WSJ: Sprint looking at T-Mobile purchase

[WiWavelength]

I'd like to know where you got that idea, because it seemed to me that LTE has more tolerance of a weaker signal than CDMA 1X does. Also, the repeated FUD you push about VoLTE. VoLTE has some problems related to software implementation details, but I don't ever recall there being coverage issues. Have you ever used VoLTE in the real world to see how it works? Remember, it doesn't work the same way as Skype or other VoIP packages do.

 

Oh come on, Neal.  You know that I have the upper hand in matters of RF knowledge.  And this one is relatively simple.  It comes down to differences in the physical layers between the two airlinks.

 

For both CDMA1X and LTE, the base modulation scheme is QPSK, so that puts them roughly at parity.  However, CDMA1X is spreading low bit rate voice data across an entire 1.25 MHz broadband carrier, while VoLTE is putting low bit rate voice data in 15 kHz narrowband subcarriers.  CDMA1X benefits from spreading gain; LTE does not.  Now, that spreading gain is not always efficient, since it trades off high data rates for spreading gain, but it allows CDMA1X to operate at negative SINR.  LTE, on the other hand, effectively requires positive SINR.

 

This is fundamental communications theory, Neal.  Do you need a refresher on Shannon-Hartley?

 

http://en.wikipedia.org/wiki/Shannon–Hartley_theorem

 

Moreover, empirical research bears this out.  Ask hundreds of experienced wireless users here at S4GRU, "Which airlink falters first -- CDMA1X or LTE?"  That is practically a rhetorical question.  The answer is almost unequivocally "LTE."  And I can demonstrate this time after time by hopping in my car and intentionally driving away from Sprint native coverage. 

 

Yes, in the end, VoLTE provides some QoS protections.  But those protections are still limited by the physical layer of the LTE airlink itself.  LTE is very efficient, approaching the Shannon bound, but it does so by trading off robustness for high data rates.

 

AJ

[jamisonshaw125]

This is a website devoted to sprint networks. One would expect those who have sprint would want to see the sprint network improve and flourish. What is it that you want to see GinaDee?

 

Jim, Sent from my Photon 4G using Tapatalk 2

I believe GinaDees ultimate goal for this forum is to convert it to Magenta everything, based on her negative post history towards everything Sprint and this forum.

[WiWavelength]

I believe GinaDees ultimate goal for this forum is to convert it to Magenta everything. 

 

I do not get the impression that GinaDee is pro T-Mobile as much as "she" is anti Sprint.  If anything, "she" comes across as a shill/troll for AT&T.

 

AJ

[Dfarley]

Oh come on, Neal. You know that I have the upper hand in matters of RF knowledge. And this one is relatively simple. It comes down to differences in the physical layers between the two airlinks.

 

For both CDMA1X and LTE, the base modulation scheme is QPSK, so that puts them roughly at parity. However, CDMA1X is spreading low bit rate voice data across an entire 1.25 MHz broadband carrier, while VoLTE is putting low bit rate voice data in 15 kHz narrowband subcarriers. CDMA1X benefits from spreading gain; LTE does not. Now, that spreading gain is not always efficient, since it trades off high data rates for spreading gain, but it allows CDMA1X to operate at negative SINR. LTE, on the other hand, effectively requires positive SINR.

 

This is fundamental communications theory, Neal. Do you need a refresher on Shannon-Hartley?

 

http://en.wikipedia.org/wiki/Shannon–Hartley_theorem

 

Moreover, empirical research bears this out. Ask hundreds of experienced wireless users here at S4GRU, "Which airlink falters first -- CDMA1X or LTE?" That is practically a rhetorical question. The answer is almost unequivocally "LTE." And I can demonstrate this time after time by hopping in my car and intentionally driving away from Sprint native coverage.

 

Yes, in the end, VoLTE provides some QoS protections. But those protections are still limited by the physical layer of the LTE airlink itself. LTE is very efficient, approaching the Shannon bound, but it does so by trading off robustness for high data rates.

 

AJ

Duh....

[WiWavelength]

Duh....

 

Thanks for sharing my sentiments.

 

 

AJ

[The Dave]

I just want the best network possible for the most reasonable cost. For me, that is Sprint. If buying T-Mobile helps with that goal for a broader customer base, then that is good. I don't care either way. All I know is my bill is reasonable and I get pretty solid coverage. Once 800 mhz becomes more common, I'll be happy. Just as long as I don't have any Magenta splash screens..

[Conan Kudo]

Oh come on, Neal.  You know that I have the upper hand in matters of RF knowledge.  And this one is relatively simple.  It comes down to differences in the physical layers between the two airlinks.

