are two different things. What really happens on 1 bar of 1X? Usually a dropped call. Usually. The fascination with keeping CDMA around past 2021, I'm kind of confused by. By then LTE should be able to handle edge of cells issues better than CDMA. It's like Microsoft wanting to keep their legacy tech around, how is that working for them?

I would rather have some dropped calls than no service at all. I have a different experience with one bar service on CDMA. I have had many, in fact the vast majority of, such calls go perfectly well even for an hour or more. FYI, check the algorithm that Verizon phones use to calculate bars and it will really surprise you.

[IamMrFamous07]

I honestly think Sprint, SoftBank, Tmobile, and Dish are all working on something.

 

Mark my words lol

[bigsnake49]

I honestly think Sprint, SoftBank, Tmobile, and Dish are all working on something.

 

Mark my words lol

I'm with you!

[IamMrFamous07]

I'm with you!

Both sprint and tmobile cfos have publicly said they would like for their respective companies to merge and Sprint is still open to network sharing and gaining more spectrum.

[jefbal99]

I live on the edge of PCS coverage right now and I'm constantly dropping calls with my 1X singal being between -99 to -115.  I'll be outside, standing still, talking along then it magically drops.  I'll use my headset and place my on a window sill or on my railing to have no human antenna interference and it still will drop calls.

 

I was on hold for 20 minutes waiting for my kids DR office the other day, when I was 2nd in the waiting queue, my call dropped.

 

I can't wait for the other tower that can service me to get fired up (all the equipment is installed) because it has SMR radios.

 

Voice over LTE would be 100x worse as singal check disconnects and reconnects constantly.

[Terrell352]

I don't know where you figure you can get a 115dbm signal on 1x but on my EVO LTE and my girlfriend's GS3 Sprint's 1x band is completely gone at 105 dBm. Someone correct me if I'm wrong but on 1x goes to 105dbm, evdo is around 118 dBm and LTE is about 125 dBm

I live on the edge of PCS coverage right now and I'm constantly dropping calls with my 1X singal being between -99 to -115. I'll be outside, standing still, talking along then it magically drops. I'll use my headset and place my on a window sill or on my railing to have no human antenna interference and it still will drop calls.

 

I was on hold for 20 minutes waiting for my kids DR office the other day, when I was 2nd in the waiting queue, my call dropped.

 

I can't wait for the other tower that can service me to get fired up (all the equipment is installed) because it has SMR radios.

 

Voice over LTE would be 100x worse as singal check disconnects and reconnects constantly.

[MrZorbatron]

I don't know where you figure you can get a 115dbm signal on 1x but on my EVO LTE and my girlfriend's GS3 Sprint's 1x band is completely gone at 105 dBm. Someone correct me if I'm wrong but on 1x goes to 105dbm, evdo is around 118 dBm and LTE is about 125 dBm

In a low interference (rural) setting, CDMA of either type tends to remain usable, though not exactly stable, down to about -112 dBm signal levels.

[WiWavelength]

I don't know where you figure you can get a 115dbm signal on 1x but on my EVO LTE and my girlfriend's GS3 Sprint's 1x band is completely gone at 105 dBm. Someone correct me if I'm wrong but on 1x goes to 105dbm, evdo is around 118 dBm and LTE is about 125 dBm

 

For years, many CDMA2000 devices have seemingly utilized -105 dBm RSSI as the lowest displayed value for CDMA1X.  But that does not mean that -105 dBm RSSI is the lowest usable value.  Lower values may be usable, just not displayed.  Additionally, Ec/Io is more important signal metric.

 

AJ

[WiWavelength]

I live on the edge of PCS coverage right now and I'm constantly dropping calls with my 1X singal being between -99 to -115.  I'll be outside, standing still, talking along then it magically drops.  I'll use my headset and place my on a window sill or on my railing to have no human antenna interference and it still will drop calls.

 

That is almost certainly CDMA1X "cell breathing."  If you had soft handoff to another site, you would be probably be fine.  But you live on the edge of Sprint coverage, so you just made a poor choice of where to live.

