Sprint PCS - Re: Comparing Verizon vs Cingular

Author

Re: Comparing Verizon vs Cingular

Mij Adyaw

2006-07-12, 10:33 am

Why does Sprint have better sound quality than Verizon? I have noticed this
on several different phone models. Does Sprint use a different codec?

"Thomas T. Veldhouse" <veldy71@yahoo.com> wrote in message
news:EtGdnW04V53PkCj
ZnZ2dnUVZ_qidnZ2d@gi
ganews.com...
> In alt.cellular.verizon paulmurray1 <paulmurray1@cox.net> wrote:
>
> Indeed, because GSM carriers don't typically use noise cancellation
> hardware
> and codecs. The advantage is a more natural sound. The disadvantage can
> be
> that somebody talking in a windy or noisy environment may have so much
> background noise that they can not be heard very well. Since cellular
> technology was designed for outdoor use (that seems to be changing
> though), it
> makes sense to have the noise cancellation in place ... so from that point
> of
> view, you could say that current GSM implementations are lacking.
>
> In short, I agree with you that most GSM phones have better sound quality.
>
> --
> Thomas T. Veldhouse
> Key Fingerprint: 2DB9 813F F510 82C2 E1AE 34D0 D69D 1EDC D5EC AED1
>

John Navas

2006-07-12, 12:33 pm

On Wed, 12 Jul 2006 08:03:12 -0700, "Mij Adyaw" <mij@TheBitBucket.com>
wrote in <Qa8tg.11448$Nv.7700@fed1read10>:

>Why does Sprint have better sound quality than Verizon? I have noticed this
>on several different phone models. Does Sprint use a different codec?

The biggest difference comes from network load, since CDMA call quality
degrades as network load increases. Verizon tends to have higher
network load in more areas than Sprint, giving Sprint the edge in call
quality in those areas, but it's just the opposite in other areas (like
the Tri-Valley part of the SF Bay Area, where Sprint has the worst call
quality of any major carrier).

An advantage of GSM over CDMA is that call quality isn't affected by
network load.

--
Best regards, SEE THE FAQ FOR CINGULAR WIRELESS AT
John Navas <http://en.wikibooks.org/wiki/ Cingu...less_FA
Q>

Beavis

2006-07-12, 12:33 pm

In article < q79ab2hhd5n05e5emvm6
2sih6rn3isigp8@4ax.com>,
John Navas < spamfilter0@navasgro
up.com> wrote:

> An advantage of GSM over CDMA is that call quality isn't affected by
> network load.

True. But on the other hand, a CDMA tower can allow more handsets to
make decent calls, without getting a "network busy" message, as I used
to get with AT&T (TDMA) constantly.

Thomas T. Veldhouse

2006-07-12, 3:33 pm

In alt.cellular.verizon Mij Adyaw <mij@thebitbucket.com> wrote:
> Why does Sprint have better sound quality than Verizon? I have noticed this
> on several different phone models. Does Sprint use a different codec?
>

I really don't know, but I assume so.

--
Thomas T. Veldhouse
Key Fingerprint: 2DB9 813F F510 82C2 E1AE 34D0 D69D 1EDC D5EC AED1

John Navas

2006-07-12, 3:33 pm

On Wed, 12 Jul 2006 17:13:06 GMT, Beavis <nobody@nowhere.com> wrote in
<nobody-0B5BA8.13130112072006@news-server.nycap.rr.com>:

>In article < q79ab2hhd5n05e5emvm6
2sih6rn3isigp8@4ax.com>,
> John Navas < spamfilter0@navasgro
up.com> wrote:
>
>
>True. But on the other hand, a CDMA tower can allow more handsets to
>make decent calls, without getting a "network busy" message, as I used
>to get with AT&T (TDMA) constantly.

GSM is more efficient than D-AMPS ("TDMA"), with spectral efficiency
that's roughly comparable to CDMA.

--
Best regards, SEE THE FAQ FOR CINGULAR WIRELESS AT
John Navas <http://en.wikibooks.org/wiki/ Cingu...less_FA
Q>

SMS

2006-07-12, 3:33 pm

Beavis wrote:
> In article < q79ab2hhd5n05e5emvm6
2sih6rn3isigp8@4ax.com>,
> John Navas < spamfilter0@navasgro
up.com> wrote:
>
>
> True. But on the other hand, a CDMA tower can allow more handsets to
> make decent calls, without getting a "network busy" message, as I used
> to get with AT&T (TDMA) constantly.