 

For both CDMA1X and LTE, the base modulation scheme is QPSK, so that puts them roughly at parity.  However, CDMA1X is spreading low bit rate voice data across an entire 1.25 MHz broadband carrier, while VoLTE is putting low bit rate voice data in 15 kHz narrowband subcarriers.  CDMA1X benefits from spreading gain; LTE does not.  Now, that spreading gain is not always efficient, since it trades off high data rates for spreading gain, but it allows CDMA1X to operate at negative SINR.  LTE, on the other hand, effectively requires positive SINR.

 

This is fundamental communications theory, Neal.  Do you need a refresher on Shannon-Hartley?

 

http://en.wikipedia.org/wiki/Shannon–Hartley_theorem

 

Moreover, empirical research bears this out.  Ask hundreds of experienced wireless users here at S4GRU, "Which airlink falters first -- CDMA1X or LTE?"  That is practically a rhetorical question.  The answer is almost unequivocally "LTE."  And I can demonstrate this time after time by hopping in my car and intentionally driving away from Sprint native coverage. 

 

Yes, in the end, VoLTE provides some QoS protections.  But those protections are still limited by the physical layer of the LTE airlink itself.  LTE is very efficient, approaching the Shannon bound, but it does so by trading off robustness for high data rates.

 

AJ

I am aware of this, but the key factor of Shannon-Hartley and virtually any property of wireless is the power levels used. For example, one vendor's CDMA/LTE gear supports up to 20W for CDMA 1X and 60W for LTE, but when both are being used, LTE is limited to 20W. That same vendor's UMTS/LTE gear allows up to 80W for UMTS and LTE simultaneously. All things equal, you are correct. But if an "overlay" or secondary network did not share radio paths with the CDMA network, LTE can use higher power levels. Sprint does not do this with ESMR or PCS, but it will do this with BRS+EBS.

 

And I expect that you know that power levels are a critical deciding factor in coverage.

 

And you know very well that there are ways to work around limitations in power levels, even without more cell sites. 

[The Dave]

A Mr Fusion?

[cdk]

A Mr Fusion?

[utiz4321]

I am aware of this, but the key factor of Shannon-Hartley and virtually any property of wireless is the power levels used. For example, one vendor's CDMA/LTE gear supports up to 20W for CDMA 1X and 60W for LTE, but when both are being used, LTE is limited to 20W. That same vendor's UMTS/LTE gear allows up to 80W for UMTS and LTE simultaneously. All things equal, you are correct. But if an "overlay" or secondary network did not share radio paths with the CDMA network, LTE can use higher power levels. Sprint does not do this with ESMR or PCS, but it will do this with BRS+EBS.

 

And I expect that you know that power levels are a critical deciding factor in coverage.

 

And you know very well that there are ways to work around limitations in power levels, even without more cell sites.

Correct me if I am wrong but another problem VoLte is that a call requires more spectrum resources to place than 1x and a great deal more 1xadvanced.

[Conan Kudo]

Correct me if I am wrong but another problem VoLte is that a call requires more spectrum resources to place than 1x and a great deal more 1xadvanced.

VoLTE uses at most 64 Kbps for voice. For video, it uses no more than 1 Mbps. However, current deployments of VoLTE will use 16 Kbps of bandwidth. Latency is the key factor, and VoLTE demands below 150ms of IP latency. On a bits per Hertz level, VoLTE is fantastically more efficient than CDMA 1X-A at the same voice codec bit rate.

[COZisBack]

Let me first start by saying, I have not read through all 20 pages on this thread. I have the first three and the last two, but I get the gist of how it's been going. I'm not going to say anything groundbreaking but just want to cover some things from my opinion.

 

There has been some discussion about Sprint's lack of innovation and acquiring T-Mo would remove that innovation, "since the only thing Sprint has ever came out with that has been innovative to the industry has been Unlimited Data." Please remember, Sprint introduced Unlimited Nights Nationally starting at 7PM for $5, 6PM for $10, which later became Free 7PM. They also brought you Unlimited Mobile-to-Mobile across carriers. I'm sure there are others we've already taken for granted.

 

I appreciate some of the changes that T-Mo has done, but being honest, nothing they have done has enticed me. I HATE paying full price for a phone, no matter how/when I have to pay for it, now or later. Sign me up for a contract I don't care. I want the latest the earliest I can get it and the cheapest I can get it. I end up signing a new 2 year contract every year with DirecTV because I want something new at a very cheap or free price. T-Mo's cheap plans, well let me tell you this, you can get a lot of anything for cheap, doesn't mean it's worth anything. Not saying Sprint's is worth anything yet. Please don't bring up, unlimited international roaming. Only time I'm international is on vacation and guess what I don't want to be doing on vacation.

