View Full Version : CDMA
karthikbalaguru
12-30-07, 09:47 AM
Hi,
In CDMA , a system used in 2G GSM, all radios can be active all the
time.
But, all cannot be active all the time while using TDMA.
Is this the main reason for TDMA failure ?
Karthik Balaguru
karthikbalaguru wrote:
> Hi,
> In CDMA , a system used in 2G GSM, all radios can be active all the
> time.
> But, all cannot be active all the time while using TDMA.
> Is this the main reason for TDMA failure ?
What do you mean by "all (systems?)"?
What do you mean by "failure"?
Are you referring to native TDMA or TDMA enhanced with GSM?
karthikbalaguru
12-31-07, 04:21 AM
On Dec 30, 11:52*pm, DTC <m...@nothingtoseehere.zzx> wrote:
> karthikbalaguru wrote:
> > Hi,
> > In CDMA , a system used in 2G GSM, all radios can be active all the
> > time.
> > But, all cannot be active all the time while using TDMA.
> > Is this the main reason for TDMA failure ?
>
> What do you mean by "all (systems?)"?
I mean to say all radios being active at the same time.
>
> What do you mean by "failure"?
Being overcome by CDMA .
>
> Are you referring to native TDMA or TDMA enhanced with GSM?
TDMA enhanced with GSM.
Thx in advans,
Karthik Balaguru
karthikbalaguru wrote:
>>> In CDMA , a system used in 2G GSM, all radios can be active all the
>>> time.
>>> But, all cannot be active all the time while using TDMA.
>>> Is this the main reason for TDMA failure ?
>> What do you mean by "all (systems?)"?
> I mean to say all radios being active at the same time.
>> What do you mean by "failure"?
> Being overcome by CDMA .
Its really a moot point as TDMA has been replaced for the most part
by GSM.
Now do you mean...??
Are you referring to the fact that a GSM (an evolution of TDMA)
based cell site can only support a finite number of cell phones
where CDMA can support an infinite number (until noise floor
problems bring the total number of users on par with TDMA)?
The fact that both technologies are serving the respective
cellular providers quiet well, it would not appear that
neither technology has any clear and compelling advantage
over the other. Therefore I don't see GSM as a failure.
Considering an equal number of users will swear GSM sounds
better than CDMA and equal number of users will swear CDMA
sounds better than GSM, the argument will go on forever.
Keep in mind, the goal of cellular providers is to increase
the cell site loading to accommodate the greatest number of
users, regardless of the consequences of less audio quality.
karthikbalaguru
12-31-07, 01:25 PM
On Dec 31, 10:55*pm, DTC <m...@nothingtoseehere.zzx> wrote:
> karthikbalaguru wrote:
> >>> In CDMA , a system used in 2G GSM, all radios can be active all the
> >>> time.
> >>> But, all cannot be active all the time while using TDMA.
> >>> Is this the main reason for TDMA failure ?
> >> What do you mean by "all (systems?)"?
> > * *I mean to say all radios being active at the same time.
> >> What do you mean by "failure"?
> > * *Being overcome by CDMA .
>
> Its really a moot point as TDMA has been replaced for the most part
> by GSM.
>
> Now do you mean...??
>
> Are you referring to the fact that a GSM (an evolution of TDMA)
> based cell site can only support a finite number of cell phones
> where CDMA can support an infinite number (until noise floor
> problems bring the total number of users on par with TDMA)?
>
> The fact that both technologies are serving the respective
> cellular providers quiet well, it would not appear that
> neither technology has any clear and compelling advantage
> over the other. Therefore I don't see GSM as a failure.
>
> Considering an equal number of users will swear GSM sounds
> better than CDMA and equal number of users will swear CDMA
> sounds better than GSM, the argument will go on forever.
>
> Keep in mind, the goal of cellular providers is to increase
> the cell site loading to accommodate the greatest number of
> users, regardless of the consequences of less audio quality.
I accept that they serve the needs, but
larger numbers of mobiles can be served by smaller number of cell-
sites
in CDMA-based standards and this will surely have a high economic
advantage over TDMA-based standards.
Karthik Balaguru
karthikbalaguru wrote:
> I accept that they serve the needs, but
> larger numbers of mobiles can be served by smaller number of cell-
> sites
> in CDMA-based standards and this will surely have a high economic
> advantage over TDMA-based standards.
Which would be negated by the TDMA/GSM carriers putting in more
cells of a smaller size. Hardly a significant economic advantage
when both sides have similar deployment costs.
karthikbalaguru
01-01-08, 02:02 PM
On Jan 1, 11:58*am, DTC <m...@nothingtoseehere.zzx> wrote:
> karthikbalaguru wrote:
> > I accept that they serve the needs, but
> > larger numbers of mobiles can be served by smaller number of cell-
> > sites
> > in CDMA-based standards and this will surely have a high economic
> > advantage over TDMA-based standards.
>
> Which would be negated by the TDMA/GSM carriers putting in more
> cells of a smaller size. Hardly a significant economic advantage
> when both sides have similar deployment costs.
I understand your views/points.
But, then.. why did CDMA come into existence ?
Surely, there must be some advantage and difference.
CDMA capacity => 3x the capacity of TDMA
And so, a CDMA system will hold more callers and is more stable.
I think, CDMA has some upperhand because of its core idea and that
could have made it possible for it to overcome TDMA.
It can can share a frequency band with many types of conventional
transmissions with minimal interference. The core idea of Spread
Spectrum
technique has advantages like establishment of secure communications,
increased resistance to natural interference and jamming
and to prevent detection.
Hand-offs might be simpler in TDMA because of non-continuous
transmission.
I am not sure about the dropped calls in either CDMA / TDMA.
But, as CDMA is a new wireless development relative to TDMA, i think,
the dropped calls should be less in CDMA.
What do you think ?
Karthik Balaguru
karthikbalaguru wrote:
> But, then.. why did CDMA come into existence ?
Its been around a long long time in military communications.
> Surely, there must be some advantage and difference.
If the difference was that compelling, GSM would have been dropped
a long tim eago. It wasn't, so there isn't.
> CDMA capacity => 3x the capacity of TDMA
Questionable in practice.
> And so, a CDMA system will hold more callers and is more stable.
Less stable. With GSM/TDMA, the channel is locked to you. With CDMA
you can be dumped unexpectedly from"cell breathing"
> I think, CDMA has some upperhand because of its core idea and that
> could have made it possible for it to overcome TDMA.
Moot point as both technologies may very well be replaced by W-CDMA
eventually. But CDMA was a late comer and its not likely to see
all GSM/TDMA replaced when there is no compelling advantage. Carriers
are quite happy with GSM at the moment.
> But, as CDMA is a new wireless development relative to TDMA, i think,
> the dropped calls should be less in CDMA.
Just because its newer does not automatically mean it will have less
dropped calls. See above reference to "cell breathing".
> What do you think ?
You are looking for someone to write your term paper for you.
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