If you're stationary, then on GSM/TDMA you can at least be assured that
your call quality won't go down during the call. However if you're
moving, and you move into a cell that is at capacity, your call drops.
Dropped calls have been a big problem on Cingular, which is why they
added so many new towers, and why they now are advertising that they've
solved the dropped call issue.

Glenn

2006-07-12, 3:33 pm

John Navas wrote:
>
> GSM is more efficient than D-AMPS ("TDMA"), with spectral efficiency
> that's roughly comparable to CDMA.
>

However, high spectral efficiency is contrary to maximizing information
throughput. The Shannon equation, C=B*log2(S/N+1), shows that to
maximize information capacity and/or minimize required S/N of a channel,
one needs to use more rather than less B (spectrum). Thus when spectral
efficiency goes down, information (call) delivery goes up.

If one is limited by available spectrum, as are the carriers (and dialup
telephone lines) increasing spectral efficiency may make business sense.
However, it doesn't make purely technical sense if the goal is to
maximize capacity/coverage. For that, you want to spread the signal as
wide as is possible, with resulting performance approaching the Shannon
limit.

Glenn

Thomas T. Veldhouse

2006-07-12, 3:33 pm

In alt.cellular.cingular John Navas < spamfilter0@navasgro
up.com> wrote:
>
> GSM is more efficient than D-AMPS ("TDMA"), with spectral efficiency
> that's roughly comparable to CDMA.
>

Hmm ... a contentious arguement at best. Doing what you do best, I submit to
Google and find:

"Spectral Efficiency

Channel capacity in a TDMA system is fixed and indisputable. Each channel
carries a finite number of "slots", and you can never accommodate a new caller
once each of those slots is filled. Spectral efficiency varies from one
technology to another, but computing a precise number is still a contentious
issue. For example, GSM provides 8 slots in a channel 200 kHz wide, while iDEN
provides 3 slots in a channel only 25 kHz wide. GSM therefore consumes 25 kHz
per user, while IS-136 consumes only 8.333 kHz per user. When Direct Connect
is used on iDEN, 6 users can be stuffed into a single channel, thus only 4.166
kHz is consumer per user. There is also a new 6:1 interconnect CODEC coming
for iDEN which will allow 6 phone users per channel.

One would be sorely tempted to proclaim that iDEN has 3 to 6 times the
capacity of GSM. In a one-cell system this is certainly true, but once we
start deploying multiple cells and channel reuse the situation becomes more
complex. Due to GSM's better error management and frequency hopping the
interference of a co-channel site is greatly reduced. This allows frequencies
to be reused more frequently without a degradation in the overall quality of
the service.

Capacity is measured in "calls per cell per MHz". An GSM system using N=4
reuse (this means you have 4 different sets of frequencies to spread out
around town) the figure is 5.0 We get an efficiency value of 6.6 for N=3.
Unfortunately I could not find any figures for iDEN systems, but based on
similar figures released for the IS-136 system we can expect efficiency values
of 6.0 to 10.0.

Computing this figure for CDMA requires that certain assumptions are made.
Formulas have been devised, and using very optimistic assumptions CDMA can
provide a whopping 45 users per cell per MHz. However, when using more
pessimistic (and perhaps more realistic) assumptions, the value is 12. That
still gives CDMA an almost 2:1 advantage over GSM, but questionable advantage
over a well-implement iDEN system."

http://www.arcx.com/sites/CDMAvsTDMA.htm

This article is about two years old, so perhaps some things have changed ...
as they always do. However, looking back in time, your litany remains the
same, so if agree that this information was accurate two years ago, then what
you were saying two years ago is suspect. So, is information given here
invalid?

http://tinyurl.com/k9lep ... an argument older than the article minimizing
the differences between CDMA and GSM when it comes to spectral efficiency.