 

Now to bring up a failed Nextel merger. As a former original Nextel employee, I loved my company. Didn't want to merge with Sprint, just thought our Integrity and Image were superior. We were niche and valued. With that said, the end days were coming. Outdated tech with no way of moving forward, but had extremely loyal subscribers. So as a company (Sprint) acquiring Nextel, how do you manage to bring Nextel to the future on a dead network with demanding loyal customers? You couldn't and Sprint did a piss poor job of making it work, but it is what it is. T-Mobile's network is far from dead and T-Mobile and they don't provide an experience (Direct Connect) Sprint doesn't have the capability to provide and mimic through a rate plan option.

 

Lastly, I say all this, undecided if a SprinT-mo merger would be great for the U.S. Mobile market, but let me tell you this. This isn't Canada! This 'Merica JACK!

[WiWavelength]

I am aware of this, but the key factor of Shannon-Hartley and virtually any property of wireless is the power levels used. For example, one vendor's CDMA/LTE gear supports up to 20W for CDMA 1X and 60W for LTE, but when both are being used, LTE is limited to 20W. That same vendor's UMTS/LTE gear allows up to 80W for UMTS and LTE simultaneously. All things equal, you are correct. But if an "overlay" or secondary network did not share radio paths with the CDMA network, LTE can use higher power levels. Sprint does not do this with ESMR or PCS, but it will do this with BRS+EBS.

 

And I expect that you know that power levels are a critical deciding factor in coverage.

 

And you know very well that there are ways to work around limitations in power levels, even without more cell sites. 

 

Two things...

 

First, power is integrated over bandwidth.  A 1.25 MHz CDMA1X carrier at 20 W and a 5 MHz W-CDMA carrier at 80 W have basically the same power in W/Hz (e.g. 0.000016 W or -18 dBm).  So, I am not surprised by some of the figures you cite.

 

Next, downlink power may be the key factor in broadcast communications but not in two way communications.  The latter uses a link budget to balance the downlink and uplink.  Throwing more power at the downlink does nothing if the mobile device lacks sufficient power to respond in kind.  To use some hyperbole, a site can increase its transmitter power to send a signal to the Moon, but that does not mean a typically power limited mobile device can maintain a connection.  That increased downlink power is wasted and just adds to interference elsewhere.

 

AJ

[WiWavelength]

 

A Mr Fusion?

 

 

I will have a soy latte with two shots of deuterium, please.

 

AJ

[Conan Kudo]

Two things...

 

First, power is integrated over bandwidth.  A 1.25 MHz CDMA1X carrier at 20 W and a 5 MHz W-CDMA carrier at 80 W have basically the same power in W/Hz (e.g. 0.000016 W or -18 dBm).  So, I am not surprised by some of the figures you cite.

 

Next, downlink power may be the key factor in broadcast communications but not in two way communications.  The latter uses a link budget to balance the downlink and uplink.  Throwing more power at the downlink does nothing if the mobile device lacks sufficient power to respond in kind.  To use some hyperbole, a site can increase its transmitter power to send a signal to the Moon, but that does not mean a typically power limited mobile device can maintain a connection.  That increased downlink power is wasted and just adds to interference elsewhere.

 

AJ

That is true. And you are right that reception doesn't mean much if you can not transmit powerfully enough for the cell site to receive it. I was basically trying to prove that there's a power problem when it comes to CDMA/LTE gear.

 

20W over 1.25MHz bandwidth is functionally equivalent to 80W over 5MHz bandwidth, but 20W over 5MHz bandwidth is weaker than 20W over 1.25MHz bandwidth, is it not? And yes, I know there's some bending of this rule with LTE, since it uses subcarriers, but the principle should basically hold true, ne?

 

And this causes the reception problem that many of you experience.

[Mobilesolutions]

I am aware of this, but the key factor of Shannon-Hartley and virtually any property of wireless is the power levels used. For example, one vendor's CDMA/LTE gear supports up to 20W for CDMA 1X and 60W for LTE, but when both are being used, LTE is limited to 20W. That same vendor's UMTS/LTE gear allows up to 80W for UMTS and LTE simultaneously. All things equal, you are correct. But if an "overlay" or secondary network did not share radio paths with the CDMA network, LTE can use higher power levels. Sprint does not do this with ESMR or PCS, but it will do this with BRS+EBS.

 

And I expect that you know that power levels are a critical deciding factor in coverage.

 

And you know very well that there are ways to work around limitations in power levels, even without more cell sites.

 

There are many work-arounds, but what's the point? Can the 2 voice ecosystems not coexist under one operator? Sprint's 800MHz voice is likely to be the most superior vocal communication network in history, and for sake of ROI it's safe to say that a combined Sprint/T-mobile entity would use the HSPA-42 network as a kickback for the forseeable future. VoLTE is the future for city folks, in dense areas it is the efficient solution to handle mass voice traffic, but if you have a cabin on MT. Shasta you will likely be reliant on the more ancient 1X signals to carry your calls.