 

 

AJ

[MrZorbatron]

Also, "human attenuation" such as is caused by hand position and the way you hold your head, becomes so much more of an issue in cases of very weak signal.  After all, a 3dB attenuation on a -106dBm signal is a lot bigger a problem than it is with a -98dBm signal.

[jefbal99]

In a low interference (rural) setting, CDMA of either type tends to remain usable, though not exactly stable, down to about -112 dBm signal levels.

Lowest I've had a successful call on the note 2 is -117

 

For years, many CDMA2000 devices have seemingly utilized -105 dBm RSSI as the lowest displayed value for CDMA1X. But that does not mean that -105 dBm RSSI is the lowest usable value. Lower values may be usable, just not displayed. Additionally, Ec/Io is more important signal metric.

 

AJ

I need to understand the rest of the metrics better.

 

That is almost certainly CDMA1X "cell breathing." If you had soft handoff to another site, you would be probably be fine. But you live on the edge of Sprint coverage, so you just made a poor choice of where to live.

 

 

AJ

The neighboring cells are not NV yet, my device stays locked onto this one site until I'm past the next site. As soon as the next site gets backhaul, I'll be good I think.

 

Also, "human attenuation" such as is caused by hand position and the way you hold your head, becomes so much more of an issue in cases of very weak signal. After all, a 3dB attenuation on a -106dBm signal is a lot bigger a problem than it is with a -98dBm signal.

Happens even when I prop my phone up with the flip cover and use my headset. Cell breathing has to be the cause.

 

Sent from my SPH-L900 using Tapatalk 4

 

 

[MrZorbatron]

Lowest I've had a successful call on the note 2 is -117

 

...

 

My GS3 fades badly if you push it below -112 or so.  I can text ok at -118. but the lowest voice call I've had work well was -116 way up north just a couple of weeks ago, and I had to very carefully adjust how I held the phone and the place where I was standing.  Side note...  Whoever laid out the cells in northern MI along US-23 is a moron.

[jefbal99]

My GS3 fades badly if you push it below -112 or so.  I can text ok at -118. but the lowest voice call I've had work well was -116 way up north just a couple of weeks ago, and I had to very carefully adjust how I held the phone and the place where I was standing.  Side note...  Whoever laid out the cells in northern MI along US-23 is a moron.

West Michigan was iPCS and they "designed" it for the absolute max of PCS considering bag phones and pull out antennas.

[bigsnake49]

West Michigan was iPCS and they "designed" it for the absolute max of PCS considering bag phones and pull out antennas.

Some of Florida is like that for Sprint. AT&T has Florida locked up, but man they really need 800MHz 1x and LTE like yesterday because the 1900MHz spacing ain't cutting it.

Edited October 1, 2013 by bigsnake49

[WiWavelength]

West Michigan was iPCS and they "designed" it for the absolute max of PCS considering bag phones and pull out antennas.

 

External, extensible antennas -- yes.  Bag phones -- no.

 

To my knowledge, Sprint never offered any bag phones.  PCS 1900 MHz devices were conceived as small, handhelds from the very beginning.  That was to be one of the advantages of PCS 1900 MHz over Cellular 850 MHz.

 

AJ

[jefbal99]

External, extensible antennas -- yes.  Bag phones -- no.

 

To my knowledge, Sprint never offered any bag phones.  PCS 1900 MHz devices were conceived as small, handhelds from the very beginning.  That was to be one of the advantages of PCS 1900 MHz over Cellular 850 MHz.

 

AJ

Thanks for the correction, I just made an assumption that Sprint started with bag phones.

[MrZorbatron]

Thanks for the correction, I just made an assumption that Sprint started with bag phones.

They did offer them as some of the first Sprint phones.  They didn't operate on PCS though, they weren't digital, and they weren't a nationwide service.  With the Sprint PCS service, however, it was always small handsets.

[MrZorbatron]

West Michigan was iPCS and they "designed" it for the absolute max of PCS considering bag phones and pull out antennas.

 

East MI was iPCS too in some areas.  Some of the east edge was built out by Sprint as part of a collocation project with Nextel.