--
Thomas T. Veldhouse
Key Fingerprint: 2DB9 813F F510 82C2 E1AE 34D0 D69D 1EDC D5EC AED1

SMS

2006-07-12, 3:33 pm

Glenn wrote:
> John Navas wrote:
>
> However, high spectral efficiency is contrary to maximizing information
> throughput. The Shannon equation, C=B*log2(S/N+1), shows that to
> maximize information capacity and/or minimize required S/N of a channel,
> one needs to use more rather than less B (spectrum). Thus when spectral
> efficiency goes down, information (call) delivery goes up.
>

CDMA is much more efficient at the use of spectrum than GSM. Here is the
table of Spectral Efficiencies from the study by Deutsche Bank Securities.

Users per 5 Mhz Relative to AMPS
Min Max Min Max
--- --- --- ---
AMPS 8 8 1.0x 1.0x
GSM 21 23 2.6x 2.9x
TDMA 24 24 3.0x 3.0x
GSM w/AMR 28 34 3.5x 4.3x
GSM FFR w/AMR 34 53 4.3x 6.6x
CDMA (IS-95A) 51 66 6.4x 8.3x
CDMA2000 1X 105 120 13.1x 15.0x
W-CDMA 62 95 7.8x 11.9x

Mij Adyaw

2006-07-12, 3:33 pm

Cingular states that they have an independent study that they have the
fewest dropped calls of any wireless provider.
(any most pigs are capable of flight too)

"SMS" <scharf.steven@geemail.com> wrote in message
news:44b5471a$0$9617
2$742ec2ed@news.sonic.net...
> Beavis wrote:
>
> If you're stationary, then on GSM/TDMA you can at least be assured that
> your call quality won't go down during the call. However if you're moving,
> and you move into a cell that is at capacity, your call drops. Dropped
> calls have been a big problem on Cingular, which is why they added so many
> new towers, and why they now are advertising that they've solved the
> dropped call issue.

John Navas

2006-07-12, 3:33 pm

On Wed, 12 Jul 2006 12:16:29 -0700, Glenn <this@isnt.it> wrote in
< 44b54b15$0$34499$742
ec2ed@news.sonic.net>:

>John Navas wrote:
>
>However, high spectral efficiency is contrary to maximizing information
>throughput. The Shannon equation, C=B*log2(S/N+1), shows that to
>maximize information capacity and/or minimize required S/N of a channel,
>one needs to use more rather than less B (spectrum). Thus when spectral
>efficiency goes down, information (call) delivery goes up.
>
>If one is limited by available spectrum, as are the carriers (and dialup
>telephone lines) increasing spectral efficiency may make business sense.
>However, it doesn't make purely technical sense if the goal is to
>maximize capacity/coverage. For that, you want to spread the signal as
>wide as is possible, with resulting performance approaching the Shannon
>limit.

My comments are based on real-world Erlangs, not Shannon theory.

--
Best regards, SEE THE FAQ FOR CINGULAR WIRELESS AT
John Navas <http://en.wikibooks.org/wiki/ Cingu...less_FA
Q>

John Navas

2006-07-12, 3:33 pm

On Wed, 12 Jul 2006 12:01:40 -0700, SMS <scharf.steven@geemail.com>
wrote in < 44b5471a$0$96172$742
ec2ed@news.sonic.net>:

>Beavis wrote:
>
>If you're stationary, then on GSM/TDMA you can at least be assured that
>your call quality won't go down during the call. However if you're
>moving, and you move into a cell that is at capacity, your call drops.

True, but that's extremely rare. Just as CDMA calls can be degraded to
unusability or dropped because of cell "breathing" under load, one of a
number of CDMA problems. In practice, these aren't significant issues.

>Dropped calls have been a big problem on Cingular,

Not true.

>which is why they
>added so many new towers,

That's to increase coverage. It has little to do with existing network
capacity.

>and why they now are advertising that they've
>solved the dropped call issue.

That's not what they are advertising -- that's your anti-Cingular spin.

--
Best regards, SEE THE FAQ FOR CINGULAR WIRELESS AT
John Navas <http://en.wikibooks.org/wiki/ Cingu...less_FA
Q>

John Navas

2006-07-12, 3:33 pm

On Wed, 12 Jul 2006 12:41:49 -0700, SMS <scharf.steven@geemail.com>
wrote in < 44b55083$0$96164$742
ec2ed@news.sonic.net>:

>Glenn wrote:
>
>CDMA is much more efficient at the use of spectrum than GSM. Here is the
>table of Spectral Efficiencies from the study by Deutsche Bank Securities.