-William

[Conan Kudo]

There are many work-arounds, but what's the point? Can the 2 voice ecosystems not coexist under one operator? Sprint's 800MHz voice is likely to be the most superior vocal communication network in history, and for sake of ROI it's safe to say that a combined Sprint/T-mobile entity would use the HSPA-42 network as a kickback for the forseeable future. VoLTE is the future for city folks, in dense areas it is the efficient solution to handle mass voice traffic, but if you have a cabin on MT. Shasta you will likely be reliant on the more ancient 1X signals to carry your calls.

-William

I never said that they couldn't. In fact, I expect 1X voice to persist under ESMR, because there's no point in getting rid of it and it could be useful. ESMR LTE, ESMR CDMA 1X-A, PCS GSM (for M2M), PCS HSPA+42, PCS G LTE, AWS LTE, and BRS+EBS LTE could all coexist just fine. 

[S4GRU]

Here is a topic:

 

If Sprint-T-Mobile comes to fruition, the combined operator will likely rebrand.  What will be the new name?

 

Discuss...

 

AJ

 

Being a Dave Barry reader, I like the thought of Penultimate Wireless...

 

ROFLMAO  

Robert

[S4GRU]

I'm late to this discussion.  I got way behind in this thread.  But who in their right mind would want to give up Tmo AWS spectrum for equal amounts of EBS?  EBS is leased, with no guarantee that you can renew it, or renew it for reasonable terms.  If you have to divest, you divest EBS over AWS every time.  And don't even get me started about the propagation benefit.

 

Also, if Sprint buys Tmo, they will have inherited MILLIONS of customers it would want AND NEED to keep.  They need to keep that AWS ecosystem alive for a long time to keep them happy.  You can make sure they become less and less dependent on it over a realtively short period.  However, Sprint will not be divesting AWS en toto to make this deal happen.  No way.  And the FCC wouldn't allow them to kick millions of subs to the curb that way anyway.

 

Robert

[COZisBack]

Being a Dave Barry reader, I like the thought of Penultimate Wireless...

 

ROFLMAO  

Robert

 

I'm going with SprinT-Mo as the "Bennifer" name until decided.

[WiWavelength]

I'm late to this discussion.  I got way behind in this thread.

Can we come down to the office and cheer you on? Go, thread reader, go!

 

AJ

[S4GRU]

Can we come down to the office and cheer you on? Go, thread reader, go!

 

AJ

 

Ahh, brings a smile to my face.  I'd watch some Brian Regan now, but my new job is not conducive to such behaviors!  

 

Robert

[dnicekid]

I'm going with SprinT-Mo as the "Bennifer" name until decided.

x2 that should be the name until the actual merging is done... once it is done they should call it .......

NexG!

next generation wireless!

[mozamcrew]

I'm late to this discussion.  I got way behind in this thread.  But who in their right mind would want to give up Tmo AWS spectrum for equal amounts of EBS?  EBS is leased, with no guarantee that you can renew it, or renew it for reasonable terms.  If you have to divest, you divest EBS over AWS every time.  And don't even get me started about the propagation benefit.

 

Also, if Sprint buys Tmo, they will have inherited MILLIONS of customers it would want AND NEED to keep.  They need to keep that AWS ecosystem alive for a long time to keep them happy.  You can make sure they become less and less dependent on it over a realtively short period.  However, Sprint will not be divesting AWS en toto to make this deal happen.  No way.  And the FCC wouldn't allow them to kick millions of subs to the curb that way anyway.

 

Robert

 

I agree that the EBS spectrum would ideal for divestment if all you needed to do was get below some arbitrary amount of Mhz owned/leased. It's leased instead of owned (higher ongoing costs), it's not all contiguous (less useful), it's a huge swath of spectrum (so you could reduce your Mhz held by just canceling a bunch of leases), and not as many carriers will support LTE on it compared with PCS or AWS (less useful asset in roaming deals). I don't think divesting EBS spectrum will help them with the FCC though, which is the reason WHY they need to divest this stuff in the first place. IIRC, EBS doesn't count against the spectrum screen, just the 55 or so Mhz of BRS they own, thus "divesting" that leased EBS doesn't help you with the FCC. (someone feel free to correct me if I'm wrong about this). 

 

If just axing a ton of EBS gets you nowhere with the FCC, what other divestment options do you have? Absolutely NO WAY they give up their tiny slice of 800 Mhz spectrum, or the BRS spectrum they own. TD-LTE and 800Mhz are too crucial to their long term goals. That leaves you with AWS from TMUS and the combined PCS spectrum.

 

I'm guessing Sprint would prefer to divest the AWS before PCS. Only because they can integrate the PCS spectrum into NV for less than AWS. They have very similar propagation and international roaming support. 

[S4GRU]

Any divestiture of spectrum that counts in the screen is going to be painful, no matter which way you choose.  SMR, PCS, AWS.  It's all painful.

 

Robert