Which has a well-known axe to grind in favor of CDMA. :)

> Users per 5 Mhz Relative to AMPS
> Min Max Min Max
> --- --- --- ---
>AMPS 8 8 1.0x 1.0x
>GSM 21 23 2.6x 2.9x
>TDMA 24 24 3.0x 3.0x
>GSM w/AMR 28 34 3.5x 4.3x
>GSM FFR w/AMR 34 53 4.3x 6.6x
>CDMA (IS-95A) 51 66 6.4x 8.3x
>CDMA2000 1X 105 120 13.1x 15.0x
>W-CDMA 62 95 7.8x 11.9x

<http://www.3gsmamericas.com/pdfs/ p... t_want_not.pdf>:

In a real-world environment, a well-engineered TDMA system can handle
about 37 Erlangs per sector, while a comparable GSM system handles
about 67 Erlangs - or roughly 45% more than TDMA. That boost alone is
enough for most TDMA operators to make a business case for switching
to GSM, but a new voice-coding technology, currently available, more
than doubles GSM’s capacity to 142 Erlangs, which is nearly four
times as much as TDMA.

GSM gains that fourfold advantage from adaptive multi-rate speech
transcoding (AMR), which adjusts the voice-coding rates according to
changing channel conditions, such as decreasing signal strength or
rising interference. ...

GSM operators should start reaping the benefits of AMR by mid 2003
...

Although CDMA operators and vendors always touted their 2G technology
as being almost exponentially more spectrally efficient than Advanced
Mobile Phone System (AMPS), GSM and TDMA, that promise did not always
hold up in the real world. An example is the bold claim made by CDMA
vendors in the mid 1990s that their technology has 20 to 30 times
more capacity than AMPS. When CDMA systems started to be deployed a
few years later, the gain turned out to be only five to six times
better than AMPS. When EVRC was eventually added, the gain increased
again - but still nowhere near the original claim of 20 to 30 times.

Many CDMA operators are currently in the midst of deploying 1XRTT, an
interim step towards 3G that promises to use spectrum more
efficiently. Time will tell whether that is the truth but the fact is
that, based on BEST-CASE DATA from CDMA vendors, 1XRTT with EVRC
handles up to 156 Erlangs per sector. Bearing in mind that GSM with
AMR handles 142 Erlangs, IT IS A GREAT STRETCH TO ARGUE THAT 1XRTT
HAS A MAJOR ADVANTAGE OVER GSM.... [emphasis added]

... Thus, while one technology may have SLIGHTLY HIGHER CAPACITY
GAINS at one point in time, another technology is always preparing to
leap-frog over it. [emphasis added]

--
Best regards, SEE THE FAQ FOR CINGULAR WIRELESS AT
John Navas <http://en.wikibooks.org/wiki/ Cingu...less_FA
Q>

John Navas

2006-07-12, 3:33 pm

On Wed, 12 Jul 2006 14:22:57 -0500, "Thomas T. Veldhouse"
<veldy71@yahoo.com> wrote in
< o9mdnVwDfYmM0SjZnZ2d
nUVZ_sSdnZ2d@giganew
s.com>:

>In alt.cellular.cingular John Navas < spamfilter0@navasgro
up.com> wrote:
>
>Hmm ... a contentious arguement at best. Doing what you do best, I submit to
>Google and find:
>[SNIP]

<http://www.3gsmamericas.com/pdfs/ p... t_want_not.pdf>:

In a real-world environment, a well-engineered TDMA system can handle
about 37 Erlangs per sector, while a comparable GSM system handles
about 67 Erlangs - or roughly 45% more than TDMA. That boost alone is
enough for most TDMA operators to make a business case for switching
to GSM, but a new voice-coding technology, currently available, more
than doubles GSM’s capacity to 142 Erlangs, which is nearly four
times as much as TDMA.

GSM gains that fourfold advantage from adaptive multi-rate speech
transcoding (AMR), which adjusts the voice-coding rates according to
changing channel conditions, such as decreasing signal strength or
rising interference. ...

GSM operators should start reaping the benefits of AMR by mid 2003
...

Although CDMA operators and vendors always touted their 2G technology
as being almost exponentially more spectrally efficient than Advanced
Mobile Phone System (AMPS), GSM and TDMA, that promise did not always
hold up in the real world. An example is the bold claim made by CDMA
vendors in the mid 1990s that their technology has 20 to 30 times
more capacity than AMPS. When CDMA systems started to be deployed a
few years later, the gain turned out to be only five to six times
better than AMPS. When EVRC was eventually added, the gain increased
again - but still nowhere near the original claim of 20 to 30 times.

Many CDMA operators are currently in the midst of deploying 1XRTT, an
interim step towards 3G that promises to use spectrum more
efficiently. Time will tell whether that is the truth but the fact is
that, based on BEST-CASE DATA from CDMA vendors, 1XRTT with EVRC
handles up to 156 Erlangs per sector. Bearing in mind that GSM with
AMR handles 142 Erlangs, IT IS A GREAT STRETCH TO ARGUE THAT 1XRTT
HAS A MAJOR ADVANTAGE OVER GSM.... [emphasis added]

... Thus, while one technology may have SLIGHTLY HIGHER CAPACITY
GAINS at one point in time, another technology is always preparing to
leap-frog over it. [emphasis added]

--
Best regards, SEE THE FAQ FOR CINGULAR WIRELESS AT
John Navas <http://en.wikibooks.org/wiki/ Cingu...less_FA
Q>

Thomas T. Veldhouse

2006-07-12, 3:33 pm

In alt.cellular.verizon John Navas < spamfilter0@navasgro
up.com> wrote:
> On Wed, 12 Jul 2006 14:22:57 -0500, "Thomas T. Veldhouse"
> <veldy71@yahoo.com> wrote in
> < o9mdnVwDfYmM0SjZnZ2d
nUVZ_sSdnZ2d@giganew
s.com>:
>
>

So, you fail to indicate whether you agree or disagree with the clipped
article that I posted.

--
Thomas T. Veldhouse
Key Fingerprint: 2DB9 813F F510 82C2 E1AE 34D0 D69D 1EDC D5EC AED1

John Navas

2006-07-12, 3:33 pm

On Wed, 12 Jul 2006 15:13:45 -0500, "Thomas T. Veldhouse"
<veldy71@yahoo.com> wrote in
< n5udnQL8GoFkyijZnZ2d
nUVZ_r-dnZ2d@giganews.com>:

>In alt.cellular.verizon John Navas < spamfilter0@navasgro
up.com> wrote:
>
>So, you fail to indicate whether you agree or disagree with the clipped
>article that I posted.

Again, you have the last word -- this is clearly a pointless debate.

--
Best regards, SEE THE FAQ FOR CINGULAR WIRELESS AT
John Navas <http://en.wikibooks.org/wiki/ Cingu...less_FA
Q>

Glenn

2006-07-12, 3:33 pm

John Navas wrote:
>
>
> My comments are based on real-world Erlangs, not Shannon theory.
>

And Shannon is based on physics which is by definition, "real world".

All I was saying is that equating good (high) spectral efficiency with
high coverage/capacity is wrong. Everything else equal (which it never
is) the system which spreads its transmitter power the MOST, thus
yielding the lowest spectral efficiency, achieves the highest
information capacity.

Business concerned with limited spectrum tend to be concerned about
spectral efficiency, systems which are trying to maximize performance
try to minimize spectral efficiency. It's real-world physics and applies
to everyone.

Glenn

John Navas

2006-07-12, 10:33 pm

On Wed, 12 Jul 2006 13:15:17 -0700, Glenn <this@isnt.it> wrote in
< 44b558de$0$34507$742
ec2ed@news.sonic.net>:

>John Navas wrote:
>
>And Shannon is based on physics which is by definition, "real world".
>
>All I was saying is that equating good (high) spectral efficiency with
>high coverage/capacity is wrong. Everything else equal (which it never
>is) the system which spreads its transmitter power the MOST, thus
>yielding the lowest spectral efficiency, achieves the highest
>information capacity.
>
>Business concerned with limited spectrum tend to be concerned about
>spectral efficiency, systems which are trying to maximize performance
>try to minimize spectral efficiency. It's real-world physics and applies
>to everyone.

What matters in cellular is Erlangs, not theory.

--
Best regards, SEE THE FAQ FOR CINGULAR WIRELESS AT
John Navas <http://en.wikibooks.org/wiki/ Cingu...less_FA
Q>

Glenn

2006-07-12, 10:33 pm

John Navas wrote:
> What matters in cellular is Erlangs, not theory.
>

Both traffic, measured in erlangs, and information capacity, measured in
bps ARE theory. An erlang is a traffic unit used to describe usage,
http://en.wikipedia.org/wiki/Erlang_unit. It does not describe the
overall effectiveness of the system which is providing the service.

When you compared CDMA and GSM systems by saying

"GSM is more efficient than D-AMPS ("TDMA"), with spectral efficiency
that's roughly comparable to CDMA."

you implied that higher spectral efficiency meant a more positive
comparison. I responded by saying that from a technical point of view,
which has practical, real-world application to every carrier and every
modulation system, high spectral efficiency was a negative attribute.

Clearly a comparison of two cellular vendors, as this thread attempts,
is a very complex issue with a great many business, technical and social
issues and factors. Many things may matter, including whether someone
likes the company logo or not.

However when comparing two information systems, more transport is
possible from the system which has the lower spectral efficiency and
this fact has practical consequences for all carriers and information
services.

Glenn

Scott

2006-07-12, 10:33 pm

"John Navas" < spamfilter0@navasgro
up.com> wrote in message
news:mprab29vvtqh5qo
a4cvjidhn6m3d9c846t@
4ax.com...

>
> What matters in cellular is Erlangs, not theory.
>

Silence, worthless earthlings- the Lord God John Navas has spoken. How dare
anybody contradict his word with relevent facts and information?

Scott

2006-07-12, 10:33 pm

"John Navas" < spamfilter0@navasgro
up.com> wrote in message
news:14mab2thp6vfecb
sogmve84n5rk64t5rbr@
4ax.com...
> On Wed, 12 Jul 2006 15:13:45 -0500, "Thomas T. Veldhouse"
> <veldy71@yahoo.com> wrote in
> < n5udnQL8GoFkyijZnZ2d
nUVZ_r-dnZ2d@giganews.com>:
>
>
> Again, you have the last word -- this is clearly a pointless debate.
>

Translation- John got caught again and refuses to admit it.

John Navas

2006-07-12, 10:33 pm

On Wed, 12 Jul 2006 15:48:58 -0700, Glenn <this@isnt.it> wrote in
< 44b57ce2$0$34502$742
ec2ed@news.sonic.net>:

>[SNIP]

I'm not going to go around again pointlessly, so you have the last word.

--
Best regards, SEE THE FAQ FOR CINGULAR WIRELESS AT
John Navas <http://en.wikibooks.org/wiki/ Cingu...less_FA
Q>

DecaturTxCowboy

2006-07-12, 10:33 pm

John Navas wrote:
> What matters in cellular is Erlangs, not theory.

Incorrect. Changeable face plates, ring tones, accessories, and general
"coolness factor" are what really matter if you recall AT&Ts survey.

DecaturTxCowboy

2006-07-12, 10:33 pm

John Navas wrote:
> On Wed, 12 Jul 2006 15:48:58 -0700, Glenn <this@isnt.it> wrote in
> < 44b57ce2$0$34502$742
ec2ed@news.sonic.net>:
>
>
> I'm not going to go around again pointlessly, so you have the last word.

Translation: You are way over my head and I can't argue with you.

Scott

2006-07-12, 10:33 pm

"DecaturTxCowboy" <nono@no.no> wrote in message
news:vqhtg.48070$VE1.34823@newssvr14.news.prodigy.com...
> John Navas wrote:
>
> Translation: You are way over my head and I can't argue with you.

Ooo- I like your transaltion better than mine- it's a much more literal one.

Thomas T. Veldhouse

2006-07-13, 10:33 am

In alt.cellular.cingular John Navas < spamfilter0@navasgro
up.com> wrote:
> On Wed, 12 Jul 2006 15:48:58 -0700, Glenn <this@isnt.it> wrote in
> < 44b57ce2$0$34502$742
ec2ed@news.sonic.net>:
>
>
> I'm not going to go around again pointlessly, so you have the last word.
>

Hmm ... this is starting to sound like a fairly common "John Navas Theme".

--
Thomas T. Veldhouse
Key Fingerprint: 2DB9 813F F510 82C2 E1AE 34D0 D69D 1EDC D5EC AED